JP4429092B2 - Tractor - Google Patents

Description

The present invention relates to a tractor suitable for work in a field with a lot of muddy water.

In tractors , it is common to arrange a transmission system below the boarding step from the output shaft of the engine deployed in front of the boarding driver to the input shaft of the mission case deployed behind the boarding driver, In order to facilitate the arrangement of such a transmission system, the engine and the transmission case are arranged such that the height position of their output shaft and input shaft is lower than the height position of the boarding step in the boarding operation section. (For example, refer patent document 1).
Japanese Patent Laid-Open No. 7-277019

In the above configuration, the muddy water splashed as the aircraft travels is likely to adhere to the output shaft of the engine and its peripheral parts, the input shaft of the mission case and its peripheral parts, and the transmission system over them. Therefore, when the tractor constructed in this way is used in a field with a lot of muddy water, the muddy water adheres to the above-mentioned places and the like. Between parts, between the input shaft in the transmission case and its support, or between each member in the transmission system, and wear against oil seals and bearings interposed between them. There is a risk of adverse effects such as.

An object of the present invention is to provide a tractor suitable for work in a field with a lot of muddy water that can effectively prevent the occurrence of problems caused by muddy water.

As means for solving the above-mentioned problems, in the present invention, an engine is arranged on the front side of a boarding operation unit including a boarding step and a driver seat, and a mission is provided below the driver seat on the rear side of the boarding step. deploying cases, the engine and the transmission case and partitioned deployed in front and back of the boarding step, the engine height position of the output shaft, and said transmission case the height position of the input shaft but arranged so that each higher than the height position of the boarding step, the transmission system over the input shaft from the output shaft, bypassing the pedal operation portion formed on the boarding step in a plan view from the body outer side as such, as well as deployed state of being laterally displaced one side on the floor surface in the boarding step, over the input shaft from said output shaft The dynamic system, so that the transmission downstream side portion as viewed from the side is longitudinal direction along the floor surface, are formed by bending the front and rear intermediate portion shaped want is displaced downward.

  According to this configuration, muddy water splashed as the aircraft travels is unlikely to adhere to the output shaft of the engine and its surrounding parts, the input shaft of the mission case and its surrounding parts, and the transmission system over them. Therefore, even when used in fields with a lot of muddy water, it becomes possible to effectively suppress muddy water from adhering to those places. Between the input shaft in the transmission case and its support, or between the members in the transmission system, etc., and adverse effects such as wear on the oil seals and bearings interposed between them. It is possible to prevent the risk of affecting

  In addition, it is possible to avoid the inconvenience that the operation of each operation pedal provided for the boarding step is obstructed by the transmission system arranged on the floor surface of the boarding step, and the airframe generated when the transmission system is deployed laterally outside the boarding step The increase in the lateral width can be prevented, and the support structure for the transmission system can be simplified.

Therefore, while simplifying the support structure for the transmission system, the output shaft of the engine, the input shaft of the mission case, or the transmission system over them, etc. without causing a decrease in the operability of each operation pedal or an increase in the body width Therefore, it has been possible to provide a tractor suitable for work in a field with a lot of muddy water, which can effectively prevent the occurrence of problems caused by muddy water adhering to the muddy water.
Further, the transmission system extending from the output shaft to the input shaft is bent and formed in a dogleg shape so that the lower middle portion thereof is displaced downward so that the lower side portion of the transmission is in the front-rear direction along the floor surface in a side view. Thereby, the feeling of opening given to the operator of the boarding operation part can be improved, and the comfort in the boarding operation part can be improved.

As one of means for making the present invention more suitable, the output shaft and the input shaft are extended toward the left and right sides of the airframe, and the transmission system is connected to the output shaft and the input shaft. over extended end portions are constituted in the belt transmission type having a transmission belt.

  According to this configuration, the transmission system is compared to the case where the transmission system is configured as a shaft transmission type that requires a relatively expensive bevel gear and requires high accuracy in alignment with the output shaft of the engine and the input shaft of the transmission case. Therefore, it is possible to reduce costs and improve assembly.

