JPS58186010A - Apparatus for measuring thickness of coated film of synthetic resin - Google Patents
Apparatus for measuring thickness of coated film of synthetic resinInfo
- Publication number
- JPS58186010A JPS58186010A JP6816482A JP6816482A JPS58186010A JP S58186010 A JPS58186010 A JP S58186010A JP 6816482 A JP6816482 A JP 6816482A JP 6816482 A JP6816482 A JP 6816482A JP S58186010 A JPS58186010 A JP S58186010A
- Authority
- JP
- Japan
- Prior art keywords
- film thickness
- temp
- measuring
- ultrasonic
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
- G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
- G01B17/025—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness for measuring thickness of coating
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は合成樹脂で被覆した製品の被覆厚みを測定する
装置、特にポリエチレン被覆鋼管等の被覆膜厚を超音波
を用いてオンラインで測定するのに適した装置に関する
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the coating thickness of a product coated with a synthetic resin, and particularly to a device suitable for online measuring the coating thickness of polyethylene-coated steel pipes, etc. using ultrasonic waves. .
ポリエチレン、塩化ビニール等合成樹脂膜の厚みを測定
するには、従来から電磁膜厚計や超音波厚さ計が使われ
ている。電磁膜厚計は強磁性体上に接した非電導膜に探
触子を接触させることにより、その電磁作用を利用して
膜厚を測定する。被Ｉ Ｐ
Ｐ
測定物であるポリエチレン等の合成樹脂は常温状態では
ある程度の硬さを有し、探触子等の接触によってもさほ
ど傷つくことはない。しかしながら成型途中の中、高温
状態においては、熱可塑性のこれらの樹脂は非常に柔く
傷つき易い。したがって成型途中の膜厚測定には探触子
を被覆膜に接触させて測定する電磁膜厚計は適切でない
。特に被覆すべき成品を移動させながら被覆膜を成型し
、同時に被覆成品の膜厚を測定することは被覆膜を探触
子がこすることになり、成品表面を傷つけ、精度もよく
ない。Electromagnetic film thickness gauges and ultrasonic thickness gauges have traditionally been used to measure the thickness of synthetic resin films such as polyethylene and vinyl chloride. An electromagnetic film thickness meter measures film thickness by bringing a probe into contact with a non-conductive film on a ferromagnetic material and utilizing its electromagnetic effect. IP addressee
P The synthetic resin such as polyethylene that is the object to be measured has a certain degree of hardness at room temperature, and will not be seriously damaged by contact with a probe or the like. However, at high temperatures during molding, these thermoplastic resins are very soft and easily damaged. Therefore, an electromagnetic film thickness meter, which measures the film thickness by bringing a probe into contact with the coating film, is not suitable for measuring the film thickness during molding. In particular, molding a coating film while moving the product to be coated and measuring the film thickness of the coated product at the same time means that the probe will rub against the coating film, damaging the product surface and improving accuracy. .
これに対し超音波厚さ計は、被覆体に水、油等の接触媒
質を介して探触子を接触させるか、あるいは水ジエツト
水流等による水柱を介し非接触で探触子をセットし、該
探触子から超音波パルスを被覆体の合成樹脂内に伝播さ
せ、その超音波進行時間を測定し、これに既知の超音波
音速を乗じて厚さを測定するので、成品表面を傷つける
ことはない。しかし、ポリエチレン等合成樹脂を伝播す
る超音波の音速は温度依存性が大きく、わずかの ２−
温度変化でもかなりの音速の変化を示す。このため超音
波を使っての膜厚測定は、中、高温状態においては被覆
膜の温度変化に起因して膜厚測定値が太きくばらつき、
測定積置が非常に悪い。On the other hand, with an ultrasonic thickness gauge, the probe is placed in contact with the coating via a couplant such as water or oil, or the probe is set in a non-contact manner via a water column such as a water jet. Ultrasonic pulses are propagated from the probe into the synthetic resin of the coating, the ultrasonic travel time is measured, and this is multiplied by the known ultrasonic sound speed to measure the thickness, so there is no chance of damaging the surface of the product. There isn't. However, the sound speed of ultrasonic waves propagating through synthetic resins such as polyethylene is highly temperature dependent, and even a slight change in temperature causes a considerable change in the sound speed. For this reason, when measuring film thickness using ultrasonic waves, in medium to high temperature conditions, the film thickness measurement value varies widely due to temperature changes in the coating film.
