JP7709296B2 - hollow structure - Google Patents

Description

The present invention relates to a hollow structure.

In the fields of office furniture, stationery, and industrial equipment, products that use hollow frames as components are known. Generally, molded products made of metal materials such as iron-based materials have been used as hollow structures. However, in order to increase the operating speed and reduce the size of hollow structures such as hollow frames, they are being made into molded products made of resin materials to reduce their weight.

For example, Patent Document 1 discloses a technology that reduces weight by using a link structure made of fiber-reinforced plastic.

JP 2009-195998 A

The fiber-reinforced plastic link structure described in Patent Document 1 is a composite body in which the fiber-reinforced plastic and the metal mounting seat are joined by an adhesive such as a urethane adhesive or an epoxy adhesive, or by a joining method that combines the above adhesives with mechanical fastening, and therefore the manufacturing process is complicated. In addition, there is a concern that the joint between the fiber-reinforced plastic and the metal mounting seat may be destroyed when transmitting torque from a drive source (e.g., a drive motor).

The present invention was made in consideration of the above circumstances, and aims to provide a hollow structure that is lightweight and reduces the risk of damage to the connection parts with driving sources such as motors and other structures.

According to the present invention,
[1]
A hollow structural body;
a joint portion provided in the hollow structure body and having a central opening;
A hollow structure is provided in which, in a fastening through hole provided in the joint portion, when the hollow structure main body is present in the opening direction of the through hole, the hollow structure has a recess extending from the joint portion in the opening direction so as to cylindrically surround the through hole.
[2]
The hollow structure body is
a connecting portion that extends integrally with the joint portion and changes an extending direction from an opening direction of the central opening to a direction different from the opening direction;
An extension portion extending in the extension direction different from the opening direction;
having
The hollow structure according to the above-mentioned [1] is provided, in which the joint portion and the connection portion are integrally configured at the boundary between the connection portion and the extension portion.
[3]
The hollow structure according to the above-mentioned [1] or [2] is provided, wherein the hollow structure body has a width narrower than an outer diameter of the joint portion.
[4]
The hollow structure body may have a region that gradually widens and extends from the joint portion.
[5]
The hollow structure body may have a region that gradually narrows from the joint portion.
[6]
The hollow structure according to any one of the above items [1] to [5] is provided, in which a collar is provided in the through hole of the joint portion.
[7]
The hollow structure according to any one of the above items [1] to [6] is provided, in which a reinforcing member is provided on the joint surface of the joint portion.
[8]
The hollow structure according to any one of the above items [1] to [7], wherein the hollow structure body and the joint portion are injection-molded articles made of a resin composition, is provided.
[9]
The hollow structure according to any one of the above items [1] to [7], wherein the hollow structure body and the joint portion are cast products of a metal material.

The present invention reduces the risk of damage to the connection parts between the drive source such as a motor and other structures, and provides a lightweight hollow structure.

FIG. 2 is a perspective view showing a schematic view of a part of the structure of a hollow structure according to the present embodiment. FIG. 2 is a plan view showing a schematic view of a part of the structure of the hollow structure according to the present embodiment. FIG. 2 is a front view showing a schematic view of a part of the structure of the hollow structure according to the present embodiment. FIG. 2 is a side view showing a schematic view of a part of the structure of the hollow structure according to the present embodiment. FIG. 3 is a side view showing a schematic view of a part of the structure of the hollow structure according to the present embodiment, the view corresponding to the view seen from the arrow A1 in FIG. 2. 3 is a cross-sectional view taken along line A2-A2 of FIG. 2 according to the present embodiment. 4 is a cross-sectional view taken along line A3-A3 of FIG. 3 according to the present embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that in all drawings, similar components are given the same reference numerals and descriptions will be omitted as appropriate. Also, the drawings are schematic and do not correspond to the actual dimensional ratios.

Figure 1 is a perspective view showing a schematic example of the structure of a hollow structure 1 according to this embodiment. Figure 2 is a plan view of the hollow structure 1. Figure 3 is a front view of the hollow structure 1. Figure 4 is a side view of the hollow structure 1. Figure 5 is a view corresponding to the view seen from the arrow A1 in Figure 2. Figure 6 is a cross-sectional view taken along the line A2-A2 in Figure 2. Figure 7 is a cross-sectional view taken along the line A3-A3 in Figure 3.

