The impact of blade rupture on productivity will be immeasurable. Rich Bauer, production coordinator at McGill Machine Works, experienced this during a rough milling operation, but with cutting tools that reassemble the equipment Today, Ingersoll has achieved 80% growth in production capacity and has eight times the tool life, according to Bauer.
Bauer's machine shop has a total of 10 employees and operates 22 hours a day, 5 days a week, while Bauer's main job is to rough-cut high chromium steel into D-2 forgings for nailing Easy-wear parts on the machine Rough-cut rectangular finished part dimensions are: 2.5in (1in = 25.4mm) long, 1.25in wide and 0.350in thick (0.194in narrowest). In roughing, Milling and side-to-side milling of raw materials reduces the weight by more than half, which takes up over 80% of the entire machining cycle, followed by drilling, grooving and eventually cornering of the car , To eliminate the existence of stress concentration angle.And then the parts were heat treatment, so that it reached 60 ~ 62HRC, and coated with oxide coating.
Figure 1 McGill Machine Works Improves Rough Milling Operations With New Di-Pos Hexa Face Mills from Ingersoll Corporation Reassemble D-2 Stocks with Operational Difficulty Improved Tool Life and Increased Production Capacity 80%, reduce the noise level during operation, and will not cause dirty mess due to cutting fluid
Although Bauer originally used a blade designed specifically for high-chrome steel, it seemed to him that he was fortunate enough to remove five such blades before he broke them in. He attempted to reduce material removal, However, he said that it took 51 minutes to complete the entire roughing process when machining parts using the Kia vx 500 CNC vertical machining center, which used a four-point cone with a diameter of 2 in Flat surface milling cutter with synthetic coolant and set to 625sfm, 10in / min and depth of cut of 0.050in. Under these conditions, one out of every 4 to 5 inserts will fragment. Increase cutting depth This can lead to clogged chips, which often produce click noises, as well as powdered chips - a feature of machining hard parts.
'The damage to our tools is a major challenge for us, but we are also looking to increase our productivity,' said Bauer, a promotional email from Ingersoll that introduced the company's newly manufactured high-efficiency Di -Pos Hexa Surface Mills After a tentative communication with the field representative Jarett Johnson, Bauer received a new tool along with the recommended parameters and recommendations for stopping the coolant.
Figure 2 This type of Di-Pos Hexa free-form face mill, manufactured by Ingersoll Corporation, cuts under a hard metal surface to produce uniform chips and removes the cutting heat generated during machining of the tool and workpiece. The advanced coating reduces friction and provides thermal insulation to the blade substrate
Bauer said he could not immediately pull out to test the new tool, but decided to give it a try after he took the accompanying parameters for the next few days, although Johnson and Mike Toleman, dealers from Quality Tools and Abrasives, tried Help, but Bauer does not think it's easy to reassemble, so there's no need for hands-on guidance.
In the experiment, he adopted the parameters recommended by Johnson and stopped using the coolant as he proposed: For a 2-in. Diameter di-Pos Hexa tool with six cone angles, the settings are: 500sfm, 40in / min and a depth of cut of 0.075 in. This type of tool runs only 28 minutes and extends the life of the insert by a factor of six. Previously, surface finishing has also been improved and controlled at 30 to 60 microinches At the same time as the material removal rate is increased, the spindle load cell