JP2013248965A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a transmission case which can work in response to wide variable speed level change by changing a variable speed level of a transmission mechanism in the case, without changing the transmission case.SOLUTION: In a working vehicle for transmitting output of an engine (5) to traveling devices of front wheels (2) and rear wheels (3), etc. through transmission mechanisms (38) and (47) in a transmission case (8), a plurality of transmission mechanisms (38) and (47) are included in the transmission case (8), and it is possible to separate and take out each of the transmission mechanisms (38) and (47) from the inside of the transmission case (8), and also it is possible to assemble the transmission mechanisms (38) and (47) into the transmission case (8) while changing the number of variable speed level of the transmission mechanisms (38) and (47).

Description

  The present invention relates to a work vehicle, and more particularly to a speed change transmission structure in a transmission case in a work vehicle such as a tractor that is an agricultural machine.

  The work vehicle shifts the engine output finely with the transmission mechanism in the transmission case and transmits the power to the traveling wheels to travel at the desired travel speed. It is set. By increasing the number of shared parts in such a multi-model configuration, the production cost of work vehicles is being reduced.

  For example, in Japanese Unexamined Patent Publication No. 2009-208552, in a transmission case composed of a clutch housing case, a center case, and a differential case, a work vehicle having a different gear stage is replaced by replacing the center case with a transmission mechanism for each case. It is considered that.

JP 2009-208552 A

  In the known configuration, since the change in the number of gears is limited to the center case, the change range of the gears is narrow, and the center case, which is a large component, is not a common part, so that the production cost does not decrease much. There are points.

  It is an object of the present invention to provide a mission case configuration for a work vehicle that can cope with a wide range of shift speed changes by changing the shift speed of the speed change mechanism in the case without changing the transmission case.

The problems of the present invention are solved by the following technical means.
According to the first aspect of the present invention, the output of the engine (5) is transmitted to a traveling device such as the front wheels (2) and the rear wheels (3) via the transmission mechanisms (38) and (47) in the transmission case (8). In a work vehicle that transmits power, a plurality of speed change mechanisms (38), (47) are provided in a transmission case (8), and the speed change mechanisms (38), (47) are separated from the transmission case (8) and taken out. In addition, the work vehicle is characterized in that it can be incorporated into the transmission case (8) by changing the number of shift stages of the transmission mechanisms (38), (47).

With this configuration, most of the components other than the transmission mechanisms 38 and 47 of the transmission case 8 are shared, and a transmission case for a work vehicle having a different number of shift stages can be configured.
The invention according to claim 2 is provided with a plurality of transmission shafts (24), (43), (21), (34), (45) for transmitting rotation in the transmission case (8), and the input side transmission shaft. The output vehicle transmission shaft (43), (34), (45) is disposed on the shaft extension of (24), (21).

  With this configuration, the input-side transmission shafts 24 and 21 and the output-side transmission shafts 43, 34, and 45 are aligned in a straight line, and the side wall overhang of the transmission case 8 surrounding this portion is reduced. The volume is reduced, and the weight and cost are reduced.

  According to a third aspect of the present invention, a main transmission branching portion (53) for branching into the traveling transmission shaft (24) and the PTO transmission shaft (28) is provided immediately below the rotation input from the engine (5), and the main transmission is provided. The work vehicle according to claim 2, wherein a forward / reverse reversing mechanism can be incorporated on the traveling transmission shaft (24) side of the branch portion (53).

  In this configuration, when a reverse rotation mechanism is incorporated in the main transmission branching portion 53, a reverse drive is performed in the initial stage of transmission, and a transmission case with a large number of shift stages can be configured by reverse drive with good transmission efficiency.

According to the first aspect of the present invention, almost all components except the speed change mechanisms 38 and 47 of the mission case 8 are shared, and a mission case for a work vehicle having a different number of shift stages can be configured.
In the invention according to claim 2, the input side transmission shafts 24, 21 and the output side transmission shafts 43, 34, 45 are aligned in a straight line, and the side wall overhang of the transmission case 8 surrounding this portion is reduced. As a result, the volume of the mission case 8 is reduced, and the weight and cost are reduced.

