JP4333242B2 - Radiation diagnostic equipment top plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a top board suitable for a radiation diagnostic apparatus such as an X-ray imaging apparatus or a CT scanner.
[0002]
[Prior art]
In recent years, the top plate of a radiological diagnostic apparatus such as an X-ray imaging apparatus or a CT scanner has been lengthened so that a wide range of patients placed thereon can be imaged at once, and a patient weighing 200 kg, for example, can be placed thereon. Even when used repeatedly, there is a strong demand for increasing the load resistance so as not to hinder shooting.
[0003]
In general, the normal use state of the top plate is one end fixed to the main body of the radiation diagnostic apparatus or a movable part attached to the main body, and the other end is a cantilever state with a free end. In order to achieve the above, the fixing unit and the other end of the top plate are often supported by a roll attached to the main body side. Many of such top plates are configured as a so-called sandwich structure in which the cross-section has a skin positioned on the surface of the core.
[0004]
Conventionally, a top plate having a cross-sectional shape as shown in FIG. 2 is regarded as a group of two side skins 2b and a lower surface skin 2c, and the top plate has a predetermined material and thickness for each skin. It has been designed with the same structural design to satisfy the strength and rigidity. That is, the side skin 2b is designed to have the same high rigidity as the lower skin 2c.
[0005]
In this case, as shown in FIG. 6A, most of the load applied to the upper surface is not from the low-rigidity core 3, but from the high-rigidity side skin 2b to the lower-surface skin. Since the force is transmitted to 2c, the roll 4 cannot be pressed with a uniform force, and the reaction force of the roll 4 is locally increased at the boundary between the side skin 2b and the bottom skin 2c as shown in FIG. As a result, this portion is strongly pressed.
[0006]
In such a case, since the force pressing the roll 4 acts as a reaction force against the top plate as it is, the boundary portion between the side skin 2b and the bottom skin 2c receives a large force locally from the roll 4 and is used. There was a problem that the part was easily damaged. Further, when the hardness of the roll 4 surface is low, the roll 4 side may be damaged. Such dangers are increasing due to further demands for longer lengths and higher load-bearing values.
[0007]
In order to solve such a problem, Patent Document 1 describes that the side skin 2b and the lower surface skin 2c may be designed with different members to increase the mechanical strength. The purpose is not to cause a large deflection even if a large bending moment acts in the longitudinal direction of the top plate in a cantilever state. If the side skin 2b is designed to have a high rigidity in accordance with this purpose, the above-mentioned is also true. There is a high possibility that the top plate or the roll 4 is damaged by such a mechanism.
[0008]
[Patent Document 1]
Japanese Utility Model Publication No. 5-62208 (Claims 1 and 2)
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems of the conventional top plate, and its object is to provide a top plate for a radiation diagnostic apparatus that has higher strength and is evenly distributed on the roll. To provide.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a top plate for a radiation diagnostic apparatus according to the present invention is a top panel for a radiation diagnostic apparatus in which an outer periphery of a core is surrounded by a skin, wherein the skin includes an upper surface skin, two side skins, The thickness of the side skin is tS, and the thickness of the side skin is tS.
tS <tL
It is characterized by being in the relationship.
[0011]
As shown in FIG. 7A, the thickness of the side skin is made smaller than the thickness of the bottom skin, thereby reducing the rigidity of the side skin and reducing the load transmitted from the side skin to the bottom skin. For this reason, as shown in FIG. 5B, it is possible to reduce the force that strongly presses the roll at the boundary between the side skin and the bottom skin, that is, the reaction force received from the roll.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The contents of the present invention will be described below with reference to the drawings of one embodiment of the present invention.
[0013]
FIG. 1 is a perspective view of the top plate of the present invention having a partially broken portion, and FIGS. 2 to 5 are various specific examples in a longitudinal section of the top plate of FIG.
[0014]
In FIG. 1, the top plate 1 includes a core 3 and a skin 2 provided so as to surround the core 3. The skin 2 is composed of an upper skin 2a, two side skins 2b, and a lower skin 2c, and the thickness of each skin is preferably about 1 to 8 mm from the viewpoint of X-ray transparency. The shape of each skin is that the upper surface skin 2a has a concave curved surface for placing a patient thereon, and the other three surfaces are flat, and the cross-sectional shape of these three skins is generally trapezoidal. It has become.
[0015]
The cross-sectional shape of the top plate that can obtain a great effect by application of the present invention is a shape based on the trapezoid or the rectangle described above, and examples of the cross-sectional shape shown in FIGS. That is, the top plate in FIG. 2 has a flat top skin 2a, and the one in FIG. 3 is similar to that in FIG. 1, but the side skin is composed of two flat surfaces having an obtuse angle. In FIG. 4, a part or the whole of the side skin is a convex curved surface. In FIG. 5, the roller has a rectangular cross section.
