JP2010203572A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the erroneous operation of an electric actuator for gear shifting when a starter is driven, in a working vehicle equipped with a control device carrying out the actuation control of the electric actuator for gear shifting actuating an output adjusting member of an HST according to the operation of a gear shift operating member. <P>SOLUTION: The control device in the working vehicle is constituted to carry out the on/off switching control of a main power supply and the on/off switching control of a starter on the basis of signals from a main power supply/starter sensor detecting an operation state of a main operating member, and execute vehicle speed control carrying out the actuation control of the electric actuator for gear shifting on the basis of signals from a gear shift operation side sensor and a gear shift actuation side sensor. The control device starts the vehicle speed control according to operation from a main power supply turning-off position to a main power turning-on position of the main operating member, and prohibits the actuation control of the electric actuator for gear shifting while the starter is turned on. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes an HST inserted in a traveling system transmission path from an engine to a traveling unit, an electric actuator for shifting that operates an output adjusting member of the HST, and a control device that controls the operation of the electric actuator for shifting. The present invention relates to a working vehicle such as a snowplow having

  HST inserted in a traveling system transmission path from the engine to the traveling unit, a shift electric actuator that operates the output adjustment member of the HST, and a control device that controls the operation of the shift electric actuator, There has been proposed a working vehicle in the form of a snowplow in which the control device controls the operation of the electric actuator for shifting so that the HST outputs rotational power corresponding to the operation of the shifting operation member ( For example, see Patent Document 1 below).

  Specifically, the working vehicle includes a shift operation side sensor that detects an operation state of the shift operation member, in addition to the engine, the traveling unit, the HST, the shift operation member, and the shift electric actuator, and the shift operation. A shift operation side sensor for directly or indirectly detecting an operation state of the electric actuator for electric power, a generator for generating electric power by rotational power from the engine, and storing the electric power generated by the generator and including the sensor The battery acting as a power source of an electric device, a starter for starting the engine, a main operation member for turning on / off a main power source and turning on / off the starter, and an operation state of the main operation member Main power / starter sensor for detecting the main power and on / off switching of the main power based on a signal from the main power / starter sensor And a control device for performing on / off switching control of the starter and a vehicle speed control for controlling the operation of the shift electric actuator based on signals from the shift operation side sensor and the shift operation side sensor. ing.

  By the way, the main operation member is configured to be able to take a main power off position, a main power on position, and a starter operating position, and the control device starts the vehicle speed control when the main power is turned on. Therefore, there are the following inconveniences.

  That is, when the main operation member is operated from the main power off position to the main power off position, the control device turns on the main power and starts vehicle speed control. When the main operation member is operated from the main power off position to the starter operating position, the control device drives the starter to start the engine.

By the way, the control device executes control including the vehicle speed control based on a reference voltage using electric power supplied from the battery.
However, since the battery is also used as a power source for the starter, the voltage of the battery drops when the starter is driven.

  In other words, when the starter is driven, the control device executes the vehicle speed control with a reference voltage lowered. For example, the control device does not control the control even though the shift operation member is positioned at a neutral position. There is a possibility that the apparatus operates the electric actuator for shifting to the forward side.

JP 2008-055924 A

  The present invention has been made in view of the above prior art, and in a work vehicle provided with a control device that controls the operation of an electric actuator for shifting that operates an output adjusting member of an HST in accordance with an operation of the shifting operation member. An object of the present invention is to provide a work vehicle that can prevent malfunction of the electric actuator for shifting during driving.

  In order to achieve the above object, the present invention provides an engine, a traveling unit, an HST interposed in a traveling system transmission path from the engine to the traveling unit, a manually operated speed change operation member, and the HST. A shift electric actuator that operates the output adjusting member, a shift operation side sensor that detects an operation state of the shift operation member, and a shift operation side sensor that directly or indirectly detects the operation state of the shift electric actuator; A generator that generates electric power by rotational power from the engine, a battery that is charged by the generator, a starter that starts the engine by using electric power from the battery, a main power off position, and a main power on A main operation member that can be manually operated that can take a position and a starter operating position, and a main power source / starter that detects an operation state of the main operation member And on / off switching control of the main power source and on / off switching control of the starter based on the signal from the sensor and the main power source / starter sensor, and the signals from the shift operation side sensor and the shift operation side sensor And a control device for performing vehicle speed control for controlling the operation of the electric actuator for shifting based on the control device, wherein the control device operates the main operation member from a main power off position to a main power on position. Accordingly, there is provided a work vehicle configured to start the vehicle speed control in response to the control and to prohibit the operation control of the shift electric actuator while the starter is in an ON state.

  Preferably, in the vehicle speed control, the control device exceeds a predetermined dead band range between a shift operation state based on a signal from the shift operation side sensor and a shift operation state based on a signal from the shift operation side sensor. If a deviation occurs, a control signal having a pulse width corresponding to the magnitude of the deviation is output to the shift electric motor. In such a configuration, the control device is configured to output a control signal having a pulse width of zero to the electric actuator for shifting while the starter is in the ON state.

  Preferably, the control device does not drive the starter when the main operation member is operated from the main power-on position to the starter operation position in a state where the speed change operation member is located at a position other than the neutral position. Configured.

