JPH0219353Y2 - - Google Patents

Description

[Detailed description of the invention] This invention includes an engine at the front of the fuselage and a transmission case at the rear, and a main shaft for power transmission extending from the engine to the transmission case. This relates to an agricultural tractor in which a seat is arranged above the transmission case, and was proposed for the purpose of providing a relatively small agricultural tractor that is easy to get on and off from and drive.

Conventionally, in relatively small agricultural tractors,
Steps are installed at the bottom of both left and right sides of the housing that connects the engine and the transmission case, and of the transmission case that is directly connected to the engine. In many cases, a gear shift lever provided for traveling is operated, and it is difficult to get on and off the vehicle by climbing over the transmission case where the gear shift lever has shifted. It was also difficult to shift gears between the legs.

The present invention was developed to solve these problems with conventional machines, and its features include the operation shaft of the driving transmission mechanism, the operation shaft of the forward/reverse switching mechanism, and the front wheel drive switching mechanism. operating axis,
and the operation shafts of the PTO transmission mechanism are all protruded and supported on the side surface of the transmission case, and a lever support shaft is provided near the bottom of the seat, and the lever support shaft can support the operation lever for the operation shaft. In this case, the lever support shaft and the operating shaft are connected to each other, and a flat operating step is provided along the upper surface of the mission case over the entire left and right width.

The effects of the above configuration are as follows.

All of the transmission shafts for travel transmission and other operating systems are located on the side of the transmission case, and these transmission shafts are linked to the lever support shaft installed near the bottom of the seat, so the transmission case can be mounted on the top of the transmission case. There are no obstacles when installing the steps on the machine, and the steps can be placed close enough to the top of the mission case.As a result, you can get on and off easily using the flat left and right steps with no protruding levers, and the lever support Since the shaft is located near the bottom of the seat, all the control levers for each transmission mechanism can be placed near the seat, making it possible to compactly organize the operation systems for each transmission mechanism and improve operating moderation. Moreover, it is now possible to drive comfortably while seated in the seat by operating the lever on the side where hands tend to bend.

Hereinafter, embodiments of the present invention will be described based on the drawings.

Fig. 1 shows the entire agricultural tractor according to the present invention, in which an engine 2 and a transmission case 3 are connected to the front and rear of a main frame 1, and a main clutch housing 4 directly connected to the rear of the engine is connected to the transmission case 3.
Power is transmitted through the shaft. Steering front wheels 5, 5, which are driven by receiving power from the transmission case 3, are supported below the front of the main frame 1, and rear wheels 6, 6 are mounted on drive shafts on both left and right sides of the transmission case 3. The rear part of the transmission case 3 is equipped with hydraulically driven lift arms 7, 7 for lifting and lowering the work equipment.
A PTO shaft 8 is provided to protrude rearward.

Figures 2 to 4 show the mission case 3.
The mission structure of is shown.

This transmission structure incorporates a main transmission mechanism 9 for driving, an auxiliary transmission mechanism 10, a super reduction mechanism 11, a front/rear switching mechanism 12, a rear wheel differential mechanism 13, a front wheel drive switching mechanism 14, and a PTO transmission mechanism 15. Each mechanism will be explained in detail below.

( ): Main transmission mechanism 9 An input shaft 17 connected to a main shaft 16 led out from the main clutch housing 4 is protruded from the upper front surface of the transmission case 3. The shaft 18 is interlocked and connected by gears G ₁ and G ₂ . A second speed change shaft 19 is disposed below the first speed change shaft 18, and has gears meshing with gears G ₂ , G ₃ , and G ₄ fixedly attached to the first speed change shaft 18 .
G ₅ , G ₆ , and G ₇ are loosely fitted to the second speed change shaft 19, respectively. In addition, the second gear shift shaft 19 has a gear G ₇ and a shaft 1.
a first shift sleeve _{S 1 that} selectively connects and disconnects gear G 6 or G 5 and shaft 19 through a spline collar C 1; and a second shift sleeve S 1 that selectively connects and disconnects gear G ₆ or G ₅ and shaft 19 through a spline collar C ₂ . Sleeve S ₂ is installed, and by shifting the first sleeve S ₁ to the left and connecting gear G ₇ to shaft 19, the first speed is set, and by shifting the second sleeve S ₂ to the right, gear G ₆ is set. Axis 19
By connecting the gear G5 to the shaft 19, a second speed can be obtained, and by shifting the second sleeve _S2 to the left and connecting the gear _G5 to the shaft 19, a third speed can be obtained.

