JP5032894B2 - Working vehicle - Google Patents

Description

  The present invention relates to a tractor including a traveling main transmission that performs a traveling shift in accordance with the operation of an actuator, and a shift control device that shifts the traveling main transmission by operating the actuator according to an artificial acceleration / deceleration command. This relates to a working vehicle.

  A working traveling vehicle having a traveling main transmission that performs a traveling shift according to the operation of an actuator and a shift control device that shifts the traveling main transmission by operating the actuator according to an artificial acceleration / deceleration command is known. It has been. Usually, this type of working vehicle is provided with an acceleration switch or a deceleration switch for shifting the traveling main transmission, and each time the acceleration switch or the deceleration switch is operated, the transmission control device However, the travel main transmission is shifted one step at a time to the speed increasing side or the speed reducing side.

Further, the speed change control device is provided with initial setting means for determining an initial gear position of the traveling main speed change device when the key switch is changed from the OFF state to the ON state. As the initial setting means, the gear stage stored before the key switch is turned off is used as the initial gear stage, or a predetermined gear stage (a preset gear stage (regardless of the gear stage before the key switch is turned off) ( For example, there is known one having the first speed) as an initial shift stage (see, for example, Patent Document 1).
Japanese Patent No. 3031810

  In the case where the gear stage stored before the key switch is turned off is used as the initial gear stage, the gear stage is maintained even if the operation is interrupted, so that the work can be performed quickly without operating the speed increasing switch or the speed reducing switch. However, if the memorized shift speed is on the high speed side, the aircraft may start suddenly or an engine stall may occur due to overload.

  In particular, in a working vehicle equipped with a traveling sub-transmission that is mechanically shifted according to human operation, the speed of the traveling sub-transmission is changed from low to high while the key switch is off. Therefore, if the shift stage memorized before the key switch is turned off is used as the initial shift stage, the speed change state becomes faster than before the key switch is turned off, and sudden start or stall is possible. Will increase.

  On the other hand, regardless of the shift stage before the key switch is turned off, the predetermined shift stage (for example, the first speed) set as the initial shift stage can prevent sudden start and engine stall. Each time the work is restarted, a resetting operation of the gear position is required, which is not only inferior in operability but also takes time to restart the work.

The present invention was created in view of the above circumstances and has been created for the purpose of solving these problems. The invention of claim 1 is a traveling main transmission that performs traveling shifting according to the operation of an actuator. A shift control device that is activated in response to an operation of turning on a key switch and that shifts the main drive transmission by operating the actuator in response to an artificial acceleration / deceleration command. The apparatus includes gear stage storage means for storing the current gear position of the main driving transmission, and initial setting means for determining an initial gear stage of the main driving transmission when the key switch is switched from the OFF state to the ON state. provided, initial setting unit, when shift speed stored before the key switch is turned off is a shift speed of the low speed side selects the gear speed the storage as the initial gear, key switch When the shift stage stored before being turned off is the high-speed shift stage, the predetermined low-speed shift stage is set as the initial shift stage regardless of the stored shift stage. It is a working traveling vehicle characterized by having it.
In this way, when setting the initial gear position of the main driving transmission according to the key switch on operation, it is possible to set an appropriate gear position according to the situation. For example, when the shift stage stored before the key switch is turned off is a low speed shift stage, there is no fear of sudden start or engine stall, so by setting the stored shift stage as the initial shift stage, It is possible to quickly resume the work, and when the shift stage stored before the key switch is turned off is the high-speed shift stage, a predetermined preset shift stage is set regardless of the stored shift stage. By setting the initial gear position, sudden start and engine stall can be prevented.
According to a second aspect of the present invention, a traveling main transmission that performs a traveling shift in response to an operation of an actuator, a traveling sub-transmission that is mechanically operated in response to an artificial operation, and a key switch input operation. And a shift control device that shifts the travel main transmission by operating the actuator in response to an artificial acceleration / deceleration command, the shift control device has a key switch turned off. When the shift speed of the traveling sub-transmission device is changed to the high speed side during this period, a predetermined low-speed gear set in advance is selected as the initial shift speed, and the shifting of the traveling sub-transmission device is performed while the key switch is turned off The working vehicle is configured to select a predetermined high speed as an initial gear when the speed is changed to a low speed .
In this way, when setting the initial gear position of the main driving transmission according to the key switch on operation, it is possible to set an appropriate gear position according to the situation. For example, if the gear position of the traveling sub-transmission device is changed to the high speed side while the key switch is in the off state, the preset low speed side speed change is performed regardless of the gear position stored before the key switch is turned off. By setting the gear to the initial gear, it is possible to prevent sudden start and engine stall.

