JPH06200992A - Differential lock device - Google Patents

Abstract

PURPOSE:To smoothly detach engaging teeth from teeth to be engaged at releasing differential lock, even if the friction force of meshing faces of the engaging teeth and the teeth to be engaged during turning, or the like. CONSTITUTION:A differential lock shifter 15 is provided on an output shaft 8L projected from a differential device 2 movably in the axial direction and rotationally movably in one body with the shaft, and engaging teeth 16 are projectingly provided toward a differential case 4 on the face of the shifter 15 opposed to the differential case 4 of a differential device 2 in the axial direction of the output shaft 8L. Further, teeth 13 to be engaged with the engaging teeth 16 by moving the differential lock shifter 15 on the differential device 2 side are provided on the differential case 4 projecting toward the differential lock shifter 15, and the meshing faces contacting with each other at engaging the engaging teeth 16 with the teeth 13 to be engaged, are formed into taper faces tapering in the projecting direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diff lock device used in vehicles such as tractors.

[0002]

2. Description of the Related Art In a tractor, power from an engine is input to a differential device, from which power is transmitted to left and right drive wheels via left and right output shafts.
It is equipped with a diff lock device that integrally rotates the left and right drive wheels. As the diff lock device, a differential lock shifter provided on the output shaft so as to be movable in the axial direction and integrally rotatable is provided with engaging teeth on the surface facing the differential device in the axial direction of the output shaft. The differential gear shifter is moved toward the differential gear side so as to integrally rotate the left and right output shafts on the differential gear side so that the engaged tooth that meshes with the engaging tooth becomes a differential lock shifter. There is something protruding toward.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the above-mentioned conventional clutch lock type diff lock device, the left and right sides are in the diff lock state (the engagement teeth and the engaged teeth are in mesh). When the drive wheels have a differential torque (such as when the tractor is turning), the frictional force of the meshing surfaces of the engaging teeth and the engaged teeth that come into contact during meshing becomes large, and when the differential lock is released There is a problem that it is difficult for the claw to separate from the engaged claw.

Therefore, the present invention has been made so that the engaging tooth can be smoothly separated from the engaged tooth even when the frictional force of the meshing surfaces of the engaging tooth and the engaged tooth is large, such as during turning. The purpose is to do.

[0005]

The technical means taken by the present invention to achieve the above-mentioned object is to output the output shafts 8L, 8R from the differential device 2 to the left and right, and to the output shaft 8L, the differential lock. The shifter 15 is provided so as to be movable in the axial direction and integrally rotatable, and the output shaft 8L of the differential lock shifter 15 is
The engaging teeth 16 are provided on the surface facing the differential device 2 in the axial direction.
Is provided so as to project toward the differential device 2 and the differential lock shifter 15 is moved to the differential device 2 side in order to integrally rotate the left and right output shafts 8L and 8R toward the differential device 2 side. In the diff lock device in which the engaged teeth 13 that mesh with the mating teeth 16 project toward the diff lock shifter 15, the mating surfaces 29 and 30 of the engaging teeth 16 and the engaged teeth 13 that come into contact with each other when mating are provided. The point is that it is formed on a tapered surface that tapers in the protruding direction.

Of the engaging teeth 16 or the engaged teeth 13,
The root side edge 31 of one meshing surface 29 is matched with a line segment passing through the output shaft 8L axis, and the tooth top side edge 32 of the other meshing surface 30 is changed into a line segment passing through the output shaft 8L axis. It is preferable to match.

[0007]

By moving the differential lock shifter toward the differential gear, the engaging teeth are engaged with the engaged teeth to be differentially locked, and by moving the differential lock shifter away from the differential gear, the engaging teeth are locked. The differential lock is released by separating from the engaging teeth. Even when the frictional force of the meshing surfaces is large, such as during turning, when the diff lock is released, the engaging teeth are smoothly separated from the engaged teeth by the guiding action of the tapered surfaces of both meshing surfaces.

Further, according to a second aspect of the present invention, among the engaging teeth or the engaged teeth, one of the meshing surfaces of one of the engaging teeth is made to have a root side edge thereof aligned with a line segment passing through the output shaft axis, and the other is By aligning the tip side edge of the meshing surface with the line segment passing through the output shaft axis, both meshing surfaces can be matched well.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a mission case that constitutes a vehicle body of a tractor, and a differential device 2 that transmits power from an engine to left and right rear wheels is housed inside the mission case. This differential device 2 includes a differential case 4 to which an input gear 3 is attached and fixed, two differential pinion shafts 5 supported in the differential case 4 in a cross shape, and a pair rotatably supported by each differential pinion shaft 5. The differential pinion 6 and a pair of left and right differential side gears 7 meshing with the differential pinion 6 are provided, and the output shafts 8L and 8R project from the differential device 2 to the left and right.

