JPH0744500Y2 - Mission device for traveling work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a transmission device suitable for replacing a hydraulic power transmission device in a transmission of a relatively small traveling work vehicle such as a mower tractor.

Conventional technology As a transmission for small traveling work vehicles, the transmission case of a transaxle type mechanical transmission equipped with left and right drive wheel shafts is further equipped with a PTO shaft for extracting work machine drive force, A hydraulic transmission device is mounted on the end face on the input end side of the above-mentioned motion case to change gears by volume control of a variable displacement hydraulic pump, and the left and right drives from the motor shaft of the hydraulic transmission device in the above-mentioned motion case. PTO that transmits from the transmission system transmission mechanism that transmits to the wheel shaft and the pump shaft of the hydraulic transmission to the PTO shaft
A system in which a system transmission mechanism is incorporated is known as disclosed in, for example, U.S. Pat. No. 4,579,183 and Japanese Utility Model Publication No. 61-81427.

In a work vehicle equipped with a transmission of the above structure that is positioned at one end of the vehicle body between the left and right drive wheels, the engine is installed at the other end of the vehicle body, and the passenger seat is located above the transmission. Is located in. In the hydraulic transmission, the hydraulic pump and the hydraulic motor are arranged vertically, but since the hydraulic transmission can be relatively small, the outside of the end face of the mesh case is opened below the hydraulic transmission, By utilizing it, the left and right wheels on the engine side can be driven as needed from the inside of the mission case, and the wheel drive force extraction shaft and the Mitto PTO shaft for extracting the drive force of the working machine such as the Mt. It is generally provided so as to project from the lower portion of the mesh case to the outside of the end face. Therefore, as the PTO shaft, the rear PTO that protrudes from the mission case toward the fuselage end
A shaft or front PTO shaft and the above-mentioned mixed PTO shaft are generally provided. The traveling system transmission in the transmission case naturally includes a differential device for the left and right driving wheels, and a left and right brake and a final reduction mechanism are provided between the differential device and the left and right driving wheel shafts. It is usually provided.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention In the above-mentioned work vehicle transmission, there is a demand for a transmission provided with a mechanical transmission instead of the hydraulic transmission. In other words, the mechanical transmission is disadvantageous in that it makes a stepless shift than the hydraulic transmission that obtains a continuously variable shift, and the cost of the device itself is not so different from each other. This is because the device is certainly expensive only for the required additional hydraulic equipment, and the mechanical transmission is more advantageous in terms of maintenance.

However, in reality, such a mesh device is not provided. That is, there are the following problems to be overcome.

That is, basically, it is economically disadvantageous unless the transmission case provided with a hydraulic transmission device and the transmission provided with a transmission device replacing the hydraulic transmission device have the same structure on the side of the case. The drive shaft of the PTO system corresponding to the pump shaft of the transmission device and the speed change shaft of the traveling system corresponding to the motor shaft of the hydraulic transmission device and capable of outputting to the inside of the mesh case, the pump shaft and the motor of the transmission device. It must be provided in the same position as the axis and occupy. The pump shaft receives input conduction from the engine, and is arranged at a substantially central position in the lateral width direction of the hydraulic transmission so that the engine, which is a heavy object, can be arranged at the center in the lateral direction of the machine. The motor shaft also has a relatively large lateral width in the differential case, and if it is arranged so as to be offset to one side, the arrangement of the left and right brakes and the left and right reduction mechanisms will be restricted. The transmission device is arranged substantially at the center in the width direction. Since a mechanical transmission requires a clutch for gear shifting operation, a transmission equipped with a mechanical transmission is provided with a drive shaft connected to the drive shaft of the PTO system via the clutch. Since the transmission system of the traveling system is arranged between the speed changing shafts, the number of shafts is increased in this way, and the driving shaft and the speed changing shaft must be arranged in the same manner as the pump shaft and the motor shaft. .

