使用超小型光纤探头的喷射喷嘴干涉测量技术

161 浏览量更新于2024-08-27 收藏 3.87MB PDF 举报

"Interferometric measurement of injection nozzles using ultra-small fiber-optical probes" 这篇科研文章探讨了在精密测量领域中的一个技术挑战：如何对直径小于500微米的孔洞进行高精度测量。传统的生产计量技术无法满足这种微小尺寸的检测需求。为解决这一问题，作者介绍了一种直径仅为80微米的微型光纤探针。这种探针采用了低相干干涉测量技术，这是一种非接触式的高精度测量方法，特别适用于微小孔洞形状偏差的检测。低相干干涉测量是光学计量中的一种关键技术，它利用光的干涉现象来测量物体表面的微小形变或距离变化。通过将一束短相干长度的光源（例如激光）分成两路，一路经过被测物体，另一路作为参考，两束光在探测器上重新会合并形成干涉图案。根据干涉图案的变化，可以精确地计算出物体表面的微小形变，从而实现高精度的尺寸测量。在文章中，这种微型光纤探针被应用于注射喷嘴的质量检验。注射喷嘴是汽车、航空航天和精密制造行业中不可或缺的组件，其几何精度直接影响到产品的性能和寿命。由于喷嘴内部的孔径非常小，传统的测量工具难以触及，因此这种光纤传感器的应用具有重大意义。实验结果显示，该光纤传感器能够成功地对喷嘴内部的孔洞形状进行精确测量，证明了其在高精度零件质量检测方面的潜力。此外，文章提及的"圆度"和"光纤光学"是两个关键标签。圆度是指孔洞或表面的几何形状接近理想圆形的程度，对于注射喷嘴这类要求严格几何精度的部件来说至关重要。而"光纤光学"则强调了探针的核心技术，即利用光纤传输和处理光信号的能力，实现微小空间内的光学测量。这篇研究展示了超小型光纤探针在微尺度测量中的优势，尤其是在检测直径小于500微米的孔洞如注射喷嘴时，能提供前所未有的精度和可操作性。这不仅有助于提升产品质量，也为未来微纳米制造领域的计量技术发展提供了新的可能性。

COL 9(7), 071202(2011) CHINESE OPTICS LETTERS July 10, 2011

Interferometric measurement of injection nozzles using

ultra-small fiber-optical probes

Tilo Pfeifer

1,2

, Robert Schmitt

1,2

, Niels K¨onig

1∗

, and Guilherme Francisco Mallmann

Fraunhofer Institute for Production Technology Steinbachstr. 17, 52074 Aachen, Germany

Lab oratory for Machine Tools and Production Engineering of RWTH Aachen University,

Steinbachstr. 19, 52074 Aachen, Germany

∗

Corresp onding author: niels.koenig@ipt.fraunhofer.de

Received December 1, 2010; accepted February 18, 2011; posted online May 18, 2011

The measurement of b oreholes with diameters smaller than 500 µm is a demanding task that cannot be

p erformed using state-of-the-art production metrology. In this letter, a miniaturized fiber probe with

a diameter of 80 µm is presented. A probe is used for low-coherence interferometry to conduct highly

precise measurements of form deviations of small boreholes. Measurements conducted in nozzles are also

presented. The results prove the potential of the fiber-optical sensor for quality inspection of high-precision

parts, such as injection nozzles, for common-rail diesel engines.

OCIS codes: 120.3180, 120.6650, 060.2370.

doi: 10.3788/COL201109.071202.

The shape of spray holes in modern fuel injection nozzles

for diesel engines is a key factor in minimal pollutant

emission and economic fuel combustion. Any devia-

tion from its design shape significantly affects spray

breakup, leading to unequally distributed ﬂow and pres-

sure changes

[1]

The measurement of spray holes poses a major chal-

lenge towards modern production metrology, because

these holes can have diameters of as small as 150 µm,

with a tendency towards even smaller diameters in future

systems. There are several measuring principles for the

inspection of injection nozzles. These can be categorized

into tactile

[2]

(or with a gauge), opto-tactile

[3]

, optical

[4]

and electrical principles

[5]

. Common measurands include

diameter and fuel ﬂow. Only a few principles offer the

possibility for more than just point-wise probing. A

fiber-based approach, which can be used to scan inside

small boreholes, has been described in Ref. [4]. Due

to many factors, including the small measuring range

of ∼30 µm, complex and expensive heterodyne inter-

ferometer set up, and restrictive patent situation, this

fiber-based approach has not been as established as the

other methods mentioned.

This letter presents an interferometric measurement

system based on fiber-optical components, which can be

minimized for the inspection of injection nozzle spray

holes. Evaluation measurements were conducted with a

spark-eroded micro-hole array.

The measuring principle is based on low-coherence

interferometry. The key element of the system, which

has been developed at Fraunhofer Institute for Produc-

tion Technology, is the fiber-based sensing probe and

fiber-coupled interferometric evaluation unit (Fig. 1).

Both elements utilize the interferometric principle: the

fiber-based Fizeau interferometer is used as sensing probe

and encodes the measurement distance, which is then

decoded in the Michelson interferometer. Two superlu-

minescent diodes (SLD) are coupled into the system as

a supercontinuum, low-coherence light source with two

shifted wavelengths for additional beat frequency. Single-

mode couplers carry the light to the sensing probe, where

Fresnel reﬂection divides the light into a reference and

a measuring beam. The optical path difference (OPD)

between these beams is compensated in the Michelson

interferometer by an appropriate length difference be-

tween beam splitter and reference mirror and the tilted

mirror, respectively. The characteristic interference pat-

tern is then detected by a charge-coupled device (CCD)

line camera and processed by a computer. The distance

of the measuring object is correlated with the lateral

position of the fringe center on the CCD chip, leading to

a pixel value that encodes the distance.

Working distance and measuring range can be adjusted

with the angle and distance between the tilted mirror

and the beamsplitter cube. The fact that the fiber-based

Fizeau interferometer is build up as common-path inter-

ferometer is an outstanding system advantage. This is

because measurement and reference paths are exposed to

the same thermal conditions that minimize thermal drift

due to dissimilar fiber-lengths. Furthermore, there are

no mechanical elements required, such as linear stages

or piezoelectric actuators, for balancing or varying the

OPD. The system provides a variable working distance of

around 100 µm and a measuring range of approximately

160 µm.

Fig. 1. Setup of the fiber-optical interferometer.

1671-7694/2011/071202(4) 071202-1

° 2011 Chinese Optics Letters

下载后可阅读完整内容，剩余3页未读，立即下载

weixin_38660624

粉丝: 3
资源: 939

使用超小型光纤探头的喷射喷嘴干涉测量技术

matlab中算法实现代码实现原理-real-time-interferometric-measurement-control-for-pho

Spectral-domain measurement of beat length in polarization-maintaining fibers

Measurement of single cycle and sub-cycle pulse duration

Transmissive Interferometric Display with Single-Layer Fabry-Pérot Filter

Non-scanning, non-interferometric, three-dimensional optical prof ilometer with nanometer resolution

Asymmetric Fabry-Perot interferometric cavity for fiber optical sensors

Energy reduction: a technique for seed-injection locking of single-axial-mode Q-switched Nd:YAG laser

Neural-network-assisted femtosecond laser pulse duration measurement using two-photon absorption

Study of terahertz interferometric imaging using optical techniques

Dispersion measurement of Yb-doped fiber by a spectral interferometric technique

最新资源