The measurement stacking is very poor.
本発明は上述した問題を解決し、成型途中の合成樹脂被
覆膜の膜厚を非接触でかつ温度変化に影響されることな
く高精度で測定することのできる合成樹脂被覆膜厚測定
装置を提供することを目的とする。The present invention solves the above-mentioned problems and is capable of measuring the thickness of a synthetic resin coating in a non-contact manner and with high precision without being affected by temperature changes. The purpose is to provide
本発明は、非接触水流ジェット式超音波パルス式厚さ計
により被覆膜厚を測定するとともに、膜厚測定部におけ
る合成樹脂被覆膜の表面温度を非接触温度計で測定し、
予め温度変化による音速変化量を求めておき、これを基
にコンピュータにより温度変化による膜厚補正量を計算
し、前記超音波パルス式環さ計で測定した膜厚を補正す
るようにしたものである。The present invention measures the coating film thickness with a non-contact water jet type ultrasonic pulse type thickness meter, and also measures the surface temperature of the synthetic resin coating film in the film thickness measurement section with a non-contact thermometer,
The amount of sound velocity change due to temperature change is determined in advance, and based on this, a computer calculates the amount of film thickness correction due to temperature change, and the film thickness measured by the ultrasonic pulse type cylindrical gage is corrected. be.
以下、本発明を図面を診照しながら、実施例について説
明する。Hereinafter, embodiments of the present invention will be described with reference to the drawings.
第１図は高密度ポリエチレン樹脂の被覆体内を超音波が
伝播する場合の、温度変化に対する音速の相対的変化量
を示した図である。一般に合成樹脂の温度が上昇するに
つれて音速は遅くなる。図示の例では、例えば測定点の
温度が３０℃程異なると音速は１０％はど変化するので
、膜厚測定誤差もそのままでは１０％生ずることになる
。第１図に示す如く、高密度ポリエチレン樹脂の被覆体
内を超音波が伝播する場合の、被覆体の温度ｔと音速相
対変化量ｙについては、一般的に、Ｖ−−０，００３１
４ｔ＋α −・・・・・（１）ただしα；定数
の関係がある。しかしこの（１）式は被覆体を恒温槽に
て充分均一な温度状態にして測定したものであり、これ
に比べて実際の操業にあっては、約１３０℃に予熱され
た鋼管に約２００℃のポリエチレンを被覆し、次いでこ
のポリエチレン被覆の表面温度が８０℃前後になるよう
に水冷した後、被覆膜厚を測定するのであ壷））、被覆
後膜厚測定までの時間は４分から１０分とまちまちであ
るので、当然被覆体の温度は表面と鋼管に接する面とで
は温度差が生じており、被覆体の厚さ方向に温度勾配が
生じていると考えられる。しかも、鋼管の先後端と中央
部では鋼管自体の温度にも差が生じており、この温度勾
配も一定ではないと考えられる。従って被覆のおおよそ
の厚さ、測定部位等、更には鋼管径、肉厚、大気温度等
に応じて実験を繰り返し、適宜最適な補正式を用意して
おく必要がある。FIG. 1 is a diagram showing the relative amount of change in sound speed with respect to temperature change when ultrasonic waves propagate inside a coating made of high-density polyethylene resin. Generally, as the temperature of the synthetic resin increases, the speed of sound decreases. In the illustrated example, if the temperature at the measurement point differs by about 30° C., the sound velocity changes by 10%, so if left unchanged, the film thickness measurement error will also occur by 10%. As shown in Fig. 1, when an ultrasonic wave propagates inside a high-density polyethylene resin coating, the temperature t of the coating and the relative change in sound velocity y are generally V-0,0031.
