JP2001003946A - Cylinder shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of deformation of the tip part of spline teeth while automatically correcting a phase displacement of spline parts of both shaft from each other in a connecting process to a projecting shaft in a cylinder shaft. SOLUTION: This cylinder shaft 10, in which a projecting shaft 20 is to be spline-fitted, is provided with inclined surfaces 13 respectively having a nearly V-shaped tapered tip in both sides of the circumferential direction at a tip part of each spline tooth of a female spline part 11 provided in the inner peripheral surface of the cylinder shaft 10. The inclined surfaces 13 work so as to automatically correct a phase displacement in a process for connecting the cylinder shaft 10 and the projecting shaft 20 to each other. Furthermore, the V-shaped tip of each spline tooth is formed flat along the circumferential direction. Such a flat part 15 is hard to be crushed even if the projecting shaft 20 is interferered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical shaft used by being spline-fitted to a convex shaft. This cylindrical shaft is, for example, a shaft end portion of a one-axis body constituting a telescopic shaft, a shaft end portion of a yoke of a universal joint, or one of a drive shaft of a tractor and an input shaft of various working machines towed by the tractor. It is provided at the shaft end.

[0002]

2. Description of the Related Art Generally, for example, when two shafts are connected via a universal joint, a yoke of the universal joint and each shaft may be spline-fitted. Is a cylindrical shaft having a female spline portion on the inner peripheral surface, and a shaft end portion of the shaft body is a convex shaft having a male spline formed on the outer peripheral surface.

[0003]

By the way, in inserting the convex shaft into the above-mentioned cylindrical shaft, if the phases of the spline portions of both shafts are shifted, it becomes difficult to insert.

[0004] In order to correct the phase shift,
At present, it is troublesome to increase the number of trials or to manually insert one shaft by turning one axis by a required angle to adjust the phase.

On the other hand, the applicant of the present application has filed Japanese Patent Application No.
No. 197003 is proposed. In this application, the tip of each spline tooth of the female spline portion of the cylindrical shaft is tapered. With this configuration, in the process of connecting the convex shaft to the cylindrical shaft, when the phases of the spline portions of both shafts are shifted, the guide surface on the distal end side of the spline teeth of the cylindrical shaft generates the axial thrust of the convex shaft. The phase shift is automatically corrected by converting to a force to rotate in the circumferential direction.

By the way, in the above proposed application, a form in which the tip portion of each spline tooth is formed substantially in a V-shape in plan is presented. In this form, the correction angle of the phase shift is made as large as possible. It is sufficient that the V-shaped tooth tip is sharpened sharply, but when doing so, when the convex shaft interferes with the V-shaped tooth tip at the time of connecting the convex shaft, the cutting edge may be crushed and easily deformed. understood. There is room for improvement here.

In view of such circumstances, the present invention provides a method of automatically correcting a phase shift between spline portions of a cylindrical shaft and a spline portion during a connecting process with a convex shaft, while suppressing deformation of a tip portion of a spline tooth. The purpose is to be able to control.

[0008]

The cylindrical shaft according to the first aspect of the present invention has a convex shaft fitted with a spline, and has a circumferential portion around a tip end portion of each spline tooth of a female spline portion provided on an inner peripheral surface thereof. On both sides in the direction, there are provided slopes each of which has a tip portion having a substantially V-shaped tapered shape in plan view, and the V-shaped tip of each spline tooth is formed flat or round along the circumferential direction. .

According to a second aspect of the present invention, the flat portion or the rounded portion of the V-shaped tooth tip in the first aspect has a circumferential width set in a range of 0.5 to 3 mm.

[0010] As described above, in the cylindrical shaft of the present invention, even if the phases of the spline portions of both shafts are shifted during the connection process with the convex shaft, the slopes of the spline teeth of the cylindrical shaft generate the circumferential propulsion force of the convex shaft. Since it acts so as to convert it into a turning force in the direction, the phase shift is automatically corrected and the two shafts can be connected.

In addition, since the V-shaped tips of the spline teeth of the cylindrical shaft are formed flat or round, they are less likely to be deformed even if they interfere with the spline teeth of the convex shaft in the above-described connecting process, and the phase shift correcting action is achieved. Is stably exhibited over a long period of time.

In particular, according to the second aspect of the present invention, since the circumferential width of the flat portion or the round portion of the V-shaped tooth tip is specified,
The correction angle of the phase shift of the convex shaft can be ensured as large as possible in the process of coupling with the convex shaft, and even if the convex shaft interferes, it is hardly damaged.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

1 to 3 show one embodiment of the present invention. FIG. 1 is a longitudinal side view of a cylindrical shaft, FIG. 2 is a perspective view showing a cylindrical shaft and a convex shaft, and FIG. 3 is an explanatory diagram showing a phase shift correction mode in a connecting process between the cylindrical shaft and the convex shaft. is there.

In the drawing, reference numeral 10 denotes a cylindrical shaft, and reference numeral 20 denotes a convex shaft. The convex shaft 20 is connected to the cylindrical shaft 10 by spline fitting so as to be slidable in the axial direction and synchronously rotated in the circumferential direction.

The cylindrical shaft 10 is formed in a cylindrical shape, and a female spline portion 11 is formed on an inner peripheral surface thereof. A diameter-enlarged tapered surface 12 is formed at one open end of the inner peripheral surface of the cylindrical shaft 10.

The convex shaft 20 is formed in a cylindrical shape, and a male spline portion 21 is formed on an outer peripheral surface thereof. For example, a tapered surface 22 is formed at the tip of each spline tooth of the male spline portion 21 of the convex shaft 20.

On both circumferential sides of the distal end of each spline tooth of the female spline portion 11 of the cylindrical shaft 10, slanted curved slopes 13 are formed, and the shape of the distal end of the spline tooth is formed. Is almost V in plan view
It is formed in the shape of a letter. In the above-described slope 13, two slopes 13 located on the spline groove side, respectively.
Are paired to form a mortar-like shape.

Further, a region on the tip end side of each spline groove of the female spline portion 11 on the enlarged diameter tapered surface 12 of the cylindrical shaft 10 is connected to the pair of two inclined surfaces 13 located on the above-described spline groove side. A fan-shaped depression 14 is formed.

Further, the V-shaped tip of each spline tooth described above is not sharply pointed but formed flat along the circumferential direction. This flat portion is referred to as a flat portion 15. The circumferential width B of the flat portion 15 is set in the range of 0.5 to 3 mm, preferably 1 mm. The flat portion 15 may have a rounded R surface.

The two pairs of slopes 13, 13 formed at the tip of the above-described spline groove and the depression 14 serve as a guide surface for correcting a phase shift when the convex shaft 20 is connected.

Next, a method of processing the female spline portion 11 of the cylindrical shaft 10 will be described.

That is, a rotary turning tool 40 described later.
As shown in FIG. 4, the rotary turning tool 40 is rotated while rotating the rotary turning tool 40 in a state in which the tip is applied to the tip of one spline groove while the tip is in a position along the axis of the cylindrical shaft 10. Move. As a result, the one-sided corners of the two spline teeth on both sides of the spline groove are chamfered at the same time in an obliquely curved shape, and as a result, a pair of two slopes 13 are formed at the tip of the spline groove. A guide surface including the depression 14 is formed.
Thereafter, the above-described processing is performed on all spline teeth. As a result, the above-described guide surface is formed at the tip of the spline groove, the shape of the tip of each spline tooth is substantially V-shaped in plan view, and the V-shaped tooth tip has a flat portion 15 of a required width. Will remain.

As the rotary turning tool used for such processing, various commonly known end mills, drills, and the like can be modified.

Specifically, a rotary turning tool 40 as shown in FIGS. 5 to 7 is used. This rotary turning tool 40 has two
It has a shape based on a blade-type end mill and a reduced diameter portion 41 provided on the tip side of the blade portion.

