Powder pressure molding apparatus

Abstract

To provide a powder pressure molding apparatus that combines excellent pressurization performance and durability. [Solution] The powder pressure molding apparatus comprises 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 curved at both ends to form a curved portion 63 with a central angle of 180° or more, 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, the radius of the curve of the curved surface of the pressure cylinder 52 is equal to the thickness of the pressure elastic cylinder 62, and the end faces of the pressure elastic cylinder 62 and / or a part of the curved portion 63 are exposed in the pressurized liquid inlet space, so when pressurized liquid is supplied from the pressurized liquid inlet and outlet, the pressure from the pressurized liquid is easily transmitted to the elastic cylinder 64, and each component is less likely 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-method rubber pressing (hydrostatic molding) of powder.

Background Art

[0002] In dry-method rubber pressing, a rubber mold is previously incorporated in 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-method rubber press having the above-described properties. For example, there are those listed below.

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 pressurizing cylinder having elasticity and flexibility, a holding case externally fitted to the pressurizing cylinder, and a pressurizing liquid supply port opened at a portion of a pressurizing liquid guide surface facing an initial pressurizing region of the pressurizing cylinder. By making the external fitting in an interference fit state, the outer peripheral surface of the pressurizing cylinder is pressed against the pressurizing liquid guide surface. According to this, a concave groove and an elastic seal ring are not required for the pressurizing cylinder.

[0005] Patent Document 2 discloses a powder pressure molding apparatus comprising an elastic and flexible pressure cylinder, a holding case that fits the pressure cylinder and whose inner surface serves as a pressure liquid guide surface, and a pressure liquid supply port opened in the portion of the pressure liquid guide surface facing the initial pressure region of the pressure cylinder. By mounting the pressure cylinder in the holding case in a state of axial compression, the outer surface of the pressure cylinder is pressed against the pressure liquid guide surface. According to this apparatus, initial pressure can be reliably performed using a liquid at a higher pressure than before.

[0006] By the way, powder pressure molding equipment requires pressurizing performance that can effectively pressurize powder even with relatively low-pressure liquids, durability that prevents damage to individual components even with relatively high-pressure liquids, and a long lifespan to support long-term mass production. There is still room for improvement in these aspects.

[0007] Therefore, in view of the above-mentioned points, the object of the present invention is to provide a powder pressure molding apparatus that combines good pressurization performance and durability. [Means for solving the problem]

[0008] The present invention comprises an elastic cylindrical body having a powder storage space on its inner diameter side, A pressurized cylinder is fitted onto the elastic cylinder, has a through hole that penetrates radially, and has curved surfaces with a central angle of 180° or more at both ends in the axial direction, A pressurized elastic cylinder is provided that is in close contact with the inner diameter side of the pressurized cylinder, and is bent at both ends so that the central angle is 180° or more to form a bent portion, and is also in close contact with the outer diameter side of the elastic cylinder, A retaining case is fitted onto the pressurized cylinder, forming a sealed pressurized liquid inflow space between it and the pressurized cylinder, and having a pressurized liquid inflow / outflow port that penetrates radially; A powder storage space axial pressing member pressurizes the powder storage space inward from both sides in the axial direction, In a powder pressure molding apparatus having a central angle of 180° in the rolled portion and pressure members that pressurize the elastic cylindrical body inward from both sides in the axial direction, The hardness of the elastic cylinder is higher than that of the pressurized elastic cylinder, The radius of the curved surface is equal to the thickness of the pressurized elastic cylinder. The above problem was solved by a powder pressure molding apparatus characterized in that the end face of the pressurized elastic cylinder and / or a part of the rolled portion are exposed in the pressurized liquid inflow space. [Effects of the Invention]

[0009] According to the present invention, the present invention comprises an elastic cylinder having a powder storage space on its inner diameter side, a pressurizing cylinder fitted to the elastic cylinder and having a through hole penetrating in the radial direction, and having curved surfaces with a central angle of 180° or more at both ends in the axial direction, a pressurizing elastic cylinder that is in close contact with the inner diameter side of the pressurizing cylinder and is provided so as to be bent at both ends so as to have a central angle of 180° or more to form bent portions, and is also in close contact with the outer diameter side of the elastic cylinder, a holding case fitted to the pressurizing cylinder and forming a sealed pressurized liquid inflow space between itself and the pressurizing cylinder, and having a pressurized liquid supply and discharge port penetrating in the radial direction, and a powder storage space axial pressurizing member that pressurizes the powder storage space inward from both sides in the axial direction. In a powder pressure molding apparatus equipped with a central angle of 180° for the rolled portion and pressurizing members that pressurize the elastic cylinder inward from both sides in the axial direction, the hardness of the elastic cylinder is higher than that of the pressurized elastic cylinder, the radius of the curved surface of the pressurized cylinder is equal to the thickness of the pressurized elastic cylinder, and the end face and / or part of the rolled portion of the pressurized elastic cylinder are exposed to the pressurized liquid inlet space. Therefore, when pressurized liquid is supplied from the pressurized liquid inlet / outlet port, the pressure from the pressurized liquid is transmitted to the pressurized elastic cylinder through the through hole and also to the end face and / or part of the rolled portion of the pressurized elastic cylinder exposed to the pressurized liquid inlet space, resulting in axial outward pressurization. Here, since the rolled portion of the pressurized elastic cylinder is pressed inward from both sides in the axial direction by the rolled portion pressurizing members, the axial pressurization of the pressurized elastic cylinder is canceled out, and radial inward pressurization is easily applied. As a result, powder can be pressurized well even with liquids at relatively low pressure, and the various components such as the pressurized elastic cylinder are less likely to be damaged even with liquids at relatively high pressure. Therefore, it is possible to provide a powder pressure molding apparatus that combines good pressurization performance and durability.

[0010] Furthermore, if the pressurized cylinder has a thickened section that occupies at least a portion of the pressurized liquid inflow space, the amount of pressurized liquid used during pressurization can be reduced.

[0011] Furthermore, if at least one of the axial pressure members in the powder storage space is configured to absorb the outward force in the axial direction when the inward pressure from both sides in the axial direction is released, it is possible to absorb the demolding expansion of the powder that occurs when the pressure on the powder is released, and the pressurized powder can be easily removed from the powder pressure molding apparatus. [Brief explanation of the drawing]

[0012] [Figure 1] A longitudinal cross-sectional view of a first embodiment of the powder pressure molding apparatus of the present invention. [Figure 2] Enlarged cross-sectional view of the main part shown in Figure 1. [Figure 3] A longitudinal cross-sectional view of a second embodiment of the powder pressure molding apparatus of the present invention. [Figure 4] An enlarged cross-sectional view of the main part of the third embodiment of the powder pressure molding apparatus of the present invention. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to Figures 1 to 4. However, the present invention is not limited to these embodiments.

[0014] As shown in Figure 1, the powder pressure molding apparatus 100 has a cylindrical holding case 10. The holding case 10 is provided with one or more pressurized liquid supply and discharge ports 12 that penetrate radially from the outer diameter side to the inner diameter side. The holding case 10 may be made of a high-strength material (for example, carbon steel). The pressurized liquid supplied and discharged from the pressurized liquid supply and discharge ports 12 may be oil, glycerin, boric acid solution, etc.

[0015] In the space on the inner diameter side of the holding case 10, a cylindrical pressurizing cylinder 52 is disposed. That is, the holding case 10 is externally fitted to the pressurizing cylinder 52. As shown in FIG. 2, the pressurizing 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 pressurizing cylinder 52. The pressurizing cylinder 52 is formed of a high-strength material (for example, carbon steel or the like).

[0016] On the inner diameter side of the pressurizing cylinder 52, a cylindrical pressurizing elastic cylinder 62 is disposed. The pressurizing elastic cylinder 62 is in close contact with the inner diameter side of the pressurizing cylinder 52 and is mounted on the pressurizing cylinder 52 so as to be wound at both ends 54 of the pressurizing cylinder 52 so that the central angle becomes 180° or more to form a wound portion 63. The thickness of the pressurizing elastic cylinder 62 is set to be equal to the radius of curvature of the curved surfaces at both axial ends of the pressurizing cylinder 52. The pressurizing 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 pressurizing elastic cylinder 62, a cylindrical elastic cylinder 64 is disposed (see FIG. 1). That is, the pressurizing cylinder 52 is externally fitted to the elastic cylinder 64. Further, the outer diameter side of the elastic cylinder 64 is defined such that the diameters of the elastic cylinder 64 and the pressurizing elastic cylinder 62 are in close contact with each other. 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 pressurizing elastic cylinder 62. Also, the thickness of the elastic cylinder 64 is preferably thicker than that of the pressurizing elastic cylinder 62.

[0018] The powder storage space 48 contains the powder 44 to be pressurized. 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. Lids 42 are respectively disposed on both sides in the axial direction of the pressurizing 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 lids 42.

[0019] The central angle of the winding portion 63 of the pressurized elastic cylinder 62 within a range of 180° and the elastic cylinder 64 are configured to contact the pair of annular pressurizing members 24, 34. Then, as will be described later, pressures from both sides in the axial direction 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 within a range of 180° and the elastic cylinder 64 are respectively pressurized from both sides in the axial direction 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 provided respectively 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, there are 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 sides in the axial direction of the pressurizing cylinder 52 toward the inside by the 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 also contacts the pressurizing member 24, the pressurizing member 24 is also pressed.

[0021] On the other hand, the axial pressure member 32 of the powder storage space 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 absorbing member 36 provided on the axial pressure member 32 of the powder storage space. Here, the pressure case 38, which engages with the axial pressure member 32 of the powder storage space, is screwed into the holding case 10, thereby pressing the lid portion 42 on the other side and the pressure member 34. The kinetic energy absorbing member 36 is a cylinder equipped with an elastic member such as a spring, and is configured to bias the axial pressure member 32 of the powder storage space in the opposite direction to the powder storage space 48. The pressure case 38 is also provided with a cylinder pressurized liquid inlet / outlet 35 for supplying and discharging pressurized liquid into and out of the sealed space between it and the axial pressure member 32 of the powder storage space. When pressurized liquid is supplied to the sealed space between it and the axial pressure member 32 of the powder storage space through the cylinder pressurized liquid inlet / outlet 35, the axial pressure member 32 of the powder storage space compresses the cylinder of the kinetic energy absorbing member 36 and moves in the direction of the powder storage space 48. In other words, when the inward pressure from both sides in the axial direction is released, the axial pressurizing member 32 of the powder storage space can absorb the outward force in the axial direction. The pressurized liquid supplied and discharged from the cylinder pressurized liquid inlet / outlet port 35 can be oil, glycerin, boric acid solution, etc.

[0022] When pressurized liquid is supplied to the pressurized liquid inlet space 14 through the pressurized liquid inlet / outlet port 12, as shown in Figure 2, the pressurized liquid passes through the through hole 56 and pressurizes the pressurized elastic cylinder 62, and also pressurizes the pressurized elastic cylinder 62 from its end face and / or a part of the curled portion 63. Meanwhile, the pressurized elastic cylinder 62 is subjected to inward pressure from both sides in the axial direction of the pressurized cylinder 52 by the pressurizing members 24 and 34. Here, the pressure from the pressurizing members 24 and 34 is transmitted to the curled portion 63 of the pressurized elastic cylinder 62, but the pressure from the pressurized liquid is also transmitted to the curled portion 63 from its end face and / or a part of the curled portion 63. Therefore, the pressure applied to the pressurized elastic cylinder 62 from the pressurized liquid is less likely to escape from the curled portion 63 and is more likely to be transmitted to the elastic cylinder 64. In other words, the pressure from the pressurized liquid is easily transmitted from the elastic cylinder 64 to the powder 44, resulting in a powder pressurizing apparatus 100 with good pressurizing performance.

[0023] Furthermore, the pressure from the pressurizing members 24 and 34 and the pressure from the pressurized liquid cancel each other out at both ends of the pressurized elastic cylinder 62, thus preventing deformation or damage to the pressurized elastic cylinder 62, which is directly subjected to pressure from the pressurized liquid. Therefore, the powder pressure molding apparatus 100 has high durability.

[0024] Here, the powder pressure molding apparatus 100 can also be configured to include a thickened portion 58 that occupies at least a part of the pressurized liquid inflow space 14, such as the pressurized cylinder 52. With this configuration, the amount of pressurized liquid used during pressurization can be reduced.

[0025] Furthermore, if at least one of the axial pressure members 22 and 32 of the powder storage space, such as the axial pressure member 32 of the powder storage space of the powder pressure molding apparatus 100, is configured to absorb the outward force in the axial direction when the inward pressure from both sides in the axial direction is released, it is possible to absorb the demolding expansion of the powder 44 that occurs when the pressure on the powder 44 is released, and the pressurized powder 44 can be easily removed from the powder pressure molding apparatus 100.

[0026] Figure 3 is a longitudinal cross-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 used for similar components and their descriptions are omitted. The differences will be described below.

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

[0028] Kinetic energy absorbing members 26a and 36a are provided between the axial pressing members 22a and 32a of the powder storage space and the powder storage space 48a, respectively. The kinetic energy absorbing members 26a and 36a are made of an elastic material such as rubber and are configured to absorb the outward force in the axial direction when the inward pressure from both sides in the axial direction of the pressing cylinder 52a is released. Therefore, this configuration can also absorb the demolding expansion of the powder that occurs when the pressure on the powder stored in the powder storage space 48a is released, and the pressed powder can be easily removed from the powder pressure molding apparatus 100a.

[0029] Figure 4 shows a rubber mold 70 that can be housed in the powder storage spaces 48, 48a. A pair of lids 42a are provided on both sides in the axial direction of the pressurized cylinder (not shown) of the rubber mold 70. The rubber mold 70 is composed of multiple rubber mold members 72a to 72f, and powder 44a is filled into the spherical space formed inside them. Therefore, a spherical molded product can be obtained using the rubber mold 70. In addition, molded products of various shapes can be obtained by changing the shape of the rubber mold.

[0030] As described above, the present invention provides a powder pressure molding apparatus that combines good pressurization performance and durability. [Explanation of Symbols]

[0031] 10 retaining cases 12 Pressurized liquid inlet / outlet 14 Pressurized liquid inflow space 22,32 Powder storage space axial pressurizing member 24,34 Pressurizing member 48 Powder storage space 52 Pressurized cylinder 54 End 56 Through hole 58 Thick part 62 Compressed Elastic Tube 63 Rolled-up section 64 Elastic Tube 100 Powder Compression Molding Apparatus

Claims

1. An elastic cylindrical body having a powder storage space on its inner diameter side, A pressurized cylinder is fitted onto the elastic cylinder, has a through hole that penetrates radially, and has curved surfaces with a central angle of 180° or more at both ends in the axial direction, A pressurized elastic cylinder is provided that is in close contact with the inner diameter side of the pressurized cylinder, and is bent at both ends so that the central angle is 180° or more to form a bent portion, and is also in close contact with the outer diameter side of the elastic cylinder, A retaining case is fitted onto the pressurized cylinder, forming a sealed pressurized liquid inflow space between it and the pressurized cylinder, and having a pressurized liquid inflow / outflow port that penetrates radially; A powder storage space axial pressing member pressurizes the powder storage space inward from both sides in the axial direction, In a powder pressure molding apparatus having a central angle of 180° in the rolled portion and pressure members that pressurize the elastic cylindrical body inward from both sides in the axial direction, The hardness of the elastic cylinder is higher than that of the pressurized elastic cylinder, The radius of the curved surface is equal to the thickness of the pressurized elastic cylinder. The end face of the pressurized elastic cylinder and / or a part of the rolled portion are exposed in the pressurized liquid inflow space, Powder pressure molding machine.

2. The powder pressure molding apparatus according to claim 1, wherein the pressure cylinder has a thickened portion that occupies at least a part of the pressurized liquid inflow space.

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

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