Next, in order to enable a transmission equipped with a mechanical transmission to be handled in the same manner as a hydraulic transmission, the transmission must be equipped with a gear shift operation mechanism for the mechanical transmission in addition to the clutch described above. I won't. In addition, the clutch and the gear shift operation mechanism need to have an operation portion, that is, a clutch pedal or a gear shift lever, at a position where the operator of the passenger seat can easily operate. Even if the operating portion itself is provided at a position where it can be easily operated, it is of course not desirable that the operating mechanism is complicated by that.

The present invention solves such a problem to meet the above-mentioned demand.

Technical measures taken to solve the problems Therefore, the present invention has taken the following technical measures as illustrated in FIGS. 1-3.

That is, in the upper portion of the case lid 2 that covers the opening at one end in the front-rear direction of the movement case 1, a cylindrical shaft support portion 3 and an annular shape that are disposed substantially at the center in the width direction and project in a direction away from the movement case 1. The clutch supporting portion 4 and the fork shaft end accommodating portion 5 having an upper end open box-like shape and arranged on the upper side of the shaft supporting portion 3 by shifting to one end side in the lateral width direction are integrally formed to be connected to each other. The hollow transmission shaft 7 projecting into the clutch accommodating part 4 and the mesh case 1 is supported by the part 3, and the input end 6a is protruded from the cover 8 covering the opening end of the clutch accommodating part 4 and the output end 6b. A drive shaft 6 projecting outside the mesh case 1 is provided inside the mesh case 1 through the hollow transmission shaft 7, and a clutch 9 for connecting and disconnecting the drive shaft 6 and the hollow transmission shaft 7 is provided. The above Kratu It is provided in the housing unit 4.

Further, a drive shaft 10 which is biased in a direction opposite to the fork shaft end receiving portion 5 when viewed in the lateral direction of the motion case 1 is provided in the motion case 1 at a level lower than the drive shaft 6. The drive shaft 10 is connected to the hollow transmission shaft 7 by gears 11 and 12, and a transmission shaft 13 arranged at a level lower than the drive shaft 10 at a substantially central position in the width direction of the case is a case. 1, an output end 13a of the speed change shaft 13 is provided so as to protrude from the mesh case 1 in the same direction as the output end 6b of the drive shaft 6, and the speed change shaft is provided between the drive shaft 10 and the speed change shaft 13 described above. 13 shift gears on top
A mechanical transmission 14 including 15 is provided.

Further, a fork shaft 16 having one end projecting into the fork shaft end receiving portion 5 is disposed in a mesh case 1 at a level above the driving shaft 6 and supported so as to be slidably displaced. A shift lever 17 supported by a cover 19 that covers the open end of the fork shaft end housing 5 is engaged with the fork shaft 16 within the fork shaft end housing 5, and a shift fork 18 attached to the fork shaft 16 is mounted. Shift shift hardware on the shift shaft 13 described above
Engage with 15.

Operation FIG. 1 shows a mesh case 21 disclosed in the above-mentioned U.S. Pat. No. 4,579,183 (hereinafter referred to as a "second mesh case" to avoid confusion with the mesh case 1 of the mesh device according to the present invention. ), That is, the left and right drive wheel axles
22 (Figs. 4 and 6) and PTO shafts 23 and 24 are provided, and a transmission system transmission mechanism and a PTO system transmission mechanism are installed on the input end side end face of the second transmission case 21 according to the present invention. FIG. 4 is a vertical cross-sectional side view in a state where the mission device MA is mounted, and FIG. 4 shows a side view of a mower tractor equipped with the transmission shown in FIG. The mission device MA of the present invention is suitable for use in a traveling work vehicle as shown in FIGS. 1 and 4, and as shown in FIG. 1, the output end 13a of the transmission shaft 13 has a second mission case. The drive system drive shaft 25 in 21 is connected by gears 26 and 27,
The output end 6b of the PTO system transmission shaft 2 in the second mission case 21 is
8 is connected by a coupling 29. Fourth
As shown in the figure, the input end 6a of the drive shaft 6 is connected to an engine 30 installed on the machine body on the opposite side of the transmission via a transmission shaft 31 having flexible joints at both ends.

