KR20230083615A - Transmission for work vehicle - Google Patents

Abstract

The present invention relates to a transmission for a work vehicle. The transmission for the work vehicle including a forward/reverse clutch for forward/backward switching, comprises a forward/reverse hydraulic valve apparatus mounted on a left side wall of a housing of the transmission and capable of performing hydraulic control for the forward/backward switching and a wet main clutch function. The forward/reverse hydraulic valve apparatus is provided in a mechanically controlled method or an electronically controlled method. The forward/reverse hydraulic valve apparatus, provided as mechanically controlled or electronically controlled, may have a compatible interface to the housing. Provided is the transmission for the work vehicle, capable of enhancing product diversity.

Description

Transmission for work vehicle {TRANSMISSION FOR WORK VEHICLE}

The present invention relates to a transmission, and more particularly, to a transmission of a work vehicle that can apply both a mechanical operation method or an electronic control method while optimizing a valve device and sharing one interface in designing a wet clutch of the transmission. will be.

The work vehicle may refer to a vehicle capable of additionally performing work for the convenience of human life in addition to a vehicle for movement. A work vehicle can function as a transportation device that moves a worker to a specific location using a driving source such as an engine, and can move with a worker at a specific location or use power from a driving source other than driving while maintaining a stationary state. can be used for purpose.

As a general work vehicle, there may be an agricultural work vehicle such as a combine or a tractor, and in addition, there may be a work vehicle that performs other tasks at a construction site or a factory.

Referring to Japanese Patent Registration No. 3940195, a work vehicle including a PTO is disclosed. The work vehicle includes an engine, a transmission and a PTO device, and some of the power from the engine is transmitted to driving wheels and the like and used for driving, and the other portion is transmitted to the PTO device and the like and used for purposes other than driving.

The transmission includes a front housing, a mission housing, and a rear housing, and includes a driving power transmission unit for transmitting power from an engine to driving wheels and the like and a PTO power transmission unit for operations other than driving. As a driving power transmission unit, it includes a front and rear transmission unit, a main transmission unit, and a sub transmission unit. The front and rear transmission unit is located in the front housing, and the main transmission unit and the auxiliary transmission unit are located in the transmission housing. Power can be selectively transmitted.

Conventional PTO devices also include a PTO clutch, and there is one that controls the PTO clutch hydraulically. However, in many cases, the conventional hydraulic PTO clutch and its control device are installed far from each other, and because of the pressure loss, the hydraulic control curve controlled by the hydraulic control device is applied differently from the actual piston hydraulic pressure of the PTO clutch. .

In addition, since the positive/reverse part is operated by hydraulic pressure, a control valve device is provided at the bottom of the front housing, and the control valve device receives hydraulic oil from a hydraulic pump and can be used to control the hydraulic clutch of the normal/reverse part.

Conventionally, in designing a control valve device, a mechanical operation method and an electronic control method were separately distinguished, and separate designs were maintained for each.

The present invention configures the forward/reverse part and the peripheral transmission part as wet clutches, and provides a simple and optimized structure for a forward/reverse hydraulic valve device and a variable speed hydraulic valve device for controlling each clutch, so that mechanical and electronic types share one interface To provide a transmission of a work vehicle that can improve the diversity of products by doing so.

The present invention provides a transmission of a work vehicle that connects a forward/reverse hydraulic valve device and a variable speed hydraulic valve device with a hydraulic clutch, and can achieve both axis support and oil injection with one support member.

The present invention provides a transmission of a work vehicle capable of stably maintaining control pressure even when a forward/reverse hydraulic valve device and a variable speed hydraulic valve device are connected with one hydraulic pump and a variable speed hydraulic valve device is indirectly connected with a hydraulic pump.

The present invention arranges the forward and reverse hydraulic valve device on the left side of the transmission to facilitate the connection and wiring between the clutch pedal and the forward and reverse section, and arranges the shift hydraulic valve device on the right side of the transmission to respond to the operation of the main gear lever. A transmission of a work vehicle capable of facilitating wiring and the like is provided.

