JP5003797B2 - Work vehicle - Google Patents

Description

The present invention relates to a configuration of an operation switch / lever of a working machine such as a tractor, in particular, a work vehicle to which working machines for agriculture, construction, and transportation are connected.

Work vehicles such as agricultural, construction, and transportation tractors are equipped with levers such as an elevator switch for the work implement, forward / reverse switching of the vehicle, and an accelerator around the steering wheel handle in consideration of operability. . In addition, a meter panel for displaying the amount of fuel and the like is also provided around the handle, and such operation switches and display devices are intensively arranged.

In recent years, with the diversification of work machines, the types of operation switches have increased, and more and more switches have been placed around the handle.
Therefore, depending on the skill level of the operator who operates the work vehicle, an erroneous operation may be caused, or a wrong switch may be touched by mistake, resulting in poor work operability and a reduction in work efficiency.

In order to improve the operability of the operation switches and levers, a forward / reverse switching lever, an accelerator lever, and a lifting / lowering switch lever of the work implement are provided on the dashboard that covers the handle post of the steering handle. The pivot base of the accelerator lever and the lift switch lever of the work implement is placed in front of the handle post, the forward / reverse switch lever protrudes outward from the side of the dashboard, and the accelerator lever is on the opposite side of the forward / backward switch lever. There is known a configuration in which the lift switch lever of the work machine protrudes outward from the side surface of the board and protrudes outward from the upper surface of the dashboard.

JP 2007-11496 A

In the configuration of Patent Document 1, since the forward / reverse switching lever, the accelerator lever, and the lift switch lever of the work machine can be operated in front of the handle post, the space with the seat can be widened to ensure comfort. The accelerator lever and forward / reverse selector lever are arranged to protrude outward from the left and right sides of the dashboard, and the control lever is located on the outer front when both hands are placed on the steering handle, making it easier to grip. It becomes easy to operate.

However, in the configuration of Patent Document 1, the lifting / lowering switch lever of the work machine is a lever for operating only the lifting / lowering of the work machine, and it is necessary to turn on / off the operation control of the work machine with another switch. Therefore, it cannot be said that the operability of the work is improved only by changing the arrangement of the switches and levers as described above, and the operation operation of the work machine still remains complicated.

The subject of this invention is providing the traveling vehicle provided with the operation part (an operation switch, levers, etc.) for improving the operativity of the working machine connected with the work vehicle, and improving work efficiency.

The problems of the present invention are solved by the following means.
The invention according to claim 1 is a work vehicle comprising a steering handle (73) and a cockpit (16) and connected to a work implement (84).
The lifting lever (130) of the working machine (84), which is located in the vicinity of the steering handle (73) and can be operated in two stages in one direction and the other direction, and the lifting lever (130) A control processing device (100) for operating the work machine (84) by processing the operation information when the is operated,
The control processor (100), the incoming or cut operation of the lift lever (130) to one direction or the other to each of the working machine is operated in a first stage (84), the working machine (84 when operated in the inlet side of the actuation of) it lowers to the pre-Symbol working machine (84) operating in a second stage, the second stage is when operating in the cut-side of the operation of the work machine (84) It is configured to perform a process of raising the work machine (84) when operated ,
Specified torque (b) after constituting the PTO clutch (E) for power connection / disconnection to the work machine (84) and subtracting the influence of the centrifugal force of the clutch from the rotational speed of the upper shaft of the PTO clutch (E) And the PTO clutch (E) is connected so that the specified torque (b) is obtained .

For example, when the lifting lever (130) of the work machine (84) is operated to the first stage on the ascending operation side, the power of the work machine (84) is turned off, and when operated to the first stage on the descending operation side, the work machine ( power of 84) ing to enter. Lifting lever (130) is operated to the second-stage elevated operating side Ru raise the working machine (84). The working lever (130) is lowered by operating the elevating lever (130) to the second stage on the lowering operation side.
Then, a specified torque (b) after subtracting the influence of the centrifugal force of the clutch from the rotational speed of the shaft on the upper side of the PTO clutch (E) is calculated, and the PTO clutch (E ).

The invention according to claim 2 is characterized in that a connection sensitivity PTO switch (202) for making the connection of the PTO clutch (E) faster or gentler is configured in the switch box (180). The work vehicle described .

The connection sensitivity PTO switch (202) is used to speed up or loosen the connection of the PTO clutch (E).

According to the first aspect of the present invention, the power of the work implement (84) can be turned on and off by operating the elevating lever (130) of the work implement (84) in two stages, and one elevating lever (130) is provided. By operating, not only raising / lowering but also operation of the power of the work machine (84) can be performed, and the operation space is not increased. Therefore, complicated operations are eliminated, the operability of the work machine (84) is improved, and work efficiency is increased. Further, since the elevating lever (130) is in the vicinity of the steering handle (73), the elevating lever (130) can be operated while operating the steering handle (73), and the operability is excellent. . Also, a specified torque (b) after subtracting the influence of the centrifugal force of the clutch from the rotational speed of the shaft on the upper side of the PTO clutch (E) is calculated, and the PTO clutch (E ), The PTO clutch (E) is smoothly connected.

According to the second aspect of the present invention, the connection sensitivity PTO switch (202) makes the connection of the PTO clutch (E) faster or slower, so that it can be changed according to the work situation.

Embodiments of the present invention will be described below with reference to the drawings. In the present specification, left and right are respectively referred to as left and right in the forward direction of the vehicle, and front and rear are referred to as front and rear, respectively. Here, the left and right traveling axles in the present specification refer to traveling axles in the left and right direction facing the traveling direction of the work vehicle. And according to embodiment of this invention, the case where the rotary plowing apparatus as an example of a working machine is connected with the tractor which is an example of a working vehicle is demonstrated below as an example.

FIG. 1 (a) shows a left side view of a tractor according to an embodiment of the present invention, and FIG. 1 (b) shows a simplified plan view showing the relationship between a mission case, front wheels, and rear wheels. FIG. 2 (a) shows a perspective view of a main part near the right side of the steering handle of the tractor of FIG. 1, and FIG. 2 (b) shows the operating state of the lifting lever of the rotary tiller and the operation of the rotary tiller. The control block diagram for demonstrating is shown. Further, FIG. 3 (a) shows a perspective view of the main part near the armrest on the right side of the cockpit when the switch for raising / lowering is used instead of the lever for raising / lowering, and FIG. 3 (b) shows the raising / lowering of the rotary tiller. The control block diagram for demonstrating the operation state of the switch for operation and the action | operation of a rotary tillage apparatus is shown.

The tractor vehicle body T having the riding mode of riding four-wheel drive travels while steering the front wheels 61 with the steering handle 73. A work implement such as a rotary tillage device 84 or the like can be mounted on the rear portion of the vehicle body T by a three-point link mechanism so as to be able to move up and down. The vehicle body T has an engine 62 mounted on the front end thereof via an engine bracket that is supported on the front axle housing 72, and a clutch housing, a transmission case 65, and the like are integrally connected to the rear side of the engine 62. A rear axle housing 75 is provided at the rearmost part of the case 65, and the rear wheels 63 are mounted on the left and right sides.

The power from the engine 62 is shifted by a transmission in the transmission case 65 and transmitted to the front wheels 61 and the rear wheels 63 to travel. The power transmission mechanism from the engine 62 will be described in detail later. Further, behind the tractor body T, there are various levers such as an elevating lever 130, an accelerator lever 116, a lever 118 (a blinker and a light lever) of the rotary tiller 84, a parking brake warning light 123, an automatic Instruments such as a speed change indicator lamp 124 and a tractor engine tachometer 125 are provided.

The lifting lever 130 of the tractor according to the present embodiment can be operated in two steps (there is a two-click feeling) on the lifting operation side and the lowering operation side with a single touch. The first stage operation is characterized in that the power of the rotary tiller 84 can be turned on or off. In the example shown in FIG. 2, the power of the rotary tiller 84 can be turned off in the first stage operation on the ascending operation side of the lifting lever 130, and the rotary tiller device in the first stage operation on the descending operation side. It is the structure which can enter 84 motive power.

By adopting this configuration, it is possible to operate not only the lifting and lowering but also the power of the working machine such as the rotary tiller 84 by operating one lifting lever 130, so that the operation space is not increased. . Therefore, complicated operations are eliminated, the operability of the work machine is improved, and work efficiency is improved. When the elevating lever 130 is in the vicinity of the steering handle 73, the elevating lever 130 can be operated while operating the steering handle 73 with the right hand (or the left hand), and the operability is excellent.

Further, as shown in FIG. 2B, when the lifting lever 130 is raised from the neutral position to the first stage, the electric signal is transmitted to the controller 100, and the controller 100 transmits the PTO counter shaft 9 (FIG. 4). The upper PTO clutch pack 66 is turned off and the rotation of the PTO shaft 14 stops. Therefore, the power of the rotary tiller 84 is turned off, and the rotary tiller 84 is stopped. The rotary tiller 84 is stopped when the elevating lever 130 is in the neutral position. Even when the elevating lever 130 is raised to the first stage from the neutral position, the stopped state is maintained as it is.

When the elevating lever 130 is further raised to the second stage, the electric signal is transmitted to the controller 100, the controller 100 operates the raising solenoid 136, and the rotary tiller 84 is raised. Further, when the lifting lever 130 is returned to the neutral position and then lowered to the first stage, the controller 100 enters the PTO clutch pack 66 and rotationally drives the PTO shaft 14. Therefore, the power of the rotary tiller 84 is turned on, and the rotary tiller 84 is activated. When the elevating lever 130 is further lowered to the second stage, the descending solenoid 137 is similarly operated by the controller 100 and the rotary tiller 84 is lowered.

