JPH0726070Y2 - Rubber mold for hydrostatic molding - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a hydrostatic molding rubber mold used for obtaining a powder compact such as hydroxyapatite.

[Conventional technology]

Hydroxyapatite has attracted attention as various biomedical members because of its excellent biocompatibility. An example of this type of hydroxyapatite member is a skin terminal. The skin terminal is a member used by partially embedding it in the living body to connect the inside and outside of the living body, and as shown in FIG. 12, a catheter is provided outside the skin terminal 51 partially embedded in the living body 50. The silicone tube 53, which is connected to 52 and is connected to the inner side, is connected to a blood vessel (not shown) for blood vessel injection, or for connection peritoneal dialysis.

Such a skin terminal is manufactured as follows, for example. Granules of hydroxyapatite are preformed by a pressing machine into a coarse granule compact, and then the granule compact is placed in a rubber bag having no bottomed cylindrical shape. The rubber bag containing the granule compact inside is placed in a vacuum desiccator and evacuated, then the opening is clamped with a wire rod in the vacuum desiccator, taken out from the vacuum desiccator, and then the opening is closed with a rubber band or the like. The wire is put back in the vacuum desiccator after being tightly closed and airtightly closed. The rubber bag containing the granule compact is subjected to hydrostatic pressure molding (CIP molding) to mold the granule compact into a cylindrical green compact.

Then, with one end of the green compact held by a holder, mechanical processing such as turning with a bite is performed to form a predetermined skin terminal shape, and then sintered to obtain a product. Eggplant

[Problems to be solved by the device]

However, in the case of such a conventional rubber bag used for molding a green compact, in order to evacuate the rubber bag, it is necessary to take the rubber bag containing the granule compact into and out of the vacuum device, The work of airtightly closing the opening after the work of (2) is troublesome because of double labor, and the work efficiency is poor, and the durability is poor because it is made of a relatively thin rubber. In addition, in the case of the conventional powder compact of hydroxyapatite, the whole body is formed by the granule molded body, so when applying machining such as turning to the skin terminal shape, for example, one end of the powder compact However, if the holder is firmly held by the holder, the held portion may be cracked, resulting in a defect in the machined skin terminal.

[Means for Solving the Problems]

The present invention has been made in view of such a conventional technical problem, and the structure of the invention according to claim (1) is such that a relative rotation of a granulated body and a protrusion on the granulated body is not possible. What is claimed is: 1. A hydrostatic rubber mold for covering the granule compact of a preformed member composed of a metal holding member that is embedded as much as possible, and has a large diameter that elastically adheres to the outer periphery of the holding member. A rubber mold for hydrostatic molding having a tubular portion and a small-diameter tubular portion connected to a vacuum device and closed by a stopper after evacuation.

[Action]

Therefore, according to the rubber mold for hydrostatic molding of claim (1), the preformed member preformed by press molding is put into the rubber mold and subjected to hydrostatic molding. That is,
Insert a preformed member consisting of a granular molded body such as hydroxyapatite and a holding member from the granular molded body side into the large diameter tubular portion of the rubber mold, and the end of the large diameter tubular portion is the outer periphery of the holding member. Elastically adheres to, keeps airtight and liquid-tight, the inside is sufficiently depressurized when vacuuming, and at the time of hydrostatic molding,
This prevents water from entering the inside of the holding member in the initial stage until a predetermined pressure is applied and the large-diameter tubular portion comes into close contact with the outer periphery of the holding member. Next, the small-diameter tubular portion of the rubber mold is connected to a vacuum device and vacuumed to eliminate air inside the rubber mold, that is, around the preformed granule compact. After that, the base end portion of the small-diameter tubular portion is sandwiched by a tool such as a nipper to prevent air from entering the inside, and the small-diameter tubular portion is hermetically closed by a stopper.

In this way, the preformed member in which the granule molded body portion is covered with the rubber mold is subjected to hydrostatic molding. By the hydrostatic molding, a granular molded body is molded into a powder compact, and a powder compact member in which a metal holding member is fixed to one end of the powder compact is manufactured. The dust member is machined into a skin terminal, for example. At that time, while the holding member is held by the holding tool, it is processed with a bite or the like to manufacture a processed product of the skin terminal. The processed product of this skin terminal is sintered into a product skin terminal.

As described above, since the metal powder holding member holds the metal holding member by the holder during machining with a cutting tool or the like, a crack such as a crack is generated in the green compact with firm and reliable holding. There is no fear of it.

〔Example〕

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

1 to 11 show an embodiment in which the present invention is applied to a rubber mold for a preformed member of a skin terminal. Reference numeral 1 in FIG.
Indicates a main part of the pressing device, in which the lower piston member 3 and an annular contact plate 4 made of silicone rubber are placed on the bolster 2, and the cylinder member 5 on which the upper part of the lower piston member 3 is fitted and inserted. To place. The lower piston member 3 is the third
As shown in detail in FIGS. 1A and 1B, a first piston member 3a having a shape in which a small-diameter cylindrical portion 3d is provided at the center of a large-diameter cylindrical portion 3c.
And a second piston member 3b that forms an annular body that fits into the small-diameter cylindrical portion 3d of the first piston member 3a, and that has an upper inner peripheral surface that forms a curved surface that gradually increases in diameter upward.

Hydroxyapatite granules 6 (3
An appropriate amount of a binder (containing 9% to 9%) is charged, a metal holding member 7 is fitted thereon, and the ram 8 pressurizes the holding member 7. As shown in FIG. 4, the holding member 7 has a shape in which a threaded portion 7b, which is a protruding portion, projects from one end of a cylindrical holding member body 7a, and is made of metal such as steel. . In such a holding member 7, the screw portion 7b is placed on the granule 6 with the hydroxyapatite granule 6 side, that is, the lower side, and a pressure of about 200 kgf / cm ² is applied by the ram 8. Then, the lower piston member 3 is released from the mold, and the cylinder member 5 is demolded and removed. Then, as shown in FIG. 1, the threaded portion 7b of the holding member 7 is provided in the cylindrical granular preform 6a.
A preformed member 9 is obtained by embedding and integrating. The end of the preformed granule compact 6a has the first piston member 3a.
And the second piston member 3b to form a mountain shape with a raised central portion.

Such preformed member 9 is put into a rubber mold 10 as shown in FIG. 1 and subjected to isostatic pressing (CIP molding). Rubber mold 1
Reference numeral 0 denotes a large-diameter cylindrical portion that receives the granule compact 6a and elastically adheres to the outer periphery of the holding member 7 as shown in FIG.
10a and a through hole 10c connected to the vacuum device 25 shown in FIG. 7 and closed by a stopper 13 having a plug shape after evacuation.
And a small-diameter tubular portion 10b having an inner surface between the large-diameter tubular portion 10a and the small-diameter tubular portion 10b has a preformed granular molded body 6a.
It has a chevron shape that matches the edges of the. The stopper 13 is
As shown in FIG. 6, it has a shaft portion in which a large diameter portion and a small diameter portion are alternately formed, and grips a knob portion 13a at one end so that it can be elastically inserted into the small diameter cylindrical portion 10b of the rubber mold 10. It has become.

When the preforming member 9 is put into the rubber mold 10 and subjected to hydrostatic pressing, the hydroxyapatite granules 6 are applied to one end of the green compact 11a formed into a relatively solid columnar shape as shown in FIG. , A powder member 11 for a skin terminal to which a metal holding member 7 is fixed
Is produced. In the holding member 7, the screw portion 7b has the green compact 11a.
And the holding member main body 7a projects from the green compact 11a. Thus, the holding member 7 is constrained from relative rotation in one direction in which the screw portion 7b is tightened with respect to the green compact 11a.

Next, the operation will be described.

The preformed member 9 preformed between the lower piston member 3 and the ram 8 of the pressing device is put into the rubber mold 10 and subjected to hydrostatic molding. That is, the preforming member 9 is inserted into the large-diameter cylindrical portion 10a of the rubber mold 10 from the side of the granule molding 6a, and the open end of the large-diameter cylindrical portion 10a is elastically adhered to the outer periphery of the holding member 7. Let The inside of the rubber mold 10 is sufficiently depressurized during evacuation, and during hydrostatic molding, a predetermined pressure is applied and the large-diameter cylindrical portion 10a is brought into close contact with the outer periphery of the holding member 7 in the initial stage. , A function to prevent water from entering inside is required. Therefore, as shown in FIGS. 1 and 7, the end of the large-diameter cylindrical portion 10a is elastically fastened to the holding member 7 by the rubber O-ring 26 to ensure airtightness and liquid-tightness. You can Next, the small-diameter tubular portion 10b of the rubber mold 10
Is connected to a vacuum device 25 and a vacuum is drawn to eliminate the air inside the rubber mold 10, that is, around the preformed granule compact 6a.
After that, the base end of the small-diameter tubular portion 10b is sandwiched by a tool such as a nipper to prevent air from entering the inside, and the stopper 13 is elastically press-fitted into the small-diameter tubular portion 10b to be airtight and liquid-tight. To block.

