JPH0611222Y2 - Mobile agricultural machine transmission - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a transmission that can be applied to a mobile agricultural machine such as an agricultural tractor, and more particularly, to an automatic neutral return mechanism for a transmission that includes a transmission lever when the main clutch petal is depressed. The present invention relates to a speed change device for a mobile agricultural machine that operates.

[Prior art]

For example, referring to FIG. 4, the transmission of the agricultural tractor is provided with a main transmission unit 11 driven from the engine 1 through the main clutch 6, and the main transmission unit 11 is further forward and backward. Wheels 21 are driven at a predetermined speed by an auxiliary transmission unit 17 driven via a forward transmission unit 16. Further, a PTO transmission unit is provided below the main transmission unit 11 in parallel with the main transmission unit 11, and the PTO transmission unit is independent of the traveling system.
It is designed to drive an axis.

When the main transmission unit 11 that is interlocked with the forward / reverse transmission unit 16 and the auxiliary transmission unit 17 is shifted in multiple stages by cutting the main clutch, the other transmission units 16 and 17 are interlocked and the respective transmission gears are meshed. If the gear shift lever of the main transmission unit 11 is operated while the gear shifts, the resistance of meshing of the gear shift gears is large, and the operating force of the gear shift lever becomes very heavy.

[Problems to be solved by the invention]

By the way, in order to solve the above-mentioned problem, the main clutch equipped on the aircraft is operated in the half-clutch state and the shift lever is operated, or the other forward / reverse shift unit 16 or the auxiliary shift unit 17 is temporarily returned to the neutral state. Therefore, it is necessary to operate the shift lever after reducing the meshing resistance of each shift gear, but the operation is very troublesome.

Therefore, the present invention has been made in view of the above-mentioned conventional circumstances to solve the problem, and only the shift fork is moved to the neutral position N by depressing the clutch pedal beyond the disengaged state of the main clutch, An object of the present invention is to provide a transmission device for a mobile agricultural machine that does not require an operation of moving the shift lever (forward / backward operating lever) again to the shift position by keeping the shift lever at the shift position. .

[Means for solving problems]

Means for Solving the Problems The present invention to achieve the above object is to provide a transmission device for a mobile agricultural machine having a plurality of speed change parts that are disengaged by a main clutch, including a speed change lever including a speed change lever mounted in one of the plurality of speed change parts. The automatic neutral return mechanism of the device is provided with a switch arranged at a reverse position of the speed change lever, a switch arranged at a forward position of the speed change lever, and a shift fork engaging with a switching desk of the speed change unit at a forward position.
A pair of solenoids that switch between neutral position and reverse position,
A safety switch arranged in the vicinity of the clutch pedal that connects and disconnects the main clutch, and the shift fork to be returned from the forward position or the reverse position to the neutral position by stepping on the clutch pedal beyond the disengaged state of the main clutch. The control circuit energizes the solenoid while reenergizing the solenoid to return the shift fork to the position corresponding to the shift lever when the clutch pedal is released from the safety switch.

[Action]

Therefore, when the clutch pedal is depressed beyond the disengaged state of the main clutch, the solenoid is excited to move the shift fork from the forward or reverse position to the neutral position, while the solenoid is re-energized when the clutch pedal is released from the safety switch. Then, the shift fork automatically moves to a position corresponding to the shift lever.

〔Example〕

As shown in FIG. 5, the transmission M of the agricultural tractor includes a clutch housing 2 having a front portion fixedly mounted on the rear portion of the engine 1, and a front portion fixedly mounted on the rear portion of the clutch housing 2 and extending rearward. The front transmission case 3 and a rear transmission case 4 which is fixedly attached to the rear portion of the front transmission case 3 and extends rearward are integrally coupled to each other. The transmission transmission M is an agricultural tractor. It is also used for the monocoque machine body 5.

A main clutch 6 for connecting and disconnecting the power of the engine 1 is installed in the clutch housing 2, and the main clutch 6 is connected to a main clutch petal 10 equipped on the aircraft through a connecting rod 7 shown in FIG. Linked together,
At the (A) position where the petal 10 is not stepped on, it is in the "in position" where it is connected to the engine 1, but when the petal 10 is stepped at the (A) position, it is in the "disconnected position" where it is not connected to the engine 1.

The transmission of the agricultural tractor is constructed as shown in FIG. That is, the main transmission portion 11 is disposed behind the rear mesh case 4, and the main gear portion 11 extends from the rear mesh case 4 through the front mesh case 3 into the clutch housing 2. Transmission shaft 12 linked to shaft 13
A gear shift lever is provided which is driven by and can shift gears in multiple stages.

