JPS6328744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a surface grinder to grind the outer periphery of a pipe-shaped workpiece using a small diameter hole as a reference, thereby performing concentric machining of the hole and outer periphery of the workpiece. The present invention relates to a concentric processing machine for processing small-diameter pipes, etc.

Generally, when concentrically machining a pipe-shaped workpiece, as shown in a side view in FIG. 1, the eccentric portion 3 at the outer circumference is removed with reference to the hole 2 of the workpiece 1.

Examples of conventional concentric processing machines are shown in Figures 2, 3, and 4.
This will be explained using the conceptual diagram shown in the figure.

Figure 2 shows a hole-based concentric processing machine using a cylindrical grinder. A pair of centers 5 are supported in a hole 2 of a pipe-shaped workpiece 1 at a portion 4 to perform center milling, and the outer periphery of the workpiece 1 is cylindrically ground with a grindstone 6. This device has the disadvantage that it cannot be applied to concentric machining of workpieces 1 with small diameter holes because the center 5 cannot support workpieces 1 with hole diameters of 1 mm or less.

FIG. 3 is an example of a concentric turning machine. Hold the pipe-shaped workpiece 1 on the work head 8 with the collector chuck 7, and observe the hole 2 enlarged on the monitor TV 10 through the ITV camera 9 from the A side. 2. Operate the position adjustment mechanism 12 of. Thereafter, the main shaft 13 is rotated, and the outer circumferential surface of the workpiece 1 is cut using two cutting tools 14 attached to the main shaft 13 to perform concentric machining. However, with this machine,
Since Hole 2 is observed under magnification, concentric machining is possible even with a pipe with a small diameter hole, but since the cutting is done with the cutting tool 14, the roughness of the machined surface is as high as 2 μm Rmax on average, and the work head is 8 and then proceed to the cutting process, which has the disadvantage of poor production efficiency because it is always necessary to repeat the position adjustment and cutting process.

FIG. 4 is an example of a concentric processing machine using a cylindrical grinder that can perform concentric processing even on pipes with small diameter holes. The pipe-shaped workpiece 1 is held by a four-jaw chuck 15 that can be held eccentrically with respect to the spindle rotation center 11, and the pipe-shaped workpiece 1 is held on a monitor TV via an ITV camera 12.
While observing the hole 2 under magnification in step 10, after aligning the rotation center 11 of the spindle with the center of the hole 2,
In this method, the outer periphery of the pipe-shaped workpiece 1 is cylindrically ground with a grindstone 6 in a cantilevered manner, and the hole 2 and the outer periphery of the pipe-shaped workpiece 1 are machined concentrically. In this device as well, the production efficiency is poor because the workpiece 1 is attached to the processing machine and then position adjustment and grinding are performed.

As mentioned above, with conventional concentric machining machines, concentric machining is not possible when the hole in a pipe-shaped workpiece is small, or even if concentric machining is possible, the production efficiency is poor. There were flaws.

Therefore, the present invention enables concentric machining with high production efficiency even when the diameter of the hole in a pipe-shaped workpiece is 1 mm or less, and enables highly accurate machining using a general-purpose surface grinder as a machining machine. The purpose of the present invention is to provide a concentric processing machine that enables concentric processing.

To this end, in the present invention, a rotary holding shaft having a workpiece holding part at the end that can adjust the axis with respect to the workpiece is placed on a bearing part having a V-shaped groove and rotated. , With such a configuration, it is possible to process a workpiece having a microhole, and further,
By removing only the rotation holding shaft, it is possible to perform the grinding process and the process of adjusting the axis of the workpiece independently, resulting in high production efficiency.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 5 is an overall configuration diagram of an embodiment of the present invention. Four-point support bearing 31 integrated with base 30
is placed on the table 33 of the surface grinder so as to be parallel to the rotation axis of the grindstone 32.

A pipe-shaped workpiece 1 having a small diameter hole 2 held by a pair of V-blocks 34 is attached to an adjusting screw 35.
Then, the position of the V block 34 is adjusted on the end face of the shaft 36 (rotation holding shaft) so that the center of rotation of the shaft 36 coincides with the center of its own hole, and is fixed with a screw 37. This shaft 36 is attached to the aforementioned four-point support bearing 31 via a belt 38 and a pulley 39, and is rotated by a motor 40 in the direction of the arrow. Here, while rotating the shaft 36,
When grinding the outer periphery of the workpiece 1 by cutting from above in the radial direction of the workpiece 1 with the grindstone 32, the grinding of the outer periphery progresses from the maximum eccentricity of the workpiece 1. The deflection portion 3 shown in FIG. 1 is removed, and the hole 2 of the workpiece 1 and the outer periphery become concentric.

FIG. 6a is a structural diagram of the four-point support bearing 31, and FIG. 6b is a side view taken from direction A in FIG. 6a.

In the four-point support bearing 31, the pressure receiving surface 41 has a structure of two V-blocks 42. Since the shaft 36 and the four-point support bearing 31 are in complete line contact at four locations, the theoretical shaft runout is only due to the machining accuracy of the shaft 36, and rotation with very little runout is possible. Also, the shaft 36
Since it is pressed against the pressure receiving surface 41 by a belt or the like, it can be freely removed from the bearing 31 and attached, unlike when using a rolling bearing or the like.

The four-point support bearing 31 is made of a highly wear-resistant material such as cemented carbide, hardened steel, ruby, or diamond. In addition, the four-point support bearing 31 does not have to be an integral structure as shown in FIGS. 6a and 6b, but only needs to have a two-V block configuration as a whole, so the tip has a high wear resistance as shown in FIG. 7a. It is also conceivable that the shaft 36 is supported by a screw 43 made of a durable material arranged at 90 degrees in the holder 44, or that only the pressure receiving portion 45 is made of a highly wear-resistant material as shown in FIG. 7b.

