Work vehicles

Abstract

To enable the speed of the rotation of an output shaft to be changed by effectively utilizing a space.SOLUTION: A work vehicle (1) comprises: a first output shaft (141) which can output the power of an engine (E); a second output shaft (146) which can output the power of the engine (E) to a position different from the first output shaft (141); and an output change gear (132) which is arranged on the engine (E) side with respect to a branch position (142) of the first output shaft (141) and the second output shaft (146). Consequently, the speed of the rotation of the output shaft can be changed by effectively utilizing a space in comparison to a case where the output change gear (132) is installed in the rear portion of a travel vehicle body (1a) with many restrictions on the space.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to work vehicles such as tractors, lawn mowers, and snow removal vehicles.

Background Art

[0002] In work vehicles such as tractors, lawn mowers, and snow removal vehicles, a configuration is known in which power from the engine of the traveling vehicle body can be transmitted not only to the rear rear PTO shaft (first output shaft) but also to the lower or front mid PTO shaft (second output shaft) (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=三十五]]In the conventional technology described in Patent Document 1, a PTO clutch (150) is provided at the branch position of the rear PTO shaft (11) and the mid PTO shaft (12), and the PTO clutch (150) controls the transmission of power to the rear PTO shaft (11) and the mid PTO shaft (12). That is, the PTO clutch (150) controls the engagement and disengagement of power transmission to the rear PTO shaft (11) and the mid PTO shaft (12). The configuration described in Patent Document 1 can engage and disengage power to the rear PTO shaft (11) and the mid PTO shaft (12), but does not have a transmission for changing the rotational speed of the rear PTO shaft (11) and the mid PTO shaft (12). Therefore, other than changing the engine speed, it is structurally impossible to change the speed of the rear PTO shaft (11) or the mid PTO shaft (12).

[0005] Therefore, to change the rotational speed of the rear PTO shaft (11) and the mid PTO shaft (12), the engine speed must be changed. However, changing the engine speed may cause the vehicle speed to fluctuate or the engine torque to be insufficient, which may affect the vehicle's operation during work. The implements mounted on work vehicles are diverse, and the required rotational speed and torque may differ depending on the type of implement. Therefore, it is conceivable to install a PTO transmission in the power transmission mechanism that transmits engine power to the PTO shaft. However, in small work vehicles, there are space constraints at the rear, making it difficult to install a transmission.

[0006] The technical challenge of this invention is to enable variable speed control of the output shaft rotation while making effective use of space. [Means for solving the problem]

[0007] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 comprises a vehicle body (1a) having an engine (E), a rear PTO shaft (141) capable of outputting power from the engine (E), a mid-PTO shaft (146) branching off from the transmission path of the rear PTO shaft (141) and capable of outputting power from the engine (E) to a position different from the rear PTO shaft (141), an output transmission (132) capable of changing the rotational speed of the rear PTO shaft (141) and the mid-PTO shaft (146), and a main transmission (102) that changes the speed of the power transmitted from the engine (E) to the rear wheels (3). A hydraulic clutch (131) for switching power transmission to the rear PTO shaft (141) and the mid PTO shaft (146), a rear PTO clutch (137) for switching power transmission to the rear PTO shaft (141), and a mid PTO clutch (144) for switching power transmission to the mid PTO shaft (146), The output transmission (132) is positioned on the engine (E) side of the branching point (142) between the rear PTO shaft (141) and the mid PTO shaft (146), and behind the main transmission (102). The rear PTO clutch (137) is located adjacent to the branching position (142) and is positioned closer to the rear PTO shaft (141) than the branching position (142), and the mid PTO clutch (144) is located on the mid PTO shaft (146). This is a work vehicle (1) characterized by the following:

[0008] The invention described in claim 2 is ,before When the output transmission (132) shifts the power of the engine (E) to a predetermined high rotational speed and the rotational speed of the engine (E) reaches the predetermined rotational speed, Hydraulic Control unit (210) that disengages the clutch (131) )of The work vehicle (1) described in claim 1 is characterized by being equipped with the following.

