JPH0362529B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing cylindrical ceramic parts.

[Technical background of the invention and its problems]

For example, as shown in Figure 1, the outer diameter is 3 mm and the inner diameter is 3 mm.
In order to precisely process a small 0.125 mm cylindrical ceramic component 1 to within 1 μm of the roundness of the outer circumferential surface and its inner circumferential surface, and the coaxiality of the outer circumferential surface and the inner circumferential surface, for example, the conventional method is as follows. Holes are drilled using metal processing techniques such as drilling, electrical discharge machining, and electrolytic machining, and the outer diameter is finished by grinding. In this case, two processing methods are used: drilling and finishing the outer diameter, so usually the outer peripheral surface is processed first, and then the processed outer peripheral surface is held in a chuck and used as a processing reference to perform drilling. In this case, the roundness of the inner circumferential surface of the hole and the coaxiality between the outer circumferential surface and the inner circumferential surface are determined by the way the outer circumferential surface is gripped by the chuck and the circularity of the outer circumferential surface. However, if a chuck grips a ceramic part in a semi-fired state, the gripping force of the chuck deforms and destroys the ceramic part, making highly accurate centering impossible. Further, if the outer circumferential surface of the ceramic part is machined after the main firing, the ceramic part is extremely hard, so it not only becomes extremely difficult to machine it, but also reduces the machining accuracy. Therefore, in the past, it has been difficult to manufacture cylindrical ceramic parts with high precision even when the ceramic parts are in either a semi-fired or fully fired state.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for manufacturing ceramic parts that can manufacture cylindrical ceramic parts with high precision.

[Summary of the invention]

One end of the workpiece made of pressure-formed or semi-fired cylindrical ceramic is held in a cylindrical jig, the jig is gripped by a chuck, the outer circumferential surface is finished and holes are machined, and then the final firing is performed. It is something that makes you

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on examples with reference to the drawings.

First, a cylindrical workpiece 2 is obtained by pressure-molding ceramic powder. A tapered portion 2 a is formed at one end of the workpiece 2 . This workpiece 2 is formed to have a large length in consideration of the chucking allowance and an outer diameter taking into consideration the shrinkage allowance and processing allowance during the main firing. Next, this pressure-formed workpiece 2 is semi-baked at a low temperature of 1000°C or less.
However, this semi-baking step may be omitted. Thus, the tapered part 2a of the workpiece 2 is fitted into the tapered hole 3a of the cylindrical jig 3 provided with the tapered hole 3a into which the tapered part 2a of the workpiece 2 is fitted, and at the same time, for example, an adhesive is applied. For example, the two are integrally joined (see Fig. 2). Tapered part 3 of this jig 3
The inner circumferential surface of a is processed so that its roundness is extremely accurate. Next, the chuck 4 is made to grip the jig 3 into which the workpiece 2 is fitted (the third
(see figure). Then, the outer circumferential surface 5 of the workpiece 2 is processed by cutting or grinding, and a hole 6 is made by drilling while the workpiece 2 is held in the same chuck 4 (see FIG. 4). At this time, an allowance for shrinkage and an allowance for finishing (for example, wrapping) due to the main firing are left for both the outer diameter and the inner diameter.
Remove the next jig 3 from the workpiece 2, and
Only the final firing is performed. After the main firing, the tapered portion 2a is again bonded to the jig 3 using an adhesive or the like using the tapered hole 3a as a reference. Because of the taper, the axes of the jig 3 and the workpiece 2 are reliably aligned, and the accuracy of the pre-processing performed after molding or during pre-baking can be reproduced. Then, the jig 3 is turned on to finish grinding the outer periphery and wrapping the hole. Next, the workpiece 2 is cut to a required length using a cutting whetstone, for example, along line A-A' in FIG.

As described above, in the method for manufacturing ceramic parts of this embodiment, the outer diameter machining and hole machining are continuously performed using the jig 3 while being gripped by the same chuck. It can be processed in a soft state after pressure forming or semi-baking, allowing high precision processing. For example, outer diameter 3mm, length 5mm,
When applying the method of this example to a ceramic part with a hole diameter of 0.125 mm, the roundness of the outer and inner circumferential surfaces is
It was possible to process with an accuracy of 1 μm, a coaxiality of 1 μm between the outer circumferential surface and the inner circumferential surface, and a surface roughness of 2 μm R _nax .

In the above example, the processing is performed twice after the main firing, but if the processing after the main firing can be omitted, the cutting process of the workpiece 2 can be performed before the main firing. It's good to wear. Moreover, in this case, the hole of the jig 3 may be a hole of equal diameter instead of the tapered hole 3a. It is preferable to use press fitting or shrink fitting to fasten the workpiece 2 into this equal diameter hole.

〔Effect of the invention〕

In the method for manufacturing ceramic parts of the present invention, outer diameter machining and hole machining are performed using the same chuck while a workpiece made of ceramic is in a pressure-formed state or in a pre-sintered state, so that machining is facilitated, and Machining accuracy is significantly improved.

[Brief explanation of drawings]

Fig. 1 is an external view of a ceramic part, Fig. 2 is a sectional view of a main part showing how a workpiece is held by a jig in an embodiment of the present invention, and Fig. 3 is also a diagram showing how a workpiece is held by a chuck. FIG. 4 is a diagram showing the outer diameter machining and hole machining of the workpiece. 1: ceramic parts, 2: workpiece, 3: jig, 4: chuck.

Claims (1)

[Claims] 1. In a ceramic parts manufacturing method for manufacturing cylindrical ceramic parts, there is a step of holding one end of a cylindrical pressure-formed or semi-fired workpiece in a cylindrical jig, and a step of holding the above jig in a chuck. Processing the outer peripheral surface of the workpiece by gripping it and drilling a hole coaxially with the outer peripheral surface while the same chuck grips the workpiece, and firing the workpiece that has been subjected to the outer peripheral surface processing and the hole drilling. A method for manufacturing ceramic parts, comprising the steps of: