JPH11271242A - Internal form observation method for hollow elastic body and deformation test method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly observe the inside surface form of the hollow part of a nonmetallic hollow elastic body such as rubber or synthetic resin by providing the sectional image of the elastic body by use of a computer tomography utilizing non-biological physical characteristic. SOLUTION: An X-ray is projected from an X-ray tube 12 toward an elastic body 18 by an X-ray generating unit 22, and a rotary frame 12 is rotated. The X-ray multidirectionally projected to the elastic body 18 and transmitted by the elastic body 18 is detected as X-ray intensity signal by an X-ray detector 16, and the detection signal is digitized and transferred to a CPU 20. In the CPU 20, a calculation is performed according to an algorithm such as reverse projection and sucessive approximation according to a preset program to reconfigure the image from the resulting multidirectional X-ray transmission data, and the image data is stored in an external memory device 24 using a magnetic memory medium. As occasion demands, the data is displayed as the sectional image of the elastic body 18 so as to be visually confirmable by an external display device 26 such as CRT.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel observation method capable of clearly observing the internal shape of an elastic body having a hollow structure,
The present invention relates to a novel deformation test method capable of measuring a deformed shape of such a hollow elastic body under a load action with high accuracy.

[0002]

BACKGROUND ART An elastic body made of an elastomer material such as rubber or synthetic resin has been used as an anti-vibration connector, an anti-vibration support, a shock absorber, and the like for vehicles such as automobiles, architecture, electric equipment, and the like.
Although it is used in an extremely wide field, such an elastic body may require inspection of the product shape and dimensions in addition to material inspection in order to stably obtain desired performance and the like. . If the amount of deformation due to external load is large,
In addition to the shape before the load input, inspection of the shape at the time of deformation by the load input may be important, especially since the deformed shape has a large effect on load-bearing performance and durability.
The measurement of the deformed shape is often one of important data when designing a product.

[0003] By the way, if the elastic body has a solid structure, it is possible to easily observe and measure the product dimensions and deformed shape only for the outer surface shape of the elastic body. In the case, the shape of the hollow inner surface has a large effect on the performance, etc.
It has to be estimated from the outer surface shape, which makes it difficult to observe and measure the product dimensions and deformed shape of the elastic body with sufficient accuracy.

[0004] Specifically, for example, it has a substantially cylindrical shape provided with a hollow hole penetrating in the axial direction, and is externally mounted on a piston rod of a shock absorber (automobile shock absorber) of an automobile, so as to have an excessively large shock. An excellent bump stopper made of an elastic material such as a rubber elastic body or a polyurethane foam (urethane foam), which is compressed and deformed in the axial direction when a load is input, thereby reducing the feeling of bottoming of the suspension mechanism. In order to obtain cushioning performance and durability, it is important to prevent buckling deformation at the time of load input and to prevent the inner peripheral surface of the hollow hole from interfering with the piston rod. However, it is extremely difficult to recognize the state of buckling deformation and interference with the piston rod in the bump stopper only by external observation, so it is very difficult to grasp the performance and optimize the design. There was.

[0005] In order to deal with such a problem,
It is also conceivable to use an X-ray imaging system such as an X-ray television or an X-ray film, and use a perspective image of the elastic body in one direction obtained by transmitted X-rays in which X-rays are transmitted in one direction. However, in such X-ray fluoroscopic images, it is not always possible to obtain a clear outline, and in particular, the hollow portion surrounded by the same elastic material has a degree of absorption of X-rays substantially in the entire peripheral wall portion. Because they are the same, it is extremely difficult to recognize the outline of the inner peripheral surface of the hollow portion, and satisfactory practicality has not been obtained.

[0006]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a hollow elastic body made of a nonmetallic hollow elastic material such as rubber or synthetic resin. An object of the present invention is to provide a novel observation method capable of clearly observing the inner peripheral surface shape.

Further, the present invention provides a novel deformation test method capable of measuring the shape of the inner peripheral surface of a hollow portion of such a nonmetallic hollow elastic body deformed by the action of an external load with high accuracy. The purpose is also to provide.

[0008]

In order to solve such a problem, a feature of the present invention relating to a method for observing the internal shape of a hollow elastic body is that when observing the internal shape of a nonmetal elastic body having a hollow structure, An object of the present invention is to observe the internal shape of an elastic body by obtaining a cross-sectional image of the elastic body by using a computer tomography method utilizing abiotic physical characteristics.

Further, in order to solve the above-mentioned problems,
A feature of the present invention relating to a deformation test method for a hollow elastic body is a deformation test method for a non-metal elastic body having a hollow structure, wherein a non-living physical property is applied in a state where an external load is applied to the elastic body. An object of the present invention is to measure a deformed shape of the elastic body by using a cross-sectional image of the elastic body obtained by a computer tomography method using characteristics.

