JP2010195095A - Working vehicle - Google Patents

Abstract

In the present invention, when a PTO clutch for switching power transmission between a rear PTO shaft and a mid PTO shaft is provided in a work case in a work vehicle, maintenance around the PTO clutch can be easily performed, and a rear PTO shaft is provided. And the operation system of the mid PTO axis is simplified.
In a work vehicle that drives the front and rear wheels by shifting the power of an engine in a transmission case, a PTO transmission shaft is extended to the rear side of the rear wheel drive shaft in the transmission case. In addition, a power transmission mechanism for the rear PTO shaft 11 and the mid PTO shaft 12 is provided at the rearmost portion of the transmission case 3 via the PTO clutch 150, and the rear portion of the transmission case 3 is released to allow inspection work around the PTO clutch 150. It is set as the structure of the work vehicle characterized by having comprised to.
[Selection] Figure 3

Description

  The present invention relates to a work vehicle. In particular, in a work vehicle such as a tractor or a passenger management machine, a rear output shaft (rear PTO shaft) with the power output shaft (PTO shaft) to the work machine directed toward the rear of the machine and a front output shaft (mid And a transmission case provided with a PTO shaft.

  Some tractors have a rear PTO shaft and a mid PTO shaft so that a rotary cultivator can be mounted on the rear PTO shaft and a lawn mower can be mounted on the mid PTO shaft. For example, in the tractor described in Japanese Patent Laid-Open No. 2006-11843, a rear PTO axis and a mid PTO axis are provided, and only the rear PTO axis or the mid PTO axis is driven or both the rear PTO axis and the mid PTO axis are driven. I can do it.

Japanese Patent Laid-Open No. 2006-11843

  In the tractor provided with the rear PTO shaft and the mid PTO shaft, the drive change of the rear PTO shaft and the mid PTO shaft is performed by switching the PTO clutch provided in the transmission case. Driving reaction force is applied, and maintenance such as replacement is necessary due to damage or wear of the PTO clutch. However, in the conventional configuration described in the above-mentioned Japanese Patent Application Laid-Open No. 2006-11843, the PTO clutch is located approximately at the center before and after the transmission case. Therefore, the maintenance work is performed by releasing a part of the mission case on the step floor of the tractor and under the cockpit, and the workability is poor and the maintenance is difficult.

  Therefore, an object of the present invention is to facilitate maintenance around the PTO clutch when a work vehicle is provided with a PTO clutch for switching the power transmission between the rear PTO shaft and the mid PTO shaft in the transmission case. .

The problems of the present invention are solved by the following means.
According to the first aspect of the present invention, in a work vehicle that drives the front and rear wheels by shifting the power of the engine (2) in the transmission case (3), the rear wheel drive shaft (5) in the transmission case (3) is used. In addition, the PTO transmission shaft (41) is extended to the rear side, and power is transmitted to the rear PTO shaft (11) and the mid PTO shaft (12) via the PTO clutch (150) at the rearmost portion of the transmission case (3). A working vehicle is provided, which has a mechanism and is configured such that the rear part of the transmission case (3) is released to enable inspection work around the PTO clutch (150).

  With this configuration, maintenance of the power transmission switching mechanism to the PTO clutch (150), the rear PTO shaft (11), and the mid PTO shaft (12) can be performed by releasing the rear portion of the transmission case (3).

  The invention described in claim 2 is configured such that the lever for turning on and off the power transmission to the rear PTO shaft (11) and the mid PTO shaft (12) is performed by a single PTO switching lever (149). The working vehicle according to claim 1, which is characterized by the above.

  The rear PTO shaft (11) and the mid PTO shaft (12) are turned on and off with a single PTO switching lever (149).

  According to the first aspect of the present invention, in the rear part of the work vehicle in which maintenance of the power transmission switching mechanism to the PTO clutch (150), the rear PTO shaft (11), and the mid PTO shaft (12) can be easily attached and detached, the transmission case (3 ) The rear part can be released, so the work is easy and efficient.

  According to the second aspect of the invention, in addition to the effect of the first aspect, the rear PTO shaft (11) and the mid PTO shaft (12) can be turned on and off with a single PTO switching lever (149). Since the operation is easy and the number of levers is reduced, the structure is simple and inexpensive.

