JPH1128662A - Working method for tubular ceramic molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the working accuracy and the working efficiency for a workpiece by providing a chuck mechanism in two places near both ends of a pair of tubular ceramic moldings, and continuously performing cutting and cylindrical surface working while the formed body is rotated on its axis. SOLUTION: The vicinities of both ends of a β-alumina tube molding 1 are aligned with the center of rotation of a spindle 8 of a machine tool 6 to index the average shaft center, and simultaneously chucked by chuck mechanism parts 7A, 7B to be grasped. At the time of cutting, both a grinding wheel spindle 12 and a molding 1 are respectively rotated, and the grinding wheel spindle 12 is moved in the direction right-angled to the central axis of rotation of the molding 1 to be cut by a cutting grinding wheel 10, thereby performing cutting. After the end of cutting, a grinding wheel 11 for cylindrical surface working and a part to be worked of the molding 1 are relatively aligned in the axial direction, and while the grinding wheel spindle 12 is moved in the direction parallel to the central axis of rotation of the workpiece, the molding 1 is cut to attain a designated outer diameter by the grinding wheel 11. Thus working can be performed by chucking one time so as to improve working efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a tubular ceramic molded article such as a .beta.-alumina tubular molded article used as a solid electrolyte of a sodium-sulfur battery. The present invention relates to a method for processing a squareness with respect to a central axis and a concentricity of an end outer diameter with respect to a central axis with high accuracy and high efficiency.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing the structure of a sodium-sulfur battery. A β-alumina tube molded body 1 used as a solid electrolyte of a sodium-sulfur battery is hermetically bonded to α-alumina 2 and inserted into a positive electrode tube 3 with a sulfur layer 4 interposed therebetween. And is fixed to the cathode tube 3.

In a sodium-sulfur battery, a safety tube 5 which is a metal tubular component is inserted into a β-alumina tube.
This safety tube 5 is similarly fixed via α-alumina 2. As described above, since the β-alumina tube molded body 1 has tubular parts on the inner and outer surfaces of the tube, the perpendicularity and the concentricity with respect to the central axis of the β-alumina tube molded body 1 are provided at the sealing bonding portion with the α-alumina 2. And outer diameter accuracy is required.

However, the β-alumina molded body changes its dimensions due to shrinkage during sintering, and the entire tube is bent.
For this reason, it is very difficult to adjust the centering and the inclination of the shaft when fixing the bent β-alumina pipe molded body to the machine tool. The bent β-alumina tube molded body is cut into a predetermined length, and the cut surface is cut at a right angle to the average axis of the β-alumina tube molded body. A cylindrical surface must be machined to fit the outer diameter and concentric with the average axis of the β-alumina tube.

[0005] In each of these processes, since the specifications and shapes of the grinding wheels as tools are different from each other, it is conceivable to perform the process with each machine tool.
Re-chucking the alumina tube compact each time causes a reduction in working efficiency. In addition, re-chucking also causes whirling and tilting of the shaft, thereby lowering the processing accuracy.

As for the cylindrical surface processing for processing the adhesive sealing portion, a method of simultaneously processing the entire outer diameter portion of a β-alumina tube molded body has been devised as disclosed in Japanese Patent Application Laid-Open No. 4-283061. However, no consideration is given to the cutting process and the perpendicularity of the cut surface. Further, in the above method, since it is necessary to process the outer diameter portion other than the hermetically bonded portion, there is a problem that the processing time is longer than the processing of only the outer diameter portion of the hermetically bonded portion.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to make the average axis of the bent tubular ceramic body coincide with the rotation center of the main shaft of the machine tool. It is an object of the present invention to provide a processing method for performing a plurality of processing steps without chucking and re-chucking, thereby improving the processing accuracy and processing efficiency of a workpiece.