<Outline of hollow structure 1>
The hollow structure 1 includes a hollow structure body 10 and a joint portion 50 provided at least on one end of the hollow structure body 10. The hollow structure 1 is used for products in the fields of office furniture, stationery, and industrial equipment. The hollow structure 1 is an injection molded product made of a resin composition or a casting made of a metal material, and the hollow structure body 10 and the joint portion 50 are integrally provided. In this embodiment, as shown in Figs. 2 and 3, the joint portion 50 is provided at the left end of the hollow structure body 10.

<Hollow structural body 10>
The hollow structural body 10 has an extension portion 11 and a connection portion 20 provided at one end of the extension portion 11. The connection portion 20 changes the extension direction of the extension portion 11 and connects to a joint portion 50. The extension portion 11 and the connection portion 20 are molded in a substantially seamless manner (i.e., without any seams).

<Extending portion 11>
The extension 11 is a hollow body (hollow frame) having the same diameter and extending linearly to a predetermined length in a cylindrical shape. The thickness of the extension 11 is determined by the required mechanical strength and the material used (e.g., a resin composition or an aluminum alloy).

The shape of the extension 11 is not particularly limited as long as it is a structure capable of forming a hollow frame. The extension direction (i.e., axis) may be straight or curved. The cross-sectional shape of the extension 11 in the width direction (direction perpendicular to the extension direction) may be the same or different over the entire region in the extension direction, and may be, for example, a circle, an ellipse, an oval, a semicircle, or a rectangle.
In addition, the extension portion 11 is not limited to a configuration in which the outer diameter of the extension portion 11 is the same, and may have a region in which the extension portion 11 extends gradually wider or narrower. In other words, the size of the cross-sectional shape may change.
From the viewpoints of the mechanical strength of the hollow structure 1, ease of manufacture, and resistance to stress applied in the short direction, the cross-sectional shape of the extension 11 is preferably circular, elliptical, or rectangular.

<Connection portion 20>
The connecting portion 20 has a substantially cylindrical shape and has a function of changing the extension direction in a predetermined direction. In this embodiment, the opening direction of the joint opening 53 of the joint portion 50 is changed by 90 degrees. For example, referring to FIG. 3, the opening of the joint opening 53 is in the upward direction, but the direction of the extension portion 11, i.e., the extension direction, is changed to the horizontal direction (to the right in FIG. 3) by the connecting portion 20. The direction (angle) of the change is not limited to 90 degrees (i.e., horizontal). For example, the angle may be changed to an angle (e.g., 45 degrees) that is diagonally upward in FIG. 3, or to a downward direction by rotating 180 degrees. In addition, when assuming injection molding of a resin composition or molding by casting of an aluminum alloy or the like, the change angle is preferably within 90 degrees in consideration of removal from a mold.
The shape of the connection portion 20 may be various shapes, similar to the extending portion 11. However, from the viewpoint of mechanical strength (particularly suppression of stress concentration) and ease of manufacture, it is preferable that the shape of the connection portion 20 is substantially the same as or continuous with the shape of the extending portion 11.

<Joint portion 50>
As shown in the plan view of Fig. 2, the joint part 50 is provided in an annular shape so as to protrude a predetermined width outside the connection part 20 in a top view. In other words, it can be said that the hollow structure body 10 has a width narrower than the outer diameter of the joint part 50. Note that a part of the joint part 50 (a part of the right side in Fig. 2) is covered by the connection part 20 and the extension part 11.

The joint portion 50 is provided with a plurality of through holes 55, 56, 57 that penetrate the joint surface 51 and the joint back surface 52. Here, the through holes 55, 56, 57 are provided at a total of 12 locations evenly spaced apart in the circumferential direction. The through holes 55, 56, 57 are used for connecting to a driving source such as a motor or other structures (hereinafter referred to as "other structures"). The through holes 55, 56, 57 may be provided with, for example, metal collars.

When the connection part 20 or the hollow structure body 10 of the extension part 11 is present in the through holes 55, 56, 57 of the joint part 50 in the opening direction (here, upward direction) of the through holes 55, 56, 57, there is a recess (semi-cylindrical recess 21 or cylindrical recess 22) that extends from the joint surface 51 of the joint part 50 in the opening direction (here, upward direction) so as to cylindrically surround the through holes 56, 57.

For the two through holes 56 provided near the outer boundary of the connection part 20, a semi-cylindrical recess 21 is provided in a concave shape toward the opening direction of the through holes 56 so as to cover the periphery of the two through holes 56 in a semi-cylindrical shape. In other words, the semi-cylindrical recess 21 is provided so as to open a part of the connection part 20 toward the opening direction of the through holes 56.