Further, the tractor shown in FIG. 1 is provided with a position control lever 190 for controlling the raising / lowering position of the rotary tiller 84 and a lift arm sensor 134 for detecting the raising / lowering position of the rotary tiller 84. From the lift arm sensor 134, a sensor signal is constantly transmitted to the controller 100 of the rotary tiller 84 so that the position of the rotary tiller 84 can be grasped. When the position control lever 190 is operated, the electrical signal is transmitted to the controller 100, and the controller 100 determines that the position of the rotary tiller 84 is based on the operation of the position control lever 190 based on the sensor signal from the lift arm sensor 134. Thus, the position of the rotary tiller 84 can be controlled by operating the ascending solenoid 136 and the descending solenoid 137.

As described above, when the elevating lever 130 is operated to the first stage on the raising operation side, the power of the rotary tiller 84 is turned off, and when operated to the first stage on the lowering operation side, the power of the rotary tiller 84 is turned on. If it does so, after operating the raising / lowering lever 130 to the 2nd step | stage of the raising operation side and raising the rotary tiller 84, if the raising / lowering lever 130 is lowered, rotary tilling will be interlocked with this lowering operation. The power of the device 84 can be turned on, and the elevating lever 130 can be used in various ways for raising and lowering and turning on and off the power.

Since the rotation of the PTO counter shaft 9 can be stopped before the rotary tiller 84 is raised, the rotary tiller 84 can be stopped while being buried in the soil, and an operation for closing the hole after the rotary tillage (hole Can be naturally blocked). In addition, when the rotary tiller 84 is raised without stopping the rotation of the PTO counter shaft 9, a hole (concave portion) after the rotary tillage is generated, but this configuration can prevent such inconvenience. In addition, an operation for stopping in an emergency can be easily performed by operating the elevating lever 130 up to the first stage on the ascending operation side.

Further, the operation of stopping the rotation of the PTO counter shaft 9 and turning off the power of the rotary tiller 84 (operation to the first stage on the raising operation side) is the raising operation position of the rotary tiller 84 (the first operation on the raising operation side). Since it can be performed at a timing earlier than the operation in the second stage, the operability is excellent. For example, in order to stop the rotation of the PTO counter shaft 9 with the rotary tiller 84 lowered, it is necessary to release the steering handle 73 and operate the PTO on / off switch 187 (FIG. 3). Can be omitted.

Further, when the lifting lever 130 is lowered to the first stage, the power of the rotary tiller 84 is turned on, and when the lifting lever 130 is lowered to the second stage, the rotary tiller 84 is lowered. Thus, the operation for rotating the PTO counter shaft 9 to turn on the power of the rotary tiller 84 is arranged in the first stage on the lowering operation side, and the operation for lowering the rotary tiller 84 is the second on the lowering operation side. When arranged at the stage, the rotary tiller 84 is already in operation when the rotary tiller 84 is lowered. Therefore, since the rotary tiller 84 can be rotated before the rotary tiller 84 enters the soil, the tillage work can be performed immediately compared to the case where the rotary tiller 84 is lowered and then operated, so that the operability is good. Excellent in properties.

FIG. 3 shows an example in which the lift switch 191 is used instead of the lift lever 130. When the raising / lowering switch 191 is provided on the armrest 30 on the right side of the cockpit 16, the switch can be operated when the right hand is placed on the armrest 30, and the operability is excellent. As shown in FIG. 3, the lifting switch 191 is a seesaw type two-stage switch. When the rear side (the raising operation side) is pushed from the neutral position to the first stage, the controller 100 is similar to the case of FIG. The PTO clutch pack 66 on the PTO counter shaft 9 (FIG. 4) is turned off and the rotation of the PTO shaft 14 is stopped.

Therefore, the power of the rotary tiller 84 is turned off, and the rotary tiller 84 is stopped. When the lifting switch 191 is further pushed to the second stage, the raising solenoid 136 is operated by the controller 100 as described above, and the rotary tiller 84 is raised.

When the elevating switch 191 is returned to the neutral position and the front side (lowering operation side) is pushed to the first stage, the controller 100 enters the PTO clutch pack 66 and rotationally drives the PTO shaft 14.

Therefore, the power of the rotary tiller 84 is turned on, and the rotary tiller 84 is activated. When the lifting switch 191 is further pushed to the second stage, the lowering solenoid 137 is operated by the controller 100 as described above, and the rotary tiller 84 is lowered.

Thus, the same effect as that of the lifting lever 130 can be obtained. Further, since the lifting switch 191 is in the vicinity of the cockpit 16, the lifting switch 191 can be operated while operating the work vehicle at the cockpit 16, and the operability is excellent.

FIG. 4 shows a power transmission system diagram of a tractor provided with the lifting lever 130 or the lifting switch 191 of this embodiment.
The engine 62 has a projecting engine shaft 1 on the rear side, and the engine shaft 1 is connected to the input shaft 2 of the clutch housing portion. The output shaft 3 and the PTO shaft 14 at the rear end are interlocked via a transmission mechanism in the mission case 65, and the front wheel output shaft 5 provided at the lower portion of the mission case 65 is interlocked. The output shaft 3 is supported along the front-rear direction at a substantially central portion of the rear portion in the mission case 65, has a drive pinion gear 53 at the rear end, meshes with the diff ring gear 46 of the rear differential 45, and a rear axle housing 75 (FIG. 1 (b)), the rear differential shaft 10 and the rear wheel shaft 11 that are mounted along the shaft are linked via a planetary reduction mechanism. The front wheel output shaft 5 is connected from the lower part of the transmission case 65 to the input shaft 26 of the front differential 47 provided at the center of the front axle housing 72 (FIG. 1B) through the lower part of the engine 62. It is configured to be linked to the front wheel shaft 13 via a front differential shaft 12 and a planetary speed reduction mechanism that are mounted along the axle housing 72. Note that gear drive shafts 15 and 17 for taking out power from the input shaft 2 to the hydraulic pump 80 (FIG. 5) are arranged in parallel with the input shaft 2.

The transmission meshing transmission shown in FIG. 4 has a PTO clutch pack 66 on a PTO countershaft 9 having a PTO shift counter gear 44 linked to an input gear 31 from an input shaft 2 driven by the engine shaft 1. Yes. The configuration of the PTO power transmission unit including the PTO clutch pack 66 and the input gear 31 is referred to as a PTO clutch E.

The input shaft 2 is provided with forward / reverse switching gears 42, 42 for forward / reverse switching in the idle state, and the reverse movement switching gear 42 on one reverse side has a back counter shaft 8 arranged in parallel with the input shaft 2. A back counter gear 43 provided on the main transmission shaft 19 is meshed, and the other forward-side forward / reverse switching gear 42 is provided with an input gear 48 fixed on the main transmission shaft 19 and an effective free rotation on the main transmission shaft 19. Four main transmission gears 33 having different diameters are provided. These four main transmission gears 33 are configured as a four-speed transmission, and are switched and shifted by the clutch pack 76. A transmission including the four main transmission gears 33 is referred to as a main transmission hydraulic clutch A.

Of the four main transmission gears 33 of the main transmission hydraulic clutch A, the main transmission gear 33 (for first speed) having the smallest effective diameter and the third main transmission having the smallest effective diameter are disposed on the main transmission shaft 19. A clutch pack 76 is fixed between the gear 33 (for the third speed) and the main transmission gear 33 (for the second speed) having the second smallest effective diameter and the main transmission gear 33 (for the second speed) having the largest effective diameter. The clutch pack 76 is fixedly provided between the 4th speed). Each of the two clutch packs 76 is provided with a friction clutch that connects each main transmission gear 33 so as to rotate integrally with the main transmission shaft 19.

Further, the input gear 48 that can mesh with the forward gear of the forward / reverse switching gear 42 meshes with the back counter gear 43 on the back counter shaft 8 together with the reverse gear of the forward / backward switching gear 42. The forward-side gear 42 and the reverse-side gear 42 of the forward / reverse switching gears 42 are alternatively integrated with the input shaft 2 by switching between the two forward / reverse switching clutch packs 60 composed of independent front and rear friction clutches. In this configuration, the vehicle can be switched between forward travel and reverse travel. A configuration including these gear 42, clutch pack 60, and the like including a hydraulic cylinder 85 (FIG. 5), which will be described later, is referred to as a forward / reverse hydraulic clutch D.

Further, a forward / reverse switching lever 115 (FIG. 1) for manually switching the forward / reverse hydraulic clutch D is provided at the post portion of the steering handle 73, and a clutch pedal 119 (FIG. 1) is provided under the foot of the handle post.

The sub-transmission shaft 20 provided coaxially with the main transmission shaft 19 is provided with two high and low-speed switching gears 34 having different effective diameters that are switched and shifted by the clutch pack 76. Furthermore, it can decelerate and can switch to high speed and low speed. The gear configuration capable of switching between high speed and low speed is referred to as a high / low shift clutch B.

Further, an output shaft 3 having three auxiliary transmission gears 35 having different effective diameters is arranged coaxially with the auxiliary transmission shaft 20. The output shaft 3 is configured to be shifted in three stages by the auxiliary transmission gear 35. The configuration of the gear 35 capable of three-speed shifting is referred to as an auxiliary transmission gear transmission mechanism C.

Further, a creep counter shaft 21 having a creep counter gear 49 that meshes with the auxiliary transmission gear 35 is provided in parallel with the output shaft 3. A travel counter shaft 6 having a main transmission counter gear 39 and a high / low speed switching gear 40 meshing with the main transmission gear 33 and the high / low speed switching gear 34 is disposed in parallel with the main transmission shaft 19 and the auxiliary transmission shaft 20. Rotation transmitted from the main transmission shaft 19 is changed by the main transmission gear 33, and the rotation is switched between the high and low speeds provided on the auxiliary transmission shaft 20 via the main transmission counter gear 39 and the high and low speed switching gear 40 in sequence. It is transmitted to the gear 34. The power transmitted to the high / low speed switching gear 34 is transmitted to the output shaft 3 through the clutch pack 76 and through the transmission mechanism by the auxiliary transmission gear 35 provided on the auxiliary transmission shaft 20.
This traveling power transmission system is provided with a forward / reverse rotation PTO which is a transmission mode for rotating the PTO interlocking shaft 4 provided with a PTO forward / reverse switching gear 37 mechanism.