[0008]

A β-alumina tube molded body which is a bent tubular ceramic molded body has a shape shown in FIG. 3, and the vicinity of both ends of the tubular ceramic molded body is set at the center of rotation of a main shaft of a machine tool. By making them coincide with each other, it is possible to reduce the deviation amount of the rotation center between the actual shaft of the tubular ceramic molded body and the main shaft. Therefore, the present invention can be realized by providing two chuck mechanisms in which the center of rotation of the main shaft of the machine tool and the center of the chuck coincide with each other at positions near both ends of the tubular ceramic molded body.

[0009] From the cut surface side of the tubular ceramic molded body which is the workpiece to the chuck direction, a cutting grindstone used for cutting and a grindstone used for cylindrical surface processing are fixed to the same grindstone shaft in this order. At this time, the cutting grindstone has an outer diameter larger than the cylindrical surface grindstone by a radius required for cutting. With the above configuration, cutting and cylindrical surface processing can be performed continuously.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a processing apparatus according to one embodiment of the present invention. Here, a diagram of processing a β-alumina tube molded body as a tubular ceramic molded body of a workpiece is shown.
In FIG. 1, a machine tool 6 is provided with chuck mechanisms 7A and 7B for gripping a β-alumina tube formed body 1, which is a workpiece, and a main shaft 8 for rotating them. The chuck mechanism 7B has a predetermined repetition chuck accuracy, is fixed to the main shaft 8, and is assembled and adjusted so that the center of the chuck coincides with the rotation center of the main shaft 8.

The chuck mechanism 7B rotates together with the rotation of the main shaft 8, and transmits a rotational force to the β-alumina tube molded body 1 held. Similarly, the chuck mechanism 7A also has a predetermined repetition chuck accuracy, and its chuck center is assembled and adjusted so as to coincide with the rotation center axis of the main shaft 8,
The β-alumina tube molding 1 is fixed to the machine tool 6 so as to be rotatably gripped by the rotational force of the main shaft 8 transmitted via the chuck mechanism 7B and the β-alumina tube molding 1. These chuck mechanisms 7A and 7B are provided on the machine tool 6 at a predetermined interval, and the vicinity of both ends of the β-alumina tube molded body 1 bent as described above is made to coincide with the rotation center of the main shaft 8 of the machine tool 6. Thereby, the deviation amount between the axis of the β-alumina tube molded body 1 and the rotation center of the main shaft 8 can be reduced.

The machine tool 6 has an XY table 9 which can be positioned at any position in the XY directions. A grinding wheel shaft 12 for rotating the cutting wheel 10 and the grinding wheel 11 for cylindrical surface processing is fixed to the XY table 9. These grindstones have an outer diameter of the grindstones, a thickness of the grindstones, a mounting interval between the grindstones so that one grindstone does not inadvertently come into contact with the β-alumina tube molding 1 when one grindstone is used for processing. Is determined. By moving the XY table 9, the relative position between the β-alumina tube formed body 1 as the workpiece and the cutting grindstone 10 or the grindstone 11 for cylindrical surface processing as the tool is changed, and the cut amount and the feed rate are controlled. I do. A method for cutting the β-alumina pipe molded body 1 as a workpiece and processing the outer diameter of a cylindrical surface in this configuration will be described.

First, with the chuck mechanisms 7A and 7B released, the β-alumina tube molded body 1 is put into them, and the chuck mechanisms 7A and 7B are simultaneously chucked to thereby form the β-alumina tube molded body 1. Hold.

The operation of the machine tool 6 during machining will be described in detail with reference to FIGS. FIGS. 4 and 5 are plan views of the relative positions of the β-alumina tube formed body 1, the cutting grindstone 10 attached to the grindstone shaft 12, and the grindstone 11 for cylindrical surface processing during processing, as viewed from above. FIG. 4 shows the relative positions of the grindstone shaft 12 and the β-alumina tube molded body 1 during the cutting process. These two members are respectively rotated to grind the grinding wheel shaft 12 so as to give a relative cut.
The cutting is performed by moving in the direction of arrow 13 perpendicular to the rotation center axis of.