In the work vehicle according to the present invention, the control device includes a shift electric actuator based on signals from the shift operation side sensor and the shift operation side sensor in response to an operation of the main operation member from the main power supply off position to the main power supply on position. While the vehicle speed control is being executed, the operation control of the shifting electric actuator is prohibited while the starter is in an on state even when the vehicle speed control is being executed. .
Therefore, it is possible to effectively prevent the shifting electric actuator from being erroneously operated due to the battery voltage drop during the starter driving.
Furthermore, it is possible to prevent the starter and the shifting electric actuator from being operated at the same time, and to prevent the battery voltage from being lowered as much as possible.

FIG. 1 is a schematic side view of a working vehicle according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the working vehicle shown in FIG. FIG. 3 is a transmission schematic diagram of the working vehicle shown in FIGS. 1 and 2. FIG. 4 is a system block diagram of the control device in the working vehicle shown in FIGS. FIG. 5 is a flowchart of a control program stored in the control device.

Hereinafter, an embodiment of a working vehicle according to the present invention will be described with reference to the accompanying drawings.
1 to 3 are a schematic side view, a schematic plan view, and a transmission schematic diagram, respectively, of the working vehicle 1 according to the present embodiment.

As shown in FIGS. 1 and 2, the working vehicle 1 according to the present embodiment is in the form of a walking snowplow.
Specifically, the working vehicle 1 includes a body frame 10, an engine 20 supported by the body frame 10, a pair of left and right traveling units 30L and 30R, a front side of the body frame 10, and the engine. A working unit 40 driven by the rotational power from 20, a transmission 50 inserted in a transmission path from the engine 20 to the traveling units 30L, 30R, and an operation disposed on the rear side of the body frame 10 Part 70.

  In the working vehicle 1 in the form of the snow remover, the working unit 40 is a snow removing unit that collects and discharges snow on the traveling road surface.

  Specifically, as shown in FIGS. 1 to 3, the working unit 40 includes a scraping auger 41 disposed on the front side of the machine body frame 10 and an auger housing 42 surrounding the scraping auger 41. And a blower housing 43 extending rearward in communication with the auger housing 42, a blower 44 built in the blower housing 43, and a shooter 45 disposed above the blower 44.

The scraping auger 41 is rotationally driven around the rotational axis along the body width direction by the rotational power transmitted from the engine 20, and collects snow on the travel path in the center of the body width direction to collect the snow inside the blower housing 43. It is configured to send toward the blower 44.
Specifically, the auger auger 41 is operatively connected to the engine 20 and is supported by the auger drive shaft 41a supported by the auger housing 42 so as to be rotatable about the axis line along the body width direction. And a protrusion 41b provided in a spiral shape on the outer peripheral surface of the drive shaft 41a.

The auger housing 42 surrounds the raking auger 41 with the front lower part opened.
The blower housing 43 accommodates the blower 44 in a state where the base end side is connected to the body frame 10 and the distal end side is connected to the auger housing 42.

  The blower 44 is driven by the rotational power transmitted from the engine 20, and is configured to jump the snow transported from the scraping auger 41 into the blower housing 43 toward the shooter 45. .

The shooter 45 acts as a discharge guide for snow blown by the blower 44.
Specifically, the shooter 45 is a cylindrical member whose base end is connected to the blower housing 43.
In the present embodiment, the shooter 45 is connected to the upper surface of the blower housing 43 so as to be rotatable about a rotation axis along a substantially vertical direction, and in a substantially horizontal direction with respect to the proximal end member. And a tip end side member connected to be rotatable about a rotation axis along the direction of the axis, and a discharge direction and a discharge angle of the snow discharged through the shooter 45 can be adjusted.

As shown in FIG. 3, the working unit 40 receives rotational power from the engine 20 via a work machine transmission mechanism 100.
Specifically, as shown in FIGS. 1 and 2, the engine 20 includes an engine body 21 supported by the body frame 10 behind the working unit 40, and an engine output projecting forward from the engine body 21. And a shaft 22.
The work machine transmission mechanism 100 operatively connects the engine output shaft 22 and the input shaft 40a of the working unit 40.

In the present embodiment, the work machine transmission mechanism 100 is a pulley / belt transmission mechanism as shown in FIGS.
Specifically, as shown in FIGS. 1 and 3, the work machine transmission mechanism 100 includes a work machine drive pulley 101 supported on the engine output shaft 22 so as not to rotate relative to the engine output shaft 22, and an input of the work machine 40. It has a work machine driven pulley 102 supported by a shaft 40a so as not to rotate relative to the shaft 40a, and a work machine endless belt 103 wound around the drive and driven pulleys 101 and 102.

  In the present embodiment, as shown in FIG. 1, the engine output shaft 22 is supported by a bracket 11 connected to the body frame 10 at an intermediate portion via a bearing (not shown), The work machine drive pulley 101 is supported by a portion of the engine output shaft 22 that is located on the front side of the bracket 11.

Furthermore, as shown in FIGS. 1 and 3, the work vehicle 1 according to the present embodiment includes a work clutch mechanism 105 that selectively engages and disengages the transmission state of the work machine transmission mechanism 100.
The work clutch mechanism 105 is disposed, for example, between the engine output shaft 22 and the work machine system drive side pulley 101, and the work machine system drive side pulley 101 is rotated relative to the engine output shaft 22. The clutch engaged state to be disabled and the clutch disengaged state in which the work machine drive side pulley 101 is rotatable relative to the engine output shaft 22 are configured.

