JP7367590B2 - Top plate for X-ray imaging equipment - Google Patents

Description

The present invention relates to a top plate suitable for medical X-ray equipment such as an X-ray imaging device and a CT scanner.

A top plate for an X-ray imaging device is required to have good X-ray transparency and high bending strength so that it does not interfere with imaging even when a load of 1 ton is evenly distributed on the top surface.

For example, Japanese Patent Application Laid-Open No. 60-236633 discloses an X-ray transparent top plate obtained by alternately laminating unidirectionally aligned prepreg sheets made of carbon fiber and epoxy resin as a top plate for such an X-ray imaging device. Although an excellent top plate for X-ray photography made of a thin CFRP plate has been disclosed, it is not strong enough.

Furthermore, Japanese Patent Application Laid-open No. 2004-216021 discloses that a high-strength top plate for an X-ray imaging device can be obtained by reinforcing it with a fabric prepreg, but in recent years, clearer X-ray images have been improved. Due to the requirement, the cross stitch of the fabric becomes uneven, so improvements were desired.

Japanese Patent Application Publication No. 60-236633 Japanese Patent Application Publication No. 2004-216021

An object of the present invention is to provide a top plate for an X-ray imaging apparatus that has uniform X-ray transparency, improves unevenness in X-ray images, and has excellent bending strength.

In order to solve this problem, the present invention employs the following means.
[1] Multiple layers (number of layers: N layers, N is a natural number of 2 or more) of woven prepreg [B], which is a reinforcing fiber fabric impregnated with a thermosetting resin, are laminated on both sides of a core material made of resin foam. A top plate for an X-ray imaging device having a sandwich structure in which a skin is arranged and cured by heating,
The reinforced fiber fabric has a warp width Wv (mm), a weft width Wh (mm), a warp gap Gv (mm), and a weft gap Gh (mm),
The fabric prepreg [B] is laminated by shifting the warp by Wv/N (mm) and the weft by Wh/N (mm) in layer units, and satisfying the following formulas (1) and (2). Features: Top plate for X-ray imaging equipment.
Wv/N×(N-1)≧Gv...(1)
Wh/N×(N-1)≧Gh...(2)
[2] The top plate for an X-ray imaging apparatus according to [1], wherein the fabric prepreg [B] is sequentially stacked while being shifted in a certain direction layer by layer.
[3] The top plate for an X-ray imaging device according to [1] or [2], characterized in that a textile prepreg [B ₁ ] having the highest tensile strength is arranged on the top surface of the top plate for an X-ray imaging device. .
[4] The X-ray imaging device according to any one of [1] to [3], characterized in that a fabric prepreg [B ₂ ] having the highest compressive strength is arranged on the lowermost surface of the top plate for the X-ray imaging device. Top plate for use.
[5] As the fabric prepreg [B], a fabric prepreg [B ₀ ] that does not have at least one of the warp gap Gv (mm) or the weft gap Gh (mm) is used [1 ] to [4]. The top plate for an X-ray imaging device according to any one of [4].
[6] Any one of [1] to [5], wherein the thermosetting resin is one or more thermosetting resins selected from epoxy resins, unsaturated polyester resins, and vinyl ester resins. Top plate for the X-ray imaging device described.
[7] The top plate for an X-ray imaging device according to any one of [1] to [6], wherein the reinforcing fiber fabric is a fabric selected from plain weave, twill weave, and satin weave.

According to the present invention, it is possible to provide a top plate for an X-ray imaging device that has uniform X-ray transparency, improves unevenness in X-ray images, and has excellent bending strength.

FIG. 1 is a schematic perspective view of a top plate for an X-ray imaging apparatus according to an embodiment of the present invention. FIG. 7 is a schematic top view showing a laminated state of the skin on the top surface side of the top plate when the cross stitches of the fabric overlap. When laminating N layers of woven prepreg [B], the laminated state of the skin on the top surface side of the top plate, which is laminated by shifting Wv/N (mm) and Wh/N (mm) so that the cross stitches do not overlap, is as follows. FIG. 2 is a longitudinal section of the top plate shown in FIG. 1. FIG. 2 is a schematic diagram showing a method for testing the strength of a top plate.

The top plate for an X-ray imaging device of the present invention has multiple layers (number of layers: N layers, N is a natural number of 2 or more) This is a top plate for an X-ray imaging device having a sandwich structure in which laminated skins are arranged and cured by heating, and the reinforcing fiber fabric has a warp width Wv (mm) and a weft width Wh (mm). ), the warp gap Gv (mm), and the weft gap Gh (mm), and the fabric prepreg [B] has a warp gap of Wv/N (mm) and a weft gap of Wh/N (mm) in layer units. This is a top plate for an X-ray imaging apparatus, characterized in that the top plate is stacked by shifting each other by ) and satisfies the following formulas (1) and (2).
Wv/N×(N-1)≧Gv...(1)
Wh/N×(N-1)≧Gh...(2)

FIG. 1 shows a schematic diagram of a top plate for an X-ray imaging apparatus according to an embodiment of the present invention. The top plate for an X-ray imaging apparatus has a sandwich structure of a core material 1 and a skin 2 provided so as to cover the core material 1. The skin 2 includes an upper skin 2a, a lower skin 2b, a right skin 2c, and a left skin 2d. The skin 2 is not limited to covering the core material 1, and may be provided only on the upper and lower surfaces of the core material 1. A separately molded skin and core material may be bonded together.

