JP4586483B2 - Hollow member manufacturing apparatus and hollow member manufacturing method - Google Patents

Description

The present invention relates to a hollow member manufacturing apparatus and a hollow member manufacturing method.
Nozzles used in ink jet printers, dispensers, wire bonding, etc., orifices used in capillaries, pipes, etc. are axial members, and hollow spaces such as through holes are formed along the axial direction. A formed hollow member is used. The inner diameter of the hollow space in such a hollow member has been reduced as the performance of ink jet printers, valves, and the like is improved. At present, a hollow member having a hollow space with a diameter of 10 μm or less is required.
The present invention relates to a hollow member manufacturing apparatus and a hollow member manufacturing method having such a small-diameter hollow space.

In the production of a hollow member having a hollow space such as a small-diameter through hole, injection molding capable of forming a hollow space simultaneously with the molding of the hollow member is employed (for example, Patent Documents 1 to 6).
Injection molding is a technology that manufactures a member molded into the shape of a cavity by injecting and solidifying a flowable material into a cavity that is closed by a fixed mold and a movable mold. If a member is arranged, the member is formed into a cavity shape, and a hollow space is formed in the member at a location where the core pin is disposed in the cavity.

However, in the hollow member manufactured by the method as described above, the hollow space is formed in the same shape as the core pin, so the inner diameter of the hollow space is the same size as the core pin. For this reason, it is necessary to use a very thin core pin in order to reduce the inner diameter of the hollow space in the hollow member. However, at present, since only a core pin having a diameter of about 10 μm can be manufactured, a hollow member having an inner diameter of 10 μm or less cannot be manufactured. Even if a core pin having a diameter of 10 μm or less can be manufactured, the strength of such a core pin is very weak. Therefore, when a material is injected into the cavity, an uneven force is generated from the radial direction of the core pin in the circumferential direction. If added, the core pin may be damaged.
In addition, if a material such as ceramics mixed with a binder of an organic compound is used as a material, a hollow member having an inner diameter of about 8 μm is manufactured by sintering a member manufactured using a core pin having a diameter of 10 μm. However, even in this case, a hollow member having an inner diameter of 8 μm or less cannot be manufactured.

JP2003-181811 JP 2001-145912 A JP-A-11-090963 JP 08-099305 A JP 07-253521 A JP 05-329813 A

  In view of the above circumstances, an object of the present invention is to provide a hollow member manufacturing apparatus and a hollow member manufacturing method capable of manufacturing a hollow member having a hollow space whose inner diameter is smaller than the diameter of the core pin.

A hollow member manufacturing apparatus according to a first aspect of the present invention is formed between a fixed mold, a movable mold provided so as to be able to approach and separate from the fixed mold, and the movable mold being brought close to the fixed mold. An apparatus comprising a material supply unit for supplying a fluid material into a cavity, wherein the cavity has a central axis parallel to the moving direction of the movable mold , and the diameter is from the proximal end to the distal end. Pins formed so as to become narrower are disposed, the material supply unit is provided in the movable mold, and one end thereof serves as an input port for supplying the material into the cavity from the tip side of the pin. The material flow path is formed so that the central axis thereof is coaxial with the central axis of the pin.
According to a second aspect of the present invention, there is provided the hollow member manufacturing apparatus according to the first aspect, wherein the material supply unit heats the mixture of the thermoplastic binder and the powder mixed in the thermoplastic binder, and the heated material is used as the material. It is characterized by comprising a heating unit for supplying to the flow path.
The manufacturing method of the hollow member of the third invention includes a fixed mold and a movable mold provided so as to be able to approach and separate from the fixed mold, and in a state where the movable mold is brought close to the fixed mold, between them A method of manufacturing a hollow member by solidifying the fluid material using a device in which a cavity for containing the fluid material is formed, wherein the fluid member is fluidized in the movable mold. A material flow path for supplying a material having a property is provided, and a charging port for introducing a fluid material from the material flow channel into the cavity is formed on a surface of the movable mold forming the cavity. A pin having a central axis parallel to the moving direction of the movable mold is disposed in the cavity, and the movable mold is brought close to the fixed mold and has fluidity in the cavity. The From a state in which the volumes of material contained within the cavity prior to solidification, characterized in that for separating the movable die from the fixed die.
According to a fourth aspect of the present invention, there is provided the method for manufacturing a hollow member according to the third aspect, wherein the insertion port is disposed on an extension line in the axial direction of the pin.
A hollow member manufacturing apparatus according to a fifth aspect of the present invention is characterized in that, in the third aspect, the fluid material comprises a fluid binder and powder mixed with the binder.