The transmission 50 is supported by the body frame 10 on the rear side of the engine 20.
As shown in FIGS. 1 to 3, the transmission 50 includes a HST 510 for continuously changing the rotational power from the engine 20, a pair of left and right electric motors for turning 520 </ b> L and 520 </ b> R, a running rotational power from the HST 510, and A pair of left and right differential mechanisms 530L and 530R that synthesize and output the turning rotational power from the corresponding turning electric motors 520L and 520R to the corresponding traveling units 30L and 30R, and the differential mechanisms 503L and 530R. And a mission case 550 that accommodates.

  As shown in FIG. 3, the HST 510 includes a pump shaft 511 operatively connected to the engine 20, a hydraulic pump 512 supported by the pump shaft 511 so as not to rotate relatively, and a pair of HST lines connected to the hydraulic pump 512. Hydraulic motor 514 fluidly connected via 519, a motor shaft 513 that supports the hydraulic motor 514 in a relatively non-rotatable manner, and at least one of the hydraulic pump 512 and the hydraulic motor 514 that is a variable displacement type (this In the embodiment, the hydraulic pump 512 includes an output adjusting member 515 that changes the suction / discharge amount and the suction / discharge direction of a variable volume member.

  In the present embodiment, the HST 510 is supported on the rear end surface of the transmission case 550, and the pump shaft 511 includes a traveling system transmission shaft 115 and a traveling system first transmission mechanism that extend forward from the transmission case 550. The engine output shaft 22 is operatively connected through 110.

Specifically, the transmission case 115 that has a rear end connected to the pump shaft 511 so as not to rotate relatively around the axis and a front end extended forward from the transmission case 550 is supported by the transmission case 550. Has been.
As shown in FIG. 1, the traveling system transmission shaft 115 has a front end supported by the bracket 11.

The traveling system first transmission mechanism 110 operatively connects the engine output shaft 22 and the traveling system transmission shaft 115.
In the present embodiment, as shown in FIGS. 1 and 3, the traveling system first transmission mechanism 110 is a pulley / belt transmission mechanism.

Specifically, as shown in FIGS. 1 and 3, the traveling system first transmission mechanism 110 includes a traveling system drive pulley 111 that is supported on the engine output shaft 22 so as not to be relatively rotatable, and the traveling system transmission shaft 115. And a traveling system driven pulley 112 supported so as not to rotate relative to the driving system, and a traveling system endless belt 113 wound around the driving and driven pulleys 111 and 112.
In the present embodiment, the traveling system drive pulley 111 is supported by a portion of the engine output shaft 22 located on the rear side of the bracket 11 as shown in FIG.

In the present embodiment, the hydraulic pump 512 and the hydraulic motor 514 are of an axial piston type.
Therefore, the output adjusting member 515 is movable to change the suction / discharge amount and the suction / discharge direction of the variable volume member (the hydraulic pump 512 in the present embodiment) according to the tilt position around the swing axis. A swash plate (not shown) and a control shaft 515a (see FIG. 2) connected to the movable swash plate so that the movable swash plate tilts around the swing shaft in response to rotation about its own axis. ).
Note that reference numeral 515b in FIG. 2 denotes a control arm supported on the control shaft 515a so as not to be relatively rotatable.

The output adjusting member 515 operates as follows.
When the movable swash plate is positioned at a neutral position around the swing axis, the hydraulic pump 512 does not discharge pressure oil even when the pump shaft 511 is driven to rotate about the axis, and therefore the hydraulic motor 514 And the HST neutral state where the rotation of the motor shaft 513 is stopped appears.

When the movable swash plate is tilted from the neutral position to one side around the swing axis, the hydraulic pump 512 is set to the tilt angle of the movable swash plate in a direction corresponding to the tilt direction of the movable swash plate. A corresponding amount of pressure oil is discharged, so that the hydraulic motor 514 and the motor shaft 513 correspond to the tilt angle of the movable swash plate in the first rotation direction corresponding to the tilt direction of the movable swash plate. It rotates at the rotation speed.
That is, when the movable swash plate is tilted from the neutral position to one side around the swing shaft, the motor shaft 513 moves in one of the vehicle forward direction and the vehicle reverse direction (for example, the forward direction). Rotates at a rotation speed according to the tilt angle.

When the movable swash plate is tilted from the neutral position to the other side around the swing shaft, the hydraulic pump 512 is set to the tilt angle of the movable swash plate in a direction corresponding to the tilt direction of the movable swash plate. A corresponding amount of pressure oil is discharged, whereby the hydraulic motor 514 and the motor shaft 513 correspond to the tilt angle of the movable swash plate in the second rotation direction according to the tilt direction of the movable swash plate. It rotates at the rotation speed.
That is, when the movable swash plate is tilted from the neutral position to the other side around the swinging shaft, the motor shaft 513 is moved in the other of the vehicle forward direction and the vehicle reverse direction (for example, the reverse direction). Rotates at a rotation speed according to the tilt angle.

Next, the pair of left and right differential mechanisms 530L and 530R will be described.
The pair of left and right differential mechanisms 530L and 530R are symmetrical with respect to each other with respect to the center plane in the longitudinal direction of the working vehicle 1.
Accordingly, in the drawing, the same reference numerals with the last letters L and R are used for the components of the left differential mechanism 530L and the right differential mechanism 530R, respectively.

  The left differential mechanism 530L corresponds to a first element that operatively inputs rotational power from the HST 510 and a second element that operatively inputs rotational power from the corresponding left turning electric motor 520L. And a third element that outputs rotational power to the left traveling unit 30L.

  Similarly, the right differential mechanism 530R includes a first element that operatively inputs rotational power from the HST 510, and a second element that operatively inputs rotational power from the corresponding right turning electric motor 520R. And a third element that outputs rotational power to the corresponding right traveling unit 30R.

  In the work vehicle 1 having such a configuration, the rotational power input from the electric motors 520L and 520R to the second elements of the corresponding differential mechanisms 530L and 530R is used as the braking rotational power for turning. Works. That is, by inputting rotational power from the left and right turning electric motors 520L, 520R to the corresponding second elements of the differential mechanisms 530L, 530R, the first pair of left and right differential mechanisms 530L, 530R A rotational speed difference is generated between the three elements, and thereby the left or right turn of the working vehicle 1 appears.

  In the present embodiment, as shown in FIG. 3, the sun gear 531L (531R), the ring gear 535L (535R) and the carrier 534L (534R) act as the first to third elements, respectively.

  That is, the differential mechanism 30L (30R) revolves around the sun gear 531L (531R) operatively connected to the motor shaft 513 of the HST 510 and the sun gear 531L (531R). The planetary gear 532L (532R) meshing with the 531R) and the planetary gear 532L (532R) so as to be relatively rotatable and revolving around the sun gear 531L (531R) according to the revolution of the planetary gear 532L (532R). A carrier 534L (534R) and the ring gear 535L (535R) having internal teeth meshing with the planetary gear 532L (532R) and operatively connected to the corresponding electric motor 520L (520R) corresponding to the outer peripheral surface. I have.

  In the present embodiment, the sun gear 531L (531R) is operatively connected to the motor shaft 513 via the traveling system second transmission mechanism 120 housed in the mission case 550.

  Specifically, as shown in FIG. 3, the traveling system second transmission mechanism 120 includes a first transmission shaft 121 accommodated in the transmission case 550 along the body width direction, and both end portions along the body width direction. A second transmission shaft 125 in which the sun gears of the pair of left and right differential mechanisms are supported so as not to rotate relative to each other; an upstream transmission mechanism 122 that operatively connects the motor shaft 513 and the first transmission shaft 121; And a downstream transmission mechanism 126 that operatively connects the first and second transmission shafts 121 and 125.

In the present embodiment, the motor shaft 513 is along the vehicle longitudinal direction.
Therefore, the upstream transmission mechanism 122 is engaged with the drive side bevel gear 122a, which is supported on the end of the motor shaft 513 that is inserted into the transmission case 550 so as not to be relatively rotatable, and the drive side bevel gear 122a. And a driven bevel gear 122b supported by the first transmission shaft 121 so as not to rotate relative to the first transmission shaft 121.
The drive-side bevel gear 122a has a small diameter and the driven-side bevel gear 122b has a large diameter so that rotational power is transmitted from the motor shaft 513 to the first transmission shaft 121 at a reduced speed.

The downstream transmission mechanism 126 includes a drive-side sprocket 126a supported so as not to rotate relative to the first transmission shaft 121, a driven-side sprocket 126b supported so as not to rotate relative to the second transmission shaft 125, and the drive. A side sprocket 126a and a chain 126c wound around the driven side sprocket 126b.
The driving side sprocket 126a has a small diameter and the driven side sprocket 126b has a large diameter so that rotational power is transmitted from the first transmission shaft 121 to the second transmission shaft 125 at a reduced speed.

Preferably, a brake mechanism 130 that can selectively apply a braking force to a transmission path from the motor shaft 513 to the sun gears 531L and 531R of the pair of left and right differential mechanisms 530L and 530R is provided.
In the present embodiment, as shown in FIG. 3, the brake mechanism 130 is configured to selectively apply a braking force to the first transmission shaft 121.

In the present embodiment, the ring gear 535L (535R) is operatively connected to the output shaft 522L (522R) of the corresponding electric motor 520L (520R) for turning.
Specifically, the pair of left and right electric motors 520L and 520R for turning are respectively the electric motor main bodies 521L and 521R supported on the outer surface of the mission case 550, and the output in which the tip portion is inserted into the mission case 550. It has shafts 522L and 522R.

  A warm-up gear 523L (523R) is provided on the output shaft 522L (522R) of the turning electric motor 520L (520R) so as not to be relatively rotatable, and the ring gear of the corresponding differential mechanism 530L (530R) is provided. A gear that meshes with the warm-up gear 523L (523R) is provided on the outer peripheral surface of the 531L (531R).

A traveling drive shaft 31L (31R) of the corresponding traveling unit 30L (30R) is connected to the carrier 534L (534R).
In the present embodiment, the traveling unit 30L (30R) has a crawler traveling device.

Specifically, as shown in FIGS. 1 to 3, the traveling unit 30 </ b> L (30 </ b> R) is connected to the carrier 534 </ b> L (534 </ b> R) of the corresponding differential mechanism 530 </ b> L (530 </ b> R) along the body width direction. The travel drive shaft 31L (31R), the drive sprocket 32L (32R) supported so as not to rotate relative to the travel drive shaft 31L (31R), and the travel drive shaft 31L (31R) are separated in the longitudinal direction of the body. A traveling driven shaft 33L (33R) disposed along the width direction of the machine body at a predetermined position, a driven sprocket 34L (34R) supported so as not to rotate relative to the traveling driven shaft 33L (33R), and the drive sprocket 32L (32R) and a crawler 35L (35R) wound around the driven sprocket 34L (34R).
Of course, the traveling unit 30L (30R) may have a wheel-type traveling device instead of the crawler-type traveling device.