This configuration ensures that the through hole 56 in the joint part 50 can be used reliably even if it is in a position hidden by the connection part 20, and that the joint part 50 can be reliably fastened to other structures.

The two through holes 57 provided in the area that completely overlaps the connection part 20 are surrounded by a cylindrical recess 22 that is recessed toward the opening direction of the through holes 57 so as to cylindrically cover the periphery of the two through holes 57. In other words, the cylindrical recess 22 is provided so as to open a part of the connection part 20 toward the opening direction of the through holes 57.

With this configuration, even if the through hole 57 provided in the joint part 50 is in a position hidden by the connection part 20, it can be used reliably, and fastening to other structures at the joint part 50 can be performed reliably. Also, as shown in Figures 5 and 7, the two cylindrical recesses 22 are spaced apart, and the interior of the connection part 20 and the interior of the extension part 11 are connected between them, so that sufficient space can be secured even when wiring electric wires or the like inside.

The joint opening 53 of the joint portion 50 is continuous with the hollow structures of the connection portion 20 and the extension portion 11 , allowing cables such as power lines and signal lines to be passed inside the hollow structure 1 .
If necessary, a reinforcing member such as a metal plate may be attached to the joint back surface 52 (or joint front surface 51) of the joint portion 50. By providing a reinforcing member, it is possible to prevent the resin member from being broken by the tightening torque acting when fastening the hollow structure 1 to another structure, or from being loosened by creep. Examples of the metal plate include aluminum alloys, titanium alloys, copper alloys, magnesium alloys, stainless steel, etc. As a method for attaching the metal plate to the joint back surface 52, for example, a method of insert molding a thermoplastic resin into the metal plate when molding the hollow structure 1 can be used.

<Material of Hollow Structure 1>
The hollow structural body 1 is, for example, an injection molded article made of a resin composition or a casting made of a metal material.

When the resin composition is a thermoplastic resin, the hollow structure 1 can be molded, for example, by injection molding. When the metal material is an aluminum alloy, the hollow structure 1 can be molded, for example, by aluminum die casting.
With this configuration, it is possible to realize a hollow structure 1 that is lightweight and has a desired strength. In addition, since the hollow structure 1 is integrally molded, the risk of breakage can be reduced compared to hollow structures with other configurations that use adhesives or the like.

Examples of aluminum alloys that can pass through a narrow gate with high fluidity include aluminum alloys for die casting, such as ADC1, ADC3, ADC5, ADC6, ADC10, ADC10Z, ADC12, and ADC12Z.
When an aluminum alloy is used, the hollow structure 1 can be manufactured under known conditions using a known die-casting machine having, for example, a mold in which a cavity is formed, an injection sleeve formed in an approximately cylindrical shape so as to have an internal space and communicating with the cavity at one end thereof, and a plunger tip movably arranged within the injection sleeve.

When a resin composition (thermoplastic resin) is used, known methods can be used as the injection molding method without any restrictions. That is, the hollow structure 1 can be manufactured, for example, by attaching the above-mentioned metal plate as necessary to a cavity formed between a movable mold and a fixed mold, then injecting and filling the cavity with a molten thermoplastic resin or a thermoplastic resin composition, then opening the mold, and removing the slides and inserts used as necessary.

When the hollow structural body 1 is formed by injection molding, the thermoplastic resin as the raw material component is a thermoplastic resin composition that contains a thermoplastic resin as a resin component and further contains additives as necessary.
As the thermoplastic resin, one or more thermoplastic resins selected from polyolefin-based resins, polyester-based resins, polyamide-based resins, polyacetal-based resins, polycarbonate-based resins, fluorine-based resins, polyarylene ether-based resins, polyarylene sulfide-based resins, ABS resins, and polyamide-containing alloys are preferably used because they can improve the mechanical strength of the hollow structure 1.
Among these, polyamide-based resins and polyester-based resins are more preferred, and polyamide-based resins are particularly preferred.As a preferred example of a polyamide-containing alloy, an alloy of a polyamide-based resin and a polyarylene ether-based resin can be given.