  According to the third aspect of the present invention, when a reverse rotation mechanism is incorporated in the main transmission branching section 53, a reverse drive is performed in the initial stage of transmission, and a transmission case with a large number of gear stages can be configured by reverse drive with good transmission efficiency.

It is the whole tractor side view as a work vehicle of the present invention. It is a cross-sectional development view of a mission case. It is a front sectional view of a mission case. It is a partial cross section expanded view of the mission case of another Example. It is a partial cross section figure of a mission case. It is a partial cross section figure of a mission case. It is a partial cross section figure of the mission case of another example. It is a partial cross section figure of a mission case. It is a partial cross section figure of a mission case. It is a partial cross section figure of the mission case of another example. It is a partial cross section figure of the mission case of another example. It is a power transmission diagram in the mission case of another Example.

An example of a tractor will be described below as an example of a work vehicle.
In the present specification, the left and right directions in the forward direction of the work vehicle are referred to as left and right, respectively, the forward direction is referred to as front, and the reverse direction is referred to as rear.

  As shown in FIG. 1, the tractor 1 includes front wheels 2, 2 and rear wheels 3, 3 at the front and rear portions of the fuselage, and the rotation of the engine output shaft 20 of the engine 5 mounted on the front portion of the fuselage A plurality of transmissions are used to decelerate in multiple stages and transmit to the front wheels 2, 2 and the rear wheels 3, 3.

  A steering handle 7 is provided on the handle post 6 in the cabin 190, and a seat 9 is provided behind the steering handle 7. Below the steering handle 7 is provided a forward / reverse lever 10 for switching the advancing direction of the airframe to the front / rear direction. When the forward / reverse lever 10 is shifted to the front side, the airframe moves forward, and when it is shifted to the rear side, it moves backward.

  An accelerator lever 11 for adjusting the engine speed is provided on the opposite side of the forward / reverse lever 10 with the handle post 6 in between, and an accelerator for similarly adjusting the engine speed is provided at the right corner of the step floor 13. The pedal 18 and left and right brake pedals 19R and 19L for operating the left and right rear wheels 3 and 3 are provided.

A meter panel 16 is provided on the front side of the steering handle 7 at the upper part of the handle post 6 to display the vehicle status such as traveling speed.
The main transmission lever 14 for shifting the main transmission mechanism is located on the left front side of the seat 9, the auxiliary transmission lever 15 for shifting the auxiliary transmission mechanism is located behind it, and further the PTO for shifting the PTO output shaft 111 on the right side thereof. A transmission lever 12 is provided.

A rotary working machine 17 is mounted on the rear part of the tractor 1 and is driven by a PTO output shaft 111 protruding rearward from the mission case 8.
FIG. 2 is a cross-sectional development view showing the power transmission mechanism of the transmission in the transmission case 8 in which the front case 8F and the rear case 8R are integrally assembled by the connecting surface 8C. The front wheel 2, the rear wheel 3 and the rotary work from the engine 5 are shown. The speed change transmission mechanism to the PTO output shaft 111 to the machine 17 will be described.

  The rotation of the engine output shaft 20 of the engine 5 is transmitted to the input shaft 21 via the main clutch 112, and the first output gear 22 fixed to the input shaft 21 meshes with the first input gear 23 of the first traveling shaft 24. The second output gear 25 of the input shaft 21 is engaged with the PTO input gear 26 and transmitted to the first PTO shaft 28 via the PTO clutch 27, and further drives the PTO output shaft 111 connected by the sleeve 29. To do. The PTO clutch 27 is a multi-plate clutch, and an oil pump mounting seat 55 for supplying lubricating oil is provided on the outer surface of the front case 8F as shown in FIG. 56 is provided so that lubricating oil can be directly produced.

  A portion where the first output gear 22 meshes with the first input gear 23 of the first traveling shaft 24 is referred to as a main transmission branching portion 53, and the clutch is replaced with the first input gear 23 of the first traveling shaft 24 as shown in FIG. When the gear 23 is assembled and one forward rotation gear 23a of the clutch gear 23 is engaged with the first output gear 22 and the other reverse rotation gear 23b is engaged with the reverse gear 54, the first traveling shaft 24 is rotated forward. Switch to reverse rotation.

  The spline shaft portion 24S of the first travel shaft 24 is slidably fitted with the input-side first-speed / second-speed integrated gear 30 and the input-side third-speed gear 31 so as to be fixed to the second travel shaft 34. A main transmission mechanism that shifts to forward first, second, third, and reverse first speeds by appropriately meshing with a speed gear 35, an output second speed gear 36, an output side third speed gear 37, and a back gear 33 fixed to the idle shaft 32. 38 is constituted. As shown in FIG. 9, the shaft position of the output side third speed gear 37 is such that the first sleeve 57 is interposed between the output side second speed gear 36 and the second sleeve 58 is interposed between the bearing and the bearing. 10, the bulging portion 37a formed on the output side third speed gear 37 and the bulging portion 36a formed on the output side second speed gear 36 are brought into contact with each other, or the output side second speed gear 36 as shown in FIG. And the output-side third gear 37 can be integrated to facilitate assembly.

  In the main transmission mechanism 38, the gear position is changed by increasing / decreasing the gears assembled to the spline shaft portion 24S and the second travel shaft 34, but the front case 8F side is close to the connecting surface 8C between the front case 8F and the rear case 8R. Therefore, it is easy to change the gear position.

The rotation of the second traveling shaft 34 that has been shifted by the main transmission mechanism 38 is transmitted to the third traveling shaft 43 by the fourth gear 40 that meshes with the third gear 39.
A small gear 41 and a large gear 42 are fixed to the third traveling shaft 43, and are appropriately meshed with a large and small slide gear 44 that is spline-fitted to the spline portion of the bevel gear shaft 45, thereby shifting the gear to two stages of high and low. An auxiliary transmission mechanism 47 is configured.

  In the sub-transmission unit 47, the gear stage is changed by increasing or decreasing the gears assembled to the third travel shaft 43 and the bevel gear shaft 45. It is easy to change the gear position.

Since the third traveling shaft 43 is located on the extension of the first traveling shaft 24, it is not necessary to fatten the rear case 8R.
Further, since the second travel shaft 34 and the bevel gear shaft 45 are located on the extension of the input shaft 21, it is not necessary to thicken the front case 8F and the rear case 8R.

The rotation of the bevel gear shaft 45 is transmitted from the bevel gear portion 45 a to the large bevel gear 46 to drive the rear axle 48.
Further, the rotation of the bevel gear shaft 45 is transmitted from the fifth gear 50 fixed to the bevel gear shaft 45 to the large and small gear 49, and is transmitted to the front wheel drive shaft 52 through the front clutch gear 51, and finally drives the front wheel 2. To do.

  FIG. 5 shows a mounting portion of the brake arm 96. A brake arm fulcrum pin 95 for operating the disc brake 94 is sealed with two O-rings 98, and a case protruding portion is formed on a square shaft. The structure is simplified and the cost is reduced by fitting the square holes and tightening the nut 97 to the shaft end.

  FIGS. 6 and 7 are drawings of a portion for locking the differential mechanism. The pin ring 102 provided with the lock pins 101 provided at the circumferentially four equal positions from the shaft side of the differential gear 99 in the differential case 100 is shown in FIG. Thus, the differential is locked by sliding in the axial direction and engaging the lock pin 101 with the differential gear 99.

Then, the four lock pins 101 are made long, and the two long pins engage with the differential gear 99 first, and then the two short pins engage with each other to facilitate smooth engagement.
In FIG. 6, a compression spring 104 is fitted to the lock pin 101 to urge the lock pin 101 in the unlocking direction. In FIG. 7, a tension spring 105 that pulls the pin ring 102 in the releasing direction is provided and attached in the unlocking direction. By releasing the power, the unlocking is surely performed.

FIG. 12 is a power transmission diagram showing a configuration of a transmission in which a hydraulic continuously variable transmission (HST) 60 is incorporated in a power transmission system.
The HST 60 is connected to the engine output shaft 20 of the engine 5 via the main clutch 112, and the PTO first gear 62 fixed to the pump output shaft 61 is engaged with the PTO second gear 63 fixed to the first PTO shaft 28. The PTO output shaft 111 is driven via the clutch 27.

In addition, by using the same distance between the pump output shaft 61 and the first PTO shaft 28 as the configuration without the HST 60, it is possible to increase the number of parts shared with the gear transmission mission case.
Further, the second traveling gear 66, the third traveling gear 67, and the fourth traveling gear 68 are meshed with the first traveling gear 65 fixed to the motor output shaft 64 of the HST 60, and further, the fifth traveling gear is fixed to the first traveling shaft 70. Engage with the traveling gear 69 to transmit. The third traveling gear 67 and the fourth traveling gear 68 are integrally supported by the pump output shaft 61 to save the transmission space.

  In the configuration in which the illustrated fourth traveling gear 68 and the fifth traveling gear 69 are engaged, the vehicle speed can be adjusted and changed by design. However, the fourth traveling gear 68 is eliminated and the third traveling gear 67 is replaced with the third traveling gear 67. By directly meshing with the five traveling gears 69, the number of parts can be reduced.

  Three shift gears 76a of a shift change 76 are fixed to the first travel shaft 70 by a sixth travel gear 71, a seventh travel gear 72, and an eighth travel gear 73, and are spline-fitted to the idle shaft 74 and the travel bevel shaft 79. , 76b, 76c, and the traveling bevel shaft 79 is shifted in three stages.

The rotation of the traveling bevel shaft 79 is transmitted to the rear differential gear 81, the ninth traveling gear 82, and the tenth traveling gear 83 by the bevel gear 80, and drives the rear axle 84 of the rear wheel 3.
The rotation of the traveling bevel shaft 79 is transmitted to the front wheel drive shaft 52 through the eleventh traveling gear 85, the twelfth traveling gear 86, the thirteenth traveling gear 87, and the traveling clutch gear 88, and the front differential gear 89 The front first traveling shaft 90 and the front second traveling shaft 91 are transmitted to the front axle 92 to drive the front wheels 2.

2 Front wheel 3 Rear wheel 5 Engine 8 Transmission case 21 Input shaft 24 First traveling shaft 28 PTO transmission shaft 34 Second traveling shaft 38 Main transmission mechanism 43 Third traveling shaft 45 Bevel gear shaft 47 Sub transmission mechanism 53 Main transmission branching section

Claims (3)

  In a work vehicle in which the output of the engine (5) is transmitted to traveling devices such as the front wheels (2) and the rear wheels (3) via the transmission mechanisms (38) and (47) in the transmission case (8), the transmission case ( 8) a plurality of speed change mechanisms (38), (47) are housed in the interior, and each speed change mechanism (38), (47) can be separated and removed from the transmission case (8). 38) A work vehicle characterized in that it can be incorporated into the transmission case (8) by changing the number of shift stages.   The transmission case (8) is provided with a plurality of transmission shafts (24), (43), (21), (34), (45) for transmitting rotation, and the shafts of the input side transmission shafts (24), (21) The work vehicle according to claim 1, wherein the output side transmission shaft (43), (34), (45) is arranged on the extension.   A main transmission branch portion (53) that branches into a traveling transmission shaft (24) and a PTO transmission shaft (28) is provided immediately below the rotation input from the engine (5), and the traveling transmission shaft of the main transmission branch portion (53) is provided. The work vehicle according to claim 2, wherein a forward / reverse reversing mechanism can be incorporated on the (24) side.

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