JP2010052603A - Traveling device of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission of a working vehicle improving durability of the vehicle and safety during traveling of the vehicle with wear of the wheels prevented from developing by allowing switching from a two-wheel driving state to a four-wheel driving state to take place only when the four-wheel driving state is really required. <P>SOLUTION: This traveling device includes a control device which makes an automatic driving state switching mode (A) by a 4WD/2WD changeover switch, is provided with an update storage function part performing processing to update rotation frequency ratio T of rear wheels and front wheels deviated from a reference value as a new reference value when the rotation frequency ratio satisfies a prescribed requirement and to store the reference value in a memory when the vehicle is traveling in a two-wheel driving state (C), and the rotation frequency ratio T is deviated from the reference value of the rotation frequency ratio T stored in the memory in advance (G), and switches from the two-wheel driving state to the four-wheel driving state when the rotation frequency ratio of the rear wheels and front wheels is deviated from the new reference value updated and stored in the memory (K). As a result, the driving state is not switched when the rotation frequency ratio is normally deviated from the reference value stored in advance, but an unnecessary switching can be prevented by applying the fixed brake. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a work vehicle connected with work machines for agriculture, construction, transportation, etc., and more particularly to a traveling device such as a tractor.

When a work vehicle such as a tractor travels, a slip is likely to occur depending on the field conditions (for example, undulation of the field surface, softness, etc.). In particular, slipping occurs remarkably in soft fields and wet fields. When the wheel of the work vehicle slips in this manner, the traction force of the work machine equipped is reduced, so that conventionally, the work load is reduced to prevent the wheel from slipping.
Further, in Patent Document 1 below, a two-wheel drive state with both left and right non-steering wheels (rear wheels), both non-steering wheels (rear wheels), and left and right so as not to cause a reduction in traction force of the work machine as much as possible. Driving state switching means capable of switching between the four-wheel driving state for driving the steering wheel (front wheel) and a pair of rotation detection means for detecting the rotational speeds of the left and right rear wheels, respectively, and a two-wheel driving state When the slip ratio of the left and right non-steering wheels (rear wheels) exceeds a predetermined value, the driving state switching means and the rotation detecting means are linked so that the four-wheel driving state is automatically switched. A traveling transmission device for a working machine is disclosed.

According to the configuration described in Patent Document 1, when the rear wheel slip becomes noticeable to some extent in the two-wheel drive state, the state automatically switches to the four-wheel drive state. Therefore, when the difference in rotational speed between the left and right non-steering wheels is increased to some extent, the two-wheel drive state is switched to the four-wheel drive state in order to reduce the drive loss due to the slip. When it decreases, the number of driving wheels is increased to recover the reduced traction force. This configuration compensates for the reduced traction force only when the traction force is reduced due to slip, compared to the case of constant four-wheel drive, so the necessary traction force is ensured and the fluctuation range of the traction force is reduced. it can.
Japanese Patent Laid-Open No. 10-114229

  As described above, in the configuration described in Patent Document 1, the left and right non-steering wheels during two-wheel drive traveling with respect to a preset reference value that is the difference between the rotational speeds of the left and right non-steering wheels of the work vehicle. Judgment was made based on the difference in rotation speed. When the difference in rotational speed between the left and right non-steering wheels during two-wheel drive traveling exceeds the reference value, the two-wheel drive state is automatically switched to the four-wheel drive state. If the ground grip is good when traveling, the left and right non-steering wheels rotate at the same speed and there is no speed difference, but if either the left or right non-steering wheel slips, the slip-side non-steering wheel The driving speed increases, and the driving speed of the other non-steering wheel decreases accordingly.

  However, if there is wheel wear or the like, the difference between the rotational speeds of the left and right non-steering wheels during two-wheel drive traveling may deviate from the reference value even if slip does not occur. Therefore, when there is wear of the wheels, etc., it becomes easy to switch to the four-wheel drive state regardless of slip, and even though the two-wheel drive state is originally sufficient, it becomes the four-wheel drive state and further wear. Has been promoted. In the four-wheel drive state, the rotation speed of the front wheels and the rotation speed of the rear wheels are driven by the gear ratio in the transmission case, but the actual rotation of the front wheels and the rotation of the rear wheels is the theoretical transmission ratio. A slight shift occurs. This shift causes the wheel (tire) to slip away, and the front and rear wheels wear out little by little. When the wear of the wheels of the work vehicle is promoted, the durability of the wheels and the vehicle itself is inferior. If possible, it is desirable that the safety during traveling is high.

  The object of the present invention is to switch from a two-wheel drive state to a four-wheel drive state only when a true four-wheel drive state is necessary, and without promoting the wheel wear, To provide a traveling device for a work vehicle such as a tractor with improved safety during traveling.

The problems of the present invention are solved by the following means.
The invention according to claim 1 includes a front wheel (61) and a rear wheel (63), a two-wheel drive state in which the rear wheel (63) is driven, and four wheels in which the rear wheel (63) and the front wheel (61) are driven. Driving state setting means (185) that can be set to a plurality of modes including a driving state automatic switching mode that automatically switches the driving state to the driving state according to the road surface state, and the rotational speed of the rear wheel (63) And a rotational speed detection means (112a, 112b) for detecting the rotational speed of the front wheel (61) and a preset rotational speed ratio of the rear wheel (63) and the front wheel (61) (front wheel rotational speed). (Rear wheel rotation speed) is provided with a storage unit (100d) for storing a reference value, and when the drive state automatic switching mode is set by the drive state setting means (185), it corresponds to the road surface state. Switching between two-wheel drive state and four-wheel drive state The rotational speed ratio between the rear wheels (63) and the front wheels (61) detected by the rotational speed detection means (112a, 112b) when the vehicle is traveling in a two-wheel drive state is the storage unit (100d). And a control device (100a) for performing a process of switching from the two-wheel drive state to the four-wheel drive state when it deviates from the reference value stored in or near the reference value. (100a) after the drive state automatic switching mode is set by the drive state setting means (185) and the vehicle is running in the two-wheel drive state and is detected by the rotation speed detection means (112a, 112b). When the rotational speed ratio between the wheel (63) and the front wheel (61) deviates from the reference value stored in the storage unit (100d) or the vicinity thereof, the rotational speed ratio deviating from the reference value or the vicinity thereof is a predetermined value. Meet the requirements An update storage function unit that performs a process of updating the rotation speed ratio deviating from the reference value or the vicinity thereof as a new reference value and storing it in the storage unit (100d), and the update storage function unit After storing, the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detecting means (112a, 112b) is updated and stored in the storage unit (100d) by the update storage function unit. This is a traveling device for a work vehicle that performs processing to switch from a two-wheel drive state to a four-wheel drive state when it deviates from the new reference value or its vicinity.

  The invention according to claim 2 is a front wheel (61), a rear wheel (63), a two-wheel drive state in which the rear wheel (63) is driven, and four wheels in which the rear wheel (63) and the front wheel (61) are driven. Driving state setting means (185) that can be set to a plurality of modes including a driving state automatic switching mode that automatically switches the driving state to the driving state according to the road surface state, and the rotational speed of the rear wheel (63) And a rotational speed detection means (112a, 112b) for detecting the rotational speed of (61) and a preset rotational speed ratio of the rear wheel (63) and the front wheel (61) (front wheel rotational speed / A storage unit (100d) for storing a reference value that is the number of rear wheel revolutions), and when the drive state automatic switching mode is set by the drive state setting means (185), 2 according to the road surface state. Switching process between wheel drive state and four wheel drive state The rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detection means (112a, 112b) when the vehicle is traveling in a two-wheel drive state is stored in the storage unit (100d). A traveling device for a work vehicle provided with a control device (100a) for performing a process of switching from a two-wheel drive state to a four-wheel drive state when it deviates from a stored reference value or the vicinity thereof, the control device (100a ) Is a rear wheel (in which the driving state automatic switching mode is set by the driving state setting means (185) and the vehicle is running in the two-wheel driving state and is detected by the rotation speed detecting means (112a, 112b). 63) When the rotational speed ratio between the front wheel (61) deviates from the reference value stored in the storage unit (100d) or its vicinity, the rotational speed ratio deviated from the reference value or its vicinity satisfies a predetermined requirement. Fulfill Is provided with an update storage function unit for performing processing for updating the rotation speed ratio deviating from the reference value or the vicinity thereof as a new reference value and storing it in the storage unit (100d). After the storage, if the total traveling time of the work vehicle is less than a predetermined time, the rotation speed detection means (112a, 112b) uses the reference value that is preset and stored in the storage unit (100d) as a reference. When the detected rotation speed ratio of the rear wheel (63) and the rotation speed of the front wheel (61) deviate from the reference value stored in the storage unit (100d) or the vicinity thereof, the four-wheel drive from the two-wheel drive state is performed. On the other hand, when the total traveling time of the work vehicle is longer than a certain time, the rotational speed is detected based on the new reference value updated and stored in the storage unit (100d) by the update storage function unit. 2 when the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the means (112a, 112b) is updated to the storage unit (100d) and deviates from the stored new reference value or its vicinity. A traveling device for a work vehicle that performs a process of switching from a wheel drive state to a four-wheel drive state.

According to the first aspect of the present invention, the rotational speeds of the left and right rear wheels (63, 63) detected by the rotational speed detection means (112a, 112b) during traveling in the two-wheel drive state and the left and right front wheels (61 , 61) If the ratio of the rotational speeds deviates from the reference value stored in the storage unit (100d) or its vicinity, and satisfies the predetermined requirement, the ratio of the rotational speeds deviated from the reference value or its vicinity Is changed, updated and stored in the storage unit (100d) as a new reference value.
Accordingly, when the ratio between the rotational speeds of the left and right rear wheels (63, 63) and the rotational speeds of the left and right front wheels (61, 61) deviates from the reference value stored in advance in the storage unit (100d), the two-wheel drive state is always achieved. Instead of switching from the four-wheel drive state to the four-wheel drive state, the set reference value is updated under predetermined requirements, and the two-wheel drive state is switched from the two-wheel drive state to the four-wheel drive state based on the updated and stored new reference value. Thus, it is possible to switch from the two-wheel drive state to the four-wheel drive state only when it is necessary to truly switch to the four-wheel drive state by applying a fixed pawl and preventing unnecessary switching. Accordingly, the durability of the wheels (61, 63) and the vehicle itself and the safety during traveling are improved without promoting the wear of the wheels (61, 63).

  According to the second aspect of the present invention, when the total traveling time of the work vehicle is less than a predetermined time, the two-wheel drive state is set based on the reference value that is preset and stored in the storage unit (100d). When the total traveling time of the work vehicle is longer than a certain time, the update storage function unit updates the storage unit (100d) and uses the stored new reference value as a reference for the two-wheel drive state. To the four-wheel drive state.

  When the total travel time of the work vehicle is short, the wheels (61, 63) wear little, so there is no problem by controlling with a theoretical value that is a preset reference value. However, when the total travel time of the work vehicle increases, the four-wheel drive from the two-wheel drive state according to the rotational speed of the wheels (61, 63) that gradually changes due to wear of the wheels (61, 63). Since the reference value for the state is replaced, it is possible to switch from the two-wheel drive state to the four-wheel drive state with a new reference value suitable for the wear state of the wheels (61, 63).

  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, it demonstrates below by taking as an example the tractor which is an example of a working vehicle.

  FIG. 1 shows a left side view of a tractor equipped with a traveling device according to an embodiment of the present invention, and FIG. 2 shows a power transmission diagram in the transmission of the tractor of FIG. Further, FIG. 3 shows a hydraulic circuit diagram of the power transmission diagram of FIG. 2, and FIG. 4 shows a configuration diagram of a hydraulic clutch cylinder for turning on and off the power of the transmission of FIG. FIG. 5 is a control block diagram of the tractor shown in FIG.

  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 (FIGS. 6 and 7). A work machine such as a rotary tiller can be mounted on the rear part of the vehicle body T so as to be lifted and lowered by a three-point link mechanism. The vehicle body T has an engine 62 mounted on the front end via an engine bracket that is supported on a front axle housing (not shown), 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 (not shown) is provided at the rearmost portion of the transmission case 65, and the rear wheels 63 are mounted on the left and right sides.

FIG. 2 shows a power transmission diagram in the transmission of the tractor of FIG.
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 transmission 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 extends along the rear axle housing. The rear differential shaft 10 mounted on the shaft and the rear wheel shaft 11 are interlocked via a planetary reduction mechanism. The front wheel output shaft 5 is connected to the input shaft 26 of the front differential 47 provided at the center of the front axle housing from the lower portion of the transmission case 65 through the lower portion of the engine 62, and is mounted along the front axle housing. The front differential shaft 12 and the planetary reduction mechanism are connected to the front wheel shaft 13. Note that gear drive shafts 15 and 17 for taking out power from the input shaft 2 to the hydraulic pump 80 (FIG. 3) are arranged in parallel with the input shaft 2.

  2 is provided with 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 / reverse 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 front and rear independent 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. 3) to be described later is referred to as a forward / reverse hydraulic clutch D.
Further, a forward / reverse switching lever 115 (FIG. 6) 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. 6) is provided under the foot of the handle post. As for the operation position of the clutch pedal 119, a sensor signal is input from the clutch pedal sensor 119a to the controller 100a.

  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 by a hydraulic operation to shift to the low speed position, 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. When the front wheel drive clutch pack 67 is switched by a hydraulic operation and shifted to a high speed position, the front wheel 61 is moved to the rear wheel 63 by about 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. 3 shows a hydraulic circuit diagram of the power transmission diagram of FIG.
In the hydraulic circuit diagram of FIG. 3, 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 105, 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 supplied to a hydraulic clutch cylinder 88 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 87 and further operates the first speed gear 3 and the third speed gear 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 81a is switched by a switching valve 86 (forward solenoid 86F, forward hydraulic clutch D) that switches between the forward and reverse hydraulic clutches D of the forward / reverse clutch cylinder 85 via the on / off control valve 129 of the forward / reverse clutch cylinder 85. The reverse solenoid 86R) is supplied. The forward clutch pressure sensor 110 (FIG. 5) and the reverse clutch pressure sensor 111 (FIG. 5) detect whether the hydraulic oil is supplied to the forward or reverse hydraulic clutch D of the forward / reverse clutch cylinder 85. it can. Further, a forward / reverse boost solenoid 90 (also referred to as a linear boost solenoid) for boosting the hydraulic pressure of the forward / reverse clutch D is provided.

  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 passage on the inlet side to each hydraulic clutch cylinder. Pressure sensors 145a to 145d, pressure sensor 146 of PTO clutch E, Hi (high) clutch pressure sensor 113, Lo (low) clutch pressure sensor 114, and the like.

  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 control valves (solenoids) 96a and 96b for switching the high / low hydraulic clutch cylinder 95 operated via
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.
Also, the hydraulic pressure from the hydraulic pump 80 shown in FIG. 3 is configured to supply hydraulic oil to the orbit roll 107 that is operated by operating the power steering handle 73.

FIG. 4 shows a cross-sectional configuration diagram of a forward / reverse clutch cylinder 85 that switches between the forward / reverse gears 42 and 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.

  FIG. 5 is a block diagram showing input and output of control signals to the controllers (control devices) 100a to 100c. The traveling system controller 100a that controls the traveling speed, the engine controller 100b that controls the output of the engine 62, and the working machine. A work machine lifting / lowering system controller 100c for controlling the lifting / lowering is connected by a communication line to exchange control signals.

  First, the travel system controller 100a receives the on / off information of each clutch of the friction clutch of the main transmission hydraulic clutch A described above from the transmission 1 clutch pressure sensor 145a, the transmission 2 clutch pressure sensor 145b, the transmission 3 clutch pressure sensor 145c, and the transmission. 4-clutch pressure sensor 145d is input, and high / low shift clutch B on / off information is input from Hi clutch pressure sensor 113 and Lo clutch pressure sensor 114, and on / off information of clutch pack 60 of forward / reverse switching clutch D is input. Are input from the forward clutch pressure sensor 110 and the reverse clutch pressure sensor 111, and the forward / reverse lever operating position sensor 115a for detecting the shift position of the forward / reverse lever 115 for shifting the forward / reverse switching clutch D and the shift position of the auxiliary shift lever 179. Sub-shift lever operating position sensor 17 for detecting Shift position information is input to the travel system controller 100a f. From

  Further, the oil temperature in the transmission case 65 is input to the traveling system controller 100a from the transmission oil temperature sensor 147, the position of the clutch pedal 119 is input from the clutch pedal operation position sensor 119a, and the rotational speed of the front wheels 61 and 61 is increased. From the front wheel drive shaft rotational speed sensor 112a (FIG. 2) for detecting the rotation and the rear wheel drive shaft rotational speed sensor 112b (FIG. 2) for detecting the rotational speed of the rear wheels 63, 63, the drive shaft rotational speed of the wheels 61, 63 is detected. Is entered. In addition, from a 4WD / 2WD selector switch (switching switch for 4WD (both front and rear wheels are driven)) and 2WD (switch only for rear wheels) 185, which will be described later, information on the selected driving state is input from a sensor (not shown). Is done.

  The front wheel break angle sensor 116 is a sensor that detects the steering angle of the front wheels 61 and 61 corresponding to the turning operation of the steering handle 73, and the steering angle of the front wheels 61 and 61 is input from the front wheel break angle sensor 116. .

  Furthermore, whether or not accelerator shift information (automatic shift (auto-drive) described later) is set in the travel system controller 100a from an accelerator shift setting switch (which will be described later on an AT shift road switch 199 and an AT shift work switch 200). Accelerator for detecting the depression position of the accelerator pedal 175 (the amount of operation of the accelerator lever 176 when working). Accelerator setting information is input from the position sensor 175a, and setting information is input from the accelerator fine adjustment lever 153 (FIGS. 6 and 7). The accelerator fine adjustment lever 153 is a rebound type push switch, and the adjustment value changes step by step each time it is pressed.

  A control signal output from the traveling system controller 100a includes a switching signal to the forward / reverse switching solenoids 86F and 86R of the hydraulic valve 86 for operating the clutch pack 60 of the forward / reverse switching clutch D and a linear boost solenoid 90 (forward / reverse boost solenoid). Switching boost signal, neutral operation signal to clutch solenoid 129a (solenoid of on / off control valve 129), main shift (1-3) clutch proportional pressure control valve 93 to 1-3 speed switching solenoid 93a switching signal And a boost signal to the 1-3 speed boost solenoid 93b, a switch signal to the shift 2-4 switch solenoid 89a of the main shift (2-4) clutch proportional pressure control valve 89, and a boost signal to the shift 2-4 boost solenoid 89b , The hydraulic clutch Hi clutch switch for switching the high / low hydraulic clutch cylinder 95 (FIG. 3) A high-low switching signal to the maytansinoid 96a and Lo clutch switching solenoid 96b. Further, it is an operation signal to the front wheel speed increasing 4WD solenoid 121 and the front wheel constant speed 4WD solenoid 122 for driving and adjusting the speed of the front wheels 61 and 61.

  The information signal input to the engine controller 100b includes the exhaust temperature from the engine exhaust temperature sensor 164, the rotational speed from the engine rotation sensor 165, the oil pressure from the engine oil pressure sensor 166, and the cooling from the engine water temperature sensor 167. The control signal output from the engine controller 100b at the water temperature and the common rail pressure from the rail pressure sensor 168 is a pressurization signal to the fuel high pressure pump 169 and a fuel injection signal to each high pressure injector 170.

  The information signal input to the work implement lifting system controller 100c includes the position information of the work implement from the position control lever 190 for adjusting the position of the work implement and the lift arm sensor 161 of the lift cylinder (not shown). Arm position information, restriction position information of the raising position restriction dial (raising adjustment dial) 183 for restricting the raising position of the work implement, and a lowering speed adjustment dial (lowering speed dial) for restricting the lowering speed of the work implement The control signal output from the work implement lifting system controller 100c, which is the lowering speed information of 197, is lifted to the main lift solenoid 171a and the main lift solenoid 171b of the hydraulic cylinder valve that operates the left and right lift arms (not shown). Signal.

  The meter panel 213 displays detection information of each sensor and switch setting information, and various setting signals are input from the operation panel 181 around the cockpit seat 16 including the switch box 180 (FIGS. 6 and 7).

6 shows a top view of the vicinity of the cockpit of the tractor of FIG. 1, FIG. 7 shows a perspective view of the same, and FIG. 8A shows the switch box 180 shown in FIGS. A plan view is shown, and FIG. 8B shows a side view of FIG.
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) -1st 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 pilot seat 16 of the tractor, an accelerator pedal 175 and an accelerator lever 176 (increase the engine speed when it is tilted forward, it becomes idling when it is closest to the front), and further a farm field, construction, civil engineering workshop, etc. There is an engine speed storage switch 177a for setting an engine speed at the time of work in a work area (hereinafter referred to as “farm field”) and storing it in a memory (storage unit) 100d. The engine speed storage switch 177a is a so-called seesaw switch. When the upper or lower side is pressed and the finger is released, the engine speed storage switch 177a automatically returns to the non-pressed state. Further, the memory 100d of the controller (control device) 100a can store two kinds of engine speeds, and is 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. When the upper side is pressed and the finger is released, the engine speed memory switch 177a returns to the position before the press, but the switch 177a is in the on state, and the engine speed is controlled and held by the controller 100a so that it becomes the A speed. Is done. Similarly, when the lower side is pressed and the finger is released, the engine speed storage switch 177a returns to the position before the press, but the switch 177a is in the on state, and the engine speed is controlled to the B speed by the controller 100a. Retained.

  In the case of the present embodiment, an example in which two different engine speeds can be stored is shown, but a configuration in which three or more higher engine speeds can be stored may be used. In this case, it is necessary to change the switch. For example, when the switch is configured to see up and down and to the left and right, four rotational speeds can be stored.

  The engine speed setting switch 177b behind the engine speed memory switch 177a is also a seesaw switch. When the upper side or the lower side is pressed and the finger is released, the state automatically returns to the non-pressed state. Then, after pressing the engine speed memory switch 177a (upper or lower), pressing the upper side of the engine speed setting switch 177b in the pressed state increases the engine speed, or pressing the lower side rotates the engine speed. The number goes down. The engine speed storage switch 177a does not have to be pressed. The newly set rotation speed is stored in the memory 100d.

  Further, an auxiliary transmission lever 179 (low speed, medium speed, high speed, road speed) is provided behind the accelerator lever 176 as an auxiliary transmission operation means. The low speed is 8 speeds, the medium speed is 8 speeds, the high speed is 8 speeds, It is possible to change the speed such as a road traveling speed of 4 speeds (upper 4 speeds of 4 speeds). The auxiliary transmission lever 179 operates in the front-rear direction and the left-right direction along the lever guide 179a. When it is tilted to the front right side, it moves at a high speed 179c, when it is tilted to the front left side, it travels on the road 179b. When defeated, the speed becomes 179e. The front-rear direction position and the left-right direction position are detected by a sub-shift lever position sensor (not shown), and the sensor signal is input to the controller 100a (FIG. 5). In addition, operations of gear stages such as main shift increase / decrease switches (sensors) 192a and 192b described later are also input to the controller 100a.

  Further, sensor signals from a forward / reverse lever sensor 115a (FIG. 5) for detecting the operation position of the forward / reverse switching lever 115 and an accelerator position sensor 175a (FIG. 5) for detecting the depression position of the accelerator pedal 175 are input to the controller 100a. Thus, control according to each operation content is performed by the controller 100a.

FIG. 2 shows an enlarged view of the auxiliary transmission gear transmission mechanism C.
When the position of the auxiliary transmission lever 179 is low, the gear 137 meshes with the gear 139, and the transmission flow is the auxiliary transmission shaft 20, the auxiliary transmission gear 35, the auxiliary transmission counter gear 38, the gear 134, the gear 140, the gear 135, and the creep counter. The gear 49a, the creep counter gear 49b, the gear 136, the gear 139, the gear 137, and the output shaft 3 are provided.
When the position of the auxiliary transmission lever 179 is medium speed, the gear 131 meshes with the gear 133, and the transmission flow is the auxiliary transmission shaft 20, the auxiliary transmission gear 35, the auxiliary transmission counter gear 38, the gear 134, the gear 140, the gear 133, and the gear. 131, the output shaft 3.

When the position of the auxiliary transmission lever 179 is high, the gear 131 meshes with the gear 130, and the transmission flow is the auxiliary transmission shaft 20, the auxiliary transmission gear 35, the gear 130, the gear 131, and the output shaft 3.
At the road traveling speed, there is no change in the position of the sub-shift lever, and it is in the high-speed position, and the upper four speeds (5-speed to 8-speed) are used.

  The sub-transmission gear transmission mechanism C in the transmission has three stages, but the shift position of the sub-transmission lever 179 is four stages (low speed 179e, medium speed 179d, high speed 179c, road traveling speed 179b). Since the main transmission hydraulic clutch A has four stages and the high / low transmission clutch B has two stages, the number of shift stages corresponding to the sub-shift positions at low speed, medium speed, and high speed is eight. That is, the sub-shift is 8 steps at low speed, the sub-shift is 8 steps at medium speed, and the sub-shift is 8 steps at high speed. The road running speed is four steps on the upper side (high speed side) of the high speed of eight steps, and only the upper four steps are used by the controller 100a. Therefore, even if the auxiliary transmission lever 179 is set to the road traveling speed, the transmission mechanism in the transmission does not move and remains at the high speed position.

  The first sub-control lever 178a is an external hydraulic pressure takeout lever for supplying high-pressure oil when the rotary tiller device of the tractor is removed to drive another working 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, becomes the draft side when turned to the right side, and is set regardless of the load as it is set to the position side (left side). This is the 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 load greater than a predetermined value acts on the work implement, control is performed so that the lifting cylinder of the work implement (not shown) of the work implement (rotary tillage device, etc.) is slightly raised in order to reduce the load below the working 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 ← → Deeper Soil Light ← → Heavy

  In other words, as the position is turned to the position side (left), the amount of change in the vertical tillage of the rotary tiller with respect to the load decreases, and the plowing depth is given priority. As the draft is turned to the right (right), the amount of change in the lift of the rotary tiller with respect to the load increases and the load is reduced.

  The raising adjustment dial 183 of the rotary tiller is for adjusting the height of the rotary tiller, and when turned to the left, the height of the rotary tiller is lowered, and when turned to the right, the height is increased. With the raising adjustment dial 183, the height of the three-point link mechanism of the rotary tiller can be adjusted. Depending on the working machine, it may hit the tractor body when it is raised to the highest level, but such a problem can be prevented by adjusting the height of the working machine by the expansion and contraction of the lift cylinder. In addition, a work machine 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, and when it is turned to the left, it goes up to the right, and when it is turned to the right, it goes down to the right.

FIG. 9 shows an enlarged view of the 4WD / 2WD changeover switch 185.
The 4WD / 2WD selector switch 185 switches between a two-wheel drive state in which the rear wheels 63 and 63 are driven and a four-wheel drive state in which the four wheels of the front wheels 61 and 61 and the rear wheels 63 and 63 are driven. This is a possible driving state setting means. That is, it is a switch for setting the driving state of the front wheels 61 and 61. Specifically, the 4WD / 2WD switch 185 can be switched and set to a mode such as a traveling loader, 2WD, 4WD, full turn, 2WD turn, or the like. The setting information is input from the 4WD / 2WD changeover switch (sensor) 185 to the controller 100a, and drive control is performed based on the following description.

  The travel loader is used for traveling on the road, loading / unloading of trucks, work on slopes, entering / leaving farm fields, loader work, and the like, and is usually 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. When the tractor enters a muddy state, a slip state occurs and the difference in rotational speed between the front wheels 61 and the rear wheels 63 exceeds a specified value. In addition, if the road becomes a steep slope, the vehicle speed decreases and the engine rotational speed decreases. Therefore, when the road is uneven, the four-wheel drive is automatically performed due to frequent changes in the engine speed, a difference in the speed between the front wheel 61 and the rear wheel 63, a change in the horizontal position of the work implement, and the like.

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 two-wheel drive is switched to the four-wheel drive in accordance with the road surface state as described above (and the steering (turning) angle is changed by about 1/4 of the full stroke from the neutral position). By using the four-wheel drive, the traveling brake function is exhibited more than in the case of the two-wheel drive, and the driving force to the road surface is increased so that the traveling can be stopped stably.
Thus, the traveling loader is in a drive state automatic switching mode in which the two-wheel drive is automatically switched to the four-wheel drive.

  When the 4WD / 2WD selector switch 185 is 2WD (two-wheel drive), the rear wheels 63 and 63 are driven, and when 4WD (four-wheel drive) is used, the four wheels (front wheels 61 and 61 and rear wheels 63 and 63) are driven. Drive. Further, in the full turn, the speed of the front wheels 61 and 61 is increased at the time of turning in 4WD, and the turning is quick and the turning is quick. During a full turn, a full turn indicator lamp (not shown) on the meter panel 213 is turned on.

