JPH0547701Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a front wheel speed increasing device for an agricultural tractor that increases the speed of the front wheels when the machine is turning.

(b) Prior art In a front wheel speed increasing device for an agricultural tractor,
There are already models in which a differential gear for speeding up the front wheels is installed in the front wheel transmission system, and a disc brake is attached to the differential shaft of this differential gear that does not transmit power to the front wheels, so that the front wheels can be braked when speeding up. Proposed.

(c) Problems to be solved by the invention The disc brake according to the invention has a number of mating plates attached to the case, and the disc plate interposed between the mating plates is locked to the outer periphery of the spline boss. Furthermore, since the spline boss must be spline-fitted to the differential shaft, assembly is troublesome.

(d) Means for solving the problem The present invention includes a differential device that increases the speed of the front wheels in the front wheel transmission system, and a differential shaft that does not output power to the front wheels of the differential device is installed in the transmission case. The support is used as a cylinder of the desk brake, and the return spring of the piston fitted thereon is supported on the outer periphery of the sleeve, and a spline boss holding the desk plate on the outer periphery is fitted on the outside of this sleeve. By spline-fitting the differential shaft to the spline boss, the disc brake assembly and the differential shaft of the differential gear can be easily assembled, thereby solving the above-mentioned problems.

(E) Function During work, when the manual operating tool is set to the front wheel speed increasing position and the front wheel turning angle becomes larger than a specified value, the wet disc brake is activated and the differential shaft of the differential device in the front wheel drive system is stopped. The front wheels accelerate and the aircraft turns rapidly.

When assembling the disc brake and differential, a piston is inserted into the support that becomes the cylinder, a spacer with a return spring attached to the outer periphery is inserted into the shaft hole of the support, and a large number of disc plates are attached to the spline boss. At the same time as mounting, a large number of mating plates are interposed between each disk plate and fit into the grooves of the support, and the outside thereof is fixed with a retaining ring that fits into the circumferential groove on the outer side of the inner periphery of the support. The support is constructed in one piece, and the assembled support is inserted into a hole drilled in the partition wall of the mission case and screwed with a bolt.

Next, a non-transmitting differential shaft is inserted into the front wheels of the differential gear from the other side, and its end portion is spline-fitted to the spline boss.

(F) Example An example of the present invention will be explained with reference to the drawings.
In the traveling transmission mechanism of an agricultural tractor, 1 is a main transmission section, 2 is a front and rear transmission section, 3 and 4 are auxiliary transmission sections, and a differential pinion shaft 6 transmits power to a rear axle 5.
The front wheel power take-off gear 7 is spline-fitted and fixed, and the counter gear 10 loosely fitted to the reduction shaft 8 of the auxiliary transmission section 4 via a needle bearing 9 is meshed with the passive gear 12 of the differential gear 11. Passive gear 1
2 is screwed onto the differential case 15 with bolts 16, and the cylindrical portion 33 extending toward the front and rear of the differential case 15 is attached to the front portion of the rear transmission 27 via bearings 13 and 14; It is supported by a support 32 attached to the rear bulkhead 30 with a bolt 31, and a pin 22 is attached to the differential case 15.
A pinion 18 and a washer 19 are attached to both ends of the shaft 17 fixed at the
18, side gears 20 and 23 having washers 21 interposed on their outer end surfaces are engaged from the front and rear, a front wheel drive shaft 24 is spline-fitted to the front side gear 20, and a differential shaft 25 is fitted to the rear side gear 23. It is spline fitted and fixed in position by a retaining ring 26.

Several holes 35 into which the balls 34 are inserted are bored in the cylindrical portion 33, and the sleeve 36 is in the state shown in FIG.
When the sleeve 36 is moved forward from this state, the balls 34 are press-fitted into the conical holes 37 provided on the outer periphery of the differential shaft 25, and the cylindrical portion 33 and the differential shaft 25 are and rotate as one.

