JPS5941052B2 - Travel power transmission device for tractors, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a drive shaft that is connected to an engine via a mechanical transmission mechanism and a final traveling drive means (drive wheel or crawler) that is connected via a mechanical transmission mechanism. Multiple sets of speed change gear units are installed between the driven shaft and the driven shaft.
The idling gears in each set of speed change gear units are selectively connected to the shaft on which they are mounted by fitting a hydraulic clutch disposed on the idling gears on the shaft to change the speed of the traveling power. The present invention relates to a transmission device for driving power in a self-propelled vehicle such as a tractor, which is configured to obtain the following.

That is, if an engine stop occurs while a tractor or the like equipped with a hydraulic clutch type transmission device as described above is running, the above-mentioned transmission system, which is supplied with hydraulic oil by an oil pump driven by the engine, Since oil leaks from the hydraulic clutch in the device, the travel power transmission path is cut off at the hydraulic clutch portion, making it impossible to start the engine.

If such a situation occurs when a tractor, etc. is going up or down a slope, or when loading a tractor, etc. onto a truck, etc. along a slope when moving between fields, as is often the case with agricultural tractors, the tractor This is dangerous as it may cause the vehicle to run out of control in the downward direction.

SUMMARY OF THE INVENTION Therefore, the present invention provides a novel method for tractors, etc., which automatically avoids the above-mentioned dangers and also makes it possible to easily start the engine even in the case of an engine stop or malfunction of the engine starting device as described above. The present invention aims to provide a traveling power transmission device.

The configuration of the traveling power transmission device for a tractor or the like according to the present invention will be explained with reference to the illustrated embodiment.As shown in FIG.
The operator sits on a seat 3 on the fuselage, rotates the front wheels 1 using the control handle 4, and steers the tractor, while the rear wheels 2 are rotationally driven by the engine 5 at the front of the fuselage. This invention relates to an example in which the present invention is implemented in a tractor in which 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.

As shown in FIG. 2, the transmission mechanism for the running power of this tractor includes a drive shaft 9 connected to the engine 5 via a mechanical transmission mechanism including a main clutch 8.
A hydraulic clutch type transmission 11 disposed between a driven shaft 10 provided parallel to the drive shaft 9 and an extension portion 9a of the drive shaft 9.
The upper series of idler gears 12a-12f and the driven shaft 10
Idle gears 12a-12f and driven shaft 10 inputted from
A mechanical transmission 16 comprising shift gears 14a to 14c spline-fitted onto the intermediate shaft 13 on an extended line and a dog clutch 15 disposed between the driven shaft 10 and the intermediate shaft 13. It is configured.

The driven shaft 10 described above is connected to the left and right rear wheels 2 or their axles 2a, which are the final traveling drive means, through a mechanical transmission mechanism including the mechanical transmission 16, differential device 50, etc. described above.

As shown in FIGS. 2 and 3, the hydraulic clutch type transmission 11 includes 1. The F1 gear 17 fitted on the drive shaft 9 and the F1 gear 1 loosely fitted on the driven shaft 10 and meshed with this Fl gear 17.
F2 gear unit, 1 consisting of a combination of F2 gear 19 fitted on drive shaft 9 and F2 gear 20 loosely fitted on driven shaft 10 and meshed with this F2 gear 19; A gear unit, an F3 gear 21 fitted on the drive shaft 9, and this F3 gear 2 loosely fitted on the driven shaft 10.
F3 consisting of a combination with F3 gear 22 meshed with F3
The speed change gear unit and the R gear 23 fitted to the drive shaft 9
The R gear meshed with this R gear 23 which is freely rotatably supported.
This R intermediate gear 2 is loosely fitted to the intermediate gear 24 and the driven shaft 10.
The R speed change gear unit is configured to include four sets of R speed change gear units, each consisting of a combination of R gears 25 and R gears 25 that are meshed with each other.

The above Fl, F2°F3 and R loosely fitted to the driven shaft 10
Gears 18, 20, 22 and 25 have Fl, F, respectively.
2. F3 and R hydraulic clutch 26° 27.28 and 29
By selectively operating one of these hydraulic clutches 26 to 29, the idler gear 18 to which the hydraulic clutch 26, 27, 28 or 29 belongs can be operated. 20, 22 or 25 are connected to the driven shaft 10, and the driving shaft 9 and the driven shaft 10 are interlocked and connected at a reduction ratio by a tilting transmission gear unit to obtain a speed change.

