JP4585406B2 - Side clutch switching mechanism of riding type rice transplanter - Google Patents

Description

  The present invention relates to a structure of a side clutch switching mechanism of a riding type rice transplanter that performs an on / off operation of a side clutch in conjunction with an operation of a steering means.

Conventionally, in a riding type rice transplanter, left and right side clutches are provided on a rear axle shaft disposed in a rear axle case, and during turning operation, the side clutch for the rear wheel inside the turning direction is cut off, By turning off the power transmission in conjunction with the turning operation of the steering handle by the side clutch switching mechanism, the turning performance of the airframe has been improved. The side clutch switching mechanism includes a link mechanism and a cam mechanism, and is interposed between the steering handle and the left and right side clutches. The clutch operating force from the steering handle is transferred to the side clutch via the link mechanism and the cam mechanism. It is configured to transmit and perform the on / off operation of the side clutch. That is, a cam member and left and right operation arms having rollers that can come into contact with the cam member are supported on a fulcrum shaft provided on the axle case so as to be horizontally rotatable, and the cam member and the steering handle are supported by a rod. By interlocking and connecting, when the steering handle is turned, the cam is rotated by pushing and pulling the rod in the front-rear direction, and the operation arm is rotated by contacting the roller on the left or right operation arm. The clutch operating member provided on the axle shaft is caused to act on the side clutch so that the side clutch is disengaged and the wheel on the inner side in the turning direction is not driven.
JP 2002-340021 A

  However, in the side clutch switching mechanism provided in the conventional riding type rice transplanter, when the rod is pushed and pulled in the front-rear direction in conjunction with the turning operation of the steering handle, the rod is pushed and pulled. However, since the cam member has a symmetrical shape and the rod is connected to one end of the cam, the cam member has left and right rotations with respect to a predetermined amount of rotation in the left or right direction of the steering handle. The timing of acting on the operating arm may shift. That is, when turning left and turning right, the time when the on / off operation of the side clutch inside the turning direction may be shifted by the amount of deflection of the rod. Therefore, the turning radius of the traveling machine body is slightly different on the left and right, and the turning performance is impaired.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In claim 1, the steering means and the left and right side clutches are linked and linked by a link mechanism and a cam mechanism, and the cam member is rotated in conjunction with the operation of the steering means. And left and right operation arms that act via the rollers, and a clutch operation member that acts on the left and right side clutches via the operation arm, and the steering mechanism and the cam member are connected to the link mechanism. are pushed or pulled in the side clutch switching mechanism of the riding rice transplanters having a rod that rotates the cam member by means, said cam member configured asymmetrical shape with respect to the rotation center, of the cam member rotating When the center of movement is shifted from the left and right center of the body to the left and right sides, the rod is disposed on the other side of the left and right, and the rod is pushed and bent in the direction of bending when the steering means is rotated. The cam member The distance between the center of rotation of the latch operating position and the cam member, when said rod is pulling rotated in a direction, than the distance between the center of rotation of the clutch operating position and the cam member of the cam member, and configured longer Is.

  As effects of the present invention, the following effects can be obtained.

In claim 1, the steering means and the left and right side clutches are linked and linked by a link mechanism and a cam mechanism, and the cam member is rotated in conjunction with the operation of the steering means. And left and right operation arms that act via the rollers, and a clutch operation member that acts on the left and right side clutches via the operation arm, and the steering mechanism and the cam member are connected to the link mechanism. are pushed or pulled in the side clutch switching mechanism of the riding rice transplanters having a rod that rotates the cam member by means, said cam member configured asymmetrical shape with respect to the rotation center, of the cam member rotating When the center of movement is shifted from the left and right center of the body to the left and right sides, the rod is disposed on the other side of the left and right, and the rod is pushed and bent in the direction of bending when the steering means is rotated. The cam member The distance between the center of rotation of the latch operating position and the cam member, when said rod is pulling rotated in a direction, than the distance between the center of rotation of the clutch operating position and the cam member of the cam member, and configured longer Therefore, when the rod is pushed and pulled in the front-rear direction in conjunction with the operation of the steering means, there is a difference in the amount of bending of the rod when the rod is pushed and pulled, but the side clutch is engaged regardless of the turning direction. It can be turned on and off at approximately the same time. Therefore, the turning performance can be improved by setting the left and right turning radii to be the same.