  Next, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a tractor (working traveling vehicle). The tractor 1 has a traveling machine body 5 supported by a pair of front wheels 2 and rear wheels 3 arranged on the left and right sides. The traveling machine body 5 includes a bonnet 7 in which an engine 6 (see FIG. 2) is housed in a front portion, and a driver seat portion 8 and the like in a rear portion of the bonnet 7. In addition, a mission case (not shown) that is integrally fixed to the traveling machine body 5 is disposed below the traveling machine body 5. The output of the engine 6 is transmitted to the front wheels 2 and the rear wheels 3 via a transmission provided in the transmission case, and causes the tractor 1 to travel at a required speed in the front-rear direction.

  As shown in FIG. 2, the power from the engine 6 is supplied through the clutch 11, the output shaft 12, the output gear 13 fixed to the output shaft 12, and the input gear 15 meshing with the output gear 13. This is transmitted to the input shaft 16 to which the gear 15 is fixed. A plurality of gears 16a, 16b, 16c, and 16d having different numbers of teeth are integrally fixed to the input shaft 16.

  Further, in the transmission case, a front main transmission (travel main transmission) 20A disposed adjacent to the input shaft 16 and power transmitted from the front main transmission 20A and transmitted downstream is transmitted. An intermittent main clutch 30, a forward / reverse switching device 40 connected to the downstream side of the main clutch 30, and a rear main transmission (traveling main transmission) 20B connected to the downstream side of the forward / backward switching device 40. A sub-transmission device (traveling sub-transmission device) 50 and the like disposed on the downstream side of the rear main transmission 20B are disposed to constitute a traveling drive system.

  In the transmission case, there is a PTO main transmission unit 81 disposed adjacent to the input shaft 16 and a PTO rotation switching device 82 that performs forward / reverse rotation of the PTO shaft 83 on the downstream side of the PTO main transmission unit 81. It arrange | positions and it is comprised so that motive power can be output to a working machine (not shown) via the PTO shaft 83. FIG.

  The front main transmission 20A is provided with a transmission shaft 21 that is supported in a rotating manner with respect to the transmission case, and the transmission shaft 21 has a number of teeth that always mesh with the gears 16a, 16b, 16c, and 16d. The different gears 22a, 22b, 22c, and 22d are supported in a rotating manner. A shift member 23 that can selectively engage and disengage with the gears 22a and 22b by a synchromesh method is provided between the gear 22a and the gear 22b, and a synchronizer between the gear 22c and the gear 22d. Shift members 25 that can be selectively engaged with and disengaged from the gears 22c and 22d by a mesh system are arranged so as to be movable in the axial direction of the transmission shaft 21, respectively.

  The main clutch 30 is constituted by a hydraulic clutch disposed between the front main transmission 20A and the forward / reverse switching device 40, and transmits the output of the front main transmission 20A to the forward / reverse switching device 40 by supplying hydraulic pressure. When the hydraulic pressure is cut off, the output of the front main transmission 20A is not transmitted to the forward / reverse switching device 40, and the power transmission of the travel drive system is cut off.

  The forward / reverse switching device 40 includes an intermediate shaft 42 and a transmission shaft 45 that are rotatably supported by the transmission case in parallel with the input shaft 41. An intermediate gear 42a that meshes with the gear 41a is integrally fixed to the intermediate shaft 42.

  The input shaft 41 is connected to the transmission shaft 21 via the main clutch 30 and rotates together with the transmission shaft 21 when the main clutch 30 is in the engaged state. Gears 41 a and 41 b with different numbers of teeth are integrally fixed to the input shaft 41.

  On the transmission shaft 45, 46b meshing with the gear 41b and 46a meshing with the gear 42a are supported in a rotating manner. Between the gear 46b and the gear 46a, a shift member 47 that is selectively engageable and disengageable with the gears 46a and 46b by a synchromesh method is disposed so as to be movable in the axial direction of the transmission shaft 45. Yes.

  The rear main transmission 20B includes a rear half portion of the transmission shaft 45 and a transmission shaft 28 supported on the transmission case so as to be positioned on the same axis as the input shaft 41.

  Gears 26a and 26b having different numbers of teeth are rotatably supported on the latter half of the transmission shaft 45. A shift member 27 that can selectively engage and disengage with the gears 26a and 26b by a synchromesh method is disposed between the gears 26a and 26b so as to be movable in the axial direction of the transmission shaft 45. ing.

  In the transmission shaft 28, a gear 28a meshing with the gear 26a and a gear 28b meshing with the gear 26b are integrally fixed. Further, gears 28c and 28d having different numbers of teeth are integrally fixed to the transmission shaft 28.

