JP2005273758A - Shift control device of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem as a troublesome operation according to the conventional arrangement in which changing-over into the accelerator auto-shifting must be made by an accelerator pedal each time the shift operation has been changed over to the operation by a shift lever even if an auxiliary transmission device is changed over to the high speed side when one wishes moving on a road at a high speed. <P>SOLUTION: The invention applies to a working vehicle equipped with a shifting means through which the power is transmitted to running wheels upon speed changing a driving force given from an engine, wherein the arrangement further includes an accelerator sensor to sense the opening of an accelerator, an engine speed sensor to sense the engine speed, and an operation part from which changing-over is made into the working mode and the moving mode, and the accelerator shifting is made effective when changing-over is made into the moving mode while the operation with the shift lever is made effective when changing-over is made into the working mode, and the moving mode is generated when shifting is made to the auxiliary shift position where at least maximum speed can be specified so that it is possible to generate the accelerator auto-shifting. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission control device for a work vehicle for agriculture such as a tractor, transportation, or construction.

Conventionally, as a technology of a vehicle shift control device (see, for example, Patent Document 1), when an accelerator pedal angle sensor is connected to a controller by a changeover switch, a rotation angle of the accelerator pedal is detected by the pedal angle sensor, Inputs to the controller, automatic shift operation is performed in conjunction with the depression angle of the accelerator pedal, shifting can be performed without operating the travel shift lever, and the angle sensor of the travel shift lever is switched to the controller When connected, the rotation angle of the travel shift lever is detected by the lever angle sensor, and when it is input to the controller, the travel shift operation is not linked to the accelerator pedal, so that the shift operation can be performed with the travel shift lever. ing.
JP 2000-18375 A

  In such a prior art, when it is desired to move at high speed while traveling on the road, even if the sub-transmission device is switched to the high speed side, if the shift operation is switched to the operation by the shift lever, the accelerator pedal is automatically operated by the accelerator pedal. There has been a problem that the operation becomes troublesome because it is necessary to switch to a speed change operation.

  An object of the present invention is to solve the above problems and improve operability.

  In order to solve the above problems, the present invention has taken the following technical means.

  That is, the present invention according to claim 1 is a work vehicle equipped with a speed change means for shifting the driving force from the engine and transmitting the power to the traveling wheels. The accelerator sensor for detecting the opening degree of the accelerator and the engine speed are set. An engine rotation sensor to detect is provided, and an operation unit that can be switched between the work mode and the movement mode is provided, and the accelerator shift is enabled when switching to the movement mode, and the operation with the shift lever is performed when switching to the work mode. Is effective, and at the time of shifting to a sub-shifting position where at least the maximum speed can be designated, the accelerator mode is configured so that the accelerator can be automatically shifted as a movement mode.

  When the operation mode is switched by the changeover switch of the operation unit, the operation with the speed change lever becomes effective, and any speed change operation within the work speed range is performed with the speed change lever.

  Further, when the mode is switched to the movement mode by the changeover switch, the accelerator shift becomes effective, and the accelerator automatic shift is performed by depressing the accelerator pedal.

  Further, when the sub-transmission device is shifted to the high speed side when traveling on the road, even if the shift position at this time is in the work mode, it automatically shifts to the movement mode without switching the changeover switch, Automatic shifting can be performed to the maximum speed by operating the accelerator.

  According to a second aspect of the present invention, in the first aspect, when the movement mode is switched to the work mode, the shift speed is automatically changed to the work speed position designated by the shift lever. .

  For this reason, at the time of switching to the work mode, a shift at a predetermined work speed position is performed, so that when the mode is switched by moving at high speed between the fields, the operation can be shifted as it is.

  According to a third aspect of the present invention, in the first or second aspect, when the operation mode is switched to the movement mode, an automatic accelerator shift can be performed.

  By simply switching to the travel mode, it is possible to perform automatic accelerator shifting, improving operability.

  In short, according to the first aspect of the present invention, especially when traveling on the road, if the sub-transmission device is shifted to the high speed side, even if the shift position at this time is in the work mode, the selector switch is not switched. It is possible to automatically shift to the movement mode and automatically shift to the maximum speed by the accelerator operation, so that the operability can be improved and the work efficiency can be improved.

  According to the invention of claim 2, while achieving the effect of the invention of claim 1, at the time of switching to the work mode, the gear shift operation is performed at a predetermined work speed position, so that the high-speed movement between the fields Then, it is possible to shift to the work as it is by simply switching the mode, and it is possible to prevent troubles such as engine stall due to high-speed movement.

  Further, according to the invention of claim 3, although the effects of the invention of claim 1 or claim 2 are produced, it is possible to perform the automatic accelerator shift only by switching to the movement mode, thereby improving the operability. it can.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an agricultural tractor which is an example of a work vehicle. An engine E is mounted on the front portion of the tractor 1, and the rotational power of the engine E is transmitted to a transmission 3 in a transmission case 2. The rotational power decelerated by the transmission 3 is transmitted to the front wheels 4 and the rear wheels 5. A hydraulic cylinder case 6 is provided in the upper part of the transmission case 2, and a lift arm 7 is pivotally attached to the hydraulic cylinder case 6. When the hydraulic oil is supplied into the hydraulic lift cylinder 8 in the hydraulic cylinder case 6, the lift arm 7 is turned upward, and when it is discharged, the lift arm 7 is lowered.

  The lift arm 7 and the lower link 9 are connected by a lift rod 10, and a rotary tiller 12 is connected to the lower link 9 and the top link 11 as a working machine. It is the structure to do.

  The steering handle 13 is configured to steer the left and right front wheels 4 to the left and right by a left and right rotation operation, and a cockpit 14 is provided behind the steering handle 13. A main transmission lever 15 and an auxiliary transmission lever 16 are provided near the cockpit 14, a throttle lever 17 is provided near the steering handle 13, and an accelerator pedal 18 is provided near the feet below the handle 13. . The accelerator pedal 18 is linked to the throttle of the engine E through a wire or the like, and is configured to control the rotational speed of the engine E in accordance with the amount by which the accelerator pedal 18 is depressed.

  FIG. 2 shows a configuration example of the pipe 22 that connects the suction filter 21 to the rear mission case 2b. The connection end portion 22a on the transmission case 2b side of the pipe 22 is connected from the lateral outer surface portion of the case 2b (conventionally, as shown in FIGS. 2A and 2B, the connection end portion 22a is connected from the lower surface of the transmission case). In addition, the piping line between the connecting end 22a and the connecting end 22b on the filter 21 side is configured to be parallel. This facilitates the removal of the piping when replacing the suction filter and facilitates maintenance. Also, as shown in FIGS. 2 and 3, if the pipe is connected from the mission case 2b via the metal 23, the metal mounting portion can be freely rotated and displaced. The position of the filter can be changed to an arbitrary angle.

  As shown in FIG. 4 (a), since there is a clearance L between the filter and the mounting case 24 in the prior art, the position is not fixed, which causes vibrations due to play, but in this example, FIG. As shown in FIG. 4B, it can be solved by providing the collar 25, and as shown in FIG. 4C, it can also be eliminated by forming the shape of the filter into a tapered shape 21t whose diameter increases toward the base side. It is possible to suppress the vibration due to the backlash of the filter, and to prevent noise based on the backlash.

  In the configuration example shown in FIG. 5, when performing failure diagnosis of the control device of the tractor, the failure diagnosis result is displayed on the mobile phone HT by wired or Internet mail. If the display is a mobile phone, a dedicated display device is not necessary, and a diagnosis result can be easily obtained. In the illustrated example, the cellular phone HT is set in a holder 27 provided on the operation panel 26 on the operation box. In addition, when working on the tractor, if measures such as reducing the engine speed by reducing the engine speed by judging the incoming call from radio waves etc. as a response when a call is received to the mobile phone, Can be made easier and calls can be made easier.

  FIG. 6 shows a power transmission path diagram of the traveling system of the tractor. A main shaft 30 is installed in the flywheel housing 2a joined to the transmission case 2 and the front part thereof in the front-rear direction, via the flywheel. Thus, the rotational power of the engine E is transmitted. The main shaft 30 is connected at its rear end to a PTO drive shaft 41 for driving a PTO shaft 40 installed in the rear mission case 2b, and the rear end of the PTO drive shaft 41 is connected to a PTO clutch 42. Yes.

  A hydraulic type forward / reverse switching clutch 32 is provided on the main shaft 30, and the switching clutch 32 is appropriately switched by the operation of the forward / reverse switching valve 43 by the forward / reverse switching lever 19. The gear 33 on the hollow shaft 31 that is rotatably fitted on the main shaft 30 is driven in the forward rotation direction or the reverse rotation direction so that the machine body can be moved forward or backward.

  The transmission case 2 is provided with a main transmission 50 capable of four-speed gear shifting (main speeds 1 to 4) and a sub-transmission device 51 capable of high and low two-speed gear shifting.

  The main transmission 50 includes drive transmission gear trains K1 to K4 mounted on the hollow shaft 31, and driven transmission gear trains J1 to J4 that are loosely fitted on the drive shaft 34 and always mesh with the drive transmission gear trains K1 to K4. And first, second, third and fourth hydraulic clutches 35a, 35b, 35c and 35d disposed between the drive shaft 34 and the driven transmission gear trains J1 to J4. ing. That is, the driven transmission gear trains J1 to J4 on the drive shaft 34 transmit the driving force from the hollow shaft 31 to the drive shaft 34 by the operation of the hydraulic clutch 35. The rear end of the drive shaft 34 is linked to the auxiliary transmission 51. The auxiliary transmission 51 includes a high speed gear H1 fixed to the rear end of the drive shaft 34, a low speed gear H2 rotatably fitted on a second drive shaft 36 coaxial with the drive shaft 34, and a high speed gear H1. An axially slidable slider 37 interposed between the low speed gear H2 and a gear G1, which is fixed to the sub hollow shaft 38 fitted on the main shaft 30 and meshes with the high speed gear H1 and the low speed gear H2. It consists of G2.