(): Forward/forward switching mechanism 12 A third speed change shaft 20 is provided concentrically at the rear of the second speed change shaft 19, and a third speed change shaft 20 is attached to the front end of the shaft 20.
A forward transmission state is obtained by shifting the shift sleeve S ₃ to the left to directly connect the spline collar C ₃ of the second transmission shaft 19 with the spline collar C ₄ of the third transmission shaft 20, and the third transmission state is obtained. By shifting the shift sleeve S ₃ to the right and directly connecting the gear G ₈ loosely fitted to the third transmission shaft 20 with the shaft 20, a reverse transmission state is obtained. In other words, the second
A gear G ₉ fixed to the rear of the transmission shaft 19 is engaged with an idle gear G ₁₀ loosely fitted to the pack shaft 21, and a cylinder loosely fitted to the front wheel transmission shaft 22 supported at the bottom of the transmission case 3. Front gear of shaft 23
G ₁₁ and the idle gear G ₁₀ are engaged, and
The rear gear G ₁₂ of the cylindrical shaft 23 is engaged with the idling gear G ₈ of the third speed change shaft 20, and the third speed change shaft 20 is driven in reverse by the transmission via the cylindrical shaft 23. It's becoming like that.

(): Sub-transmission mechanism 10 The third transmission shaft 20 has a pair of large and small gears G ₁₃ , G ₁₄
is fixedly installed, and gears G ₁₅ and G ₁₆ that mesh with the gears G ₁₃ and G ₁₄ are loosely fitted to the final transmission shaft 24 arranged above the shaft 20, and
A fourth shift sleeve S4 is provided for selectively uncoupling both gears _G15 and _G16 from the shaft 24 via a spline collar _C5 , and this shift sleeve _S4 is shifted to the left to shift to a low- _speed transmission state. Shift to the right to obtain a high-speed transmission state.

(): Super deceleration mechanism 11 Opening 2 formed on the left side of the transmission case 3
5 has a bearing bracket 26 that can be attached and detached from the outside.
is attached to the bracket 26, and large and small gears G ₁₇ and G ₁₈ are integrated and supported with a loose fit on this bracket 26 via a support shaft 27 so as to be freely shiftable. On the other hand, the large gear G ₁₆ of the auxiliary transmission mechanism 10 is integrally connected with a wide small gear G ₁₉ that is always engaged with the large gear G ₁₇ , and the final speed change shaft 24 is connected to the small gear G ₁₈ . An articulating gear G ₂₀ is fixed. Then, with the auxiliary transmission mechanism 10 in neutral, the large and small shift gears G ₁₇ and G ₁₈ are shifted to the left in the figure, and the small gear G ₁₈ is engaged with the gear G ₂₀ , thereby shifting the final shift shaft 2.
4 can be driven with a large deceleration.

( ): Front wheel drive switching mechanism 14 A front wheel drive gear G 22 is integrally connected to the gear G ₂₀ of the super reduction mechanism 11, and _a gear meshing with this gear G ₂₃ is connected to the third speed change shaft 20. G ₂₄ and gear G ₂₅ integrated therewith are loosely supported. Further, a shift gear G ₂₆ that can freely engage with the idle gear G ₂₅ is spline-fitted to the rear of the front wheel transmission shaft 22, and the transmission shaft 22 can be driven and stopped by shifting this gear G ₂₅ . ing.