  The gear 28c meshes with the gear 62a. The gear 62a is formed integrally with a gear 62b having a smaller diameter than the gear 62a and is rotatably supported by the transmission shaft 61. The transmission shaft 61 is rotatably supported with respect to the transmission case so as to be positioned on the same axis as the transmission shaft 45. In addition to the gears 62a and 62b, a gear meshing with the gear 28d is also provided. 63 is rotatably supported. A gear 64 is integrally fixed to the transmission shaft 61, and is further arranged to be movable in the axial direction of the transmission shaft 61, and a gear 66 in which a large-diameter gear and a small-diameter gear are integrally formed. Is arranged.

  The sub-transmission device 50 includes an output shaft 51 that is supported in a rotating manner with respect to the transmission case in parallel with the transmission shaft 28 and the transmission shaft 61. A gear 52a meshing with the gear 62b and a gear 52b meshing with the gear 63 are rotatably supported on the output shaft 51. Between the gear 52a and the gear 52b, a shift member 53 that can be selectively engaged with and disengaged from the gears 52a and 52b by a synchromesh method is disposed so as to be movable in the axial direction of the output shaft 51. Yes. A gear 65 that meshes with the gear 66 is integrally fixed to the output shaft 51.

  The output shaft 51 is connected to the rear wheel 3 via a differential gear 71, a drive axle 72, and the like, so that the tractor 1 can be driven. The rotation of the gear 66 is transmitted to the gear 64 via the transmission shaft 61, and the rotation of the gear 66 and the gear 64 is transmitted to the quick turn device 75. In the quick turn device 75, the rotation of one of the gear 66 and the gear 64 is transmitted to the front wheel 2 through the differential gear 17 and the like by the operation of the clutch, so that the tractor 1 can be driven. In addition, by moving the gear 66 along the axial direction of the transmission shaft 61, the transmission of power to the front wheels 2 can be cut off.

  Next, the operation of the tractor 1 will be described.

  For example, the rotation output from the engine 6 is caused by the clutch 11, the output shaft 12, the output gear 13 fixed to the output shaft 12, and the input gear 15 meshing with the output gear 13. It is transmitted to the fixed input shaft 16. The rotation transmitted to the input shaft 16 is transmitted to the front main transmission 20A via a plurality of gears 16a, 16b, 16c and 16d having different numbers of teeth.

  In the front main transmission 20A, when the shift member 23 is in the neutral position separated from the gear 22a and the gear 22b, the gears 22a and 22b are idled with respect to the transmission shaft 21, respectively. When the shift member 23 is engaged with the gear 22a (or gear 22b), the shift member 23 rotates together with the engaged gear 22a (or gear 22b) to rotate the transmission shaft 21.

  Further, when the shift member 25 is in the neutral position separated from the gear 22c and the gear 22d, the gears 22c and 22d are idle with respect to the transmission shaft 21, respectively. When the shift member 25 is engaged with the gear 22c (or gear 22d), the shift member 25 rotates together with the engaged gear 22c (or gear 22d) to rotate the transmission shaft 21.

  That is, the front main transmission 20A is synchronized with the gears 16a, 16b, 16c, 16d, the gears 22a, 22b, 22c, 22d that are always meshed with the gears 16a, 16b, 16c, 16d, and the shift members 23, 25. It is composed of mesh type synchronous mesh gear transmission, and gears 16a and gear 22a, gears 16b and gear 22b, gears 16c and gear 22c, gears 16d and gear 22d, and gears of four stages with different transmission ratios. A stage is set.

  Here, for example, when the main clutch 30 is in the engaged state, the rotation of the transmission shaft 21 is transmitted to the forward / reverse switching device 40 via the input shaft 41.

  In the forward / reverse switching device 40, when the shift member 47 is in the neutral position separated from the gears 46a and 46b, the gears 46a and 46b are idled with respect to the transmission shaft 45, respectively. When the shift member 47 is engaged with the gear 46a (or 46b), the shift member 47 rotates together with the engaged gear 46a (or 46b) to rotate the transmission shaft 45.

  At this time, when the rotation of the gear 46a is transmitted to the transmission shaft 45 and when the rotation of the gear 46b is transmitted to the transmission shaft 45, the rotation direction transmitted to the transmission shaft 45 is reversed by the action of the intermediate gear 42a. . That is, if the rotation transmitted to the transmission shaft 45 via the gear 46b is the rotation in the forward direction of the tractor 1, the rotation transmitted to the transmission shaft 45 via the gear 46a is the rotation in the backward direction of the tractor 1. Thus, the forward / backward switching of the tractor 1 can be performed.