A front wheel interlocking gear 51 that has a front wheel interlocking gear 51 that rotatably supports the subtransmission countershaft 27 of the subtransmission countergear 38 that meshes with the subtransmission gear 35 and that is interlocked from the output shaft 3 via the front wheel take-out gear 36. A shaft 28 is provided, and a PTO reduction shaft 23 having a PTO reduction gear 50 is provided on the front extension axis of the front wheel interlocking shaft 28. Further, a PTO interlocking shaft 4 is provided at a position parallel to the front wheel interlocking shaft 28, and the PTO forward / reverse switching gear 37 for switching the PTO interlocking shaft 4 between forward rotation and reverse rotation at the front end on the same axis as the PTO interlocking shaft 4. The switching shaft 22 and the PTO transmission shaft 18 of the PTO transmission gear 32 are arranged.

A PTO reverse rotation counter shaft 24 having a PTO reverse rotation counter gear 52 that meshes with the PTO normal / reverse switching gear 37 is provided on the side of the PTO forward / reverse switching shaft 22, and the input shaft is inserted by the insertion of the PTO clutch pack 66. Power is transmitted from 2 to the PTO forward / reverse switching shaft 22 via the PTO transmission gear 32, the PTO transmission counter gear 44, the PTO forward / reverse switching gear 37, and the like. The forward / reverse switching gear 37 uses a clutch ring having the same form as the PTO transmission gear 32. A reverse rotation counter shaft 24 having a PTO reverse rotation counter gear 52 is provided on the side of the PTO normal / reverse switching shaft 22, and the PTO reverse rotation counter gear 52 receives the interlocking from the PTO reduction gear 50 and performs PTO forward / reverse switching. The gear 37 can be reversely rotated. A deceleration shaft 23 is disposed behind the PTO counter shaft 9.

Further, the front wheel output shaft 5 arranged at the lower stage in the transmission case 65 is mounted on the bottom of the rear portion of the transmission case 65, and the input shaft 26 of the front differential 47 through the front wheel interlocking shaft 25, the coupling and the like. Connect to A front wheel drive shaft 7 is disposed on the side of the front wheel output shaft 5. A front wheel gear 55 is provided at the rear end of the front wheel drive shaft 7. Further, the first front wheel interlocking gear 51 on the front wheel interlocking shaft 28 meshes with the front wheel take-out gear 36 at the rear end portion of the output shaft 3 and is transmitted to the front wheel interlocking shaft 28 via the first front wheel interlocking gear 51. The driving force of the output shaft 3 is transmitted to the second front wheel interlocking gear 54 that rotates integrally with the front wheel interlocking shaft 28, and is transmitted from the front wheel interlocking gear 54 to the front wheel driving shaft 7.

A front wheel drive clutch pack 67 is provided on the front wheel drive shaft 7, and geared from the front end of the drive shaft 7 to the front wheel output shaft 5. Further, two front wheel drive switching gears 41 having different effective diameters are arranged on the left and right sides of the front wheel drive clutch pack 67, and the two front wheel drive switching gears 41 are provided with two effective wheel diameters provided on the counter shaft 59. The front wheel drive shaft 7 can be driven at either one of the two reduction ratios by meshing with the drive counter gear 56 and selectively connecting the front wheel drive clutch pack 67.

When the front wheel drive clutch pack 67 is shifted to the neutral position, the front wheel 61 is not driven, and a rear wheel drive two-wheel drive mode is adopted. When the front wheel drive clutch pack 67 is switched to the low speed position by hydraulic operation, the front wheel 61 is moved to the rear. A four-wheel drive configuration in which the wheel 63 is driven at a constant speed of about one time with respect to the wheel 63 is used, and when the front wheel drive clutch pack 67 is switched by hydraulic operation to shift to a high speed position, the front wheel 61 is moved to the rear wheel 63 by about 2 It is possible to travel by adopting a four-wheel drive mode in which the driving speed is doubled.

With the meshing transmission having the above-described configuration, the rotational power of the engine 62 is composed of a main transmission hydraulic clutch A having four speeds and a second speed through a forward / reverse hydraulic clutch D constituting the main clutch. The high and low speed transmission clutch B and the auxiliary transmission gear transmission mechanism C composed of three speeds are used to change the speed to any one of the total 24 speeds, and the resulting rotational power passes through the rear differential 45 and the rear wheels 63 Driven. Further, the rotational power changed by the auxiliary transmission gear transmission mechanism C is also transmitted to a front wheel drive clutch pack (two-wheel drive / four-wheel drive switching clutch) 67, which causes the front wheels 61 to be “constant speed” or “acceleration”. , The front wheel 61 is driven via the front differential 47.

Further, the PTO transmission gear 32, the traveling main transmission gear 33, the high / low speed switching gear 34, the auxiliary transmission gear 35, and the like are arranged along the axis of the output shaft 3 having the drive pinion gear 53. The transmission of the traveling system is interlocked with the drive pinion gear 53 via the main transmission gear 33, the high / low speed switching gear 34, the multiple transmission gear 35, etc. arranged on the axis of the output shaft 3 from the input shaft 2. Further, the PTO shift is linked via a PTO transmission gear 32 provided at the front end portion on the axis of the output shaft 3.

Next, FIG. 5 shows a hydraulic circuit diagram of a tractor provided with the lifting lever 130 or the lifting switch 191 of this embodiment.
In the hydraulic circuit diagram of FIG. 5, the left and right brake cylinders 83 that brake the left and right rear wheels 63 independently, the four-wheel drive clutch cylinder 99 that switches the power transmitted to the front wheels 61 to “constant speed” or “acceleration”, steering A power steering device 103, a PTO clutch cylinder 104, a PTO clutch switching valve 150, a PTO clutch proportional pressure control valve 106, and the like that are operated by rotating the handle 73 are provided. In addition, the circuit 101 of the dashed-dotted line portion is a main hydraulic circuit (working machine lifting / lowering, horizontal working machine extraction, external hydraulic pressure taking out, etc.) and has little relation to sub-circuits (running / brake / diff lock / PTO side circuit). Is omitted.

The hydraulic oil discharged from the hydraulic pump 80 is connected to a hydraulic clutch cylinder 87 that operates the gears 33 for the fourth speed and the second speed of the main transmission hydraulic clutch A via the clutch pack 76 via the pressure reducing valve 81a. Hydraulic clutch cylinder that is supplied to a main transmission (2-4) clutch proportional pressure control valve 89 for switching the hydraulic clutch cylinder 88 and further operates the first and third gears 33 of the main transmission hydraulic clutch A, respectively. 91 and the hydraulic clutch cylinder 92 are supplied to a main transmission (1-3) clutch proportional pressure control valve 93 that switches.

The hydraulic fluid that passes through the pressure reducing valve 81 a is supplied to the switching valve 86 that switches between the forward and backward hydraulic clutch D of the forward / reverse clutch cylinder 85 via the on / off control valve 129 of the forward / reverse clutch cylinder 85. The forward clutch pressure sensor 110 (FIG. 7) and the reverse clutch pressure sensor 111 (FIG. 7) detect whether the hydraulic oil is supplied to the forward hydraulic clutch D or the reverse hydraulic clutch D of the forward / reverse clutch cylinder 85. it can.

Similarly, the hydraulic oil supplied to the hydraulic clutch cylinders described above and below is a pressure sensor (for example, for the first to fourth speeds of the hydraulic clutch A) provided in the oil path on the inlet side to each hydraulic clutch cylinder. The pressure sensors 145a to 145d, the pressure sensor 146 of the PTO clutch E, etc. (FIG. 7)) can be detected.

The hydraulic oil discharged from the hydraulic pump 80 is branched and supplied to the left and right brake cylinders 83 via the pressure reducing valve 81b and the brake valve 82a. The brake valve 82a is a switching control valve that selects the rear wheel 63, and the brake valve 82a is integrated with a pressure control valve 82b that adjusts the braking force.

Further, the hydraulic oil passing through the pressure reducing valve 81b is transmitted to the clutch pack 76 at one of the two gears 40 of “high speed” and “low speed”. Is supplied to the control valves 96a and 96b for switching the high / low hydraulic clutch cylinder 95 to be operated.

Further, the hydraulic oil passing through the pressure reducing valve 81 b is branched into the front-wheel differential lock cylinder 98 a for the front differential 47 and the rear-difference lock cylinder 98 b for the rear differential 45 through the differential lock control valve 97.

Further, hydraulic oil 99 for switching the gear 41 of the front wheel drive clutch pack 67 is supplied with hydraulic oil via the pressure reducing valve 81b via the switching control valve 94.

Similarly, the hydraulic oil passing through the pressure reducing valve 81b is supplied to the PTO clutch cylinder 104 via the PTO valves 105 and 106, and the pressure of the PTO clutch E is adjusted.
Further, the hydraulic pressure from the hydraulic pump 80 shown in FIG. 5 is configured to supply hydraulic oil to the orbit roll 107 that is operated by operating the power steering handle 73.

FIG. 6 shows a cross-sectional configuration diagram of a forward / reverse clutch cylinder 85 that switches the forward / reverse gears 42, 42.
Forward / reverse switching comprising a pair of front and rear cylinders 85F and 85R, pistons 78F and 78R that are operated by hydraulic oil (oil) flowing in, and a plurality of sets of friction plates that are in contact with each other by the operation of the pistons 78F and 78R. Clutch packs 60 and 60 are provided, respectively.

