KR20030082054A - Tractor - Google Patents

Abstract

The present invention is to raise the work machine mounted on the lower side of the running vehicle to the ground high.

The engine 2 is mounted on the front of the traveling vehicle body having the front wheels 19 and the rear wheels 11, and the mission case 3 is installed at the rear of the traveling vehicle body, and the output shaft 2a and the mission of the engine 2 are installed. The mission input shaft 5 installed on the front of the case 3 is connected to the first universal coupling 6 and the lifting machine 24 can be freely mounted between the rear wheels 19 and 11. In the tractor (1), the front wheel drive input shaft (15) is installed at the rear of the front axle housing (14) supporting the front wheels (19) so as to obliquely upward and upwardly upward, and the front wheel drive input shaft (15). The front wheel drive shaft 13 protruding from the mission case 3 is connected to the second universal coupling 17.

The first universal coupling 6 is installed at the center portion in the left and right transverse directions of the traveling vehicle body in a plan view, and the second universal coupling 17 is installed in the right and left transverse direction, and also viewed from the side surface. The 1 universal coupling 6 is provided at a position higher than the second universal coupling 17.

Description

Tractor {Tractor}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a tractor for attaching various work machines to a lower portion of a traveling vehicle body having front and rear wheels, and for mowing work and raising soil.

It is known to attach a work machine such as a mower to the lower part of the traveling vehicle to perform a mowing operation. For example, the tractor shown in Japanese Patent Laid-Open No. 9-272350 is equipped with a mower on the lower side between the front wheel and the rear wheel, and transmits power from the engine side to the mission case with universal coupling, The intermediate PTO shaft protruding from the front of the case and the input shaft of the mower are connected by separate universal couplings to drive the mowing blades of the mower. Similarly, they are installed on the front wheel drive shaft and rear axle housing protruding from the front of the mission case. The front wheel drive input shaft is connected by universal coupling to drive the front wheels.

In general, when moving a rice field or a road after finishing a mowing operation or a lawn mowing operation, it is necessary to fasten the ground high so that a working machine such as a mower does not interfere with running. In the above-described conventional apparatus, the power transmission shaft extends in a forward direction parallel to the ground by approaching the power transmission shaft to a position such that the power transmission shaft for front wheel driving does not interfere when the mower is suspended. It is installed in such a way that the front end of the power transmission shaft is supported on the aircraft frame side by special bearings, and the front axle housing is equipped with a transmission case for positioning the input shaft high, and the input shaft on the transmission case side and the front end of the power transmission shaft are separated. The front wheel was driven through the intermediate shaft.

For this reason, in the conventional apparatus described above, the configuration for driving the front wheels becomes complicated, and furthermore, since bearings, transmission cases, and the like are required, the number of parts increases and the product cost is high.

Therefore, an object of this invention is to obtain the tractor which can be comprised cheaply without interposing a special bearing or an extra transmission case, and can install a working machine, such as a mower, above the ground.

1 is a side view of a tractor,

2 is an enlarged side cross-sectional view of a recess;

3 is a top view of the tractor,

4 is a hydraulic circuit diagram,

5 is an enlarged front view of the main part;

6 is an enlarged side view of the main part;

7 is an enlarged plan view of the main part;

8 is a flat sectional view of the control valve;

9, 10 and 11 are side cross-sectional views of the control valve.

(Explanation of the sign)

1 ... tractor 2 ... engine

3 ... mission case 4 ... hydrostatic stepless transmission

5 ... pump shaft 6 ... first universal coupling

7 ... HST Pump 8 ... Floor

10 ... motor shaft 11 ... rear wheel

13 ... front-wheel drive shaft 14 ... front axle housing

15 ... front-wheel drive input shaft 16 ... input shaft holding case

17 ... 2nd Universal Coupling 19 ... Front Wheel

31 ... gear pump 33 ... control valve

34 ... hydraulic cylinder 38 ... lift arm

40 ... PTO control lever 41 ... hydraulic lifting control lever

49 ... main relief valve 50 ... discharge valve

52 ... main spool

In order to achieve the above object, the present invention has made the following technical means.

That is, in the invention of claim 1, the engine 2 is mounted on the front part of the traveling vehicle body provided with the front wheels 19 and the rear wheels 11, and the mission case 3 is installed on the rear part of the traveling vehicle body, and the engine 2 The work shaft 24 is connected between the front and rear wheels 19 and 11 at the same time as the first universal coupling 6 is connected to the output shaft 2a of the output shaft 2a and the mission input shaft 5 provided on the front of the mission case 3 by the first universal coupling 6. In the tractor (1) equipped with free lifting, the front wheel drive input shaft (15) is installed behind the front axle housing (14) supporting the front wheels (19) by projecting obliquely upward upward and backward. (15) and the front wheel drive shaft 13 protruding from the mission case (3) by a second universal coupling (17) characterized in that the tractor.