  As one of means for making the present invention more suitable, the transmission case is formed such that an output portion having a traveling output shaft is positioned at the lowest position.

  According to this configuration, the ground height of the mission case can be set to the maximum state in which no part other than the output part in the mission case is positioned lower than the output part. The muddy water splashed up can be made more difficult to adhere to the transmission case and the transmission system that is transmitted to its input shaft. , Between the input shaft in the transmission case and its support, or between the members in the transmission system, etc., and have an adverse effect such as wear on oil seals and bearings interposed between them. The fear can be prevented more reliably.

  Therefore, it is possible to more surely prevent the occurrence of problems caused by mud water adhering to the transmission case and the transmission system that transmits to the input shaft.

  As one of means for making the present invention more suitable, a plurality of oil seals are arranged in parallel between the transmission case and the output shaft for traveling, and are installed at the outermost position of the transmission case. The oil seal is configured to be detachable from the outside of the mission case.

  In this configuration, in the mission case, a plurality of oil seals are arranged side by side in consideration of the location where the traveling output shaft is difficult to prevent muddy water adhesion. By this, even if muddy water enters between the output shaft for traveling in the mission case and its support part, the oil seal located at the outermost position of the mission case can be limited to the extent that it is worn out. It is possible to reliably prevent the bearings from being worn out.

  Also, even if the oil seal located at the outermost position of the mission case is worn out by muddy water, this oil seal can be easily replaced from the outside of the mission case without the need to drain the oil in the mission case. Therefore, it is possible to quickly cope with the wear of the oil seal, and it is easy to prevent the expansion of damage due to adhesion of muddy water.

  Therefore, it is possible to effectively prevent the occurrence of problems caused by the muddy water adhering to the part having the output shaft for traveling in the mission case.

  As one of means for making the present invention more suitable, the transmission case includes a traveling transmission and a rear wheel differential, and the transmission operating shaft of the transmission and the difference for the rear wheel are provided. An operation shaft of a lock mechanism that enables differential blocking of the moving device is arranged on the upper part of the mission case so as to be higher than the height position of the boarding step.

  According to this configuration, the muddy water splashed as the aircraft travels hardly adheres to the transmission operation shaft of the transmission provided in the transmission case, the operation shaft of the lock mechanism, and the operation system linked thereto. Since muddy water can effectively be prevented from adhering to them, the muddy water is placed between the speed change operation shaft in the mission case, the operation shaft and their support, or between each member of the operation system. By entering, it is possible to prevent the possibility of adverse effects such as wear on the oil seals interposed between the operation shafts and their support portions, the operation systems linked to the operation shafts, and the like.

  Therefore, it is possible to effectively prevent the occurrence of problems caused by the muddy water adhering to the transmission operation system or the differential operation system of the mission case.

  As means for solving the above-mentioned problems, in the present invention, the transmission case is equipped with a power take-off shaft, and an auxiliary transmission system extending from the input shaft to the power take-off shaft is provided above the inside of the mission case. It is.

  According to this configuration, even if the transmission case is equipped with an auxiliary transmission system and a power take-off shaft for extracting power for work, etc., it can be avoided that the ground height of the mission case is lowered, and the aircraft can be run. The muddy water splashed up can be maintained in a state where it is difficult to adhere to the mission case or power take-off shaft, etc., and muddy water can be effectively suppressed from adhering to it, so that the muddy water is between the power take-out shaft and its support part It is possible to prevent the possibility that the oil seals or the bearings interposed between them will have an adverse effect such as wear.

  Therefore, it is possible to effectively prevent the occurrence of malfunctions due to muddy water adhering to the power take-off shaft and its peripheral portion in the mission case while enabling the take-out of power for work from the mission case.

  As one of means for making the present invention more suitable, the auxiliary transmission system is configured as a shaft transmission type including an auxiliary transmission shaft extending from the input shaft to the power take-off shaft, and the auxiliary transmission shaft is provided. Is set to a posture that intersects the posture of each transmission shaft of the traveling transmission system extending from the input shaft to the traveling output shaft.

