JP5954553B2 - Method for manufacturing storage frame - Google Patents

Description

The present invention relates to the production how the container frame, in particular, relates to the production how to manufacture a container frame of a synthetic resin.

Currently, storage bodies for storing various articles such as bags are used. The background art of the present invention will be described with respect to a suitcase as an example.
Generally, there are a soft case type and a hard case type as a suitcase. The soft case type is configured such that the case shell is formed of fabric, leather material, etc., and is opened and closed by a fastener. On the other hand, the hard case type has a pair of box-shaped synthetic resin case shells pivotally attached to each other and a pair of frame members respectively fixed to both case shells.

  Conventionally, such a frame material is made of aluminum, and since it is difficult to integrally mold the entire aluminum frame material, the frame material is formed by combining a plurality of constituent members. That is, a frame constituent member is formed by linear extrusion molding, and a frame material is manufactured through a hole punching process, a bending process, and a joining process.

In a suitcase with such an aluminum frame material,
Since the frame material is made of aluminum, the overall weight increases, and there is a problem that a burden is imposed on the user during handling. In addition, when the suitcase collides with various objects during transportation and a strong impact is applied to the frame portion, there is a situation where the impacted portion is recessed.

  As a result of the impact, the frame material is deformed, and the entire frame is distorted by such deformation, and as a result, it becomes difficult to mesh the pair of frame materials to which both case shells are fixed, and it can be used as a suitcase Sometimes it was difficult. Therefore, it has been conventionally required to solve such problems.

  For example, in Patent Document 1, in the technique of integrally molding a case shell and a frame with a synthetic resin, a gas is injected into a molten resin to form a hollow portion, without using a metal part, A suitcase with increased rigidity and reduced weight is described. However, the technique described in Patent Document 1 has increased rigidity in comparison with a conventional synthetic resin suitcase, and does not have rigidity comparable to an aluminum suitcase.

Further, in Patent Documents 2 and 3, in injection molding using a synthetic resin, a depression called a sink due to shrinkage of the resin accompanying cooling is caused by injecting a pressurized gas into the molten resin and pressing it against the surface of the mold. A technique for preventing such a situation has been disclosed.
However, the techniques described in Patent Documents 2 and 3 are techniques that press the molten resin against the surface of the mold with gas, and are not techniques that increase the rigidity.

The present patent applicant has also extracted other patent documents from such a viewpoint, but none of the techniques described in any of the publications has solved the problem.
Utility Model Registration No. 2558005 JP-A-10-291230 JP-A-9-29774 Utility Model Registration No. 3187221 Utility Model Registration No. 3183373 JP-A-9-308515

  The present invention is for solving such a conventional problem, and the problem is that the container has rigidity comparable to that of an aluminum frame, is lightweight, easy to use, and rich in durability. To provide a frame.

In order to achieve the above object, in the first aspect of the present invention, the main body side frame is provided with a pair of box-shaped main body side shell and lid side shell, and is fixed to the opening edges of the main body side shell and the lid side shell. And a container frame manufacturing method for injection-molding a container frame having a lid-side frame, the step of injecting a raw material made of molten polycarbonate containing carbon fibers cut into a predetermined dimension into the mold, Injecting gas into the mold filled with raw material at a pressure of 3 MPa to form a cavity inside the molten raw material, and holding the pressure at 3 MPa for 25 seconds after injecting the gas, a step starts to solidify by cooling the raw surface of the cavity, the gas after the raw surface of said cavity starts to solidify and injected pressurized to a pressure of 10 MPa, solid The step of increasing the steps of pressurizing toward the raw surface of the cavity started to inside the raw material, the composition density of the raw material by applying holding pressure of 15 seconds the 10MPa after injection by boosting the gas And pressurizing and injecting the gas to a pressure of 15 MPa , further pressurizing the raw material surface of the cavity toward the inside of the raw material, and pressurizing and injecting the gas to the 15 MPa for 20 seconds increasing the composition density of the raw material by holding pressure to the pressure, and having a step of have stiffness comparable to aluminum frames.

