JP3778823B2 - Passenger work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a configuration of a riding type work vehicle such as a riding type rice transplanter, a riding type direct seeder, or an agricultural tractor.
[0002]
[Prior art]
  A passenger work vehicle is equipped with a transmission case at the front, and the right and left lateral sides of the transmission case are steerable right and left front wheels, and the transmission case is extended rearward to the rear of the transmission case. The part extended toTo the rightThere is also a transmission system for the left rear wheel.
[0003]
[0004]
[Problems to be solved by the invention]
  In a passenger work vehicle, it is necessary to set the maximum steering angle of the right and left front wheels to be large so that a small turn can be made at the end of the work site.
  In the passenger work vehicle according to the present invention, a transmission case is provided at the front part, and right and left front side parts of the transmission case are provided to be steerable, and the transmission case is extended rearward. An object of the present invention is to make it possible to set the maximum steering angle of the right and left front wheels to be large.
[0005]
[0006]
[0007]
[Means for Solving the Problems]
[I]
  According to the first aspect of the present invention, the front wheel transmission shaft for transmitting power to the right and left front wheels is disposed in the left-right direction at the front portion of the transmission case, and the rear wheel transmission for transmitting power to the right and left rear wheels. The shaft is arranged in the left-right direction at the rear part of the mission case, and a transmission chain that rotates around the axis in the left-right direction is arranged in the middle part of the mission case.
  In this case, a transmission chain that rotates around the axis in the left-right direction requires a relatively large width in the vertical direction as a space surrounding the transmission chain, but does not require a very large width in the left-right direction. The width of the middle part of the transmission case (the part in which the transmission chain is installed) can be made narrow.
[0008]
  Thus, according to the feature of claim 1, the front wheel transmission shaft for transmitting the power to the right and left front wheels is arranged in the left-right direction at the front portion of the transmission case, and the right and left end portions of the front wheel transmission shaft are arranged. If the right and left front wheels can be steered freely, the right and left front wheels can be connected to the middle part of the transmission case if the width of the middle part of the transmission case (the part where the transmission chain is installed) can be narrowed. The maximum steering angle that is steered until it touches can be set to a large one.
[0009]
[II]
  According to the first aspect of the present invention, the input shaft for transmitting the power of the engine and the front wheel transmission shaft for transmitting the power to the right and left front wheels are arranged in the left-right direction at the front portion of the transmission case, and And the rear-wheel transmission shaft which transmits motive power to the left rear wheel is arrange | positioned toward the left-right direction at the rear part of the transmission case.
  ThisRequestAccording to the characteristics of Claim 1, a normal spur gear or helical gear may be used for the transmission system from the input shaft to the front wheel transmission shaft and the transmission system to the rear wheel transmission shaft via the transmission chain, and the bevel gear is used. (Bevel gears can be used with less bevel gears).
  A passenger work vehicle is often provided with a front-wheel differential mechanism that transmits power to the right and left front wheels. According to the feature of claim 1, the right and left front-wheel transmission shafts that transmit power to the right and left front wheels are provided. A front wheel differential mechanism is provided therebetween, and the power of the input shaft is transmitted to the right and left front wheel transmission shafts via the front wheel differential mechanism.
  Thus, according to the first aspect of the present invention, an ordinary spur gear or helical gear may be used for the power transmission system to the front wheel differential mechanism, and the bevel gear need not be used (the bevel gear can be reduced even if the bevel gear is used). )
[0010]
[III]
  According to the feature of claim 2, as in the case of claim 1, the “action” described in the previous item [I] [II] is provided, and in addition to this, the following “action” is provided.
  In a passenger work vehicle, a transmission mechanism is often arranged inside the transmission case. According to the feature of claim 2, the transmission transmission shaft is arranged in the left-right direction on the lower side of the input shaft in the transmission case, A transmission mechanism is configured between the input shaft and the transmission transmission shaft, and the power of the transmission transmission shaft is transmitted to the front wheel transmission shaft and the rear wheel transmission shaft.
  Thus, according to the feature of claim 2, it is only necessary to use a normal spur gear or a helical gear for the speed change mechanism, and it is not necessary to use a bevel gear (the use of a bevel gear with a small number of bevel gears).
[0011]
[IV]
  According to the feature of claim 3, as in the case of claim 1 or 2, the "action" described in the preceding paragraph [I] [II] [III] is provided, and in addition to this, the following "action" It has.
  As a support structure for the right and left rear wheels, a structure for supporting a rear wheel support case including the right and left rear wheels so as to be freely rollable (around the axial center in the front-rear direction) is conceivable. With this configuration, for example, when the rear wheel support case rolls so that the right side is raised and the left side is lowered, the right rear wheel is inclined to the left inner side while the grounding point of the right rear wheel is moved to the right outer side. The grounding point of the left rear wheel moves inward to the right while the left rear wheel inclines to the left outer side. For example, when both the right and left rear wheels ride on the convex portion of the work area, the entire rear wheel support case is raised, and the riding work vehicle is lifted.
[0012]
  According to the third aspect of the present invention, the right and left transmission cases are independently supported to swing up and down around the left and right axis around the rear of the transmission case, and the right and left transmission cases are extended rearward. The right and left rear wheels are provided at the rear of the right and left transmission cases, and the power of the rear wheel transmission shaft is transmitted to the right and left rear wheels via the right and left transmission cases. It is configured as follows.
[0013]
  Thus, according to the feature of claim 3, the right and left transmission cases swing up and down independently around the axis in the left and right direction, so that the right and left rear wheels move up and down. For example, when the right transmission case (right rear wheel) swings upward and the left transmission case (left rear wheel) swings downward, the unevenness of the work area becomes right and left transmission. Absorbed by the case (right and left rear wheels), the left-right inclination of the riding work vehicle is suppressed.
[0014]
  According to the third aspect of the present invention, the right and left transmission cases swing up and down around the left and right axial centers instead of the front and rear axial cores. And the grounding point of the left rear wheel does not move to the right and left inside, right and left outside, and the right and left rear wheels do not tilt to the right and left inside, right and left outside. . As a result, the power of the right and left rear wheels can be transmitted to the work site (the contact points of the right and left rear wheels) without waste without being affected by the unevenness of the work site.
