JP5526752B2 - Work vehicle transmission - Google Patents

Description

  The present invention relates to a transmission for a work vehicle provided with a multi-stage transmission mechanism used in a work vehicle such as a tractor.

  As described in Japanese Patent Application Laid-Open No. 2005-163814, the work vehicle transmission (transmission) travels on the road by shifting the rotation of the engine rotating at a substantially constant rotation to a desired traveling speed by a multi-stage transmission mechanism. In order to simplify the speed change operation, the speed change mechanism is automatically shifted to a plurality of stages only by operating the accelerator pedal.

JP 2005-163814 A

  The conventional transmission control device includes a main transmission device that can change gears in multiple stages and an auxiliary transmission device that can change gears in at least two steps. When the auxiliary transmission device is switched to a shift position suitable for traveling on the road, an accelerator pedal is used. Thus, the shift stage of the main transmission is automatically performed, and the shift operation of the main transmission during traveling on the road is unnecessary. With this shift control device, when traveling on the road with the work implement removed, a comfortable acceleration feeling can be obtained, but when traveling on the road with a heavy work implement attached, torque is required for the main shift shift with the accelerator pedal. In order to be insufficient, the main shift must be manually changed.

  In view of the above, an object of the present invention is to ensure that the automatic transmission of the main transmission by the accelerator pedal is appropriately performed during traveling on the road regardless of whether the work implement is attached or detached.

The problems of the present invention are solved by the following technical means.
According to the first aspect of the present invention, in a transmission for a work vehicle in which a transmission clutch device B, a switching clutch C, and a sub-transmission device D are provided in a transmission case, the transmission clutch device B and the switching clutch C can be automatically shifted. And is provided with a sub-shift detection means 147 for detecting the shift position of the sub-transmission device D. When the sub-shift detection means 147 detects a road traveling shift position, the operation of the accelerator pedal 173 and the shift clutch device B The shift of the switching clutch C is configured to be automatically controlled at a plurality of speeds, and a plurality of speed ranges H1 and H2 are provided in the speed ratio of the combination of the speed change clutch device B and the switching clutch C. H2 can be selected as appropriate ,
A travel shift increase switch 193 and a travel shift decrease switch 194 for setting start shift speeds of the plurality of shift ranges H1 and H2, and a switch for changing and setting the maximum shift speed of the plurality of shift ranges H1 and H2,
A sub-shift lever 178 for performing a shift operation of the sub-transmission device D is provided, and an accelerator shift setting switch 160 for selecting a plurality of shift ranges H1, H2 is provided on the sub-shift lever 178, so that the plurality of shift ranges H1, H2 are set. Configure to be selectable,
After the change of the plurality of shift ranges H1 and H2 is set by the accelerator shift setting switch 160, the automatic shift control by the accelerator pedal is canceled or the automatic shift control by the accelerator pedal is executed again after the engine is stopped. It is configured to change to the set shift range,
When the auxiliary transmission lever 178 is on the road traveling position, a clutch button 162 capable of changing the plurality of transmission ranges H1 and H2 is provided .

According to a second aspect of the present invention , the starting shift stage is shifted up or down every time the travel shift increase switch 193 or the travel shift decrease switch 194 is pressed once. It is set as the transmission apparatus of the working vehicle as described in above.

The effects of claims 1 and 2 will be described below.

According to the first aspect of the present invention, when the sub-transmission detecting means 147 detects that the sub-transmission device D is set to the shift position for traveling on the road, the shift stages of the transmission clutch device B and the switching clutch C are only operated by the accelerator pedal 173. It becomes possible to travel at a desired speed by changing the. Then, by changing the shift range according to the situation of the work vehicle, it is possible to travel efficiently. For example, when a load is loaded or a work machine is mounted to increase the weight of the work vehicle, the speed is changed to a shift range H1 having a large output torque, so that a comfortable acceleration feeling can be obtained and driving is facilitated.
The travel shift up switch 193 and travel shift down switch 194 for setting the starting shift speeds of the plurality of shift ranges H1 and H2 are provided, and the switch for changing and setting the maximum shift speed of the plurality of shift ranges H1 and H2 is provided. Setting is easy.
A sub-shift lever 178 for performing a shift operation of the sub-transmission device D is provided, and an accelerator shift setting switch 160 for selecting a plurality of shift ranges H1, H2 is provided on the sub-shift lever 178 to select a plurality of shift ranges H1, H2. Since it is configured to be possible, change setting becomes easy.
After changing the multiple speed ranges H1 and H2 with the accelerator shift setting switch 160, cancel the automatic shift control with the accelerator pedal, or execute the automatic shift control with the accelerator pedal again after the engine is stopped, set immediately before Therefore, it is not necessary to set again.
Since the clutch button 162 capable of changing the plurality of shift ranges H1 and H2 is provided when the sub-shift lever 178 is at the road travel position, the plurality of shift ranges H1 are obtained only by operating the clutch button 162 at the road travel position. , H2 can be changed.

In the configuration of claim 2, in addition to the effect of claim 1, each time the travel shift increase switch 193 or the travel shift decrease switch 194 is pressed once, the starting shift stage can be shifted up or down, so that the operability is improved. good.

