JP5751928B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle including a detection sensor that detects a steering position.

  A detection sensor for detecting the steering position is connected to the pitman arm supported on the lower side of the transmission case, and the detection sensor detects the operating position of the pitman arm that operates in conjunction with the steering operation of the steering wheel. Thus, the work vehicle shown in Patent Document 1 that detects the steering position of the traveling machine body is known.

JP 2010-837 A

  However, in the above document, the detection sensor is arranged at a position away from the pitman arm on the lower side of the mission case, and the detection sensor and the pitman arm are connected by a linkage mechanism. It takes time and effort. In addition, if a detection sensor is provided directly on the pitman arm, the detection sensor will be disposed on the lower surface side of the transmission case facing the field scene close to the pitman arm. There is a risk of malfunction due to adhesion of muddy water.

  The present invention provides a work vehicle in which a detection sensor for detecting a steering position can be easily installed on the traveling machine body side with a simple configuration, and the installed detection sensor can be prevented from malfunctioning due to adhesion of muddy water or the like scattered from a farm field. The issue is to provide.

In order to solve the above problems, the present invention firstly is a work vehicle including a detection sensor 48 for detecting a steering position, and a deceleration mechanism 47 that decelerates the rotation of the steering shaft 33 and transmits it to the detection sensor 48. The speed reduction mechanism 47 is connected to a swinging arm of a potentiometer serving as the detection sensor 48 at a position away from the rotation shaft of the output gear 56 that outputs the reduced speed rotation. The regulating member 58 that regulates the movable range of the swing arm of the detection sensor 48 is formed on the support member 52 that supports the speed reduction mechanism 47 by contacting the connecting member 57 that rotates together with the output gear 56, thereby detecting The steering position is detected based on the rotational position of the steering shaft 33 detected by the sensor 48.

  Second, the speed reduction mechanism 47 and the detection sensor 48 are supported and provided inside a rectangular support frame 46.

  Third, the support frame 46 is provided in such a posture that both front and rear sides are opened, and the lever operating tools 27, 28, and 29 are supported on the left and right side portions of the support frame 46.

  By providing the deceleration mechanism on the steering shaft, the detection sensor can be disposed in the vicinity of the steering shaft, so that muddy water or the like scattered from the field is suppressed from adhering to the detection sensor, and failure of the detection sensor or the like can be prevented. At the same time, the configuration can be simplified.

  Further, if the speed reduction mechanism and the detection sensor are supported inside the rectangular support frame, maintenance of the speed reduction mechanism and the detection sensor can be easily performed from the open side of the support frame, and the speed reduction mechanism and the detection sensor can be easily maintained. The sensor can be stored in a compact size.

  Further, if the support frame is provided in a posture in which both front and rear sides are opened, and a lever operating tool is supported on the side of the support frame, the support frame supports a speed reduction mechanism and a detection sensor, and a steering shaft Since it also serves as a member that supports the lever operating tool on the side, the number of parts can be reduced and the cost can be reduced. improves.

  In addition, the speed reduction mechanism is supported on a support plate installed between both side portions of the support frame, and a restriction portion that restricts the operating range of the speed reduction mechanism is integrally formed on the support plate within the detection range of the detection sensor. For example, since the operating range of the speed reduction mechanism is within the detection range of the detection sensor even before the steering is assembled, the failure of the detection sensor is prevented, and the member that forms the restricting portion and the reinforcing member of the support frame Therefore, the number of parts is reduced and the cost is reduced.

It is the whole riding rice transplanter to which the work vehicle of the present invention is applied. It is a principal part side view which shows a steering mechanism. It is a side view which shows the internal side of the steering detection mechanism of FIG. It is a principal part front view which shows a steering detection mechanism. It is a principal part rear view which shows a steering detection mechanism. (A) is a perspective view which shows a reduction mechanism, (B) is a top view which shows the control part of a reduction mechanism. It is a block diagram of a control part. It is the schematic which shows the aspect of planting work machine automatic control.

