JPH01309823A - Front axle device of four-wheel driving tractor - Google Patents

Abstract

PURPOSE:To attain simplification of a structure by speeding up turning by rotating a front wheel in one side at two times higher speed than a rear wheel and installing a pawl crutch on both ends of an axle shaft in both sides of a front deflection so as to switch driving power transmission to the front wheels by the displacement operation. CONSTITUTION:A pressure oil is sent and supplied to a pressure oil inlet 26 at the time of turning of a tractor, a pawl crutch 18 which is inset in a front axle shaft 15 being set to slide freely is moved to the right direction by hydraulic pressure, and the pawl part 20 is let gear into a positive pin 2 projecting to the inside of an axle housing 11. The rotation of a right-side front axle shaft 15 is forcedly stopped by these processes and a left-side front axle shaft is rotated at two times higher speed than the rear wheels. The right-side wheel is let turning freely and idly by separation of the pawl crutch 18, and turning of the track is thus carried out with a small turning radius while using the left-side wheel which is braked as a fulcrum.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a front axle device for a four-wheel drive tractor, and in particular, a front axle device for a four-wheel drive tractor that rotates one front wheel at twice the speed of the rear wheel to quickly turn around. The present invention relates to a front axle device for a four-wheel drive tractor.

[Prior Art] Conventionally, when plowing is performed while reciprocating in a field with a ground-based work machine such as a rotary connected to a tractor, it is necessary to make the turning radius as small as possible when turning. be. Therefore, in a four-wheel drive tractor, the front wheels are rotated at twice the speed of the rear wheels, and the rear wheel brake is operated to reduce the turning radius and improve the turning speed. here,
The conventional technique will be explained with reference to FIG. 3 of the attached drawing. In the figure, (+) indicates a four-wheel drive tractor. A propeller shaft (3) extends rearward from the engine (2) of the four-wheel drive tractor (1) to form a center gear box (4).
has reached. And the center gear box (4)
The output is divided into two parts, one of which is the rear wheel differential (5).
and drives the rear wheels (6). Further, the output taken out from the lower part of the center gear box (4) is reversed in direction and reaches the front wheel differential (8) via the center blower shaft L-(7) arranged toward the front. . A double speed mission (9) is disposed at an appropriate position in the middle of this center propeller shaft (7).
) has a gear box with a gear ratio of 1:1 and 1:2. This double-speed transmission (9) can perform a -C gear change operation using a switch (not shown) on the driver's seat side, and when turning the tractor (1), turn on the switch. Assume that the gear ratio of the double speed mission (9) is 1=2. Then, the turning side pedal (
10) to brake the turning side rear wheel (6) and turn the turning radius to a small value. Although not shown in the drawings, there has also been proposed a vehicle in which the front and rear wheel brakes are diagonally connected without providing a double speed mixer. The operation of this mechanism is such that when the brake of the rear wheel on the turning side is activated when the vehicle is turning, the front axle on the outside in the turning direction stops rotating in conjunction with the brake. In such a case, the front and rear wheel differentials perform a differential function to rotate the opposite wheel at twice the normal speed, allowing the vehicle to turn while causing the outer front wheel to slip.

1. Problems to be Solved by the Invention] As mentioned above, the front wheel speed double mechanism in the front axle device of a conventional four-wheel drive tractor is one that is equipped with a double speed transmission, or one that connects the front and rear wheel brake devices diagonally. In the latter case, the power transmission mechanism is complicated and the cost is high, and in the latter case, since the outer front wheel is stopped when turning, the outer front wheel is dragged while turning, so the outer front wheel and The problem was that it put a strain on the axle and other parts, causing problems with durability.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a front axle device for a four-wheel drive tractor equipped with a front wheel speed doubling mechanism that has a simplified structure and a long durability.