It is a side view of a tractor. It is a cabin internal perspective view of a tractor. It is a front view inside the switch box of a tractor. It is a front view of a meter panel. It is a shift pattern diagram of 24-speed shift. It is a shift pattern figure of 32 step shifting. It is a transmission diagram of a mission case with constant PTO shaft rotation including reverse rotation. It is a transmission diagram of a transmission case of a type in which PTO shaft rotation corresponds to a vehicle speed. FIG. 5 is a partial cross-sectional view of a transmission case of a type in which PTO shaft rotation corresponds to a vehicle speed. It is a partial cross section figure of a mission case with constant PTO shaft rotation including reverse rotation. It is a partial cross section figure of a mission case. It is a control block diagram.

Hereinafter, description will be given based on the drawings.
FIG. 1 is an overall side view of a tractor shown as an example of a work vehicle according to the present invention. The power of a common rail type diesel engine 2 mounted in a bonnet 1 at the front of the body is used to transmit PTO shaft rotation constant mission case 3A (first stage). 1 transmission case) or a PTO shaft rotating vehicle speed compatible transmission case 3B (second transmission case), and the gear is appropriately shifted and transmitted to the front wheel shaft 4 and the rear wheel shaft 5, and both the front wheel 6 and the rear wheel 7 or the rear Only the wheel 7 is driven. An operator sitting in a seat 10 provided in a cabin 26 on the airframe travels while operating the steering handle 8 standing at the center to steer the front wheels 6. A work machine such as a rotary tiller is mounted on the hitch 9 protruding rearward of the machine body, and the work machine mounted on the hitch 9 is driven by the PTO shaft 11 protruding rearward from the transmission case 3A (3B). .

  As shown in FIGS. 2 and 3, a steering handle 8 is erected on the front side of the cockpit 10 inside the cabin 26, and a forward / reverse lever 169 is provided on the lower right side thereof. On the left side of the cockpit 10, a parking brake lever 170 and a first PTO transmission lever 171 and a second PTO transmission lever 172 for shifting the PTO shaft that outputs power to the work machine are arranged.

  The lower floor surface of the steering handle 8 is provided with a left brake pedal 216 and a right brake pedal 217 for braking the left and right front and rear wheels 6 and 7, respectively, and an entire brake pedal 218 for braking all the wheels at once. An accelerator pedal 173 that controls the rotation of the engine 2 is provided. This accelerator pedal 173 is used to adjust the traveling speed.

  Note that when the left brake pedal 216 and the right brake pedal 217 are depressed simultaneously, the brake is braked, and the gear stage of the main transmission is shifted to the low speed side to cause the engine brake to act. Further, when the left brake pedal 216 and the right brake pedal 217 are depressed more than a predetermined limit depression amount, the rotational speed of the engine 2 is decreased. At this time, if the left brake pedal 216 and the right brake pedal 217 are depressed and restored, the rotation of the engine 2 is restored, and the power transmission to the front and rear wheels 6 and 7 and the power transmission to the PTO output shaft are restored. After that, release the brake.

  A front panel 174 on which a meter panel 136 (FIG. 4) for displaying a traveling speed and a gear position and an operation panel (not shown) for displaying a use status of a work machine are disposed on the front side of the steering handle 8.

  When a throttle lever 175 is erected on the right side of the cockpit 10 and is tilted forward from the foremost idling position, the rotation of the engine 2 increases. The throttle lever 175 is also used when setting the engine speed during operation. 176 is a seesaw-type first engine rotation storage switch. When the switch is tilted upward, the first stored rotational speed is obtained. When the switch is tilted downward, the second stored rotational speed is obtained. When the finger is released, the position returns to the neutral position.

  177 is a seesaw-type second engine rotation memory switch. When the switch is tilted upward, the rotational speed increases. When the switch is tilted downward, the rotational speed decreases, and the rotational speed when the switch is released is stored. The rotation speed of the engine 2 is set by turning the first engine rotation storage switch 176 upward or downward, and tilting the second engine rotation storage switch 177 upward or downward to increase or decrease the rotational speed. When 176 and 177 are released, the rotation speed at that time is stored as the set rotation speed of the first engine rotation storage switch 176.

  Next to the throttle lever 175, an auxiliary transmission lever 178 is erected. The sub-shift lever 178 has three speeds for low speed, high speed, and road travel (ultra-high speed), or four speed positions for low speed, medium speed, high speed, and road travel (ultra high speed). In the case of high speed, road driving (ultra-high speed), the sub-transmission device D (mechanical four-speed transmission clutch D) in a mission case 3A (3B), which will be described later in each stage, is driven at low speed, medium speed, high speed, road driving (super The main transmission devices B and C (the transmission clutch device B having a hydraulic four-speed transmission and the high / low hydraulic pressure switching clutch C) can be shifted to eight gears.

  Although not shown, the auxiliary transmission lever 178 is provided with an accelerator transmission setting switch 160 for changing the accelerator transmission pattern to a low transmission area H1 and a high transmission area H2, and an auxiliary transmission lever operation position sensor 147. Yes. The accelerator shift setting switch 160 is also used as a sync clutch button 162 for switching the sub-shift position between low speed, medium speed, high speed, and road travel (ultra-high speed). You may enable it to change to H1 and the high speed change area H2.

  FIG. 5 shows the shift pattern of the sub-shift three-speed shift, and FIG. 6 shows the shift pattern of the sub-shift four-speed shift. When the sub-shift lever 178 is on the road, the main transmissions B and C (four-speed transmission clutch unit B and high-low hydraulic switching clutch C) are automatically shifted according to the degree of depression of the accelerator pedal 173. Two types of shift patterns are prepared: a low shift range H1 and a high shift range H2.

  The shift pattern of the low shift range H1 and the high shift range H2 is changed by the accelerator shift setting switch 160. Once the shift pattern is set, after the accelerator control is canceled or the engine is stopped, and the accelerator control is performed again, the previous setting is performed. A shift pattern is obtained.

  The main transmissions B and C are constituted by a four-speed shift of the transmission clutch device B having a hydraulic four-speed shift and a two-speed shift of the high / low hydraulic pressure switching clutch C, and the total number of shift stages is eight. The vehicle speed according to the shift speeds is a total of 32 shift speeds in combination with the low speed, medium speed, high speed, and road driving (ultra-high speed) sub-shift 4-speed shift of the sub-shift lever 178.

  179 and 180 are sub-control levers for taking out external hydraulic pressure, and are used when hydraulic oil is supplied to a hydraulic cylinder or the like of the work machine. Reference numerals 181 and 182 denote mounting grooves for the spare hydraulic sub-control lever. 183 is a draft ratio adjustment dial, which turns to the left when turned to the position side, reduces the amount of change in the lift of the work equipment with respect to the load, reduces the tilling depth, and conversely turns to the right to become the draft side, The amount of change in the lifting / lowering of the work equipment increases, increasing the tillage depth.

Reference numeral 184 denotes a raising adjustment dial. When the dial is turned counterclockwise, the elevation height of the three-point link mechanism of the work machine becomes low.
Depending on the work machine, when it is raised to the highest level, it hits the tractor body, or when the work efficiency is better for continuing the work if it is not raised too much, this adjustment dial 184 is used for adjustment. Reference numeral 185 denotes a tilt adjustment dial. When the dial is turned to the left, the work implement is raised to the right, and conversely, when turned to the right, the work implement is lowered to the right.

  186 is a 4WD changeover switch, which has a traveling loader, front wheel accelerated turning, and 2WD turn positions. The traveling loader is usually 2WD traveling, and automatically switches to 4WD when becoming muddy, steep hills, or uneven roads. Even if the switch is made, the brake is applied, or the vehicle is stopped during operation, the state becomes 4WD. 2WD is a rear-wheel two-wheel drive, and 4WD is a front-and-rear four-wheel drive. In the front wheel acceleration turning, when turning at 4WD, the speed of the front wheel is increased to enable quick turning. In the 2WD turn, the front wheel drive is cut off in the 4WD turn and the rear wheel is turned on one side of the brake, allowing quick and smooth turn in a hard field.

  Reference numeral 187 denotes a horizontal cylinder raising / lowering switch, which can move the horizontal cylinder of the three-point link of the work implement, and is used for attaching / detaching the work implement. Reference numeral 188 denotes a PTO switch. When the switch is pushed and turned to the right, the PTO clutch is engaged. 189 is a PTO automatic switch. When turned to the left, it becomes manual, and when the PTO clutch is engaged, the PTO shaft always rotates. When turned to the right, it automatically turns and stops rotating when the travel clutch is stepped on or the three-point link is raised. This PTO automatic switch 189 is mainly used during paddy field work.

Reference numeral 190 denotes a diff lock switch. When the diff lock switch is pressed once outward, the diff lock state is set. It cannot be pushed inward, but switches each time it is pushed outward.
Reference numeral 191 denotes a work implement raising / lowering lever, which is lowered on the front side and raised on the rear side. Reference numeral 192 denotes a work implement raising / lowering switch, which is raised to the uppermost position set by the raising adjustment dial 184 by pushing the rear side once, and lowered to the position set by the work implement raising / lowering lever 191 when the front side is pushed once.

  Reference numeral 193 denotes a travel shift increase switch, and 194 a travel shift decrease switch, which is a switch for setting the speed range of the low shift range H1 and the high shift range H2 by the accelerator pedal 173. Each time the travel shift increase switch 193 is pressed once, the start shift stage is shifted up, and every time the travel shift decrease switch 194 is pressed once, the start shift stage is shifted down. It should be noted that a switch for setting the maximum shift speeds of the low shift range H1 and the high shift range H2 may be provided to change the maximum shift speed. Reference numeral 196 denotes a switch box. When the lid is opened, various adjustment switches shown in FIG. 3 are arranged.

  In the switch box 196 in FIG. 3, reference numeral 197 denotes a work machine ascent / descent monitor lamp which is lit and displayed when the work machine is raised and lowered. Reference numeral 198 denotes an AT shift sensitivity dial which changes the sensitivity to increase or decrease the vehicle speed when the AT shift work switch 202 is pressed to perform automatic shifting.

  199 is a descent speed dial that adjusts the descent speed of the work implement. When it is turned to the right, the work implement descends quickly, so it is used for light work implements. Conversely, turning it counterclockwise lowers the work implement slowly, so it is heavy. Used for work machines.

Reference numeral 200 denotes a travel brake adjustment dial, which adjusts the degree of application of the turning brake that acts when the automatic brake on / off switch 208 is turned on.
The AT shift road switch 201 automatically shifts the main transmission devices B and C (four-speed transmission clutch device B and high / low hydraulic pressure switching clutch C) by the accelerator pedal 173 when the sub-shift lever 178 travels on the road, and performs AT shift work. The switch 202 automatically shifts the main transmission with the accelerator pedal 173 during work travel, that is, when the sub-transmission lever 178 is not traveling on the road, and when turned on, the main transmission is switched to the previous time according to the shift position of the sub-transmission lever 178. When the gear is automatically shifted to the longest used gear and turned off, the gear shifts to the main gear that is arbitrarily set according to the gear shift position of the sub-shift lever 178.

  203 is a connection sensitivity shift switch for the main shift, which changes the connection feeling when the main shift is shifted. When the switch is turned on, the monitor is turned on and a gentle shift is performed. When the switch is turned off, the monitor is turned off and suddenly connected. If the connection sensitivity shift switch 203 is turned off and a traction system such as a plow is operated, the shift connection time of the main transmission is shortened, and the operation can be performed lightly.

  Reference numeral 204 is a connection sensitivity PTO switch, which has a rotary, pasture 1 and pasture 2, and when it is set to rotary, the PTO connection becomes faster, and the rotary immediately turns with a rotational force that does not lose the resistance of the soil. When it is set to 2, the connection of PTO becomes loose and it is used with pasture work machines and snow blowers.

205 is a horizontal sensitivity switch, and the operation sensitivity of the automatic horizontal control device of the work machine changes. When the switch is pressed, the movement of the automatic horizontal control becomes slow, and when the switch is pressed again, the operation returns.
Reference numeral 206 denotes a backup on / off switch, and when it is turned on, the work machine automatically rises during reverse travel. 47 is an auto lift on / off switch, and when the handle is turned on, the work machine is automatically raised. 48 is an auto brake on / off switch, and when it is turned on and the handle is turned, only the rear wheel inside the turn is automatically braked.

  209 is a horizontal changeover switch. When the level is automatically leveled, the level of the work implement is automatically maintained by the level sensor. When the level is set manually, the tilt adjustment dial 185 can be adjusted. Are always kept parallel and when tilted, the three-point link is held at a constant tilt angle with respect to the ground.

Reference numeral 210 denotes a 3P changeover switch, which performs control changeover selection based on the lift cylinder mounting position to the three-point link.
211 is an auto accelerator switch, and when the work machine is raised in the on state, the engine speed is reduced to 1700 rpm.

  Numeral 163 shown in FIG. 4 is a meter panel, and is provided in the front panel 174 of the tractor operation unit described above. The meter panel 163 includes a liquid crystal panel, and displays a shift position 160A of the auxiliary transmission lever 178, a gear stage 160B of the main transmission, and a traveling speed 160C. Also, the remaining amount of the fuel tank and the temperature state of the engine coolant are displayed. Prior to these displays, for example, abnormal contents and emergency contents may be displayed.

  FIG. 4A is a display example at a normal time other than on the road. All eight speed stages 160B of the main transmission are displayed, indicating that the auxiliary transmission lever 178 is in the high speed position, the main transmission is in the second speed, and the traveling speed is 2.9 km / h.

  FIG. 4B shows the first to fifth gear positions 160B of the main transmission, the auxiliary transmission lever 178 is on the road traveling position, the main transmission is the second speed in the low transmission range H1, and the traveling speed is 10 It shows that the car is running at 2 km / h.

FIG. 4 (c) shows from 1 to 6 shift stages 160B of the main transmission, and the maximum speed of the low shift range H1 is widened so that the shift range 160B of the main transmission is expanded to 6 speeds. one in which we show the.

  FIG. 4D shows the 4th to 8th gear stages 160B of the main transmission, the auxiliary transmission lever 178 is traveling on the road, the main transmission is the fifth speed in the high transmission range H2, and the traveling speed is 17 It indicates that the vehicle is traveling at 9 km / h.

  FIG. 4 (e) displays from 5 to 8 shift stages 160B of the main transmission, the sub-shift lever 178 is traveling on the road, and the main transmission has changed the minimum shift speed to the fifth speed in the high shift range H2. It shows that the vehicle is traveling at a sixth speed and a traveling speed of 22.1 km / h.

In FIG. 4 (f), the accelerator shift control is released, and the entire shift range 160B is displayed from the first speed to the eighth speed.
FIG. 7 shows a first transmission case 3A having a PTO speed change mechanism G (three forward rotations and one reverse rotation) that changes the output rotational speed from the PTO shaft 11 to a plurality of stages and drives at a constant rotation. It is a power transmission diagram.

  The rotational output of the engine 2 is input to the main input shaft 13 connected to the output shaft of the engine 2 by a joint 105. On the main input shaft 13, the first main gear 106, the second main gear 108, and the third main gear 20 are fixed. The first main gear 106 meshes with the forward rotation gear 107 of the hydraulic forward / reverse clutch A, and the second main gear 108 meshes with the reverse rotation gear 19 of the hydraulic forward / backward clutch A via the first counter gear 18. The third main gear 20 meshes with the PTO input gear 21 of the PTO clutch F to transmit power.

  Accordingly, when the forward clutch A1 of the hydraulic forward / reverse clutch A is engaged, the first main shaft 23 to which the hydraulic forward / reverse clutch A is attached rotates in the forward direction, and when the reverse clutch A2 is engaged, the first main shaft 23 reverses and the PTO clutch F Is inserted, the PTO clutch shaft 103 rotates.