As shown in FIG. 2, the pair of left and right traveling portions 30L and 30R further includes a pair of left and right track frames 38L and 38R.
The corresponding traveling drive shaft 31L (31R) can rotate about its axis via a bearing (not shown) on one side of the track frame 38L (38R) in the longitudinal direction of the vehicle body (rear side in the present embodiment). And the corresponding travel driven shaft 33L (33R) is inserted through a bearing (not shown) on the other side in the longitudinal direction of the machine body (front side in the present embodiment). Has been.

In the present embodiment, the pair of left and right traveling portions 30L and 30R can move relative to the body frame 10 around the traveling drive shafts 31L and 31R by a hydraulic cylinder device 90 provided in the work vehicle 1. It is like that.
Specifically, as shown in FIG. 2, the pair of track frames 38L and 38R are connected to each other via a connecting frame 39 at a portion near the other side in the longitudinal direction of the machine body (the front side in the present embodiment). .
The hydraulic cylinder device 90 has one end connected directly or indirectly to the body frame 10 and the other end connected to the connecting frame 39.

  As shown in FIGS. 1 and 2, the operation unit 70 changes the output state of the HST 510 and the handle frame 71 erected on the body frame 10 so as to extend rearward and upward from the body frame 10. In order to change the output states of the shift operation member 72 that can be manually operated directly or indirectly on the handle frame 71 and the pair of left and right electric motors 520L and 520R for turning independently, A pair of left and right turning operation members 73L and 73R that are directly or indirectly provided on the frame 71 and that can be manually operated are provided.

The speed change operation member 72 is preferably a neutral position where the HST 510 is set in a neutral state to stop the traveling of the work vehicle 1, a forward-side highest speed position where the vehicle speed of the work vehicle 1 is maximized on the forward side, A predetermined forward maximum working speed position that is slower than the forward maximum speed position, a reverse maximum speed position at which the vehicle speed of the working vehicle 1 is maximum on the reverse side, and a predetermined reverse maximum operating speed that is slower than the reverse maximum speed position. Each position can be locked.
The preferred embodiment can be easily realized, for example, by forming a shift gate (not shown) for guiding the speed change operation member 72 in a step shape having step portions at the respective operation positions.

In the present embodiment, as shown in FIGS. 1 and 2, the speed change operation member 72 is provided in an operation box 700 supported by the handle frame 71.
The operation box 700 is further provided with a work clutch operation member 74 for manually operating the work clutch mechanism 105.

The pair of left and right turning operation members 73L and 73R are provided on the handle frame 71 in a state of being separated from each other in the body width direction.
Specifically, the handle frame 71 has a pair of left and right support frames 710L and 710R having a lower end supported by the body frame 10 and an upper end serving as a grip.

  The pair of left and right turning operation members 73L and 73R are connected to the gripping portions of the support frames 710L and 710R corresponding to the base ends so as to be swingable around the support shaft along the body width direction, respectively. The free end portion comes into contact with and separates from the grip portion in accordance with an artificial operation.

Preferably, a return spring (not shown) is provided that urges the free end of the turning operation member 73L (73R) in a direction away from the gripping portion of the corresponding support frame 710L (710R).
In such a configuration, the turning operation is performed by bringing the turning operation member 73L (73R) close to the gripping portion of the corresponding support frame 710L (710R) against the biasing force of the return spring by an artificial operation force. The member 73L (73R) is positioned at the operating position, and the turning operation member 73L (73R) is positioned at the non-operating position by releasing the manual operation force.
In addition, the code | symbol 26a in FIG. 1 is the battery stand constructed by the said support frames 710L and 710R.

Next, the control structure of the working vehicle 1 according to the present embodiment will be described.
FIG. 4 shows a system block diagram of a control device 400 provided in the work vehicle 1.

  As shown in FIG. 4, the working vehicle 1 further includes a speed change operation side sensor 410 that detects an operation state of the speed change operation member 72, a speed change electric actuator 80 that operates the output adjustment member 515 of the HST 510, and A shift operation side sensor 425 that directly or indirectly detects an operation state of the electric actuator for shifting, a generator 25 that generates electric power by rotational power from the engine 20, and a battery 26 that is charged by the generator 25 A starter 28 that starts the engine 20 using the electric power from the battery 26, a main operation member 78 that can be manually operated, a main power source / starter sensor 480 that detects an operation state of the main operation member 78, A control device 400 for controlling the operation of the electric actuator 80 for shifting and the starter 28; Eteori, the transmission electric actuator 80, the starter 28, the 410,425 sensor and the control unit 400 operates the battery 26 as a power source.

The speed-changing electric actuator 80 can take various forms as long as the operation is controlled by a control signal from the control device 400.
For example, the speed-changing electric actuator 80 can be an electric motor or a combination of a solenoid valve and a hydraulic actuator.

  The control device 400 performs on / off switching control of the main power source and on / off switching control of the starter 28 based on a signal from the main power source / starter sensor 480, and the shift operation side sensor 410 and the shift operation. The vehicle speed control is performed to control the operation of the electric actuator 80 for shifting based on a signal from the side sensor 425.