It is a whole side view of an Example work vehicle (tractor). It is a whole top view of an Example working vehicle. It is side sectional drawing of the mission case of an Example working vehicle. It is a partially expanded side sectional view in a mission case. It is an expanded side sectional view which shows the cut state of a PTO clutch. It is an expanded sectional side view of the PTO clutch which shows the drive state of a mid PTO shaft. It is an expanded sectional side view of the PTO clutch which shows the drive state of a rear PTO shaft. It is an expanded sectional side view of the PTO clutch which shows the state which drives a mid PTO axis | shaft and a rear PTO axis | shaft together. It is an expanded sectional side view of the PTO clutch which shows the drive state of the mid PTO shaft of another Example. It is an expanded sectional side view of the PTO clutch which shows the drive state of the rear PTO shaft of another Example. It is an expanded sectional side view of the PTO clutch which shows the state which drives the mid PTO axis | shaft and rear PTO axis | shaft of another Example together. It is an expanded sectional side view of the PTO clutch of another Example which shows the disconnection state of a PTO clutch. 1 is an overall side cross-sectional view of a transmission case equipped with a hydraulic continuously variable transmission. It is a partial enlarged side view of a work vehicle using a transmission case with a hydraulic continuously variable transmission. It is a partial expanded side view of a hydraulic continuously variable transmission. It is a side view of the cam plate of the mission case. It is a partial enlarged side view of a work vehicle using a transmission case with a hydraulic continuously variable transmission. It is a partial enlarged plan view of a work vehicle using a mission case with a hydraulic continuously variable transmission. It is a partial enlarged plan view of a work vehicle. It is a partial enlarged side view of a work vehicle.

Embodiments of the present invention will be described below based on the embodiments shown in the drawings.
1 and 2 are general views of a tractor shown as an example of a working vehicle in the present invention. The power of an engine 2 mounted in a bonnet 1 at the front of the airframe is appropriately shifted in a transmission case 3 before The front wheel 6 is driven by the steering wheel 8 that is transmitted to the wheel shaft 4 and the rear wheel shaft 5 to drive both the front wheel 6 and the rear wheel 7 or only the rear wheel 7 and is seated on the seat 10 provided on the fuselage. Run while steering No. 6. A work machine such as a rotary cultivator is mounted on the hitch 9 projecting rearward of the machine body, and the work machine mounted on the hitch 9 is driven by the rear PTO shaft 11 projecting rearward from the mission case 3. A working machine such as a lawn mower mounted between the front wheel 6 and the rear wheel 7 is driven by a mid PTO shaft 12 protruding forward from the rear part.

  FIG. 3 is a cross-sectional view of the power transmission mechanism. A main output shaft 18 protruding rearward from the engine side case 13 and an input shaft 20 protruding forward from the transmission case 3 are connected by a joint 19, and the upper side is connected by a connecting cover 21. Covering.

  Inside the engine side case 13, the power of the engine 2 is transmitted to the first output shaft 15 so as to be intermittently connected by the main clutch 14, and is slightly decelerated by the first gear 16 and the second gear 17 and transmitted to the main output shaft 18. ing.

The mission case 3 is configured by integrally connecting three hollow cases of a front case 36, a mid case 37, and a rear case 45 from the front.
In the front case 36, the rotation of the input shaft 20 is transmitted to the first transmission shaft 25 by the third gear 22 and the fourth gear 23.

  In the mid case 37, the rotation of the first transmission shaft 25 is directly transmitted to the PTO transmission shaft 41 by the second joint 40, and further, the first transmission gear 27 and the second transmission gear 29 fixed to the first transmission shaft 25. A fourth transmission gear 26, a fifth transmission gear 28, a sixth transmission gear 30, and a reverse gear 50 (the reverse gear 50 is a gear not shown in the figure and is a first transmission gear) fitted to a travel shaft 24 with which the third transmission gear 31 is engaged. 27 is engaged with the shaft by the key shift clutch 46, and is shifted from the first speed to the third speed and reversely rotated to be transmitted to the traveling shaft 24.