[0015]
  According to the feature of claim 3, since the right and left transmission cases swing up and down independently around the axis in the left and right direction, for example, even if both the right and left rear wheels ride on the convex portion of the work place, As the right and left transmission cases (right and left rear wheels) swing upward, the situation where both the right and left rear wheels ride on the convex portion of the work area is absorbed. The situation where the car is lifted is suppressed.
[0016]
[0017]
[V]
  According to the feature of claim 4, the “action” described in the preceding items [I] to [IV] is provided as in the case of any one of claims 1 to 3. It has a special “action”.
  A passenger work vehicle may be equipped with right and left side clutches that can independently transmit and block power to the right and left rear wheels.For example, when turning to the right, operate the right side clutch to the cutoff side. Then, by turning off the power to the right rear wheel, a small turn to the right can be easily performed.
[0018]
  Claim 4According to this feature, right and left side clutches capable of independently transmitting and interrupting power to the right and left rear wheels are provided concentrically with the front wheel differential mechanism or on the rear wheel transmission shaft. by this,Claim 4According to the characteristics, it is only necessary to use a normal spur gear or a helical gear in the power transmission system to the right and left side clutches, and it is not necessary to use a bevel gear (the use of a bevel gear or a small number of bevel gears) .
[0019]
[VI]
  According to the feature of claim 5, as in the case of claim 4, the “action” described in the preceding paragraphs [I] to [V] is provided, and in addition to this, the following “action” is provided.
  Claim 5According to the features, in addition to the right and left side clutch that can independently transmit and shut off the power to the right and left rear wheels, there is a side brake that can brake the right and left rear wheels independently. Yes.
[0020]
  to thisTherefore, claim 5For example, when turning right (for example, turning left), the right (left) side clutch is operated to the disengagement side to cut off the power to the right (left) rear wheel, and the right ( By operating the left side brake to the braking side and braking the right (left) rear wheel, a small turn to the right (left) can be performed more easily.
[0021]
[VII]
  According to the feature of claim 6, as with any one of claims 1 to 5, the "action" described in the previous items [I] to [VI] is provided. It has a special “action”.
  The passenger work vehicle has a brake that can brake the front and rear wheels.Claim 6According to the above feature, a recess is formed on the outer surface of the intermediate portion of the transmission case, and the brake is provided in the recess.
[0022]
  Claim 6Like the featuresMiWhen the recess is formed on the outer surface of the intermediate portion in the case, the intermediate portion in the mission case is reinforced by the rib effect by the wall portion or the like that forms the periphery of the recess. As a result, as described in the preceding item [I], even if the width of the middle part of the mission case is narrow, the strength of the middle part of the mission case can be easily secured. Further, by providing the brake in the recess, it is possible to avoid a state in which the brake protrudes from the outer surface of the intermediate portion of the transmission case.
[0023]
[VIII]
  According to the feature of claim 7, as in the case of claim 6, the “action” described in the previous items [I] to [VII] is provided, and in addition to this, the following “action” is provided. .
  Claim 7According to the featuresPrevious item [VII]When a recess is formed on the outer surface of the intermediate portion of the transmission case and the brake is provided in the recess, a sprocket gear that meshes with the transmission chain and rotates together is provided to brake the sprocket gear. In addition, a brake is configured.
[0024]
  Since it is difficult to configure the brake to apply braking directly on the transmission chain,Claim 7By providing the sprocket gear that meshes with the transmission chain and rotates together as described above, the operation of the transmission chain can be taken out as rotation around one axis of the sprocket gear. ThisClaim 7According to the above feature, the brake can be configured so as to brake the sprocket gear rotating around the uniaxial core, so that a relatively general brake can be used.
[0025]
[IX]
  According to the feature of claim 8, as in the case of claim 7, the “action” described in the previous items [I] to [VIII] is provided, and in addition to this, the following “action” is provided.
  Previous section [VIII]When the sprocket gear that meshes with the transmission chain is provided, the transmission chain may be separated from the sprocket gear due to vibration of the transmission chain or the like.
  Claim 8According to the characteristics ofAnd legendSince the guide member that prevents the moving chain from being separated from the sprocket gear is provided, the transmission chain may be separated from the sprocket gear due to the vibration of the transmission chain, etc., and braking by the brake does not reach the front and rear wheels. can avoid.
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
DETAILED DESCRIPTION OF THE INVENTION
[1]
  1 and 2 show the entire riding rice transplanter as an example of a riding work vehicle.
  As shown in FIGS. 3 and 4, the transmission case 1 is arranged in the front left and right center CL so as to extend in the front-rear direction, and the front wheels are supported on the right and left lateral sides of the front lower portion of the transmission case 1. The case 2 is connected and extends right and left (the front wheel support case 2 does not move up and down with respect to the transmission case 1). A support case 3 is rotatably supported around a longitudinal axis P1 at the end of the front wheel support case 2, and right and left front wheels 4 are supported by the support case 3, and the right and left front wheels 4 are support cases. 3 is configured to be steered right and left around the vertical axis P1 (around a transmission shaft 74 in FIG. 6 to be described later).
[0032]
  As shown in FIGS. 3 and 4, boss portions 1 a are formed on the right and left lateral sides of the rear end of the transmission case 1 so as to protrude right and left lateral sides. However, it is supported so that it can swing up and down independently around the axis P2 in the left-right direction of the boss 1a. The right and left transmission cases 5 extend rearward from the boss 1a, and the right and left rear wheels 6 are supported at the rear of the right and left transmission cases 5, and the right and left rear wheels 6 are The steering operation is not performed.
[0033]
  As shown in FIGS. 1 and 2, a support frame 7 formed by bending a flat plate into a box shape is connected to the right and left boss portions 1a, and brackets 7a are fixed to the left and right of the rear upper end of the support frame 7. One support shaft 8 is installed over the right and left brackets 7a. Suspension springs 9 are attached across the right and left transmission cases 5 and the right and left ends of the support shaft 8. A right and left torsion bar 10 bent in a crank shape in plan view (see FIG. 4) is provided, and one end of the torsion bar 10 is connected to the rear portion of the transmission case 1 so as not to rotate. Are attached to the right and left transmission cases 5.
[0034]
  As a result, the load applied to the right and left rear wheels 6 is mainly supported by the suspension spring 9. When the right and left transmission cases 5 swing upward, the elastic resistance of the suspension spring 9 is increased to the right. In addition to being applied to the left transmission case 5, a portion of the torsion bar 10 fixed to the transmission case 1 is twisted, and the elastic resistance of the torsion bar 10 is applied to the right and left transmission cases 5. When a force to displace the right and left transmission cases 5 in the left-right direction is applied, the torsion bar 10 suppresses the displacement of the right and left transmission cases 5 in the left-right direction.