Moreover , a drive part etc. can be arrange | positioned in the vehicle body left-right center vicinity, and the freedom degree of arrangement | positioning layout of each part in a traveling body can be improved.

In addition , the amount of deflection when the rod is pushed is larger than the amount of elongation when the rod is pushed, but when the rod is pushed, the distance from the turning center of the cam member to the operating position is longer, so the same turning angle. Even when pressed, it can act longer, absorb the deflection of the rod, and eliminate the shift of the side clutch on / off operation timing due to the steering operation when turning left and right . Further, it is possible to prevent an error from occurring in the left and right turning radius.

  Next, embodiments of the invention will be described.

  FIG. 1 is a perspective view showing an overall configuration of a riding type rice transplanter including a side clutch switching mechanism according to an embodiment of the present invention, and FIG. 2 is a perspective view of a traveling machine body.

  3 is a side view of the front part of the traveling machine body, FIG. 4 is a view showing a side clutch switching mechanism, FIG. 5 is a lower perspective view of the rear part of the traveling machine body, FIG. 6 is a front perspective view of the cam mechanism, and FIG. FIG.

  8 is a plan view of the cam mechanism in the straight traveling state, FIG. 9 is a plan view of the cam member, FIG. 10 is a plan view of the cam mechanism in the left turn starting state, and FIG. 11 is a plan view of the cam mechanism in the right turn starting state. is there.

  As shown in FIGS. 1 and 2, the riding type rice transplanter 1 is provided with a traveling machine body 2 and a planting device 17 attached to the rear part of the traveling machine body 2 so as to be movable up and down. The traveling machine body 2 includes a main frame 3, 3 mainly composed of a pair of left and right frames extended mainly in the longitudinal direction of the machine body, and an integrated case body that is disposed between the left and right main frames 3, 3 and is long in the longitudinal direction of the machine body. And a connecting frame 5 which is connected to the mission case 4 between the left and right main frames 3 and extends rearward of the machine body, and has a U-shape facing downward in a front sectional view.

  Front axle cases 6 project from left and right side surfaces of the transmission case 4 in the longitudinal direction of the vehicle body, and front wheels 7 are attached to both left and right ends of the front axle case 6. A rear axle case 8 is attached to the rear end of the connecting frame 5, and rear wheels 9 are attached to the left and right ends of the rear axle case 8. A pair of left and right support frames 10 are erected on the rear axle case 8, and a planting device 17 is connected to the support frame 10 via a parallel link mechanism 11 including upper and lower links.

  The planting device 17 includes a pair of left and right transmission cases 13 to which power is transmitted by being connected via a universal joint shaft 41 and a PTO shaft 36 mainly projecting rearward from the rear end of the transmission case 4, and a traveling machine body. 2 is attached to both the left and right sides of each transmission case 13, the seedling stage 14 that is forwardly inclined so that the upper end approaches the rear part, the float 15 that is disposed on the lower surface of each transmission case 13, and the field scene and the seedling The planting mechanism includes planting claws that are planted separately from the seedling mat on the seedling platform 14 while planting up and down between the lower ends of the platform 14. And the raising / lowering hydraulic cylinder 16 provided in the rear part of the said connection flame | frame 5 is attached in relation to the parallel link mechanism 11, and the planting apparatus 17 can be raised / lowered with respect to the traveling body 2. FIG.

  Further, a vehicle body cover 18 is attached to the main frame 3 so as to cover the traveling machine body 2 from above, and a seat 19 is disposed above the rear portion of the vehicle body cover 18. A bonnet 20 is disposed in front of the seat 19 and is fixed to the upper surface of the front portion of the vehicle body cover 18. Spare seedling platforms 21 are arranged on the left and right sides of the bonnet 20, and as shown in FIG. 3, in the bonnet 20, the engine 22 and its accessories, such as a vaporizer, a governor, An air muffler, a starter coiler (rope starter), a silencer, and the like are arranged.

  A mission case 4 is disposed below the engine 22. As shown in FIG. 4, in the mission case 4, a steering steering mechanism 25 for steering is provided on the front side, and a power transmission mechanism 26 that can transmit power to the traveling drive system and the PTO drive system on the rear side. Is provided. A belt transmission mechanism comprising pulleys 28 and 29 with a slack adjusting mechanism 27 and a belt 30 between an input shaft 4a projecting outward from the left and right side surfaces of the transmission case 4 and an output shaft 22a of the engine 22 is provided. Is provided so that power can be transmitted from the output shaft 22a to the input shaft 4a, and power can be transmitted from the input shaft 4a to the power transmission mechanism 26 in the transmission case 4.

  The power transmission mechanism 26 includes a gear-type transmission mechanism 35 that changes the rotational speed transmitted from the input shaft 4a, and a PTO shaft 36 that protrudes rearward from the gear-type transmission mechanism 35 through the rear wall of the transmission case 4. PTO clutch for performing on / off operation of transmission of power to the PTO shaft 36, front axle shafts 39 and 39 projecting from the differential mechanism 38 to the left and right sides, and the gear type transmission mechanism 35 penetrating through the side wall of the transmission case 4. And an output shaft that protrudes to the opposite side of the input shaft 4a, a main clutch that performs an on / off operation of transmission of power to the output shaft, and the like.

  The PTO shaft 36 is interlocked and connected to the input shaft of the transmission case 13 provided in the planting device 17 via a universal joint shaft 41 extending in the longitudinal direction of the machine body, so that power can be transmitted to the input shaft. It is configured to be able to. The universal joint shaft 41 is disposed in the inner space so that the front part extends on the left and right center O1 of the fuselage and is covered with the connecting frame 5 that connects the transmission case 4 and the rear axle case 8. It is supported on the rear axle case 8.

  The output shaft of the transmission case 4 is interlocked with an input shaft 8a protruding forward from the front surface of the rear axle case 8 via a transmission shaft 42 extending in the front-rear direction of the fuselage, and transmits power to the input shaft 8a. It is configured to be able to. The transmission shaft 42 is provided substantially parallel to the front portion of the universal joint shaft 41 at a position shifted to the left and right sides with respect to the left and right center O <b> 1, and is disposed on the outer side of the connection frame 5.

In the rear axle case 8, as shown in FIG. 5, the input shaft 8 a is interlocked and connected to a rear axle shaft 44 extending left and right via a pair of bevel gears, and both left and right ends of the rear axle shaft 44 are connected. In addition, side clutch shafts 46 and 46 are connected via side clutches 45 and 45, respectively.
The left and right side clutch shafts 46 are linked to the axle 48 of the rear wheel 9 via the speed reduction mechanism 47 so that power can be transmitted to the axle 48 from the input shaft 8a. Thus, by performing the on / off operation of the side clutches 45 and 45 using a side clutch switching mechanism composed of a link mechanism 70A and a cam mechanism 70B, which will be described later, the left and right rear wheels 9 and 9 are driven synchronously, Only one of the left and right rear wheels 9 can be driven.

  On the other hand, the left and right front axle shafts 39 and 39 are arranged in front axle cases 6 and 6 provided so as to protrude from the left and right side surfaces of the middle part of the front and rear of the transmission case 4, and the front wheels 7 are connected via a speed reduction mechanism.・ It is linked to 7 axles 40 and 40. Thus, power can be transmitted from the input shaft 4a of the transmission case 4 to the axles 40 and 40, and the front wheels 7 and 7 can be driven.

  Further, a steering lower shaft 51 protrudes upward from the steering drive mechanism 25 built in the front part of the transmission case 4 through the upper wall of the transmission case 4 and is connected to the upper end of the steering lower shaft 51 via a universal joint. The lower end of the shaft 52 is connected to bendable. A steering upper shaft 52 extends to the upper part of the bonnet 20, and a steering handle 53 serving as a steering means is attached to an upper end of the steering upper shaft 52. The steering lower shaft 51 and the steering upper shaft 52 are disposed on the front side in the bonnet 20, and each has a cylindrical lower column 54 fixed on the front portion of the transmission case 4, and a cylindrical upper column supported by the lower column 54. It is covered with a column 55.