Therefore, in the first aspect of the present invention, a cavity is formed inside the molten raw material by injecting gas, and then the raw material surface of the cavity is cooled by the gas. By raising the pressure of the gas after the raw material surface of the cavity starts to cool and solidify, the raw material surface of the cavity that has started to solidify is pressurized toward the inside of the raw material. At this time, the cooling of the raw material proceeds at the same time, thereby increasing the composition density of the raw material.
Further, since the raw material is made of molten polycarbonate containing carbon fibers cut to a predetermined size, the carbon fibers are uniformly mixed with the polycarbonate and injection molded.

  The invention according to claim 2 is characterized in that the gas is nitrogen gas. Accordingly, the invention according to claim 2 functions to cool the high temperature raw material in which nitrogen gas is melted in the mold and to increase the composition density of the raw material.

The invention according to claim 3 is characterized in that the mold is provided with gas injection holes at predetermined intervals. Therefore, in the invention described in claim 3 , gas is uniformly injected into the mold.

The invention according to claim 4 is characterized in that the storage body is a suitcase.

In the first and second aspects of the present invention, the raw material surface of the hollow portion that has started to solidify is directed toward the inside of the raw material by pressurizing the gas after the raw material surface of the hollow portion has been cooled and solidified. It is configured to be pressurized.
In conventional injection molding, when a high pressure is applied to the molten raw material by gas, the contact surface with the gas is cooled rapidly, so warpage due to shrinkage or uneven cooling of the raw material surface. There was a problem that would occur. Moreover, even if a high pressure is applied, there is a problem that the molten raw material flows and is difficult to solidify.
On the other hand, in the first and second aspects of the invention, first, a gas is injected to form a cavity, and the raw material surface of the cavity is cooled. And warping can be prevented.
Subsequently, after the surface of the raw material of the cavity is cooled and solidified, the pressure of the gas is increased, whereby the surface of the raw material of the cavity that has started to solidify is pressed toward the inside of the raw material without flowing, and at the same time, the raw material As the cooling of the material proceeds, the composition density of the raw material increases.
As a result, the molded frame material has rigidity comparable to that of aluminum frame material in terms of toughness and elasticity.

Therefore, when it is applied to a bag or the like that is composed of a main body portion and a lid portion and the frame material is fixed to the opening portions of the main body portion and the lid portion and can be opened and closed, for example, transport Even when a frame is hit against an object and a strong impact is applied to the frame, the generated stress can be absorbed as appropriate, so there is no dent, and even when repeated impacts are applied, the frame is damaged. As a result, it is possible to avoid a situation in which the frames cannot be joined together and cannot be used as a bag.
As a result, according to the first and second aspects of the present invention, there is provided a storage frame that has a predetermined toughness and elasticity and is excellent in durability compared with a conventional case made of aluminum by using a synthetic resin. Can do.

In addition to the effects of the first and second aspects of the present invention, since the hollow portion is provided, even when an impact is applied when it hits an object at the time of transportation, the hollow portion is present, so that the frame material is provided. It is possible to provide a storage body frame in which the main body has high bending strength and easily absorbs stress due to impact.

In addition, in the case of a conventional aluminum frame, since various colors were applied to the frame raw material manufactured by mold forming in the painting process, the frame part was hit against an object during transportation. The paint may peel off, and the frame part may gradually peel off due to secular change, and the base as an aluminum material may be exposed, resulting in a defect that the appearance quality of the product as a whole is lacking. .
However, in the housing frame manufacturing method and the housing frame according to the present invention, a desired color frame can be manufactured by kneading various colors of paint into the mold raw material during molding. Therefore, in the present invention, there is no situation where the paint is peeled off at the time of use because it is not a color that is formed by coating the finished frame raw material to form a coating film. Even at the time of collision with other objects and over time, it is possible to maintain the same color as at the time of sale, and to maintain good appearance quality as a product.

