JP3600813B2 - Needle roller compression device and needle roller compression method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the manufacture of a needle roller used for a bearing or the like.
[0002]
[Prior art]
Normally, the needle roller used for bearings and the like has a cross-sectional shape of a perfect circle in order to allow smooth rotation, and the contact resistance of the end when the needle roller rotates skewly. In order to reduce it, an inclined surface having a curvature at its end is formed.
[0003]
Such a needle roller is generally manufactured by the following steps.
[0004]
First, as shown in FIG. 4, concave portions 65 and 75 are provided in advance in the punch 6 and the die 7 of the header device 5 facing each other, and the bottom portions 61 and 71 and the side portions 62 and 72 of the concave portions 65 and 75 are formed. Curved inclined surfaces 66 and 76 having a constant curvature are formed in the outer peripheral portion of the boundary. Then, the needle roller 4 is attached to the concave portions 65 and 75 of the punch 6 and the die 7, and the needle roller 4 is compressed in the axial direction. The inclined surface 40a is formed. Then, the punch 6 and the die 7 are separated from each other, the pins 64 and 74 are projected from the left and right through holes 63 and 73, and the needle roller 4 is taken out. It is scraped off by trimming, and the cross section is made into a perfect cylinder by polishing.
[0005]
[Problems to be solved by the invention]
By the way, when the needle roller 4 is compressed to form the inclined surface 40a at the end portion 40, as shown in FIG. 5, the point A of the inclined surface 76 curved from the side surface portion 72 in the concave portion 75, that is, as shown in FIG. At a point where the inclination angle θ from the side surface 72 toward the inside is up to 45 degrees, a compressive force acts in the direction of forming the inclined surface 40 a on the end 40 of the needle roller 4. That is, a compression force that buckles the needle roller 4 in the axial direction acts on the portion where the inclination angle θ inward from the side surface portion 72 exceeds 45 degrees, and as shown in FIG. In this case, a depression 40c and asymmetric curved portions 40a and 40b are formed in the center of the end portion.
[0006]
Further, when a high compressive force is applied in the axial direction of the needle roller 4 in this manner, the wapper 43 generated at the central portion of the needle roller 4 becomes large, and the use efficiency of the finished product with respect to the material deteriorates. Further, in the case where the wiper 43 is scraped off by trimming, it is preferable to reduce the amount of polishing by scraping off the cut surface as shown by the line aa in FIG. In this case, the cutting blade 8 slides away from the curved portion, and as a result, the entire edge of the wapper 43 is removed to form a recessed portion 44.
[0007]
Therefore, the present invention has been made in view of such a problem, and an object of the present invention is to provide a device capable of forming an inclined surface at an end of a needle roller without causing buckling or the like. is there.
[0008]
[Means for Solving the Problems]
That is, the present invention, in order to solve the above-mentioned problem, in a configuration in which an inclined surface is formed at the outer peripheral portion of the boundary between the end portion and the side portion of the needle roller by compressing the needle roller in the axial direction, At the boundary between the bottom surface and the side surface of the concave portion for fitting and compressing the roller, an inclined surface having a range not exceeding 45 degrees with respect to the axial direction of the fitted needle roller is provided, and the range of the inclined surface is provided. The needle roller fitted in the recess in the inside is compressed in the axial direction.
[0009]
As described above, since the needle roller is compressed within a range not exceeding 45 degrees with respect to the axial direction, excessive compression in the axial direction can be reduced to prevent buckling. And asymmetrical curved portions are not generated, and a large protrusion of the wapper can be prevented.
[0010]
Further, such an inclined surface is constituted by a tapered surface which is linearly inclined from the side surface portion to the bottom surface portion.
[0011]
With such a structure, by contacting the end of the needle roller with the linear tapered surface, the inclined surface is uniformly formed at the boundary of the end regardless of the outer diameter dimension difference between the concave portion and the needle roller. Will be able to
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a main part of a punch 2 and a die 3 of a header device 1 which is a needle roller compression device of the present invention, and FIG. 2 is an enlarged view of a concave portion 35 of the die 3. Things. FIG. 3 shows a compression process of the needle roller 4 attached to the punch 2 and the die 3.