When the clutch pedal 119 is not operated (when the foot pedal 119 is not depressed), the oil flows into one of the forward and reverse cylinders 85F and 85R, and the piston 78F or 78R is in an activated state. Yes, the forward / reverse switching clutch packs 60, 60 are connected, and the engine power is transmitted to the forward drive mechanism or the reverse drive mechanism in the transmission 24. In addition, return springs (compression springs) 77F and 77R are provided in the cylinders 85F and 85R, and the return springs 77F and 77R are urged toward the side where the forward and reverse clutch packs 60 and 60 are disconnected. Is done. Therefore, when the clutch pedal 119 is operated (when the foot pedal 119 is depressed), the oil in the cylinder 85F or 85R flows out, and the piston 78F or 78R moves in the return direction by the urging force of the return spring 77F or 77R. The connected state of the forward or reverse clutch pack 60 is released.

In the forward / reverse switching clutch pack 60 configured as described above, the oil in the piston 78F or 78R applies thrust to the piston 78F or 78R by centrifugal force generated by the rotation of the input shaft 2 that is the clutch input shaft. As a result, a power transmission torque is generated by a force obtained by adding a thrust by a centrifugal force to the torque of the input shaft 2 generated by the hydraulic pressing pressure.

The centrifugal force can be obtained by the following equation.
First, the pressure P in the radial direction of the input shaft 2 when the oil in the clutch cylinder 85F or 85R rotates completely integrally with the forward clutch pack 60 or the reverse clutch pack 60 is expressed by the following equation: (Forced vortex equation) The distribution of the pressure P in the radial direction of the input shaft 2 is as shown in FIG. 6, and the value of the pressure P increases toward the outer side in the radial direction.

P = P0 + 1 / 2ρr2ω2 (1)
Here, P0: axial pressure (Pa), ρ: density (kg / m 3), r: distance from the axial center (m), ω: clutch angular velocity (rad / s).

Therefore, the thrust of the piston 78F or 78R can be obtained by the following equations (2) and (3) by dividing the equation (1) in the radial direction.
(Equation 1)
(Equation 2)
Where F: piston thrust (N), A: piston area (m2), φ1: piston inner diameter (m),
φ2: Piston outer diameter (m).

The first term of the expression (3) is the thrust of the piston 78F or 78R by the control pressure of the hydraulic valve 86 operated by the solenoid 86F (forward) or 86R (reverse), and the second term is the oil in the cylinder 85F or 85R. Represents thrust due to centrifugal force.

From equation (3), even if the pressure by the hydraulic valve 86 is zero, if the forward clutch pack 60 or the reverse clutch pack 60 is rotating, thrust is generated, and therefore the return spring 77F or The set load of 77R must be larger than the thrust by centrifugal force. Although this thrust cannot be measured by the pressure sensor, it is determined by the rotational speed of the input shaft 2 and is therefore estimated from the engine rotational speed (detected by the engine rotational speed sensor 112 shown in FIG. 7) and controlled accordingly. It becomes possible.
The above formulas (1) to (3) are applicable not only to the forward / reverse clutch D but also to other hydraulic clutches A, B, and E.

Then, as shown in FIG. 4, a torque sensor 142 is provided on the power transmission shaft from the engine 62 between the PTO counter shaft 9 and the PTO shaft 14, and the shaft torque generated during the connection control of the PTO clutch E is confirmed. The connection pressure of the PTO clutch E may be controlled. The connection pressure of the PTO clutch E can be detected from the pressure sensor 146 (FIG. 7). The torque sensor 142 may be provided at any position as long as it is a power transmission shaft between the lower shaft of the PTO clutch pack 66 and the PTO shaft 14, that is, the shaft after the power passes through the PTO clutch pack 66. A PTO clutch output shaft torque sensor 142 may be provided on the PTO clutch output shaft (for example, the PTO forward / reverse switching shaft 22). Further, as shown in FIG. 4, an output shaft torque sensor 151 may be provided on the main transmission shaft 19.

When the PTO clutch output shaft torque sensor 142 is provided on the PTO clutch output shaft, the shaft torque generated by the rotation of the PTO clutch output shaft gives an angular acceleration to the PTO shaft 14 to which power is transmitted. The angular acceleration varies depending on the magnitude of the shaft torque. That is, when the shaft torque increases at a stretch, a steep angular velocity is given to the PTO shaft 14 and the rotation speed of the work machine such as the rotary tiller 84 changes rapidly. Therefore, the work machine does not rotate gradually, and an abrupt load is applied to the work machine side, which is not preferable.

When the engine speed is determined, the speed and transmission torque of the PTO shaft 14 are determined from the reduction ratio in the mission 65. However, since the transmission torque is added due to the centrifugal force as in the above formula, the pressure correction of the PTO clutch pack 66 (to be fixed at the design value) obtained from the actual reduction ratio of the mission 65 (fixed at the design value) Pressure control).

By adopting this configuration as described above, the torque of the power transmission shaft from the engine 62 is detected and the pressure of the PTO clutch pack 66 is controlled, so that a rotational force can be smoothly applied to a work machine such as the rotary tiller 84. The power connection from the engine 62 to the working machine such as the rotary tiller 84 can be made smooth.

FIG. 7 shows a torque control block diagram in the case where the torque sensor 142 is provided on the power transmission shaft of the tractor shown in FIG. 1, and FIG. 8 shows between the lower shaft of the PTO clutch pack 66 and the PTO shaft 14. 6 shows a flow of torque control by the controller 100 when a PTO clutch output shaft torque sensor 142 is provided.

When clutch torque control is started in a standby state in which the engine 62 is rotating, the controller 100 reads the sensors and switches shown in FIG. In step A, when the PTO clutch E enters the full pressure connection state, the connection pressure of the PTO clutch E based on the sensor value from the pressure sensor 146 is compared with the output shaft torque sensor value of the PTO clutch output shaft torque sensor 142. A control valve drive current value for operating the PTO clutch proportional pressure control valve 106 according to the generated pressure and the generated torque is stored in the memory 102.

If the PTO clutch E is boosted in step B, the process proceeds to step C, and it is confirmed whether or not the sensor value is detected by the PTO shaft rotation sensor 165 when the PTO clutch E is boosted.

In Step C, if the power transmission shaft is detected by the torque sensor 142, the current for operating the PTO clutch proportional pressure control valve 106 is suddenly decreased so that the generated shaft torque is less than the specified torque (PTO). In order to operate the PTO clutch proportional pressure control valve 106 so that the generated torque matches the specified line after the specified time (about several seconds) has elapsed in step I), the connection pressure of the clutch E is equivalent to zero or the switching valve 105 is turned off. To control the current.

In step H, the rotation speed calculated from the reduction ratio (the shaft rotation speed of the PTO clutch / the rotation speed of the engine 62) in which the generated torque matches the specified line and the rotation speed of the PTO shaft 14 corresponds to the specified torque line; When the values almost coincide, the boosting of the PTO clutch E is completed, the full pressure connection output is performed (the controlled current value is continuously output), and the flow is returned. The engine speed of the engine 62 is detected by the engine speed sensor 112.

If the PTO clutch output shaft torque sensor 142 does not detect in step C, the process proceeds to step D, where the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14 or the like on the lower side of the PTO clutch pack 66). If torque is generated at any rotational speed (changes in the rotational speed (torque) may be detected), the flow is the same as when the output shaft torque sensor 142 detects in step C above. .

On the other hand, in step D, if no shaft torque is generated on the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14), the initial piston movement output of the PTO clutch cylinder 104 (FIG. 5) is set to the specified stroke. Implement and activate the PTO clutch E.

In step E, if the specified initial output is not completed, the process returns to step C. If completed, the process proceeds to step F. In step F, if there is no detection by the PTO shaft rotation sensor 165, the process proceeds to step G and the torque of the PTO clutch output shaft (for example, the lower shaft of the PTO clutch pack 66 such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14). Check for occurrence of. If no torque is generated, a slightly higher pressure equivalent current is supplied to operate the PTO clutch proportional pressure control valve 106 and the process returns to step F.

In step F and step G, if there is detection by the PTO shaft rotation sensor 165 or if shaft torque of the PTO clutch output shaft is generated, the PTO clutch proportional pressure control valve is adjusted so that the generated torque matches the specified line. Control the current for actuating 106 and proceed to step H.

Further, if the PTO clutch E is not in the full pressure connection state in step A, the process proceeds to step B. If the pressure of the PTO clutch E is not increased in step B, control of other clutches (forward / reverse hydraulic clutch D (forward hydraulic clutch, reverse drive) is performed. After performing the flow shown in FIG. 11 for the hydraulic clutch), the main transmission hydraulic clutch A, the high / low transmission clutch B, etc., the flow of FIG. 8 is returned.

As shown in FIG. 7, the PTO clutch E is configured to control the connection pressure by the PTO clutch proportional pressure control valve 106. Then, a predetermined shaft torque change line is provided during the pressure increase of the PTO clutch E shown in step B of FIG. 8, and the connection pressure of the PTO clutch E is controlled so as to coincide with the shaft torque change line. By adopting this configuration, excessive torque is not suddenly applied to the PTO clutch output shaft (PTO forward / reverse switching shaft 22, PTO shaft 14, etc.).

FIG. 9 shows setting lines for each of the torque controls in FIGS. 7 and 8 (the same control is performed for a plurality of multi-plate clutches A, B, D, and E, but the clutch E will be described here). An example in which the clutch pressure is adjusted so as not to exceed the torque is shown.

In FIG. 9, the horizontal axis represents time, and the vertical axis represents PTO shaft torque. Further, “a” in FIG. 9 is an initial pressure (depending on the capacity of the clutch), and “b” is a specified torque after calculation. This “b” is a value after subtracting the influence of the centrifugal force of the clutch, and varies depending on the rotational speed of the shaft on the upper side of the PTO clutch E. “Tx” is the time from when a current starts to flow through the solenoid of the PTO clutch proportional pressure control valve 106 until the hydraulic pressure reaches a constant pressure state (depending on the clutch). FIG. 9 shows that the torque is raised over 1.5 seconds in order to obtain the specified torque value b.