It is preferable that the core material 1 made of a resin foam in the present invention has a density as low as possible within a range that satisfies high strength and high rigidity. As the material of the resin foam, it is preferable to use hard plastic foam such as polyurethane foam, polystyrene foam, polyvinyl chloride foam, acrylic foam, polymethacrylimide foam, cellulose acetate foam, epoxy foam, and phenol foam.

The textile prepreg [B] in the present invention has a structure in which a thermosetting resin is contained in a reinforcing fiber textile. As the reinforcing fiber of the reinforcing fiber fabric, at least one kind of carbon fiber (including graphite fiber), aramid fiber, high-strength polyethylene fiber, glass fiber, boron fiber, etc. can be used. Among these, it is preferable to use carbon fiber, which has excellent radiation transparency. Note that these reinforcing fibers can be used in the form of woven fabrics such as plain weave, satin weave, twill weave, and blind weave. Examples of thermosetting resins include thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, and polyimide resins, as well as ABS resins, nylon resins, polyether ether ketone resins, and polyolefin resins. Thermoplastic resin can be used. Among them, it is preferable to use epoxy resin or vinyl ester resin in consideration of adhesiveness with carbon fibers and moldability. Furthermore, the thermosetting resin may contain various additives, fillers, colorants, and the like.

The skin 2 of the present invention, which is made by laminating multiple layers of woven prepreg (number of layers: N layers, N is a natural number of 2 or more), depends on the purpose, the size of the top plate, and the type, characteristics, form, etc. of the reinforcing fibers used. However, the number of layers is about 2 to 6.

In the present invention, the reinforced fiber fabric has a warp width Wv (mm), a weft width Wh (mm), a warp gap Gv (mm), and a weft gap Gh (mm), and the woven fabric prepreg [B] is It is important to stack the warp yarns by Wv/N (mm) and the weft yarns by Wh/N (mm) in units of layers, and to satisfy the following formulas (1) and (2).
Wv/N×(N-1)≧Gv...(1)
Wh/N×(N-1)≧Gh...(2)

If the warp is shifted by Wv/N (mm) and the weft is shifted by Wh/N (mm) in layer units, then when N layers are stacked to form skin 2, the gap will be Gv (mm) or Gh (mm). ) can be covered without any gaps. Here, it is preferable to sequentially laminate the woven fabric prepreg [B] while shifting the layers in a certain direction. By shifting in a certain direction, the overlapping areas and exposed areas of overlapping warps and wefts can be made equal. Even when X-rays are irradiated during X-ray photography, overlapping unevenness due to lamination is less likely to occur, making it easier to obtain more uniform and clear images.

Here, if Wv/N×(N-1)<Gv or Wh/N×(N-1)<Gh, as shown in FIG. Even if the skin 2 is made by laminating the skin 2 by shifting the units, a part of the gap Gv (mm) or Gh (mm) of the woven prepreg [B] placed directly above the core material 1 may overlap with other laminated layers. A void portion that is not covered with the fabric prepreg [B] remains. Therefore, when an X-ray image is taken using a top plate for an X-ray imaging device obtained by heat compression molding, as shown in Figure 2(b), Due to the difference in the amount, unevenness may occur along the cross-grain of the reinforcing fiber fabric, and a clear image may not be obtained.

On the other hand, when laminated so that Wv/N×(N-1)≧Gv and Wh/N×(N-1)≧Gh are satisfied, as shown in FIG. The gaps Gv (mm) or Gh (mm) of the fabric prepregs [B] arranged in the fabric prepregs [B] are covered with the other laminated fabric prepregs [B], and voids caused by the gaps no longer occur. Therefore, when an X-ray image is taken using a top plate for an X-ray imaging device obtained by heat compression molding, the portion where the reinforcing fibers are present is uniformly irradiated with X-rays, as shown in Figure 3(b). Therefore, uniform images can be obtained without unevenness in the image along the cross-grains of the reinforcing fiber fabric.

Moreover, it is also preferable to use, as the textile prepreg [B], a textile prepreg [B ₀ ] that does not have at least one of the warp gap Gv (mm) or the weft gap Gh (mm). By using such a woven prepreg [B ₀ ], it is possible to strengthen the reinforcement during X-ray imaging without shifting the warp by Wv/N (mm) or the weft by Wh/N (mm) in each layer during lamination. A uniform image can be obtained without unevenness along the cross-grain of the fiber fabric.

Further, in the present invention, it is preferable to arrange the fabric prepreg [B ₁ ] having the highest tensile strength on the uppermost surface of the top plate for the X-ray imaging device. Furthermore, it is preferable to arrange the fabric prepreg [B ₂ ] having the highest compressive strength on the lowermost surface of the top plate for the X-ray imaging device.

As shown in FIG. 4, the skin 2 includes a plurality of layers (five layers in FIG. 4) of fabric prepregs laminated in both the upper skin 2a and the lower skin 2b. That is, the upper skin 2a is made of fabric prepregs 2a ₁ , 2a ₂ , 2a ₃ , 2a ₄ , 2a ₅ in order from the core material 1 side, and the lower skin 2b is made of fabric prepregs _{2b 1} , 2b ₂ in order from the core material 1 side. 2b ₃ , 2b ₄ , and 2b ₅ are stacked.

The top plate for the X-ray imaging device is installed as a cantilever beam as shown in Figure 5, and when the subject stands on the top of the top plate, an evenly distributed vertically downward load is applied, as shown in Figure 4. A bending moment occurs. When a bending moment is applied to the top plate, the upper skin 2a becomes the tensile side (convex side). A higher tensile strength acts on the textile prepreg layer 2a ₂ located on the outside of the textile prepreg layer 2a ₁ than on the textile prepreg layer 2a ₁ located closest to the core material 1, so that the uppermost surface side It is preferable that the fabric prepreg layer 2a ₅ is a fabric prepreg layer having the highest tensile strength among the laminated fabric prepreg layers.

On the other hand, when a bending moment is applied to the top plate, the lower skin 2b becomes compressed (concave). Since higher compressive strength acts on the fabric prepreg layer 2b ₂ located on the outside of the fabric prepreg layer 2b ₁ than on the fabric prepreg layer 2b ₁ located closest to the core material 1, the lowermost side It is preferable that the textile prepreg layer _2b5 located is a textile prepreg layer having the highest compressive strength among the laminated textile prepreg layers. In this way, in the present invention, when a bending moment is applied to the top plate, when looking at the top plate as a whole, tensile stress is applied to the upper skin 2a, and compressive stress is applied to the lower skin 2b. Therefore, by taking the occurrence of such stress into consideration and disposing a woven prepreg layer, high strength can be efficiently achieved.

Further, although the effect is reduced, only the upper skin 2a may have the above-described structure, or only the lower skin 2b may have the above-described structure.

The top plate for an X-ray imaging device of the present invention can be used, for example, in an X-ray CT device.

1: Core material 2: Skin 2a: Upper skin 2b: Lower skin 2c: Right skin 2d: Left skin 2a ₁ to 2a ₅ : Textile prepreg 2b ₁ to 2b ₅ : Textile prepreg

Claims (7)

A skin made by laminating multiple layers (number of layers: N layers, N is a natural number of 2 or more) of woven prepreg [B], which is a reinforced fiber fabric impregnated with a thermosetting resin, on both sides of a core material made of resin foam. A top plate for an X-ray imaging device having a sandwich structure, which is arranged and heated to harden,
The reinforced fiber fabric has a warp width Wv (mm), a weft width Wh (mm), a warp gap Gv (mm), and a weft gap Gh (mm),
The fabric prepreg [B] is laminated by shifting the warp by Wv/N (mm) and the weft by Wh/N (mm) in layer units , and satisfying the following formulas (1) and (2). A top plate for an X-ray imaging device.
Wv/N×(N-1)≧Gv...(1)
Wh/N×(N-1)≧Gh...(2) The top plate for an X-ray imaging apparatus according to claim 1, wherein the fabric prepreg [B] is sequentially laminated while being shifted in a certain direction layer by layer. The top plate for an X-ray imaging device according to claim 1 or 2, wherein a fabric prepreg [B1] having the highest tensile strength is disposed on the top surface of the top plate for an X-ray imaging device. The top plate for an X-ray imaging device according to any one of claims 1 to 3, characterized in that a fabric prepreg [B2] having the highest compressive strength is disposed on the lowermost surface of the top plate for an X-ray imaging device. Claims 1 to 4, characterized in that the fabric prepreg [B] is a fabric prepreg [B0] that does not have at least one of the warp gap Gv (mm) or the weft gap Gh (mm). A top plate for an X-ray imaging device according to any one of the above. X-ray imaging according to any one of claims 1 to 5, characterized in that the thermosetting resin is one or more thermosetting resins selected from epoxy resins, unsaturated polyester resins, and vinyl ester resins. Top plate for equipment. The top plate for an X-ray imaging apparatus according to any one of claims 1 to 6, wherein the reinforcing fiber fabric is a fabric selected from plain weave, twill weave, and satin weave.