JPH06297226A - Groove forming tool for bearing having groove - Google Patents

Abstract

PURPOSE:To form a groove cross-sectional shape in a desired shape such as a rectangular cross section without creating an upward protrusion on both sides of a groove as well as to arrange a cutting protrusive part easily by the desired number with excellent dimensional accuracy in a tool including a tool to form a groove in a small diameter bearing hole or a shaft body. CONSTITUTION:An upper part is formed as a large diameter grip part 12 to be held, and a lower part is formed as an approximately cylindrical small diameter insertion part 14 to be inserted in a bearing hole 34. A tapering part 16 is formed in a truncated cone shape to smooth insertion. The first guide part 18 and the second guide part 22 are inserted in the bearing hole 34, and guides so that the axes of the bearing hole 34 and a tool 10 coincide with each other. A cutting protrusive part 24 in the same number with the number of grooves to be arranged in a bearing 32 is arranged outward protrusively in the diameter direction with every central angle of 45 degrees on the circumference situated in the upper, lower and intermediate parts of a cutting protrusive part setting part 20. A cross-sectional shape of the cutting protrusive part 24 is formed in a rhombus where an angle of respective sides to the axis is 55 degrees, and the cutting edges 26 and 27 are arranged on two sides on the lower side of the outside end in the diameter direction of the cutting protrusive part 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for forming a groove in a slide bearing which is lubricated by a fluid.

[0002]

2. Description of the Related Art As a means for forming a groove for generating a dynamic pressure in a lubricating fluid in a sliding bearing in which a lubricating action is performed by a fluid, a conventional method is disclosed in, for example, Japanese Unexamined Patent Publication No. 54-845155. There are known ones that use a steel ball and a cage as shown in Fig. 1 and one that pushes a steel ball into a bearing hole for forming a tool that is embedded in a shaft in a semi-projected state.

However, in these means, since the groove is formed by the plastic deformation generated on the peripheral surface portion of the bearing by the steel ball, as shown in FIG. 6, a groove sectional shape other than the bow shape cannot be obtained. , Due to plastic deformation, on both sides of the groove a,
The bulge b, which is not desirable for the function of the bearing, is generated.

Further, in the case where a steel ball is embedded in a shaft or the like in a semi-protruding state, it is relatively difficult to improve the dimensional accuracy in the radial direction, and a steel ball is used in a tool for forming a groove in a bearing hole of a small diameter. Since the diameter of the shaft or the like to be embedded becomes small, it becomes difficult to embed the steel ball itself, so that there is a limit to the inner diameter of the bearing hole in which the groove can be provided.

The present invention has been made in view of the above problems existing in the prior art, and the object thereof is to prevent swelling on both sides of the groove.
The cross-sectional shape of the groove can be formed into a desired suitable shape such as a rectangular cross-section, and a desired number of cutting protrusions including a tool for forming a groove in a small-diameter bearing hole or shaft can be formed with good quality. An object of the present invention is to provide a groove forming tool for a grooved bearing that can be easily provided with dimensional accuracy.

[Means for Solving the Problems]

In order to achieve the above object, the groove forming tool for a grooved bearing of the present invention is inserted into a bearing hole and relatively moved in the axial direction and the circumferential direction with respect to the bearing hole. A tool for forming a groove in the inner peripheral part of the bearing, the guide part for aligning the axis by being inserted into the bearing hole is provided in the outer peripheral part, and the same number as the number of grooves to be provided in the bearing or The cutting projections of a fraction of the whole number are projected outward in the radial direction, and a cutting edge is provided at least in a portion of the outer peripheral portion of the radial outer end of the cutting projection that faces the direction in which the groove should be cut. I have it.

Further, another groove forming tool for bearings according to the present invention is fitted onto the shaft body and is moved relative to the shaft body in the axial direction and the circumferential direction so that the outer peripheral portion of the shaft body is A tool for forming a groove, which is provided on the inner peripheral portion with a guide portion for aligning the axis by being externally fitted to the shaft body, and the same number as the number of grooves to be provided on the shaft body or an integer thereof. Of 1
The number of the cutting projections is projected inward in the radial direction, and the cutting edge has a cutting edge at least in the outer peripheral portion of the radial inner end of the cutting projection facing the direction in which the groove is to be cut.

[0008]

When the tool of claim 1 is inserted into the bearing hole, the guide hole provided on the outer peripheral portion of the tool causes the axis of the bearing hole and the axis of the tool to coincide with each other.

Since the cutting projection provided on the outside of the tool in the radial direction has a cutting edge at least in a portion of the outer peripheral portion of the radial outer end thereof facing the direction in which the groove should be cut, the bearing hole is formed. When the blades are moved relative to each other in the axial direction and the circumferential direction, a groove can be formed in the inner peripheral portion of the bearing hole by cutting with the cutting edge. If the number of cutting protrusions is an integer fraction of the number of grooves to be provided in the bearing, the desired number of grooves can be obtained by changing the angle and repeating the cutting process by that number.

Since the groove in this case is formed by cutting with a cutting edge, it is possible to form the groove into a desired shape such as a rectangular cross section without causing swelling on both sides of the groove.

The cutting projection can be provided by cutting out, fitting and fixing the bar member for cutting projection, or the like.

When the tool of claim 2 is externally fitted to the shaft body, the axis of the shaft body and the tool are aligned with each other by the guide portion provided on the inner peripheral portion of the tool.

Since the cutting projection provided radially inward of the tool has a cutting edge at least in a portion of the outer peripheral portion of the radial inner end facing the direction in which the groove should be cut, the shaft body When the blades are moved relative to each other in the axial direction and the circumferential direction, a groove can be formed in the outer peripheral portion of the shaft body by cutting with the cutting edge. If the number of cutting protrusions is an integer fraction of the number of grooves to be provided in the bearing, the desired number of grooves can be obtained by changing the angle and repeating the cutting process by that number.

Since the groove in this case is formed by cutting with a cutting edge, it is possible to form the groove into a desired shape such as a rectangular cross section without causing swelling on both sides of the groove.

The cutting protrusion can be provided by cutting out, fitting and fixing the rod member for cutting protrusion, or the like.

[0016]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a main portion of a groove forming tool for a grooved bearing as one embodiment of the present invention.

The tool 10 is made of cemented carbide, and has a large-diameter handle portion 12 held by a machine tool or the like at the time of groove forming, and a small-diameter substantially small portion inserted in the bearing hole at the lower portion. It is a cylindrical insertion portion 14.

The insertion portion 14 extends upward from the lower end of the insertion portion 14, the tapered portion 16, the first guide portion 18, the cutting protrusion setting portion 2
0 and the second guide portion 22.

The tapered portion 16 is the insertion portion 14 for the bearing hole.
In order to facilitate the insertion of the above, it is formed in a truncated cone shape whose diameter is reduced downward.

The first guide portion 18 and the second guide portion 22
Is inserted into the bearing hole, so that the bearing hole and the tool 1
It guides the axes of 0 to coincide with each other, and has a constant outer diameter substantially equal to (slightly slightly smaller than) the inner diameter of the bearing hole.

For each constant center angle (45 degrees in this embodiment) on the circumference located in the upper and lower middle of the cutting protrusion setting portion 20, the same number of cuttings as the number of grooves (8 in this embodiment) to be provided in the bearing is cut. The protrusion 24 is provided so as to protrude radially outward. The outer diameter of the remaining portion of the cutting protrusion setting portion 20 is slightly smaller than the outer diameters of the first guide portion 18 and the second guide portion 22. Therefore, the finishing of the remaining outer peripheral surface does not need to be precise.

The cross-sectional shape of the cutting projection 24 is a rhombus in which the angle of each side with respect to the axis is 55 degrees, and the cutting projection 24 is cut on the lower two sides at the radial outer end thereof. Blades 26 and 27 are provided.

In such a cutting protrusion 24, the outer diameter of the cutting protrusion setting portion 20 is made larger than the outer diameters of the first guide portion 18 and the second guide portion 22 in advance, and the two-dot chain line in FIG. As shown by the cutting path 28, it can be relatively easily provided by cutting with the rhombus portion left at the same angle as the groove inclination with respect to the axis, that is, 55 degrees in the embodiment. If the cutting protrusion 24 is provided by cutting in this way,
It is possible to relatively easily provide the desired number of cutting projections 24 with good dimensional accuracy, including the tool 10 for forming the small-diameter bearing hole.

As the material of the tool 10, at least the cutting edge portion of the cutting projection 24 needs to be formed of a high hardness material. Specifically, in addition to cemented carbide, ceramics, cermet, etc. Can be appropriately adopted.

FIG. 2 is a schematic sectional view of a main part of a bearing 32 in which the herringbone groove 30 is formed by using the tool 10. The portion of the bearing hole 34 where the groove is to be formed, that is, the inner diameter of the groove forming portion 36 is equal to the first guide portion 18
And substantially equal to the outer diameter of the second guide portion 22 and slightly smaller than the inner diameters of other portions.