  A rotating shaft 57 passes through the transmission case 4 and protrudes downward from the steering drive mechanism 25, and a front arm 58 is provided on the rotating shaft 57 so as to protrude forward. The front arm 58 and the rear arm 59 are provided so as to protrude to the side, and can rotate integrally with the rotation of the rotation shaft 57. The front arm 58 constitutes a link mechanism 62 together with a connecting rod and a tie rod, and the steering direction of the front wheels 7 and 7 can be changed by turning the steering handle 53.

  The rear arm 59, together with the rod 65 and the rotating arm 66, constitutes a link mechanism 70A of the side clutch switching mechanism. That is, the front end of the rod 65 is pivotally connected to the tip of the rear arm 59, the rod 65 extends in the front-rear direction to the front of the rear axle case 8, and the rear end is supported by one end of the rotating arm 66. The rotating arm 66 is fixed to a lower end of a fulcrum shaft 67 whose other end penetrates the connecting frame 5 in the vertical direction, and a boss 68 fixed to the inner side of the connecting frame 5 so as to avoid the universal joint shaft 41. The shaft 67 is inserted so as to be rotatable. A cam member 71 forming a part of the cam mechanism 70B of the side clutch switching mechanism is fixed to the upper end of the fulcrum shaft 67 protruding upward from the connecting frame 5, and the cam member 71 and the rotating arm 66 are connected to the rear arm. The link mechanism 70 </ b> A is configured so as to horizontally rotate integrally by pushing and pulling the rod 65 in the front-rear direction along with the rotation of 59. A turnbuckle 65a is provided in the middle of the front and rear of the rod 65 so that the front and rear length of the rod 65 can be easily adjusted so that the on / off operation of the left and right side clutch 45 can be adjusted.

  The cam member 71 includes a pair of left and right clutch operating members 72 and 72 for turning on and off the left and right side clutches 45, left and right arm shafts 73 and 73 having cam portions 73a and 73a, rollers 74 The cam mechanism 70B is configured with the left and right operation arms 75 and 75 having 74, and the like. The left and right clutch operating members 72 and 72 are slidably provided on the rear axle shaft 44 in the rear axle case 8 and are disposed in the vicinity of the left and right side clutches 45 and 45, respectively. And the cam part 73a formed in the lower part of the arm shaft 73 is joined to the inner surface of each clutch operating member 72 on either side.

  The left and right arm shafts 73 protrude upward from the upper surface of the rear axle case 8, and one end of the operation arm 75 is fixed to the upper end of the left and right arm shafts 73 so that the operation arm 75 and the cam portion 73 a of the arm shaft 73 are integrated. Horizontal rotation is possible. The left and right operation arms 75 and 75 are arranged behind the cam member 71, and the other ends thereof are arranged at equal intervals on both the left and right sides of the left and right center O1, so that they substantially overlap the left and right ends of the cam member 71 in front view. Is provided. Rollers 74 and 74 having support shafts arranged in the vertical direction are rotatably supported on the other ends of the operation arms 75 and 75, and abut against a cam portion 71a formed on the outer peripheral rear side of the cam member 71. It is possible.

  The cam member 71 is formed of a plate-like member, and is configured to be asymmetrical by extending to the left and right sides with the fulcrum shaft 67 as a center. In this embodiment, the cam member 71 is supported by the fulcrum shaft 67 at a position shifted to the right side from the left and right center O1 of the machine body. In other words, the fulcrum shaft 67 is arranged on the right side of the left and right center O1 of the machine body. It arrange | positions on the left side on the opposite side rather than the left-right center O1. The left and right ends of the cam member 71 are extended in the left-right direction until they are positioned in the vicinity of the rollers 74, 74 on the operation arms 75, 75, respectively, and the left side is asymmetrical in shape with a longer width in the left-right direction than the right side It is said that. The left and right arms 75 and 75 have the same length.

