Coolant Hoses Research Articles

Parametrization of manual work in automotive assembly for wearable force sensing

This research aims to model manual assembly processes by parameterizing operator force readings, specifically for engine and coolant hose connections in an automotive manufacturing line. During automotive assembly, many processes are still performed manually by the human operator due to the complexity of automating the process or product with current technology. Processes include completing hose connections and subsequent “push–pull–push” verification testing. Manual work introduces an opportunity for human error because of natural variation when completing tasks; even a slight inconsistency in operation can lead to an incomplete or missed process. These incomplete processes can pass post-production checks, such as a pressure test, but later loosen and fail, causing rework or warranty issues. To minimize human error, operator force is parameterized to provide real-time feedback to the connection status. The operator force was chosen to classify connections and to verify testing quantitatively. The parametrization was completed by partitioning the shear and normal forces using custom fixtures, with shear being the primary force type required by the process. The varying finger and hand engagement for the different connector locations were factored into the parametrization to encompass a broader range of manually completed tasks. It was found that operator forces in finger engagement for manual assembly could be effectively represented by a limited set of measurable parameters.

Proposed optimal maintenance intervals for milling machine using risk based maintenance and analytical hierarchy process at manufacturing plant

PT IIS is an outsourcing company that offers manufacturing spare parts and dies forging. In producing dies forging product PT IIS uses Milling machines, lathes, and CNC 20-L Liquy Hising machines. Based on machine failure data, milling machines suffered a total of 27 times failure during the 2018-2019 period, the frequency of failure will affect the production process and resulted in large maintenance costs. Thus, it takes more observation regarding the maintenance of the Milling machine. The method used for research is Risk-based maintenance (RBM) which aims to estimate and minimize risks arising from failure. The results of collection and processing using RBM revealed that Milling machines with 2880 hours maintenance intervals had a total risk of Rp6,395,124.84 with the percentage of 0.67% exceeding the company’s risk tolerance limit of 0.50%. Using the approach to minimizing risks, the proposed maintenance interval is 1100 hours and is at the company’s risk acceptance criteria of 0.50%. This study also uses the Analytical Hierarchy Process (AHP) method which decides the maintenance policies that are tailored to the company’s conditions, for Spindel components and rags using condition-based maintenance, and coolant hose components using time-based maintenance.

The Combined Effect of High Temperature and Ethylene Glycol (EG) on Polyethylene Terephthalate (PET)-Reinforced Coolant Hose Failure in Combustion Engines

Cooling systems in internal combustion engines can be based on liquid, air, or a combination of both. This study presents two cases of cooling system failure in a four-stroke internal combustion engine cooled by a combination air and liquid cooling system with ethylene glycol as coolant. The coolant elastomer hoses in these engines are made of PET-reinforced silicone rubber braid. The decline in mechanical performance of such elastomer hoses following exposure to extreme temperature and certain liquids is a known phenomenon. In this study, the effect of environmental conditions on hose tensile strength was examined using fractography, and analytical and mechanical tests under various ambient conditions and different combinations of oil, air, and coolant. Engine temperature was tracked in several locations in the engine. The signs of hose failure were exhibited as changes in color, swelling, fiber separation, or disintegration. Engine temperature measurements showed that the failure occurred in highest temperature location. It also indicated that the high temperature is a result of the proximity to the exhaust manifold which is located directly below the coolant hose. This study demonstrates for the first time that the exposure to a high temperature and to ethylene glycol as a combination is a critical factor in compromising the mechanical properties of PET-reinforced silicone rubber. Moreover, it is destructive than exposure to either high temperature or ethylene glycol separately. In fact, this study shows that combined exposure to ethylene glycol and a high aging temperature (200 °C) caused a decrease of a 79% in tensile strength and a 61% decrease was noticed as a result of exposure to high temperature and air. Designers of engine cooling systems and similar applications can utilize the results of this study when deciding on cooling system location, type of thermal insulation, coolant liquid, and hoses material.

Life cycle cost analysis of a computerized numerical control machine tool: a case study from Indian manufacturing industry

PurposeLife cycle cost (LCC) analysis is one of the key parameters in designing a sustainable product or system. The application of life cycle costing in the manufacturing industries is still limited due to several factors. Lack of understanding of LCC analysis methodologies is one of the key barriers. This paper presents a generalized framework for LCC analysis of repairable systems using reliability and maintainability principles.Design/methodology/approachThe developed LCC analysis framework and stochastic point processes are applied for the analysis of a typical computerized numerical control turning center (CNCTC) and governing equations for acquisition cost, operation cost, failure cost, support cost and net salvage value are developed. The LCC of the CNCTC is evaluated for the renewal process (RP) and minimal repair process (MRP) approach.FindingsThe LCC analysis of the CNCTC reveals that, the acquisition cost is only 7.59% of the LCC, whereas the operation, failure and support costs dominate and contribute nearly 93% of the LCC. The LCC per day for RP requires additional US$ 1.03 than that for MRP. The detailed LCC analysis of the CNCTC identifies the critical components of CNCTC and these components are: spindle motor, spindle motor cooling fan, spindle belt, drawbar, spindle bearing, oil seals, hydraulic hose, solenoid valve, tool holder, lubrication pump motor system, lubrication hose, coolant pump motor system, coolant hose, supply cables, drive battery.Originality/valueThe developed framework of LCC of a repairable system can be applied to any other repairable systems with the appropriate modifications. LCC analysis of CNCTC reveals that the procurement decision of a product or system should be based on LCC and not only on the acquisition cost. The optimum utilization of consumables such as cutting tools, coolant, oil and lubricant can save operation cost. Thus, use of high-efficiency electric motors and the usage of recommended consumables can prolong the life of several components of a system. Therefore, due consideration and attention to these parameters at product design stage itself will decrease failure and support cost and ultimately its LCC.