[0010] In the method of the present invention, the hollow elastic body to be observed or measured may be any material capable of photographing the shape of the hollow inner surface by computer tomography. The method of the present invention is suitably applied to an elastic body made of a material such as a resin. In addition, as computed tomography, a conventionally known abiotic physical property, such as a substance, is used in consideration of the material and the like of the elastic body so that the hollow inner surface shape of the hollow elastic body can be photographed as clearly as possible. Computed tomography using the absorption characteristics of electromagnetic waves such as X-rays and the resonance characteristics of the magnetic system of atoms,
It is appropriately selected and adopted. Specifically, the computer tomography according to the present invention is, for example, an X-ray computed tomography (X-ray CT) practically used in the medical field.
And magnetic resonance imaging (magnetic resonance imaging) can be carried out using these devices substantially as they are. In particular, when there is a ferromagnetic material or the like in a part, the X-ray CT method is used. Is advantageously employed.

That is, the present invention has newly found that when observing the shape of the hollow inner surface of a nonmetallic elastic body, computed tomography utilizing the physical characteristics of the elastic body can be advantageously employed. Therefore, the cross-sectional shape of the inner surface of the hollow portion, for which a clear cross-sectional shape line could not be obtained in a transmission image of X-rays in one direction, is also calculated according to computed tomography. By storing and accumulating the image data and performing a reorganization process, it is possible to obtain a cross-sectional shape having a very clear shape line. Therefore, it is possible to observe and measure the internal shape of the elastic body easily and with high accuracy by using the cross-sectional image obtained by the computed tomography.

In the method for observing the internal shape of a hollow elastic body according to the present invention, the hollow elastic body can be elastically deformed under an external load or under an external load. The hollow internal shape can be observed.

Further, the method for testing the deformation of a hollow elastic body according to the present invention makes it possible to easily measure the internal shape of the hollow body under the deformed state of the elastic body even under a load condition where observation from the outside is extremely difficult. By using the measurement results for design and the like, it is possible to easily realize an improvement in the performance of the elastic body based on a more suitable design.

In particular, in the method for testing the deformation of a hollow elastic body according to the present invention, for example, another member is mounted on a hollow portion of the elastic body, and the other member is mounted on the elastic body. It is also possible to use a cross-sectional image by computer tomography. This makes it possible to easily and clearly measure the influence and interference with other members when the elastic body is deformed, which was extremely difficult in the past, and the measurement results are advantageously used for design and the like. It can be done.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described.
This will be described in detail with reference to the drawings.

First, FIG. 1 shows a schematic configuration of a computer tomography apparatus used in the method of the present invention.
The computed tomography apparatus 10 is a kind of tomography apparatus called an X-ray CT apparatus in the field of medical equipment, and is projection data from a plurality of directions obtained by using an X-ray transmission characteristic inherent to a substance. Is digitized and processed by a computer to reconstruct a cross-sectional image.

More specifically, the computed tomography apparatus 10 includes an annular rotating base 12, and the rotating base 12 causes an X-ray tube 14 that generates X-rays.
And an X-ray detector 16 for detecting X-rays projected from the X-ray tube 14 are supported at positions facing each other. Then, as shown in FIG.
8 is positioned between the opposing surfaces of the X-ray tube 14 and the X-ray detector 16 in the rotating gantry 12, and when a measurement start signal is input by an operation device 17 such as an external operation panel, CP
According to U20, X-rays are projected from the X-ray tube 12 toward the elastic body 18 by the X-ray generation unit 22 including a high-pressure generation unit and an X-ray control unit according to a preset program, and the rotating gantry 12 is It is rotated. As a result, the X-rays projected onto the elastic body 18 from a plurality of directions and transmitted through the elastic body 18 are reflected by the X-ray detector 1.
6, the signal is detected as an X-ray intensity signal, and the detected signal is collected and converted into a digital signal.
Is forwarded to Then, the CPU 20 performs the calculation according to a preset algorithm, for example, according to a known algorithm such as a back projection method, a successive approximation method, a Fourier transform method, a filtered back projection method, and a convolution method.
An image is reconstructed from the obtained X-ray transmission data in a plurality of directions, and this image data is stored in an external storage device 24 using a magnetic storage medium or the like, and a CR
A cross-sectional image of the elastic body 18 is visibly displayed by an external display device 26 such as T.

Although the computer tomography apparatus 10 used in the medical field can be used as it is, a more compact apparatus can be used in consideration of the size of the object 18 to be observed. Can be used, and instead of employing the rotating gantry 12, the observed object 18 may be rotated around one axis. Furthermore,
Considering the shape of the observed body 18 and the like, if the shape is simple,
The apparatus configuration can be further simplified by reducing the X-ray projection direction, simplifying an algorithm for image reconstruction, and the like. Alternatively, since the observation target 18 is not a living body and the X-ray exposure dose does not need to be particularly considered, it is also possible to set the intensity of the projected X-ray so that a clear cross-sectional image is obtained. .

Incidentally, the X-ray CT having the structure as described above is used.
An embodiment in the case where the elastic deformation of a bump stopper for an automobile is measured using the apparatus will be described. As is well known, the bump stopper generally has a substantially hollow cylindrical shape, is externally mounted on the piston rod of the shock absorber, and stably secures the intended shock absorption characteristics and durability. For this purpose, it is important to prevent buckling deformation at the time of elastic deformation due to load input and to prevent interference of the inner peripheral surface of the hollow hole with the piston rod. Therefore, as shown in FIG. 2, a bump stopper 30 having an insertion hole 28 as a hollow portion penetrating in the axial direction is replaced with a rod having the same outer dimensions as a piston rod of a shock absorber to be actually mounted. 32, the first pressing plate 34 is screwed and fixed to one end in the axial direction of the rod 32,
By externally inserting the second pressing plate 36 from the other axial direction of the rod 32 and displacing the second pressing plate 36 toward the first pressing plate 34 by a screw feed mechanism (not shown), The maximum load applied to the bump stopper 30 under the actual mounting state is input as a static load in the axial direction between the mutually opposing surfaces 38, 40 of the first and second pressing plates 34, 36 as a static load. It was kept in an elastically deformed state.
Then, the bump stopper 30 in the elastically deformed state.
Was set in an X-ray CT apparatus as an object to be observed, and a cross-sectional image was obtained. The material of the bump stopper 30 used in the present embodiment is polyurethane foam, and the material of the rod 32 and the first and second pressing plates 34 and 36 is an acrylic resin. FIG. 3 shows the obtained cross-sectional image.

As is clear from the cross-sectional images obtained as a result of the embodiment shown in FIG. 3, according to the method of the present invention, a very clear cross-sectional image can be obtained. The shape of the inner peripheral surface of the hollow hole 28, which has been extremely difficult to detect even using the X-ray fluoroscopic image, can be observed very clearly to the same extent as the outer peripheral surface shape. Therefore,
By using the obtained cross-sectional image, it is possible to easily examine the presence or absence of buckling deformation in the bump stopper 30, the presence or absence of buffering on the piston rod, the possibility of buffering, and the like. It is possible to easily realize the discovery and prevention of defects, or the optimal design by feedback to the design. In addition, since the obtained cross-sectional image can be appropriately set to a reduced scale with the real thing by computer processing, the
Dimension measurement, a test for measuring the amount of deformation, and the like can also be advantageously performed.

The embodiments and specific examples of the present invention have been described in detail above. However, these are merely examples, and the present invention is not limited to the above-described specific description.
It is not to be construed as limiting.

For example, in the above-described embodiment, a specific example in which an X-ray CT apparatus is employed as a computer tomography method has been described. And can be adopted as appropriate.

Further, the present invention is not limited to the illustrated bump stopper, but may be employed for observing the internal shape of various hollow structural elastic bodies or performing a deformation test.
For observing and measuring the deformation state of the fluid chamber and air chamber during deformation of a hollow elastic body with a fluid chamber filled with an incompressible fluid or an air chamber filled with air, etc. However, the present invention can be suitably adopted.

Further, the present invention is not limited to a state in which another member such as a rod is attached to the hollow portion of the elastic body as shown in the example. The present invention can be advantageously employed also in observation of a deformed elastic body, deformation test, and the like.

[0025]

As is apparent from the above description, according to the present invention, when observing the hollow inner surface shape of the elastic body,
It has been clarified that computed tomography utilizing the physical properties of the elastic body can be employed very advantageously. In particular, in the method for observing the internal shape of a hollow elastic body according to the present invention, it is invisible from the outside. It is possible to observe the inner peripheral surface shape of the hollow structure, which was extremely difficult to recognize even using the X-ray fluoroscopic image, with a very clear shape line, to the same extent as the outer peripheral surface shape. It is.

In the method for testing the deformation of a hollow elastic body according to the present invention, the inner peripheral surface shape of the hollow structure in the elastically deformed state can be recognized with the same clear shape line as before the elastic deformation. Therefore, it is possible to easily find and prevent a defect at the time of elastic deformation, or to optimally design by feedback to the design.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of a computed tomography apparatus that can be used in the method of the present invention.

FIG. 2 shows an X-ray CT apparatus having the structure shown in FIG.
It is an explanatory view for explaining the observation method according to the method of the present invention.

FIG. 3 is a drawing substitute X-ray photograph of the bump stopper shown in FIG. 2, showing a specific example of a cross-sectional image obtained by using the X-ray CT apparatus having the structure shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Computed tomography apparatus 28 Insertion hole 30 Bump stopper 32 Rod

Claims (3)

[Claims] When observing the internal shape of a non-metal elastic body having a hollow structure, a cross-sectional image of the elastic body is obtained by using a computed tomography method utilizing abiotic physical characteristics. A method for observing the internal shape of a hollow elastic body, comprising observing the internal shape of the elastic body. 2. A method for testing deformation of a non-metallic elastic body having a hollow structure, wherein the method is performed by a computer tomography method using an abiotic physical property in a state where an external load is applied to the elastic body. A method for testing the deformation of a hollow elastic body, comprising measuring a deformed shape of the elastic body using a cross-sectional image of the elastic body. 3. A cross-sectional image obtained by mounting the other member on the hollow portion of the elastic body, the cross-sectional image obtained by the computed tomography method obtained in a state where the other member is mounted on the elastic body. 3. The deformation test method for a hollow elastic body according to 2.