  Furthermore, the 2WD turn is a two-wheel drive of the front wheels 61 and 61 only at the time of turning in a hard field or the like, and the turning is quick and smooth. The rotation speed of the left and right front wheels 61, 61 is a front wheel drive shaft rotation speed sensor (rotation speed detection means for the front wheels 61, 61) 112a (FIGS. 2 and 5) provided on the bevel gear of the shaft 12 (or the shaft 13). The rotational speeds of the left and right rear wheels 63 and 63 are detected by a rear wheel drive shaft rotational speed sensor (rotational speed detecting means for the rear wheels 63 and 63) 112b (FIGS. 2 and 5) provided on the rear wheel shaft 11. Detected. Based on the sensor values detected from these drive shaft rotational speed sensors 112a and 112b, the controller 100a controls the front wheel acceleration 4WD solenoid 121 and the front wheel constant speed 4WD solenoid 122 to change the speed of the front wheels 61 and 61. To do.

Further, by manually operating a manual raising / lowering switch 186 of a horizontal cylinder (not shown), a horizontal cylinder of a three-point link mechanism such as a rotary tiller can be moved. And the right-and-left inclination of a rotary tiller is adjusted with the state of a farm field. The manual raising / lowering switch 186 is used for attaching / detaching a working machine such as a rotary tiller.
Further, when the PTO on / off switch 187 is pressed and turned to the right, the PTO is turned on and the rotary tiller is activated. When the PTO is turned on, the rotary tiller is stopped when the PTO is automatically turned off. Further, when the PTO manual automatic switch 188 is turned to the left, it becomes manual, and the operation of the rotary tiller is manually set and operated. In this case, the rotary tiller is always operated when the PTO shift is turned on 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 automatically. In this case, when the rotary tiller is raised, the rotation of the rotary tiller is automatically stopped, and when the rotary tiller is lowered, the rotation of the rotary tiller is automatically resumed.

  When the PTO manual automatic switch 188 is set to the manual side, 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 PTO shaft 14 rotates. When the PTO manual automatic switch 188 is set to the automatic side, the rotation is stopped by stepping on the clutch pedal 119 or raising the rotary tiller. 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 cockpit 16 side cannot be pushed.

And the work implement position lever 190 for controlling the raising / lowering position of the work implement is disposed on the armrest portion 30 on the right side of the cockpit 16, and when the work implement position lever 190 is tilted to the rear side, the work implement rises, When the machine is tilted forward, the work implement descends. By detecting the operation angle of the work machine position lever 190 with a potentiometer (not shown), the work machine moves up and down according to the detected value.
The work implement lift switch 191 is a seesaw switch. When the rear side is pushed once, the rotary tiller is raised to the maximum position, and when the front side is pushed once, the work implement lift lever 191 is lowered to the set position of the work implement position lever 190. The maximum position is a position adjusted with the raising adjustment dial 183.

Further, main shift increase / decrease switches 192a and 192b as main shift operating means are switches for shifting up (shifting down) the shift stage of the main shift, and the shift stages (low speed, middle speed) operated by the sub shift lever 179. Speed, high speed, road speed) for further manual shifting. As described above, the main gear speed increase / decrease switch 192a, 192b further reduces the low speed to 8 speeds (1st to 8th speed main shift position), the medium speed to 8 speeds (1st speed to 8th speed main shift position), and the high speed to Further, it is possible to shift to 8 speeds (1st to 8th main shift position) and a road traveling speed to 4th speed (usually high speed 5th to 8th main shift position).
The main shift speed increasing switch 192a is a switch for shifting up the shift stage (main shift position) of the main shift, and the shift stage is shifted up each time it is pressed, and the main shift deceleration switch 192b is shifted down the shift stage. This switch shifts the gear position every time it is pressed. Regardless of the engine speed, when manually operated, the speed is changed according to the operated gear.

There is a cigar lighter 194 behind these switches. A work machine ascent / descent monitor lamp 195 in the switch box 180 is lit when a work machine such as a rotary tiller is raised or lowered. The AT shift work sensitivity dial 196 acts when an AT shift work switch 200 described later is turned on.
When the AT shift work switch 200 is turned on, an automatic shift (auto drive) described later operates, but the AT shift work sensitivity dial 196 is a dial that changes the sensitivity of the automatic shift that automatically increases and decreases the vehicle speed. Turn to the right to increase sensitivity and turn to the left to decrease sensitivity. 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.

  Further, when the AT shift road switch 199 is turned on, an appropriate gear position of the upper four speeds of the eight auxiliary gear shift high speeds according to the engine speed when traveling on the road with the auxiliary gear shift lever 179 set to the road traveling speed. The automatic shift function capable of shifting automatically is turned on, and automatic shift control is performed. When the AT shift road switch 199 is turned on, even if the main shift increase / decrease switches 192a and 192b are operated, the shift is made only by depressing the accelerator pedal 175.

Note that the main shift increase / decrease switch 192a, 192b is manually operated when the AT shift road switch 199 is turned off. When the sub-shift is on the road, the upper four speeds (5 to 8) of the sub-shift high speed are used. When the AT shift road switch 199 is off, the main shift increase / decrease switches 192a and 192b are operated. Thus, for example, when the third speed to the eighth speed are set, and then the AT shift road switch 199 is turned on, the automatic shift is performed between the third speed and the eighth speed only by operating the accelerator pedal 175.
When the AT shift work switch 200 is turned on, the main shift position (8th speed from 1st to 8th speed) in the memory 100d has the longest usage time at each position (low speed, medium speed, high speed) of the auxiliary speed change lever 179. However, when the AT shift work switch 200 is turned on and the sub-shift lever 179 is operated to shift (low speed, medium speed, high speed), the main shift position stored in the memory 100d is reached. The gear is automatically shifted.

  If the AT shift on-road switch 199 is turned on when the sub-shift lever 179 is on the road at the road speed, the shift is automatically controlled according to the engine speed, and the vehicle is running only by operating the clutch 119 when starting and stopping. No shifting operation is required. Even if the clutch pedal 119 is not depressed, if the forward / reverse switching lever 115 is neutral, the vehicle body T is in a stopped state. If the accelerator pedal 175 is depressed by operating the forward / reverse switching lever 115, the acceleration is accelerated. While automatic shifting. During automatic shift (automatic drive) control, the vehicle is automatically shifted so that the vehicle speed corresponds to the engine speed corresponding to the amount of depression of the accelerator pedal 175.

  That is, when the accelerator pedal 175 is depressed, the engine speed becomes high and the current main shift position (the current shift position of the eight-speed shifts of the main shift hydraulic clutch A and the high / low shift clutch B in FIG. 2). However, if the vehicle speed cannot be increased even after accelerating in the case of acceleration (except for the 8th speed since it is not higher than the 8th speed), the controller 100a shifts up to the current shift position. When decelerating by stepping on the brake, the accelerator pedal 175 is not stepped on, so the gear is automatically shifted to a shift position corresponding to the vehicle speed.

  When the connection sensitivity shift switch 201 is pressed, the connection sensitivity is switched on when the connection sensitivity shift switch 201 is pressed again. When the connection sensitivity shift switch 201 is switched on and off, the connection feeling when the main shift 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 can change the way the PTO clutch E is connected. Each time the connection sensitivity PTO switch 202 is pressed, the light is turned on in the order of rotary, pasture 1 and pasture 2. When the connection sensitivity PTO switch 202 is set to a rotary, the connection of the PTO clutch E becomes faster. Mainly used on working machines such as rotary tillers. 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. When the backup on / off switch 204 is turned on, the rotary tiller 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 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. The horizontal changeover switch 207 can perform horizontal control of a working machine such as a rotary tiller. 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 is always kept parallel to the tractor body T. And in inclination, it controls so that a rotary tiller 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 a mounting hole for a lift cylinder (not shown). 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). Then, when the auto accelerator switch 209 is turned on and the rotary tiller is raised, the engine speed is reduced to about 1700 rpm.
Although not shown in part in FIG. 5, operation information such as these switches and dials is input to the controllers 100a, 100b, 100c, etc. from various sensors (not shown).

  In the traveling device according to the present embodiment, the ratio between the rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61 (front wheel rotational speed / rear wheel rotational speed) is a preset reference. A value (design theoretical value) is provided. That is, an initial setting reference value (design theoretical value ratio between the rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61) is normally set at the time of factory shipment. This reference value is stored in the memory 100d of the controller 100a, and when the 4WD / 2WD changeover switch 185 is in the 2WD state, the drive shaft rotational speed sensors (FIG. 5) 112a, 112b from this reference value or its vicinity. When the ratio between the rotational speeds of the left and right rear wheels 63 and 63 detected by the above and the rotational speeds of the left and right front wheels 61 and 61 deviates (specifically, when the reference value ± B (B> 0) is exceeded) ) Is automatically switched from the two-wheel drive state to the 4WD state by the controller 100a. The detection of the rotational speed by the drive shaft rotational speed sensors (FIG. 5) 112a and 112b is the average value of the rotational speeds of the rear differential shaft 10 and the front differential shaft 12, or the front and rear wheels 61 and 63, respectively.

When a work vehicle such as a tractor travels, a slip is likely to occur depending on the field conditions (for example, undulation of the field surface, softness, etc.). In particular, slipping occurs remarkably in soft fields and wet fields. When the wheels 61 and 63 slip, the ratio between the rotational speeds of the rear wheels 63 and 63 and the rotational speeds of the front wheels 61 and 61 deviates from the set reference value, so that it is automatically switched from 2WD to 4WD.
However, if there is wheel wear or the like, the ratio between the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61 may deviate from the set reference value even if slip does not occur. Therefore, when there is wear of the wheels, etc., it becomes easy to switch to 4WD regardless of slip, and even though 2WD is originally sufficient, it may become 4WD and further promote wear.

  In the four-wheel drive state, the rotation speed of the front wheel 61 and the rotation speed of the rear wheel 63 are driven by the gear ratio of the gear in the transmission case 65, but the actual rotation of the front wheel 61 and the rotation of the rear wheel 63 are theoretically the same. It does not become the gear ratio, and a slight deviation occurs. This deviation is caused by slipping of the wheels (tires) 61 and 63, and the front wheel 61 and the rear wheel 63 are worn little by little. When the wear of the wheels of the work vehicle is promoted, the durability of the wheels and the vehicle itself is inferior. If possible, it is desirable that the safety during traveling is high.

Therefore, according to the present embodiment, the traveling loader automatically switches from the two-wheel drive to the four-wheel drive by the 4WD / 2WD changeover switch 185, and the rotational speed of the rear wheels 63 and 63 and the front wheel 61 when traveling at 2WD. , 61 is an update storage function unit that performs a process of updating and storing in the memory 100d when a predetermined requirement is satisfied even when the ratio of the rotational speed of 61 is deviated from the set reference value stored in the memory 100d or the vicinity thereof Thus, the ratio of the rotational speed deviating from the set reference value or the vicinity thereof is changed, updated and stored in the memory 100d as a new reference value.
When a new reference value is stored in the memory 100d, the ratio between the rotational speed of the rear wheels 63, 63 and the rotational speed of the front wheels 61, 61 is updated from the new reference value updated in the memory 100d or the vicinity thereof. When it comes off, it automatically switches from 2WD to 4WD.

  By adopting this configuration, when the ratio between the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61 deviates from the set reference value stored in advance in the memory 100d or the vicinity thereof, it is always 2WD to 4WD. Instead of switching to 2WD, the setting reference value is updated to prevent unnecessary switching by applying a fixed pawl, and switching from 2WD to 4WD only when it is necessary to truly enter the four-wheel drive state. it can.

In the above-described conventional example, the determination is made based on the difference in rotational speed between the left and right rear wheels 63, 63. When the rotational speed difference between the left and right rear wheels during two-wheel drive traveling exceeds a reference value. Although the two-wheel drive state is automatically switched to the four-wheel drive state, in this configuration, the determination is based on the ratio of the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61.
Accordingly, in the conventional example, if the left and right rear wheels 63 and 63 have the same degree of slip, the four-wheel drive state cannot be switched. However, in this configuration, one rear wheel 63 or one front wheel 61 slips. If the ratio between the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61 deviates from the reference value, the four-wheel drive state is switched. In an instantaneous situation, only one of the wheels 61 (63) may be worn, but the same thing occurs in the left and right wheels 61 (63) over a long period of time. Only (63) is not very worn.

In FIG. 5, only one drive shaft rotational speed sensor 112a, 112b is shown on each of the front wheels 61, 61 side and the rear wheels 63, 63 side. Then, the rotational speeds of the front and rear wheels 61 and 63 can be detected. And when calculating | requiring the rotation speed difference of the front wheel 61 and the rear wheel 63, it is good also as an average value of each right and left.
As a predetermined requirement for the function of the update storage function unit, for example, the rotational speed ratio deviating from the setting reference value or its vicinity is stable (setting reference value ± a) for a predetermined time (for example, about 5 minutes). If a> 0), the rotation speed ratio may be changed, updated, and stored in the memory 100d as a new reference value. Note that “stable” means a state in which the deviation in the rotational speed difference is always stable, and even if there is a slight deviation, it is excluded in a short time.

When the wheels 61 and 63 are worn or the like, unlike the case of slip, the ratio between the rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61 continues stably. Therefore, if the ratio of the rotational speed that has been stably continued as a new reference value, as in this configuration, is switched from 2WD to 4WD when the stored reference value or the vicinity thereof is deviated, 2WD is frequently used. Can be prevented from being switched to 4WD.
Therefore, the wheel 61, 63 is switched from 2WD to 4WD only when it is necessary to make it truly 4WD without promoting the wear of the wheels 61, 63, so that the durability of the wheels 61, 63 and the vehicle itself and the safety during traveling can be improved. improves.

Further, until the total traveling time of the tractor after factory shipment is a predetermined time (for example, about 10 hours), the rotational speed of the rear wheels 63, 63 is based on the initial set reference value stored in the memory 100d at the time of factory shipment. When the ratio between the front wheel 61 and the rotational speed of the front wheels 61 deviates from the initial set reference value or the vicinity thereof, the switching is performed from 2WD to 4WD. In the case of exceeding, the controller 100a may be configured to switch from 2WD to 4WD based on the new reference value updated and stored in the memory 100d.
Note that even if a new reference value is stored in the memory 100d by the update storage function unit, the initial setting reference value is not deleted, and the initial setting reference value is held as part of the memory 100d. The initial set reference value is used until the total running time of the tractor after shipment from the factory is about 10 hours, and thereafter, the reference value is changed as described above from the rotational speed ratio of the rear wheels 63, 63 and the front wheels 61, 61. To do. However, when the wheels (tires) 61 and 63 are new, the initial set reference value is used again.

When the tractor is shipped from the factory, wear of the wheels 61 and 63 is slight, so that there is no problem by controlling with a theoretical value that is a set reference value at the time of factory shipment. However, after that, since the reference value from 2WD to 4WD is replaced according to the rotational speed of the wheels 61, 63 that gradually change due to the wear of the wheels 61, 63, a new one suitable for the wear state of the wheels 61, 63 is obtained. The switching from 2WD to 4WD can be controlled with a simple reference value.
Further, a specified range (a set reference value ± a stored in the memory 100d at the time of shipment from the factory) based on a continuous rotation speed ratio of at least about 5 minutes or more during driving with 2WD. A> 0), and the ratio of the rotational speed of the front wheels 61 and 61 to the rotational speed of the rear wheels 63 and 63 (also referred to as the front-rear wheel rotational ratio) continues stably (the rotational speed difference). It is preferable to average only the values within the specified range and replace them with new reference values without shifting back to the reference value.

When the slip and overrun of the tractor wheels 61 and 63 (which is the reverse of the slip, which is to travel a large distance with less rotation than the specified rotation), a new reference value is taken into account. Although it becomes an erroneous reference value, only a value within a specified range when continuously running at 2WD in a normal state in which no wheel slip or overrun occurs is used as a new reference value. Thus, it is possible to increase the accuracy of the reference value and prevent an erroneous reference value.
Also, if the load factor of the engine 62 is larger than specified even during driving at 2WD, for example, when the actual engine speed is lower than the set engine speed, a heavy load (such as stone or The ratio of the rotational speed of the front wheels 61 and 61 to the rotational speed of the rear wheels 63 and 63 at this time is not taken into consideration in the new reference value. The load factor of the engine 62 is calculated mainly from the engine speed detected by the engine rotation sensor 165 (FIG. 5), the exhaust temperature detected by the engine exhaust temperature sensor 164, and the like.

  When the load factor of the engine 62 is large, it can be predicted that a load is applied to the traveling device of the tractor, and the value at this time (ratio of the rotational speed of the front wheels 61 and 61 to the rotational speed of the rear wheels 63 and 63). If is added to the new reference value, there is a possibility of an incorrect reference value. Therefore, when the load factor of the engine 62 is large, it is possible to prevent an erroneous reference value from being obtained by eliminating the value at this time and increasing the accuracy of the reference value.

Further, when the working machine such as a rotary tillage device is being lowered or when the PTO is turned on by the PTO on / off switch 187 and the working machine is operating while driving at 2WD, the value at this time (front wheels 61, 61 The ratio of the number of revolutions of the rear wheel 63 and the number of revolutions of the rear wheels 63 is not added to the new reference value.
Compared to other cases (when the work equipment is in the raised state, or when the PTO is turned off) when the work equipment is being lowered or during work where the work equipment is in operation. Unlike the case where the tractor is running continuously under normal conditions (which means that the work equipment is lifted and the work equipment is not driven) because the load is applied to the tractor itself, the abnormal value must be taken into account. Therefore, by eliminating the value at this time and increasing the accuracy of the reference value, it is possible to prevent an erroneous reference value from being obtained.

Then, the ratio of the rotational speeds of the front wheels 61 and 61 and the rotational speeds of the rear wheels 63 and 63 during driving traveling with 2WD is collected as data, and a plurality of data is taken in, stored in the memory 100d, and stored. When a predetermined time (for example, about 5 minutes) elapses from the start of the collection, an average value of a plurality of acquired data is obtained, and the average value is stored and stored in the memory 100d as a new reference value candidate.
Further, when a predetermined time (for example, 1 hour) or more has elapsed since the start of data collection, the current rotational speed of the front wheels 61 and 61 and the rotational speed of the rear wheels 63 and 63 are selected from the collected and stored data. The data closest to the ratio may be updated and stored in the memory 100d as a new reference value. This is because the number of data increases by collecting data for a predetermined time, and the accuracy of data improves as the number of data increases.

By adopting this configuration, the ratio of the rotation speed of the front wheels 61 and 61 and the rotation speed of the rear wheels 63 and 63 that continue for at least about 5 minutes or more while driving at 2WD is adopted as data. Reliability can be increased. Further, after a predetermined time (for example, 1 hour) has elapsed since the start of data collection, the current rotational speed of the front wheels 61 and 61 and the rotational speed of the rear wheels 63 and 63 in the collected and stored data. By adopting data that is closest to the ratio, it is possible to improve the reliability of the data and prevent an erroneous reference value.
Further, from the collected and stored data, data closest to the current ratio of the rotational speed of the front wheels 61 and 61 to the rotational speed of the rear wheels 63 and 63 is updated and stored in the memory 100d as a new reference value. Thus, the safety during traveling is maintained by preventing a sudden change in the reference value and gradually changing the reference value. This is because if the reference value changes frequently, the transition timing from 2WD to 4WD will change frequently, so that stable running may not be possible.