Moreover, in the invention of Claim 2, the tractor of Claim 1 WHEREIN: It is characterized by the said work machine 24 being a mower for mowing.

Moreover, in the invention of Claim 3, in the tractor of Claim 1 or 2, the said 1st universal coupling 6 is provided in the center part of the left-right horizontal direction of a traveling vehicle body in plan view, and the said 1st universal With respect to the coupling 6, the second universal coupling 17 is installed to be biased in the horizontal direction, and from the side, the first universal coupling 6 is higher than the second universal coupling 17. It is characterized in that it is installed in.

The action by the above configuration is as follows.

Power from the front wheel drive shaft 13 is transmitted to the front wheel travel input shaft 15 via the second universal coupling 17, and drives the front wheel 19 supported by the front axle housing 14.

During operation, rotational power is transmitted from the intermediate PTO shaft on the mission case side or the front PTO shaft on the front of the engine to rotate the drive unit, and when the work is completed and the paddy field or road is finished, the work machine is suspended.

At this time, the rear end of the front wheel drive input shaft 15 protruding obliquely upward from the rear of the front axle housing rearward is a high position from the ground, and the front wheel drive input shaft 15 and the front wheel drive shaft 13 on the mission case side are removed. Since it is set as the structure connected with the 2 universal coupling 17, the 2nd universal coupling 17 itself can be installed in a high position, and the 2nd universal coupling 17 is not obstructed when lifting a work machine. Therefore, the lifting space of the work machine can be widened between the front wheels 19 and the rear wheels 11.

In particular, since the second universal coupling 17 is installed in the right and left horizontal directions, even a mower having a gear box or the like protruding upward in the upper surface of the work machine can be suspended high.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described based on drawing. First, the configuration will be described, where 1 is a conventionally known tractor which mounts the engine 2 at the front of the body and installs the rotational power of the engine 2 at the front of the mission case 3. The pump shaft 5 of the hydrostatic stepless speed transmission (HST) 4 is transmitted via a first universal coupling 6.

In addition, in the case of a tractor without a hydrostatic stepless speed changer (HST) 4, the rear end of the first universal coupling 6 is directly connected to a mission input shaft provided at the front of the mission case 3. The tractor 1 in the embodiment is provided with a hydrostatic stepless speed changer (HST) 4 at the front of the mission case 3, and the pump shaft 5 of the hydrostatic stepless speed changer (HST) 4 is provided. The first universal coupling 6 is configured to connect to the first universal coupling 6.

The rotational power of the hydrostatic stepless speed changer (HST) 4 is changed according to the amount of stepping of the HST pedal 9 provided on the right side of the floor 8, and the hardness angle of the inclined plate is changed. The rotation speed and the rotation direction of the motor shaft 10 are controlled.

The rotational power of the motor shaft 10 is decelerated by an auxiliary transmission not shown in the mission case 3, and a part thereof is transmitted to the rear axle 12 via the differential gear device to drive the rear wheel 11. Power branched immediately before the differential gear device is transmitted to the front wheel drive shaft 13. The front wheel drive shaft 13 is installed to protrude forward in the front right of the front of the mission case 3, and the front wheel drive input shaft 15 axially supported at the rear of the front wheel drive shaft 13 and the front axle housing 14. Is interlockedly connected via a second universal coupling 17 long in the front-rear direction, and is configured to drive the front wheels 19.

More specifically, the front axle housing 14 is freely supported around the center pivot 37 in the front-rear direction, and a holding case for supporting the front wheel driving input shaft 15 on the right rear side of the front axle housing 14. (16) Desorption is provided freely.

As shown in FIG. 2, the holding case 16 is installed in the front axle housing 14 so that its rear end is inclined upwardly obliquely to the rear and is installed in the front axle housing 14, and the front wheel driving input shaft ( 15 is axially supported, and a front end of the second universal coupling 17 is connected to a rear end of the front wheel driving input shaft 15.

The rear end of the holding case 16 is provided with a cylindrical rubber cover 20 to prevent the intrusion of mud or dust.

In addition, the middle PTO shaft 21 and the rear PTO shaft 22 are respectively provided at two positions of the front lower part and the rear lower part of the mission case 3, and these are the transmission and the PTO clutch (in the mission case 3). Rotational power is transmitted via 23).