With respect to the rotary turning tool 40 prepared here, the diameter R of the rotary arc locus of the blade portion and the diameter reduction portion 4
The axial length W and the inclination angle θ of the reduced diameter portion 41 need to be defined as described below.

First, as shown in FIG. 8, the diameter dimension R of the above-described rotary arc locus is determined by a guide surface (a pair of two slopes 13 and a depression 14) formed at the tip of each spline groove of the cylinder shaft 10. ) Is set to be the same as the diameter r of the virtual arc X passing through the three points P1, P2, and P3. The axial length W of the reduced diameter portion 41 is set to be equal to or larger than the axial length L of the slope 13 as shown in FIG. Further, the inclination angle θ of the reduced diameter portion 41 is set to be the same as the angle α of the V-shaped tip of the spline teeth.

In the case of the cylindrical shaft 10 described above, in the connecting process with the convex shaft 20, the axes of the shafts 10 and 20 are shifted or the spline portions 11 and 21 of the shafts 10 and 20 are connected. Even if the phase is shifted, the center shift and the phase shift are automatically and smoothly corrected without any trouble as described below.

First, when the axes of both shafts 10 and 20 are deviated, the tapered surface 12 of the cylindrical shaft 10 and the taper of the spline teeth of the convex shaft 2 are accompanied by the operation of abutting the shafts 10 and 20. When the surface 22 abuts, the enlarged taper surface 12 of the cylindrical shaft 10 acts so as to convert the axial propulsion force of the convex shaft 20 into a force to be displaced in the radial direction. The center coincides with the axis of the convex shaft 20.

Each spline section 1 of both shafts 10 and 20
When the phases of the shafts 1 and 21 are out of alignment, the female spline portion 1
When the tooth tip of the male spline portion 21 of the convex shaft 20 comes into contact with the first inclined surface 13, the inclined surface 13 acts so as to convert the axial propulsive force of the convex shaft 20 into a force for turning in the circumferential direction. Therefore, the convex shaft 20 is rotated by a required angle, so that the phase of the male spline portion 21 matches the phase of the female spline portion 11. Since the rotation of the convex shaft 20 in this phase correction operation is guided while the spline teeth of the male spline portion 21 slide along the obliquely curved slope 13 of the female spline portion 11,
Become smooth.

As described above, in the process of connecting the cylindrical shaft 10 and the convex shaft 20, in particular, the spline portions 1
Even if the phases 1 and 21 are shifted, this phase shift can be automatically corrected, so that the connection can be performed simply and quickly without the need for the operator's hand as in the related art.

In addition, since the flat portion 15 is provided at the V-shaped tip of the spline teeth of the cylindrical shaft 10, even if it interferes with the spline teeth of the convex shaft 20 in the above-described connecting process, it is difficult to deform. The phase shift correction operation can be stably exhibited over a long period of time.

In particular, as in this embodiment, the flat portion 15
If the circumferential width B is specified as small as possible, the angle of correction of the phase shift of the convex shaft 20 during the connection process with the convex shaft 20 can be as large as possible. 20
However, even if interference occurs, it is less likely to be damaged, so that reliability can be improved.

By the way, the cylinder shaft 10 of the above-described embodiment is
Is a drive shaft 2a of the tractor 2 as shown in FIG.
Can be used as a coupling for connecting the input shaft 3a of the working machine 3 having a convex shaft shape. Specifically, the cylindrical shaft 10 is integrally provided at the shaft end of one yoke 2c of the cross joint 2b attached to the free end of the drive shaft 2a of the tractor 2.

In the example shown in FIG. 10, the drive shaft 2a of the tractor 2 and the input shaft 3a of the work machine 3 are arranged on the tractor 2 side so that the input shaft 3a can be automatically connected without human intervention. Arm unit A that is installed and draws work machine 3
A locking unit B disposed on the work machine 3 side and locked by the arm unit A; and an arm unit A of the tractor 2
And a support unit C that supports the one yoke 2c of the cross joint 2b so as to be tiltable and radially displaceable in a rotatable state in a substantially horizontal posture.