In this way, the preformed member 9 covering the portion of the granule compact 6a with the rubber mold 10 is subjected to hydrostatic molding. The hydrostatic molding is performed by applying a pressure of about 3500 kgf / cm ² to the entire outer surface, and as shown in FIG. 8, the hydroxyapatite granules 6 are molded into a relatively solid cylindrical green compact 11a, This green compact 11a
A powder member 11 for a skin terminal having a metal holding member 7 fixed to one end thereof is manufactured.

The powder member 11 for the skin terminal has a through hole at the center shown in FIG. 10 in a state where the holding member main body 7a of the holding member 7 is held by the holding tool 12 as shown in FIG. 16 and a large-diameter flange portion 17 to be described later are provided with a plurality of through holes 18 formed at equal intervals in the circumferential direction, and then turned by a cutting tool 14, and as shown in FIG. The flange portion 19 and the large-diameter flange portion 17 on the base end side are formed. The tip of the green compact 11a is
Since the central portion has a chevron shape and the diameter is gradually reduced toward the tip, the small-diameter flange portion 19 can be formed by slight turning. When the powder compact 11 is rotated for machining, the screw 7b is rotated in the direction in which the powder compact 11a is tightened by the resistance associated with the machining so that the holding member 7 and the powder compact Prevents relative rotation with 11.

As described above, since the metal holding member 7 is held by the holding tool 12 during machining with the cutting tool 14 or the like, the dust member 11 for the skin terminal is firmly and surely held.
There is no fear that the green compact 11a made of hydroxyapatite will have defects such as cracks. As a result, the processed product 15 of the skin terminal having no defect and good quality is manufactured.

Then, the machined powder member 11 is cut along a line AA shown in FIG. 9 by a cut-off tool or the like, so that both sides of the short tubular portion 20 are cut as shown in FIGS. A processed product 15 of the skin terminal having a pair of flange portions 17 and 19 is manufactured. The processed product 15 of the skin terminal is sintered into a product skin terminal.

The present invention can be applied not only to hydroxyapatite skin terminals, but also to artificial tooth roots and the like, as well as rubber for hydrostatic molding of preformed members in which a metal holding member is widely embedded in a granular molded body. Can be applied to molds.

[Effect of device]

As can be understood from the above description, according to the rubber mold for hydrostatic molding according to the present invention, the small-diameter cylindrical portion which is connected to the vacuum device and closed by the stopper after evacuation is formed. Since the rubber mold can be evacuated without putting it in and out of the desiccator of the vacuum device, and the vacuum-sealing work can be performed outside the vacuum device by closing the small-diameter cylindrical portion with the stopper. , Its work efficiency is good. Furthermore, since the small-diameter tubular portion, that is, the small-diameter through-hole is closed, vacuum sealing is easy even if the entire hydrostatic molding rubber die is formed thick. As a result, the durability of the rubber mold for hydrostatic molding is significantly improved. In addition, the preforming member is provided with a metal holding member, and after hydrostatic forming, this holding member can be held and machined by a holding tool, so that the green compact is less likely to be damaged, Good processed products can be manufactured.

[Brief description of drawings]

1 to 11 show one embodiment of the present invention, FIG. 1 is a sectional view showing a rubber mold in a hydrostatic molding step, FIG. 2 is a sectional view showing a pressing step, and FIG. 3 (a) is FIG. 3 is a perspective view showing a first piston member, FIG. 3 (B) is a sectional view showing a second piston member, FIG. 4 is a perspective view showing a holding member, FIG. 5 is a sectional view showing a rubber mold, and FIG. The figure shows a stopper, FIG. 7 is a partial cross-sectional view showing a vacuuming process, FIG. 8 is a partial cross-sectional view showing a machining process, and FIG. 9 is a dusting member in which machining has progressed. FIG. 10 is a front view showing a processed product of the skin terminal,
FIG. 11 is a side view showing a processed product of the skin terminal, and FIG. 12 is an explanatory view showing an example of using the skin terminal. 6: Hydroxyapatite granules, 6a: Granule compact, 7: Holding member,
7a: Holding member main body, 7b: Screw part (projection part), 9: Preformed member, 10, 21: Rubber mold, 10a: Large diameter tubular part, 10b: Small diameter tubular part, 10c:
Through hole, 11: Dust member, 11a: Dust powder, 13: Stopper, 13a: Knob, 25: Vacuum device.

Claims (1)

[Scope of utility model registration request] 1. A hydrostatic pressure of a preformed member comprising a granular molded body and a metal holding member integrally formed by embedding a projection in the granular molded body so as not to rotate relative to the granular molded body. A rubber mold for molding, comprising a large-diameter tubular portion elastically adhered to the outer periphery of the holding member, and a small-diameter tubular portion connected to a vacuum device and closed by a stopper after evacuation. A rubber mold for hydrostatic molding characterized by having.