WO2014069627A1

WO2014069627A1 - Rice-planting machine

Info

Publication number: WO2014069627A1
Application number: PCT/JP2013/079699
Authority: WO
Inventors: 黒田　智之; 井上　誠
Original assignee: ヤンマー株式会社
Priority date: 2012-11-01
Filing date: 2013-11-01
Publication date: 2014-05-08
Also published as: KR20150079594A; CN104870232B; CN104870232A; JP5931698B2; KR102155388B1; JP2014092204A

Abstract

The present invention addresses the problem of reducing manufacturing cost of a group of models as a whole by facilitating common use of front axle cases and the like among rice-planting machine models having different treads between right and left wheels. This rice-planting machine is equipped with: a traveling machine body (1) on which an engine (8) and a transmission case (9) are mounted; and a rice-planting unit (4) that is attached in a liftable manner to the traveling machine body (1) via a linking mechanism (6). A pair of right and left front axle cases (10), which is located at an anterior part of the traveling machine body (1), is used to support front wheels (2). Rear axle cases (12), which are located at the posterior part of the traveling machine body (1), are used to support rear wheels (3). The upper ends of the respective front axle cases (10) are attached to a machine frame (7) of the traveling machine body (1). The front axle cases (10) are connected to the machine frame (7) in such a manner that the spacing therebetween can be adjusted to increase or decrease in the horizontal direction.

Description

Rice transplanter

The present invention relates to a rice transplanter that performs seedling planting work continuously by a planting part mounted on a traveling machine body.

A conventional rice transplanter includes a traveling machine body on which an engine and a transmission case are mounted, and a planting portion that is mounted on the traveling machine body so as to be movable up and down via a link mechanism, and a pair of left and right front axles at the front part of the traveling machine body. A front wheel is supported by a case, and a rear wheel is supported by a rear axle case at the rear of the traveling machine body (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 4-89474

By the way, there are models with different planting constants, such as 7-row planting and 8-row planting, for example. These have different treads (distance between wheels) between the left and right wheels. If the difference in the number of planting lines is large, there is a considerable difference in required power, aircraft size, etc., so the specifications of the mission case, front axle case, etc. must be different. On the other hand, if the difference in the number of planting strips is small, for example, for 7-row planting and 8-row planting, there is not much difference in required power etc., so it is possible to share specifications such as mission case and front axle case It is understood that there is.

However, in the past, separate mission cases and front axle cases were prepared for 7-row planting and 8-row planting, and each had its own dedicated specifications. Due to the large number of parts, there is a problem that the parts inventory of each model cannot be maintained sufficiently and productivity is lowered.

The present invention has been made in view of the above-described present situation, and in models where the tread between the left and right wheels is different, promote sharing of the front axle case and the like, and reduce the manufacturing cost of the entire model group. Is a technical issue.

The invention of claim 1 includes a traveling machine body on which an engine and a transmission case are mounted, and a planting portion that is mounted on the traveling machine body so as to be movable up and down via a link mechanism. In a rice transplanter in which a front wheel is supported by an axle case and a rear wheel is supported by a rear axle case at the rear part of the traveling machine body, an upper end side of each front axle case is attached to a body frame of the traveling machine body, and each front axle case is mounted. The arrangement interval is connected to the machine body frame so that the arrangement interval can be adjusted in the horizontal direction.

According to a second aspect of the present invention, in the rice transplanter according to the first aspect, the left and right front side frames of the body frame are provided with support brackets projecting to the left and right sides across the frame, The upper end side of each front axle case is detachably fastened to the outside.

According to a third aspect of the present invention, in the rice transplanter according to the second aspect, a spacer is interposed between the support bracket and the upper end side of each front axle case. The axle case is tilted in a three-dimensional direction that tilts backward and inwardly to the left and right.

According to the first aspect of the present invention, the vehicle includes a traveling machine body on which the engine and the transmission case are mounted, and a planting portion that is mounted on the traveling machine body so as to be movable up and down via a link mechanism. In a rice transplanter in which a front axle is supported by a front axle case and a rear axle is supported by a rear axle case at the rear of the traveling machine body, an upper end side of each front axle case is attached to a body frame of the traveling machine body, and each front axle case Are connected to the body frame so that the distance between them can be adjusted in the left-right direction, so that the tread between the left and right wheels (especially the front wheels) is shared by using both the front axle case and the body frame. The model can be configured. For this reason, it is not necessary to manufacture both the front axle cases and the body frame for each model, and the manufacturing cost can be suppressed as a whole model group. Since it is sufficient to stock the shared parts, it is possible to avoid the problem of productivity reduction due to the shortage of parts inventory between each model.

According to the second aspect of the present invention, the left and right front side frames of the airframe frame are provided with support brackets that extend to the left and right sides of the front frame, and the front axle cases are provided on the left and right inside or outside of the support bracket. Since the upper end side is detachably fastened, both front axle cases and the fuselage frame can be shared to form a model with different treads between left and right wheels (especially front wheels). The case can be configured as a strength member together with the fuselage frame, and the rigidity of the traveling aircraft can be improved with a simple configuration without increasing the thickness and strength of the fuselage frame or increasing the number of parts extremely. It can be a simple structure.

According to a third aspect of the present invention, a spacer is interposed between the support bracket and the upper end side of each front axle case, and the upper end surface of the spacer has the front axle case tilted rearward and in the left and right sides. Since it is inclined in the three-dimensional direction that is inclined in the direction, the mounting posture of each front axle case with respect to the body frame can be easily determined. For this reason, while improving the workability of assembling each front axle case, it is possible to easily ensure the steering stability of the traveling machine body.

It is a side view of the rice transplanter concerning an embodiment. It is a top view of the whole rice transplanter. It is a side view which shows the framework of a traveling machine body. It is a top view which shows the framework of a traveling machine body. It is a side view of the front part of a traveling machine body. (A) is a top view of a front part of a traveling machine body, and (B) is a plan view of a mission case. It is a perspective view which shows a mission case and a steering mechanism. It is a perspective view of the principal part. (A) is the perspective view which looked at the mission case from the front, (B) is the isolation | separation top view of a mission case. It is a bottom sectional view of a mission case. It is a sectional side view of the mission case in the open state. It is a perspective view which shows a transmission structure. It is a separate perspective view of the principal part. It is a vertical side view of the principal part. It is a side view of a mission case. It is a hydraulic circuit diagram. It is front explanatory drawing of a front axle case. It is front sectional drawing of a left front axle case. It is front sectional drawing of a right front axle case. It is an expanded front sectional view of the left gear case. It is a front view of a left front axle case. It is a side view of a left front axle case. It is a separate perspective view which shows the attachment structure of a left front axle case. It is a schematic plan view explaining the tread for 8-row planting. It is an expanded rear view which shows the attachment structure of the right front axle case for 7 row planting. It is a schematic plan view explaining the tread for 7 row planting. It is a skeleton figure which shows the power transmission system of a rice transplanter. It is a top sectional view showing a power transmission structure inside a mission case. It is a separate perspective view which shows the power transmission structure inside a mission case. (A) is the perspective view which looked at the inside of a mission case from back, (B) is the isolation | separation perspective view inside a mission case. It is a rear view of the power transmission system which showed the mission case with the virtual line and separated the intermediate plate. It is a perspective view which shows the structure of a mission case and a valve unit. It is a side view which shows the structure of a mission case and a valve unit. It is a perspective view which shows the structure of a mission case front part. It is a perspective view which shows the other structure of a mission case front part. It is a perspective view which shows the other structure of a mission case front part. It is a perspective view which shows the structure of a mission case rear part. It is a perspective view which shows the structure of a mission case and a valve unit. It is a front view of a valve unit. It is a rear view of a mission case. It is explanatory drawing which shows the structure of a hydraulic circuit. It is explanatory drawing which shows the structure which controls the traveling speed of a rice transplanter. It is a perspective view which shows the structure of a motor case. It is a partial cross section figure of the motor case of a rice transplanter, (A) is a figure at the time of transmission motor operation being possible, (b) is a figure at the time of transmission motor operation impossible. It is a left view of the left case of a rice transplanter.

Next, an embodiment in which the present invention is applied to a riding type rice transplanter will be described with reference to the drawings. In the following description, the words “front and rear” and “left and right” are used to specify the direction, which is based on the posture of the operator facing the forward direction.

(1). Overview of Rice Transplanter As shown in FIGS. 1 and 2, the rice transplanter of the embodiment is for 8-row planting, and a traveling machine body 1 that is supported by a left and right front wheel 2 and a left and right rear wheel 3 so as to freely travel, It has a seedling planting device 4 (planting part) for 8-row planting arranged behind the machine body 1. The front wheel 2 is attached to the traveling machine body 1 so as to be able to turn horizontally, and the rear wheel 3 is attached to the traveling machine body 1 so as to be unable to turn horizontally.

The seedling planting device 4 is connected to the traveling machine body 1 through a lifting link mechanism 6 so as to be lifted and lowered. The seedling planting device 4 is lifted and lowered by rotating the lifting link mechanism 6 with a hydraulic lifting cylinder 5. The seedling planting device 4 has a rotary planting mechanism, a seedling platform, a float, and the like, but details thereof are omitted because they are not directly related to the present invention. Although not shown, a fertilizer can be attached to the rear part of the traveling machine body 1.

As shown in FIGS. 3, 4, and 6, the traveling machine body 1 has a machine body frame 7, and an engine 8 is supported at the front of the machine body frame 7. A mission case 9 is disposed behind the engine 8, and the front wheels 2 are attached to left and right front axle cases 10 attached to the front part of the mission case 9. The rear wheel 3 is attached to a rear axle case 12, and the transmission case 9 and the rear axle case 12 are connected by a cylindrical connecting frame 11.

For example, as shown in FIG. 4, the body frame 7 includes left and right front side frames 7 a positioned at the front of the traveling body 1, left and right front frames 7 b connected to the front ends of the left and right front side frames 7 a, and left and right front sides. Left and right horizontal middle frames 7c connected to the rear ends of the side frames 7a, left and right rear side frames 7d extending rearward from the middle frames 7c, and left and right horizontal rear frames 7e fixed to the rear ends of the rear side frames 7d The rear frame 7e is supported by the rear axle case 12 via the rear column 7f. A left and right horizontally long stay 12a is fixed to the rear axle case 12, and a rear column 7f is fixed to the stay 12a.

The left and right front side frames 7 a have two front and rear U-shaped engine frames 13 fixed upward, and the engine frame 13 supports the engine 8. The engine 8 is placed horizontally so that the crankshaft is directed in the left-right direction. An auxiliary frame 14 having a U shape in plan view is fixed to the engine frame 13 on the front side. The auxiliary frame 14 is also connected to the front frame 7b. Since the engine frame 13 projects below the front side frame 7a, the engine 8 has a low center of gravity, and the crankshaft is positioned below the upper surface of the front side frame 7a.

The engine 8 is covered with a bonnet 15, and spare seedling stands 16 are disposed on the left and right sides of the bonnet 15. A driver's seat 17 is arranged behind the bonnet 15. The traveling machine body 1 has a vehicle body cover (step) 18 on which an operator is placed. Although a fuel tank is arranged below the driver's seat 17, details are omitted. A rotary steering handle 19 is disposed in front of the driver seat 17.

As shown in FIGS. 6 and 7, the front axle case 10 is attached to the front side frame 7a via a support bracket 100 and attached to the lower side of the vertical case 10a so as to be substantially horizontally rotatable. The front wheel 2 is attached to a front axle 103 (see FIGS. 17 to 19) provided on the gear case 10b. A knuckle arm 20 is fixed to the gear case 10b, and a tie rod 21 is connected to the knuckle arm 20 so as to be relatively rotatable. When the steering handle 19 is rotated, the left and right tie rods 21 move simultaneously via a power steering unit 35 described later, thereby causing the left and right front wheels 2 to turn horizontally in the same direction. As a result, the rice transplanter is steered.

For example, as shown in FIG. 7, a hydraulic continuously variable transmission 24 (HST) is mounted on the left side surface of the mission case 9. As shown in FIG. 16, the hydraulic continuously variable transmission 24 has a hydraulic pump 24a driven by the input shaft 25 and a hydraulic motor 24b driven by the hydraulic pump 24a. Power is transmitted to the input shaft 25 from the output shaft 26 of the engine 8 via the belt 27. A cooling fan 28 is fixed to the input shaft 25.

Needless to say, the output shaft 26 of the engine 8, the input shaft 25 of the hydraulic continuously variable transmission 24, and the motor output shaft 36 (see FIG. 10) are horizontally long and parallel. The hydraulic continuously variable transmission 24 is disposed such that the hydraulic pump 24a is positioned in front and the hydraulic motor 24b is positioned in the rear. The belt 27 is held constant in tension by a tension pulley 29.

The hydraulic continuously variable transmission 24 incorporates a swash plate for controlling the rate at which the power of the hydraulic pump 24a is transmitted to the hydraulic motor 24b. This swash plate is, for example, a control shaft 30 shown in FIG. It is driven by rotating. On the other hand, as shown in FIG. 4, a shift pedal 31 is provided in a portion of the control floor on the right side of the transmission case 9 in plan view. The rotation angle (depression amount) of the speed change pedal 31 is detected by a potentiometer.

Then, a control motor (not shown) is driven based on the detection signal of the potentiometer, and the control shaft 30 is rotated by a link mechanism (not shown) that is moved by the control motor. The power transmission ratio from the hydraulic pump 24a to the hydraulic motor 24b changes, and thereby the vehicle speed is adjusted steplessly according to the amount of depression of the shift pedal 31. However, since the control mode itself of the hydraulic continuously variable transmission 24 is not directly related to the present invention, a detailed description thereof will be omitted.

As shown in FIG. 3, the steering handle 19 rotates about an axis that is inclined with respect to the vertical line in a side view. Therefore, the steering handle 19 is fixed to the inclined upper handle shaft 32. The upper handle shaft 32 is fixed to the main handle shaft 33 in a vertical posture through a universal joint (not shown). The main handle shaft 33 is built in the handle post 34.

For example, as shown in FIG. 7, a hydraulic power steering unit 35 is attached to the front end portion of the transmission case 9, and the rotational torque of the main handle shaft 33 is amplified by the power steering unit 35 and transmitted to the tie rod 21. The

(2). Details of Structure Next, details of a part centering on the mission case 9 will be described with reference to FIG. For example, as shown in FIG. 6A, a tandem charge pump 37a and an auxiliary pump 37b driven by the input shaft 25 of the hydraulic continuously variable transmission 24 are arranged on the right side surface of the transmission case 9. Yes.

The input shaft 25 of the hydraulic continuously variable transmission 24 is always rotating as long as the engine 8 is operated, and therefore the charge pump 37a is always rotating. The hydraulic oil generated by the auxiliary pump 37 b is sent to the torque generator 39 of the power steering unit 35 through the first pipe 38. The hydraulic oil generated by the charge pump 37 a is sent to the oil supply port 41 of the hydraulic continuously variable transmission 24 through the second discharge pipe 40.

A valve unit 42 for controlling the above-described lifting cylinder 5 is fixed to the rear part of the transmission case 9, and the hydraulic oil discharged from the torque generator 39 of the power steering unit 35 flows through the third pipe 43. Sent to unit 42.

For example, as shown in FIG. 9 (B), the mission case 9 is composed of two members, a main body portion 9a having a deep depth and a lid portion 9b covering the main body portion 9a. Yes. A steering support portion 46 that protrudes forward is formed in a substantially lower half portion of the front end of the main body 9 a in the transmission case 9, and the power steering unit 35 is fixed to the steering support portion 46.

The steering support portion 46 protrudes from the front surface of the main body portion 9a constituting the mission case 9, and thus has a front end surface and left and right side surfaces. For example, as shown in FIG. 7, a forward projecting portion 47 is formed at the lower end of the steering support portion 46. A bracket 48 is connected to the forward projecting portion 47 with a bolt 49, and the bracket 48 is fixed to the engine 8. is doing.

A receiving port 52 through which surplus oil or leaked oil collected in the case of the hydraulic continuously variable transmission 24 flows is provided on the right side surface of the steering support portion 46, and discharge that leads into the case of the hydraulic continuously variable transmission 24 is provided. The port 53 and the receiving port 52 are connected by a metal drain pipe 54. Note that the drain pipe 54 may be one in which an air cooler or the like is interposed in the middle thereof.

The mission case 9 also serves as an oil tank, and the hydraulic oil that has flowed into the steering support portion 46 returns to the inside of the mission case 9 (details will be described later). Needless to say, the drain pipe 54 is connected to the hydraulic continuously variable transmission 24 and the steering support 46 by a joint 55.

For example, as shown in FIG. 9, an oil filter 56 is provided below the charge pump 37 a on the right side surface of the mission case 9, and oil accumulated in the mission case 9 passes through the oil filter 56 to the charge pump 37 a. Inflow.

Next, the internal structure of the mission case 9 will be briefly described with reference to FIGS. A planetary gear mechanism 57 is provided inside the mission case 9, and the output of the hydraulic continuously variable transmission 24 is combined by the planetary gear mechanism 57 and taken out to the combined output shaft 58.

As shown in FIG. 11, below the combined output shaft 58, the counter shaft 59 and the travel transmission shaft 60 are disposed in a state of being displaced forward and backward, and further below the counter shaft 59 and the travel transmission shaft 60. In this part, the front wheel drive shaft 61 and the PTO transmission shaft 62 are arranged in a state of being displaced forward and backward, and the rear wheel drive shaft 63 is arranged in a part below the PTO transmission shaft 62.

A plurality of fixed gears 64 for shifting are fixed to the composite output shaft 58 so as not to slide, and a sliding gear 65 is attached to the traveling transmission shaft 60 by spline fitting. Then, by shifting the shifter shaft 66 and sliding the sliding gear 65 to change the meshing with the fixed gear 64 or to bring it into a neutral state, the rice transplanter operates in a planting mode (low speed forward), a road traveling mode ( There are five modes: high speed advance), seedling mode (neutral), neutral mode, and reverse mode.

The sliding of the shifter shaft 66 is performed by rotating a shift lever (not shown). The composite output shaft 58 is provided with a main clutch 68. The travel transmission shaft 60 is provided with a brake mechanism 69 such as a multi-plate type. Although the details are omitted because it is not directly related to the present invention, the main clutch 68 is automatically engaged when the shift pedal 31 (see FIGS. 2 and 4) is depressed, and when the shift pedal 31 is fully returned. The brake mechanism 69 works lightly. Further, the brake mechanism 69 can be strongly applied by stepping on the brake pedal 70 (see FIG. 3).

As shown in FIG. 10, the front wheel drive shaft 61 is separated into two left and right at the inner bottom of the mission case 9, and power is transmitted to the front axle case 10 through the respective shafts. The left and right front wheel drive shafts 61 are connected via a differential gear mechanism 71 (a differential lock device 72 that eliminates the differential relationship between the left and right front wheel drive shafts 61 is also provided).

The rotation of the travel transmission shaft 60 is transmitted from the output gear at the left end of the page in FIG. 10 to the differential gear mechanism 71 and also transmitted to the rear wheel drive shaft 63 via the three flat gears 74 as shown in FIG. The rotation of the rear wheel drive shaft 63 is transmitted to the rear output shaft 77 through a pair of bevel gears 76. Of the three flat gears 74, an intermediate flat gear is supported on the PTO transmission shaft 62 at the left end of the drawing sheet of FIG.

The rotation of the composite output shaft 58 is transmitted to the PTO transmission shaft 62 through three spur gears 75 including the output gear fixed to the right end of the paper surface in FIG. It is transmitted from the shaft 62 to the PTO output shaft 79 through a pair of bevel gears 78. An intermediate gear of the three spur gears 75 is connected to the brake mechanism 69 on the travel transmission shaft 60 and is supported idle.

Although not shown in FIGS. 10 to 12, the PTO output shaft 79 is input to the inter-strain transmission, and the power is transmitted from there to the seedling planting device 4 via the PTO shaft. When the fertilizer is provided, power is transmitted from the inter-strain transmission to the fertilizer.

As shown in FIG. 10, an intermediate plate 80 for holding the shafts 58 to 63 is arranged inside the main body 9a constituting the mission case 9. The intermediate plate 80 is fixed to the main body 9a with bolts. Due to the presence of the intermediate plate 80, each axis can be held in a stable state.

Next, the power steering device will be described. As shown in FIGS. 13 and 14, the power steering unit 35 includes the torque generator (hydraulic motor) 39 described above and a speed reduction mechanism that decelerates the rotation of the output shaft 82 of the torque generator 39. The generator 39 is fastened to the upper surface of the steering support 46 with bolts, and the speed reduction mechanism is disposed in a concave space (that is, a large opening upward) formed on the upper surface of the steering support 46.

As shown in FIG. 13, the speed reduction mechanism of the power steering unit 35 includes a sun gear shaft 83a into which an output shaft (not shown) of a torque generator 39 is inserted and spline-fitted, and a first sun gear engraved at the lower end of the sun gear shaft 83a. 83, a first carrier 86 and a second sun gear 85, which support the three first planetary gears 84 and the first planetary gears 84 driven by the first sun gear 83, and have the second sun gear 85 fixed at the center of rotation. And three second planetary gears 87 meshed from the outside, and a second carrier 88 supporting the second planetary gears 87.

As shown in FIG. 14, a steering shaft 89 is integrally provided at the rotation center of the second carrier 88, and the steering shaft 89 is rotatably held by the steering support portion 46 by a bearing 90. That is, the steering support portion 46 is a steering gear box of the power steering unit 35. The steering shaft 89 protrudes downward from the bottom of the steering support 46, and the pitman arm 91 is fixed to the downward protrusion, and the tie rod 21 is connected to the tip of the pitman arm 91 so as to be relatively rotatable. .