  In the rear main transmission 20B to which the rotation is transmitted by the transmission shaft 45, when the shift member 27 is in the neutral position separated from the gear 26a and the gear 26b, the gears 26a and 26b are respectively idled with respect to the transmission shaft 45. is doing. When the shift member 27 is engaged with the gear 26a (or gear 26b), the shift member 27 rotates together with the engaged gear 26a (or gear 26b) to rotate the transmission shaft 28.

  That is, the rear main transmission 20B is composed of a gear 28a, 28b, gears 26a, 26b that are always meshed with the gears 28a, 28b, and a synchromesh type synchronous mesh gear transmission with a shift member 27. And two gears with different transmission ratios are set by meshing the gear 26a, the gear 26b, and the gear 26b. Thereby, in the main transmission 20 constituted by the front main transmission 20A and the rear main transmission 20B, eight shift stages having different transmission ratios are set.

  The gear 28c fixed integrally with the transmission shaft 28 is transmitted to the auxiliary transmission 50 through the integrally formed gears 62a and 62b, and similarly through the gear 63, respectively.

  In the auxiliary transmission 50, when the shift member 53 is in the neutral position separated from the gear 52a and the gear 52b, the gears 52a and 52b are idled with respect to the output shaft 51, respectively. When the shift member 53 is engaged with the gear 52a (or gear 52b), the shift member 53 rotates together with the engaged gear 52a (or gear 52b) to rotate the output shaft 51.

  In other words, the auxiliary transmission 50 is constituted by a synchromesh-type synchronous meshing gear transmission that includes gears 52a and 52b, gears 62b and 63 that are always meshed with the gears 52a and 52b, and a shift member 53. Two gear stages having different transmission ratios are set by the meshing of the gear 62b, the gear 52b, and the gear 63.

  The rotation of the output shaft 51 is transmitted to the rear wheel 3 via the differential gear 71 and the drive axle 72. In the four-wheel drive state, the rotation of the output shaft 51 is transmitted to the front wheels 2 via the gear 65, the gear 66, the transmission shaft 61, the gear 64, the quick turn device 75, the differential gear 17, and the like. . Thereby, the tractor 1 is driven to travel.

  Next, the hydraulic control device 90 related to the main transmission 20 and the main clutch 30 of the tractor 1 will be described.

  As shown in FIG. 3, the pressure oil discharged from the oil pump 91 is used for traveling operation, and is supplied to a hydraulic control device 90 that controls the main transmission 20 and the main clutch 30 with hydraulic pressure via a check valve 92. Supplied.

  The temperature and pressure of the pressure oil flowing into the hydraulic control device 90 is detected by the oil temperature sensor 93 and the hydraulic sensor 94 and fed back to the electrical control device 100 described later. Further, the filters 95 and 97 are disposed between the check valve 92 and the hydraulic sensor 94.

  Part of the pressure oil that has passed through the filter 95 is supplied to the proportional pressure control solenoid valve 96. The proportional pressure control solenoid valve 96 is regulated by an electric signal operation, and the regulated pressure oil is sent to the main clutch 30 via the filter 101 and the shuttle valve 102, and is connected to the front main transmission 20A. A forward / reverse switching device 40 is connected.

  The solenoid valve 111 controls the hydraulic actuator 112 for displacing the position of the shift member 27 of the rear main transmission 20B. The shift piston 113 of the hydraulic actuator 112 is expanded and contracted by the pressure oil supplied from the solenoid valve 111, and the stop position is held by the pin 115. The check valve 117 is released when the shift piston 113 moves and the pin 115 moves from the notch portion of the shift piston 113 to the shaft portion, and the hydraulic pressure supplied to the main clutch 30 is reduced to reduce the pressure of the main clutch 30. Perform cutting operation

  The solenoid valve 121 and the solenoid valve 122 control the hydraulic actuator 123 for displacing the position of the shift member 23 of the front main transmission 20A. The shift piston 125 of the hydraulic actuator 123 expands and contracts by the pressure oil supplied from the solenoid valves 121 and 122, and the stop position is held by the pin 126. The check valve 127 is released when the shift piston 125 moves and the pin 126 moves from the notch portion of the shift piston 125 to the shaft portion, and the hydraulic pressure supplied to the main clutch 30 is reduced to reduce the pressure of the main clutch 30. Perform the cutting operation.

  The solenoid valve 131 and the solenoid valve 132 control the hydraulic actuator 133 for displacing the position of the shift member 25 of the front main transmission 20A. The shift piston 135 of the hydraulic actuator 133 expands and contracts by the pressure oil supplied from the solenoid valves 131 and 132, and the stop position is held by the pin 136. The check valve 137 is released when the shift piston 135 moves and the pin 136 moves from the notch portion of the shift piston 135 to the shaft portion. The check valve 137 reduces the hydraulic pressure supplied to the main clutch 30 to reduce the pressure of the main clutch 30. Perform the cutting operation.

  In the front main transmission 20A, when the pin 126 or the pin 136 is engaged with any one of the notches of the shift pistons 125 and 135 that move the shift members 23 and 25, the front main transmission 20A. Shifting with the transmission 20A is completed. Further, the shift member 23 cannot be engaged with the gear 22a or the gear 22b and the shift member 25 cannot be engaged with the gear 22c or the gear 22d at the same time. Accordingly, the check valves 127 and 137 are connected in series so that the main clutch 30 is engaged when the pin 126 or the pin 136 is engaged with any one of the notches of the shift pistons 125 and 135. It is connected. Reference numeral 141 shown in FIG. 3 is a solenoid valve that controls the hydraulic actuator 142 for displacing the position of the shift member 47 of the forward / reverse switching device 40.

  Next, the operation of the hydraulic control device 90 will be described.

  When pressure oil is supplied from the solenoid valve 111 to the hydraulic actuator 112 based on a speed change operation of the main speed change operation tool 153 described later, the shift piston 113 extends, and the shift member 27 of the rear main speed change device 20B is connected to the transmission shaft 45. Move along. Thereby, for example, when the shift piston 113 of the hydraulic actuator 112 is in the extended position, the shift member 27 of the rear main transmission 20B is engaged with the gear 26a, and when the shift piston 113 is in the tightening position, the shift member 27 is Position so as to mesh with the gear 26b.

  Further, when pressure oil is supplied from the solenoid valve 121 to the hydraulic actuator 123 based on the speed change operation of the main speed change operation tool 153, the shift piston 125 extends, and pressure oil is supplied from the solenoid valve 122 to the hydraulic actuator 123. Then, the shift piston 125 contracts, and the shift member 23 of the front main transmission 20A is moved along the transmission shaft 21. Thus, for example, when the shift piston 125 of the hydraulic actuator 123 is in the extended position, the shift member 23 of the front main transmission 20A is engaged with the gear 22a, and when the shift piston 125 is in the contracted position, the shift member 23 is It meshes with the gear 22b. As shown in FIG. 3, when the shift piston 125 is in the intermediate position, the shift member 23 is positioned at a neutral position that does not mesh with the gears 22a and 22b.

  Further, when pressure oil is supplied from the solenoid valve 131 to the hydraulic actuator 133 based on the speed change operation of the main speed change operation tool 153, the shift piston 135 extends, and pressure oil is supplied from the solenoid valve 132 to the hydraulic actuator 133. Then, the shift piston 135 contracts, and the shift member 25 of the front main transmission 20A is moved along the transmission shaft 21. Thereby, for example, when the shift piston 135 of the hydraulic actuator 133 is in the extended position, the shift member 25 of the front main transmission 20A is engaged with the gear 22c, and when the shift piston 135 is in the contracted position, the shift member 25 is It meshes with the gear 22d. As shown in FIG. 3, when the shift piston 135 is in the intermediate position, the shift member 25 is positioned at a neutral position that does not mesh with the gears 22c and 22d.

  As shown in FIG. 4, the control device (shift control device) 100 has a first speed solenoid valve 122, a second speed solenoid valve 121, a third speed solenoid valve 132, a fourth speed solenoid valve 131, and a high / low speed change solenoid valve 111 on the output side. The forward / reverse switching solenoid valve 141, the proportional pressure control solenoid valve 96, and the storage device M are connected. Further, on the input side of the control device 100, a shift-up switch (acceleration switch) SW1, a shift-down switch (deceleration switch) SW2, an engine rotation sensor 105, an axle rotation sensor 106, a hydraulic sensor 94, an oil temperature sensor 93, front and rear The advance sensor 107, the main clutch sensor 108, and the auxiliary transmission sensor 109 (the high speed sensor 109a and the low speed sensor 109b) are connected. The storage device M is a non-volatile storage device that can retain the stored contents even when the key switch that is the main power switch of the tractor 1 is turned off. For example, the storage device M may be configured by an EEPROM, a flash memory, a hard disk, or the like. it can.

  When the control device 100 is activated in response to a key switch input operation, the upshift switch SW1, the downshift switch SW2, the engine rotation sensor 105, the axle rotation sensor 106, the hydraulic pressure sensor 94, the oil temperature sensor 93, and the forward / backward movement sensor. 107, a first speed solenoid valve 122, a second speed solenoid valve 121, a third speed solenoid valve 132, and a fourth speed solenoid valve 131 based on signals from the main clutch sensor 108 and the auxiliary transmission sensor 109 (high speed sensor 109a, low speed sensor 109b). The operation of the high / low speed shifting solenoid valve 111, the forward / reverse switching solenoid valve 141, the proportional pressure control solenoid valve 96 and the storage device M is controlled. Thereby, the switching operation of the shift member 23 and the shift member 25 of the front main transmission 20A, the shift member 27 of the rear main transmission 20B, the main clutch 30 and the like is performed, and the shift operation of the main transmission 20 and the main clutch 30 are performed. The on / off operation is performed. For example, by controlling the operations of the first speed solenoid valve 122, the second speed solenoid valve 121, the third speed solenoid valve 132, the fourth speed solenoid valve 131, and the high / low speed solenoid valve 111 in a combination as shown in FIG. The main shift operation is performed.

  Next, the auxiliary transmission lever 150 for mechanically changing the auxiliary transmission device 50 will be described with reference to FIG.

  As shown in FIG. 1, the auxiliary transmission lever 150 is provided on the left side of the driver's seat 8 of the tractor 1, and as shown in FIG. The shaft portion 151 is supported by the shaft portion 151 and the grip portion 152 is provided at the upper end portion of the shaft portion 151. The grip portion 152 is shaped so that the top portion can be easily gripped, and the operator can hold the top portion of the grip portion 152 while moving the sub transmission device 50 while moving the sub transmission lever 150 in the front-rear direction or the left-right direction. To operate. The auxiliary transmission lever 150 of the present embodiment is mechanically linked to the shift member 52 of the auxiliary transmission device 50 so that the auxiliary transmission device 50 can be operated. Alternatively, the shift stage of the sub-transmission device 50 can be recognized on the control device 100 side by detecting the sub-transmission sensor 109 (the high speed sensor 109a and the low speed sensor 109b).

  A shift-up switch SW1 and a shift-down switch SW2 for shifting the main transmission 20 are housed in the grip portion 152 of the auxiliary transmission lever 150. The shift-up switch SW1 and the shift-down switch SW2 are both turned on and activated in accordance with the operation of the main transmission operating tool 153.

  The main transmission operating tool 153 of the present embodiment is a dial-type operating tool that is rotatable about a support shaft (not shown) extending in the left-right direction, and is provided on a side surface of the grip portion 152 on the inward side. ing. A cam plate (not shown) is integrally fixed to the support shaft, and when the main transmission operating tool 153 is rotated to the front side of the machine body, the cam plate is integrally rotated in the same direction to shift up switch SW1. When the main transmission operating tool 153 is rotated to the rear side of the machine body, the cam plate is integrally rotated in the same direction to operate the shift down switch SW2.

  In the present embodiment, the main transmission operation tool 153 is urged toward the neutral position, and every time the upshift switch SW1 or the downshift switch SW2 is turned on and operated according to the rotation operation of the main transmission operation tool 153. The main transmission 20 is shifted one step at a time for increasing or decreasing the speed. As a result, the main transmission 20 is shifted step by step to the speed increasing side or the speed reducing side to obtain a desired traveling speed.

  Next, a characteristic configuration of the present invention will be described.

  As described above, the tractor 1 according to the present invention is activated in response to the operation of the key switch and the main transmission 20 that performs a traveling shift according to the operation of the actuator, and the actuator according to the artificial acceleration / deceleration command. A working vehicle including a control device 100 that shifts the main transmission 20 by operation control, and the speed control device 100 stores a current shift speed of the main transmission 20 in the storage device M. Means and an initial setting means for determining an initial gear position of the main transmission 20 when the key switch is switched from the off state to the on state. The initial setting means stores the speed change stored before the key switch is turned off. Regardless of whether the gear is the initial gear and whether the gear is stored before the key switch is turned off, a preset predetermined gear can be selected as the initial gear. Select the shift key switch is adapted to determine based on the stored shift speed before the cut.

  In this way, when setting the initial gear position of the main transmission 20 according to the key switch-on operation, an appropriate gear position can be set according to the situation. Specifically, when the shift speed stored before the key switch is turned off is the low speed shift speed (1st to 4th speed), there is no fear of sudden start or engine stall. Is set to the initial shift speed, so that the work can be resumed promptly. Also, when the shift speed stored before the key switch is turned off is the high speed shift speed (5-speed to 8-speed). Regardless of the memorized shift speed, a sudden shift or engine stall can be prevented by setting a predetermined shift speed (5th speed: low speed gear on the high speed side) as the initial shift speed.