That is, the main operation member 78 is configured to be able to take a main power-off position, a main power-on position, and a starter operating position in order according to human operation.
The control device 400 shifts the work vehicle 1 from the main power-off state to the main power-on state in response to the operation of the main operation member 78 from the main power-off position to the main power-on position, and When the main operation member 78 is operated from the main power-on position to the starter operating position, the starter 28 is driven to start the engine 20.

The vehicle speed control 400 is executed in response to the operation of the main operation member 78 to the main power-on position.
That is, the control device 400 starts the vehicle speed control when the main operation member 78 is operated from the main power supply off position to the main power supply on position.

  In the vehicle speed control, the shift electric actuator 80 is controlled so that the shift operation position based on the detection signal of the shift operation side sensor 420 coincides with the shift operation position based on the detection signal of the shift operation side sensor 410.

  Specifically, the control device 400 includes a calculation unit 401 (hereinafter referred to as a CPU) including control calculation means for executing calculation processing based on signals input from the various sensors, a vehicle speed control program, control data, and the like. ROM that stores data, setting values, etc. are stored in a state that is not lost even when the power is turned off, and the setting values etc. can be rewritten and data generated during calculation by the calculation unit is temporarily held And a storage unit 402 including a RAM and the like.

The control device 400 has vehicle speed control data related to a shift operation position with respect to a shift operation position as the control data stored in the storage unit 402.
The vehicle speed control data is, for example, a control conversion formula or LUT (Look Up Table).

The shift operation side sensor 410 is, for example, a potentiometer that detects an operation position of the shift operation member 72 or a sensor that cumulatively detects an operation direction and an operation amount of the shift operation member 72.
The speed change operation side sensor 420 is connected to, for example, a potentiometer 426 that detects an operation position of the electric actuator 80 for speed change, or an operation position of the output adjustment member 515 (the control shaft 515a or the control shaft 515a. The potentiometer 427 detects the position of the control arm 515b.

Preferably, the work vehicle 1 further includes a shift output side in the form of a rotation sensor that detects a rotation direction and a rotation speed of any rotation member of a transmission path from the motor shaft 513 to the second transmission shaft 125. A sensor 420 may be provided.
In such a case, the vehicle speed control in a state where the engine 20 is driven is performed by detecting the detection signal from the shift operation side sensor 410 and the shift operation side sensor 425 and / or the shift output side sensor 420. Based on the detection signal.

  As shown in FIG. 4, the working vehicle 1 according to the present embodiment further includes a pair of left and right turning operation side sensors 430L and 430R that detect operation states of the pair of turning operation members 73L and 73R, A pair of left and right turning output side sensors 440L and 440R that detect output states of the pair of left and right turning electric motors 520L and 520R; a work clutch operation side sensor 460 that detects an operation state of the work clutch operation member 74; A work clutch electric actuator 600 for switching the transmission state of the work clutch mechanism 105 and a work clutch operation side sensor 470 for detecting the transmission state of the work clutch mechanism 105 directly or indirectly are provided.

  Therefore, in addition to the vehicle speed control, the control device 400 outputs the left and right turning electric motor actual output based on the detection signals of the left and right turning output side sensors 440L and 440R to the left and right turning operation side sensors 430L and 430R. The left and right turning electric motors 520L and 520R to be controlled so as to coincide with the left and right turning electric motor target output based on the detection signal, and the operation state of the work clutch operation member 74 according to the operation state of the work clutch operation member 74. Work control is performed to control the operation of the electric actuator 600 for the work clutch so that the transmission state of the work clutch mechanism 105 is switched.

The pair of left and right turning operation side sensors 430L and 430R, for example, cumulatively calculate the operation amount of the potentiometer sensor that detects the operation position of the pair of left and right turning operation members 73L and 73R or the turning operation members 73L and 73R. It is a sensor to detect.
The pair of left and right turning output side sensors 440L and 440R are, for example, rotation sensors that detect the rotation speed of the output shafts 522L and 522R.

The work clutch operation side sensor 460 is, for example, a potentiometer that detects the operation position of the work clutch operation member 74 or a contact switch that detects an ON / OFF signal according to the operation position of the work clutch operation member 74. .
The work clutch operating side sensor 470 is, for example, a potentiometer 471 that detects the operating position of the work clutch electric actuator 600 or the presence / absence of rotation of a transmission member from the driven side of the work clutch mechanism 105 to the work implement 40 This is a sensor 472 that detects.

As described above, the control device 400 starts the vehicle speed control in response to the operation of the main operation member 78 from the main power off position to the main power on position.
This is to ensure that the operating state of the shifting electric actuator 80 is adjusted to the operating position of the shifting operation member 72 when the engine 20 starts to be driven.

That is, for example, it is assumed that the engine 20 is stopped while the shift operation member 72 is positioned at a position other than the neutral position for some reason while the work vehicle 1 is being driven.
In this state, the shifting electric actuator 80 is stopped at the operating position other than the neutral position.
Therefore, if the control device 400 does not start the vehicle speed control when the main operation member 78 is positioned from the main power supply off position to the main power supply on position, the main operation member 78 starts the starter operation from the main power supply on position. The engine 20 starts to be driven while the HST is in a state other than the neutral state at the time when the working vehicle 1 is positioned, and the working vehicle 1 is suddenly started.

  In order to prevent such an inconvenience, the control device 400 is configured to start the vehicle speed control when the main operation member 78 is positioned from the main power off position to the main power on position.

