JPH0442A - Chain and manufacture thereof - Google Patents

Abstract

PURPOSE:To manufacture chain without using a special method by performing shrinkage from the green material to the sintered material with degreasing and sintering earlier than shrinkage of an engaging hole of a first parts, and connecting a second parts having engaging projections. CONSTITUTION:A first and a second parts 10, 11 are formed as the green material by injection molding. A compounding ratio of ceramic powder or metal powder and a binder is selected appropreately to adjust a shrinkage ratio. The first parts 10 has engaging holes 12a and a hollow part 13. The second parts 11 has engaging projections 15 formed in right and left ends of an axis part 14. Under the green material condition, the relation of each dimension is k<Dg<dg<Wg, and under the degreased material condition, shrinkage thereof is a very little. Next, when only the second parts 11 is sintered, a dimension ds becomes smaller than a dimension Dg, the engaging projections 15 are inserted into the hollow parts 13 to be engaged, and when sintering is performed, the first parts 10 is shrinked at 15-25% to conclude the connection, and a chain 17 is thereby manufactured.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a chain and a method for manufacturing the same, and particularly relates to a method for joining parts by utilizing the shrinkage of powdered materials such as ceramics or metals due to sintering. The present invention relates to a chain for producing a chain-like combined body (chain) and a method for producing the same.

[Prior Art] Figures m9 and 10 are perspective views of a conventional chain] and 2, respectively. These are composed of a combination of each element 3.4. In manufacturing such a conventional chain 1.2, each element 3.4 is constructed from a cast product or a processed product, and these are assembled. Further, each element 3.4 is processed into a sintered body or green body by injection molding or other molding means from ceramic or metal powder, and then assembled.

However, in such a chain 1.2, processing of each element 3.4 is labor-intensive and expensive, small-sized ones are difficult to manufacture, and because the chain is belt-shaped, the entire chain can only be bent in one direction. Is there a problem with whether it is possible?

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and is particularly useful for connecting objects such as hanging objects in high temperature or corrosive atmospheres, or for transmitting power from the outside. Compared to conventional ceramic products, the structure is simpler and cheaper, and it is possible to manufacture chains with small to complex shapes, as well as chains that can be bent in all directions. An object of the present invention is to provide a chain and a method for manufacturing the same.

Means for Solving the Problems] That is, the first invention is a chain made of molded parts made of raw materials kneaded with powder materials such as ceramics and metals and a binder, and which is made of a green body that is degreased (removed from binders) and sintered. A ml part is formed by shrinking into a sintered body by sintering and has an engagement hole, and the green body is degreased and shrinked into a sintered body by sintering before the engagement hole shrinks. It is a chain-like chain configured by connecting a second part having an engagement protrusion that can be engaged with the engagement hole.

Further, the second invention provides a first component in which an engagement hole is formed;
and a step of molding a second part having an engagement protrusion that can be inserted into the engagement hole to make each green body, and degreasing the first part and the second part to make each a degreased body. a step of sintering the second component to shrink the second component into a sintered body; and a step of sintering the second component to form a sintered body, and removing the engaging protrusion of the sintered second component into a degreased body. 1st above
a step of inserting the parts into the engagement holes of the parts to form a combined body;
This combination is sintered to shrink the first part to form a sintered body, and the engaging hole of the first part is engaged with the engaging protrusion of the second part. A method for manufacturing a chain, comprising the step of connecting the first part and the second part together.

This will be explained in detail below. First, the basic principles of the present invention will be explained together with the production of molded parts from ceramic powder or metal powder.

For example, there are various methods for molding ceramics, but here we will specifically explain injection molding as an example.

In a chain manufacturing method based on ceramic injection molding, an organic material (wax, resin such as polyethylene) is added to the ceramic powder in a volume close to that of the ceramic powder.
By adding it as a binder, it gives fluidity to the raw material. Then, like plastic, it is filled into a mold using an injection molding machine and molded into an arbitrary part shape.

A molded body obtained by such a manufacturing method is called a green body. This green body is heated very slowly (1 to 7 days) and thermally decomposed (400 to 600°C) to remove only the binder, which is then used as a degreased body.

Next, when this degreased body is sintered at a high temperature (1500 to 1600°C), this 1! ! Fat body shrinks 10-25
%), the density increases to obtain the final sintered body.

This manufacturing method has made it possible to mass produce ceramic products with complex shapes, which was previously difficult.

Note that shrinkage does not occur from the green body to the degreased body, but a large amount of shrinkage occurs from the degreased body to the sintered body.

Further explanation will be given below based on FIGS. 1 to 7.

As shown in FIG. 1, a first part 10 and a second part 11 are formed as a green body by injection molding. Note that the shrinkage rate is adjusted by appropriately selecting the blending ratio of the ceramic powder or metal powder and the binder or the respective components.

The first component 10 has engagement holes 12 formed at its left and right ends, and an inner cavity 13 that communicates with the engagement holes 12. Further, the second component 11 is a shaft portion 14
It has an engaging protrusion 15 formed at its left and right ends. In the final product, the engagement hole 12 is inserted into and engaged with the engagement protrusion 15.

Note that FIG. 2 is a side view of the first component 10, and FIG. 3 is a perspective view of the first component 10.

Part 11 of 9Js2 in the green body state shown in Figure 1.
The outer diameter of the shaft portion 14 is k, the outer diameter of the engagement protrusion 15 is dg,
If the inner diameter of the engagement hole 12 of the first component 10 is Dg, and the inner diameter of the inner cavity 13 is Wg, the setting is made such that, for example, k < D g < d g < W g .

As shown in FIG. 4, when the first part 10 and the second part 11 are made into fat bodies by degreasing, the shrinkage is very slight, so the second part 1 after degreasing
If the outer diameter of the first engaging protrusion 15 is dd, and the outer diameter of the inner cavity 13 of the first component 10 is Dd, then dd=dg and Dd=Dg.

Next, only the second part 11 is sintered to form the sintered body shown in FIG. 5. As a result of this sintering, the second part 11 becomes 15 to 2
Shrinkage of about 5% occurs. Therefore, the engaging protrusion 15
If the outer diameter after sintering is ds, then ds<dd.

Note that ds<Dd The intended design shall be such that.

Next, the first part 10 that has been previously degreased to the state shown in FIG. 4 and the first part 10 after sintering are connected as shown in FIG. 6. That is, the engagement protrusion 15 is inserted into the inner space 13.
A combination body 16 is constructed by inserting the parts into the inside and combining them.

Such a combination 16 is installed on a shelf (not shown). Note that the length of one combination 16 can be arbitrarily selected. In some cases, the first and last parts may be connected to form a ring shape as a whole.

Next, this temporarily assembled assembly 16 is sintered together with the shelf board. The second part 11 has almost no shrinkage or dimensional change due to the second sintering, but the first part 10 has 15 to 25
% shrinkage.

Therefore, the engagement hole 12 of the first component 10 after sintering
If the inner diameter of is Ds, then Ds<ds.

Therefore, the first part 10 and the second part 11 are connected by the engagement between the engagement hole 12 and the engagement protrusion 15 and cannot be separated from each other, completing the connection and forming the chain 17 as a final product. be able to.

In the present invention, the above-mentioned relationship between the shrinkage rate and dimensions of the first part and the second part is set as appropriate depending on the chain to be manufactured.

Furthermore, the present invention is applicable not only to ceramics but also to metal powders. For example, it can be used to hang products in high-temperature furnaces, to transmit power, and to manufacture chains used for decorative items such as ceramic collars.

[Function] In the chain and its manufacturing method according to the present invention,
Since the sintering timing of the first part and the sintering time of the second part are shifted and the mutual engagement and connection are performed by contraction of the first part, the connection between the parts constituting the chain is improved. This is possible without using any special method, and therefore costs can be reduced. Additionally, the chain has greater flexibility than before. It is also possible to manufacture even thinner chains.

Note that if the material is ceramic, it is possible to manufacture products with superior heat resistance and corrosion resistance compared to metal products such as stainless steel or titanium.

Furthermore, if the parts are made of injection molded products, chains of various shapes can be manufactured efficiently.