4t+α − (1) However, α: There is a constant relationship. However, this equation (1) was measured with the coating in a sufficiently uniform temperature state in a constant temperature bath, and compared to this, in actual operation, a steel pipe preheated to about 130°C has a temperature of about 200°C. The coating film thickness is measured after coating with polyethylene at ℃ and then cooling with water so that the surface temperature of the polyethylene coating becomes around 80℃. Since the heating time varies from 10 minutes to 10 minutes, it is natural that there is a temperature difference between the surface of the coating and the surface in contact with the steel pipe, and it is thought that a temperature gradient occurs in the thickness direction of the coating. Furthermore, there is a difference in the temperature of the steel pipe itself between the front and rear ends and the center, and it is thought that this temperature gradient is also not constant. Therefore, it is necessary to prepare an appropriate correction formula by repeating experiments depending on the approximate thickness of the coating, the measurement site, etc., as well as the steel pipe diameter, wall thickness, atmospheric temperature, etc.
本発明では超音波パルスを合成樹脂被覆膜に向けて発し
、その超音波が被覆膜と成品例えば鋼管との接触面で反
射されて戻ってくるエコーを受け、その間の時間差に、
該被覆膜材質に応じた成る温度における既知音速を乗じ
て膜厚を算出し、さらにこの膜厚を温度と音速との関係
を用いて補正する。In the present invention, ultrasonic pulses are emitted toward the synthetic resin coating, and the ultrasonic waves are reflected at the contact surface between the coating and the product, such as a steel pipe, and receive echoes that return, and due to the time difference between them,
The film thickness is calculated by multiplying by the known speed of sound at a temperature corresponding to the material of the coating film, and the film thickness is further corrected using the relationship between temperature and sound speed.
第２図は本発明の実施例に係る膜厚測定装置の全体構成
を系統的に示したブロック図である。被測定物であるポ
リエチレン被覆鋼管ｌはスキューローラ２ 、２’によ
ってスパイラル状に送られる。FIG. 2 is a block diagram systematically showing the overall configuration of a film thickness measuring device according to an embodiment of the present invention. A polyethylene-coated steel pipe l, which is an object to be measured, is sent in a spiral shape by skew rollers 2 and 2'.
図示されていないが、この間にポリエチレン樹脂が公知
の方法で成型されて鋼管成品の外周に被覆される。鋼管
の搬送ライン上で被覆の終った鋼管ｌの下方に超音波探
触子３および水噴出ノズル５が配置され、水供給管６か
らノズル５を介して鋼管１の外周に水が柱状に噴射され
る。７はこの場合の水柱であり、超音波探触子３からの
超音波は水柱７内を伝播する。超音波探触子３はパルス
状の超音波ビームの発振および発振した超音波ビームが
鋼管ｌの被覆膜接触面で反射して戻ってくるエコーの受
信を兼ねている。超音波の発振から受信までの時間差は
超音波膜厚測定装置４で測定され、既知あるいは標準音
速を乗じて膜厚が測定される。Although not shown, during this time, polyethylene resin is molded by a known method to coat the outer periphery of the steel pipe product. An ultrasonic probe 3 and a water jet nozzle 5 are arranged below the coated steel pipe l on the steel pipe conveyance line, and water is jetted in a columnar manner from the water supply pipe 6 to the outer periphery of the steel pipe 1 via the nozzle 5. be done. 7 is a water column in this case, and the ultrasonic waves from the ultrasonic probe 3 propagate within the water column 7. The ultrasonic probe 3 serves both to oscillate a pulsed ultrasonic beam and to receive echoes returned from the oscillated ultrasonic beam reflected by the contact surface of the coating film of the steel pipe 1. The time difference from oscillation to reception of the ultrasonic wave is measured by the ultrasonic film thickness measuring device 4, and the film thickness is measured by multiplying by a known or standard sound speed.
鋼管ｌの測定点の上方位置に、非接触で、温度センサ８
が設置され、該温度センサおよび温度測定装置９によっ
て鋼管１における被覆膜の温度が測定される。ポリエチ
レンの被覆を完了した直後は被覆鋼管表面温度は２００
℃程度であるが、搬送中に冷却され膜厚測定時には通常
管端で５０℃、管中央部で１００℃前後の温度となる。Temperature sensor 8 is installed in a non-contact position above the measurement point of the steel pipe l.
is installed, and the temperature of the coating film on the steel pipe 1 is measured by the temperature sensor and the temperature measuring device 9. Immediately after completing polyethylene coating, the surface temperature of the coated steel pipe is 200℃.
℃, but it is cooled during transportation, and when measuring the film thickness, the temperature is usually 50°C at the end of the tube and around 100°C at the center of the tube.
このようにオンラインの超音波膜厚測定では管端と管中
央部とで被覆膜温度が異なるため、この被覆膜内を伝播
する超音波の音速が異なり、このままでは測定誤差が大
きい。本発明では温度測定装置９で測定した膜厚測定点
の温度および超音波膜厚測定装置４で測定した膜厚が膜
厚補正装置ｌＯに人力され、この膜厚補正装置１０には
先に説明した最適な補正式によってできた膜厚補正用プ
ログラムが設定されており、これによって前述の測定膜
厚が補正され、その結果が膜厚表示装置１１および記録
計１２に表示される。In this way, in online ultrasonic film thickness measurement, since the coating film temperature differs between the pipe ends and the pipe center, the sound speed of the ultrasonic waves propagating within the coating film differs, and if this continues, measurement errors will be large. In the present invention, the temperature at the film thickness measurement point measured by the temperature measurement device 9 and the film thickness measured by the ultrasonic film thickness measurement device 4 are manually inputted to the film thickness correction device 10, and the film thickness correction device 10 is A film thickness correction program created by the optimum correction formula is set, and the above-mentioned measured film thickness is corrected by this program, and the result is displayed on the film thickness display device 11 and the recorder 12.
本発明によれば、合成樹脂被覆直後の被覆膜の厚みが非
接触で高精度にオンライン測定することができる。なお
、本発明はポリエチレン、塩化ビニール等の成型工場に
おける被覆鋼管の被覆膜厚測定、電線被覆物の被覆厚み
の測定その他一般の被榎体の厚み測定に適用して有用で
ある。According to the present invention, the thickness of a coating film immediately after coating with a synthetic resin can be measured online with high accuracy in a non-contact manner. The present invention is useful when applied to measuring the coating thickness of coated steel pipes, measuring the coating thickness of electric wire coatings, and measuring the thickness of general objects to be coated in molding factories for polyethylene, vinyl chloride, etc.