  However, if the vehicle speed control is executed even when the starter 28 is driven, the control device 400 may cause the shift electric actuator 80 to malfunction.

  That is, the control device 400 is configured to execute the vehicle speed control based on a reference voltage using the power supplied from the battery 26, but the battery 26 is also used as a power source for the starter 28. It's being used.

Specifically, while the starter 28 is being driven, the voltage of the battery 26 may drop, and the reference voltage of the control device 400 may drop.
When the control device 400 executes the vehicle speed control with the lowered reference voltage, the normal operation control of the shift electric actuator according to the operation position of the shift operation member 72 cannot be performed. In spite of being positioned at the neutral position, the control device 400 may cause inconvenience such as operating the speed-changing electric actuator 80 forward.

  In order to prevent the inconvenience, in the working vehicle 1 according to the present embodiment, the control device 400 determines the vehicle speed according to the operation of the main operation member 78 from the main power off position to the main power on position. While starting the control, the operation control of the electric actuator 80 for shifting is prohibited while the starter 28 is in a driving state.

  According to such a configuration, by operating the main operation member 78 from the main power-off position to the main power-on position with the speed change operation member 72 positioned at the neutral position, the speed change electric actuator 80 is automatically set. Neutral. Therefore, when the engine 20 is started by operating the main operating member 78 from the main power-on position to the starter operating position, it is possible to effectively prevent the shifting electric actuator 80 from entering a state other than the neutral state.

Further, when the starter 28 is driven, the control device 400 does not control the operation of the electric actuator 80 for shifting. Accordingly, it is possible to effectively prevent malfunction of the speed-changing electric actuator 80 caused by a voltage drop of the battery 26 when the starter 28 is driven.
Furthermore, since the starter 28 and the shift electric actuator 80 are not operated simultaneously, the voltage drop of the battery 26 can be prevented as much as possible.

  Preferably, when the shift operation position and the shift operation position do not match (that is, when a deviation exceeding a predetermined dead band range occurs between the two), the control device 400 performs the shift operation. Pulse width modulation control is performed to output a control signal having a direction in which the position coincides with the speed change operation position and a pulse width corresponding to the magnitude of the deviation to the speed change electric actuator 80.

In such a preferred embodiment, when the starter 28 is driven, the control signal to the shift electric actuator 80 of the control device 400 is set to zero pulse width.
In the storage unit 402 of the control device 400, control data (such as an arithmetic expression or a look-up table) relating to the relationship between the magnitude of the deviation and the pulse width is stored in advance.

  As shown in FIGS. 1 to 2 and 4, the working vehicle 1 according to the present embodiment further includes a traveling clutch operating member 75 for engaging and disengaging the power transmission of the traveling system transmission path, and the traveling clutch operation. A travel clutch sensor 450 that detects an operation state of the member 75 is provided.

The travel clutch operation member 75 is a deadman clutch lever provided in the operation unit 70.
Specifically, as shown in FIGS. 1 and 2, the handle frame 71 is provided with a connecting frame 711 along the body width direction that connects the free ends of the pair of left and right support frames 710 </ b> L and 710 </ b> R.

  The travel clutch operating member 75 in the form of the deadman clutch lever is a clutch separated from the connection frame 711 while being urged by a biasing member (not shown) in a direction away from the connection frame 711. The handle frame 71 is supported by the handle frame 71 so as to be swingable about a rotation axis along the vehicle width direction so that a release position and a clutch engagement position close to the connection frame can be taken.

  That is, the traveling clutch operating member 75 in the form of the deadman clutch lever is positioned at the clutch engagement position by being gripped with the connecting frame 711 against the biasing force of the biasing member, and is gripped. By being released from the state, it is located at the clutch release position by the urging force of the urging member.

  When the control device 400 determines that the travel clutch operating member 75 is located at the clutch release position based on the signal from the travel clutch sensor 450, the control device 400 sets the HST 510 to the neutral state regardless of the operation state of the speed change operation member 72. The operation control of the electric actuator for shifting 80 is executed with the operating position of the electric actuator for shifting 80 to be the target position.

Here, the vehicle speed control program stored in the control device 400 will be described.
FIG. 5 shows a flowchart of the vehicle speed control program.

  According to the vehicle speed control program, the main operation member 78 is operated from the main power-off position to the main power-on position (step 10), and the work vehicle 1 is turned on (step 11). Start.

In step 12 and step 13, the control device 400 inputs a shift operation position and a shift operation position from the shift operation side sensor 410 and the shift operation side sensor 425, respectively.
As described above, the working vehicle according to the present embodiment includes the travel clutch operation member. In step 14 subsequent to step 13, the travel system transmission path is based on a signal from the travel clutch sensor 450. It is determined whether or not the power should be cut off.

First, the case where the determination in step 14 is NO (that is, the case where the travel clutch operating member 75 is located at the clutch engagement position) will be described.
In this case, vehicle speed control is executed using the shift operation position based on the detection signal from the shift operation side sensor 410 and the shift operation position based on the detection signal from the shift operation side sensor 425.

Specifically, if NO at step 14, the process proceeds to step 31.
In step 31, it is determined whether or not the deviation between the shift operation position and the shift operation position based on the signals input in step 12 and step 13 exceeds a predetermined dead zone range.

If YES in step 31 (that is, if the shift operation position does not match the shift operation position), in step 32, the control device 400 moves the shift operation position in the direction to match the shift operation position. A control signal having a pulse width corresponding to the magnitude of the deviation is output to the shift electric actuator 80.
Thereafter, it is determined again in step 31 whether or not the deviation exceeds a predetermined dead zone width. If NO (that is, if the shift operation position matches the shift operation position), the process proceeds to step 40. To do.

In step 40, it is determined whether or not to continue the vehicle speed control program.
Specifically, it is determined based on a signal from the main power / starter sensor whether or not the main operation member is located at the main power off position. If YES, the vehicle speed control program is terminated and NO In that case, the process returns to step 12.

  Next, the case where the answer is YES in Step 14 (that is, the case where the travel clutch operating member 75 is located at the clutch release position) will be described.

  If YES in step 14, the process proceeds to step 15 for determining whether or not the main operation member 78 is located at the starter operating position based on the signal from the main power source / starter sensor.

  If YES in step 15 (that is, if the main operation member 78 is located at the starter operating position), the process proceeds to step 16, and if NO (ie, the main operation member 78 is located in the starter operating position). If not, the process proceeds to step 21.

  In step 16, it is determined whether or not the speed change operation member 72 is positioned at the neutral position based on the signal from the speed change operation side sensor 410 in step 12. If YES, the starter 28 is driven. The process proceeds to step 17, and if NO, the process proceeds to step 21.

  That is, in the present embodiment, the main operation member 78 is positioned at the starter operating position while the travel clutch operation member 75 is positioned at the clutch release position and the speed change operation member 72 is positioned at the neutral position. This is a condition for driving the starter 28.

If NO in either step 15 or step 16, the process proceeds to step 21 as described above.
In step 21 and subsequent step 22, vehicle speed control is executed with the HST neutral position as the target position.

That is, the transition to the step 21 is based on the condition that the traveling clutch operating member 75 is positioned at the clutch release position in the step 14 as described above.
Therefore, in step 21, it is determined whether or not the shift operation position input in step 13 coincides with the HST neutral position (that is, whether or not the deviation between the shift operation position and the HST neutral position exceeds a predetermined dead band range). Is determined.

In the case of YES at step 21 (that is, when the shift operation position does not coincide with the HST neutral position), the control device 400 controls the direction in which the shift operation position coincides with the HST neutral position at step 22. A control signal having a pulse width corresponding to the magnitude of the deviation is output to the shift electric actuator 80.
Thereafter, it is determined again in step 21 whether or not the deviation exceeds a predetermined dead band width. If NO (that is, if the shift operation position matches the HST neutral position), the process proceeds to step 40. To do.

As described above, only when both step 15 and step 16 are YES, the routine proceeds to step 17 where the starter 28 is driven and the engine 20 is started.
In the state where the starter 28 is being driven, the control device 400 outputs a control signal having a pulse width of zero to the speed change electric actuator 80 (step 18), and proceeds to step 40.

That is, in a state where there is a high possibility that the voltage of the battery 26 is lowered because the starter 28 is driven, the control device is independent of whether or not the shift operation position matches the HST neutral position. Reference numeral 400 is configured not to operate the shift electric actuator 80.
Therefore, the malfunctioning of the electric actuator 80 for shifting due to the voltage drop of the battery 26 can be effectively prevented, and further the voltage drop of the battery 26 can be prevented as much as possible.

DESCRIPTION OF SYMBOLS 1 Work vehicle 20 Engine 25 Generator 26 Battery 28 Starter 30L, 30R Left and right traveling device 72 Shift operation member 78 Main operation member 80 Shifting electric actuator 400 Control device 410 Shift operation side sensor 425 Shift operation side sensor 480 Main power source / starter Sensor 510 HST
515 Output adjustment member

Claims (3)

An engine, a traveling unit, an HST interposed in a traveling system transmission path from the engine to the traveling unit, a shift operation member that can be manually operated, and an electric actuator for shifting that operates the output adjustment member of the HST A shift operation side sensor that detects an operation state of the shift operation member, a shift operation side sensor that directly or indirectly detects an operation state of the shift electric actuator, and power generation that generates electric power using rotational power from the engine An engine, a battery charged by the generator, a starter for starting the engine using the electric power from the battery, and a human power supply capable of taking a main power off position, a main power on position, and a starter operating position. A main operation member, a main power source / starter sensor for detecting an operation state of the main operation member, and the main power source / starter sensor; On / off switching control of the main power source and on / off switching control of the starter are performed based on the signal from the control signal, and the operation control of the electric actuator for shifting is performed based on the signals from the shift operation side sensor and the shift operation side sensor. A working vehicle including a control device for performing vehicle speed control for performing
The control device starts the vehicle speed control in response to an operation of the main operation member from a main power supply off position to a main power supply on position, and controls the operation of the shift electric actuator while the starter is on. A working vehicle that is configured to prohibit   In the vehicle speed control, the control device has a deviation exceeding a predetermined dead band range between a shift operation state based on a signal from the shift operation side sensor and a shift operation state based on a signal from the shift operation side sensor. If it occurs, a control signal having a pulse width corresponding to the magnitude of the deviation is output to the electric motor for shifting, and a control signal having a pulse width of zero is output to the electric actuator for shifting while the starter is on. The working vehicle according to claim 1, wherein   The control device does not drive the starter when the main operation member is operated from a main power-on position to a starter operation position in a state where the speed change operation member is located at a position other than a neutral position. The working vehicle according to claim 1 or 2.

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