JP7290142B2 - work vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a work vehicle such as a chemical sprayer that has a boom for spraying a chemical solution in front of its body and that sprays the chemical solution.

The work vehicle shown in Prior Patent Documents 1 and 2 includes a front transmission case that obtains driving force from the engine, a dry clutch that turns on and off transmission from the front transmission case to the downstream side of the transmission, a driving system and a boom sprayer that transmit the driving force. The front transmission case is provided with a PTO shaft (regular PTO, live PTO) for transmitting driving force to a pest control pump or the like.

By providing the PTO shaft in the front transmission case, the transmission to the rear transmission case is interrupted by disengaging the dry clutch, and rotation can be continued even when the vehicle is stopped from traveling or working.

As a result, it is possible to prevent the occurrence of a time lag until the pest control pump or the like is started when resuming traveling and work, and the occurrence of places where the chemical is not sprayed when resuming work traveling (for example, Patent Document 1, Patent Document 2). reference).

JP-A-2020-001612 JP-A-2002-346444

However, because the transmission case has a split structure in order to keep the PTO shaft rotating at all times, the number of parts increases. Therefore, there is a problem that the time and labor required for maintenance become large.

In addition, although power loss is suppressed by using a dry clutch, there is a problem that wear is likely to occur and replacement frequency increases.

An object of the present invention is to provide a work vehicle that is easy to maintain in consideration of such problems of conventional work vehicles.

A first aspect of the present invention is
a running vehicle;
a working device for performing management work in the field;
A work vehicle comprising a transmission case for transmitting traveling driving force and working driving force,
The mission case is
a front case for mounting hydraulic components;
a rear case for mounting the HST;
a central case for mounting the traveling transmission member and the work transmission member;
The work vehicle is characterized in that the central case is fixed to a traveling vehicle body.

A second aspect of the present invention is
The traveling vehicle body can be equipped with an additional working device for performing work different from the working device,
The central case is provided with a clutch for switching traveling transmission and work transmission,
A relay transmission member is provided on the upper transmission side of the clutch,
A relay transmission case for transmitting the driving force of the relay transmission member,
An extension transmission shaft that transmits power to the extension work device is arranged in the relay transmission case,
The work vehicle according to the first aspect of the present invention, wherein the relay transmission case is detachable.

A third aspect of the present invention is
The relay transmission case is arranged on the front side of the front case of the mission case, and
The work vehicle according to the second aspect of the present invention, wherein the additional transmission shaft is arranged near or above the upper surface of the central case.

The fourth aspect of the present invention is
The clutch includes a plurality of clutch plates embedded in a clutch case, and the clutch case is provided on the clutch drive shaft,
The clutch drive shaft has a flow path for hydraulic oil and supplies the hydraulic oil to the inner peripheral side of the clutch plate, and the clutch case has a return hole for returning the hydraulic oil entering the clutch case to the hydraulic circuit A work vehicle according to the second or third aspect of the present invention, comprising:

The fifth aspect of the present invention is
The work vehicle according to the fourth aspect of the present invention, wherein the clutch plate has communication holes extending from the inner circumference to the outer circumference.

According to the first aspect of the present invention, the transmission case is divided into front, center, and rear parts, and the central case is fixed to the traveling vehicle body, so that maintenance work can be performed inside the case without removing the entire transmission case from the airframe. becomes.

According to the second aspect of the present invention, by supplying the driving force to the additional work device from the relay drive member provided on the upper side of the transmission than the clutch, the transmission to the additional work device is not stopped even if traveling and work are interrupted. Therefore, it is possible to prevent the operation of the additional work device from being delayed at the time of resuming the traveling and work, and the occurrence of work unevenness.

In addition, by making the relay transmission case detachable, when the additional work device is not used, transmission is not performed after the relay drive member, so power loss can be suppressed, and stability of operation and improvement of fuel efficiency can be achieved.