  According to this configuration, the auxiliary transmission shaft is effectively used between the gears and shift forks mounted on each transmission shaft of the traveling transmission system in the transmission case, or between each transmission shaft and each operating shaft of the traveling transmission system. And can be deployed to pass between them.

  Therefore, it is possible to suppress the increase in size of the transmission case due to the auxiliary transmission system that enables extraction of power for work from the transmission case, and thus, the transmission of the transmission case can be suppressed. While deploying at a relatively high position, it is possible to avoid a decrease in stability due to an increase in the center of gravity of the aircraft.

Entire left side bets Rakuta in FIG. 1, the entire right side surface in FIG. 2, the overall plan in FIG. 3, the overall perspective viewed from the front right in FIG. 4, the left rear in FIG. 5 FIG. 6 shows an overall perspective view as viewed from above, and FIG. 6 shows a schematic overall left side surface thereof. The tractor is formed on a body frame 1 formed in a frame shape with a steel strip or the like, and on the rear side thereof. A boarding operation unit 2, an engine 3 mounted on the front of the body frame 1, a transmission case 4 combined with the rear end of the body frame 1, front wheels 5 disposed on the front left and right of the body frame 1, A rear wheel 6 disposed on the left and right of the mission case 4, a hydraulic lift cylinder 7 disposed above the mission case 4, a pair of left and right lift arms 8 that swing up and down by the operation of the lift cylinder 7, etc. That is composed of In part, and the working device, or trailer, such as an unshown disc plow and rotary cultivator, is adapted to be connected via a link mechanism 9.

  The boarding operation unit 2 includes a boarding step 10 laid on the rear side of the body frame 1, a steering wheel 11 that steers the left and right front wheels 4, and an operation that is disposed behind the steering wheel 11 at a predetermined interval. The seat 12 is formed.

  As shown in FIGS. 1 to 9, the engine 3 has a body frame 1 so that its output shaft 13 extends toward the left side of the body and is positioned higher than the boarding step 10. This is a horizontal diesel engine mounted on the front of the transmission, and its power is transmitted to the input shaft 16 of the transmission case 4 via a belt-type transmission (an example of a transmission system) 14 and a dry multi-plate main clutch 15. Communicated.

  As shown in FIGS. 1 to 5 and FIGS. 8 to 11, the mission case 4 is input to the input shaft 16 based on the operation of the main speed change lever 17 arranged on the left side of the driver seat 12 in the boarding operation unit 2. Gears that switch between a state where the power is reversed for reverse, a state where the gear is shifted to a low speed for rotary tillage work, a state where the speed is shifted to a medium speed for disk plow work, and a state where the speed is changed to a high speed for trailer work A gear-type sub-transmission device 20 that switches the power after shifting by the main transmission 18 to high and low two stages based on the operation of the sub-transmission lever 19 disposed behind the main transmission lever 18 and the main transmission lever 17. A rear wheel differential device 22 that transmits power after shifting by the transmission device 20 to the left and right relay shafts 21 in a state in which differential rotation thereof is allowed, and is disposed on the lower right side of the driver seat 12 in the riding operation unit 2. De Based on the depression operation of the lock pedal 23, the lock mechanism 24 that is switched from a state that allows the differential of the left and right relay shafts 21 by the rear wheel differential device 22 to a state that blocks the differential, and the left and right relay shafts 21 A transmission gear 26 that transmits to the rear axle as a traveling output shaft 25 is built in as a traveling transmission system 27.

  As shown in FIGS. 7 to 11, the mission case 4 has a four-divided structure that can be divided into first to fourth case bodies 28 to 31 in the left-right direction of the aircraft, and the first case body 28, the second case body 29, and the like. Thus, the input shaft 16 provided at the front end thereof is supported so as to extend toward the left side of the machine body, and between the first case body 28 and the second case body 29, the main transmission 18 and The auxiliary transmission 20 and the rear wheel differential 22 are accommodated, and the lock mechanism 24, the left relay shaft 21 and the transmission gear 26 are accommodated between the first case body 28 and the third case body 30. The first case body 28 and the third case body 30 support the left rear axle 25 in a state of extending toward the left side of the machine body, and between the second case body 29 and the fourth case body 31. The right relay shaft 21 and the transmission gear 26 are housed in the second case body 29 and the fourth gear. The output body 32 is configured to support the right rear axle 25 so as to extend toward the right side of the airframe, and includes the left and right rear axles 25 and the transmission gear 26. It is located at the bottom of the rearmost part, and is formed in an upwardly rising slope shape that is located higher on the front end side including the input shaft 16, and the upper half including the input shaft 16 and the like is higher than the boarding step 10 Deployed to be in position.

  As shown in FIGS. 8 to 11, the first shift gear 33 of the main transmission 18 is disposed at the upper part of the transmission case 4 via the first shift fork 34 and the low-speed position F <b> 1 for the rotary tillage work. , F2 and the first operating shaft 35 for sliding operation, the second shift gear 36 of the main transmission 18 through the second shift fork 37, medium speed positions F3, F4 for disc plow work, and trailer work A third operation for slidingly operating the second operating shaft 38 that slides between the high speed positions F5 and F6 and the shift gear 39 of the auxiliary transmission 20 between the low speed position L and the high speed position H via the third shift fork 40. A shaft 41 and a fourth operation shaft 44 that slides the shift claw 42 of the lock mechanism 24 across the lock position and the release position via the fourth shift fork 43, and the like. It is Bei.

  3 and 12, the first operating shaft 35 and the second operating shaft 38 are the main transmission lever 17, the third operating shaft 41 is the auxiliary transmission lever 19, and the fourth operating shaft 44 is the diff lock. The pedals 23 are linked to the pedals 23 through corresponding linkage mechanisms (not shown), and the shift lever 17 is moved along the guide grooves 45 formed in an H shape so that the reverse positions R1 and R2 and the low speed for rotary tillage work. By operating to positions F1, F2, medium speed positions F3, F4 for disc plow work, or high speed positions F5, F6 for trailer work, the reverse state, the low speed state for rotary tillage work, and the disk plow work It is possible to switch between a medium speed state for trailer and a high speed state for trailer work, and after displaying any of these states, the sub-shift lever 19 is moved to a low speed position L or a high speed position. Operate to H It is, their respective states further adapted to be switched to high and low stages.

  By the way, the speed at low speed for rotary tillage work is about 1.1 km / h, the speed at high speed for rotary tillage work is about 1.7 km / h, and the speed at low speed for disk plow work. Is about 3.8 km / h, the speed at high speed for disc plow work is about 5.9 km / h, the speed at low speed for trailer work is about 13.7 km / h, and for trailer work The speed in the low speed state is set to about 21.6 km / h.

  As shown in FIGS. 2 to 4, 8, and 9, boarding is performed between the first case body 28 and the third case body 30 and between the second case body 29 and the fourth case body 31. A wet multi-plate brake 47 that applies a braking force corresponding to the amount of operation to the corresponding relay shaft 21 based on the depressing operation of the corresponding pair of left and right brake pedals 46 disposed on the right front portion of the driving unit 2 is provided. Each is housed.

  As shown in FIGS. 8 and 9, the third case body 30 and the fourth case body 31 are equipped with operation shafts 48 for braking the corresponding brakes 47, and the operation shafts 48 and the first support shafts for supporting them. An oil seal 49 is interposed between the three case body 30 and the support portion of the fourth case body 31 so as to be detachable from the outside of the transmission case 4.

  Further, as shown in FIG. 11, an oil seal 49 is also provided between the first to fourth operation shafts 35, 38, 41, 44 described above and the support portion of the first case body 28 that supports them. The mission case 4 is interposed so as to be detachable from the outside.

  As shown in FIGS. 8 and 13, the left rear axle 25 and the support portion of the third case body 30 that supports the outer side of the left rear axle 25 and the right rear axle 25 and the outer side thereof are supported. Two oil seals 50 and 51 are provided in parallel with the support portion of the fourth case body 31, and the oil seal 51 provided on the outer side of the machine body among the oil seals 50 and 51. Is configured to be removable from the outside of the mission case 4.

