JPS5941053B2 - Traveling power transmission device for tractors, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traveling power transmission device for a self-propelled vehicle such as a tractor, and the present invention relates to a traveling power transmission device for a self-propelled vehicle such as a tractor. This is what we provide.

In self-propelled vehicles such as tractors, tractors are equipped with a hydraulic clutch-type transmission or a planetary gear-type transmission that changes gears using a clutch operated by hydraulic pressure or a clutch and brake in the traveling power transmission device. When an engine stop occurs, in which the engine stops unexpectedly, the drive of the hydraulic pump for supplying hydraulic pressure is stopped, so hydraulic pressure is not applied to the clutch or brake described above, and the clutch section or The transmission path of driving power is cut off at the clutch and brake section, making it impossible to start the engine.

If this situation occurs when the tractor is moving all the way downhill, or when the tractor is being loaded onto a truck along a slope when moving between fields, as is often the case with agricultural tractors, the tractor may This is dangerous as it may cause the vehicle to run out of control in the downward direction.

The object of the present invention is to automatically avoid the above-mentioned dangers, and also to easily start the engine even in the case of an engine stop or malfunction of the engine starting device as described above, such as a tractor, etc. The object of the present invention is to provide a novel driving power transmission device in a vehicle.

Regarding the illustrated embodiment, to explain the configuration of the traveling power transmission device for a tractor or the like according to the present invention, as shown in FIG. An operator sits on the tractor 3 and rotates the front wheels 1 using the steering bundle 4 to steer the tractor.
The rear wheels 2 are rotationally driven by an engine 5 at the front of the machine body to cause the tractor to run, and a working machine connected to the tractor is raised and lowered by a hydraulic lift mechanism 6 and is driven by a PTO shaft 7. This invention relates to an example in which the present invention is implemented in a tractor manufactured by

As shown in FIG. 2, the driving power transmission mechanism of the tractor includes a drive shaft 9 that is interlocked with the engine 5 via a main clutch 8, and a driven shaft 10 that is provided parallel to the drive shaft 9. a hydraulic clutch type transmission 11 disposed between the two, and a series of idler gears 1 on the extension 9a of the drive shaft 9.
Idle gears 12a-12f that are input from the driven shaft 10 and an intermediate shaft 13 on the extension line of the driven shaft 10
The mechanical transmission 16 includes shift gears 14a-14c spline-fitted thereto and a dog clutch 15 disposed between the driven shaft 10 and the intermediate shaft 13. Furthermore, the following frictional engagement part 3
9 is provided.

That is, as clearly shown in FIG. 3, a gear 37 is fitted onto the drive shaft 9, and a gear 38 meshed with the gear 37 is loosely fitted onto the driven shaft 10. The above-mentioned frictional engagement portion 39 is disposed on this latter gear 38.

The frictional engagement portion 39 includes a cylindrical housing 40 that is fitted onto the driven shaft 10, a piston 41 that is slidably fitted in the housing 40 in an oil-tight manner, and
The configuration includes one set of friction plates 42 that are slidably supported by the housing 40, and another set of friction plates 43 that are slidably supported by the gear 38 at the boss portion thereof. has been done.

The piston 41 in the friction engagement portion 39 is moved between the friction plates 41 by a disc spring 44 disposed inside the housing 40.
2.43 is moved and energized in the direction of pressing the piston 41, and pressurized oil is supplied to the oil chamber 46 in front of the piston 41 through an oil passage (not shown) formed in the driven shaft 10 and an oil passage 45 formed in the housing 40. The piston 41 is moved back by supplying the friction plates 42 and 43, thereby releasing the pressure contact between the friction plates 42 and 43.

Therefore, when the hydraulic action on the piston 41 is released, the friction retaining portion 39 moves the friction plates 42 and 43 by the force of the disc spring 44.
The frictional engagement between the drive shaft 9 and the driven shaft 10, and hence the connection between the engine 5 and the rear wheel 2 which is the final driving means, is achieved through pressure contact. 39, as shown in FIG.
The hydraulic pressure set by the pressure regulating valve 48 is always applied by the hydraulic pump 47 driven by the hydraulic pump 47 .

Therefore, when the engine 5 is stopped and the drive of the hydraulic pump 47 is stopped and the hydraulic action on the frictional engagement part 39 or its piston 41 is released, the frictional engagement part 39 is automatically engaged by the force of the disc spring 44. The engine 5 and the rear wheels 2 are automatically connected.

As shown in FIG. 2-3, the hydraulic clutch type transmission 11 has an F gear 17 fitted on the drive shaft 9 and an F gear 17 loosely fitted on the driven shaft 10 and meshed with the F gear 11.
l An F1 gear shift gear unit consisting of a combination with a gear 18, an F2 gear 19 fitted on the drive shaft 9, and an F2 gear 20 loosely fitted on the driven shaft 10 and meshed with the F2 gear 19.
and the F3 gear 22 meshed with the F3 gear 21 loosely fitted on the driven shaft 10 of the F3 gear 21 fitted on the first drive shaft 9. The F3 speed change gear unit consists of the
3 and an R intermediate gear 24 meshed with the R intermediate gear 24 and an R gear 25 loosely fitted onto the driven shaft 10 and meshed with the R intermediate gear 24. It is composed of

The above-mentioned Fl, F2. F3 and R
Tooth molds 18, 20° 22 and 25 have Fl, F, respectively.
2. F3 and R hydraulic clutches 26, 27, 28 and 29
By selectively engaging any one of these hydraulic clutches 26 to 29, the idler gears 18, 20 of any one to which the hydraulic clutch 26, 27, 28 or 29 belongs , 22 or 25 are connected to the driven shaft 10, and the driving shaft 9 and the driven shaft 10 are interlocked and connected by a reduction ratio by one of the speed change gear units to obtain a speed change.

As shown in FIG. 3, each of the above-mentioned hydraulic clutches 26 to 29 includes a clutch housing 30 fitted onto the driven shaft 10, and a clutch housing 30 that is oil-tightly fitted into the clutch housing 30 and is clutched by a spring 31. A piston 32 that is biased to slide in the detachment direction, a set of friction plates 33 that are slidably supported by the clutch housing 30, and a piston that slides on the free rotating gear on the driven shaft 10 at its hub portion. The clutch housing 30 is configured as a multi-plate type equipped with another set of friction plates 34, etc., which are freely supported. When pressurized oil is supplied to the oil chamber 36 behind the piston 32 through the piston 35, the friction plates 33 and 34 are brought into pressure contact with each other as the piston 32 moves forward, and the clutch is engaged.
is connected to the driven shaft 10.

In addition, as shown in FIG. 2, the mechanical transmission 16 described above is operated to shift gears 13a to 14C on the intermediate shaft 13 so that the shift gears 14c and idling gears 12e mesh with each other to reach the first speed (super speed). low speed), shift gear 14c and idler gear 1
When the shift gear 14b and the idler gear 12c engage with each other, the 2nd speed is established; when the shift gear 14b and the idler gear 12c engage with each other, the 4th speed is established; and when the dog clutch 15 is engaged It is configured so that five speeds can be selectively obtained.

In FIG. 2, 50 is a differential device for left and right rear wheels 2;
A pair of brakes for the left and right rear wheels 2, 52 and 53 an intermediate shaft located on an extension of the first drive shaft 9 and interlockingly connected to the drive shaft 9, and 54 a pair of brakes disposed between the intermediate shaft 48 and the PTO shaft 7; PT
It is an O transmission.

The traveling power transmission device according to the present invention includes the main clutch 8
The drive shaft 9 is connected to the engine 5 through a mechanical transmission mechanism including a drive shaft 9, and the drive shaft 9 is connected to the rear wheel 2 through another mechanical transmission mechanism including the mechanical transmission 16 and differential 50. Since the above-mentioned frictional engagement portion 39 is provided between the driven shaft 10 and the driven shaft 10, when the engine stops while the tractor is running, the following effects occur. It is something.

That is, when such an engine stop occurs, the hydraulic clutch 26 of the hydraulic clutch type transmission 11
-29, and all the clutches 26-29 are inactive, so the interlocking connection between the first drive shaft 9 and the driven shaft 10 via the transmission 11 is cut off, and this hydraulic clutch type The interlocking connection between the engine 5 and the rear axle 2a via the transmission 11 is broken, but if the engine stops as described above, the hydraulic pump 41 is simultaneously stopped and the frictional engagement portion 39 is disconnected. Since oil leakage also occurs, the engaging portion 39 is frictionally engaged by the action of the spring 44, and the gear 38 is coupled to the driven shaft 10, so that the gears 37 and 38 are connected between the drive shaft 9 and the driven shaft 10. The rear axle 2a is connected to the engine 5 in a connected relationship.

Therefore, when an unexpected engine stop occurs while traveling on an incline and the vehicle automatically moves forward, the rear axle 2a and the engine 5 are interlocked and the engine 5 is driven from the rear axle 2a side. Therefore, the engine 5 acts as a brake to suppress the vehicle's self-propulsion, preventing the vehicle from running out of control, and the engine 5 once stopped.
When the engine is restarted by the drive from the rear axle 2a described above, the vehicle coasts due to the normal engine braking action, and the vehicle is similarly prevented from running out of control.

Furthermore, in the event of an unexpected engine stop, the engine 5 is engaged and restarted by the vehicle's self-propulsion as described above.In addition, when the battery capacity decreases or the engine starting device malfunctions, when the vehicle is moved forward, the engine 5 is restarted. 5 receives 1 drive from the rear wheel axle 2a side, so that it can be easily hooked.

Note that when the engine 5 is restarted after the engine is stopped, any hydraulic clutch 26-2 of the hydraulic clutch type transmission 11 that was in an operating state before the engine stopped
When 9 is activated by restarting the engine 5, the distance between the drive shaft 9 and the driven shaft 10 is short for a short time, prior to the time when the friction retaining portion 39 shifts to the disengaged state due to the restart of the engine 5. However, it is the spring 3 that prevents the transmission gear unit in the hydraulic clutch type transmission 11 from being connected via both the detour gears 37 and 38.
1 and 44, or the hydraulic clutch 26-2 of the hydraulic clutch type transmission 11.
This can be done by means such as inserting a throttle into the oil supply circuit to 9, and in practice, the short-term double connection of 7 drive shaft 9 and driven shaft 10 as described above is Also, slip operation occurs in one clutch and does not cause any particular trouble.

As is clear from the above description, the traveling power transmission device for a tractor or the like of the present invention has a frictional engagement portion 39 that is brought into frictional engagement by the force of the spring 44 when the hydraulic action is released. When frictionally engages, the transmission shaft 9 connected to the engine 5 by a mechanical transmission mechanism and the other transmission shaft 10 connected to the final traveling drive means 2 by a mechanical transmission mechanism are connected to the frictional engagement part. 39, so that when the engine 5 is stopped, the hydraulic action on the frictional engagement portion 39 is released to automatically establish the connection between the engine 5 and the final travel drive means 2. Even in a propulsion power transmission system in which gears are changed by a clutch operated by hydraulic pressure or a clutch and brake, the engine and final propulsion drive means are always connected when the engine is stopped. This prevents the risk of the vehicle running out of control when the engine unexpectedly stops, and also makes it possible to start the engine very easily by triggering it even if the engine starting device malfunctions when the engine stops unexpectedly. .

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a tractor equipped with an embodiment of the present invention, Fig. 2 is a power transmission system diagram of the same tractor, Fig. 3 is a vertical sectional side view of the main parts of the same embodiment, and Fig. 4 is the same. It is a hydraulic circuit diagram in an example. 2... Rear wheel (final traveling drive means), 5...
...Engine, 9...Drive shaft, 10...
- Driven shaft, 37...Gear, 38...Gear, 39...Frictional engagement part, 40...Housing, 41... Piston, 42, 43...
...Friction plate, 44... Disc spring (spring), 47... Hydraulic pump.

Claims (1)

[Claims] 1. When the hydraulic action is released, the frictional engagement part is brought into frictional engagement by a spring force, and when this frictional engagement part engages in frictional engagement, the final traveling drive is connected to the transmission shaft connected to the engine by a mechanical transmission mechanism. Another transmission shaft connected to the means by a mechanical transmission mechanism is provided so as to be connected by the friction engagement part, and when the engine is stopped, the hydraulic action on the friction engagement part is released to connect the engine. A traveling power transmission device for a tractor, etc., configured to obtain automatic connection between final traveling drive means.