After the cutting is completed, the movement in the direction of arrow 13 is stopped before the grinding wheel 11 for cylindrical surface processing comes into contact with the β-alumina tube molded body 1, and then the grinding wheel 11 for cylindrical surface processing and the β-alumina tube molding are stopped. In order to perform relative axial positioning of a portion to be processed of the body 1, the grinding wheel shaft 12 is moved in the direction of an arrow 14 parallel to the rotation center axis of the workpiece.

FIG. 5 shows the operation at the time of machining the cylindrical surface. In order to cut the grinding wheel 11 for cylindrical surface processing into the β-alumina tube molded body 1 until it reaches a predetermined outer diameter, the grinding wheel 11 is moved in the direction of an arrow 15 perpendicular to the rotation center axis of the β-alumina tube molded body 1,
Subsequently, the grindstone shaft 12 is moved in the direction of arrow 16 parallel to the rotation center axis of the workpiece to improve the surface roughness. The machining is completed as described above, the chuck mechanisms 7A and 7B are released from the chuck, and the β-alumina tube molded body 1 is removed from the machine tool.

Next, an example of actual processing will be described. For the chuck mechanisms 7A and 7B, a three-jaw air chuck having a repetition chucking accuracy of 30 μm is used, and the deviation between the center of the chuck and the rotation center of the spindle 8 is set to 50 μm.
m.

Further, a β-alumina molded tube was used as a workpiece. This β-alumina pipe molded body has a total length after cutting of 600 mm and an outer diameter of 64 mm, and has a maximum bending of about 0.5% of the total length. When cutting and cylindrical surface processing were performed using two conventional processing machines, a processing time of 85 minutes was required, the concentricity of the cylindrical surface with respect to the central axis of the β-alumina tube molded body 1 was 72 μm, and the The angle was 53 μm. On the other hand, by using the present invention, processing time 1
5 minutes, concentricity of cylindrical surface is 46 μm, squareness of cut surface is 12
μm was obtained.

[0020]

According to the present invention, the average axis of the bent tubular ceramic molded body can be determined and chucked, and a plurality of processes can be performed without using a plurality of machine tools.
Processing can be performed with a single chuck, and improvement in processing efficiency can be realized.

In addition, as compared with the case where a plurality of machine tools are used, it is possible to prevent deterioration in accuracy due to whirling and shaft fall when re-chucking. As described above, according to the present invention, it is possible to improve the processing accuracy and processing efficiency of a workpiece.

[Brief description of the drawings]

FIG. 1 is a perspective view of a processing apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a sodium-sulfur battery.

FIG. 3 is a view showing a shape of a bent tubular ceramic molded body.

FIG. 4 is a top view of a relative position of a workpiece and a grindstone attached to a grindstone shaft during a cutting process.

FIG. 5 is a top view of the relative positions of the workpiece and the grindstone attached to the grindstone shaft during cylindrical surface machining.

[Explanation of symbols]

1 ... β-alumina tube molded body, 2 ... α-alumina,
3 ... Positive electrode tube, 4 ... Sulfur layer, 5 ... Safety tube, 6 ... Machine tool, 7A, 7B ... Chuck mechanism, 8 ... Spindle, 9 ... XY table,
Reference numeral 10: cutting whetstone, 11: whetstone for cylindrical surface processing, 12: whetstone shaft, 13 to 16: relative movement direction of whetstone shaft and workpiece.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Katsumi Imagawa 3-10-2 Bentencho, Hitachi City, Ibaraki Prefecture Hitachi Kyowa Kogyo Co., Ltd.

Claims (3)

[Claims] In a method for cutting a tubular ceramic molded body and processing an outer diameter in the vicinity of a cut portion, a cutting grindstone attached to a same grinding wheel shaft at predetermined intervals after chucking the tubular ceramic molded body, and cylindrical surface processing. A cutting method of a tubular ceramic molded body, wherein cutting and cylindrical surface machining are continuously performed while rotating the molded body using a grinding wheel. 2. The method for processing a tubular ceramic molded article according to claim 1, wherein the tubular ceramic molded article is a β-alumina tubular molded article. 3. An apparatus for processing a tubular ceramic molded body, characterized by the processing method according to claim 1.