  The slider 37 is slidable in the axial direction by the operation of the auxiliary transmission lever 16, and when meshed with the high speed gear H1, high speed rotation is transmitted to the second drive shaft 36, and when the slider 37 is meshed with the low speed gear H2. The low speed rotation is transmitted from the high speed gear H1 to the second drive shaft 36 via the gear G2 and the low speed gear H2 on the auxiliary hollow shaft 38. The rear wheel 5 is driven from the second drive shaft 36 via the differential gear device and the rear wheel drive gear 39.

  FIG. 7 is a block circuit diagram of a shift control device that controls shift switching. From a potentiometer that detects an operation amount of a shift hydraulic cylinder as a main shift lever 15 on the input side of a controller 60 as a control unit. A main transmission lever position sensor 61, a sub transmission lever position sensor 62 as the sub transmission lever 16, a main transmission first speed pressure sensor 63a for detecting the pressure of the main transmission hydraulic oil, a main transmission second speed pressure sensor 63b, A shift 3-speed pressure sensor 63c, a main shift 4-speed pressure sensor 63d, an engine rotation sensor 64 for detecting the rotation speed of the engine E, an accelerator sensor 65 for detecting the accelerator opening in conjunction with the depression of the accelerator pedal, A mode selector switch 66 that can be switched from the moving mode to the working mode and from the working mode to the moving mode is connected. On the output side of the roller 60, main transmission 1st to 4th speed valves 67a, 67b, 67c for controlling the main transmission hydraulic cylinder corresponding to the main transmission 1st to 4th pressure sensors 63a, 63b, 63c, 63d. 67d, a forward / reverse switching valve 43 for switching the hydraulic forward / reverse switching clutch 32 to forward / reverse, and a clutch boost control valve 68 of the hydraulic forward / reverse switching clutch 32 are connected.

  The mode changeover switch 66 is installed on the operation panel 26 shown in FIG. 5 and has a rotatable dial type switch configuration. The mode changeover switch 66 has a movable mode when traveling on the road and work during plowing work on the field. You can switch between modes. The work speed in this work mode includes “low speed”, “medium speed”, and “high speed” within the work speed range.

  When the mode is switched to the work mode by the mode switch 66, the operation with the main shift lever 15 becomes effective, and any shift operation within the work speed range is performed by the shift lever 15.

  Further, when the mode is switched to the movement mode by the mode change switch 66, the shift of the accelerator operation becomes effective, and the accelerator automatic shift accompanying the rotation of the engine is performed by the depression of the accelerator pedal 18.

  Further, when traveling on the road, if the subtransmission device 51 is shifted to the high speed side by operating the subtransmission lever 16, the mode selector switch 66 is switched even if the main shift position at this time is in the work mode. Instead, it automatically shifts to the movement mode and can automatically shift to the maximum speed by the accelerator operation by the accelerator opening and the engine rotation.

  Further, when switching from the movement mode to the work mode, the operation speed position is automatically changed to the work speed position designated by the main shift lever, that is, when shifting to the work mode, the shift is performed at the predetermined work speed position. After moving between the farm fields at high speed, the work can be continued as it is at a predetermined work speed in the farm field before the movement only by switching the mode to the work mode.

It is a side view of a tractor. It is the top view (A) and side view (B) which show the piping structure of a suction filter, and shows a prior art example and this plan. It is S1-S1 sectional drawing of the principal part same as the above. It is a side view of a filter, (A) is a conventional example, (B), (C) is the present plan. It is a top view of the operation panel part of an operation box. It is a power transmission route diagram. It is a control block circuit diagram. It is a vehicle speed range. It is a flowchart.

Explanation of symbols

E Engine 1 Tractor 2 Mission case 4 Front wheel 5 Rear wheel 15 Main transmission lever 16 Sub transmission lever 18 Accelerator pedal 19 Forward / reverse switching lever 32 Hydraulic forward / reverse switching clutch 35 Hydraulic clutch 43 Forward / reverse switching valve 50 Main transmission 51 Sub transmission Device 60 Controller 61 Main transmission lever position sensor 62 Sub transmission lever position sensor 63 Main transmission pressure sensor 64 Engine rotation sensor 65 Acceleration sensor 66 Mode selector switch

Claims (3)

  In a work vehicle having a speed change means for shifting the driving force from the engine and transmitting power to the traveling wheels, an accelerator sensor for detecting the accelerator opening and an engine rotation sensor for detecting the engine speed are provided. In addition to providing an operation unit that can be switched between the mobile mode and the mobile mode, the accelerator shift is effective when switching to the mobile mode, and the operation with the shift lever is effective when switching to the work mode. And a shift control device for a work vehicle, wherein the shift control device is configured so that an accelerator can be automatically shifted as a movement mode when shifting to a sub-shift position where at least the highest speed can be designated.   2. A shift control apparatus for a work vehicle according to claim 1, wherein the shift control device is configured to automatically change to a work speed position designated by a shift lever when switching from the movement mode to the work mode.   The shift control device for a work vehicle according to claim 1 or 2, wherein an automatic accelerator shift is possible when switching from the work mode to the movement mode.

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