The output shaft 82 of the torque generator 39 is transmitted to the three first planetary gears 84 via the first sun gear 83, and the three first planetary gears 84 circulate around the axis of the output shaft in a decelerated state. As a result, the first carrier 86 rotates. When the first carrier 86 rotates, the second planetary gear 87 orbits around the second sun gear 85 in a decelerated state, whereby the second carrier 88 further decelerates and rotates. As a result, the rotation of the output shaft 82 is decelerated in two stages and transmitted to the steering shaft 89. A cylindrical body 92 is arranged on the inner peripheral wall of the empty space of the steering support portion 46, and an internal gear 93 that meshes with the first and second

planetary gears

84 and 87 from the outside on the inner peripheral surface of the cylindrical body 92. Is formed.

As shown in phantom lines in FIG. 14, the receiving port 52 opens toward the empty space of the steering support portion 46, and the steering support portion 46 has a drain hole 94 that opens toward the transmission case 9. Forming. Accordingly, surplus oil and leak oil carried out from the case of the hydraulic continuously variable transmission 24 come into contact with the inner surface of the void of the steering support portion 46, gears, etc., and then return to the oil sump inside the transmission case 9. The drain hole 94 is positioned below the oil level OL of the oil stored in the mission case 9, and therefore the drain hole 94 is always immersed in the oil.

And since members such as gears constituting the drain pipe 54, the steering support 46, or the speed reduction mechanism of the power steering unit 35 have higher thermal conductivity than oil, the oil is cooled in the process of returning to the inside of the transmission case 9. Is done. Therefore, even if the rice transplanter is used for a long time, it is possible to suppress a decrease in efficiency of the hydraulic continuously variable transmission 24.

For example, as shown in FIGS. 9A and 15, a large number of ribs 96 are formed on the left and right side surfaces of the steering support portion 46 so as to protrude outward in the left and right directions (that is, in a direction perpendicular to the opening surface of the main body portion 9a). ing. The ribs 96 intersect vertically and horizontally in a side view. When the power steering unit 35 is operated, a large load is applied to the steering support 46, but high strength is maintained by the presence of the group of ribs 96, and the rib 96 exhibits the function of a cooling fin. The oil cooling effect by can also be improved.

Now, both ends of the drain pipe 54 are fixed to the hydraulic continuously variable transmission 24 and the steering support portion 46 by joints 55. Since the drain pipe 54 is fitted into the joint 55, the length of the drain pipe 54 is fixed. If the length is short, a twist may occur between the end portion of the drain pipe 54 and the joint 55 unless bending is performed with high accuracy.

On the other hand, in this embodiment, since the drain pipe 54 is connected to the right side surface far from the hydraulic continuously variable transmission 24 among the left and right side surfaces of the steering support portion 46, the drain pipe 54 is connected compared to the case where it is connected to the left side surface. When the pipe 54 is connected to the joint 55 of the receiving port, the steering support portion 46 is wound up, and the length of the drain pipe 54 is inevitably long. Therefore, the drain pipe 54 is highly accurate. Even without bending, variations in processing accuracy can be absorbed by slight bending deformation. Further, if the length of the drain pipe 54 is long, the air cooling effect is increased accordingly, and the cooling effect is also increased.

The engine 8 of this embodiment is a water-cooled type, and thus has a radiator cooled by a fan. However, the drain pipe 54 can be extended to the vicinity of the fan of the radiator to be forcibly cooled. It is.

(3). Next, the internal structure of the front axle case 10 will be described with reference to FIGS. 17 to 19 in addition to FIGS. As described above, the front axle case 10 includes the vertical case 10a fixed to the front side frame 7a via the support bracket 100, and the gear case 10b attached to the lower side of the vertical case 10a so as to be substantially horizontally rotatable. The left and right side surfaces of the mission case 9 and the vertical case 10a of each front axle case 10 are connected by a horizontally long output case 101. In the embodiment, the vertical case 10 a is integrally formed on the left and right outer sides of the output case 101. Accordingly, the output case 101 itself also constitutes an element of the vertical case 10a and thus the front axle case 10.

A downward opening cylindrical case cover 102 is fixed to the upper side of the vertical case 10a. Front wheel drive shafts 61 projecting left and right outward from the left and right side surfaces of the mission case 9 are inserted into the output cases 101. A front axle 103 protruding outward in the left and right directions is rotatably supported on the gear case 10b. The front wheel 2 is attached to the front axle 103.

¡The knuckle arm 20 is bolted to the upper outer side of the gear case 10b. The left and right knuckle arms 20 are connected to the front end side of the pitman arm 91 disposed below the steering support portion 46 of the transmission case 9 via the tie rod 21. The left and right front wheels 2 are turned around the kingpin type drive shaft 104 inserted into the vertical case 10b in proportion to the steering angle (rotational operation angle) of the steering handle 19.

18 and 19, the front wheel drive shaft 61 is connected to the upper side of the kingpin type drive shaft 104 through the

bevel gears

105 and 106 so as to transmit power. The lower side of the kingpin type drive shaft 104 is connected to the base end side of the front axle 103 through

bevel gears

107 and 108 so that power can be transmitted. The transmission and differential output of the transmission case 9 are transmitted from the differential gear mechanism 71 to the left and right front wheel drive shafts 61, and rotational power is transmitted to the front wheels 2 from each front wheel drive shaft 61 via the kingpin type drive shaft 104 and the front axle 103. introduce.

The knuckle arm 20 is provided with a vertical arm portion 109 extending upward in parallel with the kingpin type drive shaft 104. A cylindrical sliding / rotating support portion 110 is integrally formed on the upper end side of the vertical arm portion 109. The sliding / rotating support portion 110 of the knuckle arm 20 is fitted on the case cover 102 so as to slide and rotate. The knuckle arm 20 is supported by the gear case 10b and the case cover 102 in a doubly supported beam shape.

The lower side of the kingpin type drive shaft 104 is rotatably supported in the middle of the gear case 10b via a bearing. On the upper side of the kingpin type drive shaft 104, the lower surface side of the piston type holder 111 is rotatably supported via a bearing. Inside the case cover 102, large, medium and small diameter compression coil spring type suspension springs 112 and a piston type holder 111 are accommodated in a state where the lower end side of the suspension spring 112 is in contact with the upper surface side of the piston type holder 111. Due to the elastic restoring force of the suspension spring 112, the front wheel 2 is always urged downward via the kingpin type drive shaft 104 and the gear case 10b. That is, the ground pressure of the front wheel 2 is maintained by the action of the suspension spring 112.

The suspension spring 112 is maximally compressed by the body weight of the traveling machine body 1, and the suspension spring 112 is brought into close contact with the left and right front wheels 2 and the left and right rear wheels 3 (front and rear four wheels) in contact with each other. ) Is kept constant. In a stepped traveling state in which the three wheels of the left and right rear wheels 3 and either the left or right front wheel 2 are in contact with each other, the suspension spring 112 is extended to lower the ungrounded front wheel 2 to thereby reduce the ground pressure of the left and right front wheels 2. To prevent slipping.

As shown in FIG. 20, the lower side of each gear case 10b is opened outward in the left-right direction. A case lid 113 that closes the opening is bolted to the lower side of each gear case 10b. A front axle 103 is rotatably supported on the case lid 113. The front axle 103 penetrates the case lid 113 and protrudes left and right outward. A flange portion 114 extending in the radial direction is provided at the left and right protruding end portions of the front axle 103. A hub body 120 that is a rotation center portion of the front wheel 2 is bolted to the flange portion 114 of the front axle 103.

An annular recess 115 surrounding the front axle 103 is formed on the left and right side surfaces of the case lid 113. On the outer peripheral side of the annular recess 115, an outward lip 116 is provided to project left and right outward. An oil seal 117 is accommodated in the annular recess 115. An annular groove portion 118 surrounding the front axle 103 is formed on the left and right inner side surfaces of the flange portion 114. An annular groove 118 on the flange 114 side and an annular recess 115 (oil seal 117) on the case lid 113 side are inserted into the annular groove 118 on the flange 114 side so as to insert the outward lip 116 on the case lid 113 side. Make them confront. A labyrinth gap 119 is formed between the annular groove 118 on the flange 114 side and the outward lip 116 on the case lid 113 side. The presence of the labyrinth gap 119 prevents foreign matters such as muddy water and sawdust from entering the gear case 10b, thereby extending the life of the oil seal 117 and improving the sealing performance of the gear case 10b.

(4). Sharing parts between different models Next, sharing parts between different types of rice transplanters will be described with reference to FIGS. Here, FIGS. 21 to 24 are explanatory diagrams corresponding to the eight-row planting, and FIGS. 25 and 26 are explanatory diagrams corresponding to the seven-row planting. Now, although the rice transplanter of the embodiment has been described as for eight-row planting, the traveling machine body 1 of the embodiment has a tread between the left and right front wheels 2 and a tread between the left and right rear wheels 3. By changing, it can respond to 7-row planting and 5-row planting. In the rice transplanter of the embodiment, the tread between the left and right front wheels 2 and the tread between the left and right rear wheels 3 are common for 8-row planting and 6-row planting, and for 5-row planting and 7-row planting. I have to. As shown in FIGS. 24 and 26, the treads for 8 and 6 planting are set wider than the treads for 7 and 5 planting. In any case of five-row to eight-row planting, the tread between the left and right rear wheels 3 changes the mounting position of the rear wheel 3 with respect to the rear axle 121 protruding outward from the rear axle case 12 in the left-right direction. Will be changed.

The tread between the left and right front wheels 2 is changed depending on how each front axle case 10 is attached. As shown in FIGS. 21 to 24, in the case of 8-row planting, a mounting spacer 122 is mounted on the uppermost portion (head) of the case cover 102 that accommodates the suspension spring 114 from above with a spacer fixing bolt 123 (FIG. 18). And fastening (see FIG. 19). A recess 124 for accommodating the head of the spacer fixing bolt 123 is formed on the upper surface side of the mounting spacer 122. The shaft portion of the spacer fixing bolt 123 is inserted into the insertion hole 125 formed in the recess 124 so as to penetrate vertically, and the shaft portion of the spacer fixing bolt 123 is screwed and fixed to the head of the case cover 102. Bolt holes 126 are formed in the four corners on the upper surface side of the mounting spacer 122.

On the other hand, the left and right front side frames 7a of the body frame 7 are provided with support brackets 100 that protrude from the left and right sides of the frame. In the embodiment, the left and right center portions of the support bracket 100 are fixed to the lower surface side of the middle portion of the front side frame 7a by welding or the like. Insertion holes 128 corresponding to the bolt holes 126 of the mounting spacer 122 are formed in the left and right wing portions 127 of the support bracket 100. A total of eight insertion holes 128 are formed in each of four left and right wing parts 127. For 8-row planting, the upper surface side of the mounting spacer 122 is superimposed on the lower surface side of the left and right outer wings 127, and the mounting bolts 129 inserted into the four insertion holes 128 are screwed into the bolt holes 126 of the mounting spacer 122. Thus, the upper end side of the front axle case 10 is detachably connected to the left and right outer sides of the support bracket 100. Even in the case of six-row planting, the upper end side of the front axle case 10 is fastened to the wing 127 on the left and right outer sides of the support bracket 100 via the mounting spacer 122.