  In other words, when the steering handle 53 is rotated, the rod 65 is pushed or pulled and the cam member 71 is rotated, and the left and right operation arms on the left and right sides of the cam member 71 via the rollers 74 and 74. The side clutches 45 and 45 are actuated by rotating the 75 and 75, but the rod 65 is bent when pushed, causing an operation delay. That is, if the distance from the fulcrum shaft 67 to the roller 74 contact position is the same, even if the steering handle 53 is rotated at the same left and right angles when turning, the angle for pulling the rod 65 is substantially set and the side clutch is Although it is “disengaged”, the side operated by pushing the rod 65 will not be able to be disengaged unless the angle is larger than the set angle, and the turning radius will increase. Therefore, the side on which the left operating arm 75 is acted by pushing the rod 65 is configured so that the left operating arm 75 can be rotated by the same angle even if the steering handle 53 is operated at the same angle. The distance to the contact position is longer on the left side (longer width) than on the right side. As a result, when the steering handle 53 is operated at the same angle, the stroke of the cam member 71 to the contact position of the left roller 74 is larger than that on the right side, so that there is no operation delay and the left and right can be turned approximately equally. It becomes. When the steering handle 53 is directed straight in the neutral position, the left side of the cam portion 71a does not come into contact with the roller 74 on the left operation arm 75, and resistance is maintained until the neutral position is activated. It is supported so as to be able to turn in the horizontal direction around the fulcrum shaft 67 as a turning center so that the right side comes into contact with the roller 74 on the right operation arm 75 so as to be as small as possible.

  In the cam member 71, the cam portion 71 a has an outer peripheral shape in which an arc portion 71 c having the same radius is formed from the rear portion to the right side of the fulcrum shaft 67, and the “off” operation start position of the side clutch 45 is formed. A bent portion 71d that is recessed forward is formed in the middle portion, and the shape extends to the right side to reach the right short portion. The left side from the rear portion of the fulcrum shaft 67 is such that the tangent line of the circular arc portion 71c extends obliquely to the left and forward so that it protrudes backward in the middle of the side clutch 45 where the "off" operation starts. A bent portion 71b bent in a letter shape is formed, and the angle is made larger than that of the bent portion 71b so as to extend diagonally to the left and reach the left end. As the steering handle 53 rotates, the left or right bent portions 71b and 71d come into contact with the rollers 74 and 74 on the left and right operation arms 75 and 75 along with the rotation of the cam member 71, and further in the same direction. When the side clutches 45 and 45 are turned, the outer side of the bent portions 71b and 71d at the starting position of the cutting operation in this way increases the inclination on the left side on the side farther from the fulcrum shaft 67, so The “off” operation is made substantially the same on the left and right.

  Thus, when the cam member 71 is in the neutral state, the cam portion 71a does not contact the roller 74 on the left operation arm 75 but contacts the roller 74 on the right operation arm 75 against the arc portion 71c. Both side clutches 45 and 45 are in a state of being engaged. Then, when the steering handle 53 is rotated counterclockwise and the rod 65 is pushed rearward, the cam member 71 horizontally rotates counterclockwise (counterclockwise in FIG. 8) about the fulcrum shaft 67 in plan view. When turning, the steering handle 53 is further rotated, the left bent portion 71b of the cam portion 71a comes into contact with the roller 74 on the left operation arm 75, and the cam member 71 is further rotated in the same direction. At this time, the rod 65 is pushed backward while being bent, but since the position of the bent portion 71b from the fulcrum shaft 67 is longer than the distance to the bent portion 71d, the moving distance becomes longer even at the same left and right turning angles. The bending length can be absorbed. As a result, the roller 74 is pushed by the cam member 71, and the left operation arm 75 is horizontally rotated clockwise in a plan view (clockwise in FIG. 8) about the arm shaft 73, and the left operation The cam portion 73a formed at the lower portion of the arm shaft 73 is brought into contact with the left clutch operation member 72 by the rotation of the arm 75, and the left clutch operation member 72 is pushed toward the left side clutch 45, so that the left side clutch 45 is disengaged. . At this time, the roller 74 on the right operation arm 75 is in contact with the cam portion 71a of the cam member 71 at the arc portion 71c. Since it moves toward the center of the left and right while rolling along 71c, the right operation arm 75 is not rotated and the right side clutch 45 remains engaged.