The herringbone groove 30 can be formed in the bearing 32 using this tool 10, for example, as follows.

First, the handle 12 of the tool 10 is held by a machine tool, and the bearing 32 is also held by another device. Then, while aligning the axes of the tool 10 and the bearing 32 with each other, the downward feed and the counterclockwise rotation (when viewed from above) are synchronized so that the tool 10 draws a spiral at a groove forming angle (angle of 55 degrees) with respect to the axis. Then, the insertion portion 14 is inserted into the bearing hole 34 in order from the tapered portion 16.

When the first guide portion 18 is inserted into the groove forming portion 36, the axis lines of the bearing hole 34 and the tool 10 are aligned with each other. When the cutting protrusion 24 reaches the groove forming portion 36, the lower right cutting edge 27 of each cutting protrusion 24 cuts the groove in a counterclockwise spiral shape downward. The cutting protrusion 24 has a groove forming portion 36.
When it reaches the upper and lower center position of the tool 10, the rotation direction of the tool 10 is reversed, and the tool 10 feeds downward and rotates clockwise so that the tool 10 draws a spiral at the groove forming angle (angle of 55 degrees) with respect to the axis (looking down from above). In this case, the lower left cutting edge 26 of each cutting projection 24 cuts the groove in a clockwise spiral shape downward. At this time, the second guide portion 22 is inserted into the groove forming portion 36, and the alignment between the bearing hole 34 and the axis of the tool 10 is maintained. Since the cutting projection 24 is used for cutting, it is possible to form the cross-sectional shape of the groove 30 into a rectangular cross-section having a dynamic pressure generation efficiency higher than that of the arcuate shape without causing bulging on both sides of the groove 30. After the cutting protrusion 24 reaches below the groove forming portion 36, if the tool 10 is reversely fed and reversely rotated to move the same path in the reverse direction, the tool 10 is detached from the bearing hole 34.

In this way, a herringbone groove 30 consisting of eight grooves each having a central angle of 45 degrees is formed by drawing a spiral at a groove forming angle (angle of 55 degrees) with respect to the axis and reversing at the vertical center position. . Of course, the feed and rotation is done with the tool 10
And the bearing 32 may be performed.

In the above embodiment, eight cutting protrusions 2 are used.
Although 8 herringbone grooves are formed using 4,
An arbitrary number of grooves can be formed by providing the number of cutting protrusions 24 that is the same as the number of grooves to be formed or is an integer. If cutting edges are provided on the four sides at the radially outer end of the cutting projection 24, the tool 10 is fed downward to cut the groove as described above, and then the tool 10 is rotated by 22.5 degrees. If the tool 10 is fed in the opposite direction and rotated in the opposite direction,
When returning the tool 10 to the upper side, it is possible to further cut eight grooves by the upper two cutting edges to obtain 16 grooves at every 22.5 degree center angle (however, in this case, Cutting protrusion 2
It goes without saying that it is necessary to make the size of 4 appropriate. ).

On the other hand, in the case of cutting the groove by only one (lower) feed as described above, the cross-sectional shape of the cutting protrusion is not always rhombic if it has lower right and lower left cutting edges. It doesn't need to. If a spiral groove in only one direction (for example, a counterclockwise spiral toward the bottom) is provided, the cutting edge has one position facing the direction in which the groove should be cut (for example, the cutting protrusion). (Only the cutting edge 27 at 24) may be used.

FIG. 3 is a front view of a main portion of a groove forming tool for a grooved bearing as another embodiment of the present invention.

In this tool 40, the cross-sectional shape of the cutting projection 24 in the tool 10 of the above-described embodiment is changed to a circular shape, and a cutting edge is provided on the entire circumference at the radially outer end of the cutting projection 42. . With this configuration, the direction of the groove to be cut is not limited, and there are few restrictions in use. Also, in the sense that the cross-sectional shape is close to a circle and directionality is eliminated as much as possible,
The cross-sectional shape of the cutting projection may be a polygon such as a regular octagon, and cutting edges may be provided on all sides at the radially outer end of the cutting projection.

FIG. 4 is a fragmentary plan view of a groove forming tool for a grooved bearing as still another embodiment of the present invention, and FIG. 5 is a shaft body 62 in which a herringbone groove 60 is formed by using this tool 50. It is a typical front view about the principal part of. A portion of the shaft body 62 where the groove is to be formed, that is, an outer diameter of the groove forming portion 64 is slightly larger than outer diameters of other portions.