In the mission device MA arranged in the portion where the hydraulic power transmission device has been arranged up to now, the shift lever 17 protruding from the fork shaft end housing portion 4 which is arranged to be shifted to one side as shown in FIG. 2 The clutch pedal 33 for operating the clutch 9 in the clutch accommodating portion 4 located on the front side of the passenger seat 32 installed above the mission case 21 and at the lower front portion of the passenger seat 32 is The clutch accommodating portion 4 can be directly attached to an operation shaft projecting from one side wall of the clutch accommodating portion 4 and can be disposed at a front lower position of the passenger seat 32. The mechanical transmission 14 is used to change the vehicle speed. The clutch pedal 33 is depressed to cut off the clutch 9, and the gear shift lever 17 shifts the gear.

The output end 13a of the speed change shaft 13 conducts output to the traveling transmission mechanism in the second transmission case 21, and the output end 6b of the driving shaft 6 outputs to the PTO transmission mechanism in the second transmission case 21. Conduct output.

Embodiment The illustrated embodiment relates to an example in which the present invention is implemented in a mower tractor having left and right rear wheels 35 as driving wheels. As shown in FIG. 4, an engine 30 is arranged in the front part of the body and a transmission is arranged in the rear part of the body. In addition, the mission case 1 is disposed on the front side, and the second mission case 21 is disposed on the rear side.

Between the front wheel 36, which is the steering wheel, and the rear wheel 35, which is the drive wheel, a Mitumount mower M is installed on the lower surface of the fuselage.
Of the PTO shafts 23, 24, the PTO shaft 23 is a rear PTO that extracts the driving force of a working machine such as a rotary cultivator connected to the rear part of the machine body.
Shaft, and PTO shaft 24 is a MTO PTO that extracts the driving force of the mower M.
Each is configured on a shaft. Below the mesh unit MA, from the second mesh case 21, the above-mentioned mesh PTO shaft 2
4 and the front wheel driving force output shaft 37 are projected. In FIG. 4, 38 is a front wheel drive force take-out shaft that rotates as necessary.
A transmission shaft for transmitting the driving force from 37 to the front wheels 36, and a transmission shaft 39 for transmitting the driving force from the mixed PTO shaft 24 to the gear box Ma of the mower M.

In FIGS. 1 and 2, a cover 41 is attached to the front surface of a second mesh case 21 having a front end opened, and the mesh case 1 covers the flange portion 1a at the rear end of the mesh case 41.
Along with the upper half of the cover 41, the cover 41 and the bolt 41 are mounted on the second mesh case 21. In FIG. 1-3, the case lid 2 is provided with a bolt insertion hole 43 at the projecting edge portion of the outer peripheral end.
And corresponding screw holes 44 are provided on the projecting edge of the outer peripheral end of the case 1, and the case cover 2 is fastened to the case 1 by bolts 45 using these holes 43 and 44. ing. In FIGS. 1 and 3, reference numerals 46 and 47 denote reinforcing ribs provided between the clutch housing 4 and the outer surface of the case lid 2 and between the clutch housing 4 and the fork shaft end housing 5, respectively.

In FIG. 1, the hollow transmission shaft 7 is supported by the shaft support portion 3 via a pair of ball bearings 48. The clutch 9 is of a well-known friction plate type that engages a friction disk interposed between a drive wheel 49 fixedly installed on the driving shaft 6 and a driven wheel 50 fixedly installed on the hollow transmission shaft 7 by a spring force. The release bearing assembly on the hollow transmission shaft 7 is pushed by the shifter 51a on the operation shaft 51 provided inside and outside the clutch accommodating portion 4 to perform the cutting operation. The clutch pedal 33 shown in FIG. 4 is attached to the outer end of the operating shaft 51.

In FIGS. 1 and 2, the drive shaft 6 penetrates the case lid 2 and the mesh case 1 at the center position in the lateral width direction,
Further, the speed change shaft 13 is slightly biased to the drive shaft 10 side from the center position. The mechanical transmission 14 described above includes five gears 53F ₁ , 53F ₂ , 53F ₃ , 53F fixedly installed on the drive shaft 10.
₄ and 53R and 5 gears 54F ₁ and 54 that are loosely fitted on the transmission shaft 13
F ₂ , 54F ₃ , 54F ₄ , 54R. Forward gear 53F _1-
53F ₄ and 54F ₁ -54F ₄ is directly engaged respectively, the gear 53R and 54R of the reverse gear idler shaft as shown in Figure 2
It is meshed with an idler gear 55 on 55a. The shift shift hardware 15 is configured as a shift collar that selectively connects the gears 54F ₁ -54R to the shift shaft 13, and three shift shift hardwares 15 are provided.

Correspondingly, the fork shaft 16 and shift fork 18
The shift forks 18 are fixed to the respective fork shafts 16 by the pins 56. The fork shaft 16 is supported by a bearing hole 57 penetrating the rear wall of the fork shaft end accommodation part 5 and a one-blind bearing hole 58 on the inner surface projection of the top wall of the migration case 1. In each of them, the engaging metal piece 59 is fixed by the pin 60. The speed change lever 17 is supported by the cover 19 via a ball 61, and is operated in the direction of the arrow A in FIG. When operated in the B direction, each fork shaft 16 is slidably displaced, and the shift fork 18 and the shift collar 15 are thereby displaced to obtain a gear shift.

The structure of the transmission mechanism provided in the second transmission case 21 is exactly the same as that disclosed in the above-mentioned US Pat. No. 4,579,183.

That is, the transmission mechanism of the traveling system is, as shown in FIGS. 1 and 6, transmitted from the transmission shaft output end 13a to the gear 26, as described above.
27 Transmission shaft 25 receiving transmission and sub-transmission shaft 63 arranged in parallel with it
A mechanical auxiliary transmission 64 disposed between the auxiliary transmission and the auxiliary transmission.
63 A differential gear 67 having a large bevel gear 66 meshed with a small bevel gear 65 at the rear end as an input gear, and left and right friction multi-plate type brakes for braking the left and right output shafts 68 of the differential gear 67 69, and the left and right planetary gear type final reduction mechanism 70 disposed between the left and right output shafts 68 and the left and right drive wheel shafts 22 described above.

As shown in FIG. 1, the auxiliary transmission 64 has transmission gears 27, 71 rows and transmission gears 72, 73 rows, and two shifts are performed by a shift collar 74 on the auxiliary transmission shaft 63. The sub-transmission shaft 63 is transmitted to the differential device 67, and is also transmitted to the front wheel drive force output shaft 37 via gears 75 and 76 and a front wheel drive clutch 77. As shown in FIG. 6, the differential device 67 is arranged at the center in the lateral width direction of the second mesh case 21 so as not to restrict the arrangement of the left and right brakes 69 and the left and right final reduction gear mechanisms 70. The differential 67 is provided with a defrost clutch 78.

As shown in FIGS. 1 and 5, the transmission mechanism of the PTO system in the second transmission case 21 has a transmission shaft 28 which receives power from the drive shaft output end 6b and a clutch which is arranged in parallel with the transmission shaft 28, respectively. A shaft 80 and an intermediate shaft 81 are provided. Clutch shaft 80
A hydraulic multi-plate PTO clutch 84 is provided above which selectively connects a gear 83, which is rotated by a gear 82 on the transmission shaft 28, to the clutch shaft 80. Two gears 85 and 86 are loosely fitted to the clutch shaft 80 on the front side of the PTO clutch 84. The gear 85 meshes with the gear 87 on the intermediate shaft 81,
A rear PTO transmission 88 is arranged between 81 and the rear PTO shaft 23. In addition, the gear 86 is connected via an idler gear (not shown)
It is connected to the gear 89 on the PTO shaft 24. Between the gears 85 and 86, both gears 85 and 86 should be on the clutch shaft 80.
The position where it is connected to and either gear 85 or 86
There is provided a PTO switching clutch 90 having a clutch sleeve 90a that is shifted to a position where it is coupled to the clutch shaft 80.