  The rotation of the first main shaft 23 includes a transmission clutch device B that shifts to four hydraulic pressures, a high and low hydraulic pressure switching clutch C that shifts to two levels, and a four-speed transmission D (sub-transmission) that mechanically shifts to four steps. ), And is transmitted to the bevel gear shaft 14 which is the final travel transmission shaft. Therefore, since the shift stage is composed of a four-stage shift (shift clutch device B), a two-stage shift (high / low hydraulic pressure switching clutch C), and a four-stage shift (sub-transmission device D), a total of 4 × 2 × 4 = 32. It is the structure shifted by 32 steps. The first to eighth gears of the main transmission described in FIGS. 4, 5, and 6 are a combination of a shift clutch device B that shifts to four hydraulic stages and a high / low hydraulic switching clutch C that shifts to two levels. It shows that the gear position of.

  The rotation of the front wheel 6 transmitted from the bevel gear shaft 14 can be rotated faster than the rear wheel 7 by the speed increasing clutch E. The sub-transmission D can be shifted to 1st speed (low speed), 2nd speed (medium speed), 3rd speed (high speed), 4th speed (ultra-high speed), but 2nd speed (medium speed), 3rd speed (high speed) ), 4th speed (ultra-high speed) shift is possible without stopping because the synchro mechanism is included. Further, the auxiliary transmission device D may have a three-stage specification. For the 3-speed specification, depending on the model, 1st speed (low speed), 2nd speed (medium speed), 3rd speed (high speed) specifications, 2nd speed (medium speed), 3rd speed (high speed), 4th speed (ultra-high speed) There are specifications, etc., and the configuration can be easily changed by changing only the configuration of the auxiliary transmission device D.

  The rotation of the PTO clutch shaft 103 transmitted from the main input shaft 13 by the third main gear 20 and the PTO input gear 21 is transmitted from the PTO clutch F to the first PTO shaft 22, and the PTO speed change mechanism G is rotated in the three forward rotations and the reverse rotation 1. Shifted to a stage.

Hereinafter, the power transmission mechanism will be described in detail.
The rotation of the first main shaft 23 transmitted by the hydraulic forward / reverse clutch A (the forward clutch A1 and the reverse clutch A2) is transmitted from the first gear 15 fixed to the shaft end to the first transmission gear 16 of the first transmission shaft 24. Is transmitted to the first transmission shaft 24. The first speed change shaft 24 is equipped with a first-speed / third-speed shift clutch B1 of a four-speed hydraulic shift clutch device B. Further, the first transmission gear 15 is transmitted to the second transmission shaft 25 via the second transmission gear 17 of the second transmission shaft 25. The second transmission shaft 25 is mounted with a second-speed / four-speed transmission clutch B2 of a transmission clutch device B with a hydraulic four-speed transmission.

A configuration for transmitting the rotation of the first transmission shaft 24 and the second transmission shaft 25 to the second main shaft 42 will be described.
When the first speed clutch B11 is connected, the second main shaft 42 is rotated by being transmitted from the seventh gear 40 to the sixth gear 39 that is spline-fitted to the second main shaft 42. When the second speed clutch B22 is connected, the second main shaft 42 is rotated by being transmitted from the ninth gear 38 to the eighth gear 37 that is spline-fitted to the second main shaft 42.

  When the third speed clutch B13 is connected, the second main shaft 42 is rotated by being transmitted from the eleventh gear 31 to the tenth gear 30 that is spline-fitted to the second main shaft 42. When the fourth speed clutch B24 is connected, the second main shaft 42 is rotated by being transmitted from the thirteenth gear 36 to the twelfth gear 41 that is spline-fitted to the second main shaft 42.

  The rotation of the second main shaft 42 is transmitted to the height switching shaft 44 by the first joint 43. A high / low hydraulic pressure switching clutch C is provided on the high / low switching shaft 44. When the high speed clutch C1 of the high / low hydraulic pressure switching clutch C is connected, the high speed clutch gear 45 is transmitted to the 14th gear 46 of the first countershaft 47, and when the low speed clutch C2 of the high / low hydraulic pressure switching clutch C is connected, the low speed clutch gear 48 is transmitted. To the 16th gear 49 of the counter shaft 47.

  By mounting the hydraulic high / low switching clutch C on the drive side shaft, the inertial rotational force of the hydraulic high / low switching clutch C that is turned off during the shifting of the mechanical four-speed transmission D (sub transmission) can be reduced, and the mechanical four-speed shifting. The synchronization function of the device D (sub transmission) is improved.

  Further, by providing the high / low hydraulic pressure change clutch C between the transmission clutch device B for hydraulic four-speed transmission and the mechanical four-speed transmission device D (sub transmission), two transmission clutch devices B for hydraulic four-speed transmission are provided. By stopping the inertia rotation by heavy biting and disengaging the hydraulic high / low switching clutch C, the sync function of the mechanical four-stage transmission D (sub transmission) works well, and the shift can be performed well.

  The rotation of the first counter shaft 47 is transmitted to the second counter shaft 51 by the second joint 50, and is shifted by the four-stage transmission device D (sub transmission device). When the first transmission clutch D1 of the four-speed transmission D is switched to the 18th gear 53 side, the bevel gear shaft 14 is driven at an ultra high speed by being transmitted from the 17th gear 52 to the 18th gear 53.

  Further, when the first transmission clutch D1 of the four-speed transmission D (sub transmission) is switched to the twentieth gear 55 side, the bevel gear shaft 14 is driven at a high speed by being transmitted from the nineteenth gear 54 to the twentieth gear 55. .

  When the second transmission clutch D2 of the four-speed transmission D (sub transmission) is switched to the 22nd gear 57 side, the transmission is transmitted from the 19th gear 54 to the 20th gear 55, and then from the 25th gear 60 to the 26th gear 61. And the bevel gear shaft 14 is driven at a medium speed by being transmitted from the 27th gear 62 to the 28th gear 63.

  Further, when the second speed change clutch D2 is switched to the 24th gear 59 side, it is transmitted from the 19th gear 54 to the 20th gear 55, transmitted from the 25th gear 60 to the 26th gear 61, and from the 27th gear 62 to the 28th gear. The gear 63 is transmitted, the 22nd gear 57 is transmitted to the 21st gear 56, the 23rd gear 58 is transmitted to the 24th gear 59, and the bevel gear shaft 14 is driven at a low speed.

  The four-speed transmission D (sub-transmission) has a two-axis configuration of the bevel gear shaft 14 and the second counter shaft 51 by loosely fitting the 21st gear 56 and the 26th gear 61 to the second counter shaft 51. , Space saving.

  For the four-speed transmission D (sub-transmission), the 17th gear 52 for shifting, the 19th gear 54, the 26th gear 61, the 27th gear 62, the 21st gear 56, and the 23rd gear. Since the gear 58 is provided on the second counter shaft 51, the synchronization function is improved.

By tightening the shaft end of the bevel gear shaft 14 with a nut 27, it becomes possible to adjust the manufacturing error of the axial width of each gear or clutch, and it is possible to configure with high accuracy. (Fig. 11)
The rotation of the bevel gear shaft 14 is such that the first bevel gear 64 formed integrally with the bevel gear shaft 14 meshes with the second bevel gear 66 of the rear wheel drive shaft 65, and the rear bevel gear set 83 (differential device) and the rear wheel drive shaft are engaged. The rear wheel shaft 5 to which the rear wheel 7 is mounted is driven through the rear wheel gear set 84 and 65.

  The 29th gear 67 that is spline-fitted to the end portion of the bevel gear shaft 14 is fixed to the first front wheel drive shaft 71 via the 30th gear 68 and the 31st gear 69 (spline fitting) to the 32nd gear 70. The first front wheel drive shaft 71 is configured to be engaged with each other.

  When the front wheel speed change clutch E is attached to the front shaft end of the first front wheel drive shaft 71 and the constant speed clutch E2 of the front wheel speed change clutch E is connected, the rotation of the first front wheel drive shaft 71 remains as it is and the second front wheel drive shaft 71 It is transmitted to 79. When the speed increasing clutch E1 of the front wheel speed change clutch E is connected, the rotation of the first front wheel drive shaft 71 is increased through the 33rd gear 75, the 34th gear 76, the 35th gear 78, and the 36th gear 77 to increase the speed. 2 It is configured to be transmitted to the front wheel drive shaft 79.

The tip of the second front wheel drive shaft 79 drives the front wheel shaft 4 to which the front wheel 6 is mounted via the front bevel gear set 80 (differential device), the front vertical drive shaft 81, and the front planetary gear set 82 as in the prior art. .
The rotation of the PTO input gear 21 is configured to rotate the second PTO shaft 73 from the PTO clutch shaft 103 through the third joint 85, the first PTO shaft 22, and the fourth joint 86 by inserting the PTO clutch F.

The PTO clutch shaft 104 provided side by side with the second PTO shaft 73 constitutes a PTO transmission mechanism G, and is provided with a first PTO transmission clutch G1 and a second PTO transmission clutch G2.
When the first PTO speed change clutch G1 is put on the 38th gear 88 side, the rotation of the second PTO shaft 73 is transmitted to the PTO clutch shaft 104 through the 37th gear 87 and the 38th gear 88 at a low speed. When the first PTO speed change clutch G1 is placed on the 40th gear 91 side, the rotation of the second PTO shaft 73 is transmitted to the PTO clutch shaft 104 through the 39th gear 90 and the 40th gear 91 at medium speed.

  When the second PTO speed change clutch G2 is placed on the 42nd gear 93 side, the rotation of the second PTO shaft 73 is transmitted to the PTO clutch shaft 104 via the 41st gear 92 and the 42nd gear 93 at a high speed. When the second PTO speed change clutch G2 is placed on the 44th gear 96 side, the rotation of the second PTO shaft 73 is transmitted by the reverse rotation of the PTO clutch shaft 104 via the 43rd gear 95, 45th gear 101 and 44th gear 96. . The 45th gear 101 is supported by the counter shaft 97.

The power transmitted to the PTO clutch shaft 104 is configured to rotationally drive the PTO 11 via the PTO joint 74a and the PTO connection shaft 74.
FIG. 8 shows a power transmission configuration in the second mission case 3B described above. The configuration in the second mission case 3B is configured by changing a part of the PTO transmission mechanism G in the configuration of the first mission case 3A. The second transmission case 3B also has a sub-speed four-speed specification. However, the rotation of the PTO shaft 11 is a vehicle speed corresponding PTO transmission mechanism H that changes the speed by following the rotation of the PTO shaft 11 according to the vehicle speed of the tractor. I have.