Further, the main transmission portion 11 is interlocked with a forward-reverse transmission portion 16 arranged at the front portion of the rear mesh case 4 via a transmission shaft 14 extending forward and a sub clutch 15.

The forward / reverse transmission unit 16 is provided with a sub-transmission unit 17 disposed below it.
As shown in FIG. 6, the axle drive shaft 19 of the sub-transmission unit 17 drives the axle 20 to which the rear wheel 21 is attached via the differential mechanism 22 as shown in FIG. However, the forward / reverse shift unit 16 has a shift lever described later.
40 is provided, and the sub-transmission unit 17 is also provided with a gear shift lever (not shown).

Further, as shown in detail in FIG.
Is provided with a transmission shaft 14a that is driven from the transmission shaft 14 via a sub clutch 15, and the transmission shaft 14a is provided with a switching desk 23 that is only slidable and front and rear positions sandwiching the switching desk 23. A transmission gear 24 and a transmission gear 25 which are freely rotatable are provided. This switching desk 23 rotates the rear wheel 21 in the forward direction when it is switched to the forward F position where it meshes with the transmission gear 24, and when it switches to the reverse B position where it meshes with the transmission gear 25, the rear wheel.
21 is configured to be freely switchable between forward and backward so as to rotate in the reverse direction, and both transmission gears 2 are provided between the forward F position and the reverse B position.
The neutral N position that does not mesh with 4,25 is set.

Further, reference numeral 26 shown in FIG. 6 is a front wheel drive shaft which is driven via the auxiliary transmission unit 17.

As shown in FIG. 1A, the forward / reverse shift unit 16 is provided with an automatic neutral return mechanism 28 of the transmission including a shift lever 40. The automatic neutral return mechanism 28 is configured as follows. ing. In other words, the forks connected to the switching desk 23
27 is forward F / neutral N along the axis of shift rail 29
・ This fork is positioned over each position of reverse B
27 is connected to a switching arm 31 fixed to a fulcrum shaft 30 rotatably supported on the case 4 in a direction orthogonal to the shift rail 29.

Outside the case 4 of the fulcrum shaft 30, there are a single interlocking arm 32 that rotates integrally with the fulcrum shaft 30 and a restoring arm 34 that is rotatably pivoted around the fulcrum shaft 30 and that forms a pair. Each of the restoring arms 34 is fixedly provided with a restoring pin 33 capable of contacting the side edge of the interlocking arm 32. Further, a mounting plate 35 having locking portions 35a on both left and right sides is attached to the case 4, and each restoration arm 34 has its restoration pin 33.
And a locking portion 35a of the mounting plate 35 are connected to each other by a spring 36, and the springs 36 are urged in directions away from each other.

Two connecting links 37, whose proximal ends are pivotally connected to the tips of both of the restoring arms 34, have their tips pivotally connected to the inner wire 39a of the single Bowden wire 39.

In addition, the fulcrum shaft 38 fixed to the mounting plate 35 is attached to the gearshift lever 40.
A fixed boss 40a is rotatably positioned at the base end of the connecting arm 41 fixed to the boss 40a and having a phase different from the extension direction of the speed change lever 40, and the above-mentioned interlocking arm.
The tip end of 32 is pivotally connected to both sides of the connecting link 43, so that the speed change lever 40 and the switching desk 23 in the case 4 are configured to integrally move together.

The automatic neutral return mechanism 28 configured as described above operates in conjunction with the depression of the incremental petal 10 described above. That is, as shown in FIG. 2, the other end of the inner wire 39a is pivotally connected to the tip end of a swing arm 46 which is rotatably provided around a fulcrum shaft 45 fixed to the machine body. The boss fixed to the base end of the main clutch petal 10 described above.
47 is rotatably supported by a fulcrum shaft 49 fixed to the machine body. The tip of the interlocking 50 whose base end is fixed to this boss 47 is
The operation 51 is extended below the operation 51 that rotates integrally with the swing arm 46, and the operation 51 is moved upward by interlocking with the depression of the petal 10 to a position (C) beyond the "disengaged position" of the main clutch. It is provided in the position.