FIG. 10 shows a flow of the above-described control example by the controller of the tractor of FIG.
First, when work by the tractor is started, reading of each sensor and switches is performed by the controller 100a. Then, if the 4WD / 2WD changeover switch 185 is in the traveling loader position, which is normally two-wheel drive but automatically switches to four-wheel drive, the routine proceeds to step B. The travel loader position is a setting that automatically switches from two-wheel drive to four-wheel drive as described above, and corresponds to “front wheel drive is set to auto 4WD (automatic four-wheel drive)” in step A.

In step B, the total running time (hour meter) of the tractor after factory shipment is measured with a timer (not shown). At the time of initial traveling, the total traveling time of the tractor immediately after shipment from the factory is still less than 10 hours. Therefore, the process proceeds to Step Y, and a reference for the ratio between the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61 is performed. The value is held (set) as an initial set reference value (initial reference data) stored in the memory 100d at the time of shipment from the factory.
This holding (setting) does not mean that the reference value is stored in the memory 100d, but means setting (holding) for use as reference data for comparison with the actual measurement value in step G later.

Then, when proceeding to Step C, when the current traveling state is detected by the drive shaft rotational speed sensors 112a, 112b and the vehicle is traveling at 2WD, the process proceeds to Step D, and the load factor of the engine 62 is measured.
The load factor of the engine 62 is calculated mainly from the engine speed detected by the engine rotation sensor 165 (FIG. 5), the exhaust temperature detected by the engine exhaust temperature sensor 164, and the like. If the load factor of the engine 62 is within the specified range, the process proceeds to step E.

  In step E, the position of the work implement is detected based on the arm position information from the lift arm sensor 161. If the work implement is in the raised state, the process proceeds to step F, and the on / off state of the PTO on / off switch 187 is confirmed. When the PTO on / off switch 187 is turned off and the PTO shaft 14 is not rotating (during non-rotating), the drive shaft rotation speed sensors (FIG. 5) 112a and 112b cause the current left and right rear wheels 63, The number of rotations 63 and the number of rotations of the left and right front wheels 61, 61 are detected and taken in as data (step T).

  Then, the process proceeds to step G, where the initial reference data (initial setting reference) in which the ratio of the rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61 captured at this time is set in the previous step Y. Value), the set reference data is stored and saved in the memory 100d. Note that a plurality of rotation speed ratios of the left and right rear wheels 63 and 63 and the rotation speed ratio of the left and right front wheels 61 and 61 are captured. If the rotation speed ratio is not within the reference value ± a, the captured reference data is discarded. Is done.

Next, in Step H, whether or not five minutes or more have elapsed since the current ratio of the rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61 have been taken in (from the start of data collection). If more than 5 minutes have elapsed, a plurality of rotation speed ratios stored and stored in the memory 100d are averaged to obtain a ratio between the rotation speeds of the left and right rear wheels 63 and 63 and the rotation speeds of the left and right front wheels 61 and 61. And stored in the memory 100d as reference value candidates (step Z).
Note that the reference data discarded because the rotation speed ratio is not within the reference value ± a proceeds to No in step H.

  Further, in step I, when data collection of the ratio of the rotational speed of the left and right rear wheels 63 and 63 and the rotational speed of the left and right front wheels 61 and 61 is started, that is, when one hour or more has elapsed from step T, step Z The reference value candidate data that is the closest to the initial reference data becomes a new reference value by comparing the plurality of reference value candidate data stored and stored in the memory 100d with the initial reference data set in step Y Is updated and stored in the memory 100d (step W).

  And it progresses to step J, the present driving state is confirmed again, and when driving | running | working driving | running | working by 2WD, it progresses to step K. In step K, the current rotational speeds of the left and right rear wheels 63 and 63 and the rotational speeds of the left and right front wheels 61 and 61 are detected again by the drive shaft rotational speed sensors (FIG. 5) 112a and 112b. If the ratio is within the reference value (detection reference data updated and stored in the memory 100d in step W) ± B, the vehicle continues traveling at 2WD, and the reference value (detection reference data updated and stored in the memory 100d in step W). ) If not within ± B (B> 0), switch to 4WD.

Once the reference value candidate data is updated and stored in the memory 100d in this way (step W), if the total travel time after the factory shipment of the tractor is 10 hours or more, the process proceeds from step B to step X. The reference value of the ratio between the rotation speed of the rear wheels 63 and 63 and the rotation speed of the front wheels 61 and 61 is updated and stored (set) as a new reference value (detection reference data) stored in step W.
On the other hand, if the total travel time after the factory shipment of the tractor is less than 10 hours, the process proceeds from step B to step Y, and the reference value of the ratio between the rotational speed of the rear wheels 63 and 63 and the rotational speed of the front wheels 61 and 61 is set. It is held (set) as an initial set reference value (initial reference data) stored in the memory 100d at the time of shipment from the factory.

  Then, when the process proceeds from step X and step Y to step C, the same process as the flow described above is followed. However, when the process proceeds from step B to step X, the “reference value” in step G is changed to step X. It becomes the reference data (reference value) set in. Therefore, the ratio of the rotational speeds of the left and right rear wheels 63, 63 taken in step T and the rotational speeds of the left and right front wheels 61, 61 is compared with the reference data (reference value) set in step X by the reference value ±. If it is within a, the set reference data is stored and saved in the memory 100d (step G).

Thus, the reference value of the rotation speed ratio between the rotation speeds of the left and right rear wheels 63 and 63 and the rotation speeds of the left and right front wheels 61 and 61 can be updated and stored to an appropriate reference value corresponding to the total travel time. The switching from 2WD to 4WD suitable for the wear state of the wheels 61 and 63 can be controlled on the basis of the newly updated and stored reference value. Therefore, the wheel 61, 63 is switched from 2WD to 4WD only when it is necessary to make it truly 4WD without promoting the wear of the wheels 61, 63, so that the durability of the wheels 61, 63 and the vehicle itself and the safety during traveling can be improved. improves.
Furthermore, since the rotation speed ratio to be taken into consideration as the reference value is determined according to the load factor of the engine 62 and the state of the work implement, the accuracy of the reference value can be increased and the reliability of the reference value can be increased.

FIG. 11 shows a display example of the display unit of the meter panel of the tractor shown in FIG.
By the way, in work by a work vehicle such as a tractor, a plurality of operators often use one tractor in turn. However, the fuel consumption of the engine 62 of each operator varies depending on individual differences such as work contents and operators. It is desirable to keep the fuel consumption of the engine 62 as small as possible.

  Therefore, in order to know the fuel consumption of the engine 62 for each operator, the fuel consumption of the engine 62 for each operator is displayed on the display unit 215 (FIGS. 5 and 7) of the meter panel 213 (FIGS. 5 and 7) of the tractor. Display it in a table or graph. For example, as shown in FIG. 11, when there are five operators (A to E) in total, as shown in FIG. It is obvious at a glance which operator is using how much. Further, since the fuel consumption varies depending on the amount of work, if the average fuel consumption per unit time is displayed, it becomes easier to compare each operator. The graph display may be, for example, a pie chart or a bar graph, and the shape and color may be changed depending on the operator and the amount of fuel consumption.

At the time of operator change, at the start of work, etc., each person's data is connected to this machine by an external input device of the tractor (for example, a portable input device etc.) to perform operator information, sensor check, etc. 180 may be provided with such a function) and registered, the controller 100b can be identified. Then, the fuel consumption for each operator is detected by a flow sensor (not shown) provided on the upstream side of the high-pressure injector 170 (FIG. 5), and the detected fuel consumption is displayed on the display unit 215.
When a single tractor is used by a plurality of operators, the fuel consumption amount of the engine 62 is displayed for each operator, thereby clarifying the operator whose driving operation should be improved. Therefore, it can be expected that an operator with a large amount of fuel consumption is aware and urged to suppress the fuel consumption amount, which leads to energy saving.

FIG. 12 shows another display example of the display unit of the meter panel of the tractor of FIG.
In order to recognize the operator, if the respective data is registered in the memory 100d of the controller 100b of the tractor in advance, the operator uses his / her name or number (including symbols) registered at the time of operation. Thus, when the tractor is used, it can be confirmed or designated on the display unit 215.

For example, as shown in FIG. 12, the names of all operators are displayed on the display unit 215 at the start of use of the tractor. There is a display of driving on the right side of each operator. When the operator who selects the driving display on the right side of his / her name (for example, touches) and presses and holds the display changeover switch 217, the controller 100b Recognize who you are. For example, when the operator A uses it, when the operator A touches the operation display on the right side of the operator A and presses and holds the display changeover switch 217, the controller 100b recognizes that the operator is A.
As described above, since each controller can be easily recognized by the controller 100b, it is possible to save the operator's input operation and to improve the operability without burdening the operator.

FIG. 13 shows a perspective view of a reading device for recognizing an operator.
A reading device 220 for recognizing the operator is provided at an arbitrary position of the tractor in FIG. 1 (the range in which the operator can sit and operate on the seat of the cockpit 16), and the operator is recognized from the identification information read by the reading device 220. You may make it do.

  The reading device 220 can read, for example, a card or a wireless tag. As shown in FIG. 13, the operator has a card 221 to which his / her data is input, and inserts the card 221 into the reading device 220. When inserted into the reading device 220 from the port 220a, data (operator information) input to the card 221 is transmitted to the controller 100b. When the controller 100b recognizes who the operator is, although not shown, if the operator's name and face photo are displayed on the display unit 215, the operator confirming it can.