Since the influence of the centrifugal force of the clutch E can be predicted when the upper rotation of the PTO clutch E is known, an example of starting the PTO clutch E from the beginning by this prediction is shown.

If the torque generated on the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14) exceeds the torque change line (FIG. 9) of the predetermined shaft during the pressure increase of the PTO clutch E, the controller 100 Thus, after the connection pressure of the PTO clutch E is greatly reduced, control for gradually increasing the pressure may be performed.

For example, when the sensor value is detected by the PTO clutch output shaft torque sensor 142 in Step C of FIG. 8, the PTO clutch proportional pressure control is performed so that the generated torque is equal to or less than a specified torque (predetermined shaft torque change line). After the current for operating the valve 106 is suddenly decreased, the current is gradually increased so that the generated torque matches the specified line, and the connection pressure of the PTO clutch E is controlled.

Even when a change in shaft torque generated on the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14) during the PTO clutch pressure increase suddenly increases, the controller 100 causes the PTO clutch proportional pressure control valve 106 to operate. It is preferable that the driving current is once sharply decreased and then increased.

If the connection pressure is not controlled by the PTO clutch proportional pressure control valve 106 (such as when the piston of the PTO clutch cylinder 104 is moving) and the clutch meet of the PTO clutch E is reached, the meet (connection) timing may be incorrect. The shaft torque generated at the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14) at the meet point of the PTO clutch E may change suddenly.

However, the current for operating the PTO clutch proportional pressure control valve 106 by the controller 100 in accordance with the change of the shaft torque generated in the PTO clutch output shaft (PTO forward / reverse switching shaft 22 or PTO shaft 14) in this way. Since it decreases rapidly once, the load given to the rotary tiller 84 can be reduced.

Also, when the PTO clutch proportional pressure control valve 106 is actuated to start the pressure increase of the PTO clutch E, and the shaft torque generated on the PTO clutch output shaft (such as the PTO forward / reverse switching shaft 22 or the PTO shaft 14) is the specified torque. First, the PTO clutch proportional pressure control valve 106 (FIG. 5), which is a hydraulic valve of the PTO clutch E, is operated to control the connection pressure of the PTO clutch E to near zero, or the PTO clutch proportional pressure control valve (switching valve). 105 may be turned off, and then the connection pressure of the PTO clutch E may be increased.

If the change point of the connection pressure of the PTO clutch E is regarded as the meet point of the PTO clutch and the pressure increase of the connection pressure of the PTO clutch E is started, smooth PTO connection can be performed.

Then, the PTO clutch output shaft torque sensor 142 is provided on the PTO clutch output shaft (PTO forward / reverse switching shaft 22, PTO interlocking shaft 4, or PTO shaft 14, etc., so long as it is on the lower side of the PTO clutch), step H in FIG. As shown in FIG. 5, when the rotational speed of the PTO clutch output shaft approaches the rotational speed calculated from the reduction ratio (PTO clutch shaft rotational speed / engine rotational speed) corresponding to the specified torque line, the PTO clutch output shaft is generated. Control of the connection pressure of the PTO clutch E in accordance with the shaft torque is stopped, and the current for operating the PTO clutch proportional pressure control valve 106 by the controller 100 is preferably controlled as a current value corresponding to the maximum pressure. That is, even when the connection pressure of the PTO clutch E is being increased, the controlled current value is continued by stopping the increase. FIG. 10 is an explanatory diagram of this configuration.

The target torque (broken line) is obtained from the engine speed and the reduction ratio, and the current I for operating the PTO clutch proportional pressure control valve 106 is set so that the shaft torque T generated on the PTO clutch output shaft becomes the target torque To. A target current value Io corresponding to the maximum pressure is set, and the shaft torque is controlled so that the output of the shaft torque T is about 5% less than the target torque To.

When the rotation of the PTO clutch output shaft (PTO forward / reverse switching shaft 22, PTO interlocking shaft 4, or PTO shaft 14, etc.) starts and the inertial force by the rotary tiller 84 is applied to the PTO clutch output shaft, The shaft torque T generated on the clutch output shaft may decrease. Even if the rotation speed of the PTO clutch output shaft reaches the set rotation speed, the connection pressure of the PTO clutch E may decrease when the control by the controller 100 is continued.

In such a case, the PTO clutch E slips, and the rotary tiller 84 does not rotate properly and cannot be tilled. Therefore, the fact that the rotation of the output shaft of the PTO clutch has reached the set rotational speed means that the time to be controlled by increasing the connection pressure of the PTO clutch E has ended, and the set pressure is maintained as it is. It is only necessary to connect the PTO clutch E (controlling the pressure of the current value Io in FIG. 10 as the set pressure).

FIG. 11 shows a flow of torque control by the controller 100 when the output shaft torque sensor 151 is provided on the main transmission shaft 19 which is the output side of the forward / reverse switching clutch packs 60, 60. In addition, when providing an output shaft torque sensor in other clutches (hydraulic clutches A and B), any shafts after passing the clutch pack 76 such as a torque sensor 153 (FIG. 4) may be used. Further, the reverse clutch output shaft torque sensor 152 may be provided on the back counter shaft 8.

When the controller 100 receives the sensor signal of the torque sensor 151 in the standby state in which the engine 62 is rotating, the clutch torque control starts. The controller 100 reads the sensors and switches shown in FIG. 7, and when the forward clutch pack 60 is in full pressure connection in step J, the connection pressure of the forward clutch pack 60 based on the sensor value from the pressure sensor 110 and the output shaft. Control valve drive current value for operating solenoids 86F and 86R of forward / reverse clutch proportional pressure control valve (switching valve) 86 in accordance with the generated pressure and the generated torque by comparing the output shaft torque sensor value of torque sensor 151 with memory 102. The solenoids 86F and 86R are operated by the sensor value of the forward / reverse switching lever position sensor 167 (FIG. 7) that detects the operation position of the forward / reverse switching lever 115.

In step K, the forward / reverse switching lever 115 is operated, and when the forward / reverse clutch packs 60, 60 are stepped up to the forward side, the process proceeds to step L to check whether the sensor value is detected by the vehicle speed sensor 170 (FIG. 7). .

In step L, when the sensor value is detected by the vehicle speed sensor 170, the current for operating the forward / reverse clutch switching solenoids 86F and 86R is suddenly decreased so that the shaft torque generated in the main transmission shaft 19 is equal to or less than the specified torque. (When the connection pressure of the forward / reverse clutch D is equivalent to zero or the forward / reverse clutch proportional pressure control valve (switching valve) 86 is turned off), the process proceeds to step R and occurs when a specified time (for example, 1.0 second or less) elapses. The current for operating the forward / reverse clutch switching solenoids 86F and 86R is controlled so that the torque matches the specified line.

In step Q, the generated torque matches the specified line, and the rotational speeds of the front and rear wheel shafts are calculated from the reduction ratio (the rotational speed of the main transmission shaft 19 / the rotational speed of the engine 62) corresponding to the specified torque line. When the rotational speed is almost the same, complete the pressure increase of the forward / reverse clutch packs 60, 60 and execute the full pressure connection output (hold the current value of the total pressure at the time when the rotational speed is almost the same, ), Return the flow.

If the sensor value is not detected by the vehicle speed sensor 170 in step L, the process proceeds to step M. If the torque of the main transmission shaft 19 is generated, the sensor value is detected by the vehicle speed sensor 170 in the previous step L. The flow is the same as when there is.

On the other hand, if no shaft torque is generated in the main transmission shaft 19 in step M, the initial piston movement output (initial pressure) of the piston 78F of the forward clutch cylinder 85F is executed for the specified stroke. This is because when the hydraulic multi-plate clutch is operated, it is necessary to raise the initial pressure (total pressure) once to stabilize the oil amount of the clutch.

In step N, if the specified initial output is not completed, the process returns to step L. If completed, the process proceeds to step O. When the sensor value is not detected by the vehicle speed sensor 170 in step O, the process proceeds to step P, and it is confirmed whether or not the torque of the main transmission shaft 19 is generated. If no torque is generated, a slightly higher pressure-corresponding current is supplied to operate the solenoids 86F, 86R of the forward / reverse clutch proportional pressure control valve 86, and the process returns to step O.

Further, in step O and step P, when the sensor value is detected by the vehicle speed sensor 170 or when the shaft torque of the main transmission shaft 19 is generated, the forward / reverse clutch proportional pressure is set so that the generated torque matches the specified line. The current for operating the solenoids 86F and 86R of the control valve (switching valve) 86 is controlled, and the process proceeds to Step Q.

Further, if the forward clutch pack 60 is not in the full pressure connection state in step J, the process proceeds to step K. If the forward clutch pack 60 is not boosted in step K, control of other clutches (reverse clutch pack 60, main transmission hydraulic pressure) is performed. The flow shown in FIG. 11 for the clutch A, the high / low shift clutch B, etc.) is performed, and the flow is returned.

Next, an example in which the output shaft torque sensor 153 (FIG. 4) is provided on the output shaft 3 after passing through the clutch pack 76 will be described.
An output shaft torque sensor 153 is provided on the power transmission shaft from the clutch output shafts of the hydraulic clutches A, B, and D of the power transmission unit of the traveling system to the wheel (front wheel 61, rear wheel 63). While checking the generated shaft torque, control the connection pressure of the hydraulic clutch. The connection pressure of the hydraulic clutch can be detected from the pressure sensors 145a to 145d.

Conventionally, the rotational speed of each clutch output shaft of the hydraulic clutches A, B, and D is detected to control the connection pressure of each clutch A, B, and D.
However, the shaft torque generated in each clutch output shaft of the hydraulic clutches A, B, and D gives an angular acceleration to the output shaft, and this angular acceleration differs depending on the magnitude of the shaft torque. Here, when the shaft torque increases at a stretch, a sudden acceleration is given to the tractor, and a start shock or a shift shock due to a sudden change of the vehicle speed and a sudden start of the tractor occurs. However, by directly detecting the shaft torque generated in the clutch output shafts of the hydraulic clutches A, B, and D, it is possible to perform control with good responsiveness by directly detecting and controlling the so-called shaft torque.

In the control of the main transmission hydraulic clutch A, the current for operating the main transmission (1-3) clutch proportional pressure control valve 93 and the main transmission (2-4) clutch proportional pressure control valve 89 is controlled. When the current is suddenly decreased, the main transmission (1-3) solenoid switching valve 168 and the main transmission (2-4) solenoid switching valve 169 may be turned off.

As shown in FIG. 7, the hydraulic clutches A, B, and D have proportional pressure control valves (main transmission (2-4) clutch proportional pressure control valve 89, main transmission (1-3) clutch proportional pressure control valve 93, The pressure is controlled by a control valve 96, a pressure control valve 82b, a forward / reverse clutch proportional pressure control valve (switching valve) 86, a diff lock control valve 97, etc.), and a predetermined pressure during pressure increase of the hydraulic clutch shown in step K of FIG. An axial torque change line is provided, and the connection pressures of the clutch hydraulic clutches A, B, and D are controlled so as to coincide with the axial torque change line. By adopting this configuration, excessive torque is not suddenly applied to the clutch output shafts of the hydraulic clutches A, B, and D.

FIG. 12 shows a reduction ratio (torque ratio) in the combination of the main transmission hydraulic clutch A, the high / low transmission clutch B, and the auxiliary transmission gear transmission mechanism C in which the torque control in FIGS. ) Shows an example in which the clutch pressure is adjusted and connected so as not to exceed the travel axis setting line torque. Note that the control line is basically the same as the control example shown in FIG. 9A only by changing the PTO axis shown in FIG. 9A to the travel axis.

In FIG. 12, the horizontal axis indicates time, and the vertical axis indicates generated torque. Further, four traveling shaft torques in FIG. 12 are described because of the influence of the centrifugal force of each of the hydraulic clutches A, B, and D depending on the shift position from the first speed to the eighth speed according to the output of the transmission. This is the specified torque after subtracting. FIG. 12 shows that the torque is raised over 2.0 seconds to obtain the specified torque value.

Since the influence of the centrifugal force of the clutch torque can be predicted when the rotational speed of the hydraulic clutch on the upper side of each hydraulic clutch A, B, D is known, an example of starting the corresponding hydraulic clutch from the beginning by this prediction is shown. ing.
Since the reduction ratio of the torque differs depending on the combination of the main transmission hydraulic clutch A, the high / low transmission clutch B, the auxiliary transmission gear transmission mechanism C, etc., adjustment is made so that the prescribed line torque is obtained at any gear shift position. The torque lines set according to the shift positions such as the first speed and the second speed are different, and the lower the torque line is, the lower the torque ratio is (the lower the traveling speed is).

When the torque generated on the clutch output shafts of the hydraulic clutches A, B, and D exceeds the shaft torque change line (FIG. 12) during the pressure increase of the hydraulic clutches A, B, and D, the controller 100 controls the hydraulic clutch A. It is preferable to perform control to gradually increase the pressure after the connection pressure of B, D is greatly reduced once.

For example, in step L of FIG. 11, when the sensor value is detected by the vehicle speed sensor 170, the proportional pressure control valves (main shift (2) of the hydraulic clutches A, B, and D are set so that the generated torque is not more than a specified torque. -4) Clutch proportional pressure control valve 89, main speed change (1-3) clutch proportional pressure control valve 93, control valve 96, pressure control valve 82b, diff lock control valve 97, etc.) From this, the connection pressure is controlled by gradually increasing the current so that the generated torque matches the specified line.

By controlling the connection pressure of the hydraulic clutches A, B, and D so as not to give a sudden torque change to the tractor, an appropriate acceleration can be given without steep acceleration given to the tractor under various conditions. it can.

Even when the change in the shaft torque generated in the clutch output shaft during the pressure increase of the hydraulic clutches A, B, and D suddenly increases, the controller 100 causes the forward / reverse clutch proportional pressure control valve 86, the main speed change (1-3). ) Controlling the clutch proportional pressure control valve 93, the main transmission (2-4) clutch proportional pressure control valve 89, or the high / low clutch switching valve (control valves 96a, 96b), the drive current was once decreased suddenly. It is better to raise it later.

Clutch proportional pressure control valve (forward / reverse clutch proportional pressure control valve 86, main transmission (1-3) clutch proportional pressure control valve 93, main transmission (2-4) clutch proportional pressure control valve 89, control valves 96a, 96b, etc.) In the process from when the connection pressure is not controlled by (for example, when the clutch pistons 78F, 78R, etc. of the forward / reverse clutch cylinder 85 are moving) to the clutch meet of the hydraulic clutches A, B, D, If the timing is incorrect, the shaft torque generated on the traveling shaft such as the main transmission shaft 19 and the sub transmission shaft 20 may suddenly change at the meet points of the hydraulic clutches A, B, and D. However, the controller 100 operates the clutch proportional pressure control valves 86, 93, 89, 96 a, 96 b, etc. according to changes in the shaft torque generated on the travel shafts such as the main transmission shaft 19 and the auxiliary transmission shaft 20 in this way. Therefore, the load applied to the rotary tiller 84 can be reduced.

Further, after the clutch proportional pressure control valves 86, 93, 89, 96 a, 96 b, etc. are actuated (after the pressurization of the hydraulic clutches A, B, D) is started, they are generated on traveling shafts such as the main transmission shaft 19 and the auxiliary transmission shaft 20. When the shaft torque is a specified torque, the proportional pressure control valves 86, 93, 89, 96a, and 96b of the hydraulic clutches A, B, and D are once operated to reduce the connection pressure of the hydraulic clutches A, B, and D to 0. Alternatively, the clutch proportional pressure control valves 86, 93, 89, 96a, 96b, etc. may be turned off, and then the connection pressures of the hydraulic clutches A, B, D may be increased.

If the change point of the connection pressure of the hydraulic clutches A, B, and D is regarded as the meet point of the hydraulic clutches A, B, and D, and the pressure increase of the connection pressure of the hydraulic clutches A, B, and D is started, smooth running Shifting can be performed.

When the vehicle speed sensor 170 is provided and the rotational speed of the front wheel shaft 13 or the rear wheel shaft 11 approaches the rotational speed calculated from the reduction ratio (axle rotational speed / engine rotational speed) corresponding to the specified torque line, the main transmission shaft The control of the connection pressures of the hydraulic clutches A, B, D according to the shaft torque generated on the traveling shaft such as 19 and the auxiliary transmission shaft 20 is stopped, and the clutch proportional pressure control valves 86, 93, 89, 96a are controlled by the controller 100. , 96b may be controlled to a current corresponding to the maximum pressure. That is, the pressure increase is stopped even while the connection pressure of the hydraulic clutches A, B, and D is being increased. This configuration is the same as the control example shown in FIG. 10 except that the PTO clutch E in FIG. 10 is changed to hydraulic clutches A, B, and D, which are traveling clutches.

When the tractor starts to move, an inertial force is applied to the tractor, and the shaft torque of the traveling shaft such as the main transmission shaft 19 and the auxiliary transmission shaft 20 may decrease. In addition, when working with the rotary tiller 84 and the like, the rotary tiller 84 rotates in the soil and thrust is generated, causing a dashing phenomenon (the machine suddenly starts when trying to plow a hard field). is there. In such a case, by applying the torque of the engine 62 to the traveling shafts such as the main transmission shaft 19 and the auxiliary transmission shaft 20 as they are, sudden start can be prevented and dashing can be eliminated.

13 is a top view of the vicinity of the cockpit of the tractor of FIG. 1, FIG. 14 is a perspective view of the same, and FIG. 15A is a plan view of the switch box 180 shown in FIGS. FIG. 15 (b) shows a side view of FIG. 15 (a). 13 to 15, members around the steering handle 73 shown in FIGS. 2 and 3 are omitted.

On the left side of the pilot seat 16 of the tractor, the forward / reverse switching lever 115 for switching the tractor forward and backward, the parking brake 172, and the PTO change lever 173a on the front side can be changed to 2nd speed-N (neutral) -1 speed. ), The rear PTO change lever 173b and the like are arranged. There are three types of PTO change levers 173b on the rear side depending on the model (the same figure is shown except that the functions are different).

The Z type is a forward / reverse switching lever (forward rotation on the front side and reverse rotation on the rear side), and the WX type is an economy PTO switching lever (front side is off-rear side is on). . The GWD type is a ground PTO switching lever (the front side is turned off and the rear side is turned on). When turned on, the rotation of the PTO shaft is synchronized (synchronized) with the vehicle speed.

On the other hand, on the right side of the tractor's cockpit 16, there are an accelerator pedal 175, a throttle lever 176 (increase the engine speed when it is tilted forward, and idling when it is at the front), an engine speed memory switch 177a and the like. The engine speed storage switch 177a is a so-called seesaw switch and automatically returns to neutral when the finger is released. Further, the controller 100 can store two kinds of engine speeds, and is therefore a changeover switch. For example, when the upper side of the engine speed storage switch 177a is pressed, the engine speed becomes the A speed, and when the lower side is pressed, the B speed becomes the B speed.