Specific examples of polyamide resins include aliphatic polyamides such as nylon 6, nylon 66, nylon 11, and nylon 12, semi-aromatic polyamide resins such as polyhexamethylene terephthalamide and polyhexamethylene isophthalamide, and polyamide resins obtained from metaxylylenediamine. Among these polyamide resins, polyamide resins obtained from metaxylylenediamine and adipic acid are particularly preferred. Such polyamide resins are called nylon MXD6, and are commercially available, for example, from Mitsubishi Engineering Plastics Corporation under the trade name Reny TM.

The thermoplastic resin composition according to this embodiment may contain one or more additives selected from the group consisting of inorganic fillers, flame retardants, flame retardant assistants, heat stabilizers, antioxidants, pigments, weathering agents, plasticizers, dispersants, lubricants, release agents, antistatic agents, impact modifiers, and colorants.

Examples of inorganic fillers include fibrous fillers (glass fiber, carbon fiber, etc.), powdered granular fillers (kaolin, talc, etc.), and plate-like fillers (mica, etc.). Among these fillers, fibrous fillers, particularly glass fiber (chopped strands, etc.), are preferred because of their high strength and rigidity. These fillers can be used alone or in combination of two or more.

These fillers may be used in combination with a sizing agent or a surface treatment agent. Examples of such sizing agents or surface treatment agents include functional compounds. Examples of the functional compounds include epoxy compounds, silane compounds, titanate compounds, etc.
The amount of the inorganic filler in the thermoplastic resin composition is, for example, 0 to 60% by weight, and preferably 5 to 60% by weight.

As the flame retardant, known halogen-based flame retardants such as brominated epoxy polymers and decabromodiphenyl ether, as well as phosphorus-based flame retardants, can be used without restrictions, but when a polyamide resin is used as the base resin and a color tone other than black is required for the molded product, a halogenated bisimide can be used as an example of a suitable flame retardant. When a flame retardant is used, the content is, for example, 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, per 100 parts by mass of the thermoplastic resin composition.

In this embodiment, a general colorant can be blended with the resin. Examples of black colorants (black pigments) used in this embodiment include carbon black, graphite, titanium black, black iron oxide, and the like. Of these, carbon black is particularly desirable in terms of dispersibility, color development, and cost. The black pigments can be used alone or in combination of two or more types.

Non-black colorants include inorganic pigments and organic pigments other than the black pigments described above. These non-black colorants can be used alone or in combination of two or more. Examples of non-black pigments include white pigments (e.g., calcium carbonate, titanium oxide, zinc oxide, zinc sulfide, etc.), yellow pigments (e.g., cadmium yellow, yellow lead, titanium yellow, zinc chromate, yellow ocher, yellow iron oxide, etc.), red pigments (e.g., red pigments, amber, red iron oxide, cadmium red, etc.), blue pigments (e.g., Prussian blue, ultramarine, cobalt blue, etc.), green pigments (e.g., chrome green, etc.), etc.

Examples of organic pigments include azo pigments, azomethine pigments, methine pigments, indanthrone pigments, anthraquinone pigments, pyranthrone pigments, flavanthrone pigments, benzenethrone pigments, phthalocyanine pigments, quinophthalone pigments, perylene pigments, perinone pigments, dioxazine pigments, thioindigo pigments,
Examples of the isoindolinone type, the isoindoline type, the pyrrule-pyrrole type, the quinacridone type, and the like are mentioned.

The amount of the non-black colorant is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 18 parts by mass, and even more preferably 0.5 to 15 parts by mass per 100 parts by mass of the thermoplastic resin composition.

In addition to the inorganic filler, flame retardant, and colorant, the thermoplastic resin composition according to this embodiment can contain other additives within a range that does not impair the effects of the present invention. Examples of various additives include heat stabilizers such as copper-based heat stabilizers and phosphorus-based heat stabilizers, antioxidants such as hindered phenol-based antioxidants, release agents, weather resistance improvers, nucleating agents, foaming agents, impact resistance improvers, lubricants, plasticizers, and flow improvers. When other additives are used in combination, the amount of the additives is, for example, 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, per 100 parts by mass of the resin composition.