  On the other hand, when the steering handle 53 is rotated clockwise, the rod 65 is pulled, and the cam member 71 is horizontally rotated clockwise in plan view around the fulcrum shaft 67 from the neutral state. Then, the roller 74 on the right operation arm 75 that contacts the arc portion 71c of the cam portion 71a moves toward the right bent portion 71d while rolling along the arc portion 71c. Then, the cam member 71 is further rotated in the same direction in a state where the right bent portion 71d is in contact with the roller 74, so that the roller 74 rolls from the bent portion 71d to the side cam portion 71a. It abuts and moves to the vicinity of the right end along the cam portion 71a. At this time, the rod 65 is pulled, but there is almost no elongation. As a result, the roller 74 is pushed by the cam member 71, and the right operation arm 75 is horizontally rotated counterclockwise around the arm shaft 73 in plan view. A cam portion 73a formed at the lower portion of the shaft 73 contacts the right clutch operating member 72, the right clutch operating member 72 is pushed toward the right side clutch 45, and the right side clutch 45 is disengaged. At this time, since the roller 74 on the left operation arm 75 does not come into contact with the cam portion 71a of the cam member 71, the left operation arm 75 is not rotated and the left side clutch 45 remains engaged.

  In the configuration in which the side clutch switching mechanism including the link mechanism 70A and the cam mechanism 70B is provided between the steering handle 53 and the left and right side clutches 45 and 45, when the traveling machine body 2 is turned leftward, the steering handle 53 Begins to rotate counterclockwise, the front arm 58 and the rear arm 59 rotate counterclockwise in plan view via the steering drive mechanism 25, and the front wheels 7 and 7 are steered by the rotation of the front arm 58. The direction is changed to the left via the link mechanism 62, and at the same time, the rod 65 is pushed by the link mechanism 70A and moved rearward by the rotation of the rear arm 59. Due to the backward movement of the rod 65, the rotating arm 66 is rotated counterclockwise in plan view, and the cam member 71 rotates integrally with the rotating arm 66 counterclockwise in plan view around the fulcrum shaft 67. Move.

  When the steering handle 53 is rotated by a predetermined angle or more and the traveling machine body 2 is turned, the cam portion 71a of the cam member 71 rotating counterclockwise in the plan view by the cam mechanism 70B is disengaged from the left side clutch 45. The left bent portion 71b that is the operation start position contacts the roller 74 on the left operating arm 75, and the arc portion 71c contacts the roller 74 on the right operating arm 75. As the steering handle 53 further rotates in the same direction from this state, the cam member 71 pushes the roller 74 on the left operation arm 75 rearward, and the left operation arm 75 rotates clockwise around the arm shaft 73 in plan view. Rotate. The cam portion 73a formed in the lower portion of the arm shaft 73 is also rotated in the same direction by the rotation of the arm shaft 73, and the left clutch operation member 72 is pushed by the cam portion 73a and slides to the left side clutch 45 side. The side clutch 45 is disengaged. Thereby, the power transmission to the left rear wheel 9 is interrupted, the left rear wheel 9 is not driven, and the traveling machine body 2 can easily turn to the left.