11 Means for Solving the Problems] This invention was proposed to achieve the above object, and in a four-wheel drive tractor, a front axle shaft extending on both left and right sides of a front differential. a spline groove is provided near both ends, and a pawl clutch is provided with pawls on both sides so as to be movable in the axial direction along the spline groove, and the pawl clutches are respectively fitted into the front axle shaft; Further, a toothing portion of the claw clutch is provided at the end of the bevel gear of the final gear case fixed to the end of the front axle housing so as to transmit power, and a toothing pin is provided at an appropriate position inside the front axle housing. , so that the pawl clutch can be brought into mesh with any of the toothing portions by means such as a hydraulic mechanism, so that the pawl clutch of the turning outer front axle shaft meshes with the toothing pin when turning. It is an object of the present invention to provide a front axle device for a four-wheel drive tractor formed as described above.

[Operation] According to the present invention, spline grooves are provided near both left and right ends of the front axle shaft, and pawl clutches that can move in the axial direction along the spline grooves are respectively fitted. or,
Pawl portions are formed on both sides of this pawl clutch, making it a double-sided pawl clutch. A bevel gear is rotatably fitted to the tip of the front axle shaft into which the pawl clutch is fitted. The bevel gear meshes with a bevel gear in a final gear case fixed to both ends of the front axle housing, and a claw clutch meshing portion is provided on the side surface facing the claw clutch. Therefore,
When the pawl clutch moves outward through the spline groove, it meshes with the meshing portion of the bevel gear, and the rotation of the front axle shaft can be transmitted to the bevel gear mechanism in the final gear case to drive the front wheels. on the other hand,
Since a pin is protruded at an appropriate position inside the front axle housing, when the pawl clutch moves inward on the front axle shaft along the spline groove, it meshes with the pin and stops the rotation of the front axle shaft. let When turning, the claw clutch of the outer front axle shaft is moved by a method such as a hydraulic mechanism and meshes with the pin, and the front axle shaft is forcibly stopped, and the inner front wheel receives torque. It is transmitted to the rear wheels and rotates at twice the speed. Therefore, the turning radius can be made small and the turning can be done quickly.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2 of the attached drawings. For convenience of explanation, conventionally known techniques will also be explained at the same time. In the figure, (8) is a front wheel differential, and (10 is a front axle housing. A final gear case 02) is fixed to the end of the front axle housing OO.
J2) transmits driving force to the front wheels (yI) by a built-in bevel gear mechanism 03). Further, the front axle shaft 051 disposed inside the front axle housing O0 has one end pivotally connected to the front wheel differential (8), and the other end rotatably connected to the first bevel gear (IG) of the final gear case. The front axle shaft 09 is provided with a spline groove (■) having an appropriate length inward from the vicinity of the loosely fitting portion, and is formed so that a pawl clutch (to be described later) can be fitted therein. The spline groove (the upper wheel (hook) is provided closer to the front wheel differential (8) than the
A spline groove (2I) is provided in the shaft hole (2I) to be fitted into the front axle shaft (OS), so that the front axle shaft (OS) can be moved in the axial direction on the front axle shaft (OS). Fit the O-ring (c) into the recess provided on the outer periphery of the pawl clutch (g), and
c) is formed so as to be in sliding contact with the inside of the front axle housing θ0.

Therefore, a coil spring (2) is interposed coaxially with the front axle shaft (O5), and the pawl clutch (2) is inserted into the pawl clutch (2). Therefore, the pawl clutch moves outward along the spline groove (r7) on the front axle shaft 0!llll and presses the third clutch in the final gear case 02. 1
It meshes with the claw part (A) formed on the side of bevel gear oQ. At this time, the pawl clutch (1) and the first bevel gear (1)
10 and the front axle housing θ0 is defined as a pressure oil chamber (G).
A pressure oil inlet (4) is opened in the upper part of the pipe. facing,
When pressure oil is forced into the pressure oil inlet (4) by a hydraulic mechanism (not shown), the pawl clutch (moves in the direction of the arrow) due to the hydraulic pressure, as shown in Figure 2. , at this time, the front axle housing Ot)
A toothing pin Q' is provided protruding from the inside of the toothing pin Q', and the pawl portion (a) of the pawl clutch (g) can be meshed with the toothing pin (). Further, the hydraulic mechanism (not shown) is configured to operate in conjunction with steering operation and one brake pedal, and for example, when turning left, rotates the steering wheel to the left;
When the left rear brake pedal is pressed, the hydraulic mechanism is activated and pressure oil flows into the right pressure oil chamber (G). In such a case, the right claw clutch (Japanese Coil Spring Co., Ltd.) moves inward by the pressure δ1j against the biasing force and meshes with the toothing pin (2'/l).Therefore, the right front axle shaft 0! ;) is forcibly stopped from rotating.Therefore, due to the differential function of the front wheel differential (8), the left front axle shaft θ rotates at twice the speed of the rear wheel.

