Small Diameter Deep Hole Research Articles

Removal Mechanism of Titanium Alloy Material in Ultrasound Vibration Drilling

In drilling the ultra-slim small diameter deep hole of titanium alloy, the problem of chip breaking and chip removal is common. When the drill is working normally, the ultrasonic vibration can be applied for the drill bit to cut the bit in the vibration to form a pulse. The cutting force waveform in drilling, should select the reasonable vibration frequency, amplitude, feed amount, workpiece rotation and other parameters to match, control the size and shape of the chip, get satisfactory chips, and avoid chip clogging. In this study, the ANSYS finite element simulation software was used to simulate the TC4 drilling process, and the difference between ultrasonic vibration drilling and ordinary drilling was analyzed. Drilling experiments were carried out. The experimental results show that compared with conventional drilling, ultrasonic vibration drilling has better surface quality, reduced tool wear and increased material removal rate.

The Design of Gun-Drill Sharpening Device

With the advancement of science and technology, the precision of processing mechanical parts is increasingly high demand, the increasing number of small diameter deep hole parts, which puts forward higher requirements of deep hole processing equipment and Gun-Drill sharpening devices. The gun drill needed to be repeatedly regrinding, hand grinding method cannot guarantee the optimum tool geometry, so special grinding devices are necessities. This paper designed a fast Gun-Drill sharpening device, the grinding accuracy and efficiency were improved, and the device has been applied in actual production.

Titanium Alloy Ultrasonic Vibration Micro Deep Holes Drilling

Through analyzing and comparing the ultrasonic drilling and general drilling, exported from cutting dosage and burr , etc, using the ultrasonic vibration drilling device to carry out the TC4 titanium alloy micro-hole drilling test. The ultrasonic vibration drilling more suitable than general drilling for the processing of Titanium Alloy, and solve Φ 2.0 x 20 TC4 Titanium Alloy drilling of small diameter deep hole problem. Fully embodies the advantages of ultrasonic vibration drilling.

Deep-Hole Drilling Negative Pressure Device Injection Process Simulation Analysis Based on Fluent

In the process of DF system machining the small diameter deep hole, the working parameters of negative pressure device has a great influence, including injection coefficient, chip removal of cross-sectional area ratio, discharge pressure, negative pressure number, etc. Injection coefficient has the non-linear proportional relationship with chip removal of cross-sectional area ratio, with the increasing incidence of negative pressure discharge pressure increases, as well as, increasing negative pressure number to improve chip removal have a good effect. Movement patterns of cutting fluid is simulated, energy loss of cutting fluid in the flow is studied, finding curved edge nozzle has better negative effects than straight edge nozzle. The effect of negative pressure pumping crumbs is analyzed, the injection process of negative pressure device is simulated, and the form of the fluid motion in negative pressure nozzle is got based on Fluent, which have a good guide for the actual production and machining.

A novel method for chip formation analyses in deep hole drilling with small diameters

Recent trends of downsizing and miniaturization of components, e.g. in the automotive industry for the manufacturing of fuel injectors or in the medical industry for the production of bone screws or surgical instruments, increase the importance of mechanical deep hole drilling with small diameters. Unfortunately, there are still some open challenges regarding this process. In addition to the unfavorable ratio of the cutting edge rounding to the achievable feed rates and undeformed chip thicknesses which results in significant mechanical tool loads, the control of the chip formation and the removal constitutes a major difficulty. The slender tool dimensions, especially the small cross sections of the chip flutes, necessitate a favorable chip formation to achieve the required process safety and productivity. Therefore, analyses of the chip formation, when machining difficult-to-cut materials provide the means for an effective process design. This analysis, however, is particularly difficult due to the closed operating zone. Quick-stop devices used for the chip formation analyses so far are limited in the tool diameter respectively the revolution speed. Furthermore the informative value is limited, because a quick-stop test takes a significant time to stop and thus the instantaneous cutting conditions during the tool retraction are altered. To overcome these restrictions, a new method for the analysis of the chip formation in small diameter deep hole drilling is presented in this paper. It is based on the utilization of a high-speed camera and tailored material samples. The experimental set-up and the results of first analyses conducted under minimum quantity lubrication are presented. The chip formation process is analyzed for the single-lip gun drilling of the nickel-based alloy Inconel718 and the bainitic steel 20MnCrMo7.

Study on Chip-Breaking Technology for Numerical-Control Varying-Feed Drilling of Deep Hole

In the drilling process for deep hole, the continuous chips often jam up due to the difficulty of chip removal, and the chips cause problems such as tool breakage and deterioration of the surface quality. The measures of chip removal must be adopted, especially for small diameter deep hole, the chip removal space is limited and thickness and length of chips can directly influence the chip removal, the chip size are required as a precondition for chip removal. In this study, the feed is periodically varied in numerical control machine, and the length of chip can be controlled, then the chip breaking is realized with no addition special chip breaking mechanism, which combines with negative pressure suction mechanism for chips, and solves the problem of chip breaking and removal.

Study on Drilling Method of Small Diameter Deep-Hole of Titanium Alloy by Using DF of Gun Drill

By the characteristics of gun drill and the mechanisms of DF (Double Feeder) system of outside the chip, and analyzing the processing characteristics of titanium alloy and the characteristics of small diameter deep hole, the drilling device DF system of gun drill is designed, and in order to better guarantee the accuracy of parts, the monitoring system between input oil installation and gun drill fixture are designed also. The device of drill the small diameter deep hole of titanium alloy, the value of surface roughness of the parts are Ra3.2-0.4μm and the phenomenon of the ring scratches eliminated.

Study on Small-Diameter Deep–Hole Vibratory Drilling of Difficult-to-Cut Materials

To solve the problem of drilling small-diameter deep-hole on difficult-to-cut materials, a kind of DF system combined with low frequency axial vibratory drilling was used. Its vibratory frequency was controlled by a frequency converter and could be adjusted continuously on-line. An inner chip removal deep-hole bit with dimension Φ8.95×500mm was developed and the material of the cutting tip was carbide alloy. Then, the drilling experiment of small-diameter deep-hole on the difficult-to-cut materials 1Cr11Ni4NMo was done. It can be found in the experiment that the chip remove was smooth, the cutting force was little, the cutting tool wear was light, the process of drilling was stable, and many factors of interfering roughness could be canceled or lightened effectively. The results show that DF vibratory drilling system can improve the machining precision and increase efficiency.

Design and Research of Amplitude Transformer in Ultrasonic Vibration Drilling System

The ultrasonic vibration drilling presents superior technology effect than common methods in small-diameter deep hole machining areas, and can improve the machining quality and efficiency remarkably. The amplitude transformer usually is designed by users according to the requirement of production. Thus the design and manufacturing of amplitude transformer and the realization of the resonance of device are key problems in ultrasonic vibration drilling system. In this paper, we firstly analyzed the structure of amplitude transformer in the axial ultrasonic vibration drilling, and then designed and manufactured the composite amplitude transformer for small-diameter deep holes in the ultrasonic vibration drilling. After we carried out the test in the sound vibration system, the result indicated that the resonance of the sound system could be satisfied and the demand of small-diameter deep hole drilling could be met.

The Optimization of Cutting Parameter of Machining the Small Diameter Deep Hole on Austenitic Stainless Steel

In this paper, objective function for the highest productivity and longer life of the twist drill is built. Though using Materlab software to draw the curves of the changes of feed, spindle speed, tool life and productivity, a way to find the better cutting parameters of machining the small diameter deep hole on the SUS316 austenitic stainless steel with the twist drill is introduced. The better cutting parameters are obtained.

工作機械操作における能動感覚フィードバック 微細加工作業における切削力の聴覚・力覚フィードバックの効果

In various manufacturing processes, manual tasks by human operators are lately seen through new eyes by virtue of flexible handling ability to a wide range of object. For this ability, the information acquired through their sense organs during operation is considered to play an important role. Conversely, when the operators acquire little sensory information, or when “Sensory Feedback” does not work well, they cannot fully show their ability. In this research, focusing on minute cutting operation with a manual machine tool, a device which translates machining state detected through engineering sensors into human sensory information has been developed and its effectiveness in improvement of operating efficiency, fatigue and tool failure has been investigated ergonomically. The authors call the sensory feedback by using this device “Active Sensory Feedback.” This paper deals with active auditory feedback, active force sensory feedback and combined one. The cutting operations examined are to make a groove on a steel bar with a lathe and to make a small-diameter deep hole on an aluminum block with a milling machine. These are known as difficult and skilled machining operations, because the operators must adjust cutting force delicately so as not to break a cutting tool. So, the cutting force is adopted as the information fed back to the operator through their sensory organs. As the results, active auditory feedback was effective especially for unskilled operators. Active force sensory feedback was also effective, though auditory one was superior to it. But, any active sensory feedback was scarcely effective for very skilled operators, who could make up in the other sense what they lacked in auditory and force senses.