The rear PTO shaft 22 is for driving a work machine, for example a rotary tiller, which is connected to the rear of the tractor 1, and the intermediate PTO shaft 21 is between the front wheel 19 and the rear wheel 11. It is used to drive a work machine, such as a weeder 24, mounted below the tractor 1.

The intermediate PTO shaft 21 is provided on the side opposite to the second universal coupling 17 (progressive left) with respect to the first universal coupling 6 in plan view.

In addition, the mower 24 has an input shaft 28 and the intermediate PTO shaft 21 protruding in a rearward direction from the gearbox 26 of the mower 24 by being freely connected to the traveling vehicle by the link mechanism 25. Are interlocked by the third universal coupling 29 to rotate the plurality of blades 30 in the mower 24. The link mechanism 25 for elevating the mower 24 may be driven by a hydraulic cylinder or an electric motor. However, in the present embodiment, the feed back link mechanism 27 is provided at an end of the lift arm 38, which will be described later. ), The mower 24 is moved up and down in accordance with the movement of the lift arm 38.

As the lift arm 38 rotates, the mower 24 moves up and down substantially parallel to the ground. In addition, a gear pump 31 is provided at the front of the mission case 3, and a control valve 33 for lifting and lowering the work machine is freely installed at the upper portion of the gear pump 31. On the other hand, the hydraulic cylinder case 36 which accommodates the single-acting hydraulic cylinder 34 is installed on the upper part of the mission case 3, and the lift arms 38 and 38 are pivotally connected to both left and right sides thereof. have. The gear box 31 is always driven through a gear in the mission case 3 (not shown). The gear pump 31 and the bottom of the mission case 3 are connected via a suction pipe 32, and the hydraulic oil which serves as the mission oil in the mission case 3 is connected to the gear pump 31 through the suction pipe 32. It is configured to suck in the inside.

In addition, the tractor 1 shown in FIG. 1 includes an operation lever 40 for turning on and off the PTO clutch, an operation lever 41 for lifting and lowering a work machine, a seat 42 and a steering wheel 43. The full hydraulic power steering unit 44 and the power steering hydraulic cylinder 45 are provided, and a safety frame 47 is provided at the rear of the chassis 46 of the tractor 1.

Next, the structure of the whole hydraulic system is demonstrated based on the hydraulic circuit diagram shown in FIG.

The control valve 33 placed on the top of the gear pump 31 is formed by integrally assembling the main relief valve 49, the dividing valve 50, and the main spool 52, and the dividing valve 50. Most of the hydraulic oil is transferred to the main spool 52 of the hydraulic lift system, and the remaining hydraulic oil is transferred to the power steering unit 44 via the pipe 53. The main spool 52 is slidably fitted to the control valve 33 and rotates the hydraulic lifting operation lever 41 back and forth to slide the main spool 52 in the longitudinal direction. In the main spool 52, the "up position", "neutral position" and "down position" are set. When the "up position" is set, the hydraulic oil passes from the control valve 33 to the hydraulic cylinder 34 through the pipe 54. ), The lift arm 38 is rotated to the upward direction.

When the cover body 55 having a flow path formed therein is installed in the control valve 33, the flow dividing valve 50 side and the main spool 52 side are connected to the passage 80, and the cover body ( If 55 is removed, an external hydraulic flow path 60 is formed, and when an external hydraulic device, for example, a valve 48 such as a front loader, is connected, the external device can be operated. .

In the all-hydraulic power steering unit 44, the valve 44a is switched by the steering handle 43, hydraulic oil is sent into the hydraulic cylinder 45 for power steering, and the piston rod 45a moves in the left and right directions. The steering wheel 19 is then steered.

The return side of the power steering unit 44 is connected to the PTO valve 63 via the pipe 61, and when the PTO valve 63 is turned ON by the PTO operating lever 40, the PTO clutch 23 is turned on. The intermediate PTO shaft 21 and the rear PTO shaft 22 are rotated as they are connected. In this embodiment, the intermediate PTO shaft 21 and the rear PTO shaft 22 can be rotated alone or simultaneously by operating the shifter in the mission case 3.

The flow path branching the middle of the pipe 61 is connected to the hydrostatic stepless speed transmission (HST) 4 via the PTO relief valve 65 and the charge filter 66 in this order.

The hydrostatic stepless speed transmission (HST) 4 is provided with a low pressure relief 67 and a high pressure relief 68. The HST motor 18 is driven by the driving of the HST pump 7, and the tractor 1 runs.

Next, the configuration of FIGS. 5 to 7 will be briefly described.