According to the first invention, since the central axis of the material flow path is formed so as to be coaxial with the central axis of the pin arranged in the cavity, even if the material is supplied into the cavity from the input port, Only a rotationally symmetrical and uniform force is applied to the pin around the central axis of the hollow space. Therefore, when a material is supplied, no force is applied to the pin to bend the pin, so that it is possible to prevent the pin from being damaged or the position of the pin from being shifted when the material is supplied. . In addition, since the material in the material flow path and the material in the cavity are integrated via the inlet, if the movable mold is separated while the material in the cavity is not solidified, The material in the cavity can be pulled by the material, and the material accommodated in the cavity can be extended along the moving direction of the movable mold as the movable mold moves. Then, since the central axis of the pin arranged in the cavity is parallel to the moving direction of the movable mold, the material extends in a state where the space formed by the pin exists. Moreover, when the material is stretched, the length perpendicular to the moving direction of the movable mold, in other words, the length of the pin in the radial direction is shortened, and the stretched portion has a thin material and a narrow internal space. . Therefore, it is possible to form a hollow member having a space whose inner diameter is smaller than the diameter of the pin arranged in the cavity. And even when the material is stretched, the material and pins are only subjected to rotational symmetry and uniform force around the center axis of the hollow space, and no force that bends the material is applied at all, so when the material stretches, It is possible to prevent the hollow space from being crushed and the material extending portion from being bent.
According to the second invention, since the thermoplastic binder has fluidity by heating the material, the material can be smoothly supplied into the cavity. If the material is solidified, a member having a hollow space can be formed. Moreover, if the solidified member is heated, the binder is removed, the powder is sintered, and the hollow member shrinks, so that the inner diameter of the internal space of the hollow member can be further reduced, and the wall thickness of the hollow member is also reduced. can do.
According to the third invention, since the material in the material flow path and the material in the cavity are integrated via the inlet, if the movable mold is separated while the material in the cavity is not solidified, The material in the cavity can be pulled by the material in the material flow path, and the material accommodated in the cavity can be extended along the moving direction of the movable mold as the movable mold moves. Then, since the central axis of the pin arranged in the cavity is parallel to the moving direction of the movable mold, the material extends in a state where the space formed by the pin exists. Moreover, when the material is stretched, the length perpendicular to the moving direction of the movable mold, in other words, the length of the pin in the radial direction is shortened, and the stretched portion has a thin material and a narrow internal space. . Therefore, it is possible to form a hollow member having a space inside whose inside diameter is smaller than the diameter of the pin arranged in the cavity.
According to the fourth invention, when the material is stretched, only a rotationally symmetrical and uniform force is applied to the material and the pin around the central axis of the hollow space. That is, since no force that bends the material is applied at all, it is possible to prevent the hollow space from being crushed or the material extending portion from being bent when the material is stretched.
According to the fifth invention, if the solidified member is heated after the material is solidified, the binder is removed, the powder is sintered, and the hollow member contracts, so that the inner diameter of the internal space of the hollow member can be further reduced. And the thickness of the wall of a hollow member can also be made thin.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a schematic explanatory view of the hollow member manufacturing apparatus 1 of the present embodiment. In the same figure, the code | symbol B has shown the fixed frame in the manufacturing apparatus 1 of the hollow member of this embodiment, and the code | symbol MF is arrange | positioned above the fixed frame B and can move to an up-down direction, in other words, the fixed frame B The moving frame provided so that it can approach and separate is shown.

As shown in FIG. 3, a fixed mold 2 is attached to the upper surface of the fixed frame B. The fixed mold 2 is formed with a substantially cylindrical space 2h (hereinafter simply referred to as a space 2h) that is recessed downward from the upper surface 2A. The space 2h of the fixed mold 2 is formed such that its central axis CA is parallel to the moving direction of the moving frame MF, and a pin 4 is disposed inside the space 2h. The pin 4 is formed so that the diameter thereof becomes narrower from the lower end toward the upper end, and the center axis thereof is arranged so as to be coaxial with the center axis CA of the space 2h. It extends to a throttle portion 3b of a through hole 3h described later.
The cross-sectional shape of the space 2h and the pin 4 in the direction orthogonal to the axial direction is not limited to a circle, and may be a quadrangle, a triangle, or the like as long as the shape is rotationally symmetric around the central axis.

