JPH05221673A - Cutting process - Google Patents

Abstract

PURPOSE:To facilitate cutting of a brittle material plate along a desired curve without chipping and to make the cut surface smooth in the subject cutting process of the plate. CONSTITUTION:In a cutting method by making a partial cut (3) in the outer peripheral part of a plate (W) made of a brittle material, subsequently moving a cutting-heater along a prescribed cutting line (L) starting from the above- mentioned partial cut (3) and advancing cutting of the plate from the above- mentioned partial cut (3) as the starting point, the part of the above-mentioned plate (W) along the above-mentioned cutting line (L) is preheated. A fine cut is preliminarily made along the above-mentioned prescribed cutting line (L) on the surface of the above-mentioned plate (W).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a partial cutting groove on an outer peripheral portion of a plate made of a brittle material such as glass, tile, or ceramics, and follows a target cutting line starting from the partial cutting groove. The present invention relates to a cleaving method for moving a cleaving heating body while advancing the cleaving of a plate body starting from the partial cutting groove. INDUSTRIAL APPLICABILITY The present invention can be used for cutting an arbitrary shape at the time of producing stained glass, cutting glass in glass crafts and glass industry, cutting tiles in general households, curved cutting of engineering ceramics, and the like.

[0002]

2. Description of the Related Art Conventionally, in the field of stained glass and glass crafts, diamond glass cutting and oil cutters have been used together with sophisticated tools to respond to the demands of curve cutting with skill and labor. Recently, a diamond hand saw has been used for cutting of small products, but there are still many problems such as chipping problem and processing of large products. Even in high-tech technologies such as laser processing, problems such as fusing of ceramic plates with a thickness of about 5 mm or more, fine damage in the vicinity of the molten surface, finishing of the molten surface, and processing of large-sized products remain unsolved.

As a method of cutting brittle materials such as glass and tiles into a smooth cut surface without chipping, the following cutting method has been used for a long time. That is, in the cleaving method, a notched groove (microfabricated groove) is formed in a shape to be cleaved on a flat plate using diamond glass cutting, and then bending stress is mainly applied to concentrate stress on the notch bottom. It is a method of breaking it by causing it. This conventional cleaving method requires skill and a great deal of labor even when cleaving a curve having a large curvature.

Further, in the cutting process on the curved line of glass, a high amperage (about 50 A) current is applied to a nichrome wire arranged in a predetermined shape to heat it, and watering causes local shrinkage at one end to cause cracking. There is also a method to do this, but since the propagation speed of this crack is extremely high (about 500 m / sec), it is not easy to cleave the shape desired by the manufacturer,
It has not been widely used.

In recent years, a seamless diamond band saw has been put to practical use for cutting of relatively low strength engineering ceramics such as glass, tile and alumina.
The cutting of large glass and the processing of high-strength ceramics still remain difficult. With the various conventional processing methods described above, it is impossible to cut a plate made of a brittle material such as glass, tile, or ceramic with a smooth cut surface along a curved line without causing chipping.

[0006]

By the way, recently, a fine fractured portion as a fracture starting point is formed on a brittle plate, and a heating body for fracture is moved along a fracture target line starting from the fine processing cracked portion. Cleaving method for advancing the cleaving of the plate body starting from the starting point (Paper No. 55, No. 509, 1989-1, Paper No. 88-
0157B, "Possibility of Cleaving of Brittle Materials by Thermal Stress", and Transactions of the Japan Society of Mechanical Engineers, 1990-4,
Paper No. 89-0284B, "Propagation of cracks due to thermal stress under circular uniform heating", etc.) is proposed. However, even if an attempt was made to cut a brittle material plate into a curved shape by the cutting method described in these documents, the plate could not be cut into a curved shape as desired. The reason is considered to be as follows. That is, in the conventional cleaving method that does not perform preheating, the cleaving (crack) propagates linearly at a high speed (unstable fracture) over a length of about 2 to 5 times the plate thickness and stops. It is considered that this is because the energy of initiation when cracking (crack) begins to grow is large. Therefore, for example, even when it is desired to cut into a circle, the actual cutting process is a polygonal cut, and it is difficult to perform a smooth curved cut.

What is particularly necessary in the cutting process of a plate formed of a brittle material is that it is possible to perform cutting on a so-called curved line having a complicated shape from an engineering point of view, and a cutting cross section and its vicinity at the time of cutting. The two points are that there is no chipping or fine damage cracking. In particular, the chipping and fine cracks markedly reduce the strength of the product. Therefore, in order to maintain the strength of the product, it is necessary to maintain the state of the processed surface in good condition (without scratches and smoothly).

In view of the above-mentioned circumstances, it is an object of the present invention to make it possible to easily divide a brittle material plate body along a desired curve without chipping, with a smooth processed cross section.

[0009]

Next, the invention of the present application devised to solve the above-mentioned problems will be described. Components of the present invention correspond to those of embodiments described later. For the sake of clarity, reference numerals of constituent elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments. The plate cutting method of the first invention of the present application is
A partial cutting groove (3) is formed on an outer peripheral portion of a plate body (W) made of a brittle material, and a heating body for cutting () is provided along a cutting target line (L) starting from the partial cutting groove (3). 5) In the cleaving method of moving the plate body starting from the partial cutting groove (3) while moving the plate, the part of the plate body (W) along the target cleavage line (L) is preheated. It is characterized by doing.

The plate body cleaving method of the second invention of the present application is the plate body cleaving method of the first invention,
It is characterized in that a fine processed groove (4) is formed in advance on the surface of the plate body (W) along the cleavage target line (L).

[0011]

In the cleaving method of the first invention of the present application, part or all of the cleaving target line (L) of the brittle material plate (W) is preheated. The brittle material is an inorganic material such as glass or ceramic, and most of such materials have low thermal conductivity. Therefore, it is possible to locally preheat the portion of the plate body (W) made of the brittle material along the cleavage target line (L). The preheating temperature is determined by the elastic modulus and the coefficient of thermal expansion of the plate (workpiece) (W), but is approximately 50 to 250 ° C. As a means for preheating the plate body (W), a heating wire (preheating body) (2) having the same shape as the cleavage target line (L) is brought into contact with the lower surface of the plate body (W), or It is possible to adopt a method of moving the object (preheated body) (12) held at the heating temperature (12) in a contact or non-contact manner along the cleavage target line (L) on the surface of the plate body (W). is there.

The cleaving heater (5) is moved along the cleaving target line (L) starting from the partial cutting groove (3) on the surface of the preheated plate (W). The movement of the heating body for cleaving (5) is performed in a state where the object (heating body for cleaving) (5) held at the heating temperature for cleaving is brought into contact with or non-contact with the surface of the plate body (W). You can The front part of the crack (about 0.5 to 3 times the plate thickness) is heated in contact or non-contact with the heating body (5) for cleaving, and the local thermal stress field is superposed on that by the previous preheating and heating for cleaving. When the body is moved along the cleavage target line (L), the cleavage of the plate body (W) starting from the partial cutting groove (3) progresses due to the movement of the heating body for cleaving (5).

Since the speed of cleaving depends on the preheating temperature and the heating temperature for cleaving, the physical properties of the object to be cleaved (plate made of brittle material) (W), the curvature of the target cleaving line (L), etc., it is difficult to formulate it. However, depending on the parameters of the cleaving (physical properties of the object to be cleaved (plate made of brittle material), thickness, curvature of the cleaving target line, etc., preheating temperature of the plate, heating temperature for cleaving, or Optimum conditions such as the moving speed of the cleaving heating element) can be relatively easily found by short-term experience.

The cleaving method of the second invention of the present application having the above-mentioned characteristics is the cleaving method of the first invention, wherein:
Since the fine processed groove (4) is formed in advance on the surface of the plate (W) along the target cutting line (L), it is easy to match the actual cutting line with the target cutting line (L). is there. In the case of the second invention, when the plate body (W) made of a high-strength or thick brittle material is cleaved, even if the heating area by the cleaving heater (5) is increased in order to improve the temperature rising characteristics, The breaking line is less likely to deviate from the desired breaking target line (L). The fine processing grooves (4) formed in advance on the surface of the plate body (W) along the target cutting line (L) can be formed by a diamond tool or jet processing.

[0015]

EXAMPLES Examples of the cleaving method of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples.

[First Embodiment] FIG. 1 is a plan view of a first embodiment of a cleaving apparatus for carrying out the cleaving method of the present invention.
2 is a side sectional view of the first embodiment and is a sectional view taken along line II-II of FIG. In FIG. 2, a preheating body 2 is provided on the upper surface of the base 1. The preheating body 2 is composed of a heart-shaped heating wire, and when power is supplied from the power supply line, it generates heat and its temperature rises. A plate W (see FIG. 1) made of a brittle material made of ceramics is placed on the upper surface of the pedestal 1 in contact with the preheater 2. The portion of the plate W that contacts the preheater 2 is the target cleavage line L.

A partial cutting groove 3 is formed on the outer peripheral portion of the plate W so as to connect to the target cutting line L. The partial cutting groove 3 is for smoothly starting the cutting of the plate W, and is formed by cutting diamond glass or an indenter. In addition, in order to improve the dimensional accuracy of the product on the surface of the plate W, a desired target cutting line L
Along with the diamond thickness (1
/ 20) to (1/50) microfabrication groove 4 (FIG. 3,
4) is formed.

In FIG. 3, the cleaving heating unit U handled by the operator is moved on the surface of the plate W along a cleaving target line L starting from the partial cutting groove 3 as a starting point. The cleaving heating unit U has an iron shape as a whole so that it can be easily operated manually. The cleaving heating unit U includes a cleaving heating body 5 and a heating body supporting member 6 that supports the cleaving heating body 5. The heating body for cleaving 5 is formed in a rod shape as a whole, and is provided with a heat generating portion 5a on the front end side and a guided portion 5b made of a heat resistant material on the base end side. The heater support member 6 is
It has a handle 7 and a guide tube 8. Guide tube 8
The guided portion 5b of the cleaving heating body 5 is slidably supported in the vertical direction.

A compression spring 9 is provided between the cleaving heating element 5 and the heating element supporting member 6. The compression spring 9 has a function of constantly pressing the cleaving heating body 5 downward so that the heat generating portion 5a comes into contact with the plate W. The cleaving heating element 5 pressed downward is provided with a positioning projection 5c, and the lower limit position of the cleaving heating element 5 is restricted by the projection 5c.

Next, the operation of the first embodiment will be described with reference to the operation explanatory views of FIGS. As shown in FIG. 5, the lower surface of the plate W made of brittle material is preheated along the cleavage target line L by the preheater 2 (see FIG. 2). If the temperature of the portion along the cleavage target line L becomes Ts due to this preheating, pulling stress σs occurs at the end face, and this stress value σs is approximately αETs (α and E are the linear expansion coefficient of the plate W and Longitudinal elastic modulus). In order for this stress σs to reach the tensile strength of the object (plate W), Ts * = 50 to 150 ° C for glass and Ts * = 150 to 250 ° C for engineering ceramics such as alumina and zirconia. (When cutting is actually performed, ideal linear heating as described above cannot be performed, so Ts * can be estimated to be about 50% higher.) However, if the temperature exceeds Ts *, the fracture propagates at an ultra-high speed. In most cases, it is almost impossible to control the fracture shape in the form of unstable fracture. Therefore, in this method, this preheating temperature is set to about room temperature to (2/3) Ts *.

Next, when one side of the plate W is heated by the cleaving heater 4 as shown in FIG. 6, a new thermal stress field is superposed on the previous stress field. The thermal stress field due to the heating element 4 for cutting is local as shown in FIG. 7, and the hatch portion before heating is thermally expanded like the dotted line portion by the heating of the heating element 4 for cleaving. Tensile stress is induced in the AB portion of FIG. 5, the tensile strength of the material is reached, and cracks start to develop. When this heating body 5 for cleaving is moved along the target line L for cleaving in the direction of arrow A in FIG. 8, cracks are dragged by this thermal stress and propagate stably, and the plate body (workpiece) W is freely movable. It is cut into the shape of. The cleaving speed is controlled by properly combining the above-mentioned preheating temperature and the heating area by the preheating body 2 with the heating temperature for cleaving and the heating area by the cleaving heating body 5.

Further, in this embodiment, as shown in FIGS. 2 to 4, since the plate body W is formed with the partial cutting groove 3 connected to the target cutting line L on the outer peripheral portion thereof, The cutting of the body W starts extremely smoothly. Further, in this embodiment, since the fine processed groove 4 is formed on the surface of the plate body W, it is possible to perform a very good cutting process.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, instead of the preheater 2 provided on the upper surface of the pedestal 1 of the first embodiment, a concave groove 11 is formed.
Is provided, and the preheating body 12 is provided in the heating unit for cleaving U, and the like, which is different from the first embodiment. In the description of the second embodiment, the first embodiment will be described.
The same reference numerals are given to the constituent elements corresponding to those constituent elements, and detailed description thereof will be omitted.

In FIGS. 9 and 10, the heating unit for cleaving U is provided with a preheating body 12 in addition to the heating member supporting member 6 and the heating member for cleaving 5 as in the first embodiment. The preheating body 12 is formed in a rod shape as a whole,
The heat generating portion 12a on the front end side and the guided portion 12b made of a heat resistant material on the base end side are provided. The heater support member 6 is
The preheater 12 has a guide tube 13 that supports the preheater 12, and the guided portion 12b of the preheater 12 is supported by the guide tube 13 so as to be slidable vertically.

A compression spring 14 is provided between the preheating body 12 and the heating body supporting member 6. The compression spring 14 has a function of constantly pressing the preheating body 12 downward to bring the heat generating portion 12a into contact with the plate W. The preheating body 12 pressed downward is provided with a positioning projection 12c, and the lower limit position of the preheating body 12 is restricted by the projection 12c. In the second embodiment, the power consumption of the preheating body 12 is 50 to 100 W and the power consumption of the cleaving heating body 4 is 10 W.
It is variably set from 0 to 200W.

In the second embodiment, since the concave groove 11 on the upper surface of the pedestal 1 is provided along the breaking target line L, when the heating unit for cutting U is moved, the compression springs 8 and 14 work. A bending stress acts on the plate W. Therefore, the cutting is smoothly performed.

In each of the above-mentioned embodiments, since the heating element by electric heating is used as the means for preheating the plate W and the means for heating the plate W for cutting, as compared with the case of using the laser beam. Easy to handle. Therefore, each of the above-described embodiments is excellent in safety and economy.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. It is possible to make design changes. For example, instead of moving the cleaving heating unit U in the second embodiment, the plate W can be moved.

[0029]

According to the above-described cleaving method of the present invention, since the portion of the plate body along the cleaving target line is preheated, there is no chipping, the machined section is smooth, and the brittle material plate is formed along a desired curve. You can easily divide your body.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of a cleaving apparatus for carrying out the cleaving method of the present invention.

FIG. 2 is a side sectional view of the first embodiment, which is taken along line II of FIG.
FIG. 6 is a sectional view taken along line II.

FIG. 3 is an explanatory diagram of a cleaving heating unit U according to the first embodiment.

FIG. 4 is an explanatory diagram of a plate body W used in the first embodiment.

FIG. 5 is an operation explanatory view in the cleaving process of the first embodiment.

FIG. 6 is an operation explanatory view in the cleaving process of the first embodiment.

FIG. 7 is an operation explanatory view in the cleaving process of the first embodiment.

FIG. 8 is an operation explanatory view of the cleaving process of the first embodiment.

FIG. 9 is an explanatory view of a second embodiment of a cleaving apparatus for carrying out the cleaving method of the present invention.

FIG. 10 is an explanatory diagram of the second embodiment, which is similar to FIG.
6 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

L ... Cleaving target line, U ... Cleaving heating unit, W ... Plate, 2 ... Preheating body, 3 ... Partial cutting groove, 4 ... Machining groove, 5
… Cleaving heating element, 12… Preheating element

Claims (2)

[Claims] 1. A partial cutting groove is formed in an outer peripheral portion of a plate body made of a brittle material, and the partial cutting groove is moved while moving a heating body for cutting along a cutting target line starting from the partial cutting groove. A cleaving method for advancing the cleaving of a plate starting from a groove, characterized by preheating a portion of the plate along the target cleavage line. 2. The cleaving method according to claim 1, wherein fine machining grooves are formed in advance on the surface of the plate body along the cleaving target line.