A piston 40 having a rotation prevention protrusion 41 on the rear end of the outer periphery has a seal ring 3 in the support 32.
The projections 41 are fitted loosely into the grooves 42 of the support 32 to prevent rotation, and are press-fitted into the inner circumferential surface of the support 32 to prevent the front part from rotating. The sleeve 44 fixed to the front end surface of the support 32 with a retaining ring 45 has a stepped portion at the rear end, and the rear end is received by this stepped portion.
A return spring 43 interposed on the outer periphery of the piston 4 is pressed against the rear end surface of the piston 40.

Further, the protrusions 48 of the mating plates 46, the protrusions 49 of the fixing plate 47, and the protrusions 41 of the piston 40 fit into the grooves 42,
The inner periphery of the desk plate 50 interposed between the mating plates 46 is movably spline-fitted to the outer periphery of a spline boss 51 having a stopper step on the piston 40 side. The spline boss 51 is spline-fitted to the outer periphery of the differential shaft 25 so as to rotate together therewith.

The retaining groove 52 fitted into the circumferential groove on the inner periphery of the rear end of the support 32 receives the fixing plate 47 in a state where the mating plate 46 and the desk plate 50 have play in the axial direction.

When assembling the above-mentioned wet desk brake and differential device 11, the piston 40 with the seal rings 38 and 39 installed is pushed into the support 32 which also serves as a cylinder, and the return spring 43 is attached to the outer periphery of the sleeve 44. At the same time, the front end of the sleeve 44 is inserted into the center hole of the support 32 while being received at the stepped portion, and the desk plate 50 is spline-fitted to the outer periphery of the retaining spline boss 51 using the retaining ring 45. 46... inserts the protrusions 48..., 49 on the outer periphery of the mating plate 46... and fixing plate 47 into the grooves 42 of the support 32 in the assembled state with the desk plate 50... held between them, and stops the outer surface of the fixing plate 47. When fixed with the ring 52, the large diameter portion of the spline boss 51 is held by the inner diameter of the desk plate 50, forming an integral structure.

The support 32 has an integral structure in this way.
are inserted into the holes drilled in the partition wall 30, and the bolts 31...
Screw it on. Thereafter, the rear differential shaft 25 of the differential device 11 is guided by the inner peripheral surface of the sleeve 44 and spline-fitted into the shaft hole of the spline boss 51.

The shift rail 53 constituting the actuator is supported by fitting the front part into the cover 28 and fitting the rear part into a circular support hole 54 bored in the side of the support 32 so as to be able to slide back and forth. A joint 55 inserted from the rear transmission 27 is inserted into a mounting hole 56 that is bored in the side of the support 32 and communicated with the rear side of the support hole 54 via an oil passage 67, and is connected to the support 32. The oil leakage is prevented by an O-ring 62 for the rear transmission 27, and an O-ring 63 for the rear transmission 27, and the support hole 5 is
4 is connected to the cylinder portion 57 into which the piston 40 is fitted through an oil passage 58, and the hole for drilling the oil passage 58 is stopped by a stopper 60 having an O-ring 59. A union bolt 66 attached to the outer end of the joint 55 via a seal is connected to a hydraulic circuit to be described later by a pipe 65.

The inner diameter of the rear part of the support hole 54 is larger than the outer diameter of the shift rail 53 so that the hydraulic oil can flow freely.
3, the support 3 is moved rearward as shown in FIG.
Oil passages 67 and 5 extend slightly inward from the inner end surface of 2.
8, and the rear portion of the notch surfaces 72, 72 is a spool portion 73, and this spool portion 73, the support hole 54, and the notch surface 72 are connected to each other. The oil passages 67 and 58 constitute a control valve that is automatically operated by hydraulic pressure, and the spacer 68 loosely fitted near the front of the shift rail 53 has its tip fitted into the circumferential groove of the sleeve 36. The forward movement position of the fork 69 is limited, and the boss portion of the fork 69 has an R groove 71 through which hydraulic oil flows out to the support 32 side.
It is fixed to the shift rail 53 by.