The engine speed memory switch 177b behind the engine speed memory switch 177a is also a seesaw switch, and automatically returns to neutral when released with a finger. When the upper side of the engine speed storage switch 177a is pressed, the engine speed increases, and when the lower side is pressed, the engine speed decreases. After selecting the A or B rotation speed (A and B are arbitrary rotation speeds) with the engine speed memory switch 177a, pressing the upper side (+ side) with the engine speed memory switch 177b increases the speed. Then, press the lower side (-side) to decrease the rotational speed. Then, the rotational speed at which the engine rotational speed storage switch 177 b is released is stored in the memory 102.

Further, an auxiliary speed change lever 179 (low speed, medium speed, high speed, road travel speed) is provided behind the throttle lever 176, and low speed 8 speed, medium speed 8 speed, high speed 8 speed, road travel speed 4 speed (high speed). (Eight upper stage 4 stages) is possible. The first sub-control lever 178a is an external hydraulic pressure takeout lever for supplying high-pressure oil when the rotary tiller 84 of the tractor is removed to drive another work machine. A sub-control lever second station 178b is disposed behind the sub-control lever first station 178a, and a third station (not shown) or a fourth station (not shown) may be provided.

The draft ratio adjustment dial 182 is a dial for adjusting the sensitivity of the draft control. The dial ratio adjustment dial 182 is set to the position side when turned to the left side, and to the draft side when turned to the right side. It becomes control to maintain the tillage depth. Further, when the draft ratio adjustment dial 182 is turned to the right, priority is given to load. That is, when a predetermined load or more is applied to the work implement, control is performed so that the work implement (such as the rotary tiller 84) is slightly increased in order to reduce the load from the tilling depth.

Therefore, the draft ratio can be adjusted according to the state of the field and the preference of the operator. Table 1 shows the relationship between the adjustment of the draft ratio and the state of the field.
(Table 1)
Draft ratio 1 5
Adjustment dial (turn counterclockwise) (turn clockwise)
Plowing depth Shallow ← → Soil to deepen Light ← → Heavy

That is, as the position is turned to the left (left side), the amount of change in the vertical movement of the rotary tiller 84 with respect to the load decreases, giving priority to the plowing depth. As the draft is turned to the right (right), the amount of change in the vertical movement of the rotary tiller 84 with respect to the load increases, and the load is reduced.

And the raising adjustment dial 183 of the rotary tiller 84 is for adjusting the height of the rotary tiller 84, and when turned to the left, the height of the rotary tiller 84 is lowered, and when turned to the right, it is raised. Become. With the raising adjustment dial 183, the height of the three-point link mechanism of the rotary tiller 84 can be adjusted. Depending on the work implement 84, it may hit the tractor body when it is raised to the highest position, but such a problem can be prevented by adjusting the height of the work implement 84. Further, the work machine 84 that does not need to be raised so much can be adjusted with the raising adjustment dial 183 to perform efficient work.

The tilt adjustment dial 184 adjusts the tilt of the rotary tiller 84. When the tilt adjustment dial 184 is turned to the left, the tilt adjustment dial 184 is raised to the right. Further, the 4WD change-over switch 185 can be switched between a traveling loader, 2WD, 4WD, full turn and 2WD turn.

The traveling loader is used during road traveling and loader work, and is usually a two-wheel drive. However, if the tractor enters a muddy area or becomes a steep slope or uneven road, it automatically becomes a four-wheel drive. Then, when the brake is applied, it automatically becomes four-wheel drive, and when it stops during driving, it becomes four-wheel drive. In other words, the four-wheel drive enables the travel brake function to be more exerted than in the case of the two-wheel drive, and the travel stop can be stably performed.

In the case of 2WD (two-wheel drive), the rear wheels 63, 63 are driven, and in the case of 4WD (four-wheel drive), the four wheels (front wheels 61, 61, rear wheels 63, 63) are driven. Further, in the full turn, the speed of the front wheels 61 and 61 is increased when turning in 4WD, and the turn becomes quick. Further, in a hard field or the like, the 2WD turn is driven by the front wheels 61 and 61 only when turning, so that the turning can be performed quickly and smoothly.

Furthermore, the horizontal cylinder 70 of the three-point link mechanism of the rotary tiller 84 can be moved by manually operating the manual raising / lowering switch 186 of the horizontal cylinder 70 (FIG. 1). And the right-and-left inclination of the rotary tiller 84 is adjusted according to the state of the field. The manual up / down switch 186 is used for attaching / detaching a working machine such as the rotary tiller 84.

Further, when the PTO on / off switch 187 is pressed and turned to the right, the PTO is turned on and the rotary tiller 84 is activated. When the PTO is turned on, the rotary tiller 84 stops when the PTO is automatically turned off. . Further, when the PTO manual automatic switch 188 is turned to the left, the manual operation is performed, and the operation of the rotary tiller 84 is manually set and operated. In this case, the rotary tiller 84 is operated by the PTO on / off switch 187. Further, when the PTO manual automatic switch 188 is turned to the right, the automatic operation is performed and the rotary tiller 84 is automatically operated. In this case, when the rotary tiller 84 is raised, the rotation of the rotary tiller 84 is automatically stopped, and when the rotary tiller 84 is lowered, the rotation of the rotary tiller 84 is automatically resumed.

When the PTO manual automatic switch 188 is set to manual, when the PTO on / off switch 187 is on and a change is made (which means a state when the PTO change lever 173 is not neutral) The shaft 14 rotates. When the PTO manual automatic switch 188 is set to automatic, the rotation is stopped by stepping on the PTO clutch pedal 119 or raising the rotary tiller 84. This function is mainly used for paddy field work.

The diff lock switch 189 is a seesaw switch. When the opposite side of the cockpit 16 is pressed, the diff lock switch is set. When the diff lock switch 189 is pressed again, the diff lock is released. In addition, in order to prevent an erroneous operation due to an operator's arm being inadvertently hit, the seat 16 side cannot be pushed.

When the position control lever 190 is tilted rearward, the rotary tiller 84 rises, and when it is tilted forward, the rotary tiller 84 descends. The work implement lift switch 191 is a seesaw switch. When the rear side is pushed once, the rotary tiller 84 is raised to the maximum position, and when the front side is pushed once, the position control lever 190 is lowered. The maximum position is a position adjusted with the raising adjustment dial 183.

Further, the travel shift switch 192a is a switch for shifting up the shift stage, and the shift stage is shifted up every time the switch is pressed, so that the low speed stage, the medium speed stage 8, the high speed stage 8 and the road speed stage 4 are set. Shifting is possible. On the other hand, the travel shift switch 192b is a switch for shifting down the shift stage, and the shift stage is shifted down every time the switch is pressed, and the speed is changed to 8 steps at low speed, 8 steps at medium speed, 8 steps at high speed, and 4 steps on the road. Shifting is possible. There is a cigar lighter 194 behind these switches.

A work machine ascent / descent monitor lamp 195 in the switch box 180 is turned on when a work machine such as the rotary tiller 84 is raised or lowered. The AT shift work sensitivity dial 196 operates when an AT shift work switch 200 (described later) is turned on. When the AT shift work switch 200 is turned on, automatic shift (auto drive) works. The AT shift work sensitivity dial 196 is a dial that changes the sensitivity of the automatic shift that automatically increases or decreases the vehicle speed. When the dial is turned to the right, the sensitivity is increased, and when it is turned to the left, the sensitivity is lowered. When the switch in the switch box 180 is not operated, the lid 211 is closed to prevent dust and the like from entering the switch box 180.

The lowering speed dial 197 is a dial for adjusting the work implement lowering speed, and when turned to the right, the speed increases and the work implement descends faster. Therefore, it is suitable for a working machine having a light weight (for example, a paddy paddy machine). On the other hand, when it is turned to the left, the speed decreases and the work machine descends slowly. In this case, it is suitable for a heavy work machine (for example, a ski work machine).

When the brake adjustment dial 198 is turned to the left, the brake is weakened, and when it is turned to the right, the brake is applied strongly. The brake adjustment dial 198 acts when an auto brake on / off switch 206 described later is turned on. When the AT shift road switch 199 is turned on, automatic shift (auto drive) is performed during road travel, and when the AT shift work switch 200 is turned on, automatic shift (auto drive) is performed during work travel.

When the connection sensitivity shift switch 201 is pressed, the connection sensitivity is turned on, and when the connection sensitivity shift switch 201 is further pressed, the connection sensitivity shift switch 201 is turned on and off, so that the connection feeling when the main transmission is shifted by the main transmission hydraulic clutch A can be changed. For example, when the connection sensitivity shift switch 201 is turned on, the lamp 201a is turned on to perform a gradual shift, and when turned off, the lamp 201a is turned off to make a quick connection (fast clutch connection). When the connection sensitivity shift switch 201 is turned off in the operation of the traction system for attaching a plow or the like to the rear portion, the connection time of the main transmission hydraulic clutch A is shortened when the main transmission hydraulic clutch A performs a shift operation of the main transmission.

Further, the connection sensitivity PTO switch 202 is turned on in the order of rotary, pasture 1 and pasture 2 each time the connection sensitivity PTO switch 202 that can change the connection manner of the PTO clutch E is pressed. When the connection sensitivity PTO switch 202 is set to a rotary, the connection of the PTO clutch E becomes faster. Mainly used in working machines such as the rotary tiller 84. As soon as the PTO shaft 14 begins to rotate, it rotates with a rotational force that does not lose the resistance of the soil in the field.

Further, when the connection sensitivity PTO switch 202 is set to pasture 1 or pasture 2, the connection of the PTO clutch E becomes loose. There are two types of shifts possible with pasture 1 and pasture 2. Mainly used for work machines that slowly connect the PTO clutch E, such as pasture work machines and snow blowers. The connection sensitivity PTO switch 202 is used on the PTO shaft 14 in the same manner as when the rotary is used.

The horizontal sensitivity switch 203 is a switch for switching the operation sensitivity of the automatic horizontal control device of the work machine. When the horizontal sensitivity switch 203 is pressed, the operation sensitivity becomes dull and the movement of the automatic horizontal control becomes slow. When the horizontal sensitivity switch 203 is pressed again, the operation sensitivity is restored. Then, when the backup on / off switch 204 is turned on, the rotary tiller 84 automatically rises when the tractor moves backward.