At the rear end side of the clutch shaft 80, when the clutch sleep 90a is shifted and when the gear shift operation of the rear PTO transmission 88 is performed, the inertia for the working machine that brakes the clutch shaft 80 after cutting the PTO clutch 84 is cut. Anti-rotation brake 91
Is provided. The rear PTO transmission has transmission gears 92, 93 rows and transmission gears 94, 95 rows, and the shift collar 96 on the rear PTO shaft 23 is supposed to perform two-stage gear shifting.

The mower tractor shown in FIG. 4 is used for cutting the mower M while the vehicle is running, and is connected to the rear of the machine to form the rear PTO shaft 23.
It is used for various works such as simultaneous grass collection work by a grass collector driven more, and cultivation work by a rotary tiller connected to the rear part of the machine and driven by a rear PTO shaft 23. Stationary work is also possible, such as carrying out control work with a control machine that stops the vehicle and extracts the driving force from the rear PTO shaft 23.

When the vehicle is running, the transmission 14 of the transmission device MA shifts to four forward gears and one reverse gear, and the auxiliary transmission 64 in the second transmission case 21 can shift gears to two further gears. It is possible to shift gears between two speeds and two reverse speeds.
The clutch 9 that is cut off before the gear shifting operation of the transmission 14 is
It is also used for easy operation during gear shifting operation of the auxiliary transmission device 64.

Effect of the Invention In the mission device of the present invention, the driving shaft 6 is passed through the hollow transmission shaft 7 supported by the shaft supporting portion 3 at the center of the upper portion of the case lid 2 in the lateral width direction. 1, the transmission shaft 13 is located at a substantially center in the lateral width direction, and the transmission shaft 13 is arranged at a level lower than the drive shaft 10 arranged at a level lower than the driving shaft 6. Since it is located at the level in the lower part of 1 and approximately at the center in the width direction of the mesh case, the mesh device of the present invention is replaced by a hydraulic transmission device, and travels like the second mesh case 21 of the illustrated example. System and
Installed on the input side end surface of the transmission case that houses each PTO system transmission mechanism, and the input end of the drive shaft 6
While conducting input from the engine to 6a, from the output end 13a of the speed change shaft 13 to the traveling transmission mechanism, and from the output end 6b of the drive shaft 6 to the PTO transmission mechanism,
Each output can be conducted, but for that purpose, the following advantages are added.

That is, while the drive shaft 6 and the speed change shaft 13 are arranged at substantially the center position in the lateral width direction of the mesh case 1, the drive shaft 10 is offset to one side in the lateral width direction. Not only is it necessary to increase the inter-axis distance between the drive shaft 10 and the speed-changing shaft 13 without increasing the width or height and to provide a multi-speed gear train between them for obtaining a multi-speed gear change. FIG. 2 shows a shift fork 18 for shifting operation of the gear shift shift hardware 15, that is, a shift fork 18 whose lower half portion is expanded by engaging the gear shift shift hardware 15 in such a manner as to hold the gear shift shift hardware 15. As illustrated, the drive shaft 10 can be installed without difficulty by passing through a space that is largely opened laterally.

In order to position the driving shaft 6 substantially at the center in the width direction of the transmission case 1, the cylindrical shaft support portion 3 and the annular clutch accommodating portion 4 are formed substantially at the center of the upper portion of the case lid 2 in the width direction. Since the box-shaped fork shaft end housing portion 5 is formed to be offset in the lateral width direction, the gear shift lever 17 for engaging with the fork shaft 16 in the housing portion 5 is located on the front side of the vehicle passenger seat. That is, the operator faces the position most easily operated by the operator, and the clutch accommodating portion 4 projecting from the upper portion of the case lid 2 is used for cutting and operating the internal clutch 9 at the front lower position of the passenger seat. The clutch pedal can be provided at the one position on the lower front side of the passenger seat without interposing a special interlocking mechanism.