第１図は合成樹脂内を伝播する超音波音速の変化蓋と温
度との関係を示した図、第２図は本発明の実施例に係る
合成樹脂被覆膜厚測定装置の全体 ７−
構成を系統的に示した図である。
１・・・被覆鋼管、３・・・超音波探触子、４・・・超
音波膜厚測定装置、７・・・水柱、８・・・温度センサ
、９・・・温度測定装置。
１０・・・膜厚′６１＋＋定装置、１１・・・膜厚表示
装置、１２・・・記録計。
代理人 弁理士 染 川 利 吉
８−
第１図
０ ２０ ４０ ６０ ８０ １００（温 度 ｔFig. 1 is a diagram showing the relationship between the change in the speed of ultrasonic sound propagating in a synthetic resin and temperature, and Fig. 2 is an overall diagram of a synthetic resin coating thickness measuring device according to an embodiment of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Coated steel pipe, 3... Ultrasonic probe, 4... Ultrasonic film thickness measuring device, 7... Water column, 8... Temperature sensor, 9... Temperature measuring device. 10... Film thickness '61++ measuring device, 11... Film thickness display device, 12... Recorder. Agent Patent Attorney Rikichi Somekawa 8- Figure 1 0 20 40 60 80 100 (Temperature t
Claims (1)
の温度変化による被覆膜厚内の超音波音速変化を算出し
これによって前記超音波膜厚測定装置で得られた膜厚測
定値を補正する膜厚補正装置とを有することを特徴とす
る合成樹脂被覆膜厚測定装置。A coating film temperature measurement device, an ultrasonic film thickness measurement device, and a film obtained by calculating the ultrasonic sound velocity change within the coating film thickness due to a temperature change of the coating film and thereby measuring the film obtained by the ultrasonic film thickness measurement device. A synthetic resin coating film thickness measuring device comprising a film thickness correction device for correcting a thickness measurement value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6816482A JPS58186010A (en) | 1982-04-23 | 1982-04-23 | Apparatus for measuring thickness of coated film of synthetic resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6816482A JPS58186010A (en) | 1982-04-23 | 1982-04-23 | Apparatus for measuring thickness of coated film of synthetic resin |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58186010A true JPS58186010A (en) | 1983-10-29 |
Family
ID=13365843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6816482A Pending JPS58186010A (en) | 1982-04-23 | 1982-04-23 | Apparatus for measuring thickness of coated film of synthetic resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58186010A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6478184A (en) * | 1987-06-24 | 1989-03-23 | Nippon Kokan Kk | Method and device for deriving length of tubular body by utilizing acoustic wave |
| JPH02310411A (en) * | 1989-05-25 | 1990-12-26 | Sumitomo Metal Ind Ltd | Apparatus for monitoring cutting shape of bead on inside surface of pipe |
| US5204634A (en) * | 1991-03-08 | 1993-04-20 | Alcatel Espace | Phase-locked loop demodulator having loop filter controlled by lock detector |
| FR2689625A1 (en) * | 1992-04-03 | 1993-10-08 | Pont A Mousson | Method and device for thickness measurement by ultrasound and use of such a device. |
| EP0589315A1 (en) * | 1992-09-24 | 1994-03-30 | Krupp Hoesch Tecna Aktiengesellschaft | Device for measuring the coating thickness of a steel tubular article moving continuously in its axial direction |
| KR100635697B1 (en) | 2004-07-29 | 2006-10-17 | 한국표준과학연구원 | Method for thickness measurement using ultrasonics with the function of temperature correction |
-
1982
- 1982-04-23 JP JP6816482A patent/JPS58186010A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6478184A (en) * | 1987-06-24 | 1989-03-23 | Nippon Kokan Kk | Method and device for deriving length of tubular body by utilizing acoustic wave |
| JPH02310411A (en) * | 1989-05-25 | 1990-12-26 | Sumitomo Metal Ind Ltd | Apparatus for monitoring cutting shape of bead on inside surface of pipe |
| US5204634A (en) * | 1991-03-08 | 1993-04-20 | Alcatel Espace | Phase-locked loop demodulator having loop filter controlled by lock detector |
| FR2689625A1 (en) * | 1992-04-03 | 1993-10-08 | Pont A Mousson | Method and device for thickness measurement by ultrasound and use of such a device. |
| EP0589315A1 (en) * | 1992-09-24 | 1994-03-30 | Krupp Hoesch Tecna Aktiengesellschaft | Device for measuring the coating thickness of a steel tubular article moving continuously in its axial direction |
| KR100635697B1 (en) | 2004-07-29 | 2006-10-17 | 한국표준과학연구원 | Method for thickness measurement using ultrasonics with the function of temperature correction |
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