FIG. 8 shows the structure for holding the workpiece.

The workpiece 1 is sandwiched between a pair of V-blocks 34, and by tightening the screws 46, the V-blocks 34 are brought close to each other and fixed. In this case, since the V groove is machined perpendicularly to the bottom surface B of the V block, the workpiece 1 is held perpendicularly to the bottom surface B of the V block. Numeral 47 is a hole for fixing to the shaft 36 in FIG. 5, and a male screw (not shown) is inserted into this hole 47 and tightened to a female screw formed on the shaft 36 side.

In this embodiment, a pair of V-blocks are used to hold the workpiece, but a precision collect chuck may also be used.

FIG. 9 shows a structure for aligning the center of the small diameter hole of the workpiece 1 with the rotation center of the shaft 36.

The shaft 36 has holes drilled on the side C on which the V block is fixed, and screws 35 are arranged at four equally spaced positions around the circumference of the bored portion. Insert the workpiece 1 integrated with the V block 34 shown in FIG. 8 into this drilled area as shown in FIG. 10, loosely tighten the screw 37, and rotate the shaft 36.
The hole 2 of the workpiece 1 is enlarged and observed on the monitor TV 49 via the ITV camera 48, the screw 35 is moved so that there is no deflection in the hole, and the V block 34 is moved to align the center of the hole of the workpiece 1 and the axis. 36 are aligned, and then the V block 34 is fixed to the shaft 36 with a screw 37.

In this embodiment, since the shaft 36 is rotated using the four-point support bearing 31, not only the outer circumference roundness and surface roughness after grinding are good, but also the fifth
In the figure, by removing the belt 38 from the pulley 39, the shaft 36 integrated with the workpiece 1 can be freely removed from the four-point support bearing 31.
Further, even if the shaft 36 is reattached, the state will be exactly as before, so that the center of rotation of the shaft 36 and the center of the hole 2 of the workpiece will not be misaligned due to replacement of the shaft 36. Therefore, if the work of aligning the center of rotation of the shaft 36 with the center of the hole 2 of the workpiece 1 is performed on separate bearings of the same type, the position adjustment work can be performed completely independently of the grinding work, and the grinding work can be performed completely independently of the grinding work. This can be done by simply mounting the shaft 36, on which the position of the workpiece 1 has already been adjusted, onto the four-point support bearing 31 fixed to the table 33 of the surface grinder. That is, since the position adjustment work of the shaft 36 and the workpiece 1 and the grinding work can be performed in parallel and separately, production efficiency is greatly improved compared to the conventional method in which both the work is repeated sequentially.

As explained above, according to the present invention, a rotation holding shaft having a workpiece holding part at the end that can adjust the axis with respect to the workpiece is inserted into a V-shaped groove of a bearing part having a V-shaped groove. Since the workpiece is placed on the machine, the workpiece is no longer held from both ends of the hole, and even workpieces with minute holes can be held sufficiently and grinding is possible. Because it is easy to attach and remove the rotary shaft to the bearing, it is possible to remove only the rotation holding shaft and adjust the axial center between the workpiece and the rotation holding shaft separately from the grinding operation. Since it can be done as a process, very high production efficiency can be obtained when grinding a large number of workpieces.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the principle of concentric processing, Figs. 2 to 4 are schematic configuration diagrams showing a conventional concentric processing machine, and Fig. 5 is a diagram showing the principle of concentric processing.
The figure is a schematic perspective view showing a concentric processing machine in one embodiment of the present invention, Figures 6a and b are structural perspective views and side views of the bearing part, and Figures 7a and b are another embodiment of the bearing part. The side view shown, FIGS. 8 and 9 are perspective views of essential parts showing the rotation holding shaft, and FIG. 10 is an explanatory view of the axial center adjustment work of the rotation holding shaft. 1... Workpiece, 2... Hole, 30... Base,
31...Four-point support bearing, 32...Whetstone, 33...
Table, 34... V block, 35... Adjustment screw, 36... Rotation holding shaft, 37... Screw, 38...
...Belt, 39...Pulley, 40...Motor, 4
1...Pressure receiving surface, 42...V block, 46...screw, 47...hole, 48...ITV camera, 49...
...Monitor TV.

Claims (1)

[Scope of Claims] 1. Two V-shaped blocks each having a V-shaped groove formed perpendicularly to the bottom surface for sandwiching a cylindrical workpiece having a small diameter hole approximately at the center; 2 Vs
A coupling means for integrating the V-shaped block with a workpiece held therebetween; a rotating holding shaft having a dish-shaped portion on its peripheral wall having a plurality of movable members on its end face; A bearing section on which the rotation holding shaft is removably placed, having means for coupling and fixing the bottom surface in contact with the bottom surface of the dish-shaped part, and a V-shaped receiving section that contacts the rotation holding shaft at four places. A concentric processing machine comprising: a drive section that rotates the rotation holding shaft; and a rotation grinding section that grinds the workpiece, the rotation shaft being arranged so that the rotation shaft is parallel to the rotation holding shaft. 2 Align the rotational center of the small diameter hole of the workpiece with the rotational center of the rotational support shaft by moving the circumferential wall of the dish-shaped portion of the rotational support shaft around the two integrated V blocks that sandwich the workpiece. Claim 1, characterized in that this is carried out by displacing a plurality of movable members provided on the workpiece and pressing the periphery of two integrated V blocks that hold the workpiece. concentric processing machine.