  Further, as described above, the tractor 1 of the present invention includes a main transmission 20 that performs a traveling shift according to the operation of the actuator, a sub-transmission 50 that is mechanically operated according to a manual operation, A working traveling vehicle that includes a control device 100 that is activated in response to an operation of turning on a key switch and that shifts the main transmission 20 by operating an actuator according to an artificial acceleration / deceleration command. Is an initial stage for determining an initial shift stage of the main transmission 20 when the key switch is switched from the OFF state to the ON state, and the shift stage storing means for storing the current shift stage of the main transmission 20 and the auxiliary transmission 50 Setting means, wherein the initial setting means relates to the shift stage stored before the key switch is turned off as the initial shift stage and the shift stage stored before the key switch is turned off. It is possible to select a preset predetermined shift speed as the initial shift speed, and which one is selected depends on whether or not the shift speed of the auxiliary transmission 50 is changed while the key switch is turned off. Judgment is based on this.

  In this way, when setting the initial gear position of the main transmission 20 according to the key switch-on operation, an appropriate gear position can be set according to the situation. Specifically, when the shift stage of the auxiliary transmission 50 is changed to the high speed side while the key switch is turned off, a predetermined value set in advance regardless of the shift stage stored before the key switch is turned off. By making the first gear (the first gear: the lowest gear) the initial gear, it is possible to prevent sudden start and engine stall. In addition, when the shift stage of the sub-transmission device 50 is changed to the low speed side while the key switch is in the off state, a predetermined shift stage that is set in advance regardless of the shift stage that is stored before the key switch is turned off. (8th speed: highest speed stage) can be set as the initial shift stage.

  Next, specific examples of shift control and initial setting by the control device 100 will be described with reference to FIGS.

  As shown in FIG. 7, in the shift control, it is determined whether or not the shift speed of the auxiliary transmission 50 is changed (S101). If the determination result is NO, the shift-up switch SW1 and the shift-down switch SW2 are turned on. Judgment is made (S102, S103). Here, when the shift-up switch SW1 is turned on and operated, the gear position (shift speed setting variable of the main transmission 20) is increased by one step (S104), and when the shift-down switch SW2 is operated and operated, the gear position is changed. Decrease by one step (S105). Further, when the shift speed of the auxiliary transmission 50 is changed, it is determined whether or not the shift speed is changed to the high speed side (S106). If the determination result is YES, the shift speed is set to the lowest speed (first speed). (S107), in the case of NO, the gear position is set to the highest speed (8th gear) (S108). When these shift speed changing processes are executed, the shift speeds of the main transmission 20 and the auxiliary transmission 50 are stored (S109: shift speed storage means), and then the main clutch 30 is disconnected by controlling the solenoid valve described above. At the same time (S110), each shifter member of the main transmission 20 is operated according to the changed gear position (S111), and the completion of the shift is determined (S112). Thereafter, the pressure applied to the main clutch 30 is increased (S113), and one shift operation is completed.

  The initial setting (initial setting means) shown in FIG. 8 is a process for determining the initial gear position of the main transmission 20 when the key switch is switched from the OFF state to the ON state. The current gear position of the main transmission 20 and the auxiliary transmission 50 and the current gear position of the main transmission 20 and the auxiliary transmission 50 are read (S201). Next, based on the comparison between the shift speed of the auxiliary transmission 50 stored in the storage device M and the current shift speed of the auxiliary transmission 50, the shift of the auxiliary transmission 50 is performed while the key switch is turned off. It is determined whether or not the gear position has been changed (S202). If the determination result is NO, the gear position of the main transmission 20 stored before the key switch is turned off is on the high speed side (5-speed to 8-speed). It is determined whether or not there is (S203). If this determination result is also NO, the shift stage stored before the key switch is turned off is set as the initial shift stage (S204). If YES is determined, the shift stage is stored before the key switch is turned off. Regardless of the gear position, the low speed gear (5th gear) on the high speed side is set as the initial gear (S205). Further, when it is determined that the shift stage of the auxiliary transmission 50 has been changed while the key switch is turned off, it is determined whether or not the shift is to the high speed side (S206). If the determination result is YES, The lowest gear (first gear) is set as the initial gear (S207). If NO, the highest gear (eighth) is set as the initial gear (S208).

