JP3980333B2 - Method for dividing ceramic cylindrical body - Google Patents

Description

【００３５】
【発明の効果】
以上の通り本発明によれば、以下の作用効果を奏する。
（１） 脆性材料の破壊作用を利用しているので、切削屑や熱の発生がなく、そのため環境に与える影響が少なく、きれいな職場環境を維持できる。
（２） また、荷重が負荷されている円筒体は分割まで弾性変形するので、分割に必要なエネルギーは僅かであり、省エネルギー的な分割方法である。
（３） しかも、分割後の接合が確実で寸法上の変化がないので、軸スリーブ等の分割に有効である。
（４） 切欠き部や荷重を負荷する位置を選択することで、縦断面における２等分割、４等分割、１／４分割、あるいは、３等分割、任意の角度での分割を行うことができる。
（５） オールドセラミックスのガラスを含めてニューセラミックスの分割に適用でき、岩石などのような脆性材料も分割可能である。
（６） またストレート状の円筒体のみならずメカニカルシールの密封摺動環のような異形環や異形円筒体に対しても適用できる。
【図面の簡単な説明】
【図１】最大引張応力の発生位置を示す正面図。
【図２】本発明を実施するために円筒体に切欠き部を形成する一実施形態を示す斜視図。
【図３】切欠き部を形成した円筒体に圧縮荷重を負荷する状態を示す正面図。
【図４】図３の側断面図。
【図５】分割された円筒体を示す斜視図。
【図６】外表面に切欠き部を設けて２等分割する場合を説明する正面図。
【図７】４等分割する場合を説明する正面図。
【図８】１／４分割する場合を説明する正面図。
【図９】３等分割する場合を説明する正面図。
【図１０】任意角度での分割の第１分割工程を説明する正面図。
【図１１】図１０の第２分割工程を説明する正面図。
【符号の説明】
１、１Ａ〜１Ｅ・・・円筒体
Ｎ０１〜・・・（円筒体の外表面の）切欠き部
Ｎ１１〜・・・（円筒体の内表面の）切欠き部
２・・・下板
３・・・上板
Ｓ０・・・円筒体の外表面
Ｓ１・・・円筒体の内表面
Ｗ、ｗ、ｗ′・・・荷重[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for dividing a ceramic cylindrical body.
[0002]
[Prior art]
For example, a ceramic cylindrical body is used for a sleeve-like casing used for shaft coupling or the like. Such a sleeve-like cylindrical body is divided into two in the axial direction (longitudinal direction), and when these are assembled to a shaft and joined together, repair and maintenance become easy.
[0003]
However, when the cylindrical body is cut in the axial direction with a saw, for example, the thickness of the saw blade is removed, so that the dimensions, particularly the inner diameter, differ between the production of the cylinder and the joining after cutting. .
[0004]
Of course, it is possible to make a cylindrical body in consideration of the cut dimensions, but there are many errors at the time of cutting, and it is unsuitable for use as an accurate sleeve.
[0005]
Japanese Patent Publication No. 58-55388 discloses a technique relating to the manufacture of a sealed sliding ring of a mechanical seal. In this technology, a jig with a large thermal expansion coefficient is inserted inside the cylinder, and the jig is heated and expanded to divide the cylinder, or the inner space of the cylinder is pressed radially outward. In both cases, the cylindrical body is divided, and both are divided by applying a load radially outward to the entire inner surface of the cylindrical body and generating a tensile stress in the circumferential direction. In the former, a jig suitable for the inner diameter of the cylindrical body is required, and in the latter, it is necessary to prevent pressure leakage due to pressurization. For this reason, the precision of each part becomes important, and the cylindrical body cannot be divided easily.
[0006]
In Japanese Patent Publication No. 39-16854, two seal rings each having a sealing surface extending in the diametrical direction are respectively supported by a housing and a shaft so that the sealing surfaces are opposed to each other. A technique for a sealing device that is divided and provided with the divided portions close to each other is disclosed.
However, the division shown in this technique depends on the length of the cylinder, and a long cylinder cannot be divided.