Hereinafter, embodiments of the present invention will be described based on illustrated examples.
FIG. 1 is an overall side view of a riding rice transplanter to which a work vehicle of the present invention is applied. This riding rice transplanter includes a traveling machine body 3 supported by a pair of left and right front wheels 1 and a rear wheel 2, a planting work machine 6 connected to a rear side of the traveling machine body 3 via an elevating link 4, and a planting work machine 6. Spare seedlings 7 that are arranged between the attaching work machine 6 and the rear wheel 2 and that store the spare seedlings that are placed on the side of the traveling machine body 3 and placed on the planting work machine 6. It is comprised from the stand 8.

  The body frame 16 that supports the traveling body 3 is mounted with an engine (not shown) surrounded by a bonnet 17 on the front side, and an operator gets on the rear side of the engine to perform a steering operation or the like. A control unit 18 for performing the above is provided. A center pole 19 is provided upright at the center front of the bonnet 17.

  The steering unit 18 is disposed on the front side of the steering handle 23, a seat 21 on which an operator is seated, a steering handle 23 that is a steering operation tool for steering the front wheel 1 via the steering mechanism 22. An operation panel 24, a floor step 26 below the steering handle 23, a main transmission lever 27 for operating a shift by the main transmission mechanism, a sub transmission lever 28 for switching the sub transmission mechanism, and an engine speed. A throttle lever 29 (see FIGS. 2 to 5) for adjusting the brake and a brake pedal 31 for operating the brake operation of the traveling machine body 3 are arranged. The steering mechanism 22 will be described later.

  The planting machine 6 includes a seedling stage 9 on which the seedlings stocked on the reserve seedling stage 8 and the like are placed, and a planting operation for planting seedlings placed on the seedling stage 9 to the field. And a leveling work machine 7 that drives the leveling work machine 7. The leveling work machine 7 includes a prismatic leveling rotor 13 and a leveling work machine 7. And a leveling drive shaft 14 to which power is transmitted. Therefore, in this riding rice transplanter, the field roughened by the turning of the machine during the planting work is leveled by the leveling work machine 7 and seedlings are planted in the field after leveling using the planting work machine 6. It is configured.

Next, the steering mechanism will be described with reference to FIG.
FIG. 2 is a side view of the main part showing the steering mechanism. From the figure, the steering mechanism 22 includes a steering shaft 33 that is steeply inclined downward toward the front so that the steering handle 23 is attached to the upper end and is rotated around its own axis integrally with the steering handle 23. A pitman arm 37 that includes a transmission mechanism that shifts engine power to each part and is supported on the lower surface side of the transmission case 39 that is disposed between the left and right front wheels 1 and 1, and is swingably supported by the left and right sides. The left and right rods 38 are transmitted to the left and right front wheels 1 and 1 to adjust the steering angle (steering operation), and are disposed on the lower extension line of the steering shaft 33 and on the upper surface side of the transmission case 39. At the same time, the torque of the steering shaft 33 that is rotated by the steering operation force of the steering handle 23 is amplified to pitman. A hydraulic or electric (hydraulic in the illustrated example) power steering device 36 that causes the pitman arm to swing left and right by being transmitted to the wheel 37, and a cylindrical steering column 34 through which the steering shaft 33 is inserted. And.

  Most of the steering mechanism 22 excluding the pitman arm 37 side is surrounded on all sides, and the rear side is covered with a rear cover 32 installed in the control unit 18 so as to be freely opened and closed. Incidentally, although the steering shaft 23 rotates 360 degrees or more according to the operation range of the steering handle, the rotation range may be set to less than 360 degrees.

  The power steering device 36 is provided to be connected to the lower end side of the steering shaft 33, and maintains the same rotational speed for the rotational force input from an input shaft (not shown) disposed on the lower end side of the steering shaft 33. In this state, the torque is increased and output to an output shaft (not shown) that swings the pitman arm 37 left and right. Incidentally, when the power steering device 36 is a hydraulic type, the torque is amplified by hydraulic oil pumped by the engine power, whereas when the power steering device 36 is an electric type, the torque is amplified by an electric motor or the like. The output shaft rotates the pitman arm 37 below the mission case 39 via a sector gear (not shown) in the mission case 39 and the left and right front wheels 1 via a rod 38 connected to the pitman arm 37. , 1 is steered. Thereby, the operator can steer the steering handle 23 with a small operation torque.