[0035]
[2]
  Next, the support structure of the seedling planting apparatus 41 and the seedling planting apparatus 41 will be described.
  As shown in FIGS. 1, 2, and 3, the right and left brackets 7 b are fixed to the lower end of the rear portion of the support frame 7. The right and left lower links 43 are supported so as to be swingable up and down, and a support member 44 is connected to the rear ends of the top link 42 and the lower link 43. A single-acting lift cylinder 45 is supported on the support shaft 8 so as to swing up and down, and a cylinder rod 45a of the lift cylinder 45 is provided.IsThe support member 44 is connected to the support rubber 44 via a suspension rubber 46 and a C-shaped connection member 47.
[0036]
  As shown in FIGS. 1 and 2, a four-row type seedling planting apparatus 41 is connected to a lower part of a support member 44 around a front and rear axis so as to be capable of rolling. The seedling planting device 41 includes a feed case 48 connected to the support member 44, right and left planting transmission cases 49 extending rearward, and planting that is rotationally driven on the right and left sides of the planting transmission case 49. A case 60, a pair of planting arms 50 supported by the planting case 60, a seedling platform 51 provided with four seedling resting surfaces and driven to reciprocate laterally in the horizontal direction, and a grounding float 52 supported so as to be movable up and down. Etc. are provided.
[0037]
  As shown in FIGS. 3 and 4, the PTO shaft 53 extends rearward and passes through the lower part inside the support frame 7 from the position shifted to the right side from the left and right center CL in the upper part of the mission case 1. A universal joint 54 is provided at the end of the PTO shaft 53 in the vicinity of the lower portion between the left bracket 7b and the left bracket 7b. A PTO shaft 55 is connected across the universal joint 54 of the PTO shaft 53 and the universal joint 54 of the input shaft 48 a of the feed case 48. With the above structure, the power of the planting clutch 32 described in [4] and [5], which will be described later, is transmitted to the seedling planting device 41 via the PTO shafts 53 and 55, and the seedling platform 51 reciprocates. Along with being driven laterally, the planting arm 50 alternately takes out seedlings from the lower part of the seedling platform 51 and plantes them on the rice field.
[0038]
[3]
  Next, the structure near the engine 16 and the hydrostatic continuously variable transmission 11 will be described.
  As shown in FIGS. 1, 5, and 6, the hydrostatic continuously variable transmission 11 is positioned on the left side of the front upper portion of the mission case 1 on the left side of the left and right center CL (see FIGS. 2 and 4). So that they are connected. The input shaft 11a and the output shaft 11b of the hydrostatic continuously variable transmission 11 are located at substantially the same height in the left-right direction, and the input shaft 11a of the hydrostatic continuously variable transmission 11 projects leftward. The output shaft 11 b of the hydrostatic continuously variable transmission 11 is located inside the mission case 1. An input pulley 12 and a cooling fan 13 are fixed to the input shaft 11 a of the hydrostatic continuously variable transmission 11.
[0039]
  As shown in FIGS. 1 and 5, an engine support frame 14 facing obliquely upward and forward is connected to the front portion of the transmission case 1, and a substantially horizontal engine support base 15 is located slightly to the left of the left and right center CL. In this way, it is connected to the engine support frame 14 (see FIG. 4). The crankcase 16a of the engine 16 is supported by the engine support 15 via the anti-vibration rubber 17, the output shaft 16c of the engine 16 protrudes leftward in the left-right direction, and the cylinder 16b of the engine 16 is obliquely rearward and upward It is arranged so as to be inclined.
[0040]
  As shown in FIG. 5, the output pulley 18 is fixed to the output shaft 16 c of the engine 16, and the transmission belt 19 is wound around the output pulley 18 and the input pulley 12. A tension arm 20 is swingably supported around the horizontal axis P3 of the engine support frame 14, a tension pulley 20a is provided at the tip of the tension arm 20, and the tension pulley 20a is pressed against the transmission belt 19. The tension arm 20 is urged clockwise by the spring 21 in FIG.
[0041]
[4]
  Next, the transmission system to the seedling planting device 41 and the inter- stock change mechanism 30 will be described.
  As shown in FIGS. 6 and 7, in the transmission case 1, the power of the output shaft 11b of the hydrostatic continuously variable transmission 11 is arranged in the left-right direction and connected to the output shaft 11b. 24, a transmission gear 25 externally fitted to the transmission shaft 24 via a one-way clutch 33, a transmission gear pair 27, a transmission gear 28, a transmission gear 28, and a transmission gear 26 externally fitted to a transmission shaft 26 arranged in the left-right direction. Transmission shaft 29 to which the gear 28 is fixed (arranged in the left-right direction and rotatable relative to the transmission shaft 24), the inter- stock change mechanism 30, the torque limiter 31, the planting clutch 32, and the item [2] It is transmitted to the seedling planting device 41 via the PTO shafts 53 and 55 (see FIG. 3).
[0042]
  As shown in FIGS. 7 and 8, the transmission shafts 23 and 29 are supported from the right outer wall portion 1 b of the transmission case 1 so as to protrude outward from the front upper portion of the transmission case 1. Three transmission gears 21 are externally fitted to the projecting portion of the transmission shaft so as to be integrally rotatable with a key structure, and three transmission gears 22 are externally fitted to the projection portion of the transmission shaft 23 so as to be relatively rotatable. , 22 are engaged with each other to form three sets of transmission gears 21 and 22. Three cam balls 34 that are movable in the radial direction of the transmission shaft 23 are disposed in each of the transmission gears 22, and a shift rod 35 that is slidable in the axial direction of the transmission shaft 23 is provided. As aboveStockAn interval changing mechanism 30 is configured.
[0043]
  As shown in FIGS. 7 and 8, the vertical wall 1 c is formed on the right outer wall 1 b of the mission case 1.AndThe stock change mechanism 30 is surrounded by the vertical wall portion 1 c of the mission case 1, and the vertical wall portion 1 c of the mission case 1 is provided with a lid portion 57 that is detachable by a bolt 56. The shift rod 35 is slidably supported by the lid portion 57, and a detent ball 58 that holds the shift rod 35 at three positions is provided on the lid portion 57.