[0007]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a method for dividing a ceramic cylinder that easily divides a ceramic cylinder along the axial direction and that does not cause a substantial difference in dimensions even after joining after division. Is to provide.
[0008]
[Knowledge]
As a result of various studies, the inventor forms a notch in the axial direction of the cylindrical body, and when a static load, that is, a compressive force is applied in the diametrical direction, the cylindrical body is divided and cut along the notch, Moreover, it has been found that if the joint surface is not processed, both can be joined in close contact.
[0009]
[Means for Solving the Problems]
According to the method for dividing a ceramic cylindrical body of the present invention, a ceramic cylindrical body is prepared, and at least two locations on the inner surface of the ceramic cylindrical body are formed with notches extending in the axial direction, A compressive load in the diametrical direction is applied to the outer surface of the ceramic cylinder, so that the ceramic cylinder is divided along the notch.
[0010]
When a compressive load is applied in the diameter direction of a ceramic cylinder, bending stress is generated in each cross section of the cylinder, and as shown in FIG. 1, when a compressive load W is applied to two points in the vertical diameter direction, the cylinder Maximum tensile stresses are generated at the positions of the inner surface A in the load direction of the body 1 and the outer surface B in the direction perpendicular thereto. On the other hand, the tensile strength of ceramics is small compared to the compressive strength. The dividing method of the present invention effectively utilizes the tensile stress induced in the cylindrical body and the cracks generated at the time of tensile failure of the ceramic, and divides the cylindrical body in a longitudinal section in a single compression step.
[0011]
That is, a notch is formed at a desired division position on the inner surface or outer surface of the cylindrical body with a tool such as a glass cutter or a diamond wheel. Next, if a cylindrical body is arranged so that the maximum tensile stress is induced in the notch and a compressive load is applied, when the stress induced in the notch of the cylinder reaches the tensile strength, A crack occurs from the notch.
The crack generated from the notch is used to divide the cylindrical body. When a compressive load is applied to two points in the longitudinal section, the cylindrical body can be divided into two equal parts, and the position where the notch is provided is selected. By doing so, it is possible to perform a quarter division or a quarter division.
[0012]
In addition, according to the present invention, the position of the notch is appropriately selected, and the compression load in the diametrical direction is applied to the three points in the longitudinal section, thereby dividing into three equal parts or at an arbitrary angle (three-point compression). Division) can also be performed. The compressive load in the diametrical direction in the longitudinal section may be applied by inserting the cylindrical body into a V-shaped groove that contacts at a predetermined load point.
[0013]
In carrying out the present invention, the notch portion does not need to be provided over the entire length of the cylindrical body in the axial direction, and the cross-sectional shape of the notch portion is usually V-shaped, but is not limited thereto. Absent. In addition, a notch part in which a groove having a V-shaped shape is formed in advance in the cylindrical body may be used.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 2, a ceramic cylindrical body 1 is prepared, and extends in the axial direction to positions A and A on the inner surface S1 of the cylindrical body 1 that are angularly separated by 180 degrees using a tool T such as glass cutting. Linear notches N11 and N12 are formed.
[0015]
Next, as shown in FIGS. 3 and 4, the ceramic cylindrical body 1 having the outer diameter D0, the inner diameter D1, and the length L, in which the notches N11 and N12 are formed, is placed on a pressing device, for example, the lower plate 2 of the press. Then, a uniform compression load W is applied as a whole by the upper plate 3 operated by a ram (not shown).
[0016]
As shown in the figure, when the compressive load W is gradually increased at the positions of the notches N11 and N12, a bending moment proportional to the compressive load W is generated in the cylindrical body 1 and provided on the inner surface S1 of the cylindrical body 1. The maximum tensile stress is generated at the notches N11 and N12, and concentrated stress is superimposed because the notches N11 and N12 are present.
[0017]
Therefore, when the compressive load W reaches a certain value, cracks are generated in the notches N11 and N12, and the crack propagates outward in the radial direction. As shown in FIG. 1b. At that time, since the cylindrical body 1 is elastically deformed, the cylindrical shape is maintained even when the cylindrical body 1 is divided into the halves 1a and 1b.
[0018]
Therefore, the half part 1a, 1b can reproduce the same dimension as the cylindrical body 1 by joining.
[0019]
Another embodiment is shown in FIG. As shown in the drawing, the cylindrical body 1A is arranged and a compressive load W is applied so that the notches N01 and N02 in the outer surface S0 of the cylindrical body 1A have the maximum tensile stress. At this time, if the stress induced in the notches N01 and N02 reaches the tensile strength of the ceramic, a crack propagates from the notch toward the inner surface S1 of the cylindrical body 1A, and the cylindrical body 1A has a single compression process. The cylindrical body 1A is divided into two equal parts in the horizontal diameter direction.
[0020]
In the case where the cylindrical body is divided into four equal parts, as shown in FIG. 7, notches N01, N02 and N11, N12 respectively provided on the outer surface S0 and the inner surface S1 of the cylindrical body 1B have the maximum value of tensile stress. In order to do so, the cylindrical body 1B is arranged and a compressive load W is applied. At this time, if the stress induced in each notch N01, N02, N11, N12 reaches the tensile strength of the ceramic, the crack propagates from the notch toward the outer surface S0 and the inner surface S1 of the cylindrical body. The cylindrical body 1B is divided into four equal parts by the compression process.
[0021]
In the case of quarter division of the cylindrical body, as shown in FIG. 8, the notches N01 and N11 in the outer surface S0 and the inner surface S1 of the cylindrical body 1C are set to the maximum value of the tensile stress. Therefore, the cylindrical body 1 </ b> C is arranged to apply the compressive load W. At this time, if the stress induced in the notches N01 and N11 reaches the tensile strength of the ceramic, cracks propagate from each notch, and the cylindrical body 1C is divided into 1/4 by one compression process.
[0022]
The embodiment in which the compression load W is applied to two points in the vertical diameter direction of the cylindrical body and the cylindrical body is divided in the longitudinal section has been described above. According to this embodiment, when the notch is provided on the outer surface S0 of the cylindrical body and when it is provided on the inner surface S1, the compression load at the time of division can be reduced by providing it on the inner surface S1. Therefore, paying attention to the case where the notch is provided on the inner surface S1 of the cylinder, compressive loads W (W, W ') are applied to the three points of the cylinder as shown in FIGS. Next, division into three equal parts on a surface or division at an arbitrary angle will be described.
[0023]
As shown in FIG. 9, when the cylindrical body is divided into three equal parts, in order to divide the cylindrical body 1D into three equal parts in one compression step, three notches N11 to N13 are provided on the inner surface S1 of the cylindrical body 1D. The cylindrical body 1D is disposed so that the maximum tensile stress is induced in each of the notches N11 to N13, and the compressive load W is statically applied. At this time, when the compression load W reaches a certain value, cracks propagate from the notches N11 to N13, and the cylindrical body 1D is divided into three equal parts in one compression process.
[0024]
Further, when the cylindrical body is divided at an arbitrary angle, the cylindrical body 1E is divided by a longitudinal section at an arbitrary angle θ, so that the notch N11 and the angle θ formed therewith are formed on the inner surface S1 of the cylindrical body 1E. A notch N12 is provided at the position, and compressive loads W and w are applied to three points of the cylindrical body 1E as shown in FIG. The values of the compression loads W and w at this time depend on the angle α, but if α <60 °, W> w. When the compression load W is applied in this state, the first division first occurs at the notch N11. Next, the compression load W is unloaded, and the cylindrical body 1E is rearranged again to be divided at the notch portion N12 as shown in FIG. 11, and the compression load W is subsequently applied for the second division. In this way, a crack propagates from the notch N12 with a certain value of the compressive load W, and can be divided at an arbitrary desired angle θ. In this case, the compression process is performed twice.
[0025]
[Experiment 1]
Hereinafter, each experimental example for the above embodiment will be described.
