JPS6117614B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrodynamic pressure generating surface of a hydrodynamic thrust plate having a sloping dynamic pressure generating surface on a cylindrical end surface used as a fluid sliding bearing, or a hydrodynamic pressure generating surface when making such a thrust plate. This invention relates to a processing jig for creating a dynamic pressure generating surface on the cylindrical end surface of a master cam.

Figure 1 shows a type of thrust plate that generates dynamic pressure. That is, an inclined surface for generating dynamic pressure is provided on one end surface of the ring. Normally, when the thrust load is small, a simple annular parallel plate is used as the thrust plate for a bearing, but when the thrust load is large, there is a risk that the thrust plate and the surface facing it may seize. Therefore, the thrust plate is provided with a minute step or a stepped spiral surface for generating dynamic pressure as shown in FIG. 1 along the direction of rotation of the thrust plate.

Although it is easy to machine a minute step as described above, it is not easy to machine a minute spiral surface along the direction of rotation as shown in FIG. Conventionally, there have been two methods of machining such minute stepped spiral surfaces: manual finishing and grinding using a combination of a thread cutting lathe and a lace grinder, but neither method has been able to achieve high accuracy.

The present invention provides a jig that can be mounted and fixed on the table of a horizontal surface grinder or horizontal milling machine to easily and accurately create a hydrodynamic pressure generating surface with an inclined surface. This will be explained in detail below using embodiments shown in the drawings.

2 and 3 show embodiments of the present invention, 1
is a workpiece mount, and a reference plate 6 is fixed to one side wall, and a lower reference surface 101 that is in close contact with the table 7 and serves as the bottom of the workpiece mount is connected to the lower reference surface 101. The upper reference surface 102 has a predetermined inclination and is the upper plane of the workpiece mounting table, and is located above the upper reference surface 102.
and a lateral reference plane 103 that is a plane perpendicular to both the lower reference plane 101, as the inner side wall of the reference plate body 6.

Further, the groove is bored on the lower reference surface 101 side, the bottom surface of the groove is parallel to the upper reference surface 103, and both side surfaces of the groove are on the lateral reference surface 101 side.
03, and a groove bottom surface and an upper reference surface 10 along the longitudinal direction in the center of the groove.
It has an elongated hole 2 which is narrower than the groove width and is bored through the groove. Reference numeral 3 denotes a bolt inserted from below the long hole 2, and a cylindrical workpiece 5 with a bottom that is to form a dynamic pressure generating surface with an inclined surface on the opening side edge.
The workpiece is attached to the inclined upper reference surface 102 of the mounting table 1 by passing through a hole provided in the center of the bottom wall of the mounting table 1 and using the nut 4.
Fix it on top.

The reference body 6 is a member having a horizontal reference surface 103 as an inner side wall and protrudes from the upper reference surface 102, and 7 is a table of a horizontal surface grinder or a horizontal milling machine. The workpiece mount 1 is mounted and fixed on this table 7, for example, by magnetic attraction. 8 is a tool consisting of a grindstone or milling cutter that rotates around a horizontal axis.

Next, a method of processing a cylindrical workpiece 5 using the jig of the present invention will be explained. The left and right direction of the table of a horizontal surface grinder or horizontal milling machine that is a processing machine,
The jig is installed on the processing machine table 7 so that the direction perpendicular to the horizontal reference plane 103 of the workpiece mounting base 1 (the direction of arrow a in FIG. 2 is taken as the left-right direction) coincides with the direction. Next, the cylindrical workpiece 5 is fixed to the workpiece mount 1 with the bolt 3 and nut 4 with its outer cylindrical generatrix pressed against the lateral reference surface 103.
Here, the height of the plate 6 whose side wall is the horizontal reference plane 103 is sufficiently lower than the height of the cylindrical workpiece 5.
The tool 8 is made so as not to come into contact with the plate 6. Further, the table 7 is moved in the front-rear direction so that the center line in the width direction of the tool 8 and the center axis of the cylindrical workpiece 5 substantially coincide (the directions of arrows c and d in FIG. 2 are the front-rear direction of the table 7). ) and set.