  The 43rd gear 95 of the 2nd PTO shaft 73 which meshes with the 45th gear 101 currently supported by the counter shaft 97 shown in FIG. 8, the 46th gear 98 is provided on the counter shaft 97 to which the 45th gear 101 is fixed (spline fitting). The 46th gear 98 meshes with the 30th gear 68.

  Thus, the rotational power after passing through the auxiliary transmission D is transmitted from the 29th gear 67 of the bevel gear shaft 14 to the 46th gear 98 via the 30th gear 68. Further, as described above, the power transmitted to the 30th gear 68 is also transmitted to the first front wheel drive shaft 71 via the 31st gear 69 and the 32nd gear 70.

  When the second PTO speed change clutch G2 is switched to the 44th gear 96 side, the PTO clutch shaft 104 is transmitted from the 29th gear 67 through the 30th gear 68, the 46th gear 98, the 45th gear 101, and the 44th gear 96. go. As a result, the PTO clutch shaft 104, that is, the PTO shaft 11 rotates and fluctuates in accordance with the rotational fluctuation of the bevel gear shaft 14, resulting in a PTO rotation corresponding to the traveling speed (ground PTO).

  The 30th gear 68 that receives the rotation from the 29th gear 67 and the 31st gear 69 that transmits the rotation to the 32nd gear 70 are integrated, and the 30th gear 68 is used to mesh with the 46th gear 98. Thus, since the rotation of the PTO shaft 11 is configured to obtain traveling speed compatible PTO rotation, the first mission case 3A and the second mission case 3B can be shared.

In addition, the 30th gear 68 and the 31st gear 69 which are integrally configured are loosely fitted to the PTO clutch shaft 104 of the coaxial PTO transmission mechanism G, whereby the configuration can be simplified.
As described above, the 44th gear 96 outputs the PTO reverse rotation output and the PTO vehicle speed corresponding rotation output (PTO vehicle speed synchronized rotation) in common. Further, since the PTO speed change mechanism G is provided immediately before the 44th gear, the number of parts is reduced and the structure is compact.

  Further, the 29th gear 67 described above is provided close to the mechanical four-speed transmission D (sub-transmission), and both the left and right front wheels 6 and 6 are driven from the 29th gear 67 and the PTO vehicle speed sync drive is driven. Therefore, the number of parts can be reduced and a compact configuration can be achieved.

  As shown in FIG. 9, in the second transmission case 3 </ b> B, another shaft support case piece 100 that supports the counter shaft 97 with the bearings 109 and 110 is configured, but the 45th gear 101 that meshes with the 44th gear 96, A 46th gear 98 that meshes with the 30th gear 68 is spline-fitted to the counter shaft 97.

  In the case where the configuration of the first mission case 3A shown in FIG. 7 is changed to the configuration of the second mission case 3B shown in FIG. 8, the second PTO shaft 73 shown in FIG. The 43 gear 95 is not necessary, so that the 43rd gear 95 is not attached (FIG. 8), or it is slid and fixed to a position where it does not mesh with the 45th gear 101. Further, even if the 43rd gear 95 is left, there is no problem because the second PTO shaft 73 only idles. It should be noted that by changing the number of teeth of each of the 44th gear 96 and the 45th gear 101, it is possible to obtain a variation in speed change.

  Further, as shown in FIG. 10, the first mission case 3A is also configured to share another shaft support case piece 100 used in the second mission case 3B. That is, only the 45th gear 101 that meshes with the 44th gear 96 is spline-fitted to the counter shaft 97 that is supported by the bearings 109 and 110. The counter shaft 97 does not have the 46th gear 98 attached thereto.

  Since the 45th gear 101 of the counter shaft 97 is not removed, it may be integrated by forging or the like when the production number is large, but it is better to integrate by spline fitting when the production number is small. Can be manufactured at a reduced cost.

  Further, the low-speed / medium-speed / high-speed / reverse shift gear positions of the PTO rotation in the first mission case 3A and the low-speed / medium / high-speed / vehicle speed shift gear positions of the PTO rotation in the second mission case 3B. For this reason, the PTO speed change lever can be constituted by one, and it becomes an inexpensive structure, and both speed change operations can be made the same operation.

  Since the shaft support case piece 100 is configured to be detachable from the first mission case 3A and the second mission case 3B with bolts 111, it is possible to easily change the specification by removing the shaft support case piece 100. It becomes possible. Further, the bearing 109 penetrating the boss portion of the shaft support case piece 100 is fixed by a retaining ring 113.

Next, the flow of control signals will be described with reference to the control block diagram of FIG.
First, the engine controller 124 receives the exhaust temperature from the engine exhaust temperature sensor 125, the engine speed from the engine rotation sensor 126, the engine lubricating oil pressure from the engine oil pressure sensor 127, and the engine water temperature sensor 128. The temperature of the cooling water enters, the pressure of the common rail enters from the rail pressure sensor 129, the drive signal is output to the fuel high-pressure pump 130, and the fuel supply adjustment control signal is output to the high-pressure injector 131.

  Next, the work implement elevating controller 132 includes an operation signal for the work implement elevating sensor 123 provided on the work implement elevating lever, an elevating signal for the lift arm sensor 122, a raising position restriction signal for the raising adjustment dial 120, and a lowering for the lowering speed dial 121. A speed setting signal is input, and a work implement lift signal is output to the main lift solenoid 133 and the main drop solenoid 134 to operate the work lift cylinder 135.