Thus, when the upper end side of each front axle case 10 is detachably connected to the left and right outer sides of the support bracket 100 provided on the left and right front side frames 7a, each front axle case 10 is connected to the body frame 7 (front side frame 7a). ) And strength members. Therefore, the rigidity of the traveling machine body 1 can be improved with a simple configuration without increasing the thickness and strength of the machine body frame 7 and increasing the number of parts extremely, and a robust structure can be achieved.

When the front axle case 10 (kingpin type drive shaft 104) is in a vertical posture, the upper end surface of the mounting spacer 122 is inclined in a three-dimensional direction diagonally forward and downward outward. Therefore, the front axle case 10 (king pin type drive shaft 104) is in the rear in a state where the upper end side of the front axle case 10 is fastened to the left and right outer wings 127 of the support bracket 100 via the mounting spacer 122. The posture is inclined and inclined inward and leftward and rightward. That is, the mounting posture of each front axle case 10 with respect to the body frame 7 can be easily determined by the inclined state of the upper end surface of the mounting spacer 122. In other words, the front axle case 10 is simply tightened to the wings 127 on the left and right outer sides of the support bracket 100 via the mounting spacer 122 at the upper end side of the front axle case 10 so that each front axle case 10 has a kingpin inclination angle as originally designed. And can be easily set to casters. Therefore, the operational stability of the traveling machine body 1 can be easily ensured while improving the assembling workability of each front axle case 10.

In addition, in the case of 8-row planting, the weight of the seedling planting device 4 is heavy for 8-row planting, and the connecting frame 11 and the left and right rear side frames 7d are extended (for 5-7 row planting). Therefore, it is necessary to improve the torsional rigidity of the traveling machine body 1. In this regard, in the embodiment, the mounting boss 130 is provided so as to project upward on the upper surface side of the output case 101 of each front axle case 10, and the upper and lower reinforced connecting plates 131 are disposed on the wings 127 on the left and right inner sides of the support bracket 100. The side is fastened with a bolt 132 and a nut 133, while the lower side of the reinforcing connecting plate 131 is fastened with a bolt 134 to the mounting boss 130.

For this reason, the front axle case 10 includes the body frame 7 (front side frame 7a) or the transmission at the upper end side of the case cover 102, the mounting boss portion 130 in the middle of the output case 101, and the base end side of the output case 101. It is connected to the case 9. Accordingly, the strength of the front axle case 10, the body frame 7 and the transmission case 9 can be improved, and the reaction force from the ground via the front wheels 2 is also effective by the front axle case 10, the body frame 7 and the transmission case 9. This contributes to further improvement in rigidity of the traveling machine body 1. By the way, in the rice transplanter for planting 5-7 strips, the connecting frame 11 and the left and right rear side frames 7d are the same (the wheel bases have the same length).

FIG. 25 and FIG. 26 are explanatory diagrams corresponding to 7-row planting. In this case, the length of the output case 101 of each front axle case 100 is made shorter than that for 6 and 8 planting. Then, the upper surface side of the mounting spacer 122 is superimposed on the lower surface side of the left and right inner wings 127 of the support bracket 100, and the mounting bolts 129 inserted into the four insertion holes 128 are screwed into the bolt holes 126 of the mounting spacer 122. Thus, the upper end side of the front axle case 10 is detachably connected to the left and right inner sides of the support bracket 100. Even in the case of five-row planting, the upper end side of the front axle case 10 is fastened to the wing 127 on the left and right inner sides of the support bracket 100 via the mounting spacer 122. In other words, in the rice transplanter of the embodiment, the front axle cases 10 are connected to the body frame 7 (the left and right front side frames 7a) so that the mutual arrangement interval can be adjusted in the horizontal direction. In this case, the arrangement intervals of the front axle cases 10 can be changed to the two narrow specifications (the arrangement intervals of the two narrow specifications can be selected).

Therefore, both front axle cases 10 and the fuselage frame 7 can be shared to form a model with different treads between the left and right wheels 2 and 3 (particularly the front wheels 2). In the embodiment, the front axle case 10 and the body frame 7 can be shared from a rice planter for five-row planting to a rice planter for eight-row planting. It is not necessary to manufacture both front axle cases 10 and the body frame 7 for each model, and the manufacturing cost can be suppressed as a whole model group. Since it is only necessary to stock the shared parts, it is possible to avoid the problem of the productivity drop due to the shortage of parts inventory between each model.

(5). First Summary As can be understood from the above description, the traveling machine body 1 on which the engine 8 and the transmission case 9 are mounted, and the planting portion 4 that is mounted on the traveling machine body 1 via the link mechanism 6 so as to be movable up and down. A rice transplanter in which a front wheel 2 is supported by a pair of left and right front axle cases 10 at the front part of the traveling machine body 1 and a rear axle 3 is supported by a rear axle case 12 at the rear part of the traveling machine body 1. Since the upper end side of each front axle case 10 is attached to the airframe frame 7 and the front axle case 10 is connected to the airframe frame 7 so that the distance between each other can be adjusted in the horizontal direction. By sharing the front axle case 10 and the body frame 7, different models of tread between the left and right wheels 2 and 3 (particularly the front wheel 2) can be configured. For this reason, it is not necessary to manufacture both the front axle case 10 and the body frame 7 for each model, and the manufacturing cost can be suppressed as a whole model group. Since it is sufficient to stock the shared parts, it is possible to avoid the problem of productivity reduction due to the shortage of parts inventory between each model.

Further, the left and right front side frames 7a of the body frame 7 are provided with support brackets 100 projecting on both the left and right sides of the frame, and the upper end of each front axle case 10 is provided on the left and right inner side or the outer side of the support bracket 100. Since the side is detachably fastened, the front axle case 10 and the body frame 7 can be used in common to form different models of tread between the left and right wheels 2 and 3 (particularly the front wheel 2). However, both the front axle cases 10 can be configured as strength members together with the airframe frame 7, and the airframe frame 7 can be configured with a simple structure without increasing the thickness and strength of the airframe frame 7 or extremely increasing the number of parts. The rigidity of the traveling machine body 1 can be improved and a robust structure can be achieved.

Further, a spacer 122 is interposed between the support bracket 100 and the upper end side of each front axle case 10, and the upper end surface of the spacer 122 tilts the front axle case 10 backward and inwardly in the left and right directions. Therefore, the mounting posture of the front axle case 10 with respect to the body frame 7 can be easily determined. For this reason, while improving the workability of assembling each front axle case 10, the steering stability of the traveling machine body 1 can be easily ensured.

(6). Detailed structure of the power transmission system of the rice transplanter and the inside of the transmission case Next, the detailed structure of the power transmission system of the rice transplanter and the inside of the transmission case 9 will be described with reference to FIGS. As shown in FIGS. 27 and 28, the power transmitted from the engine 8 to the input shaft 25 is shifted by the hydraulic continuously variable transmission 24 and the planetary gear mechanism 57. The hydraulic continuously variable transmission 24 includes a variable displacement hydraulic pump 24a and a fixed displacement hydraulic motor 24b. The power input from the input shaft 24 drives the hydraulic pump 24a, feeds hydraulic oil from the hydraulic pump 24a to the hydraulic motor 24b, and rotates the motor output shaft 36 of the hydraulic motor 24b.

The pump output shaft 214 of the hydraulic pump 24a and the charging output shaft 216 are coaxially connected to the input shaft 25. In this case, a transmission gear 215 is fixed to the pump output shaft 214 of the hydraulic pump 24a. One end of a charging output shaft 216 arranged coaxially with the pump output shaft 214 is inserted into and fixed to the transmission gear 215, and from the other end, the charge pump 37a of the hydraulic continuously variable transmission 24 and auxiliary Power is transmitted to the pump 37b.

The motor output shaft 36 of the hydraulic motor 24b supports a sun gear 221 and a carrier 222 that can rotate freely with respect to the boss portion of the sun gear 221 and has a tooth portion on the outer periphery. The outer peripheral teeth of the carrier 222 are engaged with the transmission gear 215. Three planetary gears 223 are rotatably provided around the sun gear 221. A ring gear 224 is meshed with the outside of the three planetary gears 223. Thus, the planetary gear mechanism 57 is formed by the sun gear 221, the carrier 222, the three planetary gears 223, and the ring gear 224.

By changing the angle of the movable swash plate of the hydraulic pump 24a by operating the speed change pedal 31, hydraulic oil corresponding to the angle is sent from the hydraulic pump 24a. The power (rotational speed) of the motor output shaft 36 of the hydraulic motor 24b is changed according to the amount of oil fed from the hydraulic pump 24a, and the sun gear 221 rotates at a speed corresponding to this power. On the other hand, when the pump output shaft 214 of the hydraulic pump 24a rotates, the transmission gear 215 and the carrier 222 rotate, and the planetary gear 223 rotates.

Thereafter, the power of the sun gear 221 and the power of the planetary gear 223 are combined by the planetary gear mechanism 57 and output from the combined output shaft 58 inserted into the ring gear 224. That is, the combined output shaft 58 rotates or stops at a speed corresponding to the angle of the movable swash plate of the hydraulic pump 24a.

Further, a main clutch 68 is interposed between the ring gear 224 and the composite output shaft 58. The main clutch 68 switches whether power can be transmitted from the planetary gear mechanism 57 to the combined output shaft 58. In the main clutch 68, the ring gear 224 and the composite output shaft 58 are connected or disconnected by sliding the clutch shifter. In this way, power transmission from the ring gear 224 to the composite output shaft 58 is interrupted.

The power transmitted to the combined output shaft 58 is transmitted to the left and right front wheels 2 and the rear wheels 3 through a gear-type traveling system transmission path. The gear-type travel system transmission path is formed on the composite output shaft 58, the counter shaft 59, the travel transmission shaft 60, the main transmission mechanism 240, the front wheel drive shaft 61, the rear wheel drive shaft 63 as the travel transmission shaft, and the rear output shaft 77. Is done. Further, the power transmitted to the composite output shaft 58 is transmitted to the seedling planting device 4 through a gear-type PTO transmission path. The gear-type PTO transmission path is formed on the composite output shaft 58, the travel transmission shaft 60, the PTO transmission shaft 62, and the PTO output shaft 79.

28, a counter shaft 59, a travel transmission shaft 60, a PTO transmission shaft 62, and a rear wheel drive shaft 63 are arranged in parallel with the combined output shaft 58. A midway portion of the composite output shaft 58 is supported by an intermediate plate 80 provided in the main body portion 9a via a bearing, and a right end side thereof is supported by the lid portion 9b via the bearing. The left end sides of the counter shaft 59, the travel transmission shaft 60 and the PTO transmission shaft 62 are supported by the intermediate plate 80 via bearings, and the right end sides thereof are supported by the lid portion 9b via the bearings. The left end side of the rear wheel drive shaft 63 is supported by the main body 9a via a bearing, and the right end side thereof is supported by the intermediate plate 80 via the bearing.

27 and 28, a main transmission mechanism 240 is provided between the combined output shaft 58, the counter shaft 59, and the traveling transmission shaft 60 in the gear-type traveling system transmission path. The main transmission mechanism 240 shifts the power from the combined output shaft 58 to a plurality of stages and outputs it to the traveling transmission shaft 60. The main transmission mechanism 240 includes a reverse side input gear 241, a forward gear 242 and a moving gear 243 that constitute the fixed gear 64, a reverse side output gear 244, a reverse gear 245, and a slide gear 65.

The reverse-side input gear 241 and the forward gear 242 are integrally configured so that the reverse-side input gear 241 is on the left side and the forward gear 242 is on the right side. The reverse input gear 241 and the forward gear 242 are fixed in the middle of the composite output shaft 58. The moving gear 243 is disposed on the right side of the forward gear 242 and is fixed to the combined output shaft 58. The reverse output gear 244 is fixed to the left end side of the counter shaft 59 and meshes with the reverse input gear 241 and the reverse output gear 244 to constantly transmit the power of the combined output shaft 58 to the counter shaft 59. The reverse gear 245 is fixed to the right end side of the counter shaft 59.

The sliding gear 65 is spline-fitted to the middle part of the travel transmission shaft 60 and is provided so as not to be relatively rotatable and slidable. The sliding gear 65 is formed with a small diameter gear 246a and a large diameter gear 246b. The sliding gear 65 slides with respect to the traveling transmission shaft 60 by operation of a transmission lever (not shown), and the small-diameter gear 246a meshes with the forward gear 242 so that the main transmission mechanism 240 is moved forward and the large diameter is increased. When the gear 246b is engaged with the moving gear 243, the main transmission mechanism 240 is "moved", and when the large diameter gear 246b is engaged with the reverse gear 245, the main transmission mechanism 240 is "reverse", and the small diameter gear 246a and the large diameter gear 246b. Is configured to switch the main transmission mechanism 240 to “neutral” when the gear does not mesh with any gear. Thus, the power from the combined output shaft 58 is shifted and output to the traveling transmission shaft 60.

A brake mechanism 69 is provided on the right end side of the travel transmission shaft 60. The brake mechanism 69 brakes the rotation of the travel transmission shaft 60. In the brake mechanism 69, by operating the brake pedal 70 (see FIG. 3), the cylindrical piston 251 is pressed to bring the plurality of friction plates 252 provided on the travel transmission shaft 60 and the lid portion 9b into contact with each other. As a result, the travel transmission shaft 60 is braked.

27, a front transmission gear 261 is fixed to the left end side of the travel transmission shaft 60, and the front transmission gear 261 meshes with an input gear of the differential gear mechanism 71. The power of the travel transmission shaft 60 is transmitted to the left and right front wheel drive shafts 61 via the differential gear mechanism 71. The power transmitted to the left and right front wheel drive shafts 61 is transmitted to the left and right front wheels 2 via the front axle case 10 to rotate these front wheels 2. The differential gear mechanism 71 can be locked by a differential lock device 72.

As shown in FIGS. 27 and 28, a rear first transmission gear 271 is fixed in the middle of the travel transmission shaft 60. The rear first transmission gear 271 meshes with the rear second transmission gear 272 serving as a counter gear. The rear second transmission gear 272 is loosely fitted to the left end side of the PTO transmission shaft 62. Specifically, a rolling bearing 272a such as a ball bearing is interposed between the rear second transmission gear 272 and the PTO transmission shaft 62 so as to be relatively rotatable. Instead of the rolling bearing 272a, a sliding bearing such as a bush may be used.

The rear second transmission gear 272 meshes with a rear third transmission gear 273 fixed on the right end side of the rear wheel drive shaft 63. The left end side of the rear wheel drive shaft 63 is connected to one end side of the rear output shaft 77 through a pair of bevel gears 76. The power of the travel transmission shaft 60 is transmitted to the rear output shaft 77 via the rear wheel drive shaft 63. The power transmitted to the rear output shaft 77 is transmitted to the left and right rear wheels 3 via the respective rear axle cases 12 to rotate these rear wheels 3. The combination of the rear transmission gears 271 to 273 constitutes the aforementioned flat gear 74.

In the gear-type PTO transmission path, a PTO first transmission gear 281 is fixed on the right end side of the composite output shaft 58. The PTO first transmission gear 281 meshes with the PTO second transmission gear 282 serving as a counter gear. The PTO second transmission gear 282 is loosely fitted to the right end side of the travel transmission shaft 60. Specifically, a sliding bearing 282a such as a bush is interposed between the PTO second transmission gear 282 and the travel transmission shaft 60 so as to be relatively rotatable. It is also possible to use a rolling bearing such as a ball bearing instead of the sliding bearing 282a.

The PTO second transmission gear 282 meshes with the PTO third transmission gear 283 fixed in the middle of the PTO transmission shaft 62. The right end side of the PTO transmission shaft 62 is connected to one end side of the PTO output shaft 79 through a pair of bevel gears 78. The power of the combined output shaft 58 is transmitted to the PTO output shaft 79 via the PTO transmission shaft 62. A combination of the PTO transmission gears 281 to 283 constitutes the aforementioned flat gear 75.

The power transmitted to the PTO output shaft 79 is transmitted to the seedling transplanting device 4 after being shifted by an acceleration / deceleration gear or a transmission mechanism built in the inter-strain transmission case 50 (see FIG. 27). As a result, the lateral feed mechanism of the seedling planting device 4 is activated to slide the seedling platform in the left-right direction, or the rotary type planting mechanism is activated, so that the seedling taken out from the seedling mat on the seedling platform is placed in the field. Plant it.

Thus, by supporting the rear second transmission gear 272 of the gear-type traveling system transmission path by the PTO transmission shaft 62 of the gear-type PTO system transmission path, the number of shafts that support the gears of the gear-type traveling system transmission path can be reduced. Can be reduced. Similarly, by supporting the PTO second transmission gear 282 of the gear type PTO system transmission path by the traveling speed change shaft 60 of the gear type travel system transmission path, the number of shafts supporting the gears of the gear type PTO system transmission path is reduced. it can. Therefore, the internal structure of the mission case 9 can be simplified, contributing to cost reduction and improving the assemblability of the mission case 9.

Furthermore, since the composite output shaft 58 is arranged on the front side inside the mission case 9 and the PTO transmission shaft 62 and the rear wheel drive shaft 63 are arranged on the rear side inside the mission case 9, the composite output shaft 58 and the PTO transmission shaft 62 and The structure up to the rear wheel drive shaft 63 can be simplified, and the front-rear width of the mission case 9 can be shortened.

As shown in FIG. 28, the rotation direction of the composite output shaft 58 is clockwise as viewed from the hydraulic continuously variable transmission 24 side regardless of the working state. During the planting operation, the rotational direction of the travel transmission shaft 60 is counterclockwise when viewed from the hydraulic continuously variable transmission 24 side, and the rotational direction of the rear second transmission gear 272 is indicated by a two-dot chain line arrow X. When viewed from the hydraulic continuously variable transmission 24 side, it is clockwise. Further, during the planting operation, the rotation direction of the PTO transmission shaft 62 is clockwise as viewed from the hydraulic continuously variable transmission 24 side as indicated by the solid arrow Y.

In other words, during the planting operation, the rear second transmission gear 272 and the PTO transmission shaft 62 are configured to have the same rotational direction, so there is a difference in the rotational speed between the rear second transmission gear 272 and the PTO transmission shaft 62. It becomes difficult to occur. Therefore, the rolling bearing 272a is less likely to be worn and the life can be extended. Similarly, during the planting operation, the rotational directions of the PTO second transmission gear 282 and the travel transmission shaft 60 are configured to be the same. Therefore, the rotational speeds of the PTO second transmission gear 282 and the travel transmission shaft 60 are also different. It becomes difficult to occur. Therefore, the sliding bearing 282a is not easily worn, and the life can be extended.

As described above, the mission case 9 includes the main body portion 9a having a deep depth and the lid portion 9b having a shallow depth. As shown in FIGS. 27 to 30, an intermediate plate 80 extending in the front-rear direction is disposed inside the main body 9a. The intermediate plate 80 is detachably fixed at a substantially intermediate position in the left-right width direction of the main body 9a. The composite output shaft 58, the counter shaft 59, the traveling speed change shaft 60, the five shafts of the PTO transmission shaft 62 and the rear wheel drive shaft 63 and one end of the differential gear mechanism 71 can be rotated by the intermediate plate 80 via bearings. Supported by

Although the charging output shaft 216 is not supported by the intermediate plate 80, the charging output shaft 216 can be supported by the intermediate plate 80. Specific arrangements of the shaft group and gear group and the shaft support structure are shown in FIGS. This point will be described below.

As shown in FIGS. 29 and 30, a steering support portion 46 is provided at the lower front end of the mission case 9. In the embodiment, the hydraulic oil used in the hydraulic continuously variable transmission 24 is returned to the inside of the transmission case 9 via the steering support portion 46 (to cool the hydraulic oil).

The rotation axis of each axis extends in the vehicle width direction (left-right direction). As a whole, they are arranged side by side in the direction from the front part to the rear lower part of the mission case 9. Specifically, the charging output shaft 216 is disposed at the top and at the front, the composite output shaft 58 is disposed behind the charge output shaft 216, and the counter shaft 59 and the travel transmission shaft 60 are disposed below the composite output shaft 58. Place them apart from each other. Further, the front wheel drive shaft 61 and the PTO transmission shaft 62 are disposed below the traveling transmission shaft 60 in a state where they are separated from each other. The rear wheel drive shaft 63 is disposed at the lowest and rearmost position.

The intermediate plate 80 is plate-shaped and extends long along the direction in which the shaft groups are arranged. In the side view, it has an appearance that extends in an oblique direction. A large space is provided between the outer peripheral surface of the intermediate plate 80 and the inner peripheral surface of the main body portion 9 a in the transmission case 9. The hydraulic oil can freely move in the space between the main body 9a and the intermediate plate 80.

As can be understood from FIG. 31, the intermediate plate 80 is disposed in a state of being deeply inserted into the main body portion 9a (approximately in the middle position in the axial direction and the left-right width direction). As shown in FIG. 29, a plurality of boss portions 290 for fixing the intermediate plate 80 are formed in the main body portion 9a. The peripheral portion of the intermediate plate 80 is fastened to each boss portion 290 with a bolt 291. As the boss portion 290 of the embodiment, there are a stepped portion projecting from the bottom inner surface and wall inner surface of the main body portion 9a to the inside of the case, and a boss portion 290 protruding inward from the inner surface of the side wall of the main body portion 9a to the inside of the case. is doing.