Since the gear shift operation mechanism up to the clutch 9 and the gear shift lever 17 is equipped in the transmission by utilizing the upper portion of the case lid 2, the transmission can be handled as a single unit like a hydraulic power transmission device and incorporated in the vehicle. .

[Brief description of drawings]

FIG. 1 is a partially developed vertical sectional side view of a main part of a mower tractor equipped with an embodiment of the present invention, and FIG. 2 is a partially omitted vertical sectional front view substantially along the line II-II in FIG. 3 is a schematic perspective view of one member, FIG. 4 is a partially cutaway schematic side view of the mower tractor, and FIG. 5 is a sectional view of FIG. Longitudinal side view, FIG. 6 shows VI-VI in FIG.
It is sectional drawing substantially along a line. 1 ... Mission case, 2 ... Case lid, 3 ... Shaft support, 4 ... Clutch housing, 5 ... Fork shaft end housing, 6 ... Driving shaft, 6a ... Input end, 6b ... … Output end, 7 …… Hollow transmission shaft, 8 …… Cover, 9 …… Clutch, 10 …… Drive shaft, 11,12 …… Gear, 13 …… Shift shaft, 13a
…… Output end, 14 …… Mechanical transmission, 15 …… Shift shift hardware, 16 …… Fork shaft, 17 …… Shift lever, 18
...... Shift fork, 19 ...... Cover, 21 ...... Second shift case, 22 ...... Drive wheel shaft, 23 ...... Rear PTO shaft, 24
…… Mitsu PTO shaft, 30 …… Engine, 33 …… Clutch pedal, MA …… Mission device.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical shaft support, which is arranged at an approximately central portion in the lateral width direction and which protrudes in a direction away from the case 1, at an upper portion of a case cover 2 which covers an opening at one end in the front-rear direction of the case 1. The portion 3 and the annular clutch accommodating portion 4 and the fork-shaped shaft end accommodating portion 5 having an upper end open box-like shape and arranged on the upper side of the shaft supporting portion 3 by being shifted to one end side in the lateral width direction are integrally connected to each other. The shaft support portion 3 supports the hollow transmission shaft 7 projecting into the clutch accommodating portion 4 and the mesh case 1, and the input end 6a protrudes from the cover 8 covering the open end of the clutch accommodating portion 4. Output end
The drive shaft 6 in which 6b is projected outside the mission case 1,
A clutch 9 is provided in the mesh case 1 by penetrating the hollow transmission shaft 7 and connecting and disconnecting the driving shaft 6 and the hollow transmission shaft 7 in the clutch accommodating portion 4. The drive shaft 10, which is biased in the direction opposite to the fork shaft end housing portion 5 when viewed in the widthwise direction, is provided in the mesh case 1 at a level lower than the drive shaft 6, and the drive shaft 10 is provided. The hollow transmission shaft 7 is connected to the hollow transmission shaft 7 by gears 11 and 12, and a transmission shaft 13 is arranged in a lower position than the drive shaft 10 at a substantially central position in the width direction of the transmission case. The output end 13a of the shaft 13 is provided so as to project from the mesh case 1 in the same direction as the output end 6b of the drive shaft 6 described above, and the shift shift metal fitting is provided on the shift shaft 13 between the drive shaft 10 and the shift shaft 13 described above.
A mechanical transmission 14 including 15 is provided, and a fork shaft 16 having one end projecting into the fork shaft end housing 5 is provided in the mesh case 1 at a level higher than the drive shaft 6. The shift lever 17 is arranged and slidably supported so as to be supported by a cover 19 that covers the open end of the fork shaft end receiving portion 5 and is engaged with the fork shaft 16 within the fork shaft end receiving portion 5. Along with the shift fork 18 attached to the fork shaft 16, the shift shift metal fitting on the shift shaft 13 described above.
A mesh device for a traveling work vehicle that is engaged with 15.