  Further, when the traveling machine body 2 is returned from the left-turned state to the straight-ahead state, when the steering handle 53 starts to rotate clockwise, the front arm 58 and the rear arm 59 are turned to the right in plan view via the steering drive mechanism 25. When the front arm 58 is rotated, the steering direction of the front wheels 7 and 7 is changed to the straight traveling state via the link mechanism 62. At the same time, the link mechanism 70A is rotated by the rear arm 59. Then the rod 65 is pulled and moves forward. The forward movement of the rod 65 causes the rotation arm 66 to rotate counterclockwise in a plan view, and the cam member 71 integrally rotates with the rotation arm 66 about the fulcrum shaft 67 clockwise in a plan view. Move. By rotation of the cam member 71, the roller 74 on the left operating arm 75 in a state where the cam mechanism 70B is in contact with the cam portion 71a of the cam member 71 in the vicinity of the left end thereof moves toward the left bent portion 71b of the cam portion 71a. And moves away from the cam portion 71a of the cam member 71 at the left bent portion 71b. Then, when the steering handle 53 is in the straight advance position before the start of rotation, the cam member 71 is in a neutral state, and the left side clutch 45 is again engaged. Thereby, power transmission to the left rear wheel 9 is performed, the left rear wheel 9 is driven, and the traveling machine body 2 is in a straight traveling state.

  On the other hand, when the traveling machine body 2 is turned to the right, when the steering handle 53 starts to rotate clockwise, the front arm 58 and the rear arm 59 rotate clockwise in plan view via the steering drive mechanism 25. As the front arm 58 rotates, the steering direction of the front wheels 7, 7 is changed to the right via the link mechanism 62, and at the same time, the rod 65 is pulled forward by the link mechanism 70A by the rotation of the rear arm 59. Moving. Due to the forward movement of the rod 65, the turning arm 66 is turned clockwise in a plan view, and the cam member 71 integrally rotates with the turning arm 66 around the fulcrum shaft 67 in a plan view. Move.

  When the steering handle 53 is rotated by a predetermined angle or more and the traveling machine body 2 is turned, the cam portion 71a of the cam member 71 rotating clockwise in a plan view by the cam mechanism 70B is hit by the arc portion 71c. The roller 74 on the right operation arm 75 in contact with the roller 74 on the right operation arm 75 at the right bending portion 71d, which is the position where the right side clutch 45 is turned off, comes into contact with the roller 74 on the left operation arm 75. Is held in a non-contact state. As the steering handle 53 further rotates in the same direction from this state, the cam member 71 pushes the roller 74 on the right operation arm 75 rearward, and the right operation arm 75 rotates counterclockwise around the arm shaft 73 in plan view. Rotate. The cam portion 73a formed in the lower portion of the arm shaft 73 is also rotated in the same direction by the rotation of the arm shaft 73, and the right clutch operating member 72 is pushed by the cam portion 73a and slides to the right side clutch 45 side. The side clutch 45 is disengaged. Thereby, the power transmission to the right rear wheel 9 is interrupted, the right rear wheel 9 is not driven, and the traveling machine body 2 can easily turn right.

  Further, when the traveling machine body 2 is returned from the right turning state to the straight traveling state, when the steering handle 53 starts to rotate counterclockwise, the front arm 58 and the rear arm 59 are viewed in plan view via the steering drive mechanism 25. When the front arm 58 is rotated counterclockwise, the steering direction of the front wheels 7 and 7 is changed to the straight traveling state via the link mechanism 62, and at the same time, the rear arm 59 is rotated to link the mechanism. At 70A, the rod 65 is pushed and moves backward. Due to the backward movement of the rod 65, the rotating arm 66 is rotated clockwise in a plan view, and the cam member 71 integrally rotates with the rotating arm 66 counterclockwise in a plan view around the fulcrum shaft 67. Move. By rotation of the cam member 71, the roller 74 on the right operation arm 75 in a state in which the cam mechanism 70B is in contact with the cam portion 71a of the cam member 71 in the vicinity of the right end thereof toward the right bent portion 71d of the cam portion 71a. When the steering wheel 53 moves to the straight position before the rotation starts, the cam member 71 is neutralized and the right side clutch 45 is re-entered by moving from the right bent portion 71d to the arc portion 71c. Become. Thereby, power transmission to the right rear wheel 9 is performed, the right rear wheel 9 is driven, and the traveling machine body 2 is in a straight traveling state.