As shown in FIG. 1B, when the shift lever 40 is operated to the forward F position in the arrow direction, the interlocking arm 32 moves downward and the fork 27 moves in the arrow direction in conjunction with this.
When the switching desk 23 meshes with the transmission gear 24, the forward / rearward speed change unit 16 switches in the forward direction.
Since 50 and the operation 51 are at the positions shown in FIG. 3 (A) and the inner wire 39a is loose, the restoring pin 33 that contacts the lower edge of the interlocking arm 32 moved to the forward F position is also downward. As a result, the two connecting links 37 and the restoring arm 34 are both held in an open leg posture with wide intervals.

When the petal 10 is stepped on to the position (a) in FIG. 2 in this state, the main clutch 6 becomes the “disengaged position”, and the main transmission unit 11
However, at this stepped-in position, the interlocking member 50 moved in the direction of the arrow swings to the position where it comes into contact with the operation 51. When the petal 10 is further stepped to the (C) position, the interlocking 50 pushes the operation 51 upward, and in conjunction with this, the swinging arm 46 pivoted in the direction of the arrow pulls the inner wire 39a. Connecting link 37 and restoring arm 34
Shifts to the open leg posture with a narrow interval against the biasing force of the spring 36, as shown in FIG. 1C.

In conjunction with this, as the restoring pin 33 pushes the interlocking arm 32 back to the neutral N position, the fulcrum shaft 30 rotates, and the fork 27 connected to the switching desk 23 is moved in the arrow direction to restore it to the neutral N position. At the same time, the shift lever 40 is moved in the direction of the arrow to restore the neutral N position.

When the petal 10 is returned to the (a) position at this restoration position, the interlocking movement 50 and the operation 51 are associated with the ascent of the petal 10 and are shown in FIG. 3 (A).
Since the inner wire 39a is loosened by the urging force of the spring 36, the two connecting links 37 and the restoring arm 34 return to the open leg position with the wide interval shown in FIG. It is possible to perform the next forward F position or reverse B position.

Although not shown in particular, the shift lever 40 operated to the reverse B position can be automatically returned to the neutral N position by depressing the petal 10 to the (C) position as described above.

It is most effective to provide the automatic neutral return mechanism 28 in the forward / reverse shift section 16 disposed between the main shift section 11 and the sub shift section 17, but the main shift section 11 or the sub shift section is most effective. It may be provided at 17.

The above is the automatic neutral return mechanism 28 operated by mechanical means.
However, the automatic neutral return mechanism 68 operated by electric means shown as the second embodiment will be described below while avoiding duplication with the previous example.

Second Embodiment The automatic neutral return mechanism 68 in this example is constructed as shown in FIGS. In this example, when the automatic neutral return mechanism operates, even if the shift fork 27 returns to the neutral N position, the shift lever 40 remains in the shift position without returning to the neutral N position.

Therefore, by providing the shift lever 40 in the forward / reverse shift unit 16, the shift lever 40 remains only the shift fork 27 in conjunction with the depression of the petal 10 without performing a shift operation each time. Since it can be moved to the gear shift position,
Only the operation of the main speed change lever for operating 11 is required, and the operation is extremely simple, and the speed change lever 40 does not move, which is advantageous in that it is safe, and is configured as follows.

That is, in FIGS. 7 to 8, the interlocking arm 32 is fixed to the boss 30a rotatably positioned on the fulcrum shaft 30 at a predetermined angle. The speed change lever 40 is rotatably positioned on another fulcrum shaft 80 via the boss 40a, and the forward F position,
Further, at the reverse B position, switches 60 and 61 are provided which are turned on by contact with the speed change lever 40 operated to that position and turned off by the escape of the speed change lever from that position.

Further, the other ends of the two operation rods 62 and 63 whose base ends are coaxially pivotally attached to the interlocking arm 32 are different in phase from each other by approximately 90 degrees with respect to the shift rail 29 in the parallel direction and the orthogonal direction. The solenoids 64, 65 provided are movably connected to each other, and both solenoids 64, 65 are provided so as to swing in conjunction with the swing of the interlocking arm 32 about the respective fulcrums 66, 67, Each of the operation rods 62, 63 moves or retracts by energizing the solenoid as shown by an arrow in FIG. 10 described later.

Further, as shown in FIG. 9, the operation plate 69 is fixedly mounted on the petal 10, and the safety switch 70 disposed at the stepped-in position (c) of the petal 10 is normally in the OFF state, but the petal 10
The operating plate 69 when the
When is touched, it is switched to the ON state.

The safety switch 70 and the switches 60 and 61 are the first
As shown in Fig. 0, both solenoids 64, via the control circuit 81,
It is connected to 65.