According to an exemplary embodiment of the present invention for achieving the above-described objects of the present invention, a transmission of a work vehicle including a forward and reverse clutch for forward and backward conversion is mounted on the left wall of a housing of the transmission to convert forward and reverse and Including a positive and negative hydraulic valve device capable of performing hydraulic control for a wet main clutch function, the positive and negative hydraulic valve device is provided in a mechanical control method or an electronic control method, and is provided in a mechanical control method or an electronic control method. The device may have a compatible interface to the housing.

The forward/reverse hydraulic valve device may be provided separately installed on the outer surface of the housing, more preferably on the left side, and may be provided as a modularized independent package and replaced with a mechanical control method maintaining the same interface or an electronic control method. .

The oil inlet, oil supply port and oil outlet formed in the forward and reverse valve block may be formed at the same location to be compatible with a mechanical control method or an electronic control method.

The oil outlet of the positive/reverse hydraulic valve device is located at a position higher than the oil level in the transmission and other internal parts of the positive/reverse hydraulic valve device to prevent air bubbles from being generated in the oil.

The normal/reverse hydraulic valve device may include a normal/reverse valve block mounted on one side wall of the housing, a normal/reverse control valve mounted on the normal/reverse valve block, and at least two first pipes connecting the normal/reverse hydraulic control valve and the support member. When the forward/reverse hydraulic valve device is located on the right side of the housing of the transmission, it may be located at an upper portion substantially corresponding to the height of the first shaft, and the operation of the forward/reverse clutch may be controlled through the first pipe.

In the valve device, the pipes are connected to the oil outlet of each device, and seals are formed at each end of the pipes to be inserted into the transmission so as to be sealed with the support member.

A plurality of through-holes corresponding to the respective pipes may be formed on a wall surface of the transmission to pass pipes connected to the forward/reverse valve block. The through-holes may be integrated into one and formed in a size that allows all pipes to pass therethrough, but the through-holes may be separately formed to support each pipe for stable support and guide of the pipes.

The housing may be provided by assembling a front housing, a mission housing, a differential housing, a rear housing, and the like. A front/reverse clutch and a high/low speed hydraulic clutch may be accommodated in the front housing, and a main speed hydraulic clutch may be accommodated in the transmission housing. The high/low speed hydraulic clutch and the main speed hydraulic clutch are clutches constituting the main transmission, and are separated from each other and may be connected to the third axis of the upper axis line, but in some cases, both may be formed on one second axis. may be

The oil outlet or drain port of the positive/reverse hydraulic valve device is connected to the oil inlet of the variable speed hydraulic valve device by an oil pipe, an accumulator may be connected to the oil pipe, and the positive/reverse hydraulic valve device may be located above the variable speed hydraulic valve device. there is.

The transmission of the present invention consists of a wet clutch for a front and rear transmission part and a main transmission part, and provides a simple and optimized structure for a front and rear hydraulic valve device and a variable speed hydraulic valve device for controlling each clutch, while providing one interface with mechanical and electronic types. It is possible to provide a transmission of a work vehicle that can be shared to improve product diversity.

The transmission of the present invention connects a forward/reverse hydraulic valve device and a variable speed hydraulic valve device with a hydraulic clutch, but can achieve both shaft support and oil injection with one support member.

The transmission of the present invention can connect the forward/reverse hydraulic valve device and the variable speed hydraulic valve device with one hydraulic pump, and even if one hydraulic pump is used, the control pressure of oil can be stably maintained in the variable speed hydraulic valve device located relatively downstream. there is.

The transmission of the present invention arranges the forward and reverse hydraulic valve device on the left side of the transmission to facilitate the connection and wiring between the clutch pedal and the forward and reverse section, and the shift hydraulic valve device is placed on the right side of the transmission to operate the main gear lever. Accordingly, wiring and the like can be easily performed.