[0044]
  Accordingly, as shown in FIGS. 7 and 8, when the shift rod 35 is slid and the large diameter portion at the tip of the shift rod 35 is positioned on the cam ball 34 corresponding to the desired transmission gear 22, the shift rod 35. The cam ball 34 is pushed out in the radial direction of the transmission shaft 23 by the large-diameter portion, and enters into the opening of the transmission shaft 23 and the desired transmission gear 22, and the desired transmission gear 22 is fixed to the transmission shaft 23. In this state, the power of the transmission shaft 29 is transmitted to the transmission shaft 23 via the desired transmission gear 22. Thus, by positioning the large-diameter portion of the shift rod 35 on the desired cam ball 34 (transmission gear 22), the power transmitted from the transmission shaft 29 to the transmission shaft 23 is shifted in three stages, and the planting arm 50 (refer FIG.1 and FIG.2) changes the space | interval of the seedling planted to a rice field in three steps.
[0045]
  As shown in FIG. 9, the inter- stock change mechanism 30 can be opened by removing the shift rod 35 together with the cover portion 57. Thereby, the transmission gears 21 and 22 are removed from the transmission shafts 23 and 29, and the transmission gears 21 and 22 having different numbers of teeth are attached to the transmission shafts 23 and 29, so that the stock change mechanism having different specifications with different transmission ratios is obtained. It can be changed to 30.
[0046]
[5]
  Next, the torque limiter 31 and the planting clutch 32 will be described.
  As shown in FIGS. 7 and 8, the output shaft 36 is arranged in the front-rear direction at a position deviated to the right from the left-right center CL at the upper portion of the mission case 1, and is connected to the output shaft 36 outside the mission case 1. A PTO shaft 53 (see FIGS. 3 and 4) is connected. In the transmission case 1, a cylindrical shaft 37 is externally fitted to the output shaft 36 so as to be relatively rotatable. A bevel gear 38 externally fitted to the cylindrical shaft 37 is rotatably attached to a bevel gear 39 fixed to the transmission shaft 23. Biting. The engaging portion 40 is externally fitted to the cylindrical shaft 37 in a spline structure so as to be integrally rotatable and slidable, the spring receiving rotary portion 59 is fixed to the cylindrical shaft 37, and a spring that biases the engaging portion 40 to the bevel gear 38. 61 is provided between the engaging portion 40 and the spring support rotating portion 59. The torque limiter 31 is configured as described above.
[0047]
  As shown in FIGS. 7 and 8, the engaging portion 62 is externally fitted to the output shaft 36 in a spline structure so as to be integrally rotatable and slidable, and a spring 63 that urges the engaging portion 62 against the spring receiving rotating portion 59 is provided. It is provided and the planting clutch 32 is comprised.
  The state shown in FIGS. 7 and 8 is a state in which a notch formed in the outer peripheral portion of the engaging portion 40 enters and engages with the convex portion 38a of the bevel gear 38, and the convex portion 62a of the engaging portion 62. Is in the engagement position where it enters into and engages with the opening of the spring receiver rotating portion 59. In this state, the power of the stock change mechanism 30 is transmitted to the PTO shaft 53 via the bevel gear 38, the engaging portion 40, the cylindrical shaft 37, the spring support rotating portion 59, the engaging portion 62, and the output shaft 36.
[0048]
  In the state described above, when a large load is applied to the seedling planting device 41, the engagement portion 40 slides away from the bevel gear 38 against the urging force of the spring 61, as shown by the one-dot chain line in FIG. Power is interrupted between 38 and the engaging part 40, and the seedling planting apparatus 41 stops. When the large load applied to the seedling planting device 41 disappears, the engaging portion 40 slides to the bevel gear 38 by the biasing force of the spring 61, and the notch portion of the engaging portion 40 enters and engages the convex portion 38a of the bevel gear 38. Then, the state automatically returns to the state where the power is transmitted, and the seedling planting device 41 operates.
[0049]
  As shown in FIG. 10, when the operating rod 64 is slid to the left in FIG. 10, the operating rod 64 enters the cam surface formed on the side of the engaging portion 62, and the engaging portion 62 moves to a predetermined phase ( The planting arm 50 (see FIG. 1) is slid at a phase positioned above the pad surface and is separated from the spring support rotating portion 59. Thereby, power is interrupted between the spring receiver rotating part 59 and the engaging part 62, and the seedling planting device 41 stops.
[0050]
[6]
  Next, the transmission system to the right and left front wheels 4 will be described.
  As shown in FIGS. 6 and 7, transmission gears 65 and 66 are fixed to the transmission shaft 24, and a shift gear 67 is externally fitted to the transmission shaft 26 so as to be rotatable and slidable integrally with the transmission shaft 26 by a spline structure. As shown in FIGS. 6 and 11, the right and left front wheel transmission shafts 68 are arranged in the left-right direction across the mission case 1 and the right and left front wheel support cases 2. A front wheel differential mechanism 69 is provided at the abutting portion of the right and left front wheel transmission shafts 68.
[0051]
  As shown in FIGS. 11 and 12, the front wheel differential mechanism 69 includes an outer case 69a, a pair of pinion gears 69b rotatably supported by the outer case 69a, and a pair of side gears 69c engaged with the pinion gears 69b. The right and left front gears 68c are connected to the right and left side gears 69c. A cylindrical shaft 70 connected to the outer case 69 a of the front wheel differential mechanism 69 is fitted on the right front wheel transmission shaft 68 so as to be relatively rotatable, and a transmission gear 71 fixed to the cylindrical shaft 70 is attached to the transmission shaft 26. It meshes with a fixed transmission gear 72.
[0052]
  6, 7 and 11, the shift gear 67 is slid and engaged with the transmission gears 65 and 66, so that the power of the transmission shaft 24 is shifted in two stages and transmitted to the transmission shaft 26 as shown in FIGS. Is done. The power of the transmission shaft 26 includes transmission gears 72 and 71, a cylindrical shaft 70, a front wheel differential mechanism 69, right and left front wheel transmission shafts 68, a bevel gear mechanism 73 built in the front wheel support case 2, the front wheel support case 2 and the support case 3. The power is transmitted to the right and left front wheels 4 through the transmission shaft 74, the bevel gear mechanism 75 built in the support case 3, and the axle 4 a.
[0053]
  As shown in FIGS. 11 and 12, a shift member 76 is externally fitted to the right front wheel transmission shaft 68 so as to be integrally rotatable and slidable with the right front wheel transmission shaft 68 by a key structure. A spring 77 biasing away from 70 and an operation shaft 78 for sliding the shift member 76 to the cylindrical shaft 70 are provided. Thus, as shown in FIG. 11, when the shift member 76 is separated from the end of the cylindrical shaft 70, the front wheel differential mechanism 69 is in the unlocked state, and the operation shaft 78 is rotated as shown in FIG. When operated, the shift member 76 is slid to the left in the drawing and engaged with the end of the cylindrical shaft 70, the front wheel differential mechanism 69 enters the differential lock state.
[0054]
[7]
  Next, the transmission system to the right and left rear wheels 6 will be described.
  As shown in FIGS. 13 and 14, the right and left rear wheel transmission shafts 79 are arranged in the left-right direction across the boss portion 1a of the transmission case 1 and the right and left transmission cases 5, and the right and left The right and left transmission cases 5 are supported on the left rear wheel transmission shaft 79 (axial axis P2 in the left-right direction) so as to be swingable up and down. As shown in FIGS. 6 and 11, a sprocket gear 80 is fixed to the cylindrical shaft 70, and as shown in FIGS. 13 and 14, in the abutting portion of the right and left rear wheel transmission shaft 79 inside the transmission case 1, A sprocket gear 81 is externally fitted so as to be relatively rotatable, and a transmission chain 82 is wound around the sprocket gears 80 and 81.
[0055]
  As shown in FIGS. 13 and 14, right and left shift members 83 are externally fitted to the right and left rear wheel transmission shafts 79 in a spline structure so as to be integrally rotatable and slidable. A plurality of friction plates 84 are disposed between the boss portion 1 a of the transmission case 1 and a spring 85 that urges the right and left shift members 83 to the sprocket gear 81. A shift arm 88 for sliding the right and left shift members 83 to the friction plate 84 is provided, and a steering handle 89 (see FIGS. 1 and 5) for steering the right and left front wheels 4 is provided. The left shift arm 88 is mechanically linked. As a result, right and left side clutches 86 are configured between the sprocket gear 81 and the right and left shift members 83, and between the right and left shift members 83 and the friction plate 84, the right and left side clutches 86 are configured. A side brake 87 is configured.
[0056]
  The state shown in FIGS. 13 and 14 is a state in which the right and left front wheels 4 are steered within the range of the right and left set angles from the straight position and the straight position, and the right and left shift members 83 is a state engaged with the sprocket gear 81 (a state where the right and left side clutches 86 are operated to the transmission side and the right and left side brakes 87 are operated to the release side). The power of the cylindrical shaft 70 (see FIGS. 6 and 11) is internally contained in the transmission chain 82, the sprocket gear 81, the right and left shift members 83, the right and left rear wheel transmission shafts 79, and the right and left transmission cases 5. It is transmitted to the right and left rear wheels 6 through the transmission chain 90, the transmission shaft 91, and the axle 6a.
[0057]
  For example, when the steering handle 89 is operated to the right and the right and left front wheels 4 are steered to the right beyond the right set angle, the right shift arm 88 resists the spring 85 and the right shift member. 14 is slid to the right in FIG. 14 to move away from the sprocket gear 81 and press the right friction plate 84. As a result, the right rear wheel 6 is braked (the right side brake 87 is braked) in a state where the power to the right rear wheel 6 is cut off (the right side clutch 86 is operated to the cut-off side). Operated to the side).
[0058]
  As shown in FIGS. 6 and 14, a recess 1d that is open laterally outward is formed on the right outer surface of the intermediate portion of the mission case 1, and the wall 1e and the boss 1f that form the periphery of the recess 1d are the mission. It is formed integrally with the case 1, and a boss portion 1 f is formed integrally with the left outer surface of the intermediate portion of the mission case 1. As shown in FIGS. 14 and 15, the intermediate shaft 92 is rotatably supported across the right and left boss portions 1 f, and the sprocket gear 92 a formed on the intermediate shaft 92 is connected to the transmission chain 82 from the inside of the winding path. The brake 94 that is engaged and capable of braking the intermediate shaft 92 is disposed so as to enter the recess 1d.
[0059]
  6, 14, and 15, the guide chain 93 that prevents the transmission chain 82 from being separated from the sprocket gear 92 a is wound around the transmission chain 82 so that the transmission chain 82 is sandwiched between the sprocket gear 92 a and the guide member 93. It is arranged outside the turning path. With the structure described above, the front wheel 4 and the rear wheel 6 are braked via the intermediate shaft 92, the sprocket gear 92a, and the transmission chain 82 by operating the brake 94 to the braking side.
[0060]
[First Alternative Embodiment of the Invention]
  The right and left side clutches 86 and the right and left side brakes 87 of [Embodiment of the invention] described above may be disposed on the left front wheel transmission shaft 68 as shown in FIGS.
  As shown in FIG. 16 and FIG.,A front wheel differential mechanism 69 is provided at the abutting portion of the right and left front wheel transmission shafts 68, and a shift member 76 is fitted on the right front wheel transmission shaft 68 so that it can rotate and slide integrally with the right front wheel transmission shaft 68 by a key structure. A spring 77 that biases the shift member 76 away from the outer case 69a of the front wheel differential mechanism 69 and an operating shaft 78 that slides the shift member 76 onto the outer case 69a of the front wheel differential mechanism 69 are provided. . As a result, when the shift member 76 is separated from the outer case 69a of the front wheel differential mechanism 69, the front wheel differential mechanism 69 is in the unlocked state, and the operation shaft 78 is rotated to move the shift member 76 to the left side of the page. When the sliding operation is performed to engage the outer case 69a of the front wheel differential mechanism 69, the front wheel differential mechanism 69 enters the differential lock state.
[0061]
  As shown in FIGS. 16 and 17, the cylindrical shaft 70 connected to the outer case 69 a of the front wheel differential mechanism 69 is externally fitted to the left front wheel transmission shaft 68 so as to be relatively rotatable.AndA transmission gear 96 fixed to the cylindrical shaft 70 is engaged with the transmission gear 72. The right and left cylindrical shafts 95 are externally fitted to the cylindrical shaft 70 so as to be relatively rotatable, and the right and left shift members 97 are externally fitted to the right and left cylindrical shafts 95 by a key structure so as to be integrally rotatable and slidable. A plurality of friction plates 98 are disposed between the right and left cylindrical shafts 95 and the transmission case 1. As a result, right and left side clutches 86 are formed between the transmission gear 96 and the right and left shift members 97, and between the right and left shift members 97 and the friction plates 98, the right and left side clutches 86 are formed. A side brake 87 is configured.