  And in the 3rd case body 30 and the outer end of each support part in the 4th case body 31, the cover 52 which prevents adhesion and penetration | invasion of muddy water etc. between the right and left rear axle 25 and each support part, respectively is each provided. It is installed.

  As shown in FIGS. 7 to 10, the first case body 28 is deeply formed so as to have a large volume that accommodates substantially the entire main transmission 18, auxiliary transmission 20, and rear wheel differential 22. The rear end portion is provided with a power take-out portion 54 detachably equipped with a power take-out unit 53.

  As shown in FIG. 10, the power take-off unit 53 is connected to a substantially cylindrical support body 55 that is bolted to the first case body 28 via a first bearing 56 and a pair of oil seals 57 and 58. A power take-out shaft 59 that enables transmission to the device or the like is supported, and a bevel gear 60 and a second bearing 61 are mounted on the end of the power take-out shaft 59 on the transmission case 4 side.

  Of the pair of oil seals 57, 58, the oil seal 58 provided on the outer side of the machine body is configured to be detachable from the outside of the mission case 4.

  As shown in FIGS. 8 to 11 and FIG. 14, the second case body 29 includes the input shaft 16 and the right end portions of the transmission shafts 62 to 65 of the main transmission 18 and the auxiliary transmission 20 arranged in parallel therewith. A support 67 that detachably supports an auxiliary transmission system 66 that enables transmission from the input shaft 16 to the power take-off shaft 59 is provided in the front and rear of the upper portion of the lid that is shallow enough to support. The support body 67 includes a first support portion 68 that is bolted to the second case body 29, and a second support portion 69 that is bolted to the second case body 29 together with the first support portion 68. It is configured in a two-part structure.

  The auxiliary transmission system 66 is a shaft transmission in which bevel gears 71 and 72 are provided at both ends of an auxiliary transmission shaft 70 arranged in an orthogonal posture with respect to the input shaft 16 and the transmission shafts 62 to 65 of the main transmission 18 and the auxiliary transmission 20. The auxiliary transmission shaft 70 is supported by the front and rear support bodies 67 via bearings 73, the bevel gear 71 on one end side meshes with the bevel gear 74 equipped on the input shaft 16, and the bevel gear 72 on the other end side Engage with the bevel gear 60 of the power take-out unit 53.

  An auxiliary clutch 76 for switching the transmission state from the input shaft 16 to the power take-off shaft 59 is interposed between the input shaft 16 and the bevel gear 74, and the upper parts of the first case body 28 and the second case body 29 are A fifth operating shaft 79 is provided for sliding the shift member 77 of the auxiliary clutch 76 through a fifth shift fork 78 between a transmission entering position and a transmission cutting position, and this fifth operating shaft 79 is used for boarding operation. The auxiliary clutch lever 80 (see FIGS. 1, 2, and 4) provided on the right side of the driver seat 12 in the portion 2 is linked through a linkage mechanism (not shown).

  Although not shown, an oil seal 49 is also provided between the fifth operation shaft 79 and the support portions of the first case body 28 and the second case body 29 that support the fifth operation shaft 79 from the outside of the transmission case 4. It is interposed so that it can be attached and detached.

  From the above configuration, first, the transmission case 4 has the input case 16, the main transmission 18, the auxiliary transmission 20, the rear wheel differential 22, the left rear axle 25, the power take-off, in the first case body 28. After the unit 53, the auxiliary clutch 76, etc. are supported, the second case body 29, which supports and equips the right rear axle 25, the auxiliary transmission system 66, etc., is connected by bolts, and the left relay in the rear wheel differential 22 is connected. After the shaft 21 is equipped with the lock mechanism 24 and the brake 47 and the transmission gear 26 is mounted on the left rear axle 25, the third case body 30 is bolted to the first case body 28, and the rear wheel differential After mounting the brake 47 on the right relay shaft 21 in the moving device 22 and mounting the transmission gear 26 on the right rear axle 25, the fourth case body 31 and the second case body 29 are attached to the first case body 28. Bolt series Such as by, it adapted to be assembled relatively easily.

  The oil seals 49, 51, 58 other than the inner oil seals 50, 57 can be easily replaced from the outside of the mission case 4 without disassembling the mission case 4. Since the seal portion located at a lower position has a double structure, it is not necessary to drain the oil in the transmission case 4 when replacing the outer oil seals 51, 58. As a result, the oil seals 49, 51 are eliminated. , 58 can be dealt with quickly.

  As shown in FIGS. 1 to 6, 8, and 9, the belt type transmission device 14 includes an output pulley 81 attached to an extended end portion of the output shaft 13 in the engine 3, and an extension of the input shaft 16 in the transmission case 4. The transmission belt 83 passes through the left outer side of the clutch pedal 85 for main clutch operation provided on the left front portion of the boarding step 10 on the floor surface 84 of the boarding step 10 over the input pulley 82 attached to the leading end. By being turned around, the pedal operation unit 86 formed in the boarding step 10 is arranged to be displaced to the left side of the boarding step 10 so as to bypass the pedal operation unit 86, and the transmission lower side portion of the transmission cover 87 is the floor surface 84. Is bent in a U-shape so that the intermediate portion is displaced downward so as to be placed on the floor surface 84 in a posture along the direction.

  As shown in FIG. 6, the belt-type transmission device 14 is located on the right side of the belt-type transmission device 14 closer to the center of the boarding step 10 than the belt-type transmission device 14, and is located on the lower left rear side of the engine 3. A gear pump (an example of a hydraulic pump) 89 driven by power from the engine 3 via a belt-driven auxiliary transmission device 88 disposed adjacent to the right side of the vehicle is located above the floor surface 84 of the boarding step 10. Deployed in a state.

  From the above configuration, the output shaft 13 of the engine 3 and its peripheral parts, the input shaft 16 of the mission case 4 and the operation shafts 35, 38, 41, 44, 48, 79 or their peripheral parts, the belt-type transmission 14, The auxiliary transmission device 88, the gear pump 89, and the like are located at a position higher than the height position of the boarding step 10, and this is a case where the tractor is driven in a paddy field with a lot of muddy water. In addition, the muddy water splashed by the front and rear wheels 5, 6 as the vehicle travels causes the output shaft 13 of the engine 3 and its peripheral parts, the input shaft 16 of the mission case 4, and the operation shafts 35, 38, 41, 44, 48, 79 or their peripheral parts, the belt type transmission device 14, the auxiliary transmission device 88, the gear pump 89, etc. Even if it is used, muddy water can be effectively prevented from adhering to those places and the like, and the muddy water is between the output shaft 13 of the engine 3 and its support part, between the input shaft 16 and each operation shaft 35 of the mission case 4. , 38, 41, 44, 48, 79 and their support parts, between the pulleys 81, 82 of the belt-type transmission 14 and the transmission belt 83, or each member of the auxiliary transmission 88 and the gear pump 89. It is possible to prevent the possibility that the oil seals 49, 51, 58, the transmission belt 83, etc. interposed between them may be adversely affected such as wear.

  Further, by providing the belt type transmission device 14 on the floor surface 84 of the boarding step 10, it is possible to prevent an increase in the lateral width of the airframe that occurs when the belt type transmission device 14 is installed laterally outside the boarding step 10. Thus, the support structure for the belt-type transmission device 14 can be simplified, and the belt-type transmission device 14 is installed on the floor surface 84 of the boarding step 10 while the belt-type transmission device 14 is installed. The inconvenience that the operation of each operation pedal 23, 46, 85 provided in step 10 is hindered can be avoided, and the lower transmission side portion of the belt type transmission device 14 located on the floor surface 84 of the boarding step 10 Compared with the case where it is located at a high position at a predetermined distance from 84, the feeling of opening given to the operator of the boarding operation unit 2 is improved. It can be.

  As shown in FIG. 10, the power take-off unit 53 is provided by effectively utilizing a gap formed between the left and right transmission gears 26 in the mission case 4, and the auxiliary transmission system 66 has an auxiliary transmission shaft. 70 effectively uses the gaps formed between the transmission shafts 62 to 65 of the main transmission 18 and the auxiliary transmission 20 in the transmission case 4 and the operation shafts 35, 38, 41, 44, etc. It is arranged so as to pass through the gap, and this makes it possible to increase the size of the mission case 4 due to the auxiliary transmission system 66 that enables extraction of power for work from the mission case 4 and the like. The mission case 4 can be placed at a relatively high position where mud water adhesion can be suppressed, while avoiding a decrease in stability due to the rise in the center of gravity of the aircraft. .

  Further, since the power take-out unit 53 and the auxiliary transmission system 66 can be attached to and detached from the mission case 4, for example, work power can be taken out from the mission case 4 like a disk plow work or a trailer work. In the case of targeting a user who performs only unnecessary work, an inexpensive specification in which the power take-out unit 53 and the auxiliary transmission system 66 are removed can be provided.

  As shown in FIGS. 1-7, the fuel tank 90, the muffler 91, etc. are arrange | positioned at the upper part of the engine 3 mounted on the left-right center of a body, and the battery 92 is arrange | positioned at the front lower part. Further, just below the engine 3, hydraulic oil that is less susceptible to the adverse effects of mud water adhesion by effectively utilizing the lower space of the engine 3 obtained by arranging the engine 3 at a relatively high position where mud water adhesion can be suppressed can be used. A tank 93 is provided.

  In other words, the battery 92 and the hydraulic oil tank 93, which are relatively heavy, are arranged on the front side of the machine body and on the lower side of the engine 3, so that the balance between the front and the rear when the work device is connected to the rear part of the machine body The center of gravity of the airframe can be lowered while the engine 3 is disposed at a relatively high position, so that the stability of the airframe can be improved.

  As shown in FIGS. 6 and 15, the hydraulic oil tank 93 is between the left and right main frame members 94 in the machine body frame 1 and between the connecting frame members 95 before and after connecting the main frame members 94. It is received and supported by left and right metal fittings 96 that are bolted to the left and right main frame members 94.

  As shown in FIGS. 6 and 7, an air cleaner 98 is provided between the engine 3 and the steering post 97 erected at the rear thereof, making effective use of the space formed between them. Yes.

As shown in FIGS. 6 and 16, the lift cylinder 7, above the transmission case 4, is deployment in attitude down after along its upper surface, with a pair of left and right lift arms 8, is bolted to the transmission case 4 Thus, the shape and configuration of the mission case 4 can be simplified as compared to the case where the lift cylinder 7 is integrally provided in the mission case 4.

  Each of the left and right brackets 99 is configured such that its lower edge portion 100 is received and supported by the upper surface portion 101 of the mission case 4, whereby each bolt for connecting the left and right brackets 99 to the mission case 4. However, the possibility of shearing with a load of a working device or the like is avoided.

  Note that reference numeral 102 in FIG. 6 is a pair of left and right that suppresses adhesion of muddy water to the operation shafts 35, 38, 41, 44, 48, 79 equipped in the mission case 4 and the respective linkage mechanisms linked thereto. It is a muddy water cover.

[Another Example]
Other embodiments of the present invention will be listed below.

[1] As the transmission system 14, a shaft transmission type constituted by a transmission shaft and a bevel gear, a chain transmission type constituted by a transmission chain or the like may be adopted.

[2] The engine 3 is mounted with the output shaft 13 extending in the front-rear direction of the aircraft, and the mission case 4 is mounted with the input shaft 16 extending in the front-rear direction of the aircraft. The lateral one side on the floor surface 84 in the boarding step 10 so that the transmission system 14 bypasses the pedal operation unit 86 formed in the boarding step 10 over the output shaft 13 and the input shaft 16. You may make it carry out displacement deployment.

  In this case, the transmission system 14 includes a transmission shaft disposed in parallel to the output shaft 13 and the input shaft 16, a first lateral transmission shaft extending from the output shaft 13 to the transmission shaft, and a first transmission shaft extending from the transmission shaft to the input shaft 16. Two lateral transmission shafts, bevel gears that connect them so as to be able to transmit them, transmission shafts arranged parallel to the output shaft 13 and the input shaft 16, and transmission from the output shaft 13 to the transmission shaft It is conceivable to employ a belt-type transmission mechanism and a belt-type transmission mechanism that transmits power from the transmission shaft to the input shaft 16.