According to the third aspect of the present invention, by arranging the relay transmission case on the front side of the front side case of the mission case, it is not necessary to attach or detach other parts, or the number of parts to be attached and detached can be reduced. can. In addition, by arranging the additional transmission shaft near the upper surface of the transmission case or above the upper surface, the additional transmission shaft can be arranged without forming an avoidance portion in the transmission case.

According to the fourth aspect of the present invention, by supplying hydraulic oil from the passage of the clutch drive shaft into the clutch case, it is possible to prevent the clutch plates from seizing and becoming immobile. can be cut. In addition, since the return hole is formed in the clutch case, the working oil that has entered the clutch case can be returned to the hydraulic circuit, thereby preventing an increase in internal pressure and a shortage of working oil.

According to the fifth aspect of the present invention, since the communication hole is formed, the hydraulic oil that has entered between the clutch plate and the clutch case can be moved out of the clutch case. It prevents problems from occurring due to aging.

1 is a side view of a work vehicle according to an embodiment of the present invention; FIG. Perspective view of the transmission case of the work vehicle seen from the front Perspective view of the transmission case of the work vehicle seen from the rear Perspective view of the transmission case of the same work vehicle as seen from the rear lower side Schematic sectional view of the transmission case Enlarged view of the clutch in the transmission case Perspective view of the front case of the transmission case seen from the front Perspective view of the front case of the transmission case seen from the inside Perspective view of the central case of the transmission case seen from the front Perspective view of the central case of the transmission case seen from the rear Perspective view of the rear case of the transmission case seen from the inside Perspective view of the rear case of the transmission case seen from the rear FIG. 2 is a schematic perspective view of a transmission case according to a second embodiment of the present invention; 1 is a front view of a clutch plate according to an embodiment of the present invention; FIG. (A), (B), (C) diagrams for explaining the pest control machine operation BOX according to the embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment of the present invention, a working vehicle for pest control that sprays agricultural chemicals will be described as an example.

FIG. 1 is a schematic left side view of the work vehicle 1. FIG. In this specification, the side of the work vehicle 1 in the direction of travel is the front, the opposite side is the rear, the left side in the direction of travel is the left, and the right side in the direction of travel is the right.

As shown in FIG. 1, a work vehicle 1 is a vehicle for spraying a chemical solution for pest control. It has front wheels 2 and rear wheels 3, and an engine ( not shown) are covered. An operator's seat section 5 is provided behind the bonnet 4 , and the operator's seat section 5 is provided with a steering handle 6 and a seat 8 .

A chemical solution tank 9 containing a chemical solution is detachably mounted behind the seat 8 . The work vehicle 1 also includes a hydraulic continuously variable transmission (HST), which is a mechanism capable of adjusting forward/reverse movement and speed of the vehicle, and an engine start restricting device that restricts engine start.

Support brackets 12a projecting in the left-right direction are provided on both left and right sides of the front portion of the vehicle body of the work vehicle 1, and the left and right support brackets 12a are provided with elevating links 12 each constituted by an upper and lower link body. It is rotatably supported. The upper and lower link bodies of the lifting link 12 are configured to be interlocked with each other. At the lower stage of the link body of the lifting link 12, a telescopic lifting cylinder 13 is connected between the lower stage of the link body of the lifting link 12 and the support bracket 12a. , the lifting link 12 can be vertically swung by expanding and contracting the lifting cylinder 13 .

Also, the lifting link 12 extends to a position in front of the bonnet 4 , and a front frame 11 is attached to the front end of the lifting link 12 so as to connect the left and right lifting links 12 . Therefore, by simultaneously extending and contracting the left and right lifting cylinders 13, the front frame 11 can be lifted and lowered via the left and right lifting links 12 that move up and down.

At both ends of the front frame 11, a pair of left and right pest control booms 10 for spraying a chemical solution are attached so as to be rotatable about vertical axes. A boom switching cylinder is provided to enable folding. A plurality of nozzles 10a are attached to the pest control boom 10, and a plurality of nozzles 11a are attached to the front frame 11, respectively. It is configured so that it can be sprayed and sprayed. In addition, in FIG. 1, the pest control boom 10 on the right side is omitted from the drawing.

A state in which the pest control boom 10 is folded and placed along the vehicle body is called a retracted posture, and a state in which the pest control boom 10 is unfolded and extended to the left and right is called a chemical spraying posture. In the storage posture, by placing the pest control boom 10 on boom receivers 15 provided on both the left and right sides of the working vehicle 1, the pest control boom 10 can be held in a state of being directed obliquely upward rearward of the vehicle body.

2 is a perspective view of the transmission case 20 mounted on the work vehicle of the present embodiment as seen from the front to the rear, FIG. 3 is a perspective view of the transmission case 20 as seen from the rear to the front, and FIG. 2 is a perspective view of the transmission case 20 of FIG. 2 as seen from the bottom side.

2, 3 and 4, reference numeral 21 denotes a front case, 22 a central case, 22a a bottom surface of the central case 22, and 23 a rear case. Further, 24 is an input shaft for power transmission from the engine, and 25 and 26 are first and second hydraulic pumps. Reference numeral 27 denotes a shaft for turning on and off a clutch, which will be described later; 28, a lift valve in the rear; 30 is a hydraulic continuously variable transmission (HST), and 31 is a clutch lubrication hole. Also, 32 is a PTO shaft for a working device such as a boom sprayer, 33 is a live PTO output shaft (additional transmission shaft) described later, 34 is a vehicle speed sensor, 35 is a drain, 36 is an auxiliary transmission shaft, 37 is a breather, 38 is a travel output shaft that transmits driving force for driving the rear wheels 3 .

Furthermore, the inside of the mission case 20 has a structure as shown in FIGS. 5 is a schematic cross-sectional view of the whole, and FIG. 6 is an enlarged view centering on the clutch 55. As shown in FIG.

First, the front case 21 will be mainly described. 7 is a perspective view of the front case 21 as seen from the front side, and FIG. 8 is a perspective view of the front case 21 as seen from the rear side. 7 and 8, ball bearings are omitted. The input shaft 24 is held by the input bearing 21a. A gear 40 is connected to the rear end of the input shaft 24 . A gear 41 fixed to a clutch drive shaft 42 meshes with the gear 40 . A front end of the clutch drive shaft 42 is supported by a clutch front bearing 43 formed in the front case 21 . 55 is a clutch here.

Further, the gear 41 is meshed with a gear 44 located below it, and this gear 44 is fixed to a gear pump drive shaft 45 that drives the first hydraulic pump 25. A gear pump bearing 45 is a bearing of the gear pump drive shaft 45. are formed in the front case 21 .

On the other hand, a gear 47 attached to a shaft 48 is engaged above the gear 40 , and the tip of the shaft 48 is supported by a bearing 49 formed in the front case 21 . Further, the rear end of the shaft 48 is supported by a bearing 50a provided in a portion of a bearing plate portion 50 attached to the central case 22 side. A gear 51 is attached near the center of the shaft 48, and a gear 52 is meshed with the gear 51, and the gear 52 is fixed to the live PTO output shaft 33 described above. The front end of the live PTO shaft 33 is supported by a bearing 54 formed in the front case 21, and the rear end thereof is supported by a bearing 50b formed in the bearing plate portion 50 and protrudes rearward to form a live PTO. It can be used as an output shaft.

Here, when the driving force of the engine is input from the input shaft 24, the gear 40 rotates. The gear 47 meshing with the rotation rotates, and the shaft 48 rotates. The rotation of the shaft 48 causes the gear 51 to rotate and the meshing gear 52 to rotate.

As a result, the live PTO output shaft 33 fixed to the gear 52 rotates, and the driving force from the engine is extracted to the outside. Since this driving force is extracted from the upstream side (upper side) of the clutch 55, the driving force can be extracted while the engine is running without being influenced by whether the clutch 55 is turned on or off.

Further, the gear 40 is meshed with a gear 41, which is fixed to the clutch drive shaft 42, so that the driving force of the engine is transmitted from the input shaft 24 to the clutch drive shaft 42 as well. Clutch drive shaft 42 is connected to clutch 55 . Therefore, the driving force transmitted to the clutch drive shaft 42 is affected by the on/off state of the clutch 55 .

Further, the gear 41 is meshed with a gear 44, and the driving force of the engine is also transmitted from the input shaft 24 to the gear pump driving shaft 45 to which the gear 44 is fixed. The rotation of the gear pump drive shaft 45 drives the first hydraulic pump 25 . A second hydraulic pump 26 attached to the front case 21 is also driven by the same mechanism.

Next, the central case 22 and the rear case 23 will be described. As shown in FIGS. 9 and 10, the central case 22 is detachable from the periphery with a front case 21 and a rear case 23 and a bolt mechanism. As shown in FIG. 5, A indicates the interface between the front case 21 and the central case 22, and B indicates the interface between the central case 22 and the rear case 23. As shown in FIG. Also, the center case 22 is fixed to the frame of the traveling vehicle body 1' of the work vehicle 1 by a connecting portion 53 (see FIG. 10). 11 is a perspective view of the rear case 23 as seen from the inside, and FIG. 12 is a perspective view of the rear case 23 as seen from the outside.

Inside the central case 22, the bearing plate portion 50 and the clutch bearing plate portion 57 are formed at the front position and the center position, respectively.

A clutch 55 is arranged between the front bearing plate portion 50 and the clutch bearing plate portion 57 , and the clutch drive shaft 42 is pivotally supported by the bearing portion 60 of the clutch bearing plate portion 57 via the clutch 55 . Further, the rear portion of the clutch drive shaft 42 passes through a hole 61 (see FIG. 10) of the bearing portion 60 and is supported by a clutch drive shaft bearing 62 of the rear case 23 .

Since the HST drive shaft is supported by the rear case 23, it is cantilevered by the rear case 23 or fixed to the HST itself.

Further, since the drive shaft is longitudinally long, it is supported by the front case 21 , center case 22 and rear case 23 .

Further, a speed change gear 70 is fixed to the clutch drive shaft 42, and the speed change gear 70 is meshed with a gear 71 attached to the shaft of the working device PTO shaft 32, so that the rotation of the clutch drive shaft 42 is controlled by the PTO shaft 32. It is transmitted to shaft 32 . Therefore, the rotation of the working device PTO shaft 32 is affected by the on/off state of the clutch 55 . A PTO bearing 32a is provided in the rear case 23. As shown in FIG.

On the other hand, a gear 63 is further attached to the clutch drive shaft 42, and the gear 63 meshes with the HST input gear 64. As shown in FIG. Further, the HST output gear 65 is connected to the traveling output shaft 29 of the front wheels and the traveling output shaft 38 of the rear wheels through three gear mechanisms 66, 67, 68. As shown in FIG. In FIG. 7, 29a is a bearing for the running output shaft 29 of the front wheels. Therefore, the output changed by the HST 30 is transmitted to the traveling output shafts 29 and 38. Here, 30a is the HST input side and 30b is the HST output side. 72 and 73 are an HST input bearing and an HST output bearing, respectively.

In this way, the transmission case 20 is divided into the front, center, and rear parts, and the center case 22 is fixed to the frame of the traveling vehicle body 1' of the work vehicle 1 (connecting portion 53), so that the entire mission case 20 can be used as a fuselage. Maintenance work inside the case can be performed without removing it from the case.

FIG. 13 shows a second embodiment of the invention. Here, from the input shaft 24 to the gear 40 and the gear 47 (counter gear, an example of the relay transmission member of the present invention) that meshes with it are the same as in the above example. In FIG. 13, 90 denotes a traveling system mechanism, and 91 denotes a PTO shaft system mechanism.

The rotational force of the gear 47 is transmitted through the shaft 80 to a pulley 81 fixed to its tip. Rotation of the pulley 81 is transmitted to another pulley 84 above via the belt 82 . Since the shaft 85 is fixed to this pulley 84, it rotates. This shaft 85 corresponds to the live PTO output shaft (additional transmission shaft) 33 described above. This shaft 85 is also not affected by the on/off of the clutch 55 and is always driven by the output from the engine.

Furthermore, these two pulleys 81 and 84 and the belt 82 are attached to a chain case 83 , and the chain case 83 is detachable from the front case 21 of the transmission case 20 .

By making the relay transmission case (chain case 83) detachable, power transmission is not performed after the gear 47 (relay transmission member) when the additional work device is not used, thereby suppressing power loss and stabilizing the operation. and improved fuel efficiency.

In other words, since there is a time lag from when the fertilizer spreader starts to when the supply operation is stabilized, if the transmission is stopped when the clutch is turned on and off, the work will not be performed when the clutch is turned on. Or, work is done incompletely, resulting in work irregularities. In addition, even when the live PTO output shaft is not equipped with a fertilizer spreader or the like, the driving force is not transmitted, so power loss does not occur.

In this embodiment, the chain case 83 is positioned forward of the front case 21 of the transmission case 20, and the shaft 85, which is the live PTO output shaft (additional transmission shaft) 33, is positioned near the upper surface of the central case 22, Or it is arranged above it.

As a result, there is no need to attach/detach other parts when attaching/detaching, or the number of parts to be attached/detached can be reduced. In addition, by arranging the shaft 85, which is the additional transmission shaft, near the upper surface of the transmission case 20 or above the upper surface, the additional transmission shaft 33 can be moved backward without forming an avoidance portion in the transmission case 20 itself. It has the advantage of being placed

Next, the clutch 55 in this embodiment has a wet structure rather than a so-called dry structure. That is, as shown in FIGS. 5 and 6, both ends of the clutch drive shaft 42 are supported by the front case 21 and the rear case 23 (43, 62), and an oil passage is formed between the shaft and the support. formed. Lubricating oil is supplied from clutch lubricating holes 31 . The lubricating oil carries the hydraulic pressure return of the pesticide back to the clutch drive shaft 42 oil passage.

The clutch 55 is constructed by housing a plurality of clutch plates 55b in a clutch case 55a and providing the clutch case 55a on the clutch drive shaft . Further, the clutch drive shaft 42 has a flow path for hydraulic oil, and can supply the hydraulic oil to the inner peripheral side of the clutch plate 55b. Further, the clutch case 55a is formed with a return hole for returning the working oil that has entered the clutch case 55a to the hydraulic circuit. 14 shows the clutch plate 55b, which has a communication hole 92 extending from the inner circumference to the outer circumference as indicated by an arrow C. As shown in FIG.

Since the clutch 55 has such a structure, it is possible to prevent the clutch plate 55b from seizing and becoming immobile by supplying hydraulic oil from the passage of the clutch drive shaft into the clutch case 55a. can be reliably turned on and off.

In addition, since the return hole is formed in the clutch case 55a, the working oil that has entered the clutch case 55a can be returned to the hydraulic circuit, thereby preventing an increase in internal pressure and a shortage of working oil.

In addition, since the communication hole 92 is formed, the hydraulic oil that has entered between the clutch plate 55b and the clutch case 55a can be moved out of the clutch case 55a, so that the hydraulic oil that does not return to the flow path becomes old. to prevent problems from occurring.

FIGS. 15A, 15B, and 15C are drawings for explaining the pest control machine operation BOX. In this example, the pest control machine operation box 100 is provided not on the liquid chemical tank 9 side but on the operation section 5 side. If it is provided on the chemical liquid tank 9 side, it is inconvenient because it cannot be operated when the chemical liquid tank 9 is removed. By providing it on the operation part 5 side, even when the chemical liquid tank 9 is removed, the side boom 10 or the like can be raised and lowered, which is convenient. For example, while the side boom 10 is attached, work such as cultivating can be performed.

The operation box 100 is arranged on the right side of the steering wheel 97 . The main shift lever 95 is on the left side, and the throttle lever of the engine is on the right side, but since the throttle lever is used infrequently, the operation box 100 is arranged behind the throttle lever. By doing so, it becomes possible to hold the steering wheel 97 with the right hand while holding the main shift lever 95 with the left hand and operate the operation box 100 with the right fingers. Since the steering wheel 97 is not largely moved during pest control work, there is no inconvenience. When turning, the steering wheel 97 is moved with the left hand.

The operation box 100 is provided at a position higher than the steering wheel 97 and the throttle lever. While gripping the upper right portion of the steering wheel 97, it is positioned so that it can be operated with fingers.

A lift switch 96 for the boom link is provided on the meter panel 101 side. This is because it is also used for lifting and lowering the working machine. In the case of the single work machine model, there is no problem even if the pest control machine operation box 100 is removed.

As shown in FIG. 15(C), it is desirable that the mounting angle S of the operation box 100 be the same as the angle S' of the steering wheel 97 . This is because the visibility is good and the operability is also good.

A stay 99 for mounting the operation box 100 is fastened together with the front wiper motor cover 98 . The stay 99 is positioned higher than the steering wheel 97, which has the advantage of not impairing the visibility of the lower right pedal and the right tire.

The switches on the operation box 100 are composed of a left-right cross switch and a left-right seesaw switch, as shown in FIG. 15(A) and L in the enlarged view (B). Keep it simple with fewer switches. The left and right cross switch raises and lowers the left and right side booms by operating it up and down, and expands and contracts the boom by operating it left and right. With the left cross switch, the outside expands and the inside contracts, and with the right cross switch, the outside shrinks and the inside expands. This is because intuitive operation becomes possible.

The opening and closing operation of the boom is done with the left switch to open the outside and close the inside. The right switch opens the outside and closes the inside. It can be operated intuitively.

The cross switch is arranged above and the on/off switch is arranged below. Normally, the open/close switch is flat and the cross switch has a long convex portion, so that they are configured so as not to interfere with each other's operations.

INDUSTRIAL APPLICABILITY The present invention can provide a work vehicle that is easy to maintain, and is useful as a work vehicle for pest control that sprays agricultural chemicals.

Reference Signs List 1 work vehicle 1' traveling vehicle body 2, 3 front wheels, rear wheels 20 mission case 21 front side case 22 center case 23 rear side case 24 input shaft 30 HST
33, 85 Live PTO output shaft (additional transmission shaft)
42 clutch drive shaft
47 gear (counter gear, relay transmission member)
53 connecting portion 55 clutch 55a clutch case 55b clutch plate 80 shaft 81, 84 pulley 83 chain case (relay transmission case)

Claims (5)

a running vehicle;
a working device for performing management work in the field;
A work vehicle comprising a transmission case for transmitting traveling driving force and working driving force,
The mission case is
a front case for mounting hydraulic components;
a rear case for mounting the HST;
a central case for mounting the traveling transmission member and the work transmission member;
A work vehicle, wherein the central case is fixed to the traveling vehicle body. The traveling vehicle body can be equipped with an additional working device for performing work different from the working device,
The central case is provided with a clutch for switching traveling transmission and work transmission,
A relay transmission member is provided on the upper transmission side of the clutch,
A relay transmission case for transmitting the driving force of the relay transmission member,
An extension transmission shaft that transmits power to the extension work device is arranged in the relay transmission case,
The work vehicle according to claim 1, wherein the relay transmission case is detachable. The relay transmission case is arranged on the front side of the front case of the mission case,
The work vehicle according to claim 2, wherein the additional transmission shaft is arranged near or above the upper surface of the central case. The clutch includes a plurality of clutch plates housed in a clutch case, and the clutch case is provided on a clutch drive shaft,
The clutch drive shaft has a flow path for hydraulic oil and supplies the hydraulic oil to the inner peripheral side of the clutch plate, and the clutch case has a return hole for returning the hydraulic oil entering the clutch case to the hydraulic circuit 4. The work vehicle according to claim 2 or 3, forming a 5. The work vehicle according to claim 4, wherein a communication hole is formed in said clutch plate from an inner circumference toward an outer circumference.

Images