JPH0451994Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a surface plate equipped with a reference plane for use in various operations such as centering, scribing, measuring, and aligning workpieces, and is particularly suitable for use with high-frequency waves. This article relates to a concrete surface plate that is most suitable for use in inspection equipment that performs measurements.

[Conventional technology]

Conventionally, there are two types of this type of surface plate: cast iron and stone, and depending on the flatness of the surface used, they are grade 0, grade 1, and grade 2.
The revised JIS standards refer to these as precision surface plates.

The material for the cast iron surface plate is JIS G.
FC20 of 5501 (gray cast iron) or equivalent or higher, the structure is uniform, there are no harmful defects such as cavities, pinholes, cracks, etc., and necessary heat treatment or natural drying is performed to remove internal stress. There are provisions such as what must be done.

In addition, the material for the stone surface plate is stipulated that it must be made of grazestone or a stone of a higher quality, have a uniform structure, and be free from defects such as harmful striae and cracks. A cast iron or stone surface plate that satisfies the following conditions is used.

[Problem that the invention attempts to solve]

In general, the characteristics required for this type of surface plate include rigidity (flexural strength), wear resistance, precision (flatness, perpendicularity, parallelism), as well as acid resistance and thermal effects (heat resistance). For example, it is difficult to undergo expansion (e.g. expansion).

However, although conventional cast iron surface plates have excellent mechanical properties, they are inferior in wear resistance, and their high thermal conductivity makes them susceptible to thermal deformation, as well as being expensive. There is a problem.

In contrast, stone surface plates are more than twice as hard as cast iron, have much higher wear resistance, are stable without being affected by temperature, and are less prone to thermal deformation. On the other hand, it has lower mechanical strength (rigidity) than cast iron, so it needs to be thicker to compensate for the rigidity, it is difficult to achieve precision, and because it is a natural stone, it is expensive and difficult to obtain. There are some drawbacks that I mentioned.

Additionally, when using a surface plate as a mounting stand for inspection equipment that performs measurements related to electromagnetic waves, it is desirable to have an electromagnetic shielding function. It is difficult to provide this function, and there are various problems such as its use as a surface plate is limited. Furthermore, JP-A-61-197173 discloses a surface plate in which a wire mesh is buried, but this is buried to reinforce the surface plate and provides an electromagnetic shielding function. It is not an invention made in this way.

[Means for solving problems]

The present invention was made in order to solve the conventional problems as described above, and it is a concrete surface plate that has the above-mentioned characteristics required for a surface plate and also has an electromagnetic shielding function. The purpose is to provide a metal bush with an upper end exposed above the base and a lower end connected to a conductor for electromagnetic shielding, which is embedded in a concrete base containing silica fume. The concrete surface plate is characterized in that at least the upper layer of the base is coated with resin by impregnation.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the embodiments shown in FIGS. 1 to 5. In addition, FIG. 1 is a vertical cross-sectional view of a concrete surface plate according to the present invention, FIG. 2 is a plan view of a conductor buried in the identification board, and FIG. 3 is a cross-sectional explanatory diagram showing a method for manufacturing the identification board. Figure 4 is a block diagram showing the process of resin impregnation of the identification board.
FIG. 5 is an explanatory diagram showing the state of use.

In the figure, 1 is a concrete surface plate according to the present invention, which is made of concrete mixed with silica hume.

Table 1 shows an example of its formulation. It is made by mixing fine particles of silica hume, water, aggregate, admixtures, etc. with cement. In the case of formulation example 1, the compressive strength of base A is approximately 1200 kg/cm ² , or Mixture Example 2, the compressive strength is approximately 1000Kg/ ^cm2 , and the compressive strength of the base made of ordinary concrete is approximately 659Kg/cm2.
significantly increased compared to ^cm2 . This is because the cement is densely and uniformly filled with fine particles of silica fume, resulting in high strength and high wear resistance. In addition, as shown in the comparison of physical properties in Table 2, although the coefficient of linear expansion of this base A is somewhat large, its thermal conductivity is extremely low compared to conventional cast iron, so it is difficult to cause thermal deformation. It has certain characteristics.

2 is a resin impregnated into the base A, for example, methyl methacrylate monomer (MMA monomer).
using benzoyl peroxide as a catalyst.
Dicyclohexyl phthalate powder containing 50% was used, and γ-methacryloxypropyltrimethoxysilane was used as a coupling agent.

By impregnating the concrete base A mixed with silica fume with the resin, the voids in the concrete in the surface layer of the base A were filled with the resin. As a result, the average value of the compressive strength in the three experimental examples was approximately 2491 Kg/ ^cm2 , which is approximately twice the compressive strength of the base before resin impregnation.Moreover, the surface uniformity was improved, and the cement and bone The adhesion force with materials etc. also increased.

3 is a conductor for electromagnetic shielding in the form of a wire mesh, which is formed by molding a metal plate with good conductivity such as copper, and is stretched horizontally over the entire upper part of the base A by the method described later. It is buried within the material.

4 is a metal bush for mounting the equipment, which has a female thread cut on its inner periphery, and is embedded in the required location of the base A. Similar to the electromagnetic shielding conductor 3, this metal bushing 4 is buried in concrete material at the time of molding the base A, and its lower end 4a
is in contact with the electromagnetic shielding conductor 3, and may be brazed or welded to ensure the contact.