The left end side of the charging output shaft 216 is connected to the pump output shaft 214 of the hydraulic pump 24a via the transmission gear 215. The right end side of the charging output shaft 216 is rotatably supported on the lid portion 9b via a bearing. The left and right central portions of the composite output shaft 58 are rotatably supported on the intermediate plate 80 via bearings. The right end portion of the composite output shaft 58 is rotatably supported on the lid portion 9b via a bearing. The ring gear 224 is rotatably supported on the left end side of the composite output shaft 58, while the carrier 222 with the planetary gear 223 is rotatably supported and the sun gear 221 is fixed to the motor output shaft 36 of the hydraulic motor 24b. .

Therefore, the composite output shaft 58 is rotatably supported by the main body 9a via the planetary gear mechanism 57 and is also rotatably supported by the intermediate plate 80 and the lid 9b. Further, since the main clutch 68 and the planetary gear mechanism 57 provided on the composite output shaft 58 are accommodated within a short span between the main body 9a and the intermediate plate 80, the support strength of the composite output shaft 58 is increased. Is extremely high, and the support stability of the main clutch 68 and the planetary gear mechanism 57 is also excellent. Since the planetary gear mechanism 57 and the main clutch 68 are arranged close to each other, the transmission case 9 can be made compact. Further, since the posture of the composite output shaft 58 is firmly held by the main body portion 9a and the intermediate plate 80, the lid portion 9b can be accurately aligned. Therefore, the assembly of the mission case 9 is easy and the maintenance is easy.

The traveling speed change shaft 60 and the counter shaft 59 are rotatably supported on the intermediate plate 80 and the lid portion 9b via bearings. Since the travel transmission shaft 60 and the counter shaft 59 can be shortened in length as compared with the case where they are supported by the main body portion 9a and the lid portion 9b, the strength against bending can be increased accordingly and the posture stability is also excellent. Accordingly, durability can be improved and assembly and maintenance can be facilitated. The space formed between the main body portion 9a and the intermediate plate 80 by shortening the traveling transmission shaft 60 and the counter shaft 59 can be accommodated in the planetary gear mechanism 57 and the differential gear mechanism 71 that require a space in the radial direction. Available.

The brake mechanism 69 is attached inside the lid portion 9b. Since the main body 9a of the transmission case 9 is connected to the rear axle case 12 via the connecting frame 11, the main body 9a cannot be easily removed, but the lid 9b can be removed relatively easily. Since the brake mechanism 69 is overused, the necessity for maintenance and replacement is high, but in the embodiment, the brake mechanism 69 is attached to the lid portion 9b that can be easily removed, so that the maintenance and replacement of the brake mechanism 69 can be easily performed. Although not shown in the figure, the operation tool of the brake mechanism 69 is provided on the lid portion 9b.

In the embodiment, the main body portion 9a of the transmission case 9 functions as a strength member (frame member) of the traveling machine body 1 by being connected to the rear axle case 12 via the connection frame 11. By adopting such a configuration, an advantage of simplifying the entire structure of the mission case 9 can be obtained. While securing such advantages, the workability of maintenance and repair of the brake mechanism 69 is improved.

The sliding gear 65 provided on the traveling transmission shaft 60 is slid by, for example, a transmission shifter 292 shown in FIG. The shift shifter 292 is attached to the left and right horizontally long shifter shaft 66. The shifter shaft 66 is partially exposed on the left side of the main body 9a. The shifter shaft 66 is slidably fitted between the intermediate plate 80 and the lid portion 9b. The shifter shaft 66 is formed with a plurality of (five) grooves 294 for holding the position thereof, and a presser (for example, a ball) biased by a spring is fitted into the groove 294 so that the rice transplanter , Planting mode (low speed advance), road running mode (high speed forward), seedling mode (neutral), neutral mode, and reverse mode are maintained.

The intermediate plate 80 is provided with an upward hole 295 into which a holder (not shown) for holding a spring and a presser is inserted. Thus, since the shifter shaft 66 can be temporarily supported together with the main transmission mechanism 240 on the intermediate plate 80 separable from the main body 9a, the assembly of the transmission case 9 can be performed very easily.

The differential gear mechanism 71 is rotatably supported on the main body 9a and the intermediate plate 80 via a bearing. The main body portion 9a is provided with an inward protruding portion 9c protruding toward the lid portion 9b. The left end side of the differential gear mechanism 71 is rotatably supported by the end portion of the inward projecting portion 9c. Thus, since the differential gear mechanism 71 rotatably supports both ends, the differential gear mechanism 71 maintains extremely high stability with a short width. In the embodiment, the diff lock device 72 is arranged inside the inward protruding portion 9c provided in the main body portion 9a. For this reason, the differential lock device 72 can be made compact.

The PTO transmission shaft 62 is rotatably supported on the intermediate plate 80 and the lid portion 9b via a bearing. Since the length of the PTO transmission shaft 62 can be shortened compared with the case where it is supported by the main body 9a, the strength and stability can be improved. The rear wheel drive shaft 63 is rotatably supported by the main body 9a and the intermediate plate 80. Since the length of the rear wheel drive shaft 63 is very short, an extremely high strength and stability can be ensured.

Now, in order to attach the PTO transmission shaft 62 and the PTO output shaft 79 to the lid portion 9b, there is an empty space 297 having an L-shaped cross section and an opening inwardly in the case and a rearward opening 298 in the rear of the case. Yes. The PTO output shaft 79 is rotatably supported in the space 297 by two front and rear bearings, and is prevented from coming off by a snap ring 299. The driven bevel gear 78 provided on the PTO output shaft 79 is set to a size that can be removed from the rear opening 298 of the space 297. The bevel gear 78 on the PTO transmission shaft 62 side is spline-fitted to the distal end side of the PTO transmission shaft 62 and positioned in the space 297 so that it can be removed from the rear opening 298 of the space 297. is doing. Therefore, only the bevel gear 78 can be removed from the PTO transmission shaft 62, and the two bevel gears 78 can be removed by removing the snap ring 299 and removing the PTO output shaft 79 without removing the lid portion 9b itself. Can be exchanged.

The PTO output shaft 79 rotates in proportion to the traveling speed. Therefore, the seedling planting interval (between plants) is basically adjusted by the strain adjusting mechanism built in the strain shifting case 50 (see FIG. 27). Is done. As a manufacturer, there is a case where it is desired to optionally prepare a specification that slightly changes between stocks relative to reference stocks according to the characteristics of crops and regions. That is, there is a case where a fine adjustment function between stocks may be prepared as an option. In this regard, in the embodiment, the PTO output shaft 79 can be easily removed and the two bevel gears 78 can be replaced, so that it is possible to easily cope with a demand for fine adjustment between stocks.

The lid 9a can be removed after draining the oil inside the mission case 9. In this case, the right front wheel 2 is also removed. When the lid portion 9a is removed, the traveling machine body 1 is in a three-wheel support state, but the traveling machine body 1 can be stably held by being supported by some member. Therefore, even if the whole is not lifted and disassembled by a crane or the like at a maintenance shop, the maintenance and repair of the inside of the traveling mission case 9 can be performed by removing the lid portion 9b even in the user's warehouse or work site, for example. . For this reason, the labor required for maintenance and repair can be remarkably reduced.

The assembly of the mission case 9 is performed as follows, for example. A composite output shaft 58 through which the intermediate plate 80 passes is inserted and connected to the planetary gear mechanism 57 mounted on the left side in the main body 9a, and a bevel gear 76 on the rear wheel drive shaft 63 side is disposed in the main body 9a. The rear wheel drive shaft 63 through which the intermediate plate 80 is inserted is inserted and connected to the bevel gear 76. In accordance with these, the left front wheel drive shaft 61, the differential gear mechanism 71, and the differential lock device 72 are attached to the left side in the main body 9a. Then, the intermediate plate 80 is fastened with the bolt 291 to the main body 9a. Then, the counter shaft 59, the travel transmission shaft 60, and the PTO transmission shaft 62 are attached to the intermediate plate 80, and a gear group and a brake mechanism 69 are fitted on these

shafts

58, 59, 60, 62. The charging output shaft 216 is attached to the main body 9a either before or after the intermediate plate 80 is attached. Then, the lid portion 9b is put on the main body portion 9a and bolted. Thereafter, the pair of bevel gears 78 and the PTO output shaft 79 are attached in the space 297 of the lid portion 9b.

(7). Second Summary As can be understood from the above description, the power from the engine 8 is shifted by the hydraulic continuously variable transmission 24, and is output from the output shaft 58 of the hydraulic continuously variable transmission 24 via the travel transmission shaft 60. In the rice transplanter configured to transmit to the PTO transmission shaft 62 and the traveling transmission shaft 63, the output shaft 58, the traveling transmission shaft 60, the PTO transmission shaft 62, and the traveling transmission shaft 63 are placed in the transmission case 8. The transmission case 8 includes a main body portion 9a having a deep depth and a shallow lid portion 9b covering the main body portion 9a, and the output shaft 58, the traveling speed change shaft 60, the PTO transmission shaft 62, and the traveling transmission shaft 63. Is disposed in a posture intersecting with the opening surfaces of the main body 9a and the lid 9b, and the output shaft 58, the travel speed change shaft 60, the PTO transmission shaft 62, and the transmission shaft 62 are disposed in the main body 9a of the transmission case 9. Since the intermediate plate 80 that rotatably supports the travel transmission shaft 63 is detachably fixed, the

shafts

58, 60, 62, and 63 in the transmission case 9 are in a state in which the lid portion 9b is removed. However, since it is supported by the main body 9a and the intermediate plate 80, it is held in a state where it is accurately positioned at an accurate position. Therefore, the assembly of the mission case 9 can be performed accurately and efficiently. Since the intermediate plate 80 functions as a reinforcing member, it contributes to increasing the strength of the mission case 9.

It is also effective for improving workability during maintenance and parts replacement. That is, in the present invention, the main body 9a can be held in a predetermined posture on the main body 9a having a deep depth by having the main body 9a deep and having the intermediate plate 80. While attaching to the traveling machine body 1, only the lid portion 9b is removed, and an operation such as shaft replacement can be performed. That is, the frequency of removing the mission case 9 can be remarkably reduced, and the workability of maintenance and repair can be improved.

A gear-type traveling system transmission path and a gear-type PTO system transmission path are formed on the output shaft 58, the traveling transmission shaft 60, and the PTO transmission shaft 62, and the PTO transmission in the gear-type PTO system transmission path is formed. A travel transmission gear 272 on the shaft 62 is loosely fitted to the PTO transmission shaft 62, and a PTO transmission gear 282 on the travel transmission shaft 60 in the gear-type travel system transmission path is connected to the travel transmission shaft 60. Therefore, the number of power transmission shafts accommodated in the transmission case 9 can be reduced as much as possible, the number of parts can be reduced, and the cost can be reduced.

Further, since the rotation direction of the PTO transmission shaft 62 and the traveling transmission gear 272 is the same during work, the difference in rotational speed between the PTO transmission shaft 62 and the traveling transmission gear 272 is determined during the work. There is little possibility that it will occur, and the wear of the bearing located between the PTO transmission shaft 62 and the traveling transmission gear 272 can be suppressed, which contributes to a longer life.