To explain the device for manually operating the shift rail 53, the base of the arm 74 whose tip is fitted into the receiving groove of the boss of the fork 69 is spline-fitted to the inner end of the rotating shaft 76 and stopped. ring 7
A cylindrical body 7 fixed at point 7 and into which the rotation shaft 76 is inserted
9 is inserted into the hole in the side wall of the rear transmission 27, and the plate 81 fitted in the circumferential groove 82 is screwed onto the outer surface of the rear transmission 27 with bolts 83 to position it. Uneven claw 86
and the concave and convex pawls 88 on the end surface of the boss fixed to the end of the rotation shaft 76 are engaged with each other,
One of the concave portions 86a and 88a of 6 and 88 is made deeper than the other concave portion, and a bent portion 90 at the end of the winding spring 89 is fitted into the concave and convex pawl 8.
Since the concave portions 6 and 88 are wider than the convex portions, the rotation biasing action of the winding spring 89 allows the arm 74 to move while the cylinder body 79 (concave and convex pawl 86) does not rotate as shown in FIG. Together with the rotating shaft 76 and the uneven pawl 88, a gap 90a is formed in which the rotating shaft 76 can rotate forward.

Further, a collar 9 is attached to the protruding portion of the cylinder body 79 and the outer periphery of the boss 87 to prevent it from coming off with a retaining ring 93.
2 is press-fitted, O-rings 85 and 91 are interposed to prevent oil leakage, and an O-ring 80 is also interposed between the cylinder body 79 and the rear transmission 27.

The manual operating device has an arm 84 welded to the outer periphery of the cylindrical body 79 and connected to the arm portion 102 of the operating lever 99 by a rod 94.
In this case, the lever part 103 is fitted into the receiver 95 at the tip of the arm part 102 so as to be movable forward and backward, the base is fixed with a retaining ring, and a compression spring 104 is interposed between the large diameter part 105 and the receiver 95. The guide groove 109 of the guide panel 106 has three spaced round holes communicating with each other through vertical grooves, and the round holes have a diameter that allows the large diameter portion 105 to pass through. Although the width of the groove is narrower than the diameter of the round hole, it is designed to allow the lever portion 103 to pass through. Further, the length of the rod 94 can be adjusted using nuts 100 and 101.

Further, one of the grooves 42 of the support 32 is connected to the reduction gear 107 of the sub-transmission section 4, as shown in FIG.
is approaching the bulkhead 30 of the rear transmission 27.
As shown in FIG. 8, the hole into which the support 32 is fitted is provided with a notch 108 which faces the groove 42 and has an oblique cross section, and the reduction gear 107 has a lower part at the rear. The transmission rotates while being immersed in oil in the transmission 27, stirring and discharging the oil.
Since it enters between the mating plate 46 and the disc plate 50 through the passageway, the hydraulic clutch can be easily disengaged.

Note that the winding spring 89 may be replaced by a return spring attached to the shift rail 53 or a member attached thereto.

Next, to explain the operation, when the agricultural tractor is driven by driving only the rear wheels, the control lever 9
9 is set at position A in FIG. 3, the arm 84 is pulled up as shown by the solid line in FIG.
6 and 88 are engaged and the peaks are engaged by the spring bias, so that the cylindrical body 79 and the rotating shaft 7
6. The arm 74, fork 69, and shift rail 53 are also in the position shown by solid lines, and the sleeve 36 is in the position shown in FIG. , the front wheels are not driven.

At this time, the spool portion 73 at the rear end of the shift rail 53 is in the position shown in FIG.

If you also drive the front wheels during work, hold the grip of the operating lever 99 and push it in, rotate it downward until it aligns with the second round hole from the top, and release the pushing force. position, the arm 84 is rotated downward via the rod 94, and the concave and convex pawl 86 pushes 88 counterclockwise in FIG. 4 to rotate it by a predetermined angle. Move the shift rail 53 through the fork 69 to position B in FIGS. 4 and 1.
When the sleeve 36 is moved to the state shown in FIG. 6-1, the front portion of the sleeve 36 pushes the balls 34 into the conical holes 37, so the differential shaft 25 rotates and the front wheels are driven to rotate at the standard speed.

Furthermore, when turning the machine or starting work, if the operating lever 99 is set to the front wheel speed increase standby position C in the same way as described above, the sleeve 36 also moves to the C position in the above drawings and moves to its rear part. Since the ball 34 is pushed in at the 6th part, it is in a four-wheel drive state, and the spool part of the shift rail 53 is in the 6th part.
As shown in Figure 2, the support hole 54 is closed.

Then, when the steering wheel is rotated, the detector detects that the turning angle of the front wheels exceeds the set value, and the detection signal turns on the solenoid valve a of the flow divider inserted in the hydraulic circuit shown in Figure 7. Then, the hydraulic oil pumped by the hydraulic pump P passes through the pipe 65 and the joint 55 to the support hole 54.
and pushes out the shift rail 53 until the boss portion of the fork 69 abuts the spacer 68 (the state shown in FIG. 6-3). In this process, the tapered surface at the rear of the sleeve 36 only prevents the balls 34 from coming off, but no transmission occurs, and the hydraulic oil passes through the oil passage 58 to the cylinder section 5.
7 and is pushed out by the piston 40, the mating plates 46 of the hydraulic brake are pressed against the desk plate 50, and the differential shaft 25 is stopped.
The front wheel drive shaft 24 is driven at double speed.

At this time, the arm 74 rotates following the fork 69, and the concave and convex pawl 8 of the boss 87 fixed to the outer end of the arm 74 rotates.
8 rotates within the range of the gap 90a in FIG. 4, and the cylinder 79 and each member connected thereto are stationary.

At the end of the aircraft rotation, when the steering wheel is turned back and the detector is turned OFF, the solenoid valve a switches to the state shown, the pipe 65 communicates with the rear transmission 27, and the piston 40 Since it is returned by the spring 43, the cylinder part 5
7 flows out from the oil passage 58 through the support hole 54 and the joint 55 into the pipe 65, and the shift rail 53 returns to the rear position shown in FIG. The oil directly flows out from the inner end of the support hole 54 into the rear transmission 27 through the gap formed by the cutout surface 72, and then the operating lever 99 is set to the A position and the boss of the fork 69 is moved as shown in FIG. support 32
Even if it comes into contact with the inner end surface of the R groove 71, the remaining hydraulic oil
The water then flows back into the rear transmission 27.

Furthermore, when driving straight ahead with the operating lever 99 set to the C position, if the front wheel turning angle is less than the set angle even if the driving direction is corrected, the detector will be turned OFF and the vehicle will not be able to turn at double speed. do not have.

(g) Effects of the invention Since the invention is configured as described above, the desk brake can be assembled easily, and when the differential gear 11 is assembled, the sleeve 44 is used as a guide to move the differential shaft 25. The spline boss can be fitted to the spline boss while alignment is easily and reliably performed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention,
FIG. 1 is a partial sectional view of the switching device, FIG. 2 is a cross-sectional view of the switching device, and FIG. 3 is a side view of the human operating device.
Figure 4 is a sectional view of the clutch part, Figure 5 is an expanded sectional view of the switching device, Figures 6-1, 6-2, and 6.
- Figure 3 is a sectional view showing the action of the control valve, Figure 7 is a hydraulic circuit diagram, Figure 8 is a sectional view of a part of the brake system, Figure 9 is a transmission system diagram, and Figure 10 is a side view of an agricultural tractor. It is a diagram. 11...Differential device, 24...Front wheel drive shaft, 25
... Differential shaft, 27 ... Rear transmission, 32 ...
Support, 36... Sleeve, 40... Piston, 43... Return spring, 44... Sleeve, 50... Desk plate, 51... Spline boss, 53... Shift rail, 69... Fork, 73... Spool Part, 74...Arm, 76
... Rotating shaft, 79 ... Cylindrical body, 86, 88 ... Concave and convex pawl, 89 ... Winding spring, 99 ... Operation lever.

Claims (1)

[Scope of utility model registration request] Differential device 11 that increases front wheel speed in the front wheel transmission system
The differential shaft 25 that does not output to the front wheels of the differential device 11 is connected to the support 3 mounted on the transmission case.
2, and the support 32 is used as a cylinder of the desk brake, and a piston 4 fitted therein.
A return spring 43 of 0 is supported on the outer periphery of a sleeve 44, a spline boss 51 holding the desk plate 50 on the outer periphery is fitted on the outside of this sleeve 44, and the differential shaft is spline-fitted to the spline boss 51. A front wheel speed increasing device for an agricultural tractor, characterized in that: