JP6384290B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle such as a civil engineering machine or a tractor that travels by driving front and rear wheels.

  The work vehicle shifts the power of an engine mounted on the front of the airframe with a power transmission device in a transmission case provided in the front and rear center of the airframe to drive the front wheels, the rear wheels, and the PTO output shaft.

  For example, as described in Japanese Patent Application Laid-Open No. 2004-69028, the power transmission device of the work vehicle shifts the engine power with a planetary gear type hydraulic transmission device or a hydraulic reverser mechanism built in a transmission case to the rear wheel. It is transmitted to the front wheels via the front wheel speed increasing mechanism.

JP 2004-69028 A

  When the work vehicle is a tractor, a rotary work machine is attached to the rear part of the machine to perform tillage work, so the front part of the machine is heavy so that the front part of the machine does not lift up due to the reaction force of the rotary work machine during work. The balance weight is attached to the front part of the fuselage, but the attachment of the balance weight increases the running load and the fuel consumption rate is deteriorated.

  Therefore, in the present invention, in consideration of the arrangement of various power transmission mechanisms in the transmission case provided in the center of the work vehicle, the front side of the transmission case is made heavy so that the front and rear balance of the aircraft is closer to the front, It is an object of the present invention to enable a work such as a rotary work even if the balance weight provided at the front part of the machine body is eliminated or reduced.

The problems of the present invention are solved by the following technical means.
According to the first aspect of the present invention, in the work vehicle in which the work machine is mounted on the rear part of the machine body and the work machine is driven by the PTO output shaft 10 protruding rearward from the mission case 8 , the plurality of cases constituting the mission case 8 are provided. Among them, the main clutch 105 provided on the front side in the first case 8a formed in the foremost part is reverse to the forward transmission cylinder 11 with the forward / reverse clutch 17 sandwiched below the mission input shaft 12 connected to the engine output shaft 4. The first transmission shaft 14 loosely fitting the transmission cylinder 18 and the idle transmission cylinder 23 receiving the rotation of the forward transmission cylinder 11 by the input gear 24 and transmitting the reverse rotation to the reverse transmission cylinder 18 by the output gear 27 are loosely fitted. The second transmission shaft 25 is provided, and the four-wheel drive clutch 82a of the front wheel 2 and the front-wheel acceleration clutch are partially inserted below the interval between the input gear 24 and the output gear 27 of the idle transmission cylinder 23. Place 82b, the configuration of the work vehicle, characterized in that the interior of the four-wheel drive clutch 82a and the front wheel acceleration clutch 82b to the first casing 8a.

The invention according to claim 2, setting the PTO forward and reverse clutch 26 and PTO clutch 31 to the rear portion of the second transmission shaft 25 only, the forward-reverse clutch 17 and PTO forward and reverse clutch 26 and PTO clutch 31 to the first case 8a It is set as the structure of the work vehicle of Claim 1 characterized by the above-mentioned.

  According to the third aspect of the present invention, a second case 8b that pivotally supports the transmission shaft is provided at the rear part of the first case 8a, and the main transmission mechanism 34 and the sub-transmission mechanism 73 are provided at the rear part of the second case 8b. The construction of the work vehicle according to claim 2, wherein three cases 8c are provided.

  According to a fourth aspect of the present invention, there is provided the work vehicle according to the third aspect, wherein a fourth case 8d having a PTO transmission mechanism 113 for shifting the PTO output shaft 10 is connected to a rear portion of the third case 8c. The configuration is as follows.

According to the first aspect of the present invention, the first transmission shaft 14 and the second transmission shaft 25 are arranged below the input gear 24 and the output gear 27 of the idle transmission cylinder 23 at the lower part of the first transmission shaft 14 and at the forefront of the transmission case 8. Since the heavy four-wheel drive clutch 82a and the front wheel speed increasing clutch 82b are disposed in the first case 8a, the front side of the transmission case having the transmission mechanism is heavy, and the work vehicle on which the transmission case 8 is mounted. As a result, the balance weight attached to the front of the airframe becomes unnecessary or lighter.

Further, by collecting the four-wheel drive clutch 82a and the front wheel acceleration clutch 82b below the forward / reverse clutch 17, the front / rear length of the transmission case that houses the power transmission mechanism can be shortened.
In the invention according to claim 2, in addition to the effect of claim 1, the forward / reverse clutch 17, the PTO forward / reverse clutch 26, and the PTO clutch 31 are housed in the first case 8a. Concentrating on the front, the front side of the transmission case 8 that houses the transmission mechanism becomes heavier, and the number of parts is reduced, resulting in an inexpensive configuration as compared with the case where each clutch is covered with an individual case.

In the invention according to claim 3, in addition to the effect of claim 2, the main transmission mechanism 34 and the sub-transmission mechanism 73 are centrally arranged in the third case 8c, so that the number of assembling steps can be reduced with a compact configuration.
In the invention according to claim 4, in addition to the effect of claim 3, the first case 8a and the third case 8c are installed in the fourth case 8d without installing the PTO transmission mechanism 113. 8a and the third case 8c do not become large.

It is a whole tractor side view shown as a work vehicle of the present invention. It is a power transmission diagram in a mission case. It is a sectional side view of a mission case. It is front part sectional drawing of a mission case. It is a front sectional view of a mission case. It is a side view of a PTO transmission clutch. It is a partial side view of 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 a pair of left and right front wheels 2 and 2 and a pair of left and right rear wheels 3 and 3 on the front and rear portions of the body, and the rotation of the engine output shaft 4 of the engine 5 mounted on the front portion of the body. Is transmitted to the front wheels 2 and 2 and the rear wheels 3 and 3 and the PTO output shaft 10 on the rear wheel 3 of the fuselage. An operator sits on the cockpit 6 provided and operates by operating a steering device such as the steering handle 7.

  A hitch 9 for mounting the rotary work machine 115 and the like is provided at the rear part of the tractor 1 so that various work machines such as the rotary work 115 machine are driven by the PTO output shaft 10 protruding rearward from the mission case 8. . A balance weight 19 is attached to the front of the aircraft so that the front side of the aircraft does not float during work.

FIG. 2 is a power transmission diagram in the mission case 8 and transmits the driving force of the engine 5 to the mission input shaft 12 via the main clutch 105 attached to the engine output shaft 4.
A first transmission shaft 14 is pivotally supported below the mission input shaft 12, and a forward / reverse transmission cylinder 11 is sandwiched between the first transmission shaft 14 and a forward / backward clutch 17 that engages with a fixed clutch gear 16. The reverse transmission cylinder 18 is loosely fitted, and the first gear 15 fixed to the forward transmission cylinder 11 is engaged with the input gear 13 fixed to the transmission input shaft 12 for transmission.

  A second transmission shaft 25 is provided in parallel with the first transmission shaft 14. The idle transmission cylinder 23 is loosely fitted to the second transmission shaft 25, and a third gear (input gear) fixed to the idle transmission cylinder 23 is provided. ) 24 meshes with the second gear 20 fixed to the forward transmission cylinder 11, rotates the idle transmission cylinder 23, and the fourth gear (output gear) 27 fixed to the idle transmission cylinder 23 is fixed to the first idle shaft 28. The reverse transmission cylinder 18 is rotationally driven opposite to the normal transmission cylinder 11 by meshing with the fifth gear 21 fixed to the reverse transmission cylinder 18 via the idle gear 29. Accordingly, when the forward / reverse clutch 17 is engaged with the forward transmission cylinder 11, the first transmission shaft 14 rotates forward via the clutch gear 16, and when the forward / reverse clutch 17 is engaged with the reverse transmission cylinder 18, the clutch gear 16 is interposed. Thus, the first transmission shaft 14 reverses.

  A forward / reverse clutch gear 25a is fixed to the rear portion of the second transmission shaft 25, and a forward / reverse clutch 26 that meshes with the forward / reverse clutch gear 25a is provided. When the reverse transmission cylinder 30a is loosely fitted to the second transmission shaft 25 and the forward / reverse clutch 26 is engaged with the idle transmission cylinder 23, the second transmission shaft 25 is rotated forward, and when the reverse transmission gear cylinder 30a is engaged, the second transmission is performed. The axis 25 reverses. A PTO clutch 31 that engages and disengages the first PTO shaft 36 is attached to the rear end of the second transmission shaft 25. The PTO clutch 31 is driven and connected when a PTO switch provided in the vicinity of the cockpit 6 is turned on to drive the PTO output shaft 10 and is driven when the lift arm of the hitch 9 is rotated upward to raise the rotary work machine 115 and the like. And the drive of the PTO output shaft 10 is stopped.

  A third transmission shaft 33 is connected to the rear end of the first transmission shaft 14 via a first connection sleeve 32. A seventh gear 35 fixed to the rear end of the third transmission shaft 33 is loosely fitted to a first PTO shaft 36 that is juxtaposed with the third transmission shaft 33 and pivotally supported behind the second transmission shaft 25. The first transmission cylinder 37 is engaged with the first transmission gear 38 and is transmitted.

  The first main transmission cylinder 37 is loosely fitted with the second main transmission cylinder 39, the third main transmission cylinder 42 is loosely fitted with the second main transmission cylinder 39, and the main clutch is attached to the rear end of the first main transmission cylinder 37. The main clutch 45 is engaged with the gear 44 fixed.

  An eighth gear 40 and a ninth gear 41 are fixed to the second main transmission cylinder 39, and a tenth gear 43 and an eleventh gear 46 are fixed to the third main transmission cylinder 42, and to the seventh gear 35 of the third transmission shaft 33. The twelfth gear 48 and the eighth gear 40 of the gear transmission cylinder 47 loosely fitted to the pivotally supported fourth transmission shaft 50 are engaged with the thirteenth gear 49 and the tenth gear 43.

  A fourth main transmission cylinder 51 is loosely fitted to the first PTO shaft 36 at the rear portion of the first main transmission cylinder 37. The fourteenth gear 52, the fifteenth gear 53, and the sixteenth gear 54 are fixed to the fourth main transmission cylinder 51, and the fifth main transmission cylinder 55 is loosely fitted. The fifth main transmission cylinder 55 is formed with a seventeenth gear 56 and an eighteenth gear 57, the eighteenth gear 57 is meshed with the nineteenth gear 58 of the gear transmission cylinder 47, and the fifteenth gear 53 is engaged with the first transmission gear 47 of the gear transmission cylinder 47. It meshes with the 20 gear 59.

  A combination of the gears of the first main transmission cylinder 37, the second main transmission cylinder 39, the third main transmission cylinder 42, the fifth main transmission cylinder 55, and the gear transmission cylinder 47, the main gears from the first speed to the fourth speed. When the main clutch 45 is engaged with the eleventh gear 46, the first gear is engaged, the second gear is engaged with the ninth gear 41, the third gear is engaged with the fourteenth gear 52, and the seventeenth gear 56 is engaged. When combined, it becomes 4th.

  The rotation of the fourth main transmission cylinder 51 that is shifted and transmitted is transmitted from the sixteenth gear 54 to the twenty-first gear 61 of the sixth transmission cylinder 60 that is loosely fitted to the fourth transmission shaft 50. The 22nd gear 62 fixed to the sixth transmission cylinder 60 meshes with the 23rd gear 63 of the idle transmission cylinder 64 loosely fitted to the idle shaft 72, and the 24th gear 65 is fixed to the idle transmission cylinder 64.

  A sub-clutch 66 is provided between the sixth transmission cylinder 60 and the gear transmission cylinder 47 so as to be engaged with the fourth transmission shaft 50. When the sub-clutch 66 is engaged with the gear transmission cylinder 47, the high-speed, sixth transmission cylinder is provided. The sub-transmission mechanism 73 is configured to shift to three speeds of low speed when engaged with 60 and to the very low speed when the 25th gear 67 of the sub-clutch 66 is engaged with the 24th gear 65 of the idle transmission cylinder 64.

  The rotation of the fourth transmission shaft 50 shifted by the subtransmission mechanism 73 is transmitted from the small bevel gear 69 at the rear end of the shaft to the large bevel gear 70 of the rear horizontal shaft 71, and from the 27th gear 74 of the rear horizontal shaft 71. The rear wheel shaft 76 on which the rear wheel 3 is mounted is driven through the 28 gear 75.

Further, the rotation of the fourth transmission shaft 50 is transmitted from the 26th gear 68 to the 30th gear 78 of the first front wheel drive shaft 79 through the 29th gear 77 loosely fitted to the fourth main transmission cylinder 51.
The first front wheel drive shaft 79 is connected to a second front wheel drive shaft 81 to which the four wheel drive clutch 82a and the front wheel speed increasing clutch 82b are attached by a second connection sleeve 80, and the first front wheel drive shaft 79 is connected to the second wheel driving clutch 82a and the front wheel speed increasing clutch 82b from the first front wheel driving shaft 82b. The two connecting sleeves 88 are connected to the third front drive shaft 89.

  The four-wheel drive clutch 82a and the front wheel speed-up clutch 82b are engaged with the speed-up gears 84 and 85 and the fine speed-reduction gears 86 and 87 between the idle shaft 83, and are sandwiched between the input gears of the idle transmission cylinder 23. (Third gear) 24 and output gear (fourth gear) 27 are in a state of entering.

The rotation of the third front drive shaft 89 is transmitted to the front wheel shaft 94 on which the front wheel 2 is mounted via the front horizontal shaft 92 and the front vertical shaft 93.
The first PTO shaft 36 is connected to a second PTO shaft 96 by a third connecting sleeve 95 and meshes with a first PTO gear 99 fixed to the second PTO shaft 96 and a second PTO gear 101 loosely fitted to the PTO output shaft 10. ing. As shown in FIG. 6, the PTO output shaft 10 is slidably fitted with a PTO speed change clutch 100, and a shift arm 107 provided on the shift rod 106 is slid to move the PTO speed change clutch 100 to change speed. The ball 108 that positions the shift arm 107 in the transmission groove 106a of the shift rod 106 is pressed by the compression spring 109, but if the ball 108 is engaged with the two transmission grooves 106a by the weak compression spring 109, respectively. It is easy to change gears and make it difficult to change.

  The second PTO gear 101 is rotatably supported on the PTO output shaft 10 by a needle 110, a collar 112, and two washers 111. 6A shows the PTO first speed, FIG. 6B shows the PTO second speed, and FIG. 6C shows the PTO third speed.

  The first transmission gear 103 of the PTO transmission clutch 100 is formed at the front and rear intermediate portions of the second PTO shaft 96 by engaging the PTO transmission clutch 100 with the cylindrical gear clutch portion of the rear second PTO gear 101 by drilling. Meshing with the second PTO gear 98, and the second speed change gear 102 of the PTO speed change clutch 100 is shifted to the third speed by meshing with the third PTO gear 97 formed at the front portion of the second PTO shaft 96. The output shaft 10 is driven. The spline portion of the PTO output shaft 10 is provided with circumferential grooves at predetermined intervals so that it is difficult for the change to come off. It should be noted that the cylindrical gear clutch portion of the second PTO gear 101 can be made inexpensive if it is precision forged. It should be noted that the spline hole of the PTO transmission clutch 100 is pulled out from the front and rear intermediate portions to increase the contact surface pressure of the spline portion, making it difficult to change.

  FIG. 3 is a sectional side view of the transmission case 8, and is configured by integrally connecting the first case 8a, the second case 8b, the third case 8c, and the fourth case 8d from the front. Further, as shown in FIG. 5, the first transmission shaft 14 is disposed directly below the mission input shaft 12, and the second front wheel drive shaft 81 is disposed below the first transmission shaft 12. The second transmission shaft 25 and the first idle shaft 28 are connected to the second transmission shaft. They are arranged on the left and right under the shaft 25.

  The main clutch 105 is disposed at the front 1/3 position of the first case 8a, the forward / reverse clutch 17, the four-wheel drive clutch 82a, and the front wheel acceleration clutch 82b are disposed in the center of the first case 8a. The PTO clutch 31 is disposed at the rear 1/3 position, and as shown in FIG. 4, the transmission input shaft 12, the first transmission shaft 14, and the second transmission are placed on the partition wall 8e at the 1/3 position from the front of the first case 8a. The shaft 25 and the first idle shaft 28 are supported, the third transmission shaft 33 and the first PTO shaft 36 are supported on the second case 8b, and the main transmission mechanism 34 and the sub transmission mechanism 73 are internally provided on the third case 8c. The fourth case 8d includes the rear horizontal shaft 71 and the PTO transmission mechanism 113, and supports the PTO output shaft 10. A clutch switching shaft 121 is pivotally supported above the forward / reverse clutch 17 of the first case 8a.

  FIG. 7 shows an embodiment in which the forward / reverse clutch 17 is an oil pressure switching clutch, and a connection bracket 117 of the first transmission shaft 14 that pivotally supports the forward / reverse clutch 17 and an oil supply plug 119 attached to the outside of the first case 8a. The oil supply passages 120a, 120b, and 120c are connected to each other at 118, and the pressure oil supply passage of the hydraulic device is connected to the oil supply plug 119 to supply the pressure oil to the forward / reverse clutch 17.

  Note that the transmission case can be constructed at low cost by sharing the four-wheel drive clutch 82a and the front wheel acceleration clutch 82b by using the same hydraulic clutch as the forward / reverse clutch 17.

4 Engine output shaft 5 Engine 8 Mission case 8a First case 8b Second case 8c Third case 8d Fourth case 10 PTO output shaft 11 Forward transmission cylinder 12 Mission input shaft 14 First transmission shaft 17 Forward / reverse clutch 18 Reverse transmission cylinder 24 Input gear (third gear)
25 Second transmission shaft 26 PTO forward / reverse clutch 27 Output gear (fourth gear)
31 PTO clutch 34 Main transmission mechanism 50 Fourth transmission shaft 73 Sub transmission mechanism 79 First front wheel drive shaft 81 Second front wheel drive shaft 82a Four wheel drive clutch 82b Front wheel acceleration clutch 105 Main clutch 113 PTO transmission mechanism

Claims (4)

In the work vehicle in which the work machine is mounted on the rear part of the machine body and the work machine is driven by the PTO output shaft (10) projecting rearward from the mission case (8) , of the plurality of cases constituting the mission case (8). The forward / reverse clutch (17) is sandwiched below the transmission input shaft (12) connected to the engine output shaft (4) by the main clutch (105) provided on the front side in the first case (8a) configured as a part. The first transmission shaft (14) in which the forward transmission cylinder (11) and the reverse transmission cylinder (18) are loosely fitted, and the rotation of the forward transmission cylinder (11) is received by the input gear (24) and the output gear (27 ) Is provided with a second transmission shaft (25) loosely fitted with an idle transmission cylinder (23) that transmits reverse rotation to the reverse transmission cylinder (18), and an input gear (24) and an output gear ( 27) part of the space below Front four-wheel drive clutch (82a) and the front wheel acceleration clutch (82b) of (2) was placed in a free state, the four-wheel drive clutch (82a) and the front wheel acceleration clutch (82b) in the first case (8a) A work vehicle characterized by its interior . Only set a PTO clutch (31) and the PTO forward and reverse clutch (26) to the rear of the second transmission shaft (25), the forward-reverse clutch (17) and the PTO reciprocal clutch (26) the PTO clutch (31) first 2. The work vehicle according to claim 1, wherein the work vehicle is housed in a case (8a).   A second case (8b) that pivotally supports the transmission shaft is provided at the rear part of the first case (8a), and a main transmission mechanism (34) and a sub-transmission mechanism (73) are provided at the rear part of the second case (8b). The work vehicle according to claim 2, further comprising a third case (8c).   The work vehicle according to claim 3, wherein a fourth case (8d) having a PTO transmission mechanism (113) for shifting the PTO output shaft (10) is connected to a rear portion of the third case (8c).

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