[Example] Next, an example of a chain and a manufacturing method thereof according to the present invention will be described.

A chain-shaped molded article is molded by injection molding using kneaded raw materials having a composition of 60% by volume of zirconia as ceramic powder and 40% by volume of binder (organic material). A molded article with this composition does not undergo any dimensional change in the a resin process, but shrinks by 27% from its original size in the sintering process.

1 method each of the first part 10 and the second part 11 (unit:
mm) are set as shown in the table of FIG.

The engaging protrusion 15 of the second component 11 sintered earlier has a dg of 10 mm and a ds of 7. 3mm, and the Dg of the engagement hole 12 that did not fit in the green body (
8mm).

When the first part 10 and the second part 11 are sintered, the engagement hole 12 has a Dg of 8 mm and a Ds of 5 mm.
．． Shrinks to 84mm. Therefore, the engagement protrusion 15 of the second component 1F cannot be removed from the engagement hole 12 of the first component 10. Note that the second component 11 to be two-component sintered
dimensions do not change.

As a result, the connection of the first part 10 and the part 11 of 'ft52 is completed, and the chain 17 is obtained as a final product.

[Effects of the Invention] As described above, according to the present invention, the first part and the second part can be engaged and connected by utilizing the difference in shrinkage rate between the sintered body and the degreased body. Chains can be manufactured without using special methods, costs can be reduced, and chains with complex shapes can also be manufactured according to requirements.

[Brief explanation of drawings]

1 to 8 illustrate the method of manufacturing a chain according to the present invention. FIG. 1 is a sectional view of the first part 10 and a side view of the second part 11 in a green body state. FIG. 2 is a side view of the first component 10, and FIG. 3 is a perspective view of the first component 10. FIG. 4 is a sectional view of the first component 10 in the state of a fat body and a side view of the second component 11, and FIG. 5 is a side view of the second component 1 in the state of a sintered body. FIG. 6 is a sectional view of a combination 16 of the first component 10 in a degreased state and the second component 11 in a sintered state. FIG. 7 is a sectional view of the final product (chain 17) obtained by sintering the first part 1 and the second part 11, and FIG. 8 is a table of dimensions in one embodiment of the present invention. FIG. 9 is a perspective view of a conventional chain 1, and FIG. 10 is a perspective view of a conventional chain 2. 1.20. Chain 3.40. Element 10 , First part 11 , Second part 12 . , Engagement hole 13 , Inner cavity 14 , I) 11 section 15 , Engagement protrusion 16 , Combination 17 , , , , Chain (M finished product) k , , ,
,,outer diameter dg of the shaft portion 14 in the state of a green body, .
Outer diameter D g of the engagement protrusion 15 in the green body state, ..., the engagement hole in the green body state! 12
The inner diameter Wg, the inner diameter dd of the inner cavity 13 in the state of the green body,
, the outer diameter Dd of the engagement protrusion 15 in the degreased state, the outer diameter ds of the inner cavity 13 in the degreased state, , the outer diameter Ds of the engagement protrusion 15 in the sintered state ,, Inner diameter of the engagement hole 12 in the state of a sintered body Patent applicant: Sumitomo Heavy Industries, Ltd.

Claims (2)

[Claims] (1) A chain made of molded parts made of raw materials kneaded with a powder material and a binder, which is formed by shrinking a green body into a sintered body through degreasing and sintering, and a first part having an engagement hole. and a second part that shrinks the green body into a sintered body by degreasing and sintering before the contraction of the six engagement parts, and has an engagement protrusion that can be engaged with the engagement hole. A chain made up of connections. (2) molding a first component having an engagement hole and a second component having an engagement protrusion that can be inserted into the engagement hole into green bodies; a step of degreasing the first part and the second part to form degreased bodies, a step of sintering the second part to shrink the second part to form a sintered body; inserting the engaging protrusion of the second component into the engaging hole of the first component in a degreased state to form an assembled body; and sintering this assembled body to form the first component. is contracted to form a sintered body, and the engaging hole portion of the first component and the engaging protrusion of the second component are engaged to connect the first component and the second component. A method for manufacturing a chain, comprising the step of connecting.