At this time, the right front wheel is disengaged from the pawl clutch and can rotate freely, and the left rear wheel is braked, so the four-wheel drive tractor (1) is driven by the left rear wheel (6). ) can be used as a fulcrum to turn left very quickly.Also,
When turning to the right, turn the steering wheel to the right and step on the right rear wheel brake. Pressure oil flows into the left pressure oil chamber and the pawl clutch moves, producing the same effect as when turning to the left. The hydraulic system is configured so that it operates only when both the steering wheel and the single brake for turning are operated, making it easier to turn the steering wheel when driving at high speeds. There is no risk that the front axle shaft will be locked due to the pawl clutch being activated accidentally when turning.In addition, an important switch is provided on the hydraulic system.
The number 114 is set to "off" when driving at high speeds to further ensure safety.

[Effects of the Invention] As detailed in the above embodiment, the present invention provides a pawl clutch on the front axle shaft, and the pawl clutch can be moved along the axis on the front axle by means such as a hydraulic mechanism. That's what I do. Since it can be meshed with either the toothing pin fixed inside the front axle 1 housing or the pawl provided on the bevel gear of the final gear case, it meshes with the bevel gear during normal driving and transmits power. and drive. Also, when turning, the pawl clutch on the outside of the turning side disengages from the bevel gear to allow the front wheel to rotate freely, and the pawl clutch meshes with the toothing pin of the front axle housing to connect the front axle shaft on the turning side. Since the front wheel is forced to stop, the front wheel on the inside of the turning wheel rotates at twice the speed due to the differential function. Therefore, turning can be performed extremely quickly. Moreover, compared to conventional models, there is no need for a transmission to double the speed of the front wheels, and since the front wheel on the inside of the turning wheel is driven at double speed, the turning speed is further improved and the turning radius can be made extremely small. Ta. In addition, when turning, the outer front wheel is separated from the front axle shaft and can rotate freely, so the external force applied to the tires and axle is reduced, improving durability and other effects. Therefore, this invention can contribute to improving work efficiency.

Therefore, this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to those modifications.

[Brief explanation of the drawing]

FIGS. 1 and 2 are partially cutaway front views of an embodiment of the present invention, each showing the operating state of the main parts. Moreover, FIG. 3 is a side view of a four-wheel drive tractor showing a conventional example. (8)...Front wheel differential (0)...Front axle housing (I2
......-Final gear case (4...Bevel gear mechanism (+59...Front axle shaft (10
・・・・・・-1st bevel gear (r7)・・・Spline groove (Japanese)・・・Pawl clutch (R7・・・・・
・・Upper ring (A)・・Claw part (C)・
...O-ring 00...Coil spring (a)...Pressure oil chamber Q゛b...---
- Teething bottle (.

Claims (1)

[Claims] In a four-wheel drive tractor, spline grooves are provided near both ends of a front axle shaft extending on both left and right sides of a front differential, and a pawl clutch having pawls on both sides is shafted along the spline grooves. The gears are formed so as to be movable in the center direction and are fitted into the front axle shafts respectively, and furthermore, a toothing portion of a pawl clutch is provided at the end of the bevel gear of the final gear case fixed to the end of the front axle housing to generate power. The pawl clutch is formed to conduct transmission, and a meshing pin is provided at an appropriate position inside the front axle housing, so that the pawl clutch can be brought into mesh with any of the meshing portions by means such as a hydraulic mechanism. A front axle device for a four-wheel drive tractor, wherein a pawl clutch of a turning outer front axle shaft meshes with the toothing pin when turning.