In addition, since the hydraulic power steering unit 35 is disposed in the front part of the transmission case 9, and the power steering unit 35 is attached to the front part of the main body 9a in the transmission case 9, It is not necessary to remove the power steering unit 35 for maintenance and repair inside the mission case, and this is particularly effective for improving workability of maintenance and repair.

(8). Next, other configurations that can be employed in the embodiment will be described with reference to FIGS. 32 to 45. FIG. For example, as shown in FIG. 35, an oil cooler 301 can be interposed in the middle of the drain pipe 54. The oil cooler 301 is formed by being appropriately curved a plurality of times so that the hydraulic piping has an area approximately the same as the area of the vent opening opened in the radiator 302 in a side view, and is disposed on the side of the radiator 302. It is attached. More specifically, the radiator 302 is disposed so as to face the fan provided on the right side of the engine 8 and attached to the right side of the radiator 302. For this reason, the oil cooler 301 is located on the ventilation path of the fan together with the radiator 302, and the cooling efficiency of the hydraulic oil flowing through the drain pipe 54 and the hydraulic continuously variable transmission 24 can be improved.

Also, as shown in FIG. 36, it is possible to provide a plurality of heat dissipating fins 303 in the oil cooler 301. In this case, since the cooling area of the oil cooler 301 can be increased by the radiation fins 303, the cooling efficiency of the hydraulic oil flowing through the drain pipe 54 is further improved. If the radiator 302 and the radiator 302 cooling fan are arranged on the left side of the engine 8, the drain pipe 54 that connects the drain pipe 54 and the oil cooler 301 can be configured to be short.

That is, in the embodiment, in order to cool the hydraulic system of the hydraulic continuously variable transmission 24 including the drain pipe 54, the fan 28 (see FIG. 3) is disposed on the left side of the hydraulic continuously variable transmission 24. Is mounted on the input shaft 25 of the hydraulic continuously variable transmission 28. However, according to the oil cooler 301 shown in FIG. 35 and FIG. 36, the fan 28 is not required, so the distance between the left and right front axle cases 10 is shortened. Thus, the front wheel 2 can be configured compactly.

32 and 34, the charge pump 37a pumps hydraulic oil to the hydraulic continuously variable transmission 24, and is attached to the upper right part of the front portion of the transmission case 9. As shown in FIG. 41, the charge pump 37a is driven by the power of the engine 8, sucks the hydraulic oil in the transmission case 9 from the hydraulic pipe 304, converts the hydraulic oil into hydraulic oil, and hydraulically supplies the hydraulic oil from the second discharge pipe 40. The pressure is fed to the hydraulic pump 24 a of the continuously variable transmission 24.

The charge pump 37a is connected to the hydraulic continuously variable transmission 24 through the second discharge pipe 40. As shown in FIG. 34, one end of the second discharge pipe 40 is connected to a discharge port 305 provided at the rear of the charge pump 37a. The second discharge pipe 40 bypasses the front part of the power steering unit 35 on the front part of the transmission case 9 and the other end side of the second discharge pipe 40 is provided at the front part of the hydraulic continuously variable transmission 24. Concatenated with Thus, the second discharge pipe 40 is less likely to be splashed with mud and the like repelled from below, and the hydraulic oil is also easily cooled.

32 and 34, the auxiliary pump 37b pumps hydraulic fluid to various actuators. The auxiliary pump 37b is disposed on the right side of the charge pump 37a and is attached to the mission case 9 together with the charge pump 37a. As shown in FIG. 41, the auxiliary pump 37b is driven by the power of the engine 8, sucks the hydraulic oil in the transmission case 9 from the hydraulic pipe 304, converts the hydraulic oil into pressure oil, and starts the power steering unit from the first pipe 38. Pump to 35.

The auxiliary pump 37b is connected to the power steering unit 35 via the first pipe 38. As shown in FIG. 34, the one end side of the 1st pipe | tube 38 is connected to the discharge port 306 provided in the rear part of the auxiliary pump 37b. The first pipe 38 bypasses the right front part of the transmission case 9 and connects the other end of the first pipe 38 to an oil supply port 307 provided on the right side of the power steering unit 35. In this way, the first pipe 38 is less likely to be splashed by mud and the like repelled from below, and the hydraulic oil is also easily cooled.

Further, an oil filter 58 is provided below the charge pump 37a and the auxiliary pump 37b. A hydraulic pipe 304 is provided on the upstream side of the oil filter 58, the charge pump 37a, and the auxiliary pump 37b. The hydraulic oil in the mission case 9 is supplied from the hydraulic pipe 304 to the charge pump 37a and the auxiliary pump 37b via the oil filter 58.

32 to 34, the power steering unit 35 assists the operation of the steering handle 19, and is attached to the front center upper surface of the mission case 9. As shown in FIG. 41, the power steering unit 35 includes a torque generator 39. By operating the steering handle 19, the torque generator 39 is operated to control the flow of hydraulic oil from the first pipe 38. 19 operations are assisted. As a result, the directions of the left and right front wheels 2 can be easily operated with a small operating force.

The power steering unit 35 (torque generator 39) is connected to the valve unit 42 via the third pipe 43. As shown in FIGS. 32 and 34, a connection port 308 is provided on the upper right side of the power steering unit 35, and one end side of the third pipe 43 is connected to the connection port 308. The third pipe 43 bypasses the right side portion of the mission case 9 and is connected to a connection port 309 provided on the upper right side of the valve unit 42. The power steering unit 35 supplies the pressure oil from the first pipe 38 to the valve unit 42 via the third pipe 43.

As shown in FIG. 2, the valve unit 42 is attached to the rear part of the mission case 9. Specifically, it is attached to the upper rear surface of the mission case 9 and at the center of the left and right. As shown in FIG. 38, the valve unit 42 is detachably attached to the mission case 9 with four bolts 310, and is configured to have good maintainability and ease of assembly. Further, as shown in FIG. 33, the valve unit 42 is disposed above the extension portion 9d and the connecting frame 11 extending rearward from the rear lower side of the transmission case 9 to the valve unit 42 during traveling. Configure to prevent mud.

The valve unit 42 is disposed below the vehicle body cover 18. The valve unit 42 can be easily maintained by removing the vehicle body cover 18 or opening a part of the vehicle body cover 18. Furthermore, as shown in FIG. 32, the heavy valve unit 42 is arranged at the left and right center position of the mission case 9, that is, at the left and right center position of the rice transplanter, and the right and left weight balance of the rice transplanter 1 is good. It is comprised so that it may become.

The valve unit 42 is connected to the elevating cylinder 5 via a hydraulic pipe 311. A connection port 312 is provided on the upper left and right central sides of the valve unit 42, and one end side of the hydraulic pipe 311 is connected to the connection port 312. The other end side of the connection port 312 is connected to a connection port 5 e provided on the upper left side of the elevating cylinder 5. Thus, since the valve unit 42 is attached to the rear part of the transmission case 9, the length of the hydraulic pipe 311 connected to the elevating cylinder 5 located behind the transmission case 9 can be shortened. The valve unit 42 controls the flow of pressure oil to the elevating cylinder 5 and operates the elevating cylinder 5 to raise and lower the seedling planting device 4.

41, the valve unit 42 includes a control valve 42f that is an electromagnetic valve (proportional valve) that controls the flow of pressure oil to the elevating cylinder 5. By operating the control valve 42f with a solenoid to control the flow of hydraulic oil supplied from the third pipe 43, the amount of hydraulic oil flowing into the oil chamber 5d of the lift cylinder 5 is adjusted and the seedling planting device 4 is lifted and lowered. Let The valve unit 42 includes a stop valve 42g. The stop valve 42g is interposed between the control valve 42f and the elevating cylinder 5. The seedling planting device 4 can be stopped at an arbitrary height by operating the stop valve 42g.

The elevating cylinder 5 is of a hydraulic type, and includes a piston rod 5a, a piston 5b fixed to the base end of the piston rod 5a, a cylinder tube 5c in which the piston 5b is housed, and the like. The inside of the cylinder tube 5c is separated into two chambers on the rod chamber side and the head chamber side by the piston 5b. The oil chamber on the rod chamber side becomes the oil chamber 5d on the ascending side of the lifting cylinder 5, and the oil chamber on the head chamber side becomes the oil chamber 5f on the descending side. An accumulator 313 for accumulating hydraulic pressure is inserted through the oil chamber 5d.

The oil chamber 5d communicates with the connection port 5e, and connects the connection port 5e to the hydraulic pipe 311. The elevating cylinder 5 is operable by pressure oil from the hydraulic pipe 311. The oil chamber 5f communicates with the connection port 5g, and connects the connection port 5g to the hydraulic pipe 314. The leaked oil that has leaked into the oil chamber 5f is returned to the transmission case 9 via the hydraulic pipe 314.

FIG. 37 is a rear perspective view showing a state where the valve unit 42 is detached from the mission case 9. The hydraulic piping 314 from the elevating cylinder 5 is along the connecting frame 11 by a binding band 314 a fixed to the right side surface of the connecting frame 11. The front end side of the hydraulic pipe 314 is connected to a discharge port 315 provided on the rear lower side of the transmission case 9. The discharge port 315 is positioned below the oil level of the hydraulic oil in the mission case 9.

Further, the valve unit 42 communicates with the mission case 9. Specifically, in the valve unit 42, two communication holes 42e are formed on the contact surface 42d that contacts the transmission case 9 (see FIG. 39). In the transmission case 9, two communication holes 9f corresponding to the communication holes 42e on the valve unit 42 side are formed on the contact surface 9e that contacts the contact surface 42d on the valve unit 42 side. The hydraulic fluid is returned from the valve unit 42 to the transmission case 9 by communicating the

communication holes

42e and 9f. The hydraulic oil is returned below the oil level of the hydraulic oil in the mission case 9. For this reason, the hydraulic piping which connects the valve unit 42 and the transmission case 9 becomes unnecessary. A plurality of relief valves 42h are interposed between one communication hole 42e in the valve unit 42 and the control valve 42f (see FIG. 41).

41, the valve unit 42 is connected to the horizontal control valve unit 317 via a hydraulic pipe 316. Specifically, a discharge port 318 is provided on the upper left side of the valve unit 42, and one end side of the hydraulic pipe 316 is connected to the discharge port 318. The other end of the hydraulic pipe 316 is connected to a connection port provided at the top of the horizontal control valve unit 317. The valve unit 42 includes a flow divider 42i for distributing hydraulic oil. The hydraulic oil distributed by the flow divider 42 i is supplied from the hydraulic pipe 316 to the horizontal control valve unit 317.

Although illustration is omitted, the horizontal control valve unit 317 is disposed behind the elevating link mechanism 6. As shown in FIG. 41, the horizontal control valve unit 317 includes a horizontal control solenoid valve 317a. By switching the solenoid valve 317a for horizontal control, the horizontal cylinder 319 provided integrally with the horizontal control valve unit 317 is expanded and contracted to control the planting portion 15 to be horizontal. The planting unit 15 is provided with an inclination sensor. When the planting unit 15 is tilted from the horizontal position, the solenoid valve 317a for horizontal control is switched and the horizontal cylinder 319 is extended or shortened, and the planting unit 15 is moved. Control to keep it level.