Ultra High Molecular Weight NORDEL™ EPDM for TPV and Low Hardness Molded Goods Enabled by Advanced Molecular Catalyst

Ethylene propylene diene synthetic rubber (EPDM) is the material of choice to manufacture various automotive parts due to its natural stability and resistance to heat, UV, and ozone. In addition, its polyolefinic nature results in consistent processing and good filler and oil acceptance for use in compounds ranging from automotive weather sealing, under-the hood belts and coolant hoses, roofing membranes, gaskets and other general rubber articles. Building on a fifty-year history of performance, Dow’s Advanced Molecular Catalyst (AMC) and process technology advancements enable highly tailored design of EPDM molecular architecture including, composition, molecular weight and long chain branching (LCB). This is not only resulting in capacity efficiency and sustainable production but also increasing design options of the molecular features to tailor the performance for high in-use efficiency. This paper summarizes a new ultra high molecular weight (UHMW) NORDEL™ EPDM product and its potential applications. Case studies will be presented to showcase its use in thermoplastic vulcanizate (TPV), black color low hardness compounds, and lighter color (gray) washing machine gasket application. The EPDM polymer structure, compound formulation, mixing performance, compound rheology, vulcanization characteristics, and mechanical property improvements are discussed.

A Study on the Improvement of the Separation Phenomenon of Coolant Hose in the Tracked Combat Vehicle

A Study on the Improvement of the Separation Phenomenon of Coolant Hose in the Tracked Combat Vehicle

Reliability analysis of CNC turning center based on the assessment of trends in maintenance data

PurposeThe paper presents reliability, maintainability and life cycle cost (LCC) analysis of a computerized numerical control (CNC) turning center which is manufactured and used in India. The purpose of this paper is to identify the critical components/subsystems from reliability and LCC perspective. The paper further aims at improving reliability and LCC by implementing reliability-improvement methods.Design/methodology/approachThis paper uses a methodology for the reliability analysis based on the assessment of trends in maintenance data. The data required for reliability and LCC analysis are collected from the manufacturers and users of CNC turning center over a period of eight years. ReliaSoft’s Weibull++9 software has been used for verifying goodness of fit and estimating parameters of the distribution. The LCC of the system is estimated for five cost elements: acquisition cost, operation cost, failure cost, support cost and net salvage value.FindingsThe analysis shows that the spindle bearing, spindle belt, spindle drawbar, insert, tool holder, drive battery, hydraulic hose, lubricant hose, coolant hose and solenoid valve are the components with low reliability. With certain design changes and implementation of reliability-based maintenance policies, system reliability is improved, especially during warranty period. The reliability of the CNC turning center is improved by nearly 45 percent at the end of warranty period and system mean time between failure is increased from 15,000 to 17,000 hours. The LCC analysis reveals that the maintenance cost, operating cost and support costs dominate the LCC and contribute to the tune of 87 percent of the total LCC.Research limitations/implicationsThe proposed methodology provides an excellent tool that can be utilized in industries, where safety, reliability, maintainability and availability of the system play a vital role. The approach may be improved by collecting data from more number of users of the CNC turning centers.Practical implicationsThe approach presented in this paper is generic and can be applied to analyze the repairable systems. A real case study is presented to show the applicability of the approach.Originality/valueThe proposed methodology provides a practical approach for the analysis of time-to-failure and time-to-repair data based on the assessment of trends in the maintenance data. The methodology helps in selecting a proper approach of the analysis such as Bayesian method, parametric methods and nonparametric methods.

Electrochemical degradation tests on a carbon-black-filled ethylene propylene diene monomer rubber under tensile strain

Rubber hoses play an important role as a path for carrying the coolant liquid between the radiator and the automotive engine. However, the rubber hoses are apt to deteriorate because of the formation of a galvanic circuit between the rubber hose, the coolant water and the fitting metal part of the engine. Such electrochemical degradation can damage the inner skin of the hose in contact with the coolant liquid heated by the working engine, which often leads to leakage of the coolant water and thereby to hose failure. An ethylene propylene diene monomer rubber has mostly been utilized as the material for the coolant hoses of automotive engines because of the strong resistance to various environmental stresses. This study conducted experimental simulation tests and evaluation of the electrochemical degradation behaviours of the carbon-black-filled ethylene propylene diene monomer rubber used for the coolant hoses. The tests were performed by considering the actual circumstances together with the combined thermal, tensile strain and electrostatic voltage loadings on the rubber hoses. The behaviour of the change in the electrical resistance of a specimen and, thus, the apparent decrease in the current were analysed quantitatively. An Arrhenius life prediction by using the decrease in the current was reasonably expressed for the accelerated life tests. Many microhole networks were thus formed in the skin part of the specimen by the microbreaks in the carbon-black phase and the scission of the sulphur cross-links. The coolant liquid penetrated significantly into the skin, which resulted in a considerable swelling of the skin. The larger the strain application to the rubber, the lower are the strength and the elongation at the breaking point. An exponential index parameter can represent quantitatively the behaviours of the decreases in the mechanical properties used for accurate life prediction.

216 A process model of coolant hose factory for lean manufacturing simulation

Lean Manufacturing (LM) is a production practice to eliminate waste by considering the expenditure of resources for any goal other than the creation of value for the customer to be wasteful. For achieving lean production, typical lean principles are already established as a set of LM tools, such as Single minute exchange of die (SMED), Kanban, total productive maintenance, etc, and some of these tools are also available as computer software. Even though these tools could resolve many manufacturing issues, expected results by LM tools cannot be seen before their implementation. This study focuses on a process simulation approach to see the effectiveness of LM tools before their implementation. This study designed a process model of a coolant hose manufacturing (CHM) factory and implemented its simulation model. This paper presents the implemented simulation model and shows how it could be used to see the effect of LM tools using an example of SMED LM tool.

Viewpoint: International Traffic in Arms Regulations—Controversy and Reform

The International Trade in Arms Regulations (ITAR) have, for decades, played a crucial role in shaping the movement of sensitive technology from the United States to the world. Originally intended to ensure military dominance, the ITAR regime is seen by some as stifling the competitiveness of American industry. A list known as the United States Munitions List (USML) contains the items subject to the ITAR export controls. This list includes clearly dangerous military technology such as missile navigation systems and fighter jet avionics but also includes seemingly benign items, such as coolant hoses or tape recorders for spacecraft. Among the items considered controversial are a number related to the space industry. An incident in the early 1990s began a jurisdictional tug of war. The United States strengthened its grip on the export of space technology. In the last two decades, some have observed a decline in the competitiveness of American industry. The content of the USML should be reviewed based not on the historical “catchall” approach, but rather based on a “military intent-based” or “military capability-based” approach. This will improve the competitiveness of the U.S. space industry without sacrificing national security.

Extrusion-Shaping of Curved Hose Reinforced with Short Cellulose Fibers

Abstract A new development in hose technology, the direct shaping of curved hose reinforced with short fibers at the extrusion die, is described. By moving the inner and outer portions of the tube die out of concentricity in a programmed sequence, the extrusion direction can be made to deviate from the machine axis and thus to produce bends in the hose. This process has been demonstrated on planar S-bends of a 38 mm hose. Bend radii as tight as 13 mm to the inside of the bend are feasible. Such a hose might find various industrial applications. Performance characteristics are similar to cord reinforced coolant hoses. The reproducibility of the die motions and timing sequences to produce the hose shapes are maintained by a digitally controlled hydraulic cylinder that is driven through a stepper motor. The driver for the stepper motor could involve hard-wired or microprocessor circuitry. All of the components for this system are commercially available with the exception of a customized extrusion head to accomodate the mounting and connection of the hydraulic cylinder. This unique process for producing curved hose is contingent upon the use of short fiber reinforcement for several reasons: (a) The reinforcement must be present in the stock before it is extruded. (b) The dispersed short fibers give the hot extruded hose structural integrity to minimize shape distortion before cure. (c) The hoop-wise fiber orientation pattern produced in the novel conically expanding die is augmented by additional reinforcement in the thinner hose wall that occurs on the inside of the bend. An important consequence of the third item above is that the curved hose sections display practically the same burst strength as a straight section, despite the wall thinning that occurs as a result of offsetting the die and pin. The production and performance of these short-fiber reinforced curved hoses can be rationalized in terms of the fluid and mechanical behavior of short fiber composites.

A cryoprobe and cryoplate for reversible functional blockade in the brains of chronic animal preparations

1. 1. An easily constructed cryoprobe is described for reversible functional blockade of subcortical neural structures in chronic animal preparations. 2. 2. A cryoplate is described for blockade of cortical regions of various sizes and shapes. 3. 3. The use of Luerlok hypodermic needle connectors was found useful for making connections of the cryoprobes to the coolant hoses. 4. 4. The temperature-monitoring thermocouple reference junctions were implanted on the animal to eliminate the use of bimetallic thermocouple connectors and cables.