[0009] The invention described in claim 3 is a work vehicle (1) according to claim 1 or 2, characterized in that it comprises a rotation speed display unit (152) for displaying the rotation speed of an engine (E), the rotation speed display unit (152) having a first display unit (152a) positioned at a location that serves as an estimate of the engine rotation speed when the output transmission (132) is set to the high rotation side during operation, and a second display unit (152b) positioned at a location that serves as an estimate of the engine rotation speed when the output transmission (132) is set to the low rotation side during operation.

[0010] The invention described in claim 4 is, The main transmission (102) is equipped with a sub-transmission (113) that changes the speed of the power output from the main transmission (102), and the output transmission (132) is positioned between the main transmission (102) and the sub-transmission (113) in the longitudinal direction. Characterized by Claim 1 This is the work vehicle (1) described in [reference]. [Effects of the Invention]

[0011] According to the invention described in claim 1, Rear PTO Axis (141) and Mid PTO It is equipped with an output transmission (132) located on the engine (E) side of the branching point (142) with the shaft (146). The output transmission (132) is positioned behind the main transmission (102). This allows for more efficient use of space and enables the rotation of the output shaft to be changed compared to the case where the output transmission (132) is installed at the rear of the vehicle body (1a), which has many space constraints. According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, the clutch (131) is disengaged when the output transmission (132) shifts the power of the engine (E) to a predetermined high rotational speed and the rotational speed of the engine (E) reaches the predetermined rotational speed, thereby suppressing damage to the work equipment compared to when the clutch is not disengaged.

[0012] According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or 2, the user can easily understand the approximate engine speed by checking each display unit (152a, 152b), thereby improving work efficiency. According to the invention described in claim 4, Claim 1 In addition to the effects of the described invention, The rotation speed after shifting in the main transmission (102) can be changed by the output transmission (132), and the output of the main transmission (102) can be changed by the auxiliary transmission (113). [Brief explanation of the drawing]

[0013] [Figure 1] This is an explanatory diagram of a tractor as an example of the work vehicle according to the embodiment. [Figure 2] This is an explanatory diagram of the power transmission system according to the embodiment. [Figure 3] This is an explanatory diagram of the display unit according to the embodiment. [Figure 4] This is a functional block diagram of the control unit according to the embodiment.

Mode for Carrying Out the Invention

[0014] The embodiments of this invention will be described below. FIG. 1 is an explanatory diagram of a tractor as an example of the work vehicle according to the embodiment. In FIG. 1, a snow-removing tractor 1 as an example of the work vehicle of the present invention includes front wheels 2, 2 and rear wheels 3, 3 at the front and rear of a traveling vehicle body 1a, and the rotational power of an engine E mounted in an engine room 4 at the front of the traveling vehicle body is appropriately decelerated by a transmission in a transmission case 5 and transmitted to these front wheels 2, 2 and rear wheels 3, 3. The engine room 4 is configured to be covered by a bonnet 6. Also, at the rear of the tractor 1, a work implement such as a chemical spraying machine 18 for spraying chemicals (such as snow-melting agents and anti-freezing agents) onto the road surface behind the tractor 1 is mounted, and is configured to drive the work implement with a rear PTO shaft described later. Also, a snow-removing brush 26 as an example of a work implement is mounted at the front of the vehicle body. The snow-removing brush 26 is composed of a rotating brush that blows the snow on the road surface to the side. The snow-removing brush 26 is driven by a mid PTO shaft described later. In this specification, the left and right sides are referred to as the left side and the right side respectively toward the forward direction of the tractor 1, the forward direction is referred to as the front side, and the reverse direction is referred to as the rear side.

[0015] On the upper part of the traveling vehicle body 1a, a cab 7 is supported. Inside the cab 7, a driver's seat 8 is arranged at the upper position of the transmission case 5. In front of this driver's seat 8, a steering wheel 10, a forward and reverse lever 11, a parking brake (not shown), etc. are arranged. Also, in front of the driver's seat 8, a display panel such as a speedometer (not shown) and various operation switches (not shown) are arranged. At the lower front part of the driver's seat 8, traveling operation tools such as a brake 12 and an accelerator pedal 13 are arranged.

[0016] In FIG. 1, a hydraulic cylinder case 14 is provided above the rear part of the transmission case 5. On both the left and right sides of this hydraulic cylinder case 14, lift arms 15, 15 are pivotally attached so as to be rotatable. Between the lift arms 15, 15 and the lower links 16, 16, lift rods 17, 17 are interposed and connected. To the rear part of the lower links 16, 16, a chemical sprayer 18 as an example of a working machine is connected.

[0017] When hydraulic oil is supplied to a hydraulic cylinder 14a housed in the hydraulic cylinder case 14, the lift arms 15, 15 are rotated to the ascending side, and the working machine (chemical sprayer) 18 rises via the lift rods 17, the lower links 16, etc. Conversely, when the hydraulic oil in the hydraulic cylinder 14a is discharged into the transmission case 5 which also serves as a hydraulic tank, the lift arms 15, 15 descend. At the base end of the lift arm 15, a position sensor SN1 for detecting the tilt angle of the lift arm 15, that is, the raising and lowering of the working machine 18, is arranged.

[0018] In addition, as working machines attached to the rear part of the traveling vehicle body 1a, that is, working machines driven by power transmitted from the rear PTO shaft, in addition to the chemical sprayer, there are agricultural working machines such as a rotary tilling device for agricultural work, a plow, a seeder, a seedling transplanter, a fertilizer spreader, a chemical sprayer, etc. In addition, besides the snow removal brush 26, other implements that can be attached to the front of the vehicle body 1a, that is, implements that receive power from the mid-PTO shaft, include, for example, a lawnmower or a loader capable of transporting samples, pasture grass, soil, crops, etc., in a bucket.

[0019] (Explanation of the power transmission system) Figure 2 is an explanatory diagram of the power transmission system according to the embodiment. In Figure 2, in the work vehicle 1 of the embodiment, the output shaft 101 from the engine E is input to the pump section 102a of a continuously variable transmission (HST: Hydraulic Static Transmission) 102, which is an example of a main transmission and an example of a forward / reverse switching device. The power from the output shaft 101 input to the pump section 102a is output directly from the pump output shaft 103. Furthermore, the power input to the pump section 102a is shifted via the motor section 102b and output from the motor output shaft 104.

[0020] The output from the motor output shaft 104 is input to the sub-transmission 113 via the first transmission gear 111 and the second transmission gear 112. The sub-transmission 113 in this embodiment is configured to be able to change speed in three stages by combining three sets of gears 113a to 113f with different gear ratios, thereby changing the rotational speed of the sub-transmission output shaft 114. The drive of the sub-transmission output shaft 114 is transmitted to the rear wheel drive shaft 119 via the rear differential (actuator) 115, the third transmission gear 117, and the fourth transmission gear 118. As a result, the rear wheels 3 are driven.

[0021] Furthermore, the drive of the auxiliary transmission output shaft 114 is transmitted to the front wheel transmission shaft 124 via the front fifth transmission gear 121, sixth transmission gear 122, and seventh transmission gear 123. The rotation of the front wheel transmission shaft 124 is configured to be transmitted to the front wheels 2. A 2WD / 4WD switching clutch 126 is positioned between the seventh transmission gear 123 and the front wheel transmission shaft 124. When the 2WD / 4WD switching clutch 126 is "off", power is not transmitted to the two front wheels, resulting in two-wheel drive operation. When the 2WD / 4WD switching clutch 126 is "on", power is transmitted to the two front wheels, resulting in four-wheel drive operation.

[0022] A hydraulic clutch 131, an example of an output on / off device, is mounted at the rear of the pump output shaft 103. The hydraulic clutch 131 is configured to switch between transmitting and disconnecting power to the PTO side depending on whether it is switched "on" or "off". Rear of the hydraulic clutch 131 is a PTO transmission 132, which is an example of an output transmission. The PTO transmission 132 is configured to shift in two stages by combining two sets of gears 132a to 132d with different gear ratios. In other words, the PTO transmission 132 can switch the power from the engine E between low speed (low rotation) and high speed (high rotation). In this embodiment, a configuration that allows for two-stage shifting of the PTO transmission 132 is illustrated, but it is also possible to configure it to shift in three or more stages. Whether the PTO transmission 132 is set to the high rotation side or the low rotation side is detected by a detection member (sensor) (not shown) and input to the control unit 210.

[0023] The power output to the PTO transmission output shaft 133 of the PTO transmission 132 is transmitted to the PTO spindle 136 via the eighth transmission gear 134 and the ninth transmission gear 135. The power transmitted to the PTO spindle 136 can be transmitted to the rear PTO shaft 141, which is an example of a first output shaft, via the rear PTO clutch 137, which is an example of an output on / off device, and the tenth transmission gear 138 and the eleventh transmission gear 139. In this embodiment, when the rear PTO clutch 137 is "off", no power is transmitted to the rear PTO shaft 141, and when the rear PTO clutch 137 is "on", power is transmitted to the rear PTO shaft 141.

[0024] A 12th transmission gear 142 is positioned in front of the rear PTO clutch 137 (towards the engine E), and the rotation of the 12th transmission gear 142 can be transmitted to the mid-PTO shaft 146, which is an example of a second output shaft, via the 13th transmission gear 143 and the mid-PTO clutch 144, which is an example of an output on / off device. In this embodiment, when the mid-PTO clutch 144 is in the "off" state, no power is transmitted to the mid-PTO shaft 146, and when the mid-PTO clutch 144 is in the "on" state, power is transmitted to the mid-PTO shaft 146. In this embodiment, the position of the 12th transmission gear 142 corresponds to the branching point where the transmission path for driving to the rear PTO shaft 141 branches off from the transmission path for driving to the mid PTO shaft 146.

[0025] (Explanation of the display) Figure 3 is an explanatory diagram of the display unit of the embodiment. In Figure 3, the display panel 151 of the embodiment has a tachometer (speed display unit) 152 that displays the rotational speed of the engine E. The tachometer 152 is provided with a first speed lamp 152a as an example of a first display unit, at a position that serves as a guideline for the engine speed during operation when the PTO transmission 132 is set to the high-speed side.

[0026] Furthermore, the tachometer 152 is equipped with a second rotation speed lamp 152b, which serves as an example of a second display unit, at a position that indicates the engine speed during operation when the PTO transmission 132 is set to the low rotation side. In Figure 3, the first rotation speed lamp 152a on the high rotation side is positioned at a lower rotation speed than the second rotation speed lamp 152b on the low rotation side, so that the rotation speed output to the rear PTO shaft 141 and the mid PTO shaft 146 is approximately the same whether the PTO transmission 132 is set to the high rotation side or the low rotation side. When the PTO transmission 132 is set to the high rotation side, the first rotation speed lamp 152a is illuminated, and when the PTO transmission 132 is set to the low rotation side, the second rotation speed lamp 152b is illuminated. Furthermore, it is preferable to use highly visible LED lamps for lamps 152a and 152b. In addition, it is preferable to use a pictogram (a designation) rather than an alphabet or Chinese character for the symbol mark displayed at the location of lamps 152a and 152b, so that it can be easily recognized in regions with different languages.

[0027] The display panel 151 is also equipped with multiple display units, including a directional support unit 156, a fuel level indicator unit 157, a battery replacement indicator unit 158, a light indicator unit 159, and a parking brake indicator unit 160. The display panel 151 is also equipped with a PTO high-speed setting lamp 161 to indicate that the PTO transmission 132 is set to high-speed, and a PTO low-speed setting lamp 162 to indicate that the PTO transmission 132 is set to low-speed. Furthermore, the display panel 151 is equipped with a clutch operation lamp (an example of a clutch operation indicator unit) 163 that lights up when the hydraulic clutch 131 is disengaged, prompting the user to operate the PTO clutch switch SW1, which is used to input the engagement and disengagement of the hydraulic clutch.

[0028] (Description of the control unit) Figure 4 is a functional block diagram of the control unit according to the embodiment. In the block diagram of Figure 4, elements unrelated to the description of the embodiments of the present invention are omitted from the illustration and description.

[0029] (Explanation of the tractor's control unit) The tractor 1 of this embodiment has a control unit 210 that controls each function. The control unit 210 has an input / output interface (I / O) for inputting and outputting signals to and from the outside. The control unit 210 also has a ROM (read-only memory) in which programs and information for performing necessary processing are stored. The control unit 210 also has a RAM (random access memory) for temporarily storing necessary data. The control unit 210 also has a CPU (central processing unit) that performs processing according to the programs stored in the ROM, etc. Therefore, the control unit 210 of this embodiment is composed of a small information processing device, a so-called microcomputer. Thus, the control unit 210 can realize various functions by executing programs stored in the ROM, etc.