  According to the present embodiment configured as described, the main transmission 20 that performs a traveling shift in accordance with the operation of the actuator, and the actuator that is activated in response to a key switch on operation and that responds to an artificial acceleration / deceleration command In the tractor 1 including the control device 100 that shifts the main transmission 20 by the operation control of the control device, the control device 100 includes a shift speed storage unit that stores the current shift speed of the main transmission 20 and the key switch is turned off. And an initial setting means for determining an initial gear position of the main transmission 20 when the gear shifts to the on state. The initial setting means sets the gear position stored before the key switch is turned off as the initial gear position. Regardless of the shift speed stored before the key switch is turned off, it is possible to select a preset predetermined shift speed as the initial shift speed. Is determined based on the gear position stored before the key switch is turned off. Therefore, when setting the initial gear position of the main transmission 20 according to the key switch on / off operation, an appropriate gear speed is selected according to the situation. A stage can be set. For example, when the shift stage stored before the key switch is turned off is a low speed shift stage, there is no fear of sudden start or engine stall, so by setting the stored shift stage as the initial shift stage, It is possible to resume the work promptly, and when the shift speed stored before the key switch is turned off is the high speed shift speed, the predetermined shift speed set in advance is set regardless of the stored shift speed. By setting the initial gear position, sudden start and engine stall can be prevented.

  Further, in the present embodiment, the main transmission 20 that performs a traveling shift according to the operation of the actuator, the auxiliary transmission 50 that is mechanically shifted according to an artificial operation, and a key switch input operation. In the tractor 1, the control device 100 includes the main transmission device 20 and the subtransmission device 50. The control device 100 includes the control device 100 that shifts the main transmission device 20 according to an artificial operation control according to an artificial acceleration / deceleration command. Shift stage storing means for storing the current shift stage, and initial setting means for determining an initial shift stage of the main transmission 20 when the key switch is switched from the OFF state to the ON state. Regardless of whether the shift stage stored before the key switch is turned off is set as the initial shift stage and the shift stage stored before the key switch is turned off, a predetermined change set in advance. It is possible to select the initial gear position, and which one to select is determined based on whether or not the gear position of the sub-transmission device 50 has been changed while the key switch is off. In setting the initial gear position of the main transmission 20 according to the key switch on operation, an appropriate gear position can be set according to the situation. For example, if the shift stage of the auxiliary transmission 50 is changed to the high speed side while the key switch is turned off, the preset low speed side shift is performed regardless of the speed stage stored before the key switch is turned off. By setting the gear to the initial gear, it is possible to prevent sudden start and engine stall.

It is a top view of a tractor. It is a transmission circuit diagram which shows the transmission structure of a tractor. It is a hydraulic circuit diagram which shows the hydraulic control structure of a tractor. It is a block diagram which shows the electric control structure of a tractor. It is explanatory drawing which shows the transmission pattern of a main transmission. It is a side view of an auxiliary transmission lever. It is a flowchart which shows the process sequence of the shift control in a control apparatus. It is a flowchart which shows the process sequence of the initial setting in a control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tractor 5 Traveling machine body 20 Main transmission device 30 Main clutch 40 Forward / reverse switching device 50 Sub transmission device 100 Control device 150 Sub transmission lever 153 Main transmission operation tool SW1 Shift up switch SW2 Shift down switch

Claims (2)

A traveling main transmission that performs a traveling shift according to the operation of the actuator;
In a working traveling vehicle comprising: a shift control device that is activated in response to an operation of turning on a key switch, and that shifts a travel main transmission by operating an actuator according to an artificial acceleration / deceleration command.
The shift control device includes:
Shift speed storage means for storing the current shift speed of the main driving transmission;
An initial setting means for determining an initial gear position of the traveling main transmission when the key switch is switched from the off state to the on state;
The initial setting means includes:
If the gear position stored before the key switch is turned off is the low speed gear stage, the memorized gear stage is selected as the initial gear stage, and the gear stage stored before the key switch is turned off is In this case, the working vehicle is configured to select a predetermined low-speed gear position as an initial gear speed regardless of the stored gear speed . A traveling main transmission that performs a traveling shift according to the operation of the actuator;
A traveling sub-transmission that is mechanically shifted in response to an artificial operation;
In a working traveling vehicle comprising: a shift control device that is activated in response to an operation of turning on a key switch, and that shifts a travel main transmission by operating an actuator according to an artificial acceleration / deceleration command.
The shift control device includes:
If the gear position of the traveling sub-transmission device is changed to the high speed side while the key switch is in the off state, the preset low speed stage is selected as the initial gear position, and the vehicle travels while the key switch is in the off state. A working vehicle configured to select a predetermined high speed as an initial speed when the speed of the auxiliary transmission is changed to a low speed .

Images