As the test piece, select the glass “Pyrex (registered trademark)” which is an old ceramic, and provide a notch in the cylindrical body on the inner or outer surface of the cylindrical body to statically apply a compressive load. Was divided into two in one compression step by the above-mentioned various dividing methods in a longitudinal section.
In FIG. 4, the dimensions of the cylindrical body 1 are an outer diameter D0 = 60 mm, an inner diameter D1 = 51 mm, and an axial length L = 30 mm. A tool for providing a notch for designating the position of division was a commercially available diamond pen. The notch at that time had a width of 4 μm and a depth of 281 μm. Hereinafter, an experimental example of division using the prepared cylindrical body 1 will be described.
[0026]
As an experimental example of two equal divisions, the notches N11 and N12 of the cylindrical body 1 were provided on the inner surface S1 of the cylindrical body 1 as shown in FIG. The cylindrical body 1 was divided into two equal parts in a longitudinal section passing through the notches N11 and N12 by generating a slight beeping sound twice with substantially the same compression load at a compression load W = 20 kgf. The dividing surfaces at this time were all smooth.
[0027]
Moreover, as shown in FIG. 6, the notches N01 and N02 of the cylindrical body 1A were provided on the outer surface S0 of the cylindrical body 1A to apply a compressive load W to the cylindrical body 1A. The cylindrical body 1A was divided into two equal parts in a longitudinal section passing through the notches N01 and N02 by emitting a weak beep twice with a compression load W = 85 kgf. The dividing surface at this time was also smooth.
[0028]
When attention is paid to the compression load W at the time of division, the notches N11 and N12 are provided on the inner surface S1 of the cylindrical body when the notches N01 and N02 are provided on the outer surface S0 of the cylindrical body. It was given 4 times higher than the case. Therefore, when the cylindrical body is divided, the compression load W at the time of division can be reduced in the case of FIG. 3 in which the notch is provided on the inner surface S1.
[0029]
In addition, as an experimental example of four equal divisions, notches N01, N02 and N11, N12 are provided on the outer surface S0 and the inner surface S1 of the cylindrical body 1B as shown in FIG. 7, and each notch is tensioned. In order to obtain the maximum value of the stress, the cylindrical body 1B was arranged and a compressive load W was applied. In the cylindrical body 1B, with the compressive load W = 16 kgf, splitting occurred almost simultaneously at two notches N11 and N12 provided on the inner surface S1 of the cylindrical body 1B, and the cylindrical body 1B was divided into two equal parts. At this time, the cylindrical body 1B maintains its shape even if the cylindrical body 1B is first divided at the notches N11 and N12. Therefore, in this state, the compression load W is further applied, and the division continues at the notches N01 and N02 provided at two locations on the outer surface S0 of the cylinder 1B with the compression load W = 17 kgf. It was divided into 4 equal parts.
[0030]
As an experimental example of 1/4 division, notches N01 and N11 are provided on the outer surface S0 and the inner surface S1 of the cylindrical body 1C as shown in FIG. 8, and each notch has a tensile stress. The cylindrical body 1C was placed and a compressive load W was applied so as to obtain the maximum value. In the cylindrical body 1C, a crack first propagates at a notch N11 provided on the inner surface S1 of the cylindrical body 1C with a compressive load W = 18 kgf, and when the compressive load W is further applied, the cylindrical body 1C continues with the compressive load W = 41 kgf. Cracks propagated through the notch N01 provided on the outer surface S0, and the cylindrical body 1C was divided into quarters as desired.
[0031]
[Experimental example 2]
Next, an experimental example of three-point compression division will be described.
The prepared test piece is a cylindrical body made of glass as in the case of Experimental Example 1, and the dimensions are an outer diameter D0 = 60 mm, an inner diameter D1 = 51 mm, and an axial length L = 30 mm. The notch of the cylindrical body was provided on the inner surface of the cylindrical body, and the compressive load was statically applied. A tool for providing a notch is also a commercially available diamond pen as in the first experimental example.
