Dry Liners Research Articles

Analysis of out-of-round deformation of a dry cylinder liner of a non-road high-pressure common-rail diesel engine based on multi-field coupling

The deformation of cylinder liner directly affects the sealing performance of the friction components in internal combustion engines, resulting in high oil consumption, engine power loss, and high-particulate matter emissions. Previous research works focused more on deformation of the wet vehicular cylinder liners, however, the effects of different loads on the dry liner deformation is not clear yet. A non-road high-pressure common-rail diesel engine was selected as the research object, and a coupled model of the engine was developed based on fluid–solid coupled heat transfer theory. After the accuracy of the model was verified by temperature measurement of the cylinder head and cylinder liner, deformation of the dry cylinder liner was studied. The results show that the axial and radial deformations of the cylinder liner are not uniform under the bolt preload condition. Large deformation occurs at the first liner and fourth liner, with the maximum deformation occurring at the top of fourth liner for 10.14 μm. Under the condition of thermal load, the temperature of cylinder liner exhibits a distribution of three-segments from the top to bottom. The liner deformation is not uniform, and the maximum deformation occurs at the top of the fourth liner for 304 μm. The radial deformations of all four cylinder liners present a symmetrical structure of a “heart” shape with respect to the centerline of the second and third cylinders. The axial deformation of each liner exhibits a “barrel” shape which is convex in the middle and narrow at the two ends.

Adenosine triphosphate bioluminescence for hygiene testing of rubber liners and tubes on dairy farms

Prevention of biofilm formation in milking equipment is important to ensure good hygiene quality of raw milk. Key factors to achieving good results are a successful cleaning procedure and a method to check the cleanliness of milking equipment surfaces. Adenosine triphosphate bioluminescence is a fast and easy method for investigating bacterial contamination of surfaces. However, previous studies on the potential of ATP bioluminescence to assess the hygiene status of milking equipment have been hampered by lack of a validated test procedure. The aim of this work was therefore to establish a test procedure for assessing the cleanliness of milking equipment using ATP bioluminescence, and apply the method on-farm to study the hygiene status of aging rubber material in milking equipment. In developing the test procedure, the effects of sampling location in tubes and liners, sampling of dry versus wet barrels, milking point in the parlor, and acid or alkali detergent on ATP values were investigated. The results showed that, to obtain reproducible results, replicate sampling from the same milking points in the parlor is important. For milk tubes, samples should preferably be taken from the milk meter side, for liners on the inside of the barrel. For best results, sampling should be performed after use of alkali detergent. No beneficial effect was observed of sampling dry liner barrels, so sampling in the standardized test procedure is performed directly after cleaning. The standardized test procedure was used on 3 different commercial farms and sampling was initiated after replacement of old rubber parts. On one of the farms, additional sampling was performed to evaluate total bacteria count and determine the association with ATP level. The results suggest that, provided an efficient cleaning procedure is used, the hygiene quality of milking equipment can be maintained during the recommended lifetime of the rubberware. However, due to occasional variation in cleaning efficiency between milking points and liner barrels, random sampling on single occasions can lead to incorrect conclusions. Replicate sampling over time is therefore important for correct interpretation of ATP bioluminescence data. If ATP levels are very high, complementary sampling for total bacteria count should be used to verify that the level is due to bacterial contamination, and not other organic ATP-contributing material (e.g., milk residues).

B19 非線形FEAを用いたドライライナ構造シリンダブロックのトップデッキ隅部における静応力低減に関する検討(OS1 機械要素の強さと性能向上VI)

B19 非線形FEAを用いたドライライナ構造シリンダブロックのトップデッキ隅部における静応力低減に関する検討(OS1 機械要素の強さと性能向上VI)

Predict and Assure the Matchable Degree in Selective Assembly via PCI-based Tolerance