Reference numeral 5 denotes a base plate, which is fixed on the surface plate 1 by screwing bolts 6 into metal bushes 4, and on which the inspection device B is placed. However, this base plate 5 is not necessary when the reference plane 1a of the surface plate 1 is formed with high precision, and in this case, the inspection device etc. B is placed directly on the surface plate 1.

Reference numeral 7 denotes a grounding wire to the outside, which is fixed to the metal bushing 4 with a bolt 8. The metal bushing 4 in contact with the electromagnetic shielding conductor 3 achieves grounding wiring for each of the base boards 5.

Next, an example of a method for manufacturing the surface plate 1 according to the present invention will be explained based on FIG. 3.

First, a formwork 9 of a size that can accommodate the surface plate 1 is made using a suitable material, an array plate 10 is placed on the bottom plate 9a of the formwork 9, and the metal bushes 4 are placed on the array plate 10 at its open end. 4b facing downward. It goes without saying that the metal bushing 4 is arranged in a position that corresponds to the mounting hole of the base board 5.

Then, as shown in FIG. 2, a wire mesh 3 used as a conductor for electromagnetic shielding is placed horizontally on top of the metal bushing 4 in contact with it, and the wire mesh 3 and the metal bushing 4 are placed in contact with each other as needed. contact part 4a with
Fix by brazing or welding.

Next, concrete material containing silica fume is poured into the formwork 9 to a predetermined height, and the concrete material passes through the meshes 3a of the wire mesh 3 and is filled up to the array plate 10.

Then, if necessary, press a push plate 11 from above to wait for the concrete material to ripen, and after a certain period of time, the concrete material hardens, and the wire mesh 3 buried inside and the concrete material are integrated into a surface plate. A base A, which is a prototype of No. 1, is formed. That is,
The wire mesh 3 is used as a base, and the upper and lower concrete layers are connected through the mesh 3a of the wire mesh 3, and because the adhesion between the wire mesh 3 and the concrete material is good, the entire structure is integrated. Become.

After curing, the substrate A is taken out from the mold 9 and impregnated with the resin 2 by the means described below. That is, as shown in FIG. 4, first, in a steam curing step 10, the material is cured at a temperature of about 80° C. and a pressure of about 10 kg/cm ² for about 4 hours. Then heating drying process
In step 11, the product is dried by maintaining it at a temperature of 150° C. for 3 to 7 days, and further in degassing step 12, it is degassed using a vacuum pump at a pressure of about 10 mmHg or less for about 1 hour.

Next, in an impregnation step 13, the substrate A is immersed in a liquid resin as an impregnating material under atmospheric pressure to impregnate the substrate A with the resin for about 24 hours, and then in a heating polymerization step 14, heated at a temperature of about 90°C. The polymerization reaction is completed by holding it in water for about 3 hours, and then the upper surface of the substrate A is finished in a finishing step 15. That is, in FIG. 3, the surface that comes into contact with the array plate 10 is the upper surface of the surface plate 1, so this surface 1a and the opening end surface 4b of the metal bushing 4 are co-polished to form a smooth reference plane, and the finished product is completed. Assume that surface plate 1 is a product.

Next, the usage state of the surface plate according to the present invention will be explained based on FIG. The inspection device B is placed on the base board 5 by screwing it into the base plate 5, positioning it precisely, and fixing it. Then, the grounding wire 7 is similarly fixed to the metal bushing 4 with bolts 8.

Since the surface plate 1 has an electromagnetic shielding function, it will not have any adverse effects even when used for measurements related to electromagnetic waves.

[Effect of idea]

As mentioned above, the concrete surface plate according to the present invention is integrally formed by burying a metal bushing whose upper end is exposed on the upper surface of the base and whose lower end is connected to a conductor for electromagnetic shielding in a concrete base containing silica fume. Then, since the resin is disposed in at least the upper layer of the base, it is possible to obtain a surface plate with high strength and high surface precision, and the thermal conductivity is low. Heat deformation is less likely to occur, and deterioration over time is also significantly reduced.

In addition, no dust is generated due to wear, there is almost no water absorption or permeability, and there is no drying shrinkage, as the surface plate is integrally formed with a conductor buried inside it. It has an electromagnetic shielding function and can be used, for example, as a surface plate for inspection equipment that performs high-frequency measurements, and has various effects that expand the range of uses for surface plates.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a concrete surface plate according to the present invention, Fig. 2 is a plan view of a shielding conductor buried in the identification board, Fig. 3 is a cross-sectional explanatory diagram showing the method for manufacturing the identification board, FIG. 4 is a block diagram showing the process of impregnating the identification board with resin, and FIG. 5 is an explanatory diagram showing the state of use. 1...Concrete surface plate, 1a...Reference plane, A...Base, 2...Resin, 3...Electromagnetic shielding conductor, 4...Metal bushing, 4a...Lower end, 4b...Open end ( top).

【table】

【table】

Claims (1)

[Scope of utility model registration request] A metal bush whose upper end is exposed on the upper surface of the base and whose lower end is connected to a conductor for electromagnetic shielding is buried in a concrete base containing silica fume, and at least the upper layer of the base is impregnated. A concrete surface plate characterized by resin.