Therefore, in the forward F switching state, when the petal 10 is stepped on to the (C) position, the aircraft is stopped and the safety switch 70 is turned from OFF to ON and the solenoid 64 is turned ON.
Is energized. Along with this, the movement of the solenoid 64 is excited to pull the operating rod 62, so that the shift fork 27 moves from the forward F position to the neutral N position while the shift lever 40 remains in the forward F position. . Then, after shifting the main transmission unit 11 or the sub-transmission unit 17,
When the petal 10 is gradually released to start, the safety switch 70 is turned from ON to OFF (the main clutch 6 is not yet cut), but the following operation is performed until the main clutch 6 is connected.

That is, when the safety switch 70 is switched from ON to OFF, the shift lever 40 is still in the forward F position, so the control circuit 81 determines that the switch 61 is in the ON state, and the solenoid 64 is excited to move. The rod 62 is now projected to move the shift fork 27 from the neutral N position to the forward F position.

If the transmission lever 40 is set to the neutral N position while the petal 10 is stepped on, the petal 10 is released and the safety switch 70 is released.
The shift fork 27 is not activated even if is switched from ON to OFF.

Also, while stepping on the petal 10, move the speed change lever 40 forward
From the position to the reverse B position, the safety switch 70
Is switched from ON to OFF, but the control circuit 81 determines that the switch 60 is in the ON state, excites the movement of the solenoid 65, and causes the operation rod 63 to project to shift the shift fork.
27 is moved from the neutral N position to the reverse B position.

In this example, even if the shift fork 27 is returned to the neutral N position by the automatic neutral return mechanism 68, the shift lever 40
Can remain in its shift position. When the foot is released from the petal 10, the safety switch 70 is switched to OFF, but the control circuit 81 judges the ON state of the one switch 60 (or 61) which is in contact with the shift lever 40 remaining in the shift position and is connected to this switch. The shift fork 27 can be moved to the shift position left by the shift lever 40 by re-exciting the solenoid.

The safety switch 70 has a petal when the engine is started.
It is a safety switch that the engine will not start unless you depress 10 to the (c) position to turn it on.

Third Embodiment Next, as shown in the block diagram of FIG. 11, the sub clutch 15 interposed between the main transmission unit 11 and the forward / reverse transmission unit 16 is used as in the previous example by depressing the petal 10. A third embodiment will be described in which the "off state" is set.

The movable clutch 15a, which constitutes one of the sub-clutch 15 shown in FIG. 5, does not mesh with the "on" state in which its claw meshes with the stationary clutch by the movement of a fork (not shown) connected to this movable clutch 15a. It is switched to "disconnected state".

The inner wire 75a of the Bowden wire 75, one end of which is connected to an arm (not shown) for moving the fork, is an interlocking arm fixed to the boss 47 of the main clutch petal 10.
It is pivotally connected to the tip of 76. And the sub clutch
Reference numeral 15 is set so that the petal 10 is brought into the "disconnected state" by stepping on the petal 10 to a position (c) beyond the position (a) where the main clutch 6 is disconnected.

Therefore, at the (A) position of the petal 10 shown in FIG. 12,
Both the sub clutch 15 and the main clutch 6 are in the "on" state, and the power of the engine 1 is transmitted to the forward / reverse shift unit 16 via the main shift unit 11 and the axle 21 is driven.

Then, when the petal 10 is stepped over the (a) position where the main clutch 6 is in the disconnected state to the (d) position, the sub clutch 15 can be brought into the "disconnected state" in conjunction with this.

In this way, the main transmission unit 11 and the forward / reverse transmission unit 16 to the auxiliary transmission unit
By disconnecting from the power transmission path to the wheels 21 via 17, the speed change lever only has to change the speed of the single main speed change section 11. The switching operation of the part 11 is performed by moving the forward / reverse speed changing part 16 in the other disconnected state.
There is an advantage that it is possible to reduce the mesh resistance of each transmission gear from the wheel to the wheel 21.

In addition, the sub clutch 15 is a dock clutch, and if the main clutch 6 is connected after the sub clutch 15 is connected first, the power transmission is smoothly connected.