1 is a view for explaining a transmission and a work vehicle including the transmission according to one embodiment of the present invention.
FIG. 2 is a diagram for explaining a power transmission structure of the work vehicle of FIG. 1 .
3 is a view for explaining the internal structure of the transmission of FIG. 1;
Figure 4 is a view for explaining the assembly process of the transmission of Figure 1;
5 is a view for explaining a transmission and hydraulic valve device according to an embodiment of the present invention.
Figure 6 is a view for explaining the connection of the hydraulic valve device in the transmission of Figure 5;
7 is a view for explaining a support member of a transmission according to an embodiment of the present invention.
8 is a view for explaining the connection between the hydraulic valve device of FIG. 7 and a support member.
9 is a diagram for explaining a variable speed hydraulic valve device according to an embodiment of the present invention.
10 is a diagram for explaining a hydraulic circuit of a transmission according to an embodiment of the present invention.
11 is a diagram for explaining an electronically controlled forward/reverse hydraulic valve device in a transmission according to an embodiment of the present invention.
12 is a diagram for explaining a mechanically controlled forward/reverse hydraulic valve device in a transmission according to an embodiment of the present invention.
13 is a diagram for explaining a hydraulic circuit in the case of installing a mechanically controlled forward/reverse hydraulic valve device in a transmission according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in the present description, the same numbers refer to substantially the same elements, and under the above rules, contents described in other drawings may be cited and described, and contents determined to be obvious to those skilled in the art or repeated contents may be omitted.

1 is a view for explaining a transmission and a work vehicle including the same according to an embodiment of the present invention, FIG. 2 is a view for explaining a power transmission structure of the work vehicle of FIG. 1, and FIG. 3 is a transmission of FIG. 1 It is a view for explaining the internal structure of, and FIG. 4 is a view for explaining the assembly process of the transmission of FIG.

1 to 4 , the work vehicle 100 according to the present embodiment includes a driving source 110, a rear wheel or first driving wheel 120, a front wheel or second driving wheel 130, a user driving unit 200 ), a transmission 300, a drive extraction device 400, a variable speed hydraulic valve device 500 for shifting, a PTO hydraulic pump device 600, and a PTO device 700.

A driving source 110 such as an engine generates power, and the power from the driving source 110 is shifted or controlled through the transmission 300 and can be used for driving or for work other than driving.

The transmission 300 may transmit all or part of the power transmitted from the driving source 110 to the first driving wheel 120 or the second driving wheel 130 for driving, and the power for work other than driving is the PTO. It can be delivered to the device 700. The power transmitted to the PTO device 700 can be transmitted without shifting from the drive source 110, which is an engine, and the drive source 110 generates maximum or optimal torque at 540 rpm, 1000 rpm or rotation proportional to the driving speed. You can rotate in GSP. Shifting within the PTO device 700 may be performed through a first shift control unit 735 using a shift clutch or the like.

To this end, the PTO device 700 may include a first power transmission unit 730 for multi-stage independent shifting. The first power transmission unit 730 may directly receive power from the drive source 110 regardless of the rotation direction of the forward/reverse unit 310 and the speed change by the main transmission unit 320, and is connected through the PTO clutch 720. Power may be shifted and transmitted to the PTO output shaft 710 .

The user driving unit 200 may include a driver's seat 210, a steering wheel 220, a clutch pedal 230, a forward and backward control unit 240, a main gear control unit 250, and a sub-shift control unit 260. The user can control the driving direction of the work vehicle 100 through the steering wheel 220 and the like, can control the rotational direction of the drive wheel through the forward and backward control unit 240, and the main gear control unit 250 and A shift stage or a shift range may be controlled through the shift control unit 260 .

The clutch pedal 230 may be located on the left under the steering wheel 220, the brake pedal may be provided on the right, and the parking brake 280 may be provided under the driver's seat 210. The brake pedal may be connected to a valve of a hydraulically operated brake device, and may operate the first brake 140 according to the operation of the brake pedal.