[0013]
The header device 1 compresses a punch 2 and a die 3 for forming inclined surfaces 41 at both end portions 40 of the needle roller 4 and a needle roller 4 fitted in the punch 2 and the die 3 along the axial direction thereof. And a compression mechanism (not shown). The punch 2 and the die 3 are provided with concave portions 25 and 35 having an inner diameter substantially equal to the diameter of the extruded needle roller 4, and are provided in the concave portion 25 provided in the punch 2 and the die 3. The recesses 35 are provided on the same axis so that the openings 26 and 36 face each other. Further, through holes 23 and 33 are provided in the bottom portions 21 and 31 of the punch 2 and the die 3 so that the pins 24 and 34 can protrude toward the concave portions 25 and 35, and the compressed needle roller 4 is taken out. At this time, the pins 24, 34 protrude from the through holes 23, 33 of the punch 2 or the die 3 to which the needle roller 4 is attached so that the needle roller 4 can be removed. On the other hand, the compression mechanism drives the punch 2 side by driving means such as a driving motor so that the needle roller 4 fitted in the punch 2 or the die 3 can be compressed in the axial direction.
[0014]
In this embodiment, tapered surfaces 26 and 36 that are linearly inclined are provided at the boundaries between the bottom surfaces 21 and 31 and the side surfaces 22 and 32 of the punch 2 and the die 3 in this embodiment.
[0015]
The tapered surfaces 26 and 36 are provided over the entire periphery of the boundary between the bottom surfaces 21 and 31 and the side surfaces 22 and 32, and have an inclination angle of approximately 45 degrees or less along the axial direction of the recesses 25 and 35. Preferably, an inclination angle of 30 degrees to 40 degrees is provided so that the distance between the tapered surfaces 26 and 36 facing the bottom surfaces 21 and 31 is gradually reduced. The length of the tapered surfaces 26 and 36 in the axial direction is determined according to the interval between the bottom surfaces 21 and 31 of the punch 2 and the die 3 at the time of the most compression, and when the punch 2 is moved to the closest to the die 3 side. The length is set so that both end portions 40 of the needle roller 4 are located on the respective tapered surfaces 26 and 36.
[0016]
On the other hand, the compression mechanism drives the punch 2 so that the compression process is completed in a state where the outer wall surfaces 27 and 37 of the punch 2 and the die 3 are separated from each other. The surface 41 is formed, and a compressive force that does not cause buckling of the needle roller 4 is applied to the needle roller 4 from the bottom surfaces 21 and 31 of the punch 2 and the die 3.
[0017]
Next, a process of forming the inclined surface 41 on the end portion 40 of the needle roller 4 using the header device 1 configured as described above will be described.
[0018]
First, the needle roller 4 formed into a cylindrical shape by extrusion molding is fitted into a concave portion 35 formed in the die 3 of the header device 1 (FIG. 3A), and a compression mechanism is driven by operating a switch (not shown). Then, the punch 2 is moved to the die 3 side. With this movement, the other end portion 40 of the needle roller 4 protruding from the die 3 side is fitted into the concave portion 25 side of the punch 2 and further compressed, whereby the tapered surfaces 26 and 36 of the concave portions 25 and 35 are added. The boundary portions between the both end portions 40 and the side surface portions 42 of the needle roller 4 are pressed to cause plastic deformation (FIG. 3B).
[0019]
Due to this plastic deformation, the boundary between the both end portions 40 and the side surface portion 42 of the needle roller 4 forms the inclined surface 41 along the tapered surfaces 26 and 36, but the axis added from the tapered surfaces 26 and 36 of the concave portions 25 and 35. A wapper 43 is generated between the outer wall surfaces 27 and 37 by the compressive force in the direction and the compressive force from the bottom surfaces 21 and 31. By operating a switch (not shown), the punch 2 and the die 3 are separated from each other to remove the washer 43, and the pins 24, 34 are protruded from the through holes 23, 33 on the side where the needle roller 4 is attached. 4 is taken out, and the swollen wappers 43 are removed by polishing or the like (FIG. 3C).