  A steering detection mechanism 40 that detects the steering position of the traveling machine body 3 is provided around the middle portion of the steering column 34, and the left side of the steering detection mechanism 40 has the main transmission lever 27. An HST operation mechanism 42 for operating a hydrostatic continuously variable transmission 41 (HST) disposed on the side of the power steering device 36 in conjunction with the forward / backward swing operation is supported. This will be described below.

Next, the steering detection mechanism disposed in the steering column will be described with reference to FIGS.
3 is a side view showing the internal side of the steering detection mechanism of FIG. 2, and FIGS. 4 and 5 are a front view and a main part rear view showing the steering detection mechanism. ) Is a perspective view showing the speed reduction mechanism, and FIG. 5B is a plan view showing a restricting portion of the speed reduction mechanism. The steering detection mechanism 40 supports a steering column 34, a rectangular support bracket 46 (support frame) through which the steering shaft 33 is inserted, and a speed reduction unit that transmits the rotation of the steering shaft 33 by reducing gear speed. 47, and a potentiometer (detection sensor) 48, which is a steering sensor that detects a steering operation by detecting a rotation amount (rotation amount) decelerated by the deceleration unit 47.

  The support bracket 46 is formed in a frame shape that is open in the front-rear direction. The lower end surface of the support bracket 46 is inserted into the steering shaft 33 and supported by the upper end surface of the power steering device 36. Further, the middle portion of the HST operation mechanism 42 is supported on the left side surface of the support bracket 46, and the interlocking mechanism 50 that interlocks the operations of the auxiliary transmission lever 28 and the throttle lever 29 is supported on the right side surface.

  Specifically, the HST operation mechanism 42 includes a rod-like extension portion 27a extending from the main transmission lever 27 to the left side surface of the support bracket 46, and a shaft provided outward from the left side surface of the support bracket 46. A pivot support 44 that serves as a pivot when the main transmission lever is pivoted back and forth, and a connecting rod 45 that is pivotably attached to the pivot support and is connected to the HST side. It consists of and. Further, as the interlocking mechanism 50, a support shaft 55 protrudes from the right side surface of the support bracket 46 so as to be rotatable outward (right), and the extended portion 28a of the auxiliary transmission lever 28 is supported. ing. The throttle lever 29 is rotatably mounted on the right side surface of the support bracket 46, and the swing angle of the throttle lever 29 is detected by a detection sensor 60 provided in the support bracket 46 (FIG. 5). reference).

  Furthermore, the upper end surface that bridges the upper end side of the left and right side surfaces of the support bracket 46 connects the left and right side surfaces, and has an arc-shaped recess, and the steering column 34 is fitted into the recess, so that the support bracket 46 is attached to the steering column 34 side more stably. The support bracket 46 is attached to the steering column 34 so as to be shifted to the right side (see FIGS. 4 and 5).

  A reinforcing plate 51 extending in the left-right direction is installed in the middle of the support bracket 46. The potentiometer 48 is installed on the upper surface side of the reinforcing plate 51, and the lower surface side of the reinforcing plate 51 is The deceleration unit 47 is installed. Hereinafter, a configuration in which the steering position of the traveling machine body 3 is detected by detecting the rotation of the steering shaft 33 using the deceleration unit 47 and the potentiometer 48 will be described.

  The speed reducing portion 47 is below the reinforcing plate 51 inside the support bracket 46, and similarly to the reinforcing plate 51, a support plate 52 erected in the left-right direction, and an input gear 53 provided on the steering shaft 33. A reduction gear 54 attached to the support plate 52 and integrally formed with a large-diameter gear portion 54a and a small-diameter gear portion 54b having a diameter larger than that of the input gear 53; And an output gear 56 having a diameter larger than that of the small-diameter gear portion 54b. The steering column 34 extends from the upper side of the steering shaft 33 to the upper surface side of the reinforcing plate 51, and the steering shaft 33 is exposed from the lower surface side of the reinforcing plate 51.

  In the above, the input gear 53 rotates integrally with the rotation of the steering shaft 33 accompanying the steering operation of the steering handle 23. The input gear 53 is configured to mesh with the large-diameter gear portion 54a of the reduction gear 54 disposed on the lower surface side of the support plate 52. Accordingly, the input gear 53 is disposed on the upper surface side of the support plate 52. The small-diameter gear portion 54b rotates integrally. The small diameter gear portion 54 b meshes with the output gear 56 disposed on the center of the upper surface of the support plate 52.

  That is, when the rotation of the steering shaft 33 is transmitted from the input gear 53 to the large-diameter gear portion 54 a of the reduction gear 54 and from the small-diameter gear portion 54 b of the reduction gear 54 to the output gear 56, the rotation of the steering shaft 33 starts from the small-diameter gear. Since the transmission is transmitted to a gear having a large diameter, the rotation of the steering shaft 33 is decelerated in two stages and the output gear 56 is rotated.

  The output gear 56 is supported so that approximately one third of the gear plane protrudes rearward from the front-rear width of the support plate 52, and penetrates the gear plane of the output gear 56 in the vertical direction. A fixed output pin 57 is provided to rotate integrally with the output gear 56 on the rear side of the support plate 52.

  The upper end side of the output pin 57 protruding above the output gear 56 is connected to the ponometer 48 installed on the reinforcing plate 51, and the potentiometer 48 detects the rotation amount (rotation amount) of the output pin. Thus, the rotation amount of the steering shaft 33 is detected, and thereby the steering operation position of the traveling machine body 3 is detected.

  At this time, the swing arm of the potentiometer 48 is disposed so as to bias the output pin 57 from one side, and detects the bias position of the swing arm that fluctuates in conjunction with the operation of the steering handle (FIG. 6). (See (A)), the swing arm of the potentiometer 48 may be directly attached to the output pin 57 and swing left and right in accordance with the left and right rotation of the steering.

  Further, the lower end side of the output pin 57 projecting downward from the output gear 56 projects to the rear side of the support plate 52, and a pair of restricting portions 58 formed to extend to the rear side of the support plate 52. , 58 is configured so that the output pin 57 rotates only within the range of the output pin 57, and the rotation of the output pin 57 outside the above range is the contact between the lower end side of the output pin 57 and the restricting portions 58, 58 (See FIG. 6B).

  The output pin 57 is decelerated with the above configuration, so that the lower end side of the output pin 57 does not come into contact with the restricting portions 58 and 58 even when the steering handle 23 is steered to the maximum. Therefore, when the output pin 57 attached to the output gear 56 rotates left and right, the output pin 57 is not damaged due to overload when the output pin 57 is in contact with the support plate 52. However, in particular, even when the steering shaft 33 is excessively rotated during the assembly operation of the steering detection mechanism 40 or during the maintenance thereof, the output pin 57 is rotated out of a predetermined range by the restriction portions 58 and 58. Therefore, it is possible to prevent a failure of the potentiometer 48 attached to the upper end side of the output pin 57.

  According to the steering detection mechanism 40 of the configuration, since the potentiometer 48 can be installed on the lower end side of the steering column 34, even when performing planting work or the like in the field, it is possible to use muddy water or the like in the field. Failure can be prevented. Further, the support bracket 46 that supports the steering detection mechanism 40 has a frame shape that is open in the front-rear direction, and the speed reduction portion 47 and the potentiometer 48 are housed in the frame of the support bracket 46, so that the structure is simple. In addition, the steering detection mechanism 40 can be easily maintained from the control unit 18 side by removing the rear cover 32 on the control unit 18 side.

  Incidentally, the support plate 52 has a configuration in which the right end side is bent downward and is bolted to the right side surface of the support bracket 46, and the left end side is bent into a bowl shape facing upward and is bolted to the lower end side of the reinforcing plate 51. Therefore, since the speed reducing portion 47 can be easily attached and detached from the inside of the support bracket 46, the maintenance is more excellent.

The steering position (rotation of the steering shaft) of the traveling machine body 3 detected by the potentiometer 48 of the steering detection mechanism 40 described above is used for the following control by the control unit 61 described later.
If the steering operation of the front wheel 1 is detected when the traveling machine body 3 performing the planting operation reaches the heel, the planting work machine 6 stops driving and is driven upward, so that the traveling machine body 3 is planted. When the planting machine 6 is swung to the position where the planting work is started, the planting work machine 6 is automatically driven to descend and used for planting machine automatic control for starting the planting work. Details will be described later.

  In detecting the steering position, the steering detection mechanism 40 detects the rotation speed of the steering shaft 33 located on the upstream side of the power steering device 36. It can also be used for power steering control via the steering device 36.

Next, the configuration of the control unit will be described based on FIG. 7 and FIG.
FIG. 7 is a block diagram of the control unit. On the input side of the control unit 61, a work machine preparation switch 62 for switching the control unit to a state where planting work is possible, and a work machine operation lever including the main transmission lever 27, the sub transmission lever 28, the throttle lever 29, and the like. 27, 28, 29, turning automatic switch 63 for switching ON / OFF of the above-described planting work machine automatic control, and an adjustment dial 64 for adjusting the on / off timing of the planting clutch 68 in the planting work machine automatic control. And a steering sensor 48 that is a potentiometer 48 of the steering detection mechanism 40 and a rear wheel rotation sensor 66 that measures the travel distance based on the number of rotations of the rear wheels 2 and 2. On the other hand, on the output side of the control unit 61, a hydraulic valve 67 that moves up and down the planting work machine 6 and a planting clutch 68 that turns on and off the drive of the planting work machine 6 are provided.

  FIG. 8 is a schematic view showing an aspect of planting work machine automatic control. As shown in the figure, when the planting clutch 68 is turned on in the state in which the turning automatic switch 63 is turned on and the seedling is planted in the field, the planting work is performed up to one end of the field. When the steering sensor 48 detects that the steering handle 23 has been steered more than a predetermined amount to make a turn (A), the planting clutch 68 is turned off via the controller 61. The planting machine 6 is driven up by the hydraulic valve 67. Next, when it is detected that the travel distance measured by the rear wheel rotation sensor 66 has reached a predetermined distance from the position where the steering handle 23 detects a steering operation more than a predetermined value (B), the hydraulic valve The planting work machine 6 is driven to descend by 67, and the steering handle 23 is steered more than a predetermined distance, and then travels a predetermined traveling distance for starting planting, and the lowering of the planting work machine 6 is completed. In the case (C), the planting clutch 68 is turned on to restart the planting operation.

  At this time, since the timing (distance (A)-(C) of FIG. 8) at which the planting clutch 68 is turned on and off is configured to be adjustable by the adjustment dial 64, the turning work in the field It is possible to adjust the on / off of the planting work at the appropriate time.

27 Main transmission lever (lever operation tool)
28 Sub-shift lever (lever operation tool)
29 Throttle lever (lever operation tool)
33 Steering shaft 46 Support bracket (support frame)
47 Reduction gear (deceleration mechanism)
48 Potentiometer (detection sensor)
52 Support plate 58 Regulator

Claims (3)

A work vehicle equipped with a detection sensor (48) for detecting a steering position, wherein a deceleration mechanism (47) for decelerating the rotation of the steering shaft (33) and transmitting it to the detection sensor (48) is provided to the steering shaft ( 33), and the speed reduction mechanism (47) swings the potentiometer serving as the detection sensor (48) at a position away from the rotational axis of the driven gear (56) that outputs the reduced speed rotation. The arm is connected, and the support member (52) supporting the speed reduction mechanism (47) is brought into contact with the connecting member (57) that rotates together with the driven gear (56), thereby swinging the detection sensor (48). A work vehicle that forms a restricting portion (58) that restricts the movable range of the moving arm and detects the steering position based on the rotational position of the steering shaft (33) detected by the detection sensor (48).   The work vehicle according to claim 1, wherein the speed reduction mechanism (47) and the detection sensor (48) are supported inside a rectangular support frame (46).   The work vehicle according to claim 2, wherein the support frame (46) is provided in a posture in which both front and rear sides are opened, and a lever operating tool (27, 28, 29) is supported on the left and right side portions of the support frame (46). .

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