This tool 50 is arranged in a constant circumferential portion of a cylindrical body 52 having a constant inner diameter substantially equal to the outer diameter of the groove forming portion 64 (strictly speaking, slightly larger), at radial intervals of 45 degrees. By providing the fitting holes 54 and fitting and fixing the cylindrical cutting members 56 (bar-shaped members for cutting projections) into the fitting holes 54, the cutting members 56 protruding inward of the cylindrical body 52.
The inner end of each of the cutting protrusions 58 is used as a cutting protrusion 58.
A cutting edge is provided on the entire circumference at the radially inner end of 8.
The inner peripheral portion of the cylindrical body 52 other than the annular portion provided with the cutting member 56 is a guide portion, and the guide portion is externally fitted to the groove forming portion 64 of the shaft body 62, whereby the shaft body 60 and the tool 50 are The axes match. Since the cutting protrusions 58 can be provided by fitting and fixing the columnar cutting member 56 or the like, a desired number of cutting protrusions including a tool for forming a groove on a shaft body having a small diameter can be provided with good dimensions. It can be provided relatively easily with accuracy.

The tool 50 is held by a machine tool and the shaft 6
0 is also held by another device so that the axes of the tool 50 and the shaft body 60 are aligned with each other, and the tool 50 is rotated clockwise so as to draw a spiral at a groove forming angle with respect to the axis (when viewed from above), while being rotated downward. By feeding and reversing the rotation direction at the vertical center position of the groove forming portion 64, the herringbone groove 60 as shown in FIG. 5 is formed.

The vertical positional relationship in the above description of the embodiments is merely for convenience of explanation based on the drawings, and does not limit the actual use state or the like.

[0038]

According to the groove forming tool for grooved bearings of the present invention,
Since the groove is formed by cutting with a cutting edge, unlike the conventional case where the groove is formed by plastic deformation using a semi-protruding steel ball, the cross section of the groove does not rise up on both sides of the groove. The shape can be formed into a desired suitable shape such as a rectangular cross section.

Since the cutting protrusion can be provided by cutting out, fitting and fixing the rod member for cutting protrusion, etc., it is possible to improve the radial dimensional accuracy when the conventional steel ball is embedded in a semi-projected state. And the difficulty of embedding a steel ball in a small diameter tool for forming a groove in a small diameter bearing hole are avoided. Therefore, a desired number of cutting protrusions including a small-diameter bearing hole and a tool for forming a groove in the shaft body can be relatively easily provided with good dimensional accuracy.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a groove forming tool for a grooved bearing.

FIG. 2 is a schematic cross-sectional view of a main part of a bearing having a herringbone groove formed therein.

FIG. 3 is a front view of a main part of a groove forming tool for a grooved bearing according to another embodiment.

FIG. 4 is a fragmentary plan view of a groove forming tool for a grooved bearing as still another embodiment.

FIG. 5 is a schematic front view of a main part of a shaft body having a herringbone groove formed therein.

FIG. 6 is a cross-sectional view of a main portion of a conventional groove portion.

[Explanation of sign]

 12 Handle part 34 Bearing hole 14 Insertion part 18 First guide part 22 Second guide part 34 Bearing hole 10 Tool 20 Cutting protrusion setting part 32 Bearing 24 Cutting protrusion 26 Cutting edge 27 Cutting edge

Claims (2)

[Claims] 1. A tool for forming a groove in an inner peripheral portion of a bearing hole by inserting the bearing hole into the bearing hole and moving the bearing hole relative to the bearing hole in an axial direction and a circumferential direction. A guide part for aligning the axes by being inserted into the inside is provided on the outer peripheral part, and the same number of cutting protrusions as the number of grooves to be provided on the bearing or a fraction of the integer thereof is projected outward in the radial direction. A groove forming tool for a grooved bearing, which is provided and has a cutting edge at least in a portion of an outer peripheral portion of a radial outer end of the cutting protrusion which faces a direction in which the groove is to be cut. 2. A tool for forming a groove on the outer peripheral portion of a shaft body by fitting the shaft body externally and moving the shaft body relative to the shaft body in the axial direction and the circumferential direction. A guide portion is provided on the inner peripheral portion for matching the axes by being fitted externally, and the number of cutting protrusions to be provided on the shaft body is equal to or a fraction of an integer thereof, and the cutting protrusions are radially inward. A groove forming tool for a grooved bearing, characterized in that it has a cutting edge at least in a portion of an outer peripheral portion of a radially inner end of the cutting protrusion that is opposed to a direction in which the groove is to be cut.