  The rotation of the travel shaft 24 is transmitted to the large gear portion 59 of the gear cylinder 69 loosely fitted to the first transmission shaft 25 by the fourteenth gear 57, and the high and low clutch gear 32 that is spline-fitted to the bevel gear shaft 121 is the fourteenth. By meshing with the gear 57 or meshing with the small gear portion 68 of the gear cylinder 69, the bevel gear shaft 121 is shifted at a high and low speed, and the rotation of the bevel gear shaft 121 is transmitted to the rear wheel shaft 5 by the bevel gear 38 and the axle bevel gear 39. Further, the fifteenth gear 122, the fifth gear 33, and the clutch gear 34 that are spline-fitted to the bevel gear shaft 121 are transmitted to the front wheel drive shaft 35, and the front wheel shaft 4 is driven by the front wheel drive shaft 35.

The rotation of the PTO transmission shaft 41 is transmitted to the transmission portions of the rear PTO shaft 11 and the mid PTO shaft 12 provided on the rear side of the rear wheel shaft 5.
The tenth gear 55 is spline fitted to the PTO transmission shaft 41 and the first counter gear 42 is loosely fitted, and the eleventh gear 48 is spline fitted to the rear PTO shaft 11 and the first clutch gear 56 is loosely fitted. The PTO clutch gear 43 is loosely fitted to the first clutch gear 56, and the twelfth gear 58 is splined. A constant mesh clutch switching gear 47 that is always meshed with the eleventh gear 48 and meshed appropriately with the first clutch gear 56 and the PTO clutch gear 43 is externally fitted. The second clutch gear 43, the eleventh gear 48, and the clutch switching gear 47 constitute a PTO clutch 150, and the PTO clutch 150 is shifted by a single PTO switching lever 149 provided near the seat 10.

  The tenth gear 55 is meshed with the twelfth gear 58 and the first clutch gear 56 is always rotating. The state shown in FIG. 5 is the first clutch gear 56 and the clutch switching gear 47 is not meshed with the rear PTO shaft 11 and the mid PTO. In the state where the shaft 12 is not driven together, the clutch switching of the PTO clutch 150 is performed as follows.

When the clutch switching gear 47 is slid to mesh with the eleventh gear 48 and the first clutch gear 56, the rear PTO shaft 11 is driven. (Fig. 7)
When the clutch switching gear 47 is separated from the eleventh gear 48 and slid so as to mesh with the first clutch gear 56 and the PTO clutch gear 43, the rotation of the first clutch gear 56 changes from the PTO clutch gear 43 to the first counter gear 42. The mid PTO shaft 12 is driven by transmission described later. (Fig. 6)
When the clutch switching gear 47 is slid to mesh with the three gears of the eleventh gear 48, the first clutch gear 56, and the PTO clutch gear 43, the rear PTO shaft 11 and the mid PTO shaft 12 are driven together. (Fig. 8)
The first counter gear 42 rotates through the second counter gear 49 of the first counter shaft 50, the third counter gear 44 of the second counter shaft 51, and the fourth counter gear 52 of the third counter shaft 53. The mid PTO shaft 12 is driven by being transmitted to a thirteenth gear 54 formed on the motor 12.

  In the embodiment shown in FIGS. 9 to 11, no blank is provided on the internal teeth of the clutch switching gear 47, FIG. 9 shows the driving state of only the mid PTO shaft 12, and FIG. 10 shows the rear PTO shaft 11 and the mid PTO shaft 12. In a state where both are driven, FIG. 11 shows a state where only the rear PTO shaft 11 is driven, and when the clutch switching gear 47 is further moved to the right to disengage the first clutch gear 56, the rear PTO shaft 11 and the mid PTO Both shafts 12 are not driven.

  FIG. 12 shows another configuration for driving switching between the rear PTO shaft 11 and the mid PTO shaft 12. The first gear portion 60 and the second gear portion 61 are formed on the PTO transmission shaft 41, and a sixth counter for the mid PTO shaft 12 is formed. A fifth counter gear 66 meshing with the gear 67 is loosely fitted, and a clutch gear 64 having a large gear portion 62 and a small gear portion 63 formed on the rear PTO shaft 11 is spline-fitted so as to be shiftable by a shifter 65.