[0016]
By the way, as described above, in order to improve the problem of the damage of the boundary between the side skin and the lower skin or the damage of the roll surface at the position opposite to the boundary, the side skin 2b is used under normal use conditions. It is necessary to reduce the load transmitted from the side skin 2b to the lower skin 2c and reduce the force that strongly presses the roll at the boundary between the side skin 2b and the lower skin 2c, that is, the reaction force received from the roll. However, for this purpose, it is necessary to make the thickness of the side skin 2b smaller than the thickness of the lower surface skin 2c. In order to obtain the effect of the present invention sufficiently, it is ½ of the thickness of the lower surface skin 2c. It is preferably 1 or less.
[0017]
Further, in order to reduce the rigidity of the side skin 2b, when the longitudinal elastic modulus of the side skin 2b is ES, 0 degrees and the elastic modulus in the direction (width direction) perpendicular to the longitudinal direction is ES, 90 degrees, The ratio ES, 0 degrees / ES, 90 degrees is
ES, 0 degrees / ES, 90 degrees ≧ 3
It is preferable that the relationship is ES, 0 degrees / ES, 90 degrees ≧ 5.
[0018]
On the other hand, the longitudinal elastic modulus of the side skin 2b and the lower skin 2c is high rigidity so that the bending amount of the free end is within a predetermined range even when a bending moment acts in the longitudinal direction of the cantilevered top plate. It is preferable to design. Moreover, it is preferable that the thickness of the lower skin 2c is specified and designed within a range where a predetermined X-ray transmittance can be obtained. Thus, it is preferable that the skin 2 includes FRP (fiber reinforced plastic) and CFRP (carbon fiber reinforced plastic) having anisotropy so that the longitudinal direction and the width direction can be separately designed to be rigid.
[0019]
The FRP includes a reinforcing fiber and a matrix resin.
[0020]
As the reinforcing fiber, at least one of carbon fiber (including graphite fiber), aramid fiber, high-strength polyethylene fiber, glass fiber, and boron fiber can be used. Most preferably. These reinforcing fibers are used in the form of strands, woven fabrics such as plain weave, satin weave, and twill weave.
[0021]
As matrix resin, thermosetting resin such as epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin, polyimide resin, and thermoplastic resin such as ABS resin, nylon resin, polyether ether ketone resin, polyolefin resin, etc. Can be used. Among these, a combination of carbon fiber and an epoxy resin or vinyl ester resin excellent in adhesiveness with the carbon fiber is preferable.
[0022]
The thickness and elastic modulus of the FRP can be changed depending on the type, characteristics, and form of the reinforcing fiber, the type of the matrix resin, the ratio between the reinforcing fiber and the matrix resin, and the like.
[0023]
The core is like a rigid plastic foam such as polyurethane foam, polystyrene foam, polyvinyl chloride foam, acrylic foam, polymethacrylimide foam, cellulose acetate foam, epoxy foam, phenol foam and the like.
[0024]
The rigid plastic foam preferably has a high elastic modulus of 20 MPa or more. As a result, the load applied to the upper skin is transmitted not only from the side skin but also from the core to the lower skin, so that a large local reaction force generated at the boundary between the side skin and the lower skin is reduced.
[0025]
Although the magnitude | size of the top plate 1 is based also on a use etc., thickness is about 30-70 mm, width is about 200-500 mm, and length exceeds 2,000 mm.
[0026]
Such a top plate is formed by, for example, winding a reinforcing fiber prepreg around a core and heating and pressing to integrally form the core and the skin, or by arranging a reinforcing fiber prepreg on the surface of the core and integrally molding the same. Can be manufactured. A separately molded skin and core may be bonded together.
[0027]
Examples and Comparative Examples
(Example)
A top plate 1 composed of a skin 2 and a core 3 as shown in FIG.
[0028]
The outer dimensions of the top plate 1 are those having an upper skin width of 420 mm and a lower skin width of 180 mm, the upper surface has a curved surface with a radius of 500 mm, the top plate length in the longitudinal direction is 2300 mm, and the maximum thickness is 42 mm.
[0029]
The skin 2 is composed of a plurality of CFRP layers, carbon fiber satin fabric and plain fabric are used as reinforcing fibers, and epoxy resin is used as a matrix resin. However, the type of carbon fiber, the woven density, and the type of matrix resin were selected so that the longitudinal elastic modulus, width elastic modulus, and thickness of the upper skin 2a, lower skin 2c, and side skin 2b were as follows.
[0030]
Top skin:
Longitudinal elastic modulus 80 GPa, width elastic modulus 40 GPa, thickness 1.3 mm
Bottom skin:
Longitudinal elastic modulus 80 GPa, width elastic modulus 40 GPa, thickness 3.6 mm
Side skin:
Longitudinal elastic modulus 120 GPa, width elastic modulus 20 GPa, thickness 1.5 mm
The core 3 was a hard acrylic foam (elastic modulus: 70 MPa) having a thickness of 50 mm, a width of 500 mm, and a length of 2,000 mm. The hard acrylic foam was cut into a predetermined shape by NC processing, and processed so that a block made of an aluminum alloy could be inserted into a portion corresponding to a fixing portion with the radiation diagnostic apparatus main body.
[0031]
The top plate 1 was formed by winding a carbon fiber fabric around the core 3 and impregnating the matrix resin with a vacuum bag, followed by heating and pressing.
[0032]
As shown in FIG. 8, this top plate is attached to a radiation diagnostic apparatus main body 6 including a roll 4 made of stainless steel having a diameter of 65 mm and a length of 250 mm and having a surface covered with high-hardness rubber, and the upper skin 2a is made of steel. The weight was uniformly distributed in the longitudinal direction, 180 kg was equally distributed, and reciprocated back and forth (left and right in the drawing).
[0033]
As a result, it was possible to reciprocate 110,000 times without significant damage at the boundary between the side skin 2b and the bottom skin 2c.
[0034]
(Comparative Example 1)
In the examples, the bottom skin and the side skin are considered as a bottom skin, and the material and thickness used for each skin are in accordance with the conventional design method in which the same design is performed. The elastic modulus and thickness were as follows.
[0035]
Top skin:
Longitudinal elastic modulus 80 MPa, width elastic modulus 40 MPa, thickness 1.3 mm
Bottom skin:
Longitudinal elastic modulus 80 MPa, width elastic modulus 40 MPa, thickness 3.6 mm
Side skin:
Longitudinal elastic modulus 80 MPa, width elastic modulus 40 MPa, thickness 3.6 mm
When this top plate was tested in the same manner as in the example, cracks occurred at the boundary between the side skin and the bottom skin after 20,000 reciprocations, making it impossible to continue the test.
[0036]
(Comparative Example 2)
In the example, the same test as in the example was performed using a low-density polyurethane foam (elastic modulus: 8 MPa) as a core. A crack occurred and the test could not be continued.
[0037]
【The invention's effect】
In the present invention, the side skin and the lower skin are designed separately, and the thickness of the side skin is made smaller than that of the lower skin, or the elastic modulus in the width direction is reduced. Since the load transmitted to the side is reduced, it is possible to reduce the force that strongly presses the roll at the boundary between the side skin and the bottom skin, that is, the reaction force received from the roll. As a result, a uniform reaction force acts from the roll in the width direction of the bottom surface of the top plate. High strength top plate can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view having a partially broken portion of a top plate according to an embodiment of the present invention.
FIG. 2 is another example of the cross-sectional shape of the top plate according to the present invention.
FIG. 3 is another example of the cross-sectional shape of the top plate according to the present invention.
FIG. 4 is another example of the cross-sectional shape of the top plate according to the present invention.
FIG. 5 is another example of the cross-sectional shape of the top plate according to the present invention.
FIG. 6 is a model diagram showing a state of transmission of a load to a roll when a load is applied to a top plate according to a conventional design.
FIG. 7 is a model diagram showing a state of transmission of a load to a roll when a load is applied to the top plate according to the present invention.
FIG. 8 is a model diagram in which a top plate is attached to a radiation diagnostic apparatus.
[Explanation of symbols]
1: Top plate 2: Skin 2a: Upper skin 2b: Side skin 2c: Lower skin 3: Core 4: Roll 5: Movable part 6: Radiation diagnostic apparatus body

Claims (7)

In the top plate for a radiological diagnostic apparatus in which the outer periphery of the core is surrounded by a skin, the skin is composed of an upper skin, two side skins, and a lower skin, and the thickness of the side skin is tS. When the thickness is tL, the thickness tS of the side skin is
tS <tL
A top plate for a radiation diagnostic apparatus, characterized in that: The thickness tS of the side skin is
tS <tL / 2
The top plate for a radiation diagnostic apparatus according to claim 1, wherein: When the longitudinal elastic modulus of the side skin is ES, 0 degrees, and the elastic modulus in the direction perpendicular to the longitudinal direction is ES, 90 degrees, the ratio ES of both, 0 degrees / ES, 90 degrees,
ES, 0 degrees / ES, 90 degrees ≧ 3
The top plate for a radiation diagnostic apparatus according to any one of claims 1 and 2, wherein The top plate for a radiation diagnostic apparatus according to any one of claims 1 to 3, wherein the elastic modulus of the core is 20 MPa or more. The core is a rigid plastic foam such as polyurethane foam, polystyrene foam, polyvinyl chloride foam, acrylic foam, polymethacrylimide foam, cellulose acetate foam, epoxy foam, or phenol foam. A top plate for a radiation diagnostic apparatus according to any one of the above. The top plate for a radiation diagnostic apparatus according to claim 1, wherein the skin contains FRP. The top plate for a radiation diagnostic apparatus according to claim 1, wherein the FRP contains CFRP.

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