In this embodiment, the user driver 200 may be provided in an exposed form, but may include a cabin 270 in some cases.

The forward and reverse control unit 240 may proportionally control the hydraulic pressure applied to the forward and reverse unit 310 through the forward and reverse hydraulic valve device 800, and the main gear control unit 250 or the sub-shift control unit 260 is a shift hydraulic valve device The hydraulic pressure applied to the high/low speed hydraulic clutch 330, the main speed clutch 340, etc. may be proportionally controlled through (500). In this process, a hydraulic, electric, or manual operation method may be used for forward/reverse switching and transmission control.

Power passing through the transmission 300 may be transmitted to the rear wheels, that is, the first driving wheels 120 through the first differential 360 . In some cases, some power may be extracted to the front wheel output shaft 410 through the drive extraction device 400 and transmitted to the front wheels, that is, the second driving wheel 130 . When the second drive wheel 130 receives power like the first drive wheel 120 through the drive extractor 400, the work vehicle 100 can drive in a 4-wheel mode, and the 4-wheel mode can be operated on rough terrain or It can be usefully applied to moving the work vehicle 100 in a rice field or field or towing a high load. However, when driving on a general road, etc., it may be more efficient to drive in a 2-wheel mode rather than a 4-wheel mode. It is possible to switch to a two-wheeled mode in which the wheel 130 rotates passively.

A first brake 140 may be mounted between the first differential 360 and the first driving wheel 120, and the first brake 140 controls rotation of the first driving wheel 120, which mainly contributes to driving. By restraining, the work vehicle 100 can be stopped. For reference, pedals for operating the first brake 140 may be provided to the user driver 200 and may be provided on one side or both sides of the driver's seat.

Power from the engine may be connected to the first driving wheel 120, the second driving wheel 130, or the PTO device 700 through the transmission 300, and the inside of the transmission 300 includes a forward and reverse unit 310 , A main transmission unit 320, a secondary transmission unit 350, a first differential 360, and the like may be provided.

Referring to FIG. 2 , power from the drive source 110 may be transmitted to the forward/reverse unit 310 through the first shaft S1, and may be applied for forward or reverse movement through the forward/reverse unit 310. The rotation set in the direction by 310 may be transmitted to the peripheral part 320 through the lower second shaft S2.

The main transmission unit 320 may include a high/low speed hydraulic clutch 330 and a main transmission hydraulic clutch 340 adjustable from 1st to 4th gear. The auxiliary transmission unit 350 may additionally adjust the shift range to the rotation shifted by the main transmission unit 320, and control the A, B, C or Cr (creep) ranges using the shift clutch as shown. can

In this embodiment, the high/low speed hydraulic clutch 330 and the main speed hydraulic clutch 340 are hydraulic clutches using friction plates, and may be controlled by the shift hydraulic valve device 500 for shifting, and may be controlled by the auxiliary shifting unit ( The shift clutch of 350) can be operated electrically or hydraulically. The transmission 300 according to this embodiment can be shifted to 24 steps or 32 steps by the main transmission part 320 and the auxiliary transmission part 350.

Some of the power from the engine may be transmitted to the PTO device 700 without passing through the forward/reverse part 310 or the main transmission part 320, and the power transmitted to the PTO device 700 may be transferred to the PTO hydraulic pump device 600. ), it is possible to drive a tandem pump or the like, and to provide power for shifting the PTO device 700 or supplying lubricating oil. In the PTO device 700, power may be transmitted to the PTO output shaft 710 through the PTO clutch 720 and the first power transmission unit 730.

In addition, some of the power from the engine may be transmitted to the PTO device 700 via the forward/reverse part 310 or the main transmission part 320, and the power transmitted to the PTO device 700 in this way is proportional to the driving speed. Alternatively, it may be transmitted at a corresponding rotational speed, and may be used for work sensitive to vehicle speed, such as rice planting. Power for synchronizing the vehicle speed may be transmitted to the PTO output shaft 710 through another power transmission unit in the PTO device 700 .