When the auto lift on / off switch 205 is turned on and the steering handle 73 is turned, the rotary tiller 84 is automatically raised. When the auto brake on / off switch 206 is turned on and the steering handle 73 is turned, the brake is automatically applied only to the rear wheel 63 on the inside of the turn. Then, the horizontal control switch 207 can perform horizontal control of a working machine such as the rotary tiller 84. When the horizontal selector switch 207 is pressed, the lamps are lit in the order of automatic horizontal, manual, parallel, and inclined. In the automatic level, the level is automatically maintained by a level sensor (not shown). In the case of manual operation, the tilt adjustment dial 184 is used for manual adjustment. In parallel, the rotary tiller 84 is always kept parallel to the tractor body T. And in inclination, it controls so that the rotary tiller 84 may have a fixed angle with respect to the ground.

The three-point selector switch 208 selects the three-point selector switch 208 of the switch box 180 by selecting the mounting hole of the lift cylinder 210 (FIG. 1). Select 1 for category 1 work machines (when attaching to the front hole of the lower link), and select 2 for category 2 work machines (when attaching to the rear hole of the lower link). And if the auto accelerator switch 209 raises the rotary tiller 84 in the state where it turned on, an engine speed will fall to about 1700 rpm.

INDUSTRIAL APPLICABILITY The present invention can improve the operability of a work vehicle such as a tractor, and can be used for various work vehicles such as agriculture, building, and transportation.

Fig.1 (a) is a left view of the tractor of embodiment of this invention. FIG. 1B is a simplified plan view showing the relationship between the mission case and the front and rear wheels. FIG. 2A is a perspective view of a main part near the right side of the steering handle of the tractor of FIG. 1, and FIG. 2B illustrates the operation state of the lifting lever of the rotary tiller and the operation of the rotary tiller. It is a control block diagram for this. FIG. 3 (a) is a perspective view of the main part near the left side of the steering handle in the case of a lift switch, and FIG. 3 (b) shows the operation state of the lift switch of the rotary tiller and the operation of the rotary tiller. It is a control block diagram for demonstrating. It is a motive power transmission system diagram of the tractor provided with the raising / lowering lever or the raising / lowering switch of this embodiment. It is a hydraulic circuit diagram of the tractor provided with the raising / lowering lever or the raising / lowering switch of this embodiment. It is a cross-sectional block diagram of the forward / reverse clutch cylinder which switches a forward / reverse gear. It is a torque control block diagram at the time of providing a torque sensor in the power transmission shaft of the tractor shown in FIG. It is a flow of torque control by the controller when a PTO clutch output shaft torque sensor is provided on the shaft after passing the PTO clutch E. FIG. 9 is a diagram illustrating an example in which the pressure is adjusted so as not to exceed the PTO shaft torque change line for torque control in FIGS. 7 and 8. It is a figure for demonstrating a part of flow of FIG. It is the figure which showed the flow of the torque control by a controller at the time of providing a driving shaft torque sensor in the main transmission shaft of a forward / reverse clutch. FIG. 12 is a diagram showing an example in which the pressure is adjusted so as not to exceed the main transmission shaft torque change line of torque control in FIGS. 7 and 11. It is a top view of the vicinity of the cockpit of the tractor of FIG. It is a perspective view of the vicinity of the cockpit of the tractor of FIG. FIG. 15A is a plan view of the switch box of FIGS. 13 and 14, and FIG. 15B is a side view.

DESCRIPTION OF SYMBOLS 1 Engine shaft 2 Input shaft 3 Output shaft 4 PTO interlocking shaft 5 Front wheel output shaft 6 Travel counter shaft 7 Front wheel drive shaft 8 Back counter shaft 9 PTO counter shaft 10 Rear differential shaft 11 Rear wheel shaft 12 Front differential shaft 13 Front wheel shaft 14 PTO shaft 15 , 17 gear drive shaft 16 cockpit 18 PTO transmission shaft 19 main transmission shaft (main transmission output shaft) 20 sub transmission shaft 21 creep counter shaft 22 PTO forward / reverse switching shaft 23 PTO deceleration shaft 24 PTO reverse rotation shaft 25 front wheel interlocking shaft 26 Input shaft 27 Sub-transmission counter shaft 28 Front wheel interlocking shaft 30 Armrest 31 Input gear 32 PTO transmission gear 33 Main transmission gear 34 High / low speed switching gear 35 Sub transmission gear 36 Front wheel take-out gear 37 PTO forward / reverse switching gear 38 Sub transmission counter gear 39 Main Transmission counter gear 40 High / low speed switching gear 41 Front wheel drive switching gear 42 Forward / reverse switching Gear 43 Back counter gear 44 PTO speed change counter gear 45 Rear differential 46 Differential ring gear 47 Front differential 48 Input gear 49 Creep counter gear 50 PTO reduction gear 51 Front wheel interlocking gear 52 PTO reverse rotation gear 53 Drive pinion gear 54 Front wheel interlocking gear 55 Front wheel gear 56 Switching Drive counter gear 59 Counter shaft 60 Forward / reverse switching clutch pack 61 Front wheel 62 Engine 63 Rear wheel 65 Transmission case 66 PTO clutch pack 67 Front wheel drive clutch pack 70 Horizontal cylinder 72 Front axle housing 73 Steering handle 75 Rear axle housing 76 Clutch packs 77F, 77R Return spring 78F, 78R Piston 80 Hydraulic pump 81a, 81b Pressure reducing valve 82a Brake valve 82b Pressure Control valve 83 brake cylinder 84 work machine (rotary tiller) 85 forward-reverse clutch cylinder 86 forward-reverse clutch proportional pressure control valve (switching valve)
86F, 86R Solenoid 89 Main transmission (2-4) clutch proportional pressure control valve 87, 88, 91, 92 Hydraulic clutch cylinder 93 Main transmission (1-3) clutch proportional pressure control valve 94 Switching control valve 95 High / low hydraulic clutch Cylinder 96a, 96b Control valve 97 Differential lock control valve 98a Front wheel differential lock cylinder 98b Rear wheel differential lock cylinder 99 Four-wheel drive switching clutch cylinder 100 Control processing device (controller)
DESCRIPTION OF SYMBOLS 101 Main hydraulic circuit 102 Memory 103 Power steering apparatus 104 PTO clutch cylinder 105,106 PTO clutch proportional pressure control valve 107 Orbit roll 110 Forward side clutch pressure sensor 111 Reverse side clutch pressure sensor 112 Engine speed sensor 115 Forward / reverse switching lever 116 Accelerator Lever 118 Lever 119 Clutch pedal 123 Parking brake warning light 124 Automatic shift indicator light 125 Engine tachometer 129 On / off control valve 130 Lifting lever 134 Lift arm sensor 136 Lifting solenoid 137 Lowering solenoid 138 PTO clutch solenoid 142 Traveling shaft torque sensor 145 146 Pressure sensor 151 Forward clutch output shaft torque sensor 152 Reverse clutch output shaft torque sensor 153 Main change Output shaft torque sensor 165 PTO shaft rotation sensor 167 Forward / reverse switching lever position sensor 168 Main transmission (2-4) clutch switching solenoid 169 Main transmission (1-3) clutch switching solenoid 170 Vehicle speed sensor 172 Parking brake 173 PTO change lever 175 Accelerator Pedal 176 Throttle lever 177a, b Engine speed memory switch 178a, 178b Sub control lever 179 Sub transmission lever 180 Switch box 182 Draft ratio adjustment dial 183 Raise adjustment dial 184 Tilt adjustment dial 185 4WD changeover switch 186 PTO on / off switch 187 188 PTO manual automatic switch 189 Differential lock switch 190 Position control lever 191 Elevating switch (work machine Later switch)
192a, b Traveling shift switch 194 Cigarette lighter 195 Working machine ascent / descent monitor lamp 196 AT shift work sensitivity dial 197 Lowering speed dial 198 Brake adjustment dial 199 AT shift road switch 200 AT shift work switch 201 Connection sensitivity shift switch 201a Lamp 202 connection Sensitivity PTO switch 203 Horizontal sensitivity switch 204 Backup on / off switch 205 Auto lift on / off switch 206 Auto brake on / off switch 207 Horizontal selector switch 208 Three-point selector switch 209 Auto accelerator switch 210 Lift cylinder 211 lid A Main transmission hydraulic clutch B High Low transmission clutch C Sub transmission gear transmission mechanism D Forward / reverse clutch E PTO clutch T Tractor body

Claims (2)

In a work vehicle including a steering handle (73) and a cockpit (16) and connected to a work machine (84),
The lifting lever (130) of the working machine (84), which is located in the vicinity of the steering handle (73) and can be operated in two stages in one direction and the other direction, and the lifting lever (130) A control processing device (100) for operating the work machine (84) by processing the operation information when the is operated,
The control processor (100), the incoming or cut operation of the lift lever (130) to one direction or the other to each of the working machine is operated in a first stage (84), the working machine (84 when operated in the inlet side of the actuation of) it lowers to the pre-Symbol working machine (84) operating in a second stage, the second stage is when operating in the cut-side of the operation of the work machine (84) It is configured to perform a process of raising the work machine (84) when operated ,
Specified torque (b) after constituting the PTO clutch (E) for power connection / disconnection to the work machine (84) and subtracting the influence of the centrifugal force of the clutch from the rotational speed of the upper shaft of the PTO clutch (E) And the PTO clutch (E) is connected so that the prescribed torque (b) is obtained . The work vehicle according to claim 1, wherein a connection sensitivity PTO switch (202) for speeding up or slowing down the connection of the PTO clutch (E) is configured in the switch box (180) .

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