  The operator can easily and accurately recognize each operator by simply inserting his / her own card 221 into the reading device 220, so that the operability is good without burdening the operator. In addition, there is a possibility of an erroneous operation when the operator inputs, but it is possible to prevent an erroneous operation by using the card 221 to which the respective data is input.

FIG. 14 shows an example in which an operator recognition switch is provided on the meter panel 213 of the tractor shown in FIG.
Further, as shown in FIG. 14, switches 231 to 236 having numbers assigned to the respective operators are provided at arbitrary locations, and when the operator presses the switches 231 to 236 having their own numbers at the start of use of the tractor, the controller 100b It may be made to recognize who the operator is.

By entering and registering operator information corresponding to each switch 231 to 236 in advance, each operator can easily and accurately identify the operator by simply pressing the switch 231 to 236 of his / her number at the start of use of the tractor. Become able to recognize.
When the operator's name, symbol, or the like is displayed on the display unit 215 as shown in FIG. 12 or the like, the screen may need to be switched during operation or the screen may be switched during work. In the case of 236, it is provided in an arbitrary place in advance, and if it is turned on when pressed, its own number can be confirmed at all times. In addition, since the operator only has to press his / her switches 231 to 236 at the start of work, the operability is good without burdening the operator.

If the operator cannot be identified by the controller 100b, the engine 62 can be controlled so that the engine 62 cannot be started by stopping the output signals to the pump 169, the high pressure injector 170, etc. in FIG. Also good.
In this way, by preventing the engine 62 from starting, it is possible to prevent the operator from forgetting to enter data. In addition, it is possible to ensure that there is no mistake in the recognition of the operator who originally works. Furthermore, it is possible to prevent an unrelated person other than the operator from working without permission.

15A is a perspective view showing another example of the auxiliary transmission lever 179 (FIGS. 6 and 7) of the tractor of FIG. 1, and FIG. 15B is a perspective view of FIG. 15A. A rear view of the auxiliary transmission lever 179 is shown, and FIG. 15C is a longitudinal sectional view taken along line S-S in FIG.
The sub-transmission lever 179 shown in FIG. 15 is different in shape from the sub-transmission lever 179 shown in FIGS. 6, 7, etc., and the main transmission acceleration / deceleration operation switch 192a is attached to the grip portion (grip) 179g of the sub-transmission lever 179. , 192b.

  As described above, by providing the main shift increase / decrease operation switches 192a and 192b in the grip portion 179g of the sub shift lever 179, the main shift increase / decrease operation switches 192a and 192b can be operated simultaneously while operating the sub shift lever 179. However, since the main transmission speed increase / decrease operation switches 192a and 192b can be operated simultaneously with the operation of the auxiliary speed change lever 179, the operability is excellent. On the other hand, since the finger easily touches the main speed increase / decrease operation switches 192a and 192b, When holding it, it may be operated incorrectly.

Therefore, it is preferable that the upper surface portion of the grip 179g of the auxiliary transmission lever 179 has a concave shape, and the main speed increase / decrease operation switches 192a and 192b are provided in the concave shape portion U.
As shown in FIG. 15 (c), the main speed increasing / decreasing operation switches 192 a and 192 b are provided at positions lower than the height position U 1 of the edge of the concave shape portion U, or the bottom surface U 2 of the concave shape portion U and Provide at the matching position. By providing a gap V so that the main transmission speed increase / decrease operation switches 192a, 192b do not protrude from the upper surface of the concave shape portion U, the main speed increase / decrease operation switch can be easily operated even if the operator grasps the grip 179g of the auxiliary speed change lever 179. Hands and fingers do not touch 192a and 192b.
In addition, since the operator touches the concave portion U of the grip 179g when the sub-shift lever 179 is gripped, the positions of the main gear speed increase / decrease operation switches 192a and 192b are easy to understand and can be operated without looking at the hand, thus preventing erroneous operation. The operability of the auxiliary transmission lever 179 and the main transmission increase / decrease operation switches 192a and 192b is also improved. Further, the auxiliary transmission lever 179 and the main transmission increase / decrease operation switches 192a and 192b are easy to use.

  By adopting this configuration, the main shift increase / decrease operation switches 192a, 192b are mistakenly lost without losing the good operability that the main shift increase / decrease operation switches 192a, 192b can be operated simultaneously with the operation of the auxiliary transmission lever 179. It is possible to prevent an erroneous operation of operating the tractor and improve the safety of the tractor during traveling.

FIG. 16 is a perspective view showing another example of the auxiliary transmission lever 179 of FIG.
The auxiliary transmission lever 179 shown in FIG. 16 is provided with a movable fulcrum Y below the grip 179g of the auxiliary transmission lever 179 of FIG. 15, and the grip 179g of the auxiliary transmission lever 179 moves obliquely upward in the direction of arrow M. And there are a variety of ways to grip and switch operations.

Depending on the shape of the grip 179g of the auxiliary transmission lever 179, how to grip the grip 179g and the switch operation of the main transmission increase / decrease operation switches 192a, 192b are limited. By adopting this configuration, the grip 179g of the auxiliary transmission lever 179 is used. Since it is possible to operate the switch by grasping from a plurality of directions, the operability is improved.
For example, as shown in FIG. 16, the auxiliary transmission lever 179 is provided on the right side of the seat of the cockpit 16 and is operated with the right hand. However, when the auxiliary transmission lever 179 is grasped from above, the middle finger 240 or other fingers are used. The main shift increase / decrease operation switches 192a and 192b can be easily operated. In addition, when the grip 179g is gripped from the left and right directions, the main shift increase / decrease operation switches 192a and 192b can be easily operated with the thumb 241.
As described above, the grip 179g of the auxiliary transmission lever 179 is movable in the oblique direction, so that the operability is not hindered even when the auxiliary transmission lever 179 is gripped from the upper side or the left-right direction. Therefore, it can be gripped so that it can be easily operated by the operator, and the usability is improved and the operability is improved.

FIG. 17 is a perspective view showing another example of the auxiliary transmission lever 179 of FIG. 15, and an enlarged view of the hole portion is shown in the round frame portion.
Further, a plurality of small anti-slip holes 243 may be provided on the surface of the front portion 179i from the grip portion 179g to the base portion 179h of the auxiliary transmission lever 179 shown in FIG.
As shown in FIG. 17, a concave hole 243 is provided in the front portion 179 i of the auxiliary transmission lever 179 to make it difficult to slip when the auxiliary transmission lever 179 is gripped. The hole 243 may be resin-molded or mold-molded, and the material is not limited. For example, the hole 243 is formed by mold digging.

When the hole 243 is provided on the entire front surface 179i, the hand or finger can reliably touch the hole 243 regardless of whether the grip 179g of the auxiliary transmission lever 179 is gripped or the base 179h. Can be prevented from slipping.
The sub-transmission lever 179 of the conventional tractor is often subjected to a fine textured surface treatment as a surface treatment, and the textured portion is rubbed and slippery over time.
However, by adopting a mold digging that has a larger unevenness than the embossing treatment as in this configuration, it becomes difficult to slip when the auxiliary transmission lever 179 is gripped, and operability and safety are improved. The material of the front part 179i may be changed from that of the other part so that the sensation and feel when touched may be different from the convex part instead of the concave part.

18A is a perspective view showing another example of the auxiliary transmission lever 179 of FIG. 15, and FIG. 18B is a front view of the auxiliary transmission lever 179 of FIG. FIG. 18C shows an enlarged cross-sectional view of the hole 243.
The auxiliary transmission lever 179 shown in FIG. 17 has a plurality of small anti-slip holes 243 provided on the entire surface of the front part 179i, but the concave hole 243 is formed only on the surface of the front part 179i on the grip part 179g side. It may be provided.

  As shown in FIG. 17, if the hole 243 is provided on the entire front surface 179i, the hand or finger can surely touch the hole 243, so that it can be prevented from slipping during the operation, but as shown in FIG. If the hole 243 is provided only on the surface of the grip part 179g, the switch positions of the main transmission speed increase / decrease operation switches 192a and 192b can be grasped, which is easy to understand. Therefore, even if the hole 243 is provided in a part of the front part 179i, the operability of the main speed increase / decrease operation switches 192a and 192b is good, and only the part where the hole 243 is formed can be removed from the front part 179i. If it is possible to replace it, it is more economical than replacing the entire front portion 179i.

FIG. 19A is a perspective view showing another example of the auxiliary transmission lever 179 of FIG. 15, and FIG. 19B is a perspective view of the auxiliary transmission lever 179 of FIG. The perspective view showing the positional relationship of is shown.
As shown in FIGS. 17 and 18, the hole 243 may not be provided in the front portion 179 i, but a recess may be formed by the groove 244. As shown in FIG. 19, the groove 244 may be formed in the horizontal direction, or the groove 244 may be formed in the vertical direction. Further, the grooves 244 may be formed in an intersecting manner.

  The presence of the groove 244 in the front portion 179i makes it difficult to slip when the auxiliary transmission lever 179 is gripped, as in the case shown in FIGS. 17 and 18, and operability and safety are improved. In the illustrated example of FIG. 19, the groove 244 is provided only on the surface of the grip portion 179g of the front portion 179i, but it goes without saying that the groove 244 may be provided on the entire surface of the front portion 179i.

  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.