A gear for extracting power to the outside may be mounted on a shaft on which a shift clutch is mounted in the auxiliary transmission unit 350, and a drive extraction gear 370 is provided at an end thereof. The drive extraction gear 370 may be partially exposed from the housing of the transmission 300, and the drive extraction device 400 may be mounted in an area where the drive extraction gear 370 is exposed.

3 and 4, the inside of the transmission 300 may be provided by assembling the front housing 302, the transmission housing 304, and the differential housing from the front. In this embodiment, the front housing 302 may accommodate the high/low speed hydraulic clutch 330 among the front/reverse part 310 and the main transmission part 320, and the transmission housing 304 includes the main transmission hydraulic clutch 340 and A sub-shift hydraulic clutch may be accommodated.

In the front housing 302, the forward/reverse part 310 is located on the upper first shaft S1, and the high/low speed hydraulic clutch 330 may be provided on the lower second shaft S2. The shaft S1 and the second shaft S2 may be supported by the shaft support member 900 within the front housing 302 .

Even within the mission housing 304, the main gear hydraulic clutch 340 and the auxiliary transmission 350 may be provided at the lower part, and the inner shaft Si and the surroundings may transmit the driving of the engine to the PTO device 700 at the upper part. A third shaft S3 capable of transmitting rotation of the inner part 320 from the high/low speed hydraulic clutch 330 to the main hydraulic clutch 340 may be provided.

The third shaft S3 may be formed by combining a part S3 - 1 of the third shaft in the front housing 302 and a part S3 - 2 of the third shaft in the mission housing 304 . A portion of the second shaft S2-1 equipped with the main transmission hydraulic clutch 340 is located at the lower portion, but may receive rotation of the second shaft S2 in front through the third shaft S3.

As the front housing 302 and the mission housing 304 are coupled, the first axis S1 of the forward and reverse portion 310 accommodated inside the front housing 302 and the inner axis Si accommodated in the mission housing 304 are They can be axially coupled to each other.

As the front housing 302 and the mission housing 304 are mutually assembled, the front and rear housings and the front and rear internal parts may be interconnected.

Figure 5 is a view for explaining a transmission and a hydraulic valve device according to an embodiment of the present invention, Figure 6 is a view for explaining the connection of the hydraulic valve device in the transmission of Figure 5, Figure 7 is one of the present invention A view for explaining a support member of a transmission according to an embodiment, FIG. 8 is a view for explaining a connection between the hydraulic valve device of FIG. 7 and a support member, and FIG. 9 is a shift hydraulic valve according to an embodiment of the present invention. It is a diagram for explaining an apparatus, and FIG. 10 is a diagram for explaining a hydraulic circuit of a transmission according to an embodiment of the present invention.

5 to 10, a forward and reverse hydraulic valve device 800 is mounted on the left wall of the front housing 302 of the transmission 300, and a shift hydraulic valve device 500 for shifting is mounted on the right wall. there is. The shift hydraulic valve device 500 is mounted on the transmission 300 to supply oil to the main transmission part 320, and in this embodiment, the high/low speed hydraulic clutch 330 and the main speed hydraulic clutch 340 respectively A controlled hydraulic pressure can be supplied to the hydraulic system.

The shift hydraulic valve device 500 may include a shift valve block 510, an accumulator 520, and six shift control valves 530, and an oil inlet 512 is formed at an upper portion of the shift valve block 510. And, a valve mounting groove 514 for mounting the shift control valve 530 may be formed at a lower portion facing the oil inlet 512 . The oil inlet 512 and the valve mounting groove 514 may communicate with each other, and the valve mounting groove 514 is connected one-to-one to the oil outlet 516 to form a high/low speed hydraulic clutch 330 and a main speed hydraulic clutch. 340, respectively.

The shift hydraulic valve device 500 according to the present embodiment may be supplied with oil that has passed through the forward/reverse hydraulic valve device 800 located on the opposite side of the transmission 300 . The variable speed hydraulic valve device 500 may be supplied with oil indirectly through the normal/reverse hydraulic valve device 800 instead of being directly supplied with oil from the hydraulic pump 890 .

Accordingly, the variable speed hydraulic valve device 500 according to the present embodiment may include an accumulator 520 for stable oil supply, and the accumulator 520 may include the forward/reverse hydraulic valve device 800, which is one of other hydraulic devices, and the oil It may be located between the inlets 512 .

In this embodiment, the forward/reverse hydraulic valve device 800 may be mounted adjacent to the first shaft S1 on the left wall of the front housing 302, and is fixed at a relatively higher position than the variable speed hydraulic valve device 500. It can be.

The forward and reverse hydraulic valve device 800 includes a forward and reverse valve block 810 mounted on the left wall of the front housing 302, forward and reverse control valves 820 and 822 mounted on the rear side of the forward and reverse valve block 810, and forward and reverse control valves ( A first pipe 860 connecting 820 and 822 and the shaft support member 900 may be included.

The variable speed hydraulic valve device 500 according to the present embodiment is connected to the forward/reverse hydraulic valve device 800 through a connecting pipe 895 passing through the lower portion of the transmission, and the accumulator 520 is connected to the connecting pipe 895. has been The forward/reverse hydraulic valve device 800 may receive oil from a hydraulic pump 890 inside the transmission 300 .

As shown in FIG. 10 , the oil supplied from the hydraulic pump 890 may be supplied as a kind of working oil to the forward/reverse part 310 and the shift hydraulic valve device 500 through the forward/reverse hydraulic valve device 800, and the shift hydraulic valve The oil supplied to the device 500 is supplied to the hydraulic clutches 330 and 340 of the peripheral transmission 320 and other hydraulic devices, for example, the clutch of the drive extraction device 400 and the auto lock of the differential 360. , can be reconnected to the PTO device 700, etc.

Referring to FIG. 9 , six shift control valves 530 may be mounted on the lower part of the shift valve block 510, and the six shift control valves 530 are proportional control valves or on-off control valves, and the shift valve block It can be modularized together with 510 and mounted on the transmission 300. In this embodiment, the oil inlet 512 is formed at the top and the shift control valve 530 is mounted at the bottom to prevent abnormal operation even when air or water vapor is generated in the oil.

In addition, a pressure sensor 540 is mounted on each shift control valve 530 to sense pressure feedback from the hydraulic clutch.

The oil outlet 516 may further include a second pipe 560 coupled to the valve block, and the second pipe 560 may be connected to the shaft support member 900 from the inside of the transmission 300, and may be connected to the outside of the transmission 300. is connected to the oil outlet 516 of the shift valve block 510 to function as a passage through which oil is connected from the outside to the inside.

Shaft support member 900 is mounted in the front housing 302, provides a bearing capable of supporting the first shaft (S1) in the upper part, and provides a bearing capable of supporting the second shaft (S2) in the lower part. to provide. Accordingly, the first shaft S1 and the second shaft S2 and other hydraulic clutches 310 and 330 may be supported by the shaft support member 900 . Figure 7 (b) is a cross-section ii 'in (a), the shaft support member 900 is fixed to the inside of the front housing 302, the first shaft (S1) and the upper and lower parts Provides a bearing capable of supporting two axes (S2), the first pipe 860 and the second pipe 560 are formed on the side wall facing each other, the first pipe 860 is the first axis (S1) It can be seen that it is formed on the upper part corresponding to and the second pipe 560 is located on the lower part corresponding to the second axis S2.

At the same time, oil passages 912 and 914 supplied from the shift hydraulic valve device 500 may be formed inside the shaft support member 900, and the oil supplied from the forward/reverse hydraulic valve device 800 may be supplied to the first A passage for guiding the shaft S1 to the passage 916-1 can also be formed. 7 and 8, oil passages 912, 914, and 916 for delivering oil through pipes 560 and 860 are formed in the shaft support member 900, and passages 912 and 916 facing each other are formed. 914) may be formed inside the same support member 900, although the valve devices connected to each other are different. In addition, a flow path 916-1 communicating with the forward and reverse hydraulic valve device 800 is formed in the first shaft S1 so that the forward and reverse clutch 310 operates according to the operation of the forward and reverse control valves 820 and 822. can do.

Similar to the flow path 916-1 of the first shaft S1, a flow path communicating with the shift hydraulic valve device 500 may be formed in the second shaft S2, and the flow path of the shaft support member 900 ( 912 can be extended rearward to be connected to the desired high/low speed hydraulic clutch 330, and the desired shift clutch 330 can be operated according to the operation of the shift control valve 530.

In this embodiment, the flow path connected to the forward/reverse clutch 310 around the shaft support member 900 extends forward along the first axis S1, and the flow path connected to the high/low speed hydraulic clutch 330 is the first. It may extend backward along two axes (S2).

When the shift control valve 530 is opened, the pressure sensor 540 may form the same pressure as the inside of the hydraulic clutches 330 and 340, and accordingly, the pressure inside the hydraulic clutches 330 and 340 may provide feedback whether or not the pressure inside the hydraulic clutches 330 and 340 is within a normal range. can receive

A plurality of through-holes corresponding to each second pipe 560 may be formed on a wall surface of the transmission 300 to allow the second pipe 560 to pass therethrough. The through-holes may be integrated into one and formed in a size that allows all the pipes to pass through, but in order to stably support and guide the second pipe 560, the through-hole according to the present embodiment supports each second pipe 560. It can be formed separately so that it can be done.

An interface for mounting and fixing the shift hydraulic valve device 500 may be provided on the right side of the transmission 300, and an operator may insert a pipe through a through-hole at the corresponding interface, and the shift hydraulic valve device 500 The shift valve block 510 of may be mounted on the transmission 300.

Oil connection holes 552 , 554 , and 556 that can be connected to other hydraulic devices may be formed in the shift valve block 510 . The oil connection holes 552, 554, and 556 may communicate with the oil inlet 512, and the oil introduced into the oil inlet 512 through the oil connection holes 552, 554, and 556 forms the same hydraulic pressure, The shift hydraulic valve device 500 may have a manifold structure for resupplying oil or forming hydraulic pressure to other hydraulic devices of the work vehicle.

As shown in (b) of FIG. 9, the oil connection holes 552, 554, and 556 are a pipe 552-1 connected to the drive extraction device 400 for front wheel drive, and a differential for automatic differential lock ( 360), a pipe 554-1 connected to the hydraulic clutch 720 of the PTO device 700, and the like. In addition, the oil connection hole 558 for supplying lubricating oil may also be connected to a lubricating oil supply pipe 558-1 for supplying lubricating oil supplied from the power steering device through the cooler to the PTO device 700. Here, the lubricating oil may be supplied to the shift valve block 510 through a path different from the oil inlet 512 .

In this embodiment, since the relief valve 830 is provided in the forward/reverse hydraulic valve device 800, the relief valve may be omitted in the shift hydraulic valve device 500. However, when the normal/reverse hydraulic valve device is of a mechanical type, a relief valve may be formed in the right-side shift hydraulic valve device. That is, the relief valve may be mounted on at least one of the forward/reverse hydraulic valve device and the variable speed hydraulic valve device.

11 is a view for explaining an electronically controlled normal and reverse hydraulic valve device in a transmission according to an embodiment of the present invention, and FIG. 12 is a mechanically controlled normal and reverse hydraulic valve device in a transmission according to an embodiment of the present invention. It is a drawing for explanation.

Referring to FIG. 11, the electronically controlled forward/reverse hydraulic valve device 800 includes a forward/reverse valve block 810 mounted on the left wall of the front housing, a forward/reverse control valve 820 mounted on the rear side of the forward/reverse valve block 810, It may include a lubricating oil shutoff valve 830, and an oil inlet 842 through which oil flows in, an oil supply port 844 for controlling the oil pressure of the forward/reverse clutch, and an oil outlet 846 are formed on the inner surface, there is.

In addition, referring to FIG. 12, the mechanical control type forward and reverse hydraulic valve device 800' also includes a forward and reverse valve block 810' and a direction change control spool 820 connected to a forward and reverse control lever 822' for switching forward and backward. , a modulation valve 830 connected to the clutch lever 832' connected to the clutch pedal.

Like the aforementioned electronically controlled normal and reverse hydraulic valve device 800, the inner surface of the mechanically controlled normal and reverse hydraulic valve device 800' also has an oil inlet 842', an oil supply port 844', and an oil outlet. 846' is formed identically, and its position, shape, size, etc. are also formed identically for compatibility.

In this way, it can be mounted on the housing with the same interface regardless of the electronic control method or the mechanical control method, and the oil inlet and oil outlet from the oil pump can perform the same function while maintaining the same interface.

In addition, both the oil outlets 846 and 846' are formed at high positions, and are located at higher positions than other internal parts such as valves and sensors of the forward and reverse hydraulic valve devices 800 and 800', and are formed higher than the oil level of the transmission. It can be.

13 is a diagram for explaining a hydraulic circuit when a mechanically controlled forward and reverse hydraulic valve device is installed in a transmission according to an embodiment of the present invention.

Referring to FIG. 13 , it can be seen that the hydraulic circuit of FIG. 10 perfectly corresponds to the installation of the mechanically controlled forward/reverse hydraulic valve device 800'.

Although the internal configurations of the direction conversion control spool 820' connected to the control lever 822' and the modulation valve 830' connected to the clutch lever 832' connected to the clutch pedal are different, The connected forward/reverse valve block 810', oil inlet 842', oil supply port 844' and oil outlet are interchangeable.

In fact, it can be confirmed that the connection between the oil inlet 842 and the oil supply port 844 of FIG. 10 is equally applied to the oil inlet 842' and the oil supply port 844' of FIG. 13 . Of course, in FIGS. 11 and 12, the oil outlets 846 and 846' correspond to the same positions.

As described above, although it has been described with reference to the preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: work vehicle 110: driving source
140: first brake 200: user driving unit
300: transmission 500: variable speed hydraulic valve device
510: valve block 520: accumulator
530: hydraulic control valve 540: pressure sensor
600: PTO hydraulic pump device 700: PTO device
800, 800': forward and reverse hydraulic valve unit 810, 810': forward and reverse valve block
820: forward and reverse control valve 822': forward and reverse control lever

Claims (4)

In the transmission of a work vehicle including a forward and reverse clutch for forward and backward conversion,
A positive/reverse hydraulic valve device mounted on the left wall of the transmission housing to perform hydraulic control for forward/reverse switching and wet main clutch functions,
The forward and reverse hydraulic valve device is provided in a mechanical control method or an electronic control method,
The transmission of the work vehicle, characterized in that the forward and reverse hydraulic valve device provided by a mechanical control method or an electronic control method has a compatible interface with the housing.
According to claim 1,
The transmission of the work vehicle, characterized in that the forward and reverse hydraulic valve device is provided installed in the housing.
According to claim 1,
The forward and reverse hydraulic valve device is provided as an independent package and mounted on the housing,
The transmission of the work vehicle, characterized in that the oil inlet, oil supply port and oil outlet formed in the forward and reverse valve block are formed at the same location to be compatible with a mechanical control method or an electronic control method.
According to claim 1,
The transmission of the work vehicle, characterized in that the oil outlet of the positive and reverse hydraulic valve device is located at a higher position than the oil level in the transmission and other internal parts of the positive and reverse hydraulic valve device.

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