The cylindrical workpiece 5 is fixed in this way, the tool 8 is cut into the cylindrical workpiece 5 to the required depth, and in this state, the processing machine table 7 is reciprocated in the direction of arrow a to cut the cylinder of the workpiece 5 in that direction. Create a flat surface parallel to the table surface within the end surface. Next, the nut 4 is loosened, and while pressing the workpiece 5 against the horizontal reference surface 103, the workpiece 5 is rotated on the mounting base 1 in the direction of the arrow b in FIG. 2 and moved in the direction of the arrow d. At that time, the workpiece 5
The distance that the outermost circumference of the tool 8 rolls on the horizontal reference plane 103 is
Make sure that the width is less than or equal to the width of the cutter, so that there are no uncut areas. At this moving position, the nut 4 is given up and the workpiece 5 is fixed to the mounting base 1. Due to the rotational movement of the workpiece 5 at this time, the center of the workpiece 5 and the center of the tool 8 in the width direction become misaligned, so move the table of the processing machine in the direction of arrow c to align the centers of the two. to correct. In this state, without changing the depth of cut of the tool 8, the width of the tool 8 is uniformly cut even in the portion where the tool 8 is reciprocated in the direction of the arrow a.

By repeating the above procedure until the depth of cut of the tool 8 becomes 0, one inclined surface is formed on the cylindrical end surface of the workpiece 5. If the width of the tool 8 and the pitch of the rotational feed are infinitely small, and the number of rotational feeds is infinite, then at any radial position, the angle between the circumferential direction and the bottom of the cylinder will be the same as the slanted surface of the mounting base and the processing machine table. It becomes a continuous slope equal to the angle formed by the surface.

In reality, in terms of working time and tool wear, tools 8
There is a limit to how small the width of the tool 8 can be made, and the tool 8 has a finite width. At this time, the inclination of the cylindrical end face is formed by a refractive surface if viewed minutely, but if the width of the tool 8 and the rotational feed pitch of the workpiece 5 are made small, it can be regarded as a sufficiently smooth surface for practical purposes. .

To form multiple sloped surfaces as shown in Figure 1, after processing one sloped surface as described above,
The machining start position of the cylindrical workpiece 5 may be moved by a rotation angle corresponding to one inclined surface without changing the machining start position on the mount 1. Of course, the bottomed cylinder with the hydrodynamic pressure generating shaped surface formed on the end face as described above can be used as a hydrodynamic thrust plate as it is, but it can also be used as a cylindrical hydrodynamic thrust plate by cutting off the bottom. You can also do that.

As described above, according to the jig of the present invention, it is possible to easily and accurately process a stepped spiral surface with a dynamic pressure generating shape onto which the inclination angle of the mounting base is transferred.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a dynamic pressure thrust plate, FIG. 2 is a plan view of an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof. 1... Workpiece mounting stand, 3, 4... Fixture, 10
3... Horizontal reference plane, 7... Table of processing machine.

Claims (1)

[Claims] 1. For machining a dynamic pressure generating shaped surface on the opening side cylindrical end surface of a bottomed cylindrical workpiece with a small hole in the center, which is used by being placed and fixed on the table surface of a horizontal surface grinder or horizontal milling machine. It is a jig,
It consists of a mounting base for attaching the bottomed cylindrical workpiece and a bolt nut for fixing the bottomed cylindrical workpiece to the mounting base, and the mounting base has a reference plate fixed to one side wall, a lower reference surface that is a flat surface that is in close contact with the table surface and serves as the bottom of the mount, and an upper reference surface that has a predetermined inclination with respect to the lower reference surface and serves as the upper plane of the mount; Further, the reference plate has a horizontal reference plane which is a plane above the upper reference plane and is perpendicular to both the upper reference plane and the lower reference plane as an inner side wall of the reference plate, and further includes a lower reference plane of the mounting base. a groove with a U-shaped cross section, the groove bottom being parallel to the upper reference plane, and both sides of the groove being parallel to the horizontal reference plane; an elongated hole having a width narrower than the groove width of the groove, which is bored through the groove bottom surface and the upper reference surface; Penetrating both the small hole and the elongated hole in the center of the bottomed cylindrical workpiece with the outer cylindrical generatrix of the bottomed cylindrical workpiece in contact with the horizontal reference plane; A dynamic pressure generating shaped surface machining jig, characterized in that the bottomed cylindrical workpiece can be fixed at any position in the longitudinal direction of the elongated hole with the bolt nut.