  In this configuration, when the small gear portion 63 is engaged with the first gear portion 60, only the rear PTO shaft 11 is driven, and when the clutch gear 64 is removed from both the first gear portion 60 and the second gear portion 61, the rear PTO shaft is driven. 11 and the mid PTO shaft 12 are not driven, and when the sixth counter gear 67 is engaged with the second gear portion 61 and the fifth counter gear 66, both the rear PTO shaft 11 and the mid PTO shaft 12 are driven. become.

FIG. 13 shows an embodiment of a mission case of a work vehicle equipped with a hydraulic continuously variable transmission (hereinafter referred to as HST) 80.
An output shaft 77 projecting rearward from the engine side case 70 and an input shaft 79 projecting forward from the HST 80 attached to the transmission case 75 are connected by a joint 78 with a fan, and the upper side is covered with a connecting cover 76.

The mission case 75 is configured by integrally connecting three hollow cases of a front case 71, a mid case 72, and a rear case 73 from the front.
The first output shaft 81 of the HST 80 attached to the front case 71 outputs to the PTO drive system, and the second output shaft 74 outputs to the travel drive system.

  The rotation of the first output shaft 81 is transmitted to the first PTO shaft 83 via the first clutch 82, and from the first gear 84 to the second counter gear 85, the third counter gear 86, the fourth counter gear 87, and the clutch gear. The transmission branches from the third counter gear 86 to the transmission for driving the second PTO shaft 91 by the second clutch 89. The second PTO shaft 91 drives the rear PTO shaft 94 via the first PTO gear 92 and the second PTO gear 93.

  The rotation of the second output shaft 74 is transmitted from the first travel gear 95 to the second travel gear 96 of the first travel shaft 97, and a three-stage gear provided between the second travel gear 96 and the third travel shaft 99. The third travel shaft 99 is driven by the speed change mechanism 98, and the rear wheel drive shaft 101 is further driven by the first bevel gear 105 and the second bevel gear 100. The rotation of the third travel shaft 99 drives the front wheel drive shaft 106 from the third travel gear 102 via the fourth counter gear 103 and the third clutch gear 104.

  FIG. 14 is a side view of the step portion of the cockpit of the work vehicle. The forward pedal 115 and the reverse pedal 116 are connected to the pivot shaft 119 provided on the cover 76, and the depressing operation of the forward pedal 115 and the reverse pedal 116 is armed. 117 and the link 118 are transmitted to the cam plate 108 fixed to the trunnion shaft 107 which is the transmission shaft of the HST 80, and when the forward pedal 115 is depressed, the trunnion shaft 107 is rotated forward, and when the reverse pedal 116 is depressed, the trunnion shaft 107 is rotated backward.

  A cam recess 114 is formed in the cam plate 108 on the opposite side of the trunnion shaft 107 from the attachment portion of the link 118, and a roller 110 pivotally supported at one end of the one piece 109 a of the L-shaped arm 109 is inserted into the cam recess 114. The trunnion shaft 107 is returned to neutrality by being urged by a neutral spring 120 hooked on the other piece 109b so as to drop into the center.

  And the wire 111 connected with the governor of the engine 2 is connected via the tension spring 112 at the front end side of the other piece 109b of the L-shaped arm 109. The connection between the other piece 109b and the tension spring 112 enables the pulling adjustment of the wire 111 by changing the hole 113 engaged with the plurality of holes 113.

  When the forward pedal 115 and the reverse pedal 116 are stepped on, the cam plate 108 rotates in the opposite direction and rotates the trunnion shaft 107 to drive the machine forward or backward. The cam recess 114 pushes out the roller 110. The wire 111 is pulled and the rotation of the engine 2 is increased.