On the other hand, as shown in FIG. 3, the movable mold 3 is attached to the lower surface of the moving frame MF. The movable mold 3 is formed with a through hole 3h penetrating in the vertical direction. The upper end portion of the through hole 3h is connected to a heating portion (not shown) for heating and fluidizing a thermoplastic material such as plastic through the nozzle 6. The through hole 3h is formed so that its central axis is coaxial with the central axis CA of the space 2h in the fixed mold 2, and its inner diameter increases toward the lower surface 3A along the moving direction of the movable mold 3. Is formed such that a portion (throttle portion 3b) having the smallest inner diameter is positioned slightly above the lower surface 3A.
The cross-sectional shape in the direction perpendicular to the axial direction of the through-hole 3h is not limited to a circle, and may be a quadrangle, a triangle, or the like as long as it is a rotationally symmetric shape around the central axis.

  Since the configuration is as described above, the lower surface 3A of the movable mold 3 can be brought into contact with the upper surface 2A of the fixed mold 2 by moving the movable frame MF so that the movable mold 3 approaches the fixed mold 2. Then, the through hole 3h of the movable mold 3 and the space 2h in the fixed mold 2 are communicated, and a space that is blocked from the outside by the through hole 3h and the space 2h is formed between them. If the material fluidized in the heating section is supplied to this space through the nozzle 6, the material fills the through hole 3 h of the movable mold 3 and the space 2 h of the fixed mold 2.

At this time, since the central axis of the through hole 3h and the pin 4 of the movable mold 3 is coaxial with the central axis CA of the space 2h of the fixed mold 2, the through hole 3h and the pin 4 of the movable mold 3 are coaxial. In addition, the center of the throttle 3b is also located on the axial extension of the pin 4. Therefore, the material supplied from the nozzle 6 flows into the space 2h of the fixed mold 2 from the through hole 3h of the movable mold 3 through the throttle portion 3b. At this time, the material is the center of the space 2h of the fixed mold 2 It flows only in the direction of the axis CA, and almost no flow occurs in the direction intersecting the central axis CA. For this reason, when the material flows into the space 2h from the through hole 3h of the movable mold 3, only a rotationally symmetrical and uniform force is applied to the pin 4 around the central axis of the space 2h, and the force that bends the pin 4 is Since it hardly occurs, it is possible to prevent the pin 4 from being damaged when the material is supplied or the position of the pin 4 from being shifted from the center of the space 2h.
Therefore, if the material is solidified in a state where the material is filled in the through-hole 3h of the movable mold 3 and the space 2h of the fixed mold 2, the material is removed from the through-hole 3h of the movable mold 3 and the space 2h of the fixed mold 2. The hollow member can be formed into a shape and has a hollow space on the position of the pin 4 in the space 2h, that is, on the central axis.
As described above, it is desirable that the central axis of the nozzle 6 is also coaxial with the central axis CA of the space 2 h of the fixed mold 2 in order not to generate a bending force with respect to the pin 4. That is, it is desirable that the central axes of the space from the space 2h to the nozzle 6 of the fixed mold 2 are all coaxial.

  In the through hole 3h of the movable mold 3 and the substantially cylindrical space 2h of the fixed mold 2, the portion where the pin 4 is present, that is, the space below the throttle portion 3b of the through hole 3h is the cavity C in the claims. The space above it is the material flow path 5 referred to in the claims, and the narrowed portion 3b is the inlet referred to in the claims. Hereinafter, the space below the throttle portion 3b in the through hole 3h and the space 2h of the fixed mold 2 are defined as the cavity C, and the space above the throttle portion 3b in the through hole 3h is defined as the material flow path 5.

As shown in FIG. 1, in the hollow member manufacturing apparatus 1, the movable die 3 is moved closer to the fixed die 2 and the fluid C is accommodated in the cavity C, and then accommodated in the cavity C. Before the material M is solidified, when the viscosity becomes strong, the movable mold 3 is separated from the fixed mold 2 (FIG. 1B). Since the material M in the material flow path 5 and the material M in the cavity C are integrated via the throttle 3b, the material M in the cavity C can be pulled by the material M in the material flow path 5. Then, the material M accommodated in the cavity C can be extended along the moving direction (vertical direction in FIG. 1) of the movable mold 3 with the movement of the movable mold 3. At this time, since the central axis of the pin 4 arranged in the cavity C is parallel to the moving direction of the movable mold 3, the extending portion of the material M, in other words, the movable mold 3 and the fixed mold 2. The portion located between the two extends in a state where the space formed by the pins 4 exists.
In addition, since the material M accommodated in the cavity C extends in the vertical direction, only the length of the material M remains constant, so that the direction is perpendicular to the moving direction of the movable mold 3, in other words, For example, the length of the pin 4 in the radial direction is shortened. Then, in the material M accommodated in the cavity C, the length of the pin 4 in the radial direction is reduced in the portion located in the space 2 h of the fixed mold 2, and between the movable mold 3 and the fixed mold 2. The located part also has a narrow internal space. That is, since the extending part of the material M has both an outer diameter and an inner diameter that are smaller than when the portion is located between the positions in the space 2 h of the fixed mold 2, the movable mold 3 is fixed to the fixed mold 2. As compared with the case where the material having fluidity is solidified in the cavity C while being close to the hollow member, a hollow member having a small inner diameter of the hollow portion can be formed. In other words, a hollow member having an inner diameter smaller than that of the pin 4 can be formed.

The central axis of the through hole 3h of the movable mold 3, the central axis of the pin 4, and the central axis CA of the space 2h of the fixed mold 2 are all located on the same axis, and the central axis of the space 2h of the fixed mold 2 Since CA is parallel to the moving direction of the movable mold 3, when the material M extends, the material M contracts uniformly along the radial direction of the pin 4. For this reason, since the force which bends the material M does not generate | occur | produce at all when the material M expands, it can prevent that a hollow space is crushed or the part where the material M is extended is bent.
The pin 4 may have the same diameter from the lower end to the upper end. However, when the hollow member is formed by the above method, the upper end, that is, the end on the movable mold 3 side is sharp. What is present is preferred. In this case, since the frictional resistance generated between the pin 4 and the material M can be reduced when the material M stretches, damage to the material M can be prevented, and the inner surface of the hollow member after molding The accuracy can be increased.

  As shown in FIG. 2, the hollow member 10 manufactured by the above-described method has an end portion (base end) located on the movable die 3 side from a portion (base end) located on the bottom of the fixed die 2 ( The diameter is reduced toward the tip, and the hollow space inside is also formed so that the inner diameter is reduced from the base end toward the tip.

  Here, in the case where the hollow member is manufactured with the movable die 3 being brought close to the fixed die 2 in the hollow member manufacturing apparatus 1 of the present embodiment, in the case of this hollow member, the shape of the pin 4 is the same. A hollow space is formed, and the material M located in the cavity C below the contact surface between the upper surface 2A of the fixed mold 2 and the lower surface 3A of the movable mold 3, that is, the tip of the pin 4 is arranged. Only the part except the part which can be made can be made into a product. This is because the tip of the pin 4 is hemispherical due to the influence of processing heat when the pin 4 is processed, and the inner surface of the hollow space (hereinafter simply referred to as the tip space) formed by the tip of the pin 4 is Since it becomes a spherical surface, the angle formed by the inner surface of the tip space with respect to the central axis of the pin 4 is different from the angle formed by the inner surface of other portions in the hollow space with respect to the central axis of the pin 4. Because it ends up. Therefore, in the hollow member manufactured with the movable mold 3 being close to the fixed mold 2, the minimum diameter of the hollow space is a pin at the position of the contact surface between the upper surface 2A of the fixed mold 2 and the lower surface 3A of the movable mold 3 It can only be the same length as the diameter D1 (see FIG. 3), and the pin diameter D1 is limited to 10 μm at most.

However, if the hollow member 10 is manufactured by the above-described method, a portion below the position of the lower surface 3A of the movable mold 3 (CL line in FIG. 1) is removed even if the portion where the tip of the pin 4 is disposed. It can be a product. Then, the minimum diameter of the hollow space of the hollow member 10 as a product is D2 (FIG. 2A), which can be made smaller than the pin diameter D1 in the conventional case. That is, the hollow member 10 having an inner diameter smaller than the diameter of the pin 4 arranged in the cavity C can be formed. Even if the diameter of the pin 4 is 10 μm, the hollow member 10 having an inner diameter of 1 μm or less. However, it can be manufactured.
And since the hollow member 10 is shape | molded so that the internal diameter of a hollow space may become small toward a front-end | tip from a base end, if the hollow member 10 used as a product is cut | disconnected in the position where the axial direction differs, it will differ. It can be set as the hollow member 10 which has an internal diameter.
Note that the angle formed by the inner surface of the hollow space with respect to the central axis of the pin 4 is the central axis of the pin 4 even in the portion above the position of the lower surface 3A of the movable mold 3 (line CL in FIG. 1). On the other hand, it is needless to say that the part having the same angle as the angle formed by the inner surface 10h in the part below the position of the lower surface 3A of the movable mold 3 can be a product.

  In addition, the material M has fluidity, for example, a binder such as vinyl acetate or an acrylic resin, a thermoplastic binder such as a plasticizer such as dibutyl phthalate, and the binder, for example, a metal It is also possible to use materials made of powder such as ceramics. In the case of a material consisting only of powder, the fluidity is poor and it is difficult to fill the material into the cavity C. However, if mixed with the binder as described above, the fluidity of the material is improved by heating the material. , Can be smoothly supplied into the cavity C. Moreover, after the material is cooled and solidified, the thermoplastic binder can be removed from the solidified material by heating the solidified material at a temperature higher than the evaporation temperature of the binder. Moreover, if the heating temperature is set to be equal to or higher than the sintering temperature of the powder, a hollow member in which the powder is sintered can be manufactured. Then, the hollow member in which the powder is sintered is reduced in volume by the volume of the removed binder as compared with the case where the material is cooled and solidified, and the volume is reduced by sintering the powder. Therefore, the volume of the hollow member after sintering can be reduced by about 20% or more. Then, since the wall thickness of the hollow member is reduced and the inner diameter of the internal space is also reduced, the hollow member 10 having an inner diameter of 1 μm or less can be more easily manufactured.

  The method for producing a hollow member of the present invention is suitable for producing a hollow member having a small inner diameter, which is used in an ink jet printer, a dispenser and the like.

It is explanatory drawing of the manufacture operation | work of the hollow member 10 by the manufacturing apparatus 1 of the hollow member of this embodiment, Comprising: (A) is the figure which showed the state which inject | poured the material M, (B) spaces apart the movable mold | type 3 It is the figure which showed the state made to do. It is explanatory drawing of the hollow member 10 manufactured with the manufacturing apparatus 1 of the hollow member of this embodiment, Comprising: (A) is a longitudinal cross-sectional view, (B) is a B arrow view of (A), ( (C) is a CC line arrow view of (A), (D) is a DD line arrow view of (A). It is a schematic explanatory drawing of the manufacturing apparatus 1 of the hollow member of this embodiment.

1 Hollow member manufacturing equipment 1
2 Fixed type 3 Movable type 4 Pin 5 Material flow path 10 Hollow member C Cavity

Claims (5)

A fixed mold, a movable mold provided so as to be able to approach and separate from the fixed mold, and a material having fluidity are supplied into a cavity formed between the movable mold and the fixed mold when the movable mold is brought close to the fixed mold. An apparatus including a material supply unit,
In the cavity, a pin having a central axis parallel to the moving direction of the movable mold and having a diameter narrowed from the proximal end toward the distal end is disposed,
The material supply unit is
Provided in the movable mold, one end of which is provided with a material flow path serving as an input port for supplying the material into the cavity from the tip side of the pin ,
The material flow path is formed so that the central axis thereof is coaxial with the central axis of the pin. The material supply unit
The heating part which heats the mixture of the thermoplastic binder and the powder mixed with this thermoplastic binder, and supplies this heated material to the said material flow path is provided. Hollow member manufacturing equipment. A cavity for containing a stationary mold and a movable mold provided so as to be able to approach and separate from the stationary mold, and for accommodating a fluid material between the movable mold and the stationary mold when the movable mold is brought close to the stationary mold A method for producing a hollow member by solidifying the fluid material using an apparatus in which is formed,
The movable mold is provided with a material flow path for supplying a fluid material into the cavity, and flows from the material flow path into the cavity on the surface of the movable mold forming the cavity. There is a slot for feeding materials with properties,
A pin having a central axis parallel to the moving direction of the movable mold is arranged in the cavity,
The movable mold is separated from the fixed mold from the state in which the movable mold is brought close to the fixed mold and the fluid material is accommodated in the cavity before the material accommodated in the cavity is solidified. A method for producing a hollow member characterized by the above. The method for manufacturing a hollow member according to claim 3, wherein the insertion port is disposed on an extension line in the axial direction of the pin. The method for producing a hollow member according to claim 3, wherein the material having fluidity comprises a binder having fluidity and powder mixed with the binder.

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