JP3639735B2 - Gauge block and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gauge block used as a reference device when measuring a length dimension precisely.
[0002]
[Prior art]
Conventionally, a gauge block has been used as a reference device for measuring a length dimension precisely. Since the gauge block is a reference device for precise dimension measurement, it needs to be excellent in wear resistance and corrosion resistance. This is because if wear or corrosion occurs easily, it cannot be used as a reference device, and ringing that is used in close contact with other gauge blocks cannot be performed. For this reason, steel, ceramics, low thermal expansion glass, and the like are conventionally used as a material for the gauge block.
[0003]
[Problems to be solved by the invention]
Gauge blocks made of metal such as steel are prone to corrosion and cannot be said to have sufficient corrosion resistance. For this reason, it is necessary to store a steel gauge block in a completely corrosion-resistant environment, and there is a problem that handling is extremely complicated, as handling is always performed while wearing corrosion-resistant gloves. In order to solve such problems, in recent years, the wear resistance and corrosion resistance of metal gauge blocks have been improved by material selection and heat treatment, but material selection, heat treatment, etc. Since it takes a long time, the production cost increases.
[0004]
In particular, steel gauge blocks need to be hardened and hardened by heat treatment (quenching), but there is a problem that aging changes due to structural changes caused by quenching. ing. In addition, the quenching increases the cost.
[0005]
On the other hand, in recent years, techniques have been used to reduce aging dimensional changes by special heat treatment such as sub-zero and temper treatment, artificial aging treatment, natural aging, etc., but sufficient effects are not necessarily obtained. Currently. Moreover, performing special processing causes a further increase in cost.
[0006]
As a technique for forming a hard thin film on the reference surface of the gauge block, for example, Japanese Patent Publication No. 8-20201 is available. The main purpose of this is to prevent dust on the reference surface, and a hard thin film having an uneven surface is formed. However, when such irregularities are formed on the reference surface, there is a problem that a so-called ringing in which a plurality of gauge blocks are used with their reference surfaces in close contact with each other becomes impossible. In order to perform ringing, the reference surface of the gauge block needs to be a surface having no unevenness and high smoothness.
[0007]
An object of the present invention is to provide a gauge block that is excellent in wear resistance and corrosion resistance, does not change over time, and can be manufactured at low cost, and a method for manufacturing the same.
[0008]
[Means for Solving the Problems]
One aspect of the gauge block according to the present invention is characterized in that the surface of the gauge block main body is coated with a TiN film, and the gauge block main body is a steel raw material that has not been hardened. In another aspect of the gauge block according to the present invention, the surface of the gauge block main body is coated with a TiN film, and the gauge block main body is a steel raw material obtained by quenching only the surface portion of the surface serving as a reference surface. It is characterized by being.
[0009]
The method of manufacturing a gauge block according to the present invention includes a step of processing a gauge block body with a steel raw material that has not been hardened, a step of forming a TiN film on the surface of the gauge block body by physical vapor deposition, And a step of finishing the surface of the gauge block on which the TiN film is formed and exposing the reference surface in a state where the TiN film is left.
[0010]
According to the present invention, the performance and reliability of the gauge block can be improved by the coating of the TiN film having excellent wear resistance and corrosion resistance.
In particular, in this invention, when a steel raw material not subjected to hardening treatment such as quenching is used as the gauge block main body, there is no aging change due to structural change as in the case of quenching, and stable for a long period of time. A usable gauge block is obtained. Further, there is no need for quenching, special heat treatment (sub-zero, temper treatment), artificial aging treatment, natural aging, etc., and the production cost and production time can be reduced.
[0011]
Other gauge block bodies to which the TiN coating is applied include ceramics and low thermal expansion glass. As the ceramic, a ceramic mainly composed of zirconia (zirconium oxide: ZrO ₂ ) is preferable. Further, as the low thermal expansion glass, solid solution type glass, for example, 60 to 70% by weight of silicon dioxide SiO _{2 as} a main component, 15 to 25% by weight of aluminum oxide Al ₂ O ₃ , and 1.5 to 5% by weight. There is a glass containing lithium oxide Li ₂ O.
[0012]
The coating of the TiN film is preferably performed by physical vapor deposition (PVD method), in particular, a multi-arc ion plating method. In this case, the gauge block is preliminarily processed so that the dimension between the reference planes is slightly smaller than a desired value in anticipation of the thickness of the TiN film, and the TiN film is coated, and then finish polishing is performed to about 1 μm. A reference surface having a desired dimension is formed with the TiN film remaining. As a result, unevenness in film thickness and deformation of the gauge block body are corrected.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a gauge block according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a manufacturing process of a gauge block. FIG. 1A shows a processed cross section of the gauge block body 1. In this embodiment, the gauge block body 1 is a raw steel material that has not been hardened, and the formation of the TiN film is expected between the surface A0 to be the reference surface with respect to the desired dimension D. , Processed to have a slightly smaller dimension D-d1.
[0014]
Next, a TiN film 2 is formed on the surface of the gauge block body 1 as shown in FIG. In the case of this embodiment, ion plating was used to form the TiN film 2. As shown in FIG. 2, the ion plating apparatus is a multi-arc system having a plurality of ion sources 21. The substrate holder is a self-revolving holder having a main holder 22 that is rotationally driven and a sub-holder 23 that is rotationally driven thereon, and the gauge block body 1 is placed on the sub-holder 23 with the reference plane vertical. A TiN film is formed. For example, TiCl ₄ gas is used as a raw material gas, which is converted into plasma by the ion source 21 and nitrogen gas N ₂ and hydrogen gas H ₂ are supplied to perform TiN synthesis.
[0015]
The conditions for forming the TiN film are a temperature of 150 to 400 ° C. and a time of 2 to 3 hours. Thereby, about 3-4 micrometers TiN film | membrane 2 is formed in both surfaces which should become the reference plane of the gauge block main body 1. FIG. At this time, the thickness of the gauge block body 1 is slightly thicker than the desired thickness D, and becomes D + d2.
FIG. 1B shows a state in which the TiN film is formed not only on the reference surface A but also on other surfaces. Coating the entire surface with a TiN film is effective in that the effect of rust prevention is obtained and that special masking is unnecessary.
[0016]
Subsequently, both surfaces to be reference surfaces on which the TiN film 2 is formed are finish-polished, and as shown in FIG. 1C, the desired dimension D, parallelism, and smoothness are left with the TiN film 2 left. A reference plane A1 having a degree is obtained. At this time, the remaining film thickness of the TiN film 2 is about 1 μm.
[0017]
In this embodiment, since the gauge block body 1 is not quenched, the hardness is approximately Hv = 230, but the coating of the TiN film 2 provides a high hardness gauge block of Hv = 2300. For reference, the hardness of a conventional steel gauge block is Hv = 800, the hardness of uncoated zirconia ceramics is Hv = 1350, and the low thermal expansion glass without coating is Hv = 700.
[0018]
As described above, according to this embodiment, a gauge block having high hardness, excellent wear resistance, and excellent corrosion resistance can be obtained. Since the steel block is used for the gauge block main body, the structural change caused by quenching as in the past and the secular change associated therewith are suppressed, and a highly reliable long-term gauge block can be obtained. Also, no special heat treatment such as sub-zero or tempering is required, and the cost of the gauge block can be reduced.
[0019]
In the above embodiment, it is effective to partially quench only the surface A0 to be the reference surface of the gauge block body 1 at the stage of FIG. More specifically, this partial quenching is, specifically, induction hardening (a method in which induction heating is applied to the work piece and partial heating is performed using the high frequency heating device coil as a primary coil and the work piece as a secondary coil). It is performed by a method such as carburizing and quenching or nitriding.
When such partial quenching is performed, the effect of preventing scratches and the like is obtained as compared with the case where the whole is a raw steel material, and even when the TiN film becomes extremely thin by finish polishing, It becomes possible to guarantee a certain level of wear resistance and corrosion resistance. Also, if the gauge block is not fully quenched, the effects of steel structural changes and aging changes associated therewith can be suppressed.
[0020]
Further, in the examples, the gauge block in which TiN coating is applied to the steel raw material has been described. However, the present invention is not limited to this, and the TiN coating is applied to the gauge block using, for example, ceramics or low thermal expansion glass. You may give it.
[0021]
【The invention's effect】
As described above, according to the present invention, since the TiN coating is applied, it is possible to provide a gauge block that is excellent in wear resistance and corrosion resistance, does not change over time, and can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 shows a manufacturing process of a gauge block according to an embodiment of the present invention.
FIG. 2 shows an ion plating apparatus for forming a TiN film according to the same embodiment.
[Explanation of symbols]
1 ... Gauge block body, 2 ... TiN film.

Claims (3)

A gauge block, wherein a surface of the gauge block main body is coated with a TiN film, and the gauge block main body is a raw steel material that has not been hardened . A gauge block characterized in that the surface of the gauge block body is coated with a TiN film, and the gauge block body is a raw steel material obtained by quenching only the surface portion of the surface to be a reference surface. Processing the gauge block body with steel raw material that has not been hardened;
Forming a TiN film on the surface of the gauge block body by physical vapor deposition;
And finishing the surface of the gauge block main body on which the TiN film is formed so as to leave a reference surface in a state where the TiN film remains.

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