[0030] The control unit 210 receives signals from signal input elements such as the main shift lever 201, the sub-shift lever 202, the 2WD / 4WD selector lever 203, the PTO clutch switch SW1, the PTO shift lever 204, the rear PTO clutch switch SW2, the mid PTO clutch switch SW3, and various other sensors (not shown). The main shift lever 201 controls the rotational speed of the motor output shaft 104 via the HST 102. The auxiliary transmission lever 202 controls the rotational speed of the auxiliary transmission output shaft 114 via the auxiliary transmission device 113. The 2WD / 4WD selector lever 203 switches between two-wheel drive and four-wheel drive via the 2WD / 4WD selector clutch 126.

[0031] The PTO clutch switch SW1 controls the transmission / disconnection of power to the PTO spindle 136 via the hydraulic clutch 131. The PTO speed control lever 204 controls the rotational speed of the power supplied to the PTO spindle 136 via the PTO transmission 132. The rear PTO clutch switch SW2 switches the power transmission to the rear PTO shaft 141 on and off via the rear PTO clutch 137. The mid-PTO clutch switch SW3 switches the power transmission to the mid-PTO shaft 146 on and off via the mid-PTO clutch 144.

[0032] Furthermore, the control unit 210 can control the tractor 1's movement, stopping, acceleration / deceleration, driving and lifting of implements, etc., by transmitting control signals to elements such as the engine E, HST 102, and hydraulic clutch 131, which are examples of controlled elements.

[0033] In Figure 4, the control unit 210 of this embodiment has the following functional means (program module). The PTO clutch control means 211 of the control unit 210 controls the hydraulic clutch 131 to a disengaged state when the PTO transmission 132 is rotating at a high speed and the engine E's rotational speed reaches a predetermined speed (for example, 2150 rpm), thereby cutting off the transmission of rotation to the rear PTO shaft 141 and the mid PTO shaft 146. When the PTO transmission 132 is rotating at a high speed and the engine E's rotational speed is high, the rotational speed of the rear PTO shaft 141 and the mid PTO shaft 146 can become too high, potentially damaging the work equipment. Disengaging the hydraulic clutch 131 ensures safety. Furthermore, when the PTO clutch control means 211 disengages the hydraulic clutch 131, the control unit 210 controls the system to illuminate the clutch operation lamp 163 when the engine E's rotational speed falls below 2150 rpm.

[0034] In this embodiment, the PTO clutch control means 211 disengages the hydraulic clutch 131 if the engine E's rotational speed does not reach a predetermined low rotational speed (for example, 500 rpm). A very low engine speed may indicate a malfunction of the sensor that detects the engine E's rotational speed or a broken wire. If the detection of the engine E's rotational speed is inaccurate due to a sensor malfunction or the like, and the operator accidentally revs the engine E, the detected rotational speed will remain low, while the actual engine E's rotational speed will be higher. If the hydraulic clutch 131 remains engaged at this time, the implements 18 and 26 will rotate at high speed, which could lead to damage to the implements 18 and 26 or cause an accident. Therefore, in this embodiment, the hydraulic clutch 131 is disengaged when the engine E's rotational speed does not reach a low rotational speed, thereby suppressing damage to the implements 18 and 26 and preventing accidents.

[0035] In the tractor 1 of this embodiment, which has the above configuration, a PTO transmission 132 is positioned between the HST 102 and the rear PTO shaft 141 and the mid PTO shaft 146. Therefore, by operating the PTO transmission 132, it is possible to adjust the rotational speed of the rear PTO shaft 141 and the mid PTO shaft 146 without changing the rotational speed of the engine E, or to adjust it to the rotational speed required by the implement. Thus, the problem of insufficient torque due to low rotational speed of the engine E, as in conventional configurations, is suppressed, and adverse effects on work are suppressed. In particular, in this embodiment, the PTO transmission 132 is located at the rear of the HST 102, in front of the sub-transmission 113, etc., that is, inside the vehicle body 1a. Therefore, compared to the case where it is located at the rear of the vehicle body 1a, where space constraints are numerous, it is possible to effectively utilize the relatively spacious interior of the vehicle body 1a to change the rotation speed of the PTO shafts 141 and 146.