[Effect of device]

As described above, the present invention relates to a transmission device for a mobile agricultural machine having a plurality of transmission parts that are disengaged by a main clutch, and includes a transmission lever including a transmission lever mounted in one of the plurality of transmission parts. The automatic neutral return mechanism switches the switch located at the reverse position of the shift lever, the switch located at the forward position of the shift lever, and the shift fork that engages with the switching desk of the shifting unit to the forward position, the neutral position, and the reverse position. A pair of solenoids, a safety switch arranged in the vicinity of a pedal that engages and disengages the main clutch, and depression of the pedal beyond the disengaged state of the main clutch to return the shift fork from the forward position or the reverse position to the neutral position. The position where the shift fork corresponds to the shift lever when the solenoid is excited and the pedal is released from the safety switch. Since it consists of a control circuit that re-energizes the solenoid to restore it, by depressing the clutch pedal beyond the disengaged state of the main clutch, only the shift fork is moved to the neutral position, while the shift lever is kept in the shift position. It is not necessary to operate the shift lever (forward / backward operation lever) again to the shift position (main and sub shift lever operations only).

Further, since the forward / reverse operation lever itself does not move suddenly to the neutral position N in the shift position, even if the driver carelessly exposes a part of the body to the operating range of the lever, It is possible to prevent a situation where the lever is abruptly hit, and it is possible to perform the work safely without causing a danger to the driver.

Furthermore, by re-depressing the clutch pedal required for the main and auxiliary shift operations, it is possible to move only the shift fork to the original position of the forward / backward operation lever, which greatly improves the operability. .

Therefore, in order to solve the problem that the meshing resistance of each shift gear is large and the operating force of the shift lever becomes very heavy as in the past, shifting the main clutch equipped on the aircraft to the half clutch state It is possible to solve the problem that it is necessary to operate the shift lever after reducing the meshing resistance of each shift gear by operating the lever or once returning the other main transmission unit or the sub transmission unit to the neutral state. .

[Brief description of drawings]

1 to 6 show the first embodiment, FIG. 1A is a side view of the automatic neutral return mechanism in the neutral position, and FIG. 1B is an operation explanatory view of the automatic neutral return mechanism showing the forward movement position. FIG. 1C is an operation explanatory view showing the return position of the automatic neutral return mechanism, FIG. 2 is a side view showing the stepped-on state of the petal, and FIG.
(D) is an explanatory view of the action when the petal is stepped on, FIG. 4 is a block diagram, FIG. 5 is a vertical cross-sectional side view of the shift transmission, and FIG. 6 is a gear train diagram of essential parts. 7 to 10 show a second embodiment, FIG. 7 is a side view of a main part, FIG. 8 is a side view of a speed change lever, and FIG. 9 is a side view showing a stepped state of a petal. The figure is a block diagram showing the control circuit. 11 to 12 show the third embodiment, FIG. 11 is a block diagram, and FIG. 12 is a side view showing a stepped state of the petal. 6 …… Main clutch, 7 …… Coupling rod, 10 …… Main clutch petal, 11 …… Main shift unit, 16 …… Forward / reverse shift unit, 17 …… Sub shift unit, 21 …… Wheels, 23 …… Switching desk,
24 …… gearshift, 25 …… gearshift, 27 …… fork, 28
...... Automatic neutral return mechanism, 30 ...... fulcrum shaft, 31 ...... switch arm, 32 ...... interlocking arm, 33 ...... restoration pin, 34 ...... restoration arm, 37 ...... connection link, 39 ...... Boden wire, 40 …
… Gear change lever, 46 …… Swing arm, 50 …… Interlocking, 51…
… Activated.

Claims (1)

[Scope of utility model registration request] 1. A transmission device for a mobile agricultural machine having a plurality of speed change parts that are connected and disconnected by a main clutch, wherein one of the plurality of speed change parts (11, 16, 17) is equipped with the speed change part (16). Automatic neutral return mechanism of the transmission including the transmission lever (40)
(68) a switch (60) arranged at the reverse position (B) of the speed change lever (40), a switch (61) arranged at the forward position (F) of the speed change lever (40), and the speed change unit. Switching desk for (16) (23)
The pair of solenoids (64, 64) that switch the shift fork (27) that engages with the forward position (F), neutral position (N), and reverse position (B).
65), a safety switch (70) arranged in the vicinity of the clutch pedal (10) for connecting and disconnecting the main clutch (6), and a crunch pedal (1) that exceeds the disengaged state of the main clutch (6).
The shift fork (27) is moved to the forward position by depressing (0).
(F) or the reverse position (B) to return to the neutral position (N) to energize the solenoid (64) or (65) while releasing the clutch pedal (10) from the safety switch (70) Sometimes, the solenoid (64) or the solenoid (64) is returned to return the shift fork (27) to a position corresponding to the shift lever (40).
A transmission device for a mobile agricultural machine comprising a control circuit (81) for re-exciting (65).