The horizontal control valve unit 317 is connected to the mission case 9 via the hydraulic pipe 320. More specifically, a drain port is provided at the top of the horizontal control valve unit 317, and one end side of the hydraulic pipe 320 is connected to the drain port. The other end of the hydraulic pipe 320 is connected to a connection port 321 (see FIG. 38) provided on the rear upper side of the transmission case 9. The horizontal control valve unit 317 is configured to return the hydraulic oil of the horizontal cylinder 319 from the hydraulic pipe 320 to the transmission case 9. The

hydraulic pipes

311, 316 and 320 are configured so that the hydraulic system becomes compact by bundling them with a binding band or the like.

With this configuration, the hydraulic continuously variable transmission 24 serving as a heat source is separated from the valve unit 42. Similarly, the power steering unit 35 is also arranged at an appropriate interval from the hydraulic continuously variable transmission 24 serving as a heat source. For this reason, the temperature rise of the hydraulic fluid which flows into the valve unit 42 and the power steering unit 35 can be suppressed. Therefore, the amount of hydraulic oil can be reduced and the risk of deterioration can be reduced, and the number of hydraulic oil replacements can be reduced. In addition, cooling of the hydraulic system can be reduced and costs can be reduced.

As described above, in the rice transplanter of the embodiment, the auxiliary pump 37b serving as a hydraulic pump that is driven by the power of the engine 8, the transmission case 9 that contains the hydraulic oil supplied to the auxiliary pump 37b, and the transmission case 9 The elevating cylinder 5 that is disposed rearward and raises and lowers the planting portion 15 by feeding pressure oil from the auxiliary pump 37b, and the control valve 42f that controls the flow of hydraulic oil to the elevating cylinder 5 are provided. In the rice transplanter including the valve unit 42, the valve unit 42 is attached to the rear part of the transmission case 9, so that the hydraulic piping connecting the valve unit 42 and the transmission case 9, and the valve unit 42 and the lifting cylinder 5 are The length of the hydraulic piping to be connected can be shortened. Therefore, the space occupied by the hydraulic piping can be reduced, and the hydraulic system becomes compact.

Further, since the communication hole 42e for returning the hydraulic oil is formed in the contact surface 42d that contacts the transmission case 9 in the valve unit 42, piping connecting the valve unit 42 and the transmission case 9 becomes unnecessary, and the hydraulic pressure is reduced. The system becomes even more compact.

Further, since the valve unit 42 is disposed below the vehicle body cover 18, the valve unit 42 can be easily maintained by removing the vehicle body cover 18 or partially opening the vehicle body cover 18.

Further, since the hydraulic continuously variable transmission 24 for shifting the power of the engine 8 is provided, and the hydraulic continuously variable transmission 24 is disposed at the front portion of the transmission case 9, the hydraulic pressure in which the valve unit 42 serves as a heat source. It will separate from the type continuously variable transmission 24, and the temperature rise of the hydraulic fluid flowing through the valve unit 42 can be suppressed. Accordingly, the amount of hydraulic oil can be reduced, the hydraulic oil can be deteriorated, and the number of hydraulic oil replacements can be reduced.

Further, an oil cooler 301 for cooling the hydraulic continuously variable transmission 24 is disposed on a side portion of the radiator 302. Thereby, the cooling efficiency of the hydraulic continuously variable transmission 24 can be improved.

Hereinafter, the configuration related to the control for changing the traveling speed of the rice transplanter will be described with reference to FIG. The shift pedal 31 is an operation tool for changing the traveling speed of the rice transplanter, and more specifically, an operation tool for changing a rotation angle of a transmission motor 391 described later. The operation amount of the shift pedal 31 is configured to be detectable by the shift pedal potentiometer 31a. The shift pedal potentiometer 31 a is connected to the control device 390 and transmits a detection signal to the control device 390.

The transmission motor 391 is for changing the rotational speed of the engine 8, changing the transmission ratio of the hydraulic continuously variable transmission 24, switching the connection of the main clutch 68, and switching the operation of the brake mechanism 69. The output shaft of the transmission motor 391 includes a speed control device 392 that adjusts the rotational speed of the engine 8 via a link mechanism, a transmission arm 393 that changes the angle of the movable swash plate of the hydraulic continuously variable transmission 24, and a main clutch 68. The clutch arm 394 that turns on and off and the brake arm 395 that brakes the brake mechanism 69 are connected. The transmission motor 391 is connected to the control device 390 and is driven and controlled based on a signal transmitted from the control device 390.

The control device 390 controls the transmission motor 391. The control device 390 is provided at an arbitrary position of the traveling machine body 1. Specifically, the control device 390 may be configured such that a CPU, ROM, RAM, HDD, or the like is connected by a bus, or may be configured by a one-chip LSI or the like. The control device 390 stores various programs and maps for controlling the operation of the transmission motor 391 in advance. The control device 390 drives and controls the transmission motor 391 based on the detected value of the shift pedal potentiometer 31a and the various programs and maps.

In the rice transplanter configured as described above, it becomes impossible to run if the speed change motor 391 is damaged due to flooding or the like and stops moving. Therefore, in the rice transplanter of the embodiment, the rotating shaft constituting a part of the link mechanism that connects the output shaft of the speed change motor 391 and the speed governor 392 and the like is manually rotated not only in the speed change motor 391 but also in an emergency. It is configured as possible. Below, the structure is demonstrated using FIGS. 43-45.

43, the transmission motor 391 is covered with a motor case 400. Although not shown, the motor case 400 is accommodated in the bonnet 15. The motor case 400 is formed of a left case 400L on the left side and a right case 400R on the right side, and a manual operation shaft 401 serving as the rotation shaft projects leftward from the left case 400L. As shown in FIG. 44, a manual operation shaft 401 is fitted with a cylindrical tube shaft 402 so as to be relatively rotatable so that the manual operation shaft 401 and the tube shaft 402 are double shafts. It has become. A nut 404 is fixed to the left end portion of the cylindrical shaft 402, and a drilling hole 402 a is formed coaxially with the nut 404. At the left end portion of the manual operation shaft 401, an engagement portion 401a is formed coaxially with the drill hole 402a of the cylindrical shaft 402.

As shown in FIG. 44 (A), at the normal time when the speed change motor 391 is operable, the bolt 403 is inserted into the nut 404 and the hole 402a, and the tip of the bolt 403 is connected to the manual operation shaft 401. It abuts on the engaging portion 401a. That is, the manual operation shaft 401 and the cylinder shaft 402 are connected to each other so as to be integrally rotatable.

A fan-shaped sector gear 405 is fixed in the middle of the cylindrical shaft 402, and a tooth portion provided on the outer periphery of the sector gear 405 meshes with a gear provided on the output shaft of the transmission motor 391. One end of an L-shaped transmission gear 406 is fixed to the right end of the manual operation shaft 401, and the front end of the rod 407 is fixed at the bent portion of the transmission gear 406. The rear end of the rod 407 is connected to the transmission arm 393, the clutch arm 394, and the brake arm 395 (see FIG. 42).

The fan-shaped gear 405 is provided with a cam groove extending in the circumferential direction, and a transmission shaft slidably fitted in the cam groove is connected to one end side of the connecting member. The other end of the connecting member is connected to one end of an operation arm 408 shown in FIG. The other end side of the operation arm 408 is connected to a speed governor 392 of the engine 8 via a wire 409 or the like.

44B, when the speed change motor 391 cannot be operated, the bolt 403 is loosened from the nut 404 to release the connection between the manual operation shaft 401 and the cylindrical shaft 402. Then, after attaching the auxiliary arm 410 to the left end side 401b of the manual operation shaft 401, the auxiliary arm 410 is operated to operate the transmission arm 393, the clutch arm 394, and the brake arm 395. At this time, since the auxiliary arm 410 can be operated with the left hand and the steering handle 19 can be operated with the right hand, the escape operation from the farm field or the like can be performed while sitting in the driver's seat 17.

Furthermore, as shown in FIG. 45, a shift gauge 400a is provided in the vicinity of the position where the manual operation shaft 401 protrudes on the surface of the left case 400L. The shift gauge 400a indicates a rotation range of the bolt 403 by the rotation of the manual operation shaft 401 when connected in the left side view. In the embodiment, the shift gauge 400a is arranged on the left side from the position where the manual operation shaft 401 protrudes. As described above, since the shift gauge 400a is provided, the gear ratio of the hydraulic continuously variable transmission 24 and the like can be known and adjusted easily depending on which part of the shift gauge 400a the bolt 403 is located. . Further, the shift gauge 400a serves as a guide for the amount of operation of the manual operation shaft 401 when the connection is released. Note that a clutch ON position 400b where the main clutch 68 is turned on is formed in the transmission gauge 400a.

(9). Others The present invention can be embodied in various ways other than the above embodiment. For example, the attitude and structure of the mission case 9, the arrangement position of the hydraulic continuously variable transmission, and the like can be arbitrarily set as necessary. For example, the engine 8 can be arranged behind the control floor. Since the power transmission means from the engine 8 to the hydraulic continuously variable transmission 24 is not limited to a belt, power is transmitted via a gear, or the output shaft of the engine 8 and the input shaft of the hydraulic continuously variable transmission 24 are connected. It is also possible to connect directly. The specific shapes of the mission case 9 and the intermediate plate 80 can be arbitrarily changed as necessary. A plurality of intermediate plates 80 may be configured. In this case, the plurality of intermediate plates 80 can be arranged separately in the spreading direction of the opening surface of the main body 9a, or can be arranged separately in the depth direction of the main body 9a ( Therefore, the shaft can be supported by a plurality of intermediate plates 80).

1 traveling machine 4 seedling planting equipment (planting part)
7 Airframe 7a Front side frame 8 Engine 9 Transmission case 10 Front axle case 19 Steering handle 24 Hydraulic continuously variable transmission 35 Power steering unit 39 Torque generator 100 Support bracket 122 Mounting spacer 131 Reinforced connecting plate

Claims

A traveling machine body on which an engine and a transmission case are mounted, and a planting portion that is mounted on the traveling machine body through a link mechanism so as to be movable up and down, and the front wheels are supported by a pair of left and right front axle cases at the front part of the traveling machine body. In the rice transplanter in which the rear wheel is supported by the rear axle case at the rear of the traveling machine body,
The upper end side of each front axle case is attached to the body frame of the traveling body, and the front axle cases are connected to the body frame so that the distance between each other can be adjusted in the horizontal direction.
Rice transplanter.
The left and right front side frames of the fuselage frame are provided with support brackets that extend to the left and right sides of the frame, and the upper end sides of the front axle cases are detachably fastened to the left and right inside or outside of the support bracket. ing,
The rice transplanter according to claim 1.
A spacer is interposed between the support bracket and the upper end side of each front axle case, and the upper end surface of the spacer is in a three-dimensional direction that tilts each front axle case backward and leftward and rightward. Inclined,
The rice transplanter according to claim 2.