[0062]
  As shown in FIGS. 16 and 17, the right and left rear wheel transmission shafts 79 are arranged in the left-right direction across the boss portion 1a of the transmission case 1 and the right and left transmission cases 5. The right and left transmission cases 5 are supported on the left rear wheel transmission shaft 79 (axial axis P2 in the left-right direction) so as to be swingable up and down. An intermediate shaft 99 is supported on the transmission case 1, and a transmission gear 100 externally fitted on the intermediate shaft 99 so as to be relatively rotatable is engaged with a transmission gear 101 fixed to the right and left rear wheel transmission shafts 79. A transmission chain 102 is wound around a sprocket gear 95 a provided on the right and left cylindrical shafts 95 and a sprocket gear 100 a fixed to the transmission gear 100.
[0063]
  16 and 17, the power of the transmission shaft 26 is transmitted to the right and left front wheels 4 through the transmission gears 72 and 96, the cylindrical shaft 70, and the front wheel differential mechanism 69. The state shown in FIGS. 16 and 17 is a state in which the right and left front wheels 4 are steered within the range of the right and left set angles from the straight position and the straight position, and the right and left shift members 97 is engaged with the transmission gear 96 (the right and left side clutches 86 are operated to the transmission side, and the right and left side brakes 87 are operated to the release side). As a result, the power of the transmission gear 96 is transferred to the right and left shift members 97, the transmission chain 102, the right and left rear wheel transmission shafts 79, and the right and left transmission gears 5 via the transmission chains 90 built in the right and left transmission cases 5. It is transmitted to the left rear wheel 6.
[0064]
  exampleIf youWhen the vertical handle 89 is operated to the right and the right and left front wheels 4 are steered to the right beyond the right set angle, the right shift member 97 is slid to the right in FIG. The right friction plate 98 is pressed away from the transmission gear 96. As a result, the right rear wheel 6 is braked (the right side brake 87 is braked) in a state where the power to the right rear wheel 6 is cut off (the right side clutch 86 is operated to the cut-off side). Operated to the side).
[0065]
[Second Embodiment of the Invention]
  The right and left side clutches 86 and the right and left side brakes 87 of [Embodiment of the Invention] and [First Alternative Embodiment of the Invention] are connected to the transmission case 1 as shown in FIGS. You may provide in the intermediate part. As shown in FIGS. 18 and 19, a front wheel differential mechanism 69 is provided at the abutting portion of the right and left front wheel transmission shafts 68 inside the transmission case 1, and is fixed to an outer case 69 a of the front wheel differential mechanism 69. The transmission gear 103 is engaged with the transmission gear 72.
[0066]
  As shown in FIGS. 18 and 19, a shift member 76 is externally fitted to the left front wheel transmission shaft 68 so as to be integrally rotatable and slidable with the left front wheel transmission shaft 68 by the key structure, and the shift member 76 is moved to the front wheel differential mechanism. A spring 77 that urges the outer case 69a away from the outer case 69a and an operating shaft 78 that slides the shift member 76 onto the outer case 69a of the front wheel differential mechanism 69 are provided. Thus, when the shift member 76 is separated from the outer case 69a of the front wheel differential mechanism 69, the front wheel differential mechanism 69 is in the differential lock release state, and the operation shaft 78 is rotated to move the shift member 76 rightward in the drawing. When the sliding operation is performed to engage the outer case 69a of the front wheel differential mechanism 69, the front wheel differential mechanism 69 enters the differential lock state.
[0067]
  As shown in FIGS. 18 and 19, a recess 1d that is open laterally outward is formed on the right outer surface of the intermediate portion of the mission case 1, and the wall 1e and the boss 1f that form the periphery of the recess 1d are the mission. It is formed integrally with the case 1, and a boss portion 1 f is formed integrally with the left outer surface of the intermediate portion of the mission case 1. The intermediate shaft 104 is rotatably supported across the right and left boss portions 1f, the transmission gear 105 fixed to the intermediate shaft 104 is engaged with the transmission gear 103, and the brake 94 capable of braking the intermediate shaft 104 is recessed. It is arranged so as to enter 1d.
[0068]
  As shown in FIGS. 18 and 19, intermediate shafts 106 and 107 are arranged in the intermediate portion of the transmission case 1, and a transmission gear 108 is fitted on the intermediate shaft 106 so as to be relatively rotatable, and the transmission gear 108 is transmitted to the transmission gear 108. 105 bites. Right and left shift gears 109 are externally fitted to the intermediate shaft 106 so as to be relatively rotatable, and a plurality of friction plates 110 are disposed between the right and left shift gears 109 and the transmission case 1. As a result, the right and left side clutches 86 are configured between the transmission gear 108 and the right and left shift gears 109, and between the right and left shift gears 109 and the friction plate 110.RightAnd the left side brake 87 is comprised.
[0069]
  As shown in FIGS. 18 and 19, the right and left rear wheel transmission shafts 79 are arranged in the left-right direction across the boss portion 1a of the transmission case 1 and the right and left transmission cases 5, and the right and left The right and left transmission cases 5 are supported on the left rear wheel transmission shaft 79 (axial axis P2 in the left-right direction) so as to be swingable up and down. A transmission gear pair 111 that is externally fitted to the intermediate shaft 107 so as to be relatively rotatable is engaged with a transmission gear 101 that is fixed to the right and left rear wheel transmission shafts 79, and the right and left transmission gear pairs 111 are And always meshed with the left shift gear 109.
[0070]
  18 and 19, the power of the transmission shaft 26 is transmitted to the right and left front wheels 4 through the transmission gear 103 and the front wheel differential mechanism 69. The state shown in FIGS. 18 and 19 is a state in which the right and left front wheels 4 are steered within the range of the right and left set angles from the straight position and the straight position, and the right and left shift gears 109 are operated. Is engaged with the transmission gear 108 (a state in which the right and left side clutches 86 are operated to the transmission side and the right and left side brakes 87 are operated to the release side). As a result, the power of the transmission gear 103 is transmitted to the transmission gears 105 and 108, the right and left shift gears 109, the right and left transmission gear pairs 111, the right and left rear wheel transmission shafts 79, and the right and left transmission cases 5. It is transmitted to the right and left rear wheels 6 via an internally mounted transmission chain 90.