The above describes the embodiments of the present invention with reference to the drawings, but these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

The features of this embodiment are summarized as follows.
(1) The hollow structure 1 of this embodiment is
A hollow structural body 10;
A joint portion 50 provided in the hollow structure body 10 and having a central opening (joint opening 53);
In the through holes 55, 56, and 57 for fastening of the joint portion 50, when the hollow structure main body 10 is present in the opening direction of the through holes 55, 56, and 57 (here, the through holes 56 and 57), the joint portion 50 has a recess (semi-cylindrical recess 21, cylindrical recess 22) extending in the opening direction (upward in the figure) so as to cylindrically surround the through holes 56 and 57.
That is, as shown in Figure 2, when viewed from above, when the through holes 56, 57 overlap with the hollow structure main body 10, a cylindrical frame (here, a semi-cylindrical recess 21, a cylindrical recess 22) is provided from the top to the joint part 50.
Even if the through holes 56, 57 provided in the joint portion 50 are located in a position hidden by the hollow structure main body 10 (here, the connection portion 20), they can be reliably utilized, and fastening to other structures at the joint portion 50 can be reliably performed.
(2) The hollow structure body 10 is
a connecting portion 20 that extends integrally with the joint portion 50 and changes its extending direction from an opening direction (here, an upward direction) of the central opening (joint opening 53) to a direction different from the opening direction (here, a horizontal direction);
An extension portion 11 extending in the extension direction different from the opening direction;
having
At the boundary between the connecting portion 20 and the extending portion 11, the joint portion 50 and the connecting portion 20 are integrally formed.
Even if the orientation of the hollow structure changes midway, the hollow structure is constructed seamlessly and integrally, so that stress concentration can be suppressed in the area where the orientation of the hollow structure changes.
(3) The hollow structure body 10 may have a width narrower than the outer diameter of the joint portion 50 .
(4) The hollow structural body 10 may have a region that gradually widens and extends from the joint portion 50. In other words, the hollow structural body 10 is tapered toward the base side (joint 50 side).
(5) The hollow structural body 10 may have a region that gradually narrows from the joint portion 50. That is, the hollow structural body 10 is tapered so that the base side (joint 50 side) becomes wider.
(6) Collars are provided in the through holes 55, 56, 57 of the joint portion 50. Collars may be provided in all of the through holes 55, 56, 57 or in some of the through holes 55, 56, 57.
(7) A reinforcing member may be provided on the joint surface (joint back surface 52) of the joint portion 50.
(8) The hollow structure body 10 and the joint portion 50 may be injection molded articles made of a resin composition. This makes it possible to realize a hollow structure 1 that is lightweight and has a desired strength.
(9) The hollow structure body 10 and the joint portion 50 may be cast products of a metal material. This makes it possible to realize a hollow structure 1 that is lightweight and has a desired strength.

REFERENCE SIGNS LIST 1 Hollow structure 10 Hollow structure body 11 Extension portion 20 Connection portion 21 Semi-cylindrical recess 22 Cylindrical recess 50 Joint portion 51 Joint surface 52 Joint back surface 53 Joint openings 55, 56, 57 Through hole

Claims (8)

A hollow structural body;
a joint portion provided in the hollow structure body and having a central opening;
a fastening through hole provided in the joint portion has a recess extending from the joint portion in an opening direction so as to cylindrically surround the through hole when the hollow structure body is present in an opening direction of the through hole,
The hollow structural body is
a connecting portion that extends integrally with the joint portion and changes an extending direction from an opening direction of the central opening to a direction different from the opening direction;
An extension portion extending in the extension direction different from the opening direction;
having
The joint portion and the connection portion are integrally formed at a boundary between the connection portion and the extension portion,
The recess has a semi-cylindrical recess and a cylindrical recess in the connection portion,
the semi-cylindrical recess is provided in a concave shape toward an opening direction of the first through hole so as to cover a periphery of the first through hole, the first through hole being provided at an outer boundary of the connection portion, in a semi-cylindrical shape;
A hollow structure, wherein the cylindrical recess cylindrically covers the periphery of a second through hole which is different from the first through hole and is provided at a location where the semi-cylindrical recess is not present . The hollow structure according to claim 1 , wherein the hollow structure body has a width narrower than an outer diameter of the joint portion. The hollow structure according to claim 1 or 2 , wherein the hollow structure body has a region that gradually widens and extends from the joint portion. The hollow structure according to claim 1 , wherein the hollow structure body has a region that gradually narrows from the joint portion. The hollow structure according to claim 1 , wherein the through hole of the joint portion is provided with a collar. The hollow structure according to claim 1 , wherein a reinforcing member is provided on a joint surface of the joint portion. 7. The hollow structure according to claim 1 , wherein the hollow structure body and the joint portion are injection molded articles made of a resin composition. 7. The hollow structure according to claim 1, wherein the hollow structure body and the joint portion are cast products of a metal material.