JPH11309755A - Injection molding container and injection mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a resin molded container, shaving-off work of a gate mark of which is unnecessary and injection filling pressure of which also can be reduced, by a method wherein the gate mark at molding is left in a recessed part, which is provided in some part of the curved surface shape of a bottom surface. SOLUTION: A blood-collecting container 1 has an external shape similar to that of a test tube, a long and narrow cylindrical main body part and a curved surface-shaped bottom part, which is a spherical surface and at the center of a recessed part 5 provided at the central part of which a gate mark 6 is left. In an injection mold, a projection 37 is provided at the central part of the spherical surface provide at some part of a molding surface. At the center of the projection 37, a gate 38 having a comparatively larger opening can be adopted, resulting in making the flow path resistance smaller and consequently the comparatively smaller injection filling pressure of an injection molder enough. Thus, since the gate mark 6 is hidden in the recessed part 5 and not exposed outside, no shaving-off of the gate mark 6 becomes unnecessary and a molding work can be executed with the molder having a low injection filling pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container such as a test tube or a blood collection container manufactured by injection molding having a curved bottom. The present invention also relates to an injection mold for manufacturing a container having a curved bottom surface such as a test tube or a blood collection container.

[0002]

2. Description of the Related Art Blood collection containers and test tubes have been made of glass in the past. However, in recent years, due to the development of new synthetic resin materials and advances in molding techniques, blood collection containers and the like made of synthetic resins are being used. The shape of a conventional blood collecting container made of synthetic resin is exactly the same as that of a conventional blood collecting container made of glass. That is, the blood collection container made of a synthetic resin of the related art has a cylindrical shape, and the bottom has a spherical shape.

[0003] In the prior art, an injection mold for injection-molding a blood collection container has a structure as shown in FIG. That is, the injection mold for molding the blood collection container is a well-known pin point gate type injection mold 100 as shown in FIG. 17, and has a fixed-side mounting plate 101 and a movable-side mounting plate 102 at both ends. A runner stripper plate 103, a fixed mold plate 105, a stripper plate 106, a movable mold plate 107, and a spacer plate 108 are provided between them. A sprue bush 110 is attached to the center of the fixed-side mounting plate 101, and a locate ring 112 is provided outside the sprue bush 110.
Is installed.

The fixed template 105 is a part for forming a blood collection container, and has a fixed template insert 122 mounted thereon.
The fixed-side template insert 122 is for molding the outer peripheral portion of the blood collection container, and has a hollow interior. In the prior art, in addition to the forming part forming the outer peripheral part of the blood collection container being provided on one fixed-side template insert 122, a gate part 127 is provided.
And the runner portion 128 are also formed.

The movable mold plate 107 has a movable insert (core).
123 are provided. The movable insert 123 is for molding the inner peripheral portion of the blood collection container. Movable side insert 123
Enters the above-mentioned fixed-side template insert 122 and forms a molding cavity 125 therebetween.

In the injection mold 100, a runner portion 130 is formed between the runner stripper plate 103 and the fixed mold plate 105, as in the known mold. A molding cavity 125 is in communication. A runner lock pin 132 is provided so as to pass through the fixed-side mounting plate 101 and the runner stripper plate 103, and the runner lock pin 132 is in contact with the branch portion of the runner section 130.

When a blood collection container is molded using the injection molding die 100 of the prior art, molten resin is injected from the sprue bush 110 and the runner 1
After 30, the molding cavity 125 is filled with a molten resin. Then, the resin is cooled and solidified, the injection mold 100 is opened, and the blood collection container as a molded product is released.

[0008]

The blood collection container of the prior art has the same shape as the conventional glass blood collection container as described above, but the blood collection container of this shape is molded by the above-described ordinary injection mold. Then, a problem peculiar to injection molding occurs. That is, in the conventional blood collecting container made of resin, since the bottom portion is spherical, the molding cavity is also spherical accordingly. As shown in FIGS. 17 and 18 (a), a gate is provided at a spherical portion for forming the bottom of the blood collection container.
The resin is filled into the molding cavity from the spherical part. Then, as shown in FIG. 18B, the injection mold 100 is divided and the blood collection container as a molded product is released.
When dividing 0, the gate trace 135 as shown in FIG.
Remains. Therefore, in the related art, after the molded product is released from the injection mold 100, an operation of scraping the gate mark 135 is required.

In addition, the prior art injection molding die 100
Are dissatisfied with the fact that the number of molded products is small for their size. That is, since the blood collection container has an elongated shape like a test tube, it is desirable that the molding cavity 125 be densely formed in the projection plane in order to effectively use the cross-sectional area of the injection mold 100. . However, due to the characteristics of the injection mold 100 of the pinpoint gate type, it is necessary to arrange the runner lock pin 132 at the branch portion of the runner portion 130. On the other hand, the injection mold 10 having a normal structure is used.
0, the fixed side mounting plate 101 and the runner stripper plate 1
Since the runner lock pin 132 is provided so as to penetrate through the hole 03, the runner lock pin 132 cannot be provided in front of the sprue bush 110. That is, since the blood collection container has an elongated shape, if only the arrangement of the molding cavities 125 is considered, a short center-to-center distance between the molding cavities 125 is sufficient, but the runner lock pin 132 may be provided in front of the sprue bush 110. Because of the restriction that the sprue bush 110 cannot be used, an unnecessary space is formed in a front part of the sprue bush 110. More specifically, since it is necessary to provide the runner lock pin 132 avoiding the sprue bush 110, the arrangement of the molding cavities 125 must be as shown in FIG. I can do it. For this reason, the conventional technique has a problem that the injection molding die is large for the number of moldings. In addition, an injection mold 100 for molding a blood collection container is also provided.
Then, by reducing the flow resistance of the molten resin during injection molding,
There is a demand to reduce the injection filling pressure.

The present invention pays attention to the above-mentioned problems of the prior art, invents a shape of a resin molding container which does not require the operation of scraping the gate mark 135, and develops an injection mold for molding this container. It is another object of the present invention to develop an injection mold capable of molding a larger number of pieces and reducing the injection filling pressure.

[0011]

According to the present invention, there is provided a container manufactured by injection molding having a curved bottom portion, wherein a concave portion is provided in a part of the curved bottom portion, An injection-molded container characterized in that the recess has a gate mark at the time of molding.

In the injection-molded container of the present invention, a concave portion is provided in a part of the curved surface at the bottom, and the concave portion has a gate mark at the time of molding. Therefore, the gate mark is hidden by the concave portion and is not exposed to the outside. Therefore, it is not necessary to scrape off gate traces after molding.

According to a second aspect of the present invention, which is a more specific version of the above-described invention, the injection-molded container has a cylindrical shape.

Further, the invention of the injection molding die is directed to an injection molding die for producing a container having a curved bottom portion, which has a molding cavity in which a main body portion and a curved surface portion serving as a bottom are partially curved. A projection is provided on a part of the curved surface, and a gate is formed at a tip of the projection.

The invention of the injection molding die of the present invention has a molding cavity in which a part for forming a main body part and a curved surface part serving as a bottom is a curved surface, and a projection is provided in a part of the curved surface part. I have. For this reason, the molding cavity is depressed by the projection, and a recess is formed in a part of the curved surface of the molded product. In the injection mold of the present invention, since the gate is formed at the tip of the projection, the gate mark remains in the concave portion of the molded product. Therefore, when the container is molded using the injection mold of the present invention, the gate mark does not protrude from the curved portion,
There is no need to cut gate traces in a later process. Further, in the injection molding die of the present invention, since the gate is provided at the tip of the projection, the liner can be easily separated, and the diameter of the gate can be made relatively large. Therefore, the flow path resistance during injection molding is small.

According to a fourth aspect of the present invention which is an improvement of the above-described invention, the molding cavity is constituted by an outer surface molding portion for molding the outer surface of the container, and an insert for molding the inner surface of the container. The injection molding die according to claim 3, wherein a corner including the curved surface portion is configured by mounting a member separate from other portions of the outer surface forming portion.

In the injection molding die of the present invention, the curved surface portion of the outer surface molding portion, which is relatively difficult to process, is made of a member separate from other portions. Therefore, in the injection mold of the present invention,
The curved surface portion can be processed independently, and the manufacture of the mold is easy.

According to a fifth aspect of the present invention, the container to be molded is cylindrical, and has a groove extending in the longitudinal direction on the inner surface of the open end of the container. An annular projection is provided in the vicinity of the groove and on the back side of the container, and the injection molding die has a projection that forms the groove,
The injection molding die according to claim 3, further comprising an annular groove that forms the annular protrusion, wherein a terminal of the protrusion that forms the groove has an arc shape spreading outward. It is.

The injection mold of the present invention is suitable for molding a blood collection container or a container having a similar structure. That is, after collecting blood, the blood collection container is plugged with rubber or the like to prevent blood from spilling. Therefore, in the blood collection container, an annular projection is provided on the inner surface of the opening portion so that the stopper does not come off. Similarly, make sure that the stopper does not rotate easily.
A groove extending in the axial direction is provided outside the annular projection. However, since the projections and the grooves are located close to each other, considerably precise processing is required when processing the injection mold.
On the other hand, the injection molding die of the present invention employs an arc shape that spreads outward at the end of the projection that forms the groove, so that the portion can be manufactured by milling.

According to a sixth aspect of the present invention, there is provided a sprue bush, a runner portion connecting the molding cavity and the sprue bush, and a runner lock pin in contact with the runner portion. The injection mold according to any one of claims 3 to 5, wherein the sprue bush is divided into two or more bush pieces, and a runner lock pin is mounted on at least one of the bush pieces. is there.

In the injection mold of the present invention, the sprue bush is divided into two or more bush pieces, and the bush pieces are provided with runner lock pins. Therefore, in the injection molding die of the present invention, the runner lock pin can be provided in front of the sprue bush, and the branch portion of the runner can be located at this position. Therefore, in the injection molding die of the present invention, a molding cavity for molding a container can be provided in front of the sprue bush. Therefore, in the injection mold of the present invention, the length of the runner portion can be reduced. Further, the molding cavities can be provided more densely.

The invention according to claim 7, which has the same configuration, operation and effect as the invention according to claim 6 described above,
In a molding cavity, a sprue bush, a runner part connecting the molding cavity and the sprue bush, and an injection mold having a runner lock pin in contact with the runner part, the sprue bush is divided into two or more bush pieces, An injection molding die, wherein a runner lock pin is mounted on at least one of the bush pieces.

[0023]

Embodiments of the present invention will be described below. FIG. 1 is an overall perspective view of a blood collection container according to an embodiment of the present invention, a partially sectional perspective view of an opening, and an enlarged perspective view of a bottom. FIG. 2 is a cross-sectional view of an injection mold for molding a blood collection container. FIG. 3 is an explanatory view showing the arrangement of the molding cavities of the injection mold of FIG. FIG. 4 is a front view and a sectional view of a sprue bush employed in the injection mold of FIG. FIG. 5 is an enlarged sectional view of a main part of the injection mold of FIG. FIG. 6 is a front view of the movable insert. FIG.
FIG. 3 is a cross-sectional view of the vicinity of a gate portion of the injection molding die of FIG. 2 and a cross-sectional view of the relevant portion when the injection molding die is separated. FIG. 8 is an enlarged cross-sectional view of the bottom of the blood collection container released from the injection mold shown in FIG. FIG. 9 is a cross-sectional view of the periphery of a gate portion of an injection mold according to another embodiment, and a cross-sectional view of the relevant portion when the injection mold is separated. FIG. 10 is an enlarged cross-sectional view of the bottom of the blood collection container released from the injection mold shown in FIG. FIG. 11 is a front cross-sectional view and a plan view of an opening of the blood collection container in FIG. 1. FIG. 12 is an explanatory view showing a manufacturing process of the movable-side insert for molding the portion shown in FIG. FIG. 13 is a front sectional view and a plan view of an opening of a blood collection container according to another embodiment. FIG. 14 is an explanatory diagram showing a manufacturing process of the movable insert for molding the portion shown in FIG. FIG. 15 is an explanatory diagram illustrating a divided form of the fixed-side template insert. FIG. 16 is an explanatory diagram illustrating a fixed-side mold plate insert of an injection mold according to another embodiment.

In FIG. 1, reference numeral 1 denotes a blood collection container according to an embodiment of the present invention. The blood collection container 1 of the present embodiment is made of polyethylene terephthalate resin, and has an outer shape similar to a test tube. That is, the main body portion 2 of the blood collection container 1 has an elongated cylindrical shape. The bottom 3 of the blood collection container 1 has a curved shape. The shape of the bottom 3 of the blood collection container 1 is more specifically a spherical surface. Here, a characteristic configuration of the blood collection container of the present embodiment is that a concave portion 5 is provided at the center of the bottom portion 3. A gate mark 6 is left at the center of the concave portion 5.

The inner surface of the opening of the blood collection container 1
As shown in FIGS. 11A and 11B and FIG. 11, four grooves 8 extending in the axial direction are provided at equal intervals. Further, an annular projection 10 is provided adjacent to the depth of the groove 8. In the blood collection container 1 of the present embodiment, the annular projections 10 are provided in two rows. FIGS. 1 (a) and 1 (b) show the terminal of the groove 8 provided on the inner surface of the opening, that is, the joint portion of the groove 8 with the projection 10.
An arc-shaped portion 12 extending outward as shown in FIG. 11 is provided.

Next, the injection mold 20 for manufacturing the blood collection container 1 will be described. The basic configuration of the injection mold 20 is the same as that of the conventional injection mold 100, and has a fixed-side mounting plate 21 and a movable-side mounting plate 22 at both ends, and a runner stripper plate 23 between them. A fixed mold plate 25, a stripper plate 26, a movable mold plate 27, and a spacer plate 28 are provided. And fixed side mounting plate 2
A sprue bush 30 is attached to the center of the unit 1, and a locate ring 32 is mounted outside the sprue bush 30.

The fixed-side template 25 is a part for forming a blood collection container, and has a fixed-side template insert 33 mounted thereon as in the prior art. The movable mold insert 27 is provided on the movable mold insert 27, and a molding cavity 56 is formed between the movable mold insert 50 and the fixed mold insert insert 33, as in the prior art.

In the injection mold 20 of this embodiment,
The first point to note is the structure of the sprue bush 30. As shown in FIG. 4, the sprue bush 30 used in the injection mold 20 of the present embodiment is divided into two bush pieces in the injection direction, and both are integrated with the locate ring 32 by screws 39. I have. That is, the sprue bush 30 employed in the present embodiment is divided into two members, a tip side bush piece 40 and a rear side bush piece 41. More specifically, the outer shape of the distal-side bush piece 40 has a shape in which the engaging portion 43 having a tapered distal end and the flange portion 45 are integrated.
A hole 42 into which the head of the liner lock pin 47 is inserted is provided in the flange portion 45 of the tip side bush piece 40. The inner surface shape of the distal-side bush piece 40 has a tapered portion 44 at which the distal end portion of the nozzle matches, and a through-hole portion 46 communicating with the hole of the nozzle. On the other hand, the rear-side bush piece 41 has an outer shape that is the flange portion 45 of the distal-side bush piece 40.
The inside has a shape that forms a tapered shape integral with the tip-side bush piece 40 described above.

In the present embodiment, the head of the runner lock pin 47 is mounted in the space surrounded by the hole 42 of the tip side bush piece 40 and the rear side bush piece 41 of the sprue bush 30, and the main body of the runner lock pin 47 is provided. The portion is exposed from the sprue bush 30. Therefore, in the present embodiment, the runner lock pin 47 is provided at a position closer to the center of the injection mold 20 as compared with the related art. The runner lock pin 47 provided on the sprue bush 30 is in contact with the branch portion of the runner section 60. Needless to say, a runner lock pin 49 is also provided at a portion penetrating the fixed-side mounting plate 21 and the runner stripper plate 23 as in the prior art, and the runner lock pin 49 is connected to the other branch of the runner portion 60 described above. Is in contact with the department.

In the injection molding die 20 of this embodiment, the runner lock pin 47 is provided on the sprue bush 30 itself, and the runner lock pin 47 can be located in front of the sprue bush 30. Thus, the molding cavities 56 can be arranged more densely. In addition, in the injection molding die 20 of the present embodiment, the molding cavity 56 can be provided at a position close to the sprue bush 30 and the length of the runner part 60 is shorter than that of the injection molding die of the related art. 60 has a small flow path resistance. Therefore, the injection filling pressure of the injection molding machine needs to be relatively small.

FIG. 3 is a layout view of the molding cavity 56 of the injection molding die 20 of the present embodiment, and shows the molding cavity 1 of the prior art injection molding die 100 shown in FIG.
It turns out that it is denser than the arrangement of 25.

The fixed-side mold plate 22 has 16 fixed-side mold plate inserts 33 (see FIG. 3). In the injection molding die 20 of the present embodiment, each fixed-side mold plate insert 33 is provided. 33 is further divided into two nesting pieces 35,36. That is, the structure of the fixed-side template insert 33 is as shown in FIG. The fixed side template insert 33 has a main body insert 35 and a gate insert 36. The former main body nesting piece 35 is for forming the outer periphery of the main body 2 of the blood collection container 1. Further, the latter gate portion insert piece 36 forms a central portion of the spherical surface of the bottom portion 3 and a part of the gate 38 and the liner portion. And body part nesting piece 3
The gate insert piece 36 is inserted into 5 to form an integral fixed-side mold insert 33. Injection mold 2 of the present embodiment
In the case of No. 0, only the periphery of the gate portion, which is difficult to process, can be processed alone, so that the manufacture of the mold itself is easy. Further, since the peripheral portion of the gate 38 wears more heavily than other portions, when the wear has progressed, it is also possible to replace and repair only the gate insert 36.

FIG. 15A schematically shows the size and positional relationship between the main body nesting piece 35 and the gate nesting piece 36 in the injection molding die 20 of this embodiment.
The ratio of the size of the two and the like are arbitrary. For example, as shown in FIG. 15B, the gate nesting piece 36 ′ may reach the part where the main body 2 of the blood collection container 1 is formed. According to the injection molding die 20 of the present embodiment, a parting line is generated at the bottom of the blood collection container 1, and FIG.
With such a configuration, a parting line is generated in the main body 2, but there is no functional disadvantage in any case. As a matter of course, as shown in FIG. 16, the fixed-side mold insert 33 'may be constituted physically by one member.

The gate insert piece 36 of the fixed mold insert 33
A projection 37 as shown in FIG. 7A is provided at the center of the spherical surface, which is a part of the molding surface constituted by. The shape of the protrusion 37 is substantially frustoconical. The projection 37
Protrudes into the molding cavity 56 and forms the recess 5 in the blood collection container 1 as a molded product. A gate 38 is opened at the center of the projection 37 of the gate insert 36. In the present embodiment, a straight shape is adopted as the shape of the gate 38. Alternatively, as shown in FIG.
It is also recommended to use a gate 38 ′ having a larger cross-sectional area toward the molding cavity 56. In addition, in the injection molding die 20 of the present embodiment, the gates 38 and 38 'having a relatively large opening as shown in FIG. 9 can be employed. Low resistance. Therefore, the injection filling pressure of the injection molding machine needs to be relatively small.

The movable mold plate 27 is provided with a movable insert 50 as in the prior art. The outer shape of the movable insert 50 is as shown in FIGS.
1 and a base 52 on the base side. Molding part 51
Enters the fixed-side template insert 33 and
Is a part where a molding cavity 56 is formed, and has a shaft-like shape, and has a spherical end portion. A projection 55 is provided at a portion near the base 52 of the molding portion 51, that is, at a portion where the opening of the blood collection container 1 is molded, as shown in FIGS. The projection 55 is for forming the groove 8 extending in the axial direction at the opening of the blood collection container 1 as a molded product. Further, the molded portion 51 is provided with an annular groove 53 adjacent to the projection 55. The groove 53 is provided for forming the annular protrusion 10 at the opening of the blood collection container 1. An arc-shaped portion 61 is provided at the joint of the projection 55 with the annular groove 53 as shown in FIG.

The manufacturing method of the annular groove 53 and the projection 55 is as follows.
As shown in FIG. That is, as shown in FIG. 12A, an annular groove 53 is provided by a turning tool 59, and a large diameter portion 57 is formed adjacent to the groove 53. Subsequently, as shown in FIG.
0 is cut in the axial direction to form the projection 55. Here, at the time of processing, the end mill 60 does not penetrate the portion 57 having a large diameter and performs processing while leaving the end. as a result,
At the junction of the projection 55 with the annular groove 53, an arc-shaped portion 61 spreading outward remains. When the lathe processing and the milling by the end mill are completed, the surface is polished and adjusted to a predetermined surface roughness.

The configuration in which the arc-shaped portion 61 is left at the joint portion of the projection 55 with the groove 53 like the injection molding die 20 of the present embodiment is such that the projection 55 can be formed by the end mill as described above. Recommended for FIG. 1 shows another example.
As shown in FIG. 4, it is possible to adopt a configuration in which the projection 55 'is formed without leaving the arc-shaped portion. However, the projection 55' is adjacent to the annular groove 53 and the gap between them is small. If the configuration does not leave an arc-shaped portion because it is small, machining by an end mill is difficult, and a machining method with low removal efficiency such as electric discharge machining must be resorted to.

When the blood collection container 1 is molded by using the injection molding die 20 of the present embodiment, molten resin is injected from the sprue bushing 30 as in the prior art, and is passed through the runner section 60 as shown in FIG. ) Is filled with a molten resin. Then, the resin is cooled and solidified, and an injection mold 2 is formed.
0 is opened to release the blood collection container 1 as a molded product. When opening the injection mold 20, first, the fixed side mold plate insert 33 is opened.
Between the movable side insert 50 of the movable side mold plate 25 and FIG.
They separate as shown in (b). At this time, the part of the gate is cut and the runner and the blood collection container 1 as a molded product are separated, but the protrusion 6 of the gate mark stops in the recess 5 of the blood collection container 1 and the recess 5
It is not exposed outside. Subsequently, the blood collection container 1 as a molded product is released from the movable insert 50 of the movable mold plate 27. The shape of the bottom of the blood collection container 1 immediately after the release is as shown in FIG. Are not exposed to the outside of the concave portion 5, and post-processing of the bottom is unnecessary.

In the injection mold 20 of this embodiment, the runner lock pin 47 is provided at a position close to the center of the sprue bush 30, the runner portion 60 is short, and the opening of the gate 38 is relatively large. Therefore, the flow resistance of the resin is small. Therefore, according to the present embodiment, a low injection filling pressure required for filling the resin is sufficient. Further, since the molding cavities 56 can be densely arranged, the projected area of the injection mold 20 is small, compact, and the total weight is small. Hereinafter, examples which demonstrate these effects will be described.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The layout shown in FIGS.
An injection mold of the present invention for molding one blood collection container at a time was manufactured. As a comparative example, a conventional injection molding die for molding 16 blood collection containers was manufactured according to the layout shown in FIGS. Comparing the two injection molds, the injection mold of the present invention had a projected area 40% smaller than that of the prior art. In addition, the total weight of the injection mold of the present invention was 40% lighter than that of the prior art. Furthermore, when the injection molding mold of the present invention and the injection molding mold of the prior art were used to actually perform the injection molding of the blood collection container, the injection filling pressure required by the injection molding mold of the present invention was 60% less than the injection filling pressure required by the state of the art injection molds was sufficient.

In the embodiment described above, the present invention has been described by taking as an example a blood collection container and an injection mold for molding the blood collection container. However, the present invention is not limited to a blood collection container.
The present invention is applicable to containers for other uses having a curved bottom, and injection molding dies for molding the containers. The configuration in which the sprue bush is divided into two and the runner lock pin is provided on the sprue bush can be widely applied to an injection molding die for molding a large number of small molded products.

[0042]

In the injection-molded container according to the first and second aspects, the gate mark is hidden by the concave portion and is not exposed to the outside. Therefore, it is not necessary to scrape off gate traces after molding. Therefore, the injection-molded container of the present invention does not require secondary processing after injection molding, and has the effect of being easy to manufacture.

Further, the injection mold according to claim 3 is
There is a molding cavity in which a part for forming the main body and a curved surface serving as a bottom has a curved surface, and a projection is provided in a part of the curved surface. Therefore, a concave portion is formed in a part of the curved surface portion in the molded product. In the injection mold of the present invention, since the gate is formed at the tip of the projection, the gate mark remains in the concave portion of the molded product. Therefore, when the container is molded using the injection mold of the present invention, the gate mark does not protrude from the curved surface portion, and there is no need to cut the back of the gate in a later step. Therefore, when the injection molding container is molded by the injection molding die of the present invention, the secondary processing after the injection molding becomes unnecessary, and there is an effect that the injection molding container can be easily manufactured. Further, in the injection molding die of the present invention, since the diameter of the gate can be made relatively large, the molding operation can be performed by a molding machine having a small flow path resistance during injection molding and a low injection filling pressure. Also, a small clamping force of the molding machine is sufficient.

In the injection molding die according to the fourth aspect,
Since the curved surface portion of the outer surface forming portion, which is relatively difficult to process, is made of a member separate from other portions, there is an effect that the injection mold is easily manufactured.

[0045] Similarly, the injection molding die according to the fifth aspect can perform detailed processing by milling, so that the working efficiency in the production of the die is good.

Furthermore, in the injection molding die according to the sixth and seventh aspects, since a molding cavity can be provided in front of the sprue bush, a large number of molded products can be molded at one time despite the small external shape. can do. Further, since the length of the runner portion can be shortened, the molding operation can be performed by a molding machine having a low flow path resistance during injection molding and a low injection filling pressure. Also, a small clamping force of the molding machine is sufficient.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a blood collection container according to an embodiment of the present invention, a partially sectional perspective view of an opening, and an enlarged perspective view of a bottom.

FIG. 2 is a sectional view of an injection mold for molding a blood collection container.

FIG. 3 is an explanatory view showing an arrangement of a molding cavity of the injection mold of FIG. 2;

FIG. 4 is a front view and a sectional view of a sprue bush employed in the injection mold of FIG. 2;

FIG. 5 is an enlarged sectional view of a main part of the injection mold of FIG. 2;

FIG. 6 is a front view of a movable side insert.

FIG. 7 is a cross-sectional view of the vicinity of a gate portion of the injection molding die of FIG. 2 and a cross-sectional view of the relevant portion when the injection molding die is separated.

FIG. 8 is an enlarged cross-sectional view of the bottom of the blood collection container released from the injection mold shown in FIG. 7;

FIG. 9 is a cross-sectional view of the periphery of a gate portion of an injection mold according to another embodiment, and a cross-sectional view of the relevant portion when the injection mold is separated.

10 is an enlarged sectional view of the bottom of the blood collection container released from the injection mold shown in FIG. 9;

11 is a front sectional view and a plan view of an opening of the blood collection container in FIG. 1;

FIG. 12 is an explanatory view showing a manufacturing process of a movable insert for molding the portion shown in FIG. 11;

FIG. 13 is a front sectional view and a plan view of an opening of a blood collection container according to another embodiment.

FIG. 14 is an explanatory view showing a manufacturing process of a movable insert for molding the portion shown in FIG. 13;

FIG. 15 is an explanatory diagram illustrating a divided form of the fixed-side template insert.

FIG. 16 is an explanatory view illustrating a fixed-side mold plate insert of an injection mold according to another embodiment.

FIG. 17 is a cross-sectional view of an injection mold for molding a blood collection container according to the related art.

18 is a cross-sectional view of the vicinity of a gate portion of the injection mold of FIG. 17 and a cross-sectional view of the relevant portion when the injection mold is separated.

FIG. 19 is an explanatory view showing an arrangement of a molding cavity of the injection mold of FIG. 17;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blood collection container 2 main body part 3 bottom part 5 concave part 6 gate mark 8 groove extending in axial direction 10 projection 27 movable mold plate 30 sprue bush 33 fixed mold plate insert 35 main unit insert piece 36, 36 'gate insert Piece 38, 38 ′ gate 40 tip-side bush piece 41 rear-side bush piece 43 engaging part 45 flange part 47 runner lock pin 50 movable side insert 51 forming part 53 annular groove 55 projection extending in the axial direction 56 molding cavity 60 runner Part 61 Arc-shaped part

Claims (7)

[Claims] 1. A container manufactured by injection molding having a curved bottom portion, wherein a concave portion is provided in a part of the curved surface portion of the bottom portion, and the concave portion has a gate mark at the time of molding. container. 2. The injection molded container according to claim 1, wherein the injection molded container has a cylindrical shape. 3. An injection molding die for producing a container having a curved bottom portion, the injection molding die having a main body portion and a partially curved molding cavity for molding a bottom curved surface portion. A projection is provided on the portion, and a gate is formed at the tip of the projection. 4. The molding cavity is constituted by an outer surface molding portion for molding the outer surface of the container, and a nest for molding the inner surface of the container, and one corner including the curved surface portion of the outer surface molding portion is formed at another portion of the outer surface molding portion. The injection molding die according to claim 3, wherein a member separate from the mold is mounted. 5. The container to be molded is cylindrical, has a groove extending in the longitudinal direction on the inner surface of the open end of the container, and has an annular shape near the groove of the container and on the back side of the container. A projection is provided, and the injection molding die has a projection that forms the groove,
The injection molding die according to claim 3, further comprising an annular groove that forms the annular protrusion, wherein a terminal of the protrusion that forms the groove has an arc shape spreading outward. . 6. A sprue bush, a runner portion connecting the molding cavity and the sprue bush, and a runner lock pin contacting the runner portion, wherein the sprue bush is divided into two or more bush pieces. The injection mold according to any one of claims 3 to 5, wherein a runner lock pin is mounted on at least one of the molds. 7. An injection molding die having a molding cavity, a sprue bush, a runner portion connecting the molding cavity and the sprue bush, and a runner lock pin in contact with the runner portion, wherein the sprue bush comprises two or more bushes. An injection mold, which is divided into pieces and at least one of the bush pieces is provided with a runner lock pin.