  As described above, the steering handle 53 and the left and right side clutch 45 are linked and linked by the link mechanism 70A and the cam mechanism 70B, and the cam member 71 that rotates in conjunction with the operation of the steering handle 53 is connected to the cam mechanism 70B. Left and right operation arms 75 and 75 acting via the cam member 71 and the roller 74, and a clutch operation member 72 acting on the left and right side clutches 45 and 45 via the operation arms 75 and 75, In the side clutch switching mechanism of the riding type rice transplanter 1, which includes a rod 65 that connects the steering handle 53 and the cam member 71 to the link mechanism 70 </ b> A and is pushed and pulled by the steering handle 53 to rotate the cam member 71. Since the cam member 71 is formed in an asymmetric shape with respect to the rotation center, the steering hand When the rod 65 is pushed and pulled in the front-rear direction in conjunction with the turning operation of 53, there is a difference in the amount of bending of the rod 65 when the rod 65 is pushed and pulled. The left or right side portion 71 and the left or right operation arms 75 and 75 can be operated at substantially the same time. In other words, during the left turn and the right turn, the side clutch 45 that is on the inner side in the turning direction with respect to a predetermined turning amount of the steering handle 53 in the left or right direction is rotated at substantially the same time, and the operation member is rotated by substantially the same amount. Can be turned on and off. Therefore, the turning performance can be improved by setting the turning radius of the traveling machine body 2 to be the same on the left and right.

  Further, since the fulcrum shaft 67 serving as the rotation center of the cam member 71 is shifted from the left and right center O1 to the left and right sides and the rod 65 is disposed on the left and right sides, the fulcrum shaft 67 is located near the left and right center O1. A universal joint shaft 41 interlockingly connected to the drive unit, for example, the PTO shaft 36 can be disposed, and the degree of freedom of the layout of each part in the traveling machine body 2 can be improved.

  Further, when the steering handle 53 serving as the steering means is rotated, the clutch acting position of the cam member 71 and the fulcrum shaft 67 serving as the rotation center of the cam member 71 when the rod 65 is rotated in the bending direction. Since the distance is longer than the distance between the clutch operating position when the rod 65 is rotated in the pulling direction and the rotation center of the cam member, the amount of bending when the rod 65 is pushed is the amount of elongation when the rod 65 is pulled. However, since the distance from the rotation center of the cam member 71 to the operating position is longer when the rod 65 is pushed, it can be applied longer when pushed even at the same rotation angle. The bending of the rod 65 can be absorbed, and the shift in the on / off operation timing of the side clutch 45 associated with the steering operation during the left turn and the right turn can be eliminated. Further, it is possible to prevent an error from occurring in the left and right turning radius.

The perspective view which showed the whole structure of the riding type rice transplanter provided with the side clutch switching mechanism which concerns on one Example of this invention. The perspective view of a traveling body. The side view of a traveling machine body front part. The figure which shows a side clutch switching mechanism. The lower perspective view of a traveling machine body rear part. The front perspective view of a cam mechanism. The rear view of a cam mechanism. The top view of the cam mechanism in a straight drive state. The top view of a cam member. The top view of the cam mechanism in the left turn start state. The top view of the cam mechanism in a right turn start state.

45 Side clutch 53 Steering handle (steering means)
65 Rod 70A Link mechanism 70B Cam mechanism 71 Cam member 72 Clutch operation member 74 Roller 75 Operation arm

Claims (1)

The steering means and the left and right side clutches are linked and linked by a link mechanism and a cam mechanism, and a cam member that rotates in conjunction with the operation of the steering means is operated to the cam mechanism via the cam member and a roller. Left and right operating arms and a clutch operating member acting on the left and right side clutches via the operating arm, and the steering mechanism and the cam member are connected to the link mechanism and pushed and pulled by the steering means. in the side clutch switching mechanism of the riding rice transplanters having a rod that rotates the cam member, the cam member configured asymmetrical shape with respect to the rotation center, the center of rotation of said cam member, the aircraft left The cam member clutch when the rod is arranged shifted from the center to the left and right sides, the rod is arranged on the left and right other sides, and the rod is pushed and bent when the steering means is rotated. Action position and force The distance between the center of rotation of member, said rod when the pull rotated in a direction, than the distance between the center of rotation of the clutch operating position and the cam member of the cam member, characterized by being configured longer Side clutch switching mechanism for riding rice transplanters.

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