[0032]
As an experimental example of three equal divisions, in order to divide the cylindrical body 1D into three equal divisions as shown in FIG. 9, notches N11 to N13 are provided on the inner surface S1 of the cylindrical body 1D, and a compression load W is applied to the cylindrical body 1D. did. Cylindrical body 1D was divided into three equal parts with cracks propagating from notches N11 to N13 with compression load W = 27 kgf. Each of the obtained divided surfaces was good.
[0033]
Further, as an experimental example of division at various angles, the inner surface S1 of the cylindrical body 1E is cut to be divided at various angles θ = 30 °, 60 °, 90 °, 120 °, and 150 ° of the cylindrical body 1E. Notches N11 and N12 were provided, and a compressive load W was applied to the cylindrical body 1E as shown in FIG. The value of angle α at this time was α = 45 °. Initially, the crack by the 1st division propagated from notch N11 with compression load W1. Next, the compressive load W was unloaded, and the cylindrical body 1E was again arranged as shown in FIG. 11, and the compressive load W was subsequently applied for the second division at the notch N12. Splitting occurred with compressive load W2.
[0034]
The compression loads W1 and W2 at the time of division at the notches N11 and N12 were the values shown in Table 1, respectively. In addition, although the division | segmentation in this case requires the compression process of 2 times, it was not only able to divide | segment by the desired angle (theta), but the obtained division surface was also favorable.

[0035]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
(1) Since the destructive action of brittle materials is used, there is no generation of cutting waste and heat, so there is little impact on the environment and a clean work environment can be maintained.
(2) Moreover, since the cylindrical body to which the load is applied is elastically deformed until the division, the energy required for the division is small, and this is an energy-saving division method.
(3) Moreover, since the joining after the division is reliable and there is no dimensional change, it is effective for the division of the shaft sleeve and the like.
(4) By selecting a notch and a position where a load is applied, the vertical section can be divided into two equal parts, four parts, 1/4 parts, or three parts, or an arbitrary angle. it can.
(5) It can be applied to the division of new ceramics including glass of old ceramics, and brittle materials such as rocks can also be divided.
(6) Further, the present invention can be applied not only to a straight cylindrical body but also to a deformed ring or a deformed cylindrical body such as a sealed sliding ring of a mechanical seal.
[Brief description of the drawings]
FIG. 1 is a front view showing a position where a maximum tensile stress is generated.
FIG. 2 is a perspective view showing an embodiment in which a notch is formed in a cylindrical body in order to carry out the present invention.
FIG. 3 is a front view showing a state in which a compressive load is applied to a cylindrical body in which a notch is formed.
4 is a side sectional view of FIG. 3;
FIG. 5 is a perspective view showing a divided cylindrical body.
FIG. 6 is a front view for explaining a case where a notch portion is provided on the outer surface and divided into two equal parts.
FIG. 7 is a front view for explaining a case where four equal divisions are performed.
FIG. 8 is a front view for explaining a case of 1/4 division.
FIG. 9 is a front view for explaining the case of three equal divisions.
FIG. 10 is a front view illustrating a first division process of division at an arbitrary angle.
FIG. 11 is a front view for explaining the second dividing step in FIG. 10;
[Explanation of symbols]
1, 1A to 1E... Cylindrical body N01 to... Notched portion N11 to... (Noted portion of inner surface of cylindrical body) 2. ..Upper plate S0 ... Outer surface S1 of cylindrical body ... Inner surface W, w, w '... load of cylindrical body

Claims (3)

  Prepare a ceramic cylinder, form notches extending in the axial direction at at least two locations on the inner surface of the ceramic cylinder, and then apply a compressive load in the diametrical direction to the outer surface of the ceramic cylinder. A method for dividing a ceramic cylinder, comprising: applying a load, and dividing the ceramic cylinder along the notch.   2. The method of dividing a ceramic cylindrical body according to claim 1, wherein the notch has a size within a range of elastic deformation of the cylindrical body due to a compressive load and is cracked by a tensile stress due to a bending moment.   The method for dividing a ceramic cylindrical body according to claim 1 or 2, wherein a compressive load in a diametrical direction is applied to the outer surface of the cylindrical body as the compressive load.

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