(): PTO transmission mechanism 15 A PTO system first transmission shaft 36 is provided behind the input shaft 17, and a gear G ₂₇ is freely rotatably attached to the rear of this shaft 36 and is fixedly attached to the first transmission shaft 17. gear
G ₂₈ is permanently occluded. In addition, the first transmission shaft 36
A shift gear G ₂₉ spline-fitted to the main transmission mechanism 9 can freely engage with the outer periphery of the boss of the idling gear G ₂₇ .
It is provided so that it can freely engage with the gear G ₃ of the input shaft 17 and can freely engage with the outer periphery of the rear end of the input shaft 17, and by shifting this shaft gear G ₂₉ to the right, the transmission shaft 36 is driven at a low speed or to the left. It is configured so that it can be driven at medium speed by shifting, and can be driven at high speed at the same speed as the input shaft 17 by further shifting to the left. Further, the rear end of the first transmission shaft 36 is connected to the second transmission shaft 36 via an interlocking clutch type torque miller 37.
The transmission shaft 38 and the PTO shaft 8 are interlocked for deceleration via a gear reduction mechanism (not shown).

Next, the operating structure of each mechanism will be explained.

As shown in FIG. 7, a shift fork 4 that operates two shift sleeves S ₁ and S ₂ of the main transmission mechanism 9
0 and 41 are slidably supported on a common fixed support shaft 42, and cam followers 43 and 44 each consisting of a rotating roller are mounted facing outward from the case. A large opening 45 is formed in the left side wall of the mission case 3, and a cover 46 covers it.
A disc-shaped rotary cam 48 having a cam groove 47 formed on its side surface into which the cam followers 43 and 44 engage is pivotally supported. Further, the cover 46 supports an operating shaft 49 which is rotatably operated from the outside, and this shaft 43 and a support shaft 50 of the rotary cam 48 are moved at increased speed by gears 51 and 52. An arm 5 attached to the outer end of the operating shaft 49
3 shows the cam groove 47 in FIG. 6 so that the first speed is at the _P1 position, the second speed is at the _P2 position, the _third speed is at the P3 position, and neutral is obtained at each N position. The shape is set. Further, a lever support shaft 55 is horizontally fixed to a frame 54 attached above the transmission case 3, and a main shift lever 56 supported on the left end of this shaft and the arm 53 are linked by a rod 57, and the main shift lever 55 is It is configured to perform three main gear shifting operations by linearly swinging the lever 56 back and forth.

As shown in FIG. 10, a shift fork 6 that operates the shift sleeve S ₄ of the sub-transmission mechanism 10
0 is a bearing bracket 26 installed to cover an opening 25 formed on the left side of the transmission case 3.
The shift fork 64 that operates the shift gears G ₁₇ and G ₁₆ of the super reduction mechanism 11 is also slidably supported on another fixed support shaft 65 of the bracket 26. and engaging portions 60a, 64 connected to the bases of both forks 60, 64.
a are arranged side by side on the left and right. Further, the bracket 26 includes an arm 6 which is selectively engaged with the engaging portions 60a and 64a by left and right shifting.
6 is supported so as to be able to shift left and right and rotate freely. An operating arm 68 is fixed to the outer end of the operating shaft 67, and an L-shaped link 69 that engages with a base extension 68a of the arm 68 is pivotally connected to a bracket 70 fixed to the cover 62. , the operating shaft 67 is shifted left and right by the swinging of the link 69.

Further, a lever mounting member 73 is rotatably attached to the lever support shaft 55 and supports a shift lever 71 for sub-shifting and super deceleration so as to be swingable from side to side around a fulcrum 72. The arm 68 is linked to the arm 68 by a rod 74. Moreover, the support shaft 5
A grooved shift sleeve 76 that is biased to shift to one side by a spring 75 is fitted onto the outer circumference of the shift sleeve 76 , and the outer peripheral groove of this sleeve 76 is connected to the tip arm 71 of the shift lever 71 .
is engaged with a. Further, a bell crank arm 77 that engages with the sleeve 76 is pivotally connected to a fixed bearing bracket 78 so as to be able to swing around a fulcrum 79, and the other end of the bell crank arm 77 is connected to the link 69 via a rod 80. It is linked. The spring 75 applies a biasing force to the sleeve 76 in the direction of pulling and shifting the operating shaft 67 outward, that is, so that the arm 66 acts on the engaging portion 60a of the sub-shift fork 60.