[0020]
In the experiment, when a steel needle roller having a diameter of 2.0 mm and an axial distance of 6.9 mm was compressed to 6.7 mm by the header device 1, the wapper 43 formed between the outer wall surfaces 27 and 37 was It only swells slightly, and the cross section can be made into a perfect circular shape by polishing without scraping the wapper 43 with a cutting blade.
[0021]
As described above, in the above-described embodiment, the needle roller 4 is compressed in the axial direction to form the inclined surface 41 at the boundary between the end portion 40 and the side surface portion 42 of the needle roller 4. A slope not exceeding 45 degrees with respect to the axial direction of the needle roller 4 or the concave portions 25, 35 is provided at a boundary between the bottom surfaces 21, 31 of the concave portions 25, 35 for fitting the roller 4 and the side surfaces 22, 32. Since the needle roller 4 is compressed in the axial direction within the range of the inclination, the buckling can be prevented, and the protrusion of the wapper 43 can be prevented.
[0022]
In addition, since the inclination is constituted by the tapered surfaces 26 and 36 that are linearly inclined from the side surface portions 22 and 32 to the bottom surface portions 21 and 31, there is a case where the diameters of the needle roller 4 and the concave portions 25 and 35 are different. However, the inclination angle of the needle roller 4 can be made uniform.
[0023]
The specific configuration of each unit is not limited to only the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
[0024]
For example, in the above embodiment, the inclined portions of the concave portions 25 and 35 are constituted by the tapered surfaces 26 and 36, but the present invention is not limited to this. For example, this inclination may be constituted by a curved inclined surface having a maximum inclination angle of 45 degrees or less.
[0025]
【The invention's effect】
According to the present invention, in a configuration in which an inclined surface is formed at the boundary between the end portion and the side portion of the needle roller by compressing the needle roller in the axial direction, the bottom portion of the concave portion for fitting the needle roller is provided. An inclined surface that does not exceed 45 degrees with respect to the axial direction of the needle roller or the concave portion is provided at a boundary portion of the side surface portion, and the needle roller fitted into the concave portion is compressed in the axial direction within the range of the inclined surface. Therefore, buckling in the axial direction can be prevented, and large protrusion of the wapper can be prevented.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of a header device showing one embodiment of the present invention.
FIG. 2 is an enlarged view of the vicinity of a bottom portion in the same embodiment.
FIG. 3 is a diagram showing a compression process of a needle roller in the same embodiment.
FIG. 4 is a sectional view of a main part of a conventional header device.
FIG. 5 is an enlarged view of the vicinity of a bottom portion of a conventional header device.
FIG. 6 is a view showing a compression process of a needle roller in a conventional example.
[Explanation of symbols]
1 ... Needle roller compression device (header device)
4 Needle rollers 21, 31 Bottom part 22, 32 Immediate surface part 25, 35 Depressed part 26, 36 Sloped surface (tapered surface)
40 ... End 42 ... Side

Claims (4)

A concave portion for fitting the end portion of the needle roller, and a needle roller compression device comprising a compression mechanism for compressing the needle roller fitted in the concave portion in the axial direction,
An inclined surface that does not exceed 45 degrees with respect to the axial direction of the concave portion is provided at a boundary portion between the bottom surface portion and the side surface portion of the concave portion, and the needle roller fitted into the concave portion is axially compressed within the range of the inclined surface. A needle roller compression device, wherein an inclined surface is formed at a boundary outer peripheral portion between an end portion and a side surface portion of the needle roller. The needle roller compression device according to claim 1, wherein the inclined surface is a tapered surface that is linearly inclined from a side surface portion. A recess for fitting the end of the needle roller, and a compression mechanism for compressing the needle roller fitted in the recess in the axial direction are provided, and the needle roller fitted in the recess is used by the compression mechanism. In the needle roller compression method of forming an inclined surface at the boundary outer peripheral portion of the end portion and the side portion of the needle roller by compressing in the axial direction,
An inclined surface that does not exceed 45 degrees with respect to the axial direction of the concave portion is provided at a boundary portion between the bottom surface portion and the side surface portion of the concave portion, and the needle roller fitted into the concave portion is axially compressed within the range of the inclined surface. A needle roller compression method. The needle roller compression method according to claim 3, wherein the inclined surface is a tapered surface inclined linearly from a side surface.

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