[0071]
  For example, when the steering handle 89 is operated to the right and the right and left front wheels 4 are steered to the right beyond the right set angle, the right shift gear 109 is slid to the right in FIG. Thus, the right friction plate 110 is pressed while being separated from the transmission gear 108 and engaged with the right transmission gear pair 111. As a result, the right rear wheel 6 is braked (the right side brake 87 is braked) in a state where the power to the right rear wheel 6 is cut off (the right side clutch 86 is operated to the cut-off side). Operated to the side). By operating the brake 94 to the braking side, the front wheel 4 and the rear wheel 6 are braked via the intermediate shaft 104, the transmission gears 105, 103, 108, the right and left shift gears 109, and the right and left transmission gear pairs 111. It takes.
[0072]
[Third Another Embodiment of the Invention]
  In the above-mentioned [Embodiment of the invention] [First alternative embodiment of the invention] and [Second alternative embodiment of the invention], the right and left side brakes 87 are eliminated, and the right and left side clutches 86 are eliminated. You may comprise so that only may be provided. Conversely, the right and left side clutches 86 may be eliminated, the right and left side brakes 87 may be provided, and a rear wheel differential mechanism (not shown) may be provided.
[0073]
  In the above-described [Embodiment of the invention], the transmission chain 82 shown in FIGS. 6 and 14 may be wound around the transmission shaft 26 and the sprocket gear 81. In [First Different Embodiment of the Invention], the transmission chain 102 shown in FIGS. 16 and 17 may be wound around the transmission shaft 26 and the sprocket gear 100a.
  The present invention can be applied not only to a riding type rice transplanter but also to a four-wheel drive type riding type direct seeding machine, a four-wheel drive type agricultural tractor, a riding type lawn mower, etc. that are provided with a direct sowing device at the rear part thereof.
[0074]
【The invention's effect】
  According to the features of claim 1, in a passenger work vehicleRightAnd a front wheel transmission shaft that transmits power to the left front wheel is arranged in the left-right direction at the front part of the transmission case, and a rear wheel transmission shaft that transmits power to the right and left rear wheels in the left-right direction at the rear part of the transmission case A transmission chain that rotates around the axis in the left-right direction is arranged in the middle part of the transmission case. As a result, when the right and left front wheels are steerable at the right and left ends of the front wheel transmission shaft, the width of the middle part of the transmission case (the part in which the transmission chain is installed) should be made narrow. The maximum steering angle for steering the right and left front wheels until they contact the middle part of the transmission case can be set to a large one, and the turning performance of the passenger work vehicle can be improved. did it.
[0075]
  According to the first aspect of the present invention, the input shaft for transmitting the power of the engine and the front wheel transmission shaft for transmitting the power to the right and left front wheels are arranged in the left-right direction at the front portion of the transmission case, and Since the rear wheel transmission shaft that transmits power to the left rear wheel is disposed in the left-right direction at the rear part of the transmission case, the input shaft is connected to the rear wheel transmission shaft via the front wheel transmission shaft and the transmission chain. A normal spur gear or helical gear need only be used in the transmission system, and it is not necessary to use a bevel gear (the bevel gear can be used with fewer bevel gears), simplifying the structure and reducing production costs. It became advantageous in terms of.
  According to the first aspect of the present invention, when a front wheel differential mechanism for transmitting power to the right and left front wheels is provided, an ordinary flat gear or helical gear may be used for the power transmission system to the front wheel differential mechanism. There is no need to use it (even if a bevel gear is used, fewer bevel gears are required), which is advantageous in terms of simplifying the structure and reducing production costs.
[0076]
  According to the feature of claim 2, as in the case of claim 1, the “effect of the invention” of the above-mentioned claim 1 is provided. In addition to the “effect of the invention”, the following “effect of the invention” is provided. It has.
  According to the second aspect of the present invention, when the speed change mechanism is arranged inside the transmission case, it is only necessary to use a normal spur gear or a helical gear for the speed change mechanism, and it is not necessary to use the bevel gear (using the bevel gear). Even fewer bevel gears are better), which is advantageous in terms of simplified structure and reduced production costs.
[0077]
  According to the feature of claim 3, the “effect of the invention” of claim 1 or 2 is provided as in the case of claim 1 or 2, and in addition to the “effect of invention”, the following “ The effect of the invention is provided.
  According to the third aspect of the present invention, the power of the right and left rear wheels is not wasted without being affected by the unevenness of the work place, while suppressing the right and left inclination of the passenger work vehicle, and the work ground (the right and left rear wheels). The road performance of the passenger work vehicle could be improved.
  According to the features of claim 3And examplesFor example, even if both the right and left rear wheels ride on the convex part of the work site, the right and left transmission cases (right and left rear wheels) swing upward, Since the state where both ride on the convex portion of the work place is absorbed and the state where the riding work vehicle is lifted is suppressed, the traveling performance of the riding work vehicle can also be improved in this respect.
[0078]
[0079]
  According to the feature of claim 4, the “effect of the invention” of the above-described claims 1 to 3 is provided as in the case of any one of claims 1 to 3. The following “effects of the invention” are provided.
  Claim 4According to the features, when equipped with right and left side clutches that can independently transmit and block power to the right and left rear wheels, the power transmission system to the right and left side clutches has a normal spur gear. And a helical gear can be used, and it is not necessary to use a bevel gear (the bevel gear can be used with few bevel gears), which is advantageous in terms of simplification of the structure and reduction of production costs. It was.
[0080]
  According to the feature of claim 5, as in the case of claim 4, the “effect of the invention” of the above-mentioned claim 4 is provided. In addition to this “effect of the invention”, the following “effect of the invention” is provided. It has.
  Claim 5According to the characteristics, in addition to the right and left side clutches that can independently transmit and shut off the power to the right and left rear wheels, the right and left rear wheels can be braked independently. Thus, the turning performance of the passenger work vehicle can be improved by making the small turn to the right and left easier.
[0081]
  According to the feature of claim 6, the “effect of the invention” of the above-mentioned claim 1 to 5 is provided as in the case of any one of claims 1 to 5, and in addition to this “effect of the invention”. The following “effects of the invention” are provided.
  Claim 6According to the features, when equipped with a brake that can brake the front and rear wheels, even if the width of the middle part of the transmission case is narrow, the strength of the middle part of the transmission case is easily secured, so that the passenger type The overall strength of the work vehicle could be improved.
  Claim 6According to the characteristics, it is possible to avoid a situation in which the brake protrudes from the outer surface of the middle part of the transmission case. There is no such thing as a smaller orientation angle.
[0082]
  According to the feature of the seventh aspect, the “effect of the invention” of the above-mentioned claim 6 is provided in the same manner as the case of the sixth aspect. In addition to the “effect of the invention”, the following “effect of the invention” is provided. It has.
  Claim 7According to the feature, the brake can be configured to brake the sprocket gear that rotates around the uniaxial core, and a relatively general brake can be used, resulting in simplified structure and production cost. It became advantageous in terms of reduction of
[0083]
  According to the feature of the eighth aspect, the “effect of the invention” of the above-mentioned claim 7 is provided in the same manner as the case of the seventh aspect. In addition to the “effect of the invention”, the following “effect of the invention” is provided. It has.
  Claim 8According to the characteristics, it is possible to avoid the situation where the transmission chain is separated from the sprocket gear due to the vibration of the transmission chain, etc., and the braking by the brake does not reach the front wheel and the rear wheel, thereby improving the reliability of the brake operation. I was able to.
[0084]
[0085]
[Brief description of the drawings]
[Fig. 1] Overall side view of a riding rice transplanter
[Figure 2] Overall plan view of the riding rice transplanter
[Fig. 3] Side view of the vicinity of the transmission case, front wheel support case, transmission case, support frame, top link and lower link
FIG. 4 is a plan view of the vicinity of the transmission case, front wheel and front wheel support case, rear wheel and transmission case.
FIG. 5 is a side view of the vicinity of an engine and a hydrostatic continuously variable transmission.
FIG. 6 is a cross-sectional plan view of the front of the mission case and the vicinity of the front wheel support case
[Fig. 7] Transverse plan view of the front of the mission case
[Fig. 8] Cross-sectional plan view of the mission case change mechanism and planting clutch
FIG. 9 is a cross-sectional plan view of the mission case with the lid removed in the vicinity of the stock change mechanism.
FIG. 10 is a cross-sectional plan view of the mission case in the vicinity of the planting clutch when the planting clutch is operated to the cutoff side.
FIG. 11 is a cross-sectional plan view of the middle part of the transmission case and the vicinity of the front wheel support case.
FIG. 12 is a cross-sectional plan view of the mission case near the front wheel differential mechanism.
FIG. 13 is a cross-sectional plan view of the rear of the transmission case and the vicinity of the transmission case
FIG. 14 is a cross-sectional plan view near the rear of the mission case
FIG. 15 is a longitudinal side view of the transmission case near the transmission chain
FIG. 16 is a cross-sectional plan view of the vicinity of the mission case in the first alternative embodiment of the invention;
FIG. 17 is a transverse plan view of the vicinity of the front portion of the mission case in the first alternative embodiment of the invention;
FIG. 18 is a cross-sectional plan view of the vicinity of the mission case in the second alternative embodiment of the invention;
FIG. 19 is a cross-sectional plan view of the vicinity of the middle part of the mission case in the second alternative embodiment of the invention;
[Explanation of symbols]
  1 Mission case
  1d recess
  4 Front wheels
  6 Rear wheel
  16 engine
  24 input shaft
  26 Variable speed transmission shaft
  68 Front wheel drive shaft
  69 Front wheel differential mechanism
  71 Transmission gear
  79 Rear wheel transmission shaft
  82 Transmission chain
  86 Side clutch
  87 Side brake
  92a sprocket gear
  93 Guide members
  94 Brake
  P2 Horizontal axis

Claims (8)

An input shaft for transmitting engine power and a front wheel transmission shaft for transmitting power to the right and left front wheels are arranged in the left-right direction at the front of the transmission case, and the right and left of the front wheel transmission shaft The left and right front wheels are freely steerable at the end of the
A rear wheel transmission shaft that transmits power to the right and left rear wheels is arranged in the left-right direction at the rear part of the transmission case, and
A transmission chain that rotates around the axis in the left-right direction is disposed in the middle portion of the transmission case, a front wheel differential mechanism is disposed on the lateral side of the front portion of the transmission chain, and a front wheel differential mechanism at the front portion of the transmission chain Place the transmission gear on the side opposite to
The power of the input shaft is transmitted from the transmission gear to the front wheel transmission shaft through the front wheel differential mechanism, and the power of the input shaft is transmitted from the transmission gear to the rear wheel transmission shaft through the transmission chain. Passenger work vehicle. A transmission transmission shaft is arranged in the left-right direction on the lower side of the input shaft in the transmission case, and a transmission mechanism is configured between the input shaft and the transmission transmission shaft;
The riding type work vehicle according to claim 1, wherein power of the speed change transmission shaft is transmitted to a transmission gear . The right and left transmission cases are independently supported to swing up and down around the left and right axis around the rear of the transmission case, the right and left transmission cases are extended rearward, and the right and left transmission cases With the right and left rear wheels at the rear of the transmission case,
The riding work vehicle according to claim 1 or 2, wherein power of the rear wheel transmission shaft is transmitted to the right and left rear wheels via the right and left transmission cases. The right and left side clutches capable of independently transmitting and interrupting power to the right and left rear wheels are provided concentrically with the front wheel differential mechanism or on the rear wheel transmission shaft. The riding type work vehicle according to any one of the above . The riding type work vehicle according to claim 4, further comprising right and left side brakes capable of independently braking the right and left rear wheels in a state where power to the right and left rear wheels is cut off . The riding type work vehicle according to any one of claims 1 to 5, wherein a concave portion is formed on an outer surface of an intermediate portion of the transmission case, and a brake capable of braking a front wheel and a rear wheel is provided in the concave portion. . The riding type work vehicle according to claim 6, further comprising a sprocket gear that meshes with the transmission chain and rotates together, and the brake is configured to brake the sprocket gear . The riding type work vehicle according to claim 7, further comprising a guide member that prevents the transmission chain from being separated from the sprocket gear .

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