In the invention described in claim 1 , since the raw material is made of molten polycarbonate containing carbon fibers cut to a predetermined size, the carbon fibers are uniformly mixed with the polycarbonate and injection molded. .
Polycarbonate is a thermoplastic and exhibits high physical properties in terms of transparency, impact resistance, heat resistance, and flame retardancy, and is also excellent in terms of mechanical strength. Carbon fiber is a fiber made by carbonizing acrylic fiber or pitch, which is a by-product such as petroleum, coal, coal tar, etc., at a high temperature, and its specific gravity is 1/4 when compared with iron. However, the strength is 10 times and the elastic modulus is 7 times, which is excellent in heat resistance, wear resistance, thermal stretchability and the like.
Therefore, in the invention described in claim 1 , since the composition density of the polycarbonate is increased and the carbon fibers are solidified in an evenly mixed state, the overall rigidity can be further increased.

In the invention according to claim 3 , since the gas is uniformly injected into the mold, it becomes possible to uniformly form the hollow portion inside the frame material, and to increase the composition density of the raw materials equally. it can. As a result, the rigidity as a whole can be ensured uniformly.

In the invention according to claim 4, it is possible to provide a suitcase which is elastic and has a durability that is resistant to deformation when subjected to an impact from the outside, has high durability, and is easy to handle.

It is a perspective view showing one embodiment of a suitcase in which a storage frame according to the present invention is used. FIG. 2 is a cross-sectional view corresponding to the line II-II in FIG. It is a flowchart which shows one Embodiment of the process of the manufacturing method of the storage body frame which concerns on this invention.

Hereinafter, based on the embodiment shown in the accompanying drawings, a case where the storage body frame according to the present invention is applied to a suitcase will be described in detail as an example.
FIG. 1 shows a suitcase 50 in which a container frame 40 manufactured by the method for manufacturing a container frame according to the present embodiment is used.

The suitcase 50 according to the present embodiment is a suitcase to which a so-called hard case type caster 53 is fixed, and a pair of box-shaped main bodies that are joined to each other via a hinge portion (not shown). A shell 51, a lid-side shell 52, and a storage body frame 40 are provided.
The housing frame 40 is fixed to the opening peripheral portion of the main body side shell 51 and the lid side frame 42 fixed to the opening peripheral portion of the cover side shell 52 and abuts in the width direction of the main body side frame 41. It consists of.
As shown in FIG. 2, in the storage body frame 40 according to the present embodiment, cavities 43, 44, and 49 are formed in both the main body side frame 41 and the lid side frame 42.

  That is, the main body side frame 41 is formed into a main frame portion 41a having a substantially square cross section and a horizontally long cross section, and is continuously joined from the width direction end portion to the thickness direction lower end portion of the main frame portion 41a. It has a sub-frame portion 41b and a narrow plate-like flange portion 41c extending outward from the upper end of the main frame portion 41a in the thickness direction of the non-sub-frame portion 41b.

A groove-shaped opening 41d formed by the locking protrusions 46 and 47 is formed in the entire lengthwise direction at the end in the width direction of the sub-frame portion 41b on the side opposite to the flange portion 41c. It is formed over.
A cavity 43 having a substantially semicircular cross section is formed continuously over the entire length direction in the main frame 41a, and a cavity 49 having a substantially rectangular cross section is formed in the sub-frame 41b. Has been.

  Further, on the outer side surface portion of the main frame portion 41a, a ridge portion 57 that protrudes outward from the lower end portion of the main frame portion 41a is formed. A groove portion 41e that opens outward is formed over the entire length direction below the flange portion 41c, and a peripheral edge portion 51a of the main body side shell 51 is fixed to the groove portion 41e by a tucker needle.

The lid side frame 42 is disposed to face the main body side frame 41 in the horizontal direction, and extends outward from the main frame portion 42a having a substantially rectangular cross section and the upper end in the thickness direction of the main frame portion 42a. It consists of a narrow plate-like flange portion 42b.
A groove-like opening 42c formed by a locking projection 45 provided outward is formed along the length direction at the lower side of the main frame 42a on the main body side frame 41 side. Yes.

Further, a groove portion 42d that opens outward is formed below the flange portion 42b of the frame portion main body 42a, and the peripheral edge portion 52a of the lid-side shell 52 is fixed by a tacker needle. A hollow portion 44 having a substantially trapezoidal cross section is formed in the main frame portion 42a.
As shown in FIG. 1, a key lock portion 55 and a handle fixing portion 56 are attached to the upper surface portion 54 of the sub-frame portion 41b of the main body side frame 41.

  Therefore, as shown in FIG. 2, in the present embodiment, when the main body side shell 51 and the lid side shell 52 are closed, the locking ridges 45 of the main frame portion 42a of the lid side frame 42 are While entering the groove-like opening 41d of the side frame 41, the locking projection 47 of the main body side frame 41 is disposed on the lower surface of the locking projection 45 of the lid side frame 42, and the locking projection 46 is By disposing in the groove opening 42c, the main body side frame 41 and the lid side frame 42 are joined in the width direction, and the main body side shell 51 and the lid side shell 52 are closed.

  The storage body frame 40 according to the present embodiment is manufactured by injection molding a raw material mixed with polycarbonate and carbon fiber with a mold under pressure with nitrogen gas.

  As shown in FIG. 3, in the present embodiment, step S10 for producing a raw material by mixing granular polycarbonate and carbon fiber cut to a predetermined size, and a step for injecting the molten raw material into a mold Nitrogen gas supply which is S12 which is an injection process which is S12, and which inject | pours gas into the said mold filled with the said raw material by predetermined pressure, and forms the cavity parts 43, 44, and 49 inside the said molten raw material A first pressure holding step that is a step S14 in which the pressure is maintained for a predetermined time after the gas is injected and the raw material surfaces of the cavities 43, 44, 49 are cooled and solidified, and the cavities 43, 44, 49 After the raw material surface starts to solidify, the gas is pressurized to a predetermined pressure and injected, and the raw material surfaces of the cavities 43, 44, 49 that have started to solidify are pressed toward the inside of the raw material. A primary nitrogen gas pressure-increasing step which is 5; a secondary pressure-holding step which is step S16 in which the composition density of the raw material is increased by pressure-injecting and injecting the gas for a predetermined time; And then pressurizing the surface of the raw material of the cavities 43, 44, 49 further toward the inside of the raw material, and a secondary nitrogen gas pressurization step, which is step S17, and pressurizing and injecting the gas and holding the pressure for a predetermined time. And a third pressure holding step which is step S18 for further increasing the composition density of the raw materials.

Hereinafter, the manufacturing method of the storage body frame 40 according to the present embodiment will be described.
As shown in FIG. 3, in the “mold raw material creation step” S10, 20 parts by weight of short cut carbon fibers are prepared and mixed with granular polycarbonate to exceed the melting temperature of polycarbonate of 250 ° C. A mold raw material is prepared by heating to 310 ° C. to melt the polycarbonate. Since polycarbonate is a thermoplastic resin, it reaches a melting state when it reaches a melting temperature.

Although not shown, an injection mold is used as the manufacturing mold used in the present embodiment. The injection mold is a hermetically sealed mold, and the main body side frame 41 and the lid side frame 42 are configured so as to be integrally formed by a single mold using separate injection molds. Similarly, although not shown in the drawing, this injection mold has eight resin injection holes at equal intervals along the length direction. The resin injection hole portion according to the present embodiment is configured to be used also as the gas injection hole portion.
Therefore, when injection molding is performed, as shown in FIG. 3, in the “mold clamping step” S11, the injection mold is clamped so that raw materials can be injected into the mold.

  Next, in the “injection step” S12, the mold raw material in a molten state is pressed into the injection mold that has been clamped from 8 resin injection holes in a uniform state by applying an injection pressure of 3 MPa, and the entire mold is pressed. To fill. In this case, since the temperature of the mold is lower than that of the injected resin, the polycarbonate, which is a thermoplastic resin containing carbon fibers, starts to solidify from the outer side of the molded product that is in contact with the inner surface of the mold.

  Next, in the “nitrogen gas supply step” S13, 3 seconds after the filling of the mold raw material is completed, a predetermined amount of nitrogen gas is injected into the injection mold from eight gas injection holes at a pressure of 3 MPa. Inject each in a uniform state. In this case, since nitrogen gas is injected into the mold with a pressure of 3 MPa, it gathers in the inward portion that is not solidified in the raw materials filled in the mold, and the hollow portion 43 made of nitrogen gas in the inner portion, 44, 49 begin to form.

Next, in the “first pressure holding step” S14, the pressure is held for 25 seconds while the pressure of the nitrogen gas is kept at 3 MPa. At this time, the nitrogen gas accumulated in the cavities 43, 44, 49 cools the mold raw material surfaces of the cavities 43, 44, 49 that are in a molten state at a high temperature, and the mold raw materials of the cavities 43, 44, 49 are The surface begins to solidify.
In particular, in the “mold raw material creation step” S10 according to the present embodiment, the mold raw material is heated and injected at 310 ° C., so that the “primary pressure holding step” S14 according to the present embodiment is suitable. Thus, by setting the holding time to 25 seconds, the surface of the mold raw material starts to solidify, but the inside of the mold raw material is maintained in a molten state.

  Next, in the “primary nitrogen gas pressurizing step” S15, the pressure of the nitrogen gas is increased to 10 MPa, and a predetermined amount is injected into the injection mold from the eight gas injection holes in a uniform state. . Thereby, the mold raw material surfaces of the cavities 43, 44, and 49 where the nitrogen gas has started to solidify are pressurized at a pressure of 10 MPa toward the inside of the molten raw material.

  Next, in the “second pressure holding step” S16, the pressure is maintained for 15 seconds while the pressure of the nitrogen gas is maintained at 10 MPa. At this time, the nitrogen gas accumulated in the cavities 43, 44, and 49 simultaneously cools the mold raw material while pressing the mold raw material surface that has started to solidify toward the inside of the molten mold raw material with a pressure of 10 MPa. In order to promote, the composition density of the mold raw material increases.

  Next, in the “secondary nitrogen gas pressurizing step” S17, the pressure of the nitrogen gas is increased to 15 MPa, and a predetermined amount is injected into each of the injection molds from the eight gas injection holes in a uniform state. . Thereby, the mold raw material surfaces of the cavities 43, 44, and 49 are further pressurized at a pressure of 15 MPa toward the inside of the molten raw material.

Next, in the “third pressure holding step” S18, the pressure is held for 20 seconds while maintaining the pressure of the nitrogen gas at 15 MPa. At this time, the nitrogen gas accumulated in the cavities 43, 44, and 49 further promotes cooling of the mold raw material while simultaneously pressing the mold raw material surface toward the inside of the molten mold raw material with a pressure of 15 MPa. The composition density of the mold raw material is further increased.
In the “third pressure holding step” S18 according to the present embodiment, by keeping the pressure holding time at 20 seconds, the mold raw material is brought to the inside in a state where the pressure of the nitrogen gas is kept at 15 MPa. Solidify completely.
Thereafter, in the “mold opening step” S19, the injection mold is opened, and the molded product is taken out from the inside, whereby the housing frame 40 according to the present embodiment is created.

In the conventional storage frame by injection molding, in the “nitrogen gas supply step” S13, 3 seconds after the filling of the mold raw material is completed, nitrogen gas is injected at a pressure of 3 MPa, and then the pressure of the nitrogen gas is increased to 3 MPa. By maintaining the pressure for 40 seconds to 50 seconds in the maintained state, the injection mold is opened after cooling to the inside of the mold raw material, and the molded product is taken out and created.
At this time, if nitrogen gas is injected at a high pressure such as 10 MPa, a high pressure is applied to the molten raw material, and the contact surface with the gas is rapidly cooled. There was a problem that warpage due to uneven cooling occurred. Further, even when high pressure is applied, the melted raw material flows and flows out of the mold, so that it is difficult to solidify.

In contrast, in the housing frame according to the present embodiment, nitrogen gas is first injected at a low pressure of 3 MPa to form the cavities 43, 44, and 49 and the cavities 43, 44, and 49. By cooling the surface of the raw material, sinking or warping of the surface of the raw material due to application of high pressure can be prevented.
Subsequently, after the raw material surfaces of the cavities 43, 44, 49 are cooled and solidified, the pressure of the nitrogen gas is increased, so that the raw material surfaces of the cavities 43, 44, 49 that have started to solidify do not flow. The composition density of the raw material is increased by being pressed toward the inside and simultaneously cooling the raw material.
As a result, the toughness and elasticity of the molded frame material are improved as compared with the conventional synthetic resin frame material.

Moreover, in the storage body frame 40 according to the present embodiment, since the carbon fiber is contained in the polycarbonate resin, the strength is further improved as compared with the conventional synthetic resin frame material, and aluminum. Rigidity comparable to the frame material made.
Therefore, when using a suitcase, when it hits another object, it has high impact resistance even when an impact is applied. Lower than in the case of a suitcase.

Here, (a) a housing frame 40 according to the present embodiment, (b) a housing frame created by the same method as the present embodiment using only polycarbonate as a raw material, and (c) conventional injection molding (D) The result of having done the test regarding bending strength in the storage body frame produced by (d) and the conventional aluminum frame is shown.
The storage frame by conventional injection molding of (c) is the “nitrogen gas supply step” S13, 3 seconds after the filling of the mold raw material is completed, after nitrogen gas is injected at a pressure of 3 MPa, By maintaining the pressure at 3 MPa for 40 seconds to 50 seconds, the injection mold is opened after cooling to the inside of the mold raw material, and the molded product is taken out.
The test regarding bending strength was performed by applying a load to the intermediate point of a test piece having a length dimension of 500 mm, a cross-sectional width dimension of 75 mm, and a cross-section height dimension of 19 mm with a distance between the fulcrums of 480 mm.
As a result, (a) was not deformed even at a load of 3400N, (b) was deformed at 3000N, (c) was whitened and deformed at 1500N, and (d) was deformed at 3600N.

From the above, the housing frame (b) created by the same method as the present embodiment using only polycarbonate has a bending strength twice that of the frame (c) created by conventional injection molding. Therefore, it was shown that the composition density of the raw material is increased by the manufacturing method according to the present embodiment, and the strength is improved as compared with the conventional synthetic resin frame material.
In particular, since the housing frame (a) according to the present embodiment includes carbon fiber in the polycarbonate resin, the toughness and elasticity of the frame material are further improved, and an aluminum frame material ( It was shown to have a rigidity comparable to d).

Further, as shown in FIG. 2, in the storage body frame 40 according to the present embodiment, as described above, the mold raw material in the molten state is uniformly formed from the eight resin injection holes. After being injected into the mold, nitrogen gas is injected into the mold in a uniform state from the eight gas injection holes, so that the cavities 43, 44, and 49 are uniform in the inner portion of the mold raw material. Formed. Therefore, the raw material surfaces of the hollow portions 43, 44, and 49 are uniformly pressed toward the inside of the raw material, and the composition density of the raw material can be increased uniformly.
In addition, since the mold raw material made of resin can be cooled uniformly inside the mold, it is possible to prevent “warping” of the frame material resulting from uneven cooling temperature as a whole, and “warping” that occurs in the mold manufacturing process. It is possible to avoid a situation of poor bonding between the frame materials derived from "."

  In addition, the total time of the “primary pressure-holding step” S14, “secondary pressure-holding step” S15, and “third pressure-holding step” S16 according to the present embodiment is 60 seconds, which is a conventional injection molding. Even when the pressure holding time is 40 to 50 seconds, it is possible to prevent a situation in which the production efficiency is reduced.

Further, in the storage body frame 40 according to the present embodiment, since the storage body frame 40 is formed of polycarbonate which is a thermoplastic synthetic resin, it is more than the aluminum frame in the conventional hard type suitcase. The weight of the suitcase as a whole is also light and easy for the user to handle.
Furthermore, in the storage body frame 40 according to the present embodiment, since the hollow portions 43, 44, 49 of nitrogen gas are formed inside in the entire length direction, the bending strength is improved. And lighter.

  In the present embodiment, the case body frame according to the present invention has been described as an example of manufacturing a frame material for a suitcase, but the present invention is not limited to the above embodiment, and other types of hard case type If it is a bag, it is applicable also to an attache case etc., for example. Furthermore, the present invention can be widely applied as an alternative to various storage bodies (for example, musical instrument cases, photographing equipment storage cases, etc.) having an aluminum frame material.

Since the present invention can be widely applied when manufacturing a frame material for a storage body, it has industrial applicability.

S10 Mold raw material production process S11 Mold clamping process S12 Injection process S13 Nitrogen gas supply process S14 Primary pressure holding process S15 Primary nitrogen gas pressure increasing process S16 Secondary pressure holding process S17 Secondary nitrogen gas pressure increasing process S18 Third Next pressure holding step S19 Mold opening step 40 Housing frame 41 Main body side frame 41a Main frame portion 41b Subframe portion 41c Flange portion 41d Groove opening 41e Groove portion 42 Cover side frame 42a Main frame portion 42b Flange portion 42c Groove opening portion 42d Groove part 43 Cavity part 44 Cavity part 45 Locking ridge 46 Locking ridge 47 Locking ridge 49 Cavity part 50 Suitcase (housing body)
51 Main body side shell 51a Peripheral part 52 Lid side shell 52a Peripheral part 53 Caster 54 Upper surface part 55 Key lock part 56 Handle fixing part 57 Projection part

Claims (4)

A storage body comprising a pair of box-shaped main body side shell and lid side shell, and injection molding a frame of a storage body having a main body side frame and a lid side frame fixed to the opening edge of the main body side shell and the lid side shell A method of manufacturing a frame,
Injecting a molten polycarbonate raw material containing carbon fibers cut to a predetermined size into a mold, and injecting a gas into the mold filled with the raw material at a pressure of 3 MPa , into the molten raw material forming a cavity, a step of pressure holding the pressure of 25 seconds the 3MPa after injecting the gas begins to solidify by cooling the raw surface of the cavity, the raw material surface of the cavity is solidified After starting, the gas is pressurized to 10 MPa and injected, and the raw material surface of the cavity that has started to solidify is pressurized toward the inside of the raw material; and after the gas is pressurized and injected, 15 seconds a method of enhancing a composition density of said raw material by applying holding pressure of the 10 MPa, and injected to boost the gas to a pressure of 15 MPa, the air Enhanced and further steps of pressurizing toward the raw surface of the parts inside the raw material, the composition density of the raw material by holding pressure to the pressure of 20 seconds the 15MPa after injection by boosting the gas, made of aluminum And a step of providing rigidity comparable to that of the frame.   The method of manufacturing a storage body frame according to claim 1, wherein the gas is nitrogen gas.   The method for manufacturing a storage body frame according to claim 1, wherein the mold is provided with gas injection holes at predetermined intervals. The method for manufacturing a storage body frame according to any one of claims 1 to 3, wherein the storage body is a suitcase.