FIG. 5 is a view of the periphery of the hydrostatic CVT (HST) 4 when viewed from the front, and the main portion is disposed at the left and right inner ends of the control valve 33 positioned in the lower left direction of the seat 42. A rotating shaft 70 for sliding the spool 52 is provided to protrude horizontally inwardly, and an extension shaft 71 is provided on the rotating shaft 70 to seat the end of the extension shaft 71. The lower end of the hydraulic lifting operation lever 41 located on the right side of 42 is provided.

Thus, since the extension shaft 71 is provided in the rotating shaft 70 which slides the main spool 52, and the hydraulic lifting operation lever 41 is directly installed in this, it operates compared with the method using a link like conventionally. At the same time, since spare parts are not required, the manufacturing cost can be reduced.

FIG. 6 is a view of the hydrostatic continuously variable transmission (HST) 4 and the transmission case 3 when viewed in the horizontal direction, and FIG. 7 is a plan view thereof, and the hydrostatic continuously variable transmission (HST) 4 The cooling fan 72 is provided in front of the pump shaft 5 of the pump shaft, and the main body of the hydrostatic continuously variable transmission (HST) 4 is cooled by the cooling fan 72 while the engine is being driven. The hydraulic oil on the return side from the all-hydraulic power steering unit 44 reaches the PTO valve 63 via the pipe 61, and rotates the valve pivot shaft 74 by rotating the PTO operating lever 40. By switching, the hydraulic fluid is guided to the PTO clutch 23 or discharged to turn the PTO clutch 23 on-off.

Next, the structure of the control valve 33 is demonstrated based on FIGS. 8-11. 8 is a plan sectional view of the control valve, in which the main relief valve 49 and the dividing valve 50 are provided on the left side of the valve body 33A at an appropriate interval before and after. The high pressure hydraulic fluid conveyed from the gear pump 31 enters the valve chamber 50a of the flow dividing valve 50 through a through hole 98 formed in the valve body 33A, and part of the outlet port 76 To the full hydraulic power steering unit 44 via the pipe 53.

The through-hole 78 on the side of the dividing valve 50 and the through-hole 79 on the main spool 52 communicate with the flow path 80 formed in the cover 55, and the main spool. The hydraulic oil entering the chamber 52 is appropriately switched by the slide of the main spool 52 and flows into the hydraulic cylinder 34 in the hydraulic cylinder case 36 from the outlet port 82 through the pipe 54.

In more detail, when the hydraulic lifting operation lever 41 is turned backward and the main spool 52 is moved forward (left in FIG. 8), the half-moon-shaped small opening 84 formed in the main spool 52 is raised. Communication with the chamber 85, the working oil enters the chamber 85 through the opening 84, and flows into the hydraulic cylinder 34 through the outlet port 82.

On the other hand, when the hydraulic lifting operation lever 41 is moved forward and the main spool 52 is moved backward (right in FIG. 7), the hydraulic oil introduced into the hydraulic cylinder 34 is sealed through the same pipe 54. (I) It enters 85, passes through the small opening 84a, and returns to the mission case 3 which is a hydraulic tank.

The hole 86 and the hole 89 of the main spool 52 are in constant communication with each other, the hole 89 communicates with the unloading port 87, and the port 87 is connected to the mission case 3 through a pipe 94. Communicating with

In addition, the relationship between the main spool 52 and the control valve 33 is demonstrated in detail based on FIG. 9, FIG. 10, and FIG. All of these figures are the cross section which looked at the control valve 33 from the right side, FIG. 8 is sectional drawing when the main spool 52 is in a neutral position, and FIG. 9 is sectional drawing when the main spool 52 is in a descending position. 11 is a cross-sectional view when the main spool 52 is in the raised position.

The notch part 91 for positioning is formed in the outer periphery part of the front end of the rotating shaft 70 which slides the main spool 52 back and forth, and the spring 92 is biased. The detent ball 93 of the made steel enters the notch 91 to maintain the neutral state of the main spool 52.

A shifter 95 for sliding the main spool 52 is attached to the inner end of the rotation shaft 70 in a downward direction, and a lower end of the shifter 95 is formed with a recess 96 formed in an upper portion of the main spool 52. )

The main spool 52 has three large diameter portions 52A, 52B and 52C and two small diameter portions 52d and 52e in the longitudinal direction thereof, and when the main spool 52 is neutral, a gear pump ( 31, the chamber 97 into which the high pressure hydraulic oil flows from and the chamber 90 in the vicinity thereof communicate with each other, so that the hydraulic oil flows from the chamber 97 toward the chamber 90, and all of the hydraulic oil flows into the mission case 3 into a so-called unloaded state. . A damper chamber 99 is formed on the rear side of the yarn 90 in communication with the yarn 90, the inner diameter of which is slightly larger than the large diameter portion 52C of the main spool 52.

In the damper chamber 99, the large diameter portion 52C of the main spool 52 is damper when the hydraulic lifting operation lever 41 is pushed down and the main spool 52 is slid backward (left in FIG. 10). By giving resistance at the moment of entering into the seal 99, it is possible to recognize that the load change is transmitted to the operator who operates the hydraulic lifting operation lever 41 to the lowering direction, so that the lowering operation is effectively operated.

When the hydraulic lifting operation lever 41 is operated downward, the hydraulic oil in the hydraulic cylinder 34 is connected to the pipe 54, the seal 85, the opening 84a, the holes 86 and 89, and the port 87. Then, the pipe 94 is sequentially returned to the mission case 3.

On the other hand, as shown in FIG. 11, when the hydraulic lifting operation lever 41 is operated to the upward direction, the main spool 52 moves to the front side (right side in FIG. 11), and the large diameter part of the rear end of the main spool 52 ( 52C) blocks the communication between yarn 90 and yarn 97. Then, the high pressure hydraulic oil from the gear pump 31 passes through the opening 84 from the seal 97 into the seal 85, flows into the hydraulic cylinder 34 through the outlet port 82 and the pipe 83, and lifts the lift arm ( 38) increase.

In the invention of claim 1, the engine 2 is mounted to the front of the traveling vehicle body including the front wheels 19 and the rear wheels 11, and the mission case 3 is installed to the rear of the traveling vehicle body. The first universal coupling 6 is connected to the output shaft 2a and the mission input shaft 5 provided on the front of the mission case 3, and the work machine 24 can be freely lifted between the front and rear wheels 19 and 11. In the mounted tractor (1), the front wheel drive input shaft (15) is installed behind the front axle housing (14) supporting the front wheels (19) by projecting obliquely upward upward, and the front wheel drive input shaft (15). ) And the front wheel drive shaft 13 protruding from the mission case 3 by the second universal coupling 17, a sufficient work machine lifting space between the front wheel 19 and the rear wheel 11 can be secured. , The work machine mounted on the underside of the driving body can be suspended high above the ground Can be facilitated.

Further, since the second universal coupling 17 for driving the front wheels 19 is not directly bearing-supported to the vehicle body, the second universal coupling 17 is directly connected to the front wheel driving input shaft 15 protruding obliquely upwards backwards. The second universal coupling 17 can also be installed at a ground level, thereby ensuring sufficient lifting space for the work machine, and at the same time, making the configuration simple and making the number of parts small and inexpensive.

In particular, in the case of attaching a mower as a working machine, as in the invention of claim 2, the mower of the mower does not have a fear that the gearbox or the like driving the knife is in contact with the second universal coupling 17, so Can be.

In addition, the invention of claim 3 is that the first universal coupling 6 is installed at the center portion in the left and right transverse directions of the traveling vehicle body in a plan view, and has a second universal couple with respect to the first universal coupling 6. Rotation of the engine 2 is because the ring 17 is provided to be biased in the horizontal direction and the first universal coupling 6 is installed at a position higher than the second universal coupling 17 when viewed from the side. The power is smoothly transmitted to the power transmission part on the side of the mission case 3 without any trouble, and the power transmission to the front wheels 19 is also ensured by the second universal coupling 17 passing through a high position from the ground. It is delivered without any problem, even if the work machine is installed between the front and rear wheels (19, 11), it can be suspended high.

Claims (3)

The engine 2 is mounted on the front of the traveling vehicle body having the front wheels 19 and the rear wheels 11, and the mission case 3 is installed at the rear of the traveling vehicle body, and the output shaft 2a and the mission of the engine 2 are installed. The tractor 1 which connects the mission input shaft 5 installed on the front of the case 3 with the first universal coupling 6 and freely lifts and attaches the work machine 24 between the front and rear wheels 19 and 11. In the rear part of the front axle housing 14 supporting the front wheels 19, the front wheel driving input shaft 15 is installed to be projected obliquely upward upward, and the front wheel driving input shaft 15 and the mission case ( A tractor characterized in that the front wheel drive shaft (13) projecting from (3) is connected with a second universal coupling (17). The method of claim 1, The work machine (24) is a tractor, characterized in that the mower (mower) for mowing. The method according to claim 1 or 2, The first universal coupling 6 is installed at the center portion in the left and right transverse directions of the traveling vehicle body in a plan view, and the second universal coupling 17 is in the left and right transverse direction with respect to the first universal coupling 6. And the first universal coupling (6) is installed at a position higher than the second universal coupling (17) when viewed from the side.