JP5106792B2 - Method and apparatus for forming cylindrical container - Google Patents

Description

  The present invention relates to a cylindrical container molding method and a molding apparatus for molding a bottomed tube made of a thermoplastic material such as glass by heating and softening into a cylindrical container.

  In order to analyze and measure the components and properties of various samples such as blood and reagents, for example, these various samples and reagents are placed in a glass cell (test tube) having a rectangular cross section and irradiated with light. Analyzing and measuring the state of the sample and the like based on the rate.

  Conventionally, when molding such a glass cell, a prismatic mold is inserted into a glass tube having a circular cross-section at the bottom, and the glass tube is heated and softened under vacuum to be molded into the outer shape of the mold. A method is known (see, for example, Patent Document 1).

In this case, the material of the mold is a material having a larger linear expansion coefficient than that of glass, the mold is released by using the difference in the linear expansion coefficient by cooling after molding, and the mold is extracted from the mold.
Japanese Examined Patent Publication No. 3-69852 (page 2-3, FIG. 3)

  However, in the technique described in Patent Document 1, when pulling out the glass cell as a molded product from the cored bar, there is only an insufficient gap, such as a small gap between the cored bar and the glass cell, If the glass cell is pulled out more than necessary, there is a risk that the optical surface that transmits light may be damaged, or the surface of the mold may be damaged in the glass cell.

  As described above, if the optical surface of the glass cell is scratched, when the optical surface is irradiated with light, the light is irregularly refracted and the analysis and measurement of the sample and the like cannot be performed correctly. In addition, if the surface of the mold is damaged, the mold cannot be used as a molding mold thereafter, resulting in an economical loss.

  The present invention has been made to solve such a problem, and the object of the present invention is to prevent excessive pulling force when the molded product is pulled out from the core metal, so that the molded product and the core metal are not damaged. It is an object of the present invention to provide a method for forming a cylindrical container and an apparatus for forming the same that can prevent the occurrence of the above.

In order to achieve the object, the invention according to claim 1
In a cylindrical container molding apparatus that covers a bottomed tube made of a thermoplastic material on a columnar cored bar standing on a base, heat-softens it, and molds it into a cylindrical container.
Supporting means is provided for supporting the cored bar in a swingable manner with the attachment base end side as the center.

The invention according to claim 2 is the cylindrical container forming apparatus according to claim 1,
The support means is characterized in that the metal core is supported so as to be slidable in the axial direction and rotatable about the axis.

The invention according to claim 3 is the cylindrical container forming apparatus according to claim 1 or 2,
The support means includes a spherical portion fixed to one of the base and the core metal,
It has the base and the support part formed in the other of the said metal core in order to support this spherical part, It is characterized by the above-mentioned.

The invention according to claim 4 is the cylindrical container forming apparatus according to any one of claims 1 to 3,
An elevating device that holds the bottom of the bottomed tube through the support means so as to be movable up and down;
Detecting means for detecting movement along the axial direction of the cored bar with respect to the base;
The detection means comprises control means for decelerating or stopping the drive of the lifting device by detecting a predetermined amount of movement of the cored bar.

The invention according to claim 5
In the method of forming a cylindrical container in which a bottomed tube made of a thermoplastic material is covered with a columnar core bar standing on a base, heated and softened, and molded into a cylindrical container,
The core bar is supported so as to be swingable around its attachment base end side,
When the bottomed tube is pulled out from the cored bar, the shaft of the cored bar is swung in a direction substantially coinciding with the pulling direction.

The invention according to claim 6 is the method for forming a cylindrical container according to claim 5,
The core metal is supported so as to be slidable in the axial direction and rotatable about the axis.

The invention according to claim 7 is the method for forming a cylindrical container according to claim 5 or 6,
When pulling out the bottomed tube, when the cored bar is in close contact with the bottomed tube and moves in the pulling direction together with the bottomed tube, the amount of movement is detected, and the bottomed tube is detected at a predetermined movement position. The drawing speed is reduced or stopped, and only the mandrel is lowered by its own weight.

  According to the present invention, when the molded product is pulled out from the core metal, the molded product is prevented from being damaged, and a high-performance molded product can be obtained. In addition, the core metal is prevented from being damaged, and the durability of the core metal can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Overall configuration of molding equipment)
1A and 1B are cross-sectional front views of a cylindrical container forming apparatus according to the present embodiment. In FIG. 1A, this forming apparatus 10 includes a prismatic cored bar 14 erected on a base 13 in the vertical direction, and glass as a thermoplastic bottomed tube that covers the cored bar 14 from the outer peripheral side. It has a tube 12, a vacuum pump 18 as a decompression means for decompressing the inside of the glass tube 12, and a heating furnace 16 as a heating means for heating and softening the glass tube 12.

A loading / unloading outlet 15 is opened at the bottom of the heating furnace 16, and the glass tube 12 and the cored bar 14 are collectively loaded from the loading / unloading outlet 15 to heat them.
In the present embodiment, a commercially available glass tube 12 is used and has a cylindrical inner diameter slightly thicker than the core metal 14. The glass tube 12 is formed in a bottomed cylindrical shape with a bottom portion 12a having a substantially hemispherical shape.

  Moreover, the material of the glass tube 12 is borosilicate glass having good light transmittance. However, the material of the glass tube 12 is not limited to glass, and for example, synthetic resin, quartz, or other members rich in light transmittance may be used.

  The metal core 14 has a prismatic shape with a substantially rectangular cross section, and is made of a material having a linear expansion coefficient larger than that of the glass tube 12 (for example, borosilicate glass). This is because when the glass tube 12 is molded and cooled, the cored bar 14 is greatly shrunk to form a gap with the inner wall of the glass tube 12 and can be easily pulled out from the cored bar 14 to prevent scratches. Because.

  In the present embodiment, a hard metal such as carbon tool steel (SK steel) or tungsten carbide (WC) is used as the core metal 14. In the present embodiment, for convenience of explanation, the glass tube 12 before and after molding will be described with the same reference numerals.

  Further, a housing 24 is provided integrally with the base 13 so as to cover the periphery of the base end side of the cored bar 14 standing on the base 13. An opening 26 is formed on the center side of the housing 24. At the time of molding, the glass tube 12 is inserted into the cored bar 14 through the opening 26. An O-ring 28 as a seal member is attached to the opening 26.

  Further, a mounting hole 31 is formed in the housing 24 toward the side, and a pipe 30 is inserted through the mounting hole 31. A vacuum pump 18 is connected to the other end side of the pipe 30.

  By sucking the air in the glass tube 12 in the direction of the arrow by the vacuum pump 18, the inside of the glass tube 12 can be decompressed to a substantially vacuum. That is, the above-described O-ring 28 serves to hold the opening 26 (atmospheric pressure) and the adjustment chamber 27 inside thereof in an airtight state with the glass tube 12 inserted into the opening 26.

  Further, as shown in FIG. 1B, the molding apparatus 10 includes an elevating apparatus 36 that grips the glass tube 12 supported so as to be swingable and slidable in the axial direction via a cored bar 14 after molding. It has. The lifting device 36 is provided with a chuck 34 as a holding means for holding the bottom 12a of the glass tube 12 on the tip side.

  In the present embodiment, an air cylinder is used as the lifting device 36. And the chuck | zipper 34 is moved to the arrow upward direction (vertical direction) of FIG.1 (b), and the glass tube 12 is pulled out from the metal core 14. FIG. The chuck 34 is made of, for example, a synthetic resin so as not to damage the glass tube 12.

  Further, the molding apparatus 10 includes a sensor 38 as a detecting means for detecting the movement amount (lifting amount) of the core bar 14 along the axial direction with respect to the base 13, and the sensor 38 lifts the core bar 14 by a predetermined amount. By detecting this, a control device 40 is provided as control means for decelerating or stopping the drive of the lifting device 36.

Further, the sensor 38 is fixed to the base 13 side and is not moved by the vertical movement of the chuck 34.
As will be described in detail later, when the glass tube 12 is pulled out, the lifting of the cored bar 14 is stopped halfway because the cored bar 14 is lowered by its own weight and the glass tube 12 is pulled out with a small force. Because.

FIGS. 2A and 2B are views showing a state when the cored bar 14 is attached to the base 13.
In the figure, a support member 21 having a spherical portion 20 formed at the tip is erected on the base 13. The metal core 14 is supported by the spherical portion 20 so as to be swingable (arrow A direction) and slidable in the axial direction (vertical direction, arrow B direction) about the mounting base end side (spherical portion 20 side). Has been.

  That is, a bottomed hole 22 as a support portion that slidably supports the spherical portion 20 is formed on one end side (lower end side) of the cored bar 14. The bottom of the bottomed hole 22 is formed into a substantially spherical surface. The spherical portion 20 and the bottomed hole 22 constitute a support means 19.

  The support means 19 supports the core metal 14 so as to be swingable around the spherical portion 20, and is slidable in the axial direction of the core metal 14, and further around the axis of the core metal 14 (arrow C). Direction).

  In the present embodiment, the case where the spherical portion 20 is formed on the base 13 side and the bottomed hole 22 is formed on the core metal 14 side as the support means 19 has been described. The bottomed hole 22 may be formed on the 13th side, and the spherical portion 20 may be formed on the cored bar 14 side.

Moreover, although this embodiment demonstrated the case where the spherical part 20 and the bottomed hole 22 were used as the support means 19, it is not restricted to this, For example, it is good also as a structure shown to Fig.3 (a) (b).
3A and 3B, a columnar support member 121 is erected on the base 13, and a bottomed hole 122 is formed on the cored bar 114 side. A predetermined clearance 123 is provided between the support member 121 and the bottomed hole 122. With this configuration, the cored bar 114 is supported so as to be swingable with respect to the support member 121 (in the direction of arrow A), slidable in the axial direction, and further rotatable about the support member 121.

Therefore, even when this configuration is adopted, the same function as the support means 19 described above is exhibited. Next, a specific forming process will be described.
(Set process before molding)
FIG. 4 shows a setting process in which the bottomed tube 12 before molding is placed on the cored bar 14. That is, the glass tube 12 is inserted so that the opening end faces downward so as to cover the cored bar 14 erected on the base 13 from the outer peripheral side. At this time, when the glass tube 12 is inserted into the opening 26 by the O-ring 28, the opening 26 and the inner adjustment chamber 27 are kept airtight.

  When the vacuum pump 18 is driven in this state, the air in the adjustment chamber 27 and the glass tube 12 is sucked and the pressure is reduced to a substantially vacuum state. When the pressure is reduced to a predetermined vacuum pressure, the driving of the vacuum pump 18 is stopped.

Next, the glass tube 12 (and the cored bar 14) is carried into the heating furnace 16 from the carry-in / out port 15 in a state where the inside of the glass tube 12 is decompressed to a substantially vacuum state (see FIG. 5).
(Process during molding)
FIG. 5 is a cross-sectional front view when the glass tube 12 is formed in the heating furnace 16.

  At this time, the glass tube 12 is carried in from the loading / unloading port 15 of the heating furnace 16 to a length of about half of the length, and is heated to a predetermined temperature together with the cored bar 14. As the heating temperature at this time, for example, a temperature equal to or higher than the glass transition point is employed. By this heating, the softened glass tube 12 is brought into close contact with the outer peripheral surface (transfer surface) of the cored bar 14. By doing in this way, the inner surface of the heat-softened glass tube 12 can be closely attached to the outer periphery of the core metal 14 without a gap.

  The reason why the glass tube 12 is heated to about half the length is that if it is heated to all lengths, it becomes difficult to pull it out from the cored bar 14, and such a length is not necessary. . Therefore, as will be described later, after the glass tube 12 is pulled out, it is cut in the middle in the longitudinal direction.

Further, in the present embodiment, the inside of the glass tube 12 is described as being in a substantially vacuum state before heating. However, the present invention is not limited to this. In this way, the glass tube 12 is heated and softened, and its inner surface is brought into close contact with the core metal 14 without a gap, and the transfer surface of the core metal 14 is accurately transferred to the glass tube 12. Further, the bottom of the glass tube 12 having a substantially hemispherical shape before being softened is in close contact with the end face (upper end face) on the front end side of the cored bar 14 to be formed into a flat bottom 12a.
(Drawing process after cooling)
FIG. 6 is a diagram showing a process when the glass tube 12 is cooled and pulled out after molding.

  As described above, since the metal core 14 is made of a material having a linear expansion coefficient larger than that of the glass tube 12, a gap is generated between the metal core 14 and the glass tube 12 during cooling. The cored bar 14 is pulled out through the gap.

  Therefore, as shown in FIG. 6, there is no problem if the glass tube 12 can be easily pulled out from the cored bar 14 with a small force by grasping the bottom portion 12 a of the glass tube 12 by an elevator device (not shown). However, in this case, since the glass is hard, when the core bar 14 is pulled out, the core bar 14 and the glass tube 12 are slidably contacted and easily damaged.

Therefore, in the present embodiment, the inner surface of the glass tube 12 and the surface of the cored bar 14 are prevented from being scratched after the molding and when being pulled out after cooling.
That is, in the present embodiment, the glass core 14 is supported at the time of drawing by supporting the core 14 so as to be swingable about its attachment base end and slidable in the axial direction (and further rotatable about the shaft). No excessive stress was generated on the core 12 and the cored bar 14.

FIG. 7 is a view showing a drawing process of the glass tube 12 according to the present embodiment.
As shown in FIGS. 1A and 1B, in order to pull out the molded glass tube 12 from the cored bar 14, the elevating device 36 is driven and the bottom portion 12 a of the glass tube 12 is held by the chuck 34. Next, the chuck 34 is pulled upward. At this time, as shown in FIG. 7, the glass tube 12 is not always pulled out in a state in which it coincides with the axial direction. This is because the center of the chuck 34 and the center of the glass tube 12 may deviate due to attachment error or backlash.

  In the present embodiment, as shown in FIG. 7, even if it is pulled out with an inclination in the direction of the arrow D with respect to the axis, the tip of the core metal 14 ( The upper end) also swings in the pulling direction so that no stress is applied to the glass tube 12 or the like.

  Further, when the glass tube 12 is pulled out, if the glass tube 12 is in close contact with the cored bar 14, the cored bar 14 is also lifted integrally with the glass tube 12 due to the adhesive force. In this case, the sensor 38 detects the amount of lifting of the cored bar 14. Then, when the core bar 14 is lifted by a predetermined amount, the pulling speed of the elevating device 36 is decelerated or stopped by a command from the control unit 40.

  Then, the metal core 14 descends by its own weight at the stop position or the deceleration position, and the glass tube 12 moves relative to the metal core 14 and is pulled out. At this time, only the own weight of the cored bar 14 acts on the glass tube 12. For this reason, an unnecessary force is not applied to the glass tube 12 and the cored bar 14, and the glass tube 12 and the cored bar 14 are prevented from being scratched.

In addition, as shown in FIG. 6, when the glass tube 12 does not adhere to the core metal 14 and the core metal 14 does not float up, the elevating device 36 moves and is pulled out without stopping.
Further, as shown in FIG. 7, in the glass tube 12, only the heated and softened part is in close contact with the cored bar 14, and the part not heated and softened (the non-molded part L ′) is in the state of the material in the cored bar 14. It is in a state of covering the surroundings. And the shape | molded glass tube 12 is cut | disconnected in the position of predetermined length part (L) from the bottom part, and non-molding part L 'is discarded.

  According to the present embodiment, when the glass tube 12 (molded product) after molding is pulled out from the cored bar 14, a force larger than the weight of the cored bar 14 as a pulling force is not applied to the molded product. Scratches can be prevented and a high-performance molded product can be obtained.

(A) and (b) are the cross-sectional front views of the shaping | molding apparatus of embodiment of this invention. (A) is the cross-sectional front view of the attachment state of a metal core, (b) is the top view. (A) is the cross-sectional front view of the attachment state of a metal core, (b) is the top view. It is a figure which shows the setting process before shaping | molding. It is a figure which shows the process in shaping | molding. It is a figure which shows the extraction process after cooling. It is a figure which shows a drawing-out process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molding apparatus 12 Glass tube 12a Bottom part 13 Base 14 Core metal 15 Carry-in / out port 16 Heating furnace 18 Vacuum pump 19 Support means 20 Spherical part 21 Support member 22 Bottomed hole 24 Housing 26 Opening part 27 Adjustment chamber 28 O-ring 30 Piping 31 Mounting hole 34 Chuck 36 Lifting device 38 Sensor 40 Control device 114 Metal core 121 Support member 122 Bottomed hole 123 Clearance

Claims (7)

A cylindrical container forming apparatus that covers a bottomed tube made of a thermoplastic material on a columnar cored bar standing on a base, heat-softens and forms into a cylindrical container ,
The cored bar supports the cored bar so as to be swingable with respect to the base about the mounting base end side of the cored bar, and is slidable with respect to the base in the axial direction of the cored bar. and support means for supporting,
A lifting device that lifts and lowers the bottomed tube while holding the bottom of the bottomed tube;
With
In the case where the support means operates to pull out the bottomed tube from the cored bar in a direction inclined with respect to the axial direction of the cored bar with the lifting device holding the bottom of the bottomed tube, The shaft is configured to swing the core bar in a direction substantially coinciding with the pulling direction.
The support means is configured to lower the cored bar by its own weight when the cored bar moves in the pulling direction together with the bottomed pipe while the cored bar is in close contact with the bottomed pipe. A cylindrical container molding device. The cylindrical container forming apparatus according to claim 1, wherein the support means is further configured to support the core metal so as to be rotatable about an axis of the core metal . The support means includes a spherical portion fixed to one of the base and the core metal,
And the base in order to support the spherical portion and the other to form a bearing of the core metal
The cylindrical container forming apparatus according to claim 1 , comprising: Detecting means for detecting a moving amount of the metal core in the axial direction Tsu along the metal core with respect to the base,
If the movement amount of the metal core has reached a predetermined amount, the lifting device further comprises a control means for controlling the lifting device so as to decelerate or stop the driving of claims 1 to 3 The forming apparatus of the cylindrical container in any one. A method for forming a cylindrical container in which a bottomed tube made of a thermoplastic material is covered with a columnar cored bar standing on a base, heated and softened to form a cylindrical container ,
The cored bar supports the cored bar so as to be swingable with respect to the base about the mounting base end side of the cored bar, and is slidable with respect to the base in the axial direction of the cored bar. Supporting
When the bottomed tube is pulled out from the cored bar in a direction inclined with respect to the axial direction of the cored bar, the axis of the cored bar is swung in a direction substantially coinciding with the drawing direction ;
Lowering the core metal by its own weight when the core metal moves together with the bottomed tube in the pulling direction with the core metal in close contact with the bottomed tube;
A method for forming a cylindrical container. The method for forming a cylindrical container according to claim 5, further comprising supporting the core metal so as to be rotatable around an axis of the core metal . When the core metal moves in the drawing direction together with the bottomed tube in a state where the core metal is in close contact with the bottomed tube, the core metal is lowered by its own weight, the shaft of the core metal with respect to the base Detecting the amount of movement of the mandrel along the direction, and when the amount of movement of the mandrel reaches a predetermined amount, reduce or stop the pulling speed of the bottomed tube , and a Rukoto is lowered by its own weight, method of molding a tubular container according to claim 5 or 6.