  FIG. 16 is an enlarged view of the cam plate 108. The position where the roller 110 falls and the cam recess 114 is stabilized corresponds to the characteristic that the neutral orifice of the HST 80 is located on the reverse side, with the trunnion shaft 107 slightly located on the reverse side. This makes neutral adjustment easy. In addition, when the vehicle starts moving forward and backward, the cam recess 114 pushes out the roller 110, and the starting contact S at which the airframe starts moving has a smooth convex curved surface, thereby reducing the stepping force of the forward pedal 115 and the reverse pedal 116 at the time of starting. . Further, the forward pedal 115 and the reverse drive are moved backward by making the inclination of the medium speed contact area A where the roller 110 is in contact from the neutral speed to the medium speed steep and decreasing the inclination of the high speed contact area B where the roller 110 is in contact from the medium speed to the high speed. The pedal 116 can be easily returned from the middle speed to the neutral speed, and the depression resistance of the forward pedal 115 and the reverse pedal 116 from the medium speed to the high speed is softened. It should be noted that the contact area length of the roller 110 during forward movement and the contact area length of the roller 110 during backward movement are appropriately changed so that the engine 2 reaches the maximum rotation speed at the maximum forward / rearward speed according to the difference in the interlocking mechanism. You may do it.

17 and 18 show the installation of the brake pedal 125. FIG.
An arm support cylinder 123 having a brake arm 126 fixed to a brake pedal 125 is pivotally supported on a horizontal shaft 127 that is horizontally mounted on the floor frame of the airframe, and an action arm 128 is provided on the arm support cylinder 123 so as to project downward. Stop arm 129 is projected.

  Three members of a tension spring 131 provided between the mounting bracket 135 of the brake rod 133, the auto cruise return cable 134 and the mounting pin 132 are connected to the distal end portion of the action arm 128 by a connecting pin 124.

The stop arm 129 abuts on a stop bolt 130 attached to the floor frame to determine the depression limit of the brake pedal 125.
As shown in FIG. 19, the horizontal shaft 127 to which the arm support cylinder 123 to which the brake arm 126 of the brake pedal 125 is fixed is provided penetrating a handle post 137 standing at the center of the left and right of the machine body, and the horizontal shaft 127 is rotated. In order to operate the brakes provided at the rear of the aircraft, the linkage is linked. A parking brake arm 136 holds the brake in an operating state. Then, a right-side mounting brake member (brake pedal, brake arm, arm support cylinder, and parking brake arm) and a left-side mounting brake member (left brake pedal 125L, left brake arm 126L, left arm support cylinder 123L, and left parking brake arm) The right brake specification and left brake specification can be created at a lower cost by adding more common parts.

  In FIG. 20, a mower 145 is attached to the bottom of the work vehicle with a mower link 147 so that power is transmitted from the mid PTO shaft 90 to the mower gear case 141 by the two universal joints 142 and 148 and the mower drive shaft 140. It is a configuration. The mower drive shaft 140 is covered with a boot-shaped shaft 144 so that the rotating portion is not exposed to the outside. The mower 145 side universal joint 142 of the mower drive shaft 140 is attached to the mower exterior case with bolts and nuts. Further, the metal shaft cover 146 further covers the mower exterior case together with the cutout portion on the mower drive shaft 140 side. Note that the mid PTO shaft 90 side universal joint 148 of the mower drive shaft 140 may also be covered with a metal cover attached to the transmission case 75. In addition, a sensor for detecting the movement of the mower link 147 is provided so that when the mower 145 is raised, the rotation of the mid PTO shaft 90 is stopped to ensure safety.

2 Engine 3 Mission case 5 Rear wheel shaft 11 Rear PTO shaft 12 Mid PTO shaft 41 PTO transmission shaft 149 PTO switching lever 150 PTO clutch

Claims (2)

  In a working vehicle that drives the front and rear wheels by shifting the power of the engine (2) in the transmission case (3), the PTO transmission shaft (41) extends further to the rear side than the rear wheel drive shaft (5) in the transmission case (3). ) And a power transmission mechanism to the rear PTO shaft (11) and the mid PTO shaft (12) via the PTO clutch (150) at the rearmost portion of the transmission case (3). ) A work vehicle characterized in that the rear part of the PTO clutch (150) can be inspected by releasing the rear part.   The lever for turning on and off the power transmission to the rear PTO shaft (11) and the mid PTO shaft (12) is configured to be performed by a single PTO switching lever (149). Work vehicle.

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