Selective assembly is a method to achieve high precision fit using low precision parts. The current practices in selective assembly lack a physical process model to guide the design and process of mating parts, consequently, selective assembly is often a nightmare for manufacturing people and historically an event to be avoided. Process capability indices (PCIs) are the widely accepted process parameters, functioning as a measure of process performance, such as process centering, process spread, process bias, etc. In this paper, the concept of PCI-based tolerance is proposed as an interface between quality requirements and statistical process control (SPC) parameters. An analytical model involving PCI-based tolerance is developed to predict and assure the matchable degree in selective assembly. A detailed case study of the fit of dry liners and cylinder blocks in a diesel engine is presented. As matchable degree and other process quality requirements can be assured at the stage of design by introducing PCI-based tolerance, the process of selective assembly can be improved significantly as an effective way to achieve precision assembly with economical manufacturing processes.

Effect of wet and dry cellulose ring liners on setting expansion and compressive strength of a gypsum-bonded investment

Effective setting expansion of gypsum-bonded investments is influenced by many variables. The purpose of this study was to determine the effect of using either water-saturated or dry cellulose ring lining material on (1) the fit of castings on a steel die and (2) the compressive strengths of investment cores using either type of liner. The mean gingival space in the water-saturated liner group was 0.241 ± 0.048 mm and was 0.071 ± 0.029 mm in the dry liner group ( p < 0.001). The compressive strengths of investment cores from the dry liner group were 36.5% greater than those of cores from the water-saturated liner group. The results demonstrated that the use of dry liners may improve the fit of castings to dies.

Study on cylinder bore deformation of dry liner in engine operation

Abstract Cylinder bore deformation of reciprocating engines causes increasing lubricating oil consumption, abnormal wear, etc. However, prediction of deformation on a dry liner has not been made because of the complication of its structure. This study investigates the mechanism of dry liner deformation in actual engine operating conditions. The effect of clearance between the liner and the block, and in particular the mechanism of thermal deformation, were found through measurement of bore deformation by using a unique measuring device, which has a turning piston developed by the authors, and through FEM calculation. Lubricating oil consumption related to bore deformation was also studied.

Analysis of Epithermal Neutron Beam Experiments at the Hifar Reactor

A calculated model of the entire core of the DIDO class reactor HIFAR has been used to analyze epithermal neutron beam experiments. In the experiments, an off-center fuel element was replaced by a dummy fuel element voided by a dry liner in which an aluminium spectrum shifter was suspended at core center to extract the beam. Various combinations of the filter materials aluminum, iron, sulfur, titanium, and cadmium were inserted near the top of the dry liner, and liquid argon was placed in a cryostat above the dummy element. Reaction rates were measured in a fission chamber, sandwiched between various thicknesses of polyethylene, in order to assess the accuracy of the calculational model for different regions of the neutron energy spectrum of the beam. The neutron source distribution of the HIFAR core was obtained from a three-dimensional diffusion calculation, with burnup-dependent fuel compositions and fission products included, using the AUS modular code scheme. Argon cross sections were generated from ENDL-84 data and resonance parameters taken from Neutron Cross Sections (1984). A whole-core MCNP source calculation was used to analyze the experiments giving good agreement between measured and calculated reaction rates. This whole-core model of HIFAR may be applied with confidence more » to predict the performance of filtered beams for boron neutron capture therapy and also to other HIFAR calculations. « less

Setting expansion of investment and accuracy of castings

Setting expansion of 4 phosphate-bonded investments was measured under 3 different conditions: a hygroscopic condition, a condition using a ring lined with a wet liner and a condition using a ring lined with a dry liner. Accuracy of castings of a Ni−Cr alloy made in each of the 4 investments in rings lined with a wet liner was measured. One investment exhibited negative potential for hygroscopic expansion. Expansion of all investments in wet-lined rings was not significantly different from their expansion under the hygroscopic condition. There was no significant difference in setting expansion between the investments when a wet liner was used. Significant differences in accuracy existed between castings produced in the different investments using a wet liner. The correlation between the setting expansion of the investments using a wet liner and the accuracy of castings produced using a wet liner was not high and was not significant. Comparison between investments with regard to their ability to produce accurate castings in terms of mould expansion by measurement of setting expansion is of no value.