Of the above-mentioned hydraulic clutches 26-29, Fl
As shown in FIG. 3, the hydraulic clutch 26, the F2 hydraulic clutch 27, and the R hydraulic clutch 29 are fitted into a clutch housing 30 that is fitted onto the driven shaft 10 in an oil-tight manner. a piston 32 which is slidably biased in the clutch disengagement direction by a spring 31; a pair of friction plates 33 which are slidably supported by the clutch housing 30; and free rotating gears 17, 19 on the driven shaft 10. 2
5 and another set of friction plates 34, which are slidably supported only at the boss portion thereof, and include an oil passage (not shown) formed in the driven shaft 10 and a clutch housing. When pressurized oil is supplied to the oil chamber 36 behind the piston 32 through the oil passage 35 formed in the piston 30, the friction plates 33 and 34 are brought into pressure contact with each other as the piston 32 moves forward, and the clutch is activated. 19 or 25 is configured as a conventional type of hydraulic clutch connected to the driven shaft 10, but only the F3 hydraulic clutch 28 disposed on the F3 transmission gear unit 21 and 22 is constructed according to the present invention. In particular, the hydraulic clutch is configured as follows.

That is, as similarly shown in FIG. 3, this F3 hydraulic clutch 28 includes a clutch housing 30 fitted onto the driven shaft 10, and a piston 32 fitted oil-tightly into the clutch housing 30. and a set of friction plates 33 that are slidably supported by the clutch housing 30.
Unlike other hydraulic clutches, the F3 idler gear 22 on the driven shaft 10 is equipped with another set of friction plates 34, etc., which are slidably supported by the boss portion of the F3 idler gear 22. 26
゜27.29, but this F3 hydraulic clutch 2
The piston 32 at 8 is biased to move in the direction of pressing the friction plates 33 and 34 to operate the clutch by a disc spring 37 disposed within the clutch housing 30.
By applying pressure oil to the oil chamber 39 at the piston 32@ position through an oil passage (not shown) formed in the driven shaft 10 and an oil passage 38 formed in the clutch housing 30, the piston 32 is moved against the disc spring 37. This F3 hydraulic clutch 28 is configured as a spring-load type hydraulic clutch that moves backward and disables the clutch.

Next, the circuit configuration for supplying and discharging hydraulic oil to the hydraulic clutches 26-29 in the illustrated case will be explained with reference to FIG. 42 is a switching valve 4 as shown below.
3, that is, drain the oil from the hydraulic clutches 26, 27, 29 toward the oil tank 40, and also drain the oil from the hydraulic clutch 28.
by applying hydraulic pressure to the fully hydraulic clutch 26-. 29 is deactivated, the F1 hydraulic clutch 26 is activated by applying hydraulic pressure to the neutral position N, and the other hydraulic clutches are deactivated as in the neutral position N. the F1 position, the F2 position where hydraulic pressure is applied to the F2 hydraulic clutch 27 to operate the F2 hydraulic clutch 27, and the other hydraulic clutches are inactivated as in the neutral position N; and the full hydraulic clutch 26. -F3 position where oil is drained from 29 toward the oil tank 40 and only the F3 hydraulic clutch 28 is operated, and the R hydraulic clutch 29
A switching valve 43 is inserted, which has an R position where hydraulic pressure is applied to the R hydraulic clutch 29 to operate the R hydraulic clutch 29, and a neutral position N and an R position where the R hydraulic clutch 29 is inactivated, similar to the neutral position N. A pressure regulating valve 44 is inserted into the circuit 42 to set the hydraulic pressure applied to the hydraulic clutches 26-29.
As shown in the figure, a throttle 45 is inserted in the oil supply circuit leading to the hydraulic clutches 26, 27, and 29.

Note that the mechanical transmission 16 described above has a shift gear 14.
By displacing the a-14c on the intermediate shaft 13, the shift gear 14C and the idler gear 12e mesh to achieve 1st speed (very low speed), and the shift gear 14C and the idler gear 12d engage to achieve the 2nd speed. The meshing of the shift gear 14b and the free rotation gear 12c provides the 3rd speed, the meshing of the shift gear 14a and the free rotation gear 12b provides the 4th speed, and the engagement of the dog clutch 15 provides the 5th speed. It is configured to be selectively obtainable.

In FIG. 2, 51 is a pair of brakes for the left and right rear wheels 2, 52 and 53 are intermediate shafts located on an extension of the drive shaft 9 and interlockingly connected to the drive shaft 9, and 54 is an intermediate shaft 48. P.T.
This is a PTO transmission with one O-axis.

Since the traveling power transmission device according to the present invention is configured as described above, when the engine stops while the tractor is traveling, it operates as follows.

That is, when such an engine stop occurs, the full hydraulic clutch 2 of the hydraulic clutch type transmission 11
Oil leakage occurs from 6-29, but F3 hydraulic clutch 28
When such an engine stop occurs in the operating state, since the F3 hydraulic clutch 28 is configured as a spring-load type, the operating state or engaged state of the F3 hydraulic clutch 28 is maintained. If the transmission path between the rear wheel axle 2a and the engine 5 is not interrupted, and the other Fl, F2 or R oilfield clutch 26.27
Or, if such an engine stop occurs in the operating state of 29, the hydraulic clutch 2 that was in this operating state
Oil leaks from 6°2γ or 29, and the transmission path through the hydraulic clutch is cut off, but due to this engine stop, oil also leaks from the F3 hydraulic clutch 28, causing the F3 hydraulic clutch 28 to be in the engaged state. For this reason, the rear wheel axle 2a is
The transmission path between the engine 5 and the rear wheel axle 2a is connected to the engine 5, and the rear axle 2a is always connected to the engine 5 even when the engine 5 is stopped. This provides the following advantages.

In other words, if the engine unexpectedly stops while driving on an incline and the vehicle automatically moves forward, the rear axle 2
A and the engine 5 are interlocked and connected, so that the engine 5 is driven from the rear axle 2a side, so the engine 5 acts as a brake that suppresses the vehicle's self-propulsion, thereby preventing the vehicle from running out of control. Furthermore, when the once stopped engine 5 is restarted by the drive from the rear wheel axle 2a, the vehicle coasts due to the normal engine braking action, and the vehicle is similarly prevented from running out of control.

Furthermore, when the engine unexpectedly stops, the forward movement of the vehicle pulls the engine 5 and restarts it as described above. In addition, when the engine starting device malfunctions, such as when the battery capacity decreases, the vehicle can be restarted. When the vehicle is moved forward, the engine 5 receives a single drive from the rear wheel axle 2a side, so that it is easily engaged.

Also, the engine 5 after the engine is stopped with the Fl, F2 or R hydraulic clutch 26, 27 or 29 in operation.
At the time of restart, when the hydraulic clutch 26, 27 or 29 that was in the activated state is activated by restarting the engine 5, the spring-load type F3 hydraulic clutch 28 is in the non-activated state due to the restart of the engine 5. Prior to the transition to , the connection between the drive shaft 9 and the driven shaft 10 is briefly made via both the Fl, F2 or R transmission gear unit and the F3 transmission gear unit 21,22. As mentioned above, Fl, F2 and R hydraulic clutches 26
．． Since the throttle 45 is inserted in the oil supply circuit to 27 and 29 to delay the hydraulic action, the engine 5
After restarting, the F3 hydraulic clutch 28 transitions to a non-operating state when the Fl, F2 or R hydraulic clutch 26, 27 or 2
This can be avoided by making the transition to the operating state faster than in step 9.

Note that such so-called double engagement prevention can also be achieved by appropriately setting the relationship between the spring forces of the springs 31 and 37, and in practice,
Such double meshing, if only for a short period of time, does not pose a problem since slip operation may occur due to the clutch engagement power factor.

As is clear from the above description, the traveling power transmission device for a tractor or the like of the present invention provides a mechanical transmission for the drive shaft 9 connected to the engine 5 via a mechanical transmission mechanism and the final traveling drive means 2. A plurality of sets of variable speed gear units are disposed between the driven shaft 10 and the driven shaft 10 connected via a transmission mechanism, and the free rotating gear in each set of variable speed gear units is connected to the shaft 10 on which it is mounted. A traveling power transmission device for a tractor or the like, which is configured to change the speed of the traveling power by selectively engaging the hydraulic clutch disposed on the idler gear on the shaft 10, It is characterized in that only the hydraulic clutch 28 disposed on the idler gear 21 of one of the transmission gear units of the gear units is configured as a spring-load type hydraulic clutch, and the following be effective.

That is, in the hydraulic clutch-type traveling power transmission having the structure described at the beginning, only one hydraulic clutch 28 out of a plurality of hydraulic clutches provided corresponding to a plurality of transmission gear units is replaced by a spring card. As a type of clutch, the spring card type hydraulic clutch maintains conduction of the traveling power transmission path even when the engine is stopped, which prevents the risk of the vehicle running out of control when the engine unexpectedly stops. This has the effect of making it possible to start the engine very easily by triggering it even when the engine is stopped or the engine starting device is malfunctioning.

[Brief explanation of drawings]

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 longitudinal side view of the same embodiment, and Fig. 4 is the same embodiment. FIG. 2... Rear wheel (final traveling drive means), 5...
...Engine, 9...Drive shaft, 10...
- Driven shaft, 11... Hydraulic clutch type transmission,
17...F1 gear, 18...Fl (idling) gear, 19...F2 gear, 20...
・F2 (idling) gear, 21...F3 gear, 22
...F3 (idling) gear, 23, 24...
・R gear, 25...R (idling) gear, 26...
...Fl hydraulic clutch, 27...F2 hydraulic clutch, 28...F3 hydraulic clutch (spring-load type hydraulic clutch), 29...R hydraulic clutch.

Claims (1)

[Claims] 1 A plurality of sets of variable speed gear units are arranged between a drive shaft connected to the engine via a mechanical transmission mechanism and a driven shaft connected to the final travel drive means via a mechanical transmission mechanism. The idling gears in each set of speed change gear units are selectively connected to the shaft on which they are mounted by the operation of a hydraulic clutch disposed on the idling gears on the shaft, and the traveling power is generated. The driving power transmission device for a tractor or the like is configured to change the speed of a tractor, and the hydraulic clutch disposed on the free rotating gear of the tilting speed change gear unit of the speed change gear unit is operated by a spring. A traveling power transmission device comprising a exposed type hydraulic clutch.