  The engine controller 124, work implement lifting controller 132, and travel system controller 149, which will be described later, communicate with each other, and the meter panel 136 displays the engine status, the lift status of the work implement, the travel speed of the travel device, etc. The operation position of each lever and pedal is displayed on the panel 137.

  The travel system controller 149 receives a clutch engagement signal from the shift 1 clutch pressure sensor 138, the shift 2 clutch pressure sensor 139, the shift 3 clutch pressure sensor 140, and the shift 4 clutch pressure sensor 141. In other words, the gear position of the four-speed hydraulic transmission clutch device B is input. Further, high / low switching signals of the high / low hydraulic pressure switching clutch C are inputted from the high speed clutch pressure sensor 142 and the low speed clutch pressure sensor 143.

  The shift position of the four-speed transmission D (sub-transmission) is input from the auxiliary transmission lever operation position sensor 147, and the forward / neutral / reverse of the hydraulic forward / reverse clutch A is input from the forward clutch pressure sensor 144 and the reverse clutch pressure sensor 145. To do. For forward / reverse movement, a forward / reverse shift operation position signal is input from the forward / reverse lever operation position sensor 146. A mode switching signal is input from the accelerator mode changeover switch 148, and an accelerator instruction signal is input from the accelerator sensor 159 of the throttle lever.

  Further, the travel system controller 149 receives a signal for increasing the shift speed of the low shift range H1 and the high shift range H2 of the accelerator control from the travel shift increase switch 193, and a signal for decreasing the shift speed from the travel shift decrease switch 194, A traveling speed is input from the vehicle speed sensor 163, an oil temperature is input from the mission oil temperature sensor 164, and a switching signal of the four-speed transmission D (sub transmission) is input from the clutch button 162.

  As for the output from the travel system controller 149, the switching signal of the forward / reverse switching clutch 101 is output to the forward / reverse switching solenoid 150, and the hydraulic relief pressure adjustment signal for driving the forward / reverse switching solenoid 150 is output to the linear boost solenoid 151. Reduce the shock of clutch connection.

  An on / off signal is output to the clutch solenoid 152. A first-speed or third-speed input signal is output to the shift 1-3 switching solenoid 153 of the hydraulic cylinder that drives the first shift clutch 102 for switching the 1st / 3rd speed. A hydraulic relief pressure adjustment signal for driving the 1st / 3rd clutch is output to the shift 1-3 boost solenoid 154 to reduce the shock of clutch engagement. A second-speed or fourth-speed input signal is output to the shift 2-4 switching solenoid 155 of the hydraulic cylinder that drives the second shift clutch 103 for 2-speed / 4-speed switching. A relief pressure adjustment signal for hydraulic pressure for driving the 2nd / 4th clutch is output to the shift 2-4 boost solenoid 156 to reduce the shock of clutch engagement. A high-speed clutch engagement signal and a low-speed clutch engagement signal are output to a high-speed clutch switching solenoid 157 and a low-speed clutch switching solenoid 158 that operate a hydraulic cylinder that drives the high / low speed switching clutch 107.

B Shift clutch device (hydraulic four-speed shift clutch device)
C switching clutch (high / low hydraulic switching clutch)
D Sub-transmission (mechanical 4-speed clutch)
147 Sub shift detection means
160 accelerator shift setting switch
162 clutch button 173 accelerator pedal
178 Sub-shift lever
193 Travel shift up switch
194 travel shift lowering switch H1 shift range (low shift range)
H2 shift range (high shift range)

Claims (2)

In a transmission for a work vehicle in which a transmission clutch device (B), a switching clutch (C), and an auxiliary transmission device (D) are provided in a transmission case, the transmission clutch device (B) and the switching clutch (C) are automatically shifted. A sub-shift detecting means (147) for detecting the shift position of the sub-transmission device (D) is provided, and when the sub-shift detection means (147) detects a road traveling shift position, an accelerator pedal (173) The shift clutch device (B) and the switching clutch (C) are automatically shifted in a plurality of speeds by the operation of the shift clutch device (B) and the switching clutch (C). A plurality of shift ranges (H1) and (H2) are provided, and the plurality of shift ranges (H1) and (H2) can be appropriately selected .
A travel shift increase switch (193) and a travel shift decrease switch (194) for setting the starting shift speeds of the plurality of shift ranges (H1) and (H2) are provided, and the maximum of the plurality of shift ranges (H1) and (H2) is provided. A switch to change and set the gear position is provided.
An auxiliary shift lever (178) for performing a shift operation of the auxiliary transmission (D) is provided, and an accelerator shift setting switch (160) for selecting a plurality of shift ranges (H1), (H2) on the auxiliary shift lever (178). And a plurality of shift ranges (H1) and (H2) can be selected,
After the plurality of shift ranges (H1) and (H2) are selected and set by the accelerator shift setting switch (160), the automatic shift control by the accelerator pedal is released or the automatic shift by the accelerator pedal is again performed after the engine is stopped. When the control is executed, it is configured to change to the shift range set immediately before,
A work vehicle transmission comprising a clutch button (162) capable of changing the plurality of shift ranges (H1) and (H2) when the sub-shift lever (178) is at a road travel position . 2. The work vehicle according to claim 1, wherein each time the travel shift increase switch (193) or the travel shift decrease switch (194) is pressed once, the starting shift stage is shifted up or down. Gearbox.

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