[0036] Furthermore, in this embodiment, when the PTO transmission 132 is at a high rotational speed and the engine E is at a high rotational speed, the hydraulic clutch 131 is disengaged. Therefore, damage to the implement due to excessively high rotational speeds of the rear PTO shaft 141 or the mid-PTO shaft 146 is suppressed. Furthermore, if the hydraulic clutch 131 is disengaged, the engine speed E will decrease, causing the clutch operation lamp 163 to illuminate, informing the operator that power is not being transmitted to the implement and that input to the PTO clutch switch SW1 is required. This prevents the operator from driving with the implement not operating without realizing it has stopped, and also allows them to confirm and recognize that input to the PTO clutch switch SW1 is required.

[0037] Furthermore, in this embodiment, when the PTO transmission 132 is set to a high rotation speed, the first rotation speed lamp 152a is illuminated, and when the PTO transmission 132 is set to a low rotation speed, the second rotation speed lamp 152b is illuminated. Therefore, the operator can easily check and recognize what the engine speed E should be during operation, improving work efficiency.

[0038] (Example of change) The work vehicle of the present invention is not limited to tractors, but can also be applied to various work vehicles equipped with work implements such as seedling transplanters and chemical spraying vehicles. Furthermore, the work implements are not limited to chemical sprayers 18 and snow removal brushes 26, but can be any work implement such as seedling transplanters, land levelers, seeders, and fertilizer applicators. Furthermore, while the example given illustrates a configuration in which a worker is on board and operates the work vehicle, the system is not limited to this. It can also be applied to autonomous work vehicles. The above embodiment is not limited to cases where implements are mounted on both the rear PTO shaft 141 and the mid-PTO shaft 146 simultaneously. Depending on the application of the work vehicle, the present invention is also applicable when implements are mounted on only one of the PTO shafts 141 or 146 and the other is not. [Explanation of Symbols]

[0039] 1…Work vehicles, 1a... Vehicle body, 131... Clutch, 132... Output transmission, 141...First output shaft, 142... Branching point, 146...Second output shaft, 152... Rotation speed display section, 152a...First display unit, 152b...Second display unit, 163...Clutch operation display unit, 210... Control unit, E... Engine.

Claims

1. A vehicle body (1a) having an engine (E), A rear PTO shaft (141) capable of outputting power from the engine (E), A mid-PTO shaft (146) branches off from the transmission path of the rear PTO shaft (141) and is capable of outputting power from the engine (E) to a position different from that of the rear PTO shaft (141), An output transmission (132) capable of changing the rotational speed of the rear PTO shaft (141) and the mid PTO shaft (146), A main transmission (102) that changes the speed of the power transmitted from the engine (E) to the rear wheels (3), A hydraulic clutch (131) switches the transmission of power to the rear PTO shaft (141) and the mid PTO shaft (146) on and off, A rear PTO clutch (137) switches the transmission of power to the rear PTO shaft (141) on and off, A mid-PTO clutch (144) switches the transmission of power to the mid-PTO shaft (146) on and off, Equipped with, The output transmission (132) is positioned on the engine (E) side of the branching point (142) between the rear PTO shaft (141) and the mid PTO shaft (146), and behind the main transmission (102). The rear PTO clutch (137) is provided adjacent to the branching position (142) and on the rear PTO shaft (141) side of the branching position (142). The mid-PTO clutch (144) is mounted on the mid-PTO shaft (146). A work vehicle (1) characterized by the following:

2. A control unit (210) that disengages the hydraulic clutch (131) when the output transmission (132) shifts the power of the engine (E) to a predetermined high rotational speed and the rotational speed of the engine (E) reaches a predetermined rotational speed, A work vehicle (1) according to claim 1, characterized by being equipped with the following:

3. An engine speed display unit (152) that displays the rotational speed of the engine (E), comprising: a first display unit (152a) positioned at a location that serves as an estimate of the engine speed when the output transmission (132) is set to the high rotational speed side during operation; and a second display unit (152b) positioned at a location that serves as an estimate of the engine speed when the output transmission (132) is set to the low rotational speed side during operation; A work vehicle (1) according to claim 1 or 2, characterized by being equipped with the following:

4. The system includes a sub-transmission (113) that changes the speed of the power output from the main transmission (102), The output transmission (132) is positioned between the main transmission (102) and the auxiliary transmission (113) in the front-rear direction. The work vehicle (1) according to feature 1.

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