It is a left view of the tractor of one Embodiment of this invention. It is a power transmission diagram in the transmission of the tractor of FIG. FIG. 3 is a hydraulic circuit diagram of the power transmission diagram of FIG. 2. It is a block diagram of the hydraulic clutch cylinder for forward / reverse power on / off of the transmission of FIG. It is a control block diagram of the tractor of FIG. 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. 8A is a plan view of the switch box of FIGS. 6 and 7, and FIG. 8B is a side view. It is an enlarged view of a 4WD / 2WD switch. It is a flow of the example of control by the controller of the tractor of FIG. It is the figure which showed the example of a display of the display part of the meter panel of the tractor of FIG. It is the figure which showed another example of a display of the display part of the meter panel of the tractor of FIG. It is a perspective view of the reading device for recognizing an operator. It is the figure which showed the example which provided the switch for recognition of an operator in the meter panel of the tractor of FIG. 15 (a) is a perspective view showing another example of the auxiliary transmission lever of the tractor of FIG. 1, and FIG. 15 (b) is a rear view of the auxiliary transmission lever 179 of FIG. 15 (a). FIG. 15C is a longitudinal sectional view taken along the line S-S in FIG. FIG. 16 is a perspective view showing another example of the auxiliary transmission lever of FIG. 15. FIG. 16 is a perspective view showing another example of the auxiliary transmission lever of FIG. 15. 18 (a) is a perspective view showing another example of the auxiliary transmission lever of FIG. 15, FIG. 18 (b) is a front view of the auxiliary transmission lever of FIG. 18 (a), and FIG. c) is an enlarged sectional view of the hole. FIG. 19A is a perspective view showing another example of the auxiliary transmission lever of FIG. 15, and FIG. 19B is a perspective view showing the positional relationship between the auxiliary transmission lever and the finger of FIG. FIG.

Explanation of symbols

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 Pilot seat 18 PTO transmission shaft 19 Main transmission shaft 19 Main transmission 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 Gear 40 High / low speed switching gear 41 Front wheel drive switching gear 42 Forward / reverse switching gear 43 Back counter gear 44 PTO shift 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 73 Steering handle 76 Clutch packs 77F, 77R Return springs 78F, 78R Piston 80 Hydraulic pump 81a , 81b Pressure reducing valve 82a Brake valve 82b Pressure control valve 83 Brake cylinder 85 Forward / reverse clutch cylinder 86 Forward / reverse clutch proportional Force control valve (switching valve)
86F, 86R Solenoids 87, 88, 91, 92 Hydraulic clutch cylinder 89 Main shift (2-4) Clutch proportional pressure control valve 89a Shift 2-4 switching solenoid 89b Shift 2-4 boost solenoid 90 Forward / reverse boost solenoid 93 Main shift ( 1-3) Clutch proportional pressure control valve 93a 1-3 speed switching solenoid 93b 1-3 speed boosting solenoid 94 switching control valve 95 High / low hydraulic clutch cylinders 96a, 96b Control valve (solenoid)
97 Differential lock control valve 98a Front wheel differential lock cylinder 98b Rear wheel differential lock cylinder 99 4WD switching clutch cylinders 100a to 100c Control processing device (controller)
100d memory 101 main hydraulic circuit 103 power steering device 104 PTO clutch cylinders 105, 106 PTO clutch proportional pressure control valve 107 orbit roll 110 forward clutch pressure sensor 111 reverse clutch pressure sensor 112a front wheel drive shaft rotational speed sensor 112b rear wheel drive shaft Rotational speed sensor 113 High clutch pressure sensor 114 Low clutch pressure sensor 115 Forward / reverse switching lever 115a Forward / reverse lever sensor 116 Front wheel break angle sensor 119 Clutch pedal 119a Clutch pedal sensor 121 Front wheel acceleration 4WD solenoid 122 Front wheel constant velocity 4WD solenoid 129 On OFF control valve 129a Clutch solenoid 130, 131, 133-137, 139, 140 Gear 145, 146 Pressure sensor 147 Mission Ile oil temperature sensor 153 Accelerator fine adjustment lever 161 Lift arm sensor 164 Engine exhaust temperature sensor 165 Engine rotation sensor 166 Engine oil pressure sensor 167 Engine water temperature sensor 168 Rail pressure sensor 169 Fuel high pressure pump 170 High pressure injectors 171a and 171b Lifting and lowering solenoids 172 Parking brake 173 PTO change lever 175 Accelerator pedal 175a Accelerator position sensor 176 Accelerator lever 177a, 177b Engine speed memory switch 178a, 178b Sub-control lever 179 Sub-transmission lever 179a Lever guide 179b Sub-transmission path upper speed position 179c Sub-transmission high speed position 179d Sub Medium speed position 179e Sub gear low speed position 179f Sub gear lever operating position sensor 179g Minute 179h Base 179i Front 180 Switch box 181 Operation panel 182 Draft ratio adjustment dial 183 Raise adjustment dial 184 Tilt adjustment dial 185 4WD / 2WD changeover switch 186 Manual raise / lower switch 187 PTO on / off switch 188 PTO manual automatic switch 189 Differential lock switch 190 Working machine Position lever 191 Elevating switch (work machine elevating switch)
192a, 192b Main shift increase / decrease 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 211 Lid 213 Meter panel 215 Display unit 217 Display selector switch 220 Reading device 220a Insert port 221 Cards 231 to 236 Switch 240 Middle finger 241 Thumb 243 Hole 244 Groove A Main transmission hydraulic clutch B C Lo shifting clutch C subtransmission gear transmission mechanism D forward-reverse clutch E PTO clutch T tractor body U grip upper surface (concave shaped portion)
V gap

Claims (2)

Front wheel (61) and rear wheel (63);
A driving state in which the driving state is automatically switched according to the road surface state between a two-wheel driving state in which the rear wheel (63) is driven and a four-wheel driving state in which the rear wheel (63) and the front wheel (61) are driven. Drive state setting means (185) that can be set to a plurality of modes including an automatic switching mode;
A rotational speed detection means (112a, 112b) for detecting the rotational speed of the rear wheel (63) and the rotational speed of the front wheel (61), respectively;
A storage unit (100d) for storing a reference value that is a preset rotation speed ratio (front wheel rotation speed / rear wheel rotation speed) of the rear wheel (63) and the front wheel (61); When the driving state automatic switching mode is set by the setting means (185), a switching process between the two-wheel driving state and the four-wheel driving state corresponding to the road surface state is performed, and the vehicle is running in the two-wheel driving state. When the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detection means (112a, 112b) sometimes deviates from the reference value stored in the storage unit (100d) or the vicinity thereof Is a traveling device for a work vehicle provided with a control device (100a) for performing a process of switching from a two-wheel drive state to a four-wheel drive state,
The control device (100a) is detected by the rotational speed detection means (112a, 112b) when the drive state automatic switching mode is set by the drive state setting means (185) and the vehicle is running in a two-wheel drive state. When the rotational speed ratio between the rear wheel (63) and the front wheel (61) thus deviated from the reference value stored in the storage unit (100d) or its vicinity, the rotational speed ratio deviated from the reference value or its vicinity Is provided with an update storage function unit for performing processing for updating the reference value or the rotation speed ratio deviating from the vicinity thereof as a new reference value and storing it in the storage unit (100d), After the storage by the update storage function unit, the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detection means (112a, 112b) is stored in the storage unit (100 ) To update the stored new reference value or running device for a working vehicle and performs the processing for switching deviates from the vicinity of the two-wheel drive state to the four-wheel drive state. Front wheel (61) and rear wheel (63);
A driving state in which the driving state is automatically switched according to the road surface state between a two-wheel driving state in which the rear wheel (63) is driven and a four-wheel driving state in which the rear wheel (63) and the front wheel (61) are driven. Drive state setting means (185) that can be set to a plurality of modes including an automatic switching mode;
A rotational speed detection means (112a, 112b) for detecting the rotational speed of the rear wheel (63) and the rotational speed of the (61), respectively;
A storage unit (100d) for storing a reference value that is a preset rotation speed ratio (front wheel rotation speed / rear wheel rotation speed) of the rear wheel (63) and the front wheel (61); When the driving state automatic switching mode is set by the setting means (185), a switching process between the two-wheel driving state and the four-wheel driving state corresponding to the road surface state is performed, and the vehicle is running in the two-wheel driving state. When the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detection means (112a, 112b) sometimes deviates from the reference value stored in the storage unit (100d) or the vicinity thereof Is a traveling device for a work vehicle provided with a control device (100a) for performing a process of switching from a two-wheel drive state to a four-wheel drive state,
The control device (100a) is detected by the rotational speed detection means (112a, 112b) when the drive state automatic switching mode is set by the drive state setting means (185) and the vehicle is running in a two-wheel drive state. When the rotational speed ratio between the rear wheel (63) and the front wheel (61) thus deviated from the reference value stored in the storage unit (100d) or its vicinity, the rotational speed ratio deviated from the reference value or its vicinity Is provided with an update storage function unit for performing processing for updating the reference value or the rotation speed ratio deviating from the vicinity thereof as a new reference value and storing it in the storage unit (100d),
After the storage by the update storage function unit, when the total traveling time of the work vehicle is less than a predetermined time, the rotation speed detection means based on a reference value that is preset and stored in the storage unit (100d) When the ratio of the rotational speed of the rear wheel (63) and the rotational speed of the front wheel (61) detected by (112a, 112b) deviates from the reference value stored in the storage unit (100d) or the vicinity thereof, the two wheels While the process of switching from the driving state to the four-wheel driving state is performed, if the total traveling time of the work vehicle is equal to or longer than a predetermined time, the updated storage function unit updates the new reference value stored in the storage unit (100d). As a reference, the rotational speed ratio between the rear wheel (63) and the front wheel (61) detected by the rotational speed detection means (112a, 112b) is updated and stored in the storage unit (100d) or in the vicinity thereof. From Running device for a working vehicle and performs the processing for switching from two-wheel drive state to the four-wheel drive state when.

Images