[3] As the auxiliary transmission system 66, a belt transmission type constituted by a transmission belt or a chain transmission type constituted by a transmission chain or the like may be adopted.

Overall left side view of the tractor Overall right side view of the tractor Overall view of the tractor Overall perspective view of tractor viewed from right front Overall perspective view of tractor viewed from left rear General left side view of tractor Perspective view of main parts showing arrangement of engine, transmission case, etc. Longitudinal rear view of the mission case Longitudinal rear view of the main part of the mission case Longitudinal side view of the mission case Development cross-sectional plan view of the main part of the mission case Plan view of the main part showing the shape of the guide groove of the main transmission lever A longitudinal rear view of the main part showing the seal structure for the support part of the output shaft for traveling in the transmission case Longitudinal rear view of main part showing support structure of auxiliary transmission system in mission case The perspective view of the principal part which shows arrangement | positioning and support structure of a hydraulic oil tank The perspective view of the principal part which shows arrangement | positioning and support structure of a lift cylinder and a lift arm

DESCRIPTION OF SYMBOLS 2 Boarding operation part 3 Engine 4 Mission case 10 Boarding step 13 Output shaft 14 Transmission system 16 Input shaft 18 Transmission device 20 Transmission device 22 Rear wheel differential device 24 Lock mechanism 25 Traveling output shaft 27 Traveling transmission system 32 Output unit 35 Transmission operation shaft 38 Transmission operation shaft 41 Transmission operation shaft 44 Operation shaft 50 Oil seal 51 Oil seal 59 Power take-off shaft 62 Transmission shaft 63 Transmission shaft 64 Transmission shaft 65 Transmission shaft 66 Auxiliary transmission system 70 Auxiliary transmission shaft
8 3 Transmission belt 84 Floor 86 Pedal operation section

Claims (7)

While deploying the engine on the front side of the boarding driver equipped with a boarding step and a driver seat, a mission case is deployed below the driver seat on the rear side of the boarding step,
Said engine and said transmission case and partitioned deployed in front and back of the boarding step, the engine height position of the output shaft, and said transmission case has a height position of the input shaft, each of said boarding Place it higher than the step height position ,
The transmission system extending from the output shaft to the input shaft was displaced to one lateral side on the floor surface in the boarding step so as to bypass the pedal operation unit formed in the boarding step in plan view . Deploy in state ,
The transmission system extending from the output shaft to the input shaft is bent in a dogleg shape so that the lower middle portion thereof is displaced downward so that the lower side portion of the transmission is in the front-rear direction along the floor surface in a side view. tractor you have. The output shaft and the input shaft are extended toward the left and right sides of the fuselage, and the transmission system is configured as a belt transmission type including a transmission belt extending between the extended ends of the output shaft and the input shaft. tractor according to claim 1 in Te. 3. The tractor according to claim 1, wherein the transmission case is formed such that an output unit including an output shaft for traveling is positioned at the lowest position . 4. A plurality of oil seals are juxtaposed between the transmission case and the output shaft for traveling, and an oil seal attached to the outermost position of the transmission case can be attached and detached from the outside of the transmission case. The tractor according to claim 3, which is configured as described above . A transmission gear for driving and a differential device for rear wheels incorporated in the transmission case, and an operating shaft of a lock mechanism that enables differential transmission between the transmission gear shifting shaft and the rear wheel differential gear; The tractor according to any one of claims 1 to 4, wherein the tractor is disposed above the mission case so as to be higher than a height position of the boarding step . The power transmission shaft is provided in the mission case, and an auxiliary transmission system extending from the input shaft to the power extraction shaft is disposed in the upper part of the transmission case. Tractor. The auxiliary transmission system is configured as a shaft transmission type including an auxiliary transmission shaft extending from the input shaft to the power take-off shaft, and the posture of the auxiliary transmission shaft is set to travel travel from the input shaft to the travel output shaft. The tractor according to claim 6, wherein the tractor is set in a posture that intersects with the posture of each transmission shaft of the system .

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