As shown in FIG. 11, for example, the support unit C includes an annular frame 4 fixed to the arm unit A of the tractor 2, a self-aligning ball bearing 5 attached to the annular frame 4, It comprises three coil springs 6 which hold the aligning ball bearing 5 at a position substantially at the center of the annular frame 4. The annular frame 4 includes a pair of annular plates 4a and 4b.
And an inner cylinder 4c and an outer cylinder 4d disposed between the annular plates 4a and 4b and arranged radially inward and outward. Inner cylinder 4c
Are slidable in the radial direction. Circumference 3 of outer cylinder 4d
Three hollow bolts 4e for adjusting the amount of compression of the coil spring 6 are screwed into the places.

If the cylinder shaft 10 of the present invention is used as such a coupling for connecting the tractor 2 and the working machine 3, the phase shift correction function of the cylinder shaft 10 of the present invention becomes extremely effective, and 2 can be greatly contributed to further smooth connection operation between the drive shaft 2a and the input shaft 3a of the work machine 3.

[0038]

In the cylindrical shaft according to the first and second aspects of the present invention, even if the phases of the spline portions of both shafts are shifted at the time of connection with the convex shaft, the phase shift can be reduced only by abutting these two shafts. Since the correction can be made automatically, the number of trials can be reduced, and the connection can be made without any trouble. In addition, since the V-shaped tip of the spline teeth of the cylindrical shaft is formed flat or round, the spline teeth of the cylindrical shaft are less likely to be deformed even if they interfere with the spline teeth of the convex shaft in the above-described connecting process, and the phase shift correction effect is obtained. It can be stably exhibited over a long period of time.

In particular, according to the second aspect of the present invention, since the circumferential width of the flat portion or the round portion of the V-shaped tooth tip is specified,
Contribution to the improvement of reliability, such as making it possible to secure as large a correction angle for the phase shift of the convex shaft as possible in the process of connecting with the convex shaft, and making it less likely to be damaged even if the convex shaft interferes. become able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a cylinder shaft according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a cylindrical shaft of FIG. 1 and a convex shaft of a connecting partner thereof.

FIG. 3 is an explanatory diagram showing a phase shift correction mode in the process of connecting the cylindrical shaft and the convex shaft of FIG. 1;

FIG. 4 is a longitudinal sectional side view showing a processing form of the cylindrical shaft of FIG. 1;

FIG. 5 is a perspective view showing a rotary turning tool used for machining the cylindrical shaft of FIG. 1;

FIG. 6 is a side view of the rotary turning tool of FIG. 5;

FIG. 7 is an end view of the rotary turning tool of FIG. 5;

FIG. 8 is an explanatory view showing one element of design conditions of a rotary turning tool used for machining the cylinder shaft of FIG. 1;

FIG. 9 is an explanatory view showing other elements of the design conditions of the rotary turning tool used for machining the cylindrical shaft of FIG. 1;

10 is a side view showing an example in which the cylinder shaft of FIG. 1 is used as a coupling for connecting a tractor and a working machine.

FIG. 11 is a longitudinal sectional side view showing the support unit in FIG. 10;

[Explanation of symbols]

 Reference Signs List 10 cylindrical shaft 11 female spline portion of cylindrical shaft 13 slope of female spline portion 14 concave portion of female spline portion 15 flat portion of spline teeth 20 convex shaft 21 male spline portion of convex shaft

Claims (2)

[Claims] A convex shaft is a cylindrical shaft to be spline-fitted, and the distal end portion is substantially V-shaped on both sides in the circumferential direction of the distal end portion of each spline tooth of a female spline portion provided on the inner peripheral surface thereof. A cylindrical shaft provided with slopes each having a tapered shape of a letter shape, and a V-shaped tip of each spline tooth is formed flat or round in a circumferential direction. 2. The cylindrical shaft according to claim 1, wherein the flat portion or the round portion of the V-shaped tooth tip has a circumferential width of:
A cylindrical shaft set within a range of 0.5 to 3 mm.