Shimano (Japan)

Al-Cu alloy has been widely applied to automobile products due to its light weight and high strength, but pitting corrosion easily occurs due to intermetallic compounds (IMCs) in Al-Cu alloy. Anodizing process has been conventionally performed to improve the corrosion resistance of Al-Cu alloy surface. However, IMCs in Al-Cu alloy lead to defects in anodic oxide film. In this study, refinement of IMCs in Al-Cu alloy surface by large-area EB irradiation was proposed. Experimental results show that reflectance and corrosion resistance of anodic oxide film formed on Al-Cu alloy surface are improved by refinement of IMCs with the EB irradiation.

Abstract Ball burnishing (BB) is a surface finishing process that involves moving the tool while pressing it against the workpiece under rolling contact. We investigated the effects of BB on the fatigue strength of an aluminum alloy with a semicircular slit simulating an initial surface defect. After performing BB under a typical condition, compressive residual stress was induced to a depth of 0.4 mm, with a reduction in surface roughness by 81%. Consequently, the fatigue strength increased by 22%. BB prevented the fatigue strength reduction caused by the 0.1 mm deep slit. The result indicated that BB could render the below 0.1 mm deep surface defect harmless in terms of fatigue strength. The maximum depth of surface defect that can be rendered harmless is 0.18 mm according to fracture mechanics, which is in agreement with the experimental results.

The face gear is a crossed gear similar to a hypoid gear. Owing to its compactness and good assemblability, it is used in geared motors and transmissions for helicopters. Studies on various aspects such as design, processing, and tooth modification methods have been conducted for face gears, which are typically used in fishing reels as spinning reels owing to their easy fabrication and small vibration during reel handle rotation. Because face gears without tooth flank modification are sensitive to assembly errors, the fishing reel sensation becomes unstable during mass production. Therefore, assembling and adjusting face gears to achieve a good fishing reel sensation is time consuming. Previously, tooth flank modification with a transmission error (TE)-controlled curve was used to solve this problem. The TE-controlled curve stabilized the fishing reel sensation for assembly. However, in mass production, the manufacturing error of a pinion and face gear must be considered in addition to the assembly error. In this study, we investigated the assembly and manufacturing errors when the pinion and face gear come in contact. Furthermore, we elucidated the meshing mechanism of face gear pairs under various assembly and manufacturing errors. As a result, it was confirmed that the TE-controlled curve was affected by manufacturing errors only. Moreover, a new interesting finding was obtained regarding the meshing of the face gear with a TE-controlled curve. The TE occurrence ought to be attributed to the pressure angle deviation. Hence, it is probable to replace the main cause of the transmission error with the pressure angle deviation. This consideration is the same for a cylindrical gear pair. The meshing of face gear, which was considered complicated, can be reconsidered as the meshing of a simple cylindrical gear pair. Consequently, we revealed that the TE-controlled curve is significantly useful for considering the meshing and design of a face gear pair, which is an advantageous feature.

What kind of image will you have in mind when you hear about a fishing reel? The fishing reel is a simple device that releases and winds up a fishing line. In a world of hobbies, the demand for designability and functionality is enhanced when it comes to luxury goods. A representative example of functionality is the feeling experienced during rotation of the reel (i.e., feel of a fishing reel). The feeling is a vibration, and it occurs owing to gear-pair engagement when the handle of the reel rotates. The best professional anglers have said that they can feel if it is water turbidity or the behavior of a fish from the change in the feel of the fishing reel. To satisfy their demand, we must control the accuracy of the gear to the sub-micrometer level. For this purpose, the shape of the tooth flank of the gear is precisely designed by three-dimensional computer-aided design (3D-CAD). However, anglers’ demands increase each year. To respond to these demands, in addition to improving the tooth flank accuracy, we need to research the feel of the fishing reel. Initially, we must think about what is the feel of a fishing reel. We contributed to the research of the relationship between the vibration and the tactile sensitivity of the human finger. As a result, we elucidated that tactile sensation has a high correlation with the vibration of mesh frequency that occurs owing to gear-pair engagement. Using this phenomenon, we succeeded in developing a new feature called “micro-module gear TM.” This function improves the feel of the fishing reel by adapting a small gear module. This is a technology born from an entirely new approach to the optimization of the mesh frequency. However, research on gear and sensitivity is underdeveloped. In this paper, we report some state-of-the-art studies in this underdeveloped field that improved the feel of fishing reel.

Introduction: Krüppel-like factor 4 (KLF4) is a transcription factor controlling differentiation and proliferation of vascular smooth muscle cells (VSMC). We recently showed that disruption of elongation of long chain fatty acids 6 (Elovl6), rate-limiting enzyme catalyzing the elongation of saturated and monounsaturated, suppressed VSMC proliferation and differentiation via AMP-activated protein kinase (AMPK) activation. However, little is known about the role of KLF4 in passing metabolic stress on to the regulating VSMC proliferation and differentiation. Hypothesis: We examine whether KLF4 is involved in the suppression of Elovl6-disrupted VSMC proliferation. Methods and Results: Immunohistochemical staining of aorta revealed that KLF4 expression was markedly increased in Elovl6-null (Elovl6 -/- ) mice compared with wild-type mice. Western blot analysis also showed that the KLF4 expression was markedly induced in human aortic smooth muscle cell (HASMC) with siRNA-mediated Elovl6 depletion and in Elovl6 -/- mouse aorta. Previous study demonstrated that Elovl6 depletion in VSMC altered long chain fatty acid (LCFA) composition in which palmitate was increased and oleate was decreased. Accordingly, palmitate increased and oleate decreased KLF4 expression. To clarify the effects of KLF4 on cell-cycle regulatory gene expressions and cell proliferation, we examined a siRNA-mediated knockdown of KLF4 in HASMC. The expression of SMα-actin and SM22α genes were decreased in siKLF4-introduced HASMC, and siElovl6-triggered inhibition of cell proliferation was partially recovered by concomitant treatment of siKLF4. Elovl6 depletion in HASMC markedly induced p53 phosphorylation and p21 expression, whereas depletion of KLF4 abrogated the induction of these proteins. We further identified the treatment with AMPK activator (AICAR) significantly induced KLF4 expression, whereas AMPK inhibitor (compound C) markedly inhibited the AICAR-induced or Elovl6-knockdown-induced KLF4 expression. Conclusions: Overall, our results indicate that KLF4 is activated by metabolic stress triggered by perturbed intracellular LCFA composition and AMPK-KLF4 axis plays an indispensable role in controlling VSMC proliferation and differentiation

The purpose of this study was to reveal physiological conditions of commuter cyclist from the standpoint of multiple approaches. Ten male employees (37 ± 9 yr) who usually commute by bicycle participated in this study. Global Positioning System (GPS) was used to analyze their commuting route three-dimensionally. And heart rate was recorded simultaneously to determine their exercise intensity. Blood test, oral glucose tolerance test (OGTT), and maximal aerobic test was conducted in our laboratory. Semantic differential method (SD) questionnaire was conducted to clarify their feelings during and after their commute. The results of blood test and OGTT showed that all of determined values were good and no one exceeded the standard value. GPS log showed that subjects covered 13.3 ± 7.2 km and 40 ± 20 minute with integrating 201 ± 114 meter altitude gain per commute. Heart rate data showed 129 ± 12 bpm per commute. However, subjects demonstrated higher peak heart rate during their commute ranged between 157 and 181 bpm, we determined details by frequency distribution method. The data revealed that commuter cycling was consisted by aerobic exercise with intermittent vigorous intensity exercise. Despite of such a hard exercise cycling to work, the result of SD questionnaire indicated that subjects felt briskness with less tiredness when they commute. Commuter cycling with a higher than moderate exercise intensity, could have good physical and mental effects for employees.

This research report discusses how to derive a path of contact on face gear. A sample was manufactured, in which tooth modification is taken into account, and the sample was investigated as to whether it is robust against alignment errors. It has been verified that the assembly operation can be improved along assembly line.