Therefore, by swinging the gear shift lever 71 back and forth in the illustrated state, only the shift fork 60 is operated back and forth to change the height of the sub-transmission mechanism 10, and the lever 71 is swung laterally at the neutral position in the middle of the operation path. Then, by shifting the sleeve 76 against the spring 75, the operating shaft 67 is pushed inward and the arm 66
is engaged with the engaging portion 64a of the shift fork 64, and then the shift lever 71 is swung downward to effect super deceleration.

A shift fork 85 that operates the shift sleeve S ₃ of the forward/reverse switching mechanism 12 and a shift fork 86 that operates the shift gear G ₂₆ of the front wheel transmission switching mechanism 14 slide on a common support shaft 87 fixed to the transmission case 3. Each shift fork 85, 86 has an operating arm 88, which is movably mounted and has the same shape.
89 are engaged with each other, and the operating shafts 90 and 91 of the operating arms 88 and 89 are supported through the left side wall of the mission case 3, and the operating shaft 90 for forward and backward switching is connected to the post 93 of the operating handle 92. An operating shaft 91 for switching front wheel drive is linked via a rod 96 to an operating lever 95 attached to the lever support shaft 55.

Further, an operating shaft 98 of a shift fork 97 that operates the shift gear G ₂₈ of the PTO transmission mechanism 15 is supported through the right side of the transmission case 3, and is rod-mounted to a shift lever 99 attached to the right end of the lever support shaft 55. 100.

A flat operating step 101 is provided at approximately the same level as the front upper surface of the transmission case 3 and extends across the entire left and right width, and the sub-shift lever 95,
Also, the PTO shift lever 99 is the left and right Fender 5
It is arranged around the feet of the seats 102 provided in the 8th room.

[Brief explanation of the drawing]

The drawings show an embodiment of the agricultural tractor according to the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a longitudinal side view of the transmission case, Fig. 3 is an expanded side view of the reverse transmission system, and Fig. 4 is a side view of the transmission case. Plan view of sub-transmission/super reduction mechanism section,
Fig. 5 is a front view of the control section, Fig. 6 is a side view of the control section, Fig. 7 is a front view of the main shift operation section, Fig. 8 is a sectional view taken along the - line in Fig. 7, and Fig. 9 is a side view of the control section. FIG. 10 is a front view showing the auxiliary transmission/super deceleration and PTO transmission operation parts, and FIG. 11 is a side view of the auxiliary transmission/super deceleration operation part. 2... Engine, 3... Mission case, 9
...Main transmission mechanism, 10...Sub-transmission mechanism, 11...
Super reduction mechanism, 12... Forward/forward switching mechanism, 14...
...Front wheel drive switching mechanism, 16... Main shaft, 49, 6
7, 90, 91, 98...operation shaft, 55...lever support shaft, 101...control step, 102...seat.

Claims (1)

[Scope of utility model registration request] An engine 2 is provided at the front of the fuselage, and a transmission case 3 is provided at the rear. A main shaft 16 for power transmission extends from the engine 2 toward the transmission case 3, and is provided above the transmission case 3. It is an agricultural tractor in which a seat 102 is arranged at a position, and the operating shafts 49, 67 of the traveling transmission mechanisms 9, 10, 11, the operating shaft 90 of the forward/reverse switching mechanism 12, and the operating shaft of the front wheel drive switching mechanism 14. 91 and the operation shaft 98 of the PTO transmission mechanism 15 are all supported by projecting on the side surface of the transmission case 3,
A lever support shaft 55 is provided near the bottom of the seat 102, and the operation shafts 49, 6 are attached to this lever support shaft 55.
The lever support shaft 55 and the operating shafts 49, 67, 90, 91, 98 are linked to each other so that the operating levers for the missions 7, 90, 91, 98 can be supported, and the upper surface of the mission case 3 is This agricultural tractor is provided with a flat steering step 101 along the entire width of the left and right sides.