Powder Compression Molding Device

Abstract

To provide a powder pressure forming apparatus having good pressure performance and durability. 【Solution means】The powder pressure forming apparatus includes a pressure cylinder 52 having curved surfaces with a central angle of 180° or more at both axial ends, and a pressure elastic cylinder 62 that is in close contact with the inner diameter side of the pressure cylinder 52 and is wound so that the central angle becomes 180° or more at both ends to form a winding portion 63, and is also in close contact with the outer diameter side of the elastic cylinder 64. The hardness of the elastic cylinder 64 is higher than that of the pressure elastic cylinder 62, and the radius of curvature of the curved surface of the pressure cylinder 52 is equal to the thickness of the pressure elastic cylinder 62. Since a part of the end face and / or the winding portion 63 of the pressure elastic cylinder 62 is exposed in the pressure liquid inflow space, when the pressure liquid is supplied from the pressure liquid supply / discharge port, the pressure from the pressure liquid is easily transmitted to the elastic cylinder 64, and each component is difficult to be damaged.

Description

Technical Field

[0001] The present invention relates to a powder pressure molding apparatus (hereinafter sometimes simply referred to as "powder pressure molding apparatus") used for dry rubber pressing (hydrostatic molding) of powders.

Background Art

[0002] In dry rubber pressing, a rubber mold is previously incorporated into a high-pressure vessel, and the rubber mold is pressed with a liquid such as oil or glycerin while maintaining a constant axial length. Therefore, it is suitable for mass production, but it is said to have a drawback that it cannot be pressed from the entire circumference of the non-pressurized body. Isao Matsushita, the inventor of the present invention, has made many improvements to the powder pressure molding apparatus used for the dry rubber pressing having the above-described properties. For example, there are the following.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a powder pressure molding apparatus including a pressure cylinder having elasticity and flexibility, a holding case externally fitted to the pressure cylinder, and a pressure liquid supply port opened at a portion of a pressure liquid guide surface facing an initial pressure application region of the pressure cylinder. By making the external fitting in an interference fit state, the outer peripheral surface of the pressure cylinder is pressed against the pressure liquid guide surface. According to this, a concave groove and an elastic seal ring are not required for the pressure cylinder.

[0005] Patent Document 2 discloses a powder pressure molding apparatus including a pressurizing cylinder having elasticity and flexibility, a holding case that externally fits over the pressurizing cylinder and has an inner surface for guiding a pressurized liquid as an externally fitted inner surface, and a pressurized liquid supply port formed at a portion of the inner surface for guiding a pressurized liquid that faces an initial pressurization region of the pressurizing cylinder. By mounting the pressurizing cylinder in a state where it is axially compressed in the holding case, the outer peripheral surface of the pressurizing cylinder is pressed against the inner surface for guiding a pressurized liquid. According to this, it is said that initial pressurization can be reliably performed using a liquid at a higher pressure than before.

[0006] By the way, for a powder pressure molding apparatus, a pressurization performance capable of favorably pressurizing powder even with a liquid at a relatively low pressure, and a durability in which components are not damaged even with a liquid at a relatively high pressure, that is, a long life for coping with mass production over a long period of time are required, and there is still room for improvement in these aspects.

[0007] Therefore, an object of the present invention is to provide a powder pressure molding apparatus having both good pressurization performance and durability in view of the above points.

Means for Solving the Problems

[0008] The present invention includes an elastic cylinder having a powder storage space on the inner diameter side, a pressurizing cylinder that externally fits over the elastic cylinder, has a through hole penetrating in the radial direction, and has curved surfaces with a central angle of 180° or more at both axial ends, a pressurizing elastic cylinder that is in close contact with the inner diameter side of the pressurizing cylinder, is provided so as to be wound at both ends so that the central angle becomes 180° or more to form a wound portion, and is also in close contact with the outer diameter side of the elastic cylinder, a holding case that externally fits over the pressurizing cylinder, forms a sealed pressurized liquid inflow space between the holding case and the pressurizing cylinder, and has a pressurized liquid supply / discharge port penetrating in the radial direction, a powder storage space axial pressurizing member that pressurizes the powder storage space from both axial sides inward, In a powder pressure molding apparatus including a pressurizing member that pressurizes the elastic cylinder from both axial sides inward within a range where the central angle of the wound portion is 180°, The hardness of the elastic cylinder is higher than that of the pressurized elastic cylinder, the radius of curvature of the curved surface is equal to the thickness of the pressurized elastic cylinder, and a part of the end face of the pressurized elastic cylinder and / or the wound part is exposed in the pressurized liquid inflow space, which solves the above problems in the powder pressurizing and molding apparatus.

Advantages of the Invention

[0009] According to the present invention, an elastic cylinder having a powder storage space on the inner diameter side, a pressurizing cylinder that is externally fitted to the elastic cylinder, has a through hole penetrating in the radial direction, and has curved surfaces with a central angle of 180° or more at both axial ends, a pressurized elastic cylinder that is in close contact with the inner diameter side of the pressurizing cylinder and is wound so that the central angle becomes 180° or more at both ends to form a wound part, and is also in close contact with the outer diameter side of the elastic cylinder, a holding case that is externally fitted to the pressurizing cylinder, forms a sealed pressurized liquid inflow space between the holding case and the pressurizing cylinder, and has a pressurized liquid supply / discharge port penetrating in the radial direction, a powder storage space axial pressurizing member that pressurizes the powder storage space from both axial sides to the inside, and a pressurizing member that pressurizes the wound part within a range where the central angle is 180° and the elastic cylinder from both axial sides to the inside in a powder pressurizing and molding apparatus, the hardness of the elastic cylinder is higher than that of the pressurized elastic cylinder, the radius of curvature of the curved surface of the pressurizing cylinder is equal to the thickness of the pressurized elastic cylinder, and a part of the end face of the pressurized elastic cylinder and / or the wound part is exposed in the pressurized liquid inflow space. Therefore, when pressurized liquid is supplied from the pressurized liquid supply / discharge port, the pressure from the pressurized liquid is transmitted from the through hole to the pressurized elastic cylinder and is also transmitted to a part of the end face of the pressurized elastic cylinder and / or the wound part exposed in the pressurized liquid inflow space, resulting in pressurization in the axial outer direction. Here, since the wound part of the pressurized elastic cylinder is pressurized from both axial sides to the inside by the wound part pressurizing member, the axial pressurization of the pressurized elastic cylinder is canceled, and pressurization in the radial inner direction is more likely to be applied. As a result, even with a liquid at a relatively low pressure, the powder can be well pressurized, and even with a liquid at a relatively high pressure, each component such as the pressurized elastic cylinder is less likely to be damaged. Therefore, a powder pressurizing and molding apparatus having good pressurizing performance and durability can be provided.

[0010] In addition, if the pressure cylinder has a wall thickness portion that occupies at least a part of the pressurized liquid inflow space, the amount of pressurized liquid used during pressurization can be reduced.

[0011] In addition, if at least one of the powder storage space axial pressure members is configured to absorb the force to the outside in the axial direction when the pressurization from both sides in the axial direction to the inside is released, the die expansion of the powder generated when the pressure on the powder is released can be absorbed, and the pressurized powder can be easily taken out from the powder pressure molding apparatus.

Brief Description of Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. However, the present invention is not limited to this embodiment.

[0014] As shown in FIG. 1, the powder pressure molding apparatus 100 has a cylindrical holding case 10. One or more pressurized liquid supply / discharge ports 12 that penetrate in the radial direction from the outer diameter side to the inner diameter side are provided in the holding case 10. The holding case 10 may be formed of a high-strength material (for example, carbon steel or the like). In addition, as the pressurized liquid supplied and discharged from the pressurized liquid supply / discharge port 12, oil, glycerin, boric acid water, or the like may be used.

[0015] In the space on the inner diameter side of the holding case 10, a cylindrical pressure cylinder 52 is disposed. That is, the holding case 10 is externally fitted to the pressure cylinder 52. As shown in FIG. 2, the pressure cylinder 52 is provided with one or more through holes 56 penetrating in the radial direction from the outer diameter side to the inner diameter side. Further, curved surfaces with a central angle of 180° or more are formed at both axial ends (both ends) 54 of the pressure cylinder 52. The pressure cylinder 52 is formed of a high-strength material (for example, carbon steel or the like).

[0016] On the inner diameter side of the pressure cylinder 52, a cylindrical pressure elastic cylinder 62 is disposed. The pressure elastic cylinder 62 is in close contact with the inner diameter side of the pressure cylinder 52 and is mounted on the pressure cylinder 52 so as to be wound at both ends 54 of the pressure cylinder 52 so that the central angle becomes 180° or more to form a wound portion 63. The thickness of the pressure elastic cylinder 62 is set to be equal to the radius of curvature of the curved surfaces at both axial ends of the pressure cylinder 52. The pressure elastic cylinder 62 is formed of an elastic and flexible material (for example, neoprene rubber, urethane resin, etc.).

[0017] On the inner diameter side of the pressure elastic cylinder 62, a cylindrical elastic cylinder 64 is disposed (see FIG. 1). That is, the pressure cylinder 52 is externally fitted to the elastic cylinder 64. Further, the outer diameter side of the elastic cylinder 64 is defined so as to be in close contact with the pressure elastic cylinder 62, and the diameters of the elastic cylinder 64 and the pressure elastic cylinder 62 are respectively determined. The inner diameter side of the elastic cylinder 64 becomes the powder storage space 48. The elastic cylinder 64 is formed of an elastic and flexible material (for example, neoprene rubber, urethane resin, etc.). Here, the hardness of the elastic cylinder 64 is higher than that of the pressure elastic cylinder 62. Also, the thickness of the elastic cylinder 64 is preferably thicker than that of the pressure elastic cylinder 62.

[0018] The powder 44 to be pressurized is accommodated in the powder storage space 48. When obtaining a hollow molded product, a mandrel 46 may be disposed as shown in the figure, and when obtaining a solid molded product, the mandrel 46 may be omitted. Lid portions 42 are respectively disposed on both sides in the axial direction of the pressure cylinder 52 with respect to the powder 44. As a result, the powder 44 is filled in the powder storage space 48 between the inner diameter side of the elastic cylinder 64 and the pair of lid portions 42.

[0019] The central angle of the winding portion 63 of the pressurized elastic cylinder 62 in the range of 180° and the elastic cylinder 64 are configured to be in contact with a pair of annular pressurizing members 24, 34. And, as will be described later, pressures from both axial sides of the pressurizing cylinder 52 toward the inside are applied to the pressurizing members 24, 34. Thus, the central angle of the winding portion 63 of the pressurized elastic cylinder 62 in the range of 180° and the elastic cylinder 64 are respectively pressurized from both axial sides of the pressurizing cylinder 52 toward the inside. Although detailed illustration is omitted, between the pressurizing members 24, 34 and the holding case 10, seal rings (not shown) and the like are respectively provided to be sealed. Thereby, a sealed pressurized liquid inflow space 14 is formed between the holding case 10 and the pressurizing cylinder 52. In the pressurized liquid inflow space 14, the end face of the pressurized elastic cylinder 62 and, when the winding portion 63 is provided with a central angle exceeding 180°, a part of the winding portion 63 will be exposed.

[0020] Also, the powder storage space 48 is respectively pressurized from both axial sides of the pressurizing cylinder 52 toward the inside by a pair of powder storage space axial pressurizing members 22, 32. The powder storage space axial pressurizing member 22 is screwed into the holding case 10 and presses one side lid portion 42. At this time, since the powder storage space axial pressurizing member 22 is also in contact with the pressurizing member 24, the pressurizing member 24 is also pressed.

[0021] On one hand, the powder storage space axial pressure member 32 is in contact with the lid portion 42 on the other side, and is in contact with the pressure member 34 via the kinetic energy absorption member 36 provided in the powder storage space axial pressure member 32. Here, by screwing the pressure case 38 engaged with the powder storage space axial pressure member 32 to the holding case 10, the lid portion 42 on the other side and the pressure member 34 are pressed. The kinetic energy absorption member 36 is a cylinder having an elastic member such as a spring, and is configured to bias the powder storage space axial pressure member 32 in the direction opposite to the powder storage space 48. Further, the pressure case 38 is provided with a cylinder pressure liquid supply / discharge port 35 for supplying and discharging the pressure liquid to / from the sealed space between the powder storage space axial pressure member 32. When the pressure liquid is supplied to the sealed space between the powder storage space axial pressure member 32 through the cylinder pressure liquid supply / discharge port 35, the powder storage space axial pressure member 32 compresses the cylinder of the kinetic energy absorption member 36 and moves in the direction of the powder storage space 48. That is, when the pressure from both sides in the axial direction to the inside is released, the powder storage space axial pressure member 32 can absorb the force to the outside in the axial direction. Note that as the pressure liquid supplied and discharged from the cylinder pressure liquid supply / discharge port 35, oil, glycerin, boric acid water, etc. may be used.

[0022] When the pressure liquid is supplied to the pressure liquid inflow space 14 through the pressure liquid supply / discharge port 12, as shown in FIG. 2, the pressure liquid passes through the through hole 56 and pressurizes the pressure elastic cylinder body 62, and also pressurizes the pressure elastic cylinder body 62 from a part of the end face and / or the winding portion 63 of the pressure elastic cylinder body 62. On the other hand, the pressure elastic cylinder body 62 is pressurized from both sides in the axial direction of the pressure cylinder body 52 to the inside by the pressure members 24, 34. Here, the pressure by the pressure members 24, 34 is transmitted to the winding portion 63 of the pressure elastic cylinder body 62, but the pressure from the pressure liquid is also transmitted to the winding portion 63 from a part of the end face and / or the winding portion 63 of the pressure elastic cylinder body 62. Therefore, the pressure applied to the pressure elastic cylinder body 62 from the pressure liquid is difficult to escape from the winding portion 63 and is easily transmitted to the elastic cylinder body 64. That is, since the pressure from the pressure liquid is easily transmitted from the elastic cylinder body 64 to the powder 44, a powder pressure forming apparatus 100 having good pressure performance can be obtained.

[0023] Further, since the pressure from the pressing members 24 and 34 cancels out the pressure from the pressurizing liquid at both ends of the pressurizing elastic cylinder 62, deformation and breakage of the pressurizing elastic cylinder 62 to which the pressure from the pressurizing liquid is directly applied can be prevented. Therefore, the powder pressure molding apparatus 100 has high durability.

[0024] Here, a configuration may be adopted in which a thick-walled portion 58 that occupies at least a part of the pressurizing liquid inflow space 14 is provided, such as the pressurizing cylinder 52 of the powder pressure molding apparatus 100. With this configuration, the amount of pressurizing liquid used during pressurization can be reduced.

[0025] Further, like the powder storage space axial direction pressing member 32 of the powder pressure molding apparatus 100, if at least one of the powder storage space axial direction pressing members 22 and 32 is configured to absorb the force in the axial direction outward when the pressurization from both sides in the axial direction to the inside is released, the mold release expansion of the powder 44 that occurs when the pressurization of the powder 44 is released can be absorbed, and the pressurized powder 44 can be easily taken out from the powder pressure molding apparatus 100.

[0026] FIG. 3 is a longitudinal sectional view of a powder pressure molding apparatus 100a according to a second embodiment of the present invention. Since the basic configuration is the same as that of the powder pressure molding apparatus 100, the same reference numerals are given to the same members and the description thereof is omitted, and the differences will be described below.

[0027] In the powder pressure molding apparatus 100a, a pair of powder storage space axial direction pressing members 22a and 32a are configured to be screwed into the holding case 10a, and the powder storage space 48a is pressurized from both sides in the axial direction of the pressurizing cylinder 52a to the inside by the powder storage space axial direction pressing members 22a and 32a.

[0028] Between the powder storage space axial pressure members 22a and 32a and the powder storage space 48a respectively, kinetic energy absorption members 26a and 36a are provided. The kinetic energy absorption members 26a and 36a are formed of elastic members such as rubber, and are configured to absorb the force in the axial direction outward when the pressure from both sides in the axial direction of the pressure cylinder 52a is released inward. Therefore, also with this configuration, it is possible to absorb the mold release expansion of the powder that occurs when the pressure on the powder stored in the powder storage space 48a is released, and the pressurized powder can be easily taken out from the powder pressure molding apparatus 100a.

[0029] FIG. 4 shows a rubber mold 70 that can be stored in the powder storage spaces 48 and 48a. A pair of lid portions 42a are disposed on both sides in the axial direction of a pressure cylinder (not shown) of the rubber mold 70. The rubber mold 70 is composed of a plurality of rubber mold members 72a to 72f, and the spherical space formed inside thereof is filled with powder 44a. Therefore, according to the rubber mold 70, a spherical molded product can be obtained. In addition to this, by changing the shape of the rubber mold, molded products of various shapes can be obtained.

[0030] As described above, according to the present invention, it is possible to provide a powder pressure molding apparatus having both good pressure performance and durability.

Explanation of Reference Numerals

[0031] 10 Holding case 12 Pressure liquid supply / discharge port 14 Pressure liquid inflow space 22, 32 Powder storage space axial pressure members 24, 34 Pressure members 48 Powder storage space 52 Pressure cylinder 54 End 56 Through hole 58 Thickness portion 62 Pressure elastic cylinder 63 Winding portion 64 Elastic cylinder 100 Powder pressure molding apparatus

Claims

1. An elastic cylindrical body having a powder storage space on the inner diameter side, A pressurizing cylindrical body that is externally fitted to the elastic cylindrical body, has a through-hole that penetrates in the radial direction, and has curved surfaces with a central angle of 180° or more at both axial ends, A pressurizing elastic cylindrical body that is in close contact with the inner diameter side of the pressurizing cylindrical body, is wound so that the central angle becomes 180° or more at both ends to form a wound portion, and is also in close contact with the outer diameter side of the elastic cylindrical body, A holding case that is externally fitted to the pressurizing cylindrical body, forms a sealed pressurized liquid inflow space between the holding case and the pressurizing cylindrical body, and has a pressurized liquid supply / discharge port that penetrates in the radial direction, A powder storage space axial pressurizing member that pressurizes the powder storage space inward from both sides in the axial direction, In a powder pressurizing and forming apparatus having a pressurizing member that pressurizes the central angle of the wound portion within a range of 180° and the elastic cylindrical body inward from both sides in the axial direction, The hardness of the elastic cylindrical body is higher than that of the pressurizing elastic cylindrical body, The radius of curvature of the curved surface is equal to the thickness of the pressurizing elastic cylindrical body, The end face of the pressurizing elastic cylindrical body and / or a part of the wound portion are exposed in the pressurized liquid inflow space, characterized in that, Powder pressurizing and forming apparatus.

2. The powder pressurizing and forming apparatus according to Claim 1, wherein the pressurizing cylindrical body has a wall thickness portion that occupies at least a part of the pressurized liquid inflow space.

3. The powder pressurizing and forming apparatus according to Claim 1 or 2, wherein at least one of the powder storage space axial pressurizing members is configured to absorb an outward force in the axial direction when the pressurization inward from both sides in the axial direction is released.

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