Cylindrical support parts 9 are provided on both left and right sides of the differential case 4.
L and 9R are formed, and each of the support portions 9L and 9R is a cylindrical support body 1 that is attached and fixed to the left and right side walls of the mission case 1.
It is rotatably supported on the left and right inner ends of 0L and 10R via bearings 11L and 11R so as to be rotatable around the axis in the left and right direction. The inner end sides of the left and right output shafts 8L, 8R are passed through the left and right supports 10L, 10R to support the left and right support parts 9 of the differential case 4.
The L side and 9R are inserted and spline-fitted to the differential side gear 7.

The left and right outer ends of the output shafts 8L and 8R are linked to the rear wheels via a hydraulic disc brake device 12, a final reduction gear device, and the like. As shown in FIG. 2, engaged teeth 13 are formed on the left-right outer end surface of the left supporting portion 9L of the differential case 4. Further, a diff lock shifter 15 is spline-fitted to the spline portion 14 of the left output shaft 8L so as to be axially movable and integrally rotatable.
5, a flange portion 15a is provided on the inner side in the left-right direction,
Engaging teeth 16 that mesh with the engaged teeth 13 are formed on the surface of the flange portion 15a that faces the outer end surface in the left-right direction of the support portion 9L.

The inner peripheral surface of the left support 10L is formed in a step-like manner so that the diameter gradually increases from the left to the right. (Hereinafter, the inside of the support 10L is sequentially arranged from the right side to the first, second, third, fourth fitting holes 17a, 17b, 17c, 17d
Call. ) Then, the differential case 4 is inserted into the first fitting hole 17a.
The bearing 11L externally fitted to the support portion 9L is internally fitted. An annular piston 18 and a collar 19 are fitted in the support 10L from the right side.

A projecting portion 20 is formed on the outer peripheral surface of the piston 18 in the left-right direction intermediate portion over the entire circumference.
0 is slidably fitted in the third fitting hole 17c, the left side portion of the piston 18 is slidably fitted in the fourth fitting hole 17d, and the left end surface of the protrusion 20 and the third fitting An annular lock-side oil chamber 21 is formed between the left end surface of the fitting hole 17c. In the lock side oil chamber 21, the oil passage 2 formed in the support 10L is provided.
2 and pressure oil is supplied through a hydraulic pipe 23 or the like connected to the oil passage 22.

On the right end side of the inner peripheral surface of the piston 18, a shifter engaging portion 24 is formed so as to project radially outward over the entire circumference, and the shifter engaging portion 24 is formed on the flange portion 15a of the differential lock shifter 15. A ring body 26 fixed to the diff lock shifter 15 is brought into contact with the rear surface of the shifter engaging portion 24 via a needle bearing 25.

The outer peripheral surface of the collar 19 is formed in a stepped shape, the right half portion is slidably fitted in the second fitting hole 17b, and the left half portion is the third fitting hole 17c and the piston 18. It is internally fitted so that it can move relative to the right end side. An annular return-side oil chamber 27 is formed between the protruding portion 20 of the piston 18 and the collar 19. The return-side oil chamber 27 is connected to the oil passage formed in the support body 10L and the oil passage. The pressure oil is supplied through the hydraulic pipe or the like. The collar 19 is retained by a retaining ring 28.

Engagement teeth 13 formed on the differential case 4
As shown in FIGS. 3 and 4, a plurality (six in the illustrated example) of the output shaft 8L is provided so as to project from the lateral outer end surface of the support portion 9L to the output shaft 8L axial direction differential lock shifter 15 side.
They are formed at equal intervals on a circumference centered on the L axis. Further, as shown in FIGS. 5 and 6, the engagement teeth 16 formed on the diff lock shifter 15 have a flange portion 15a.
Of the output shaft 8 from the surface facing the outer end surface in the left-right direction of the support portion 9L.
A plurality (six in the illustrated example) of a plurality of protrusions are provided on the side of the differential case 4 in the direction of the L-axis, and are formed at equal intervals on a circumference centered on the L-axis of the output shaft 8 like the engaged teeth 13. ing.

The engaging surfaces 29 and 30 of the engaging teeth 16 and the engaged teeth 13 which come into contact with each other when they engage with each other are formed as tapered surfaces which taper in the protruding direction. Then, the engaged tooth 1
The tooth root side edge 31 of the meshing surface 29 of No. 3 is aligned with the line segment passing through the output shaft axis, and the tooth tip side edge 32 of the meshing surface 30 of the engaging tooth 16 is line passing through the output shaft axis. The angle of inclination of the taper of both meshing surfaces 29, 30 (20 ° in the illustrated example) is also formed in the same manner, and both meshing surfaces 29, 30
Are in surface contact.

In the above structure, in order to differential lock,
From the state shown in FIGS. 1 and 2, the solenoid valve is operated by, for example, a manual switch operation (or an automatic switching operation by a sensor), and the pressure oil is supplied to the lock side oil chamber 21 via the solenoid valve and returned. The oil in the side oil chamber 27 is drained. Then, the piston 18 moves toward the differential case 4 side, whereby the differential lock shifter 15 is pushed and the engaging teeth 16 are engaged.
The differential case 4 and the output shafts 8L and 8R rotate integrally with each other, and the differential device 2 is locked.

To release the diff lock, pressure oil is supplied from the above state to the return side oil chamber 27 and the valve is switched so that the oil in the lock side oil chamber 21 is drained, whereby the diff lock shifter 15 is returned. The engaging teeth 16
Is separated from the engaged tooth 13 and the differential lock is released.
At this time, the meshing surfaces 29, 3 of the engaging teeth 16 and the engaged teeth 13
Even if the frictional force of 0 is large, the engaging teeth 16 are smoothly separated from the engaged teeth 13 by the guiding action of the tapered surfaces of the meshing surfaces 29 and 30.

FIG. 7 shows a differential device 2 for the front wheels. This differential device 2 for the front wheels is a differential device 2 for the rear wheels.
Is a double-action type in which the piston 18 is returned by hydraulic pressure, whereas the piston 18 is returned by a return spring 33 composed of a coil spring. The rest of the configuration is substantially the same as that of the rear wheel differential device 2. The same components as those of the rear wheel differential device 2 are designated by the same reference numerals and description thereof will be omitted.

The differential lock for the front wheel differential 2 and its release can be controlled by a controller (not shown) so that the differential lock 2 and the release of the differential lock can be performed simultaneously with the rear wheel differential 2.

[0022]

According to the present invention, the engaging teeth of the diff lock shifter and the engaged teeth of the diff case are tapered so that the meshing surfaces that come into contact with each other when meshing are tapered toward the protruding direction. Since it is formed on the surface, even if the frictional force of the meshing surfaces is large, such as when the diff lock is released or during turning, the engaging teeth are smoothly separated from the engaged teeth by the guiding action of the tapered surfaces of both meshing surfaces. To do.

Further, as described in claim 2, among the engaging teeth or the engaged teeth, the root side edge of one meshing surface is made to coincide with the line segment passing through the output shaft axis, and the other By matching the tip end side edge of the meshing surface with the line segment passing through the output shaft axis, both meshing surfaces can be matched well.

[Brief description of drawings]

FIG. 1 is a rear cross-sectional view showing the whole.

FIG. 2 is an enlarged cross-sectional view of a main part.

FIG. 3 is a left side view of the differential case.

FIG. 4 is a sectional view taken along the line AA of FIG.

FIG. 5 is a right side view of the diff lock shifter.

FIG. 6 is a sectional view taken along the line BB-B in FIG.

FIG. 7 is a cross-sectional view of a main portion showing a front wheel differential device.

[Explanation of symbols]

 2 Differential device 8L Output shaft 8R Output shaft 13 Engaged tooth 15 Diff lock shifter 16 Engaging tooth 29 Engagement surface 30 Engagement surface 31 Root side edge 32 Tip side edge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Yoshikawa 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (2)

[Claims] 1. An output shaft (8) from the differential device (2) to the left and right.
L) and (8R) are projected, and a diff lock shifter (15) is provided on the output shaft (8L) so as to be axially movable and integrally rotatable, and the diff lock shifter (15) has an output shaft (8L). ) Engaging teeth (16) are provided on a surface facing the differential device (2) in the axial direction so as to project toward the differential device (2), and the left and right output shafts are provided on the differential device (2) side. (8
L) and (8R) are integrally rotated, the differential lock shifter (15) is moved to the differential device (2) side to engage the engaged tooth (16) with the engaged tooth (13). In the diff lock device projecting toward the shifter (15), the engagement surfaces (29), (30) of the engagement tooth (16) and the engaged tooth (13) that come into contact with each other in the engagement direction are projected. A diff lock device characterized in that it is formed on a taper surface that tapers toward. 2. A line segment that passes through a root side edge (31) of one meshing surface (29) of the engaging teeth (16) or the engaged teeth (13) and passes through the axis of the output shaft (8L). In addition, the tip end side edge (32) of the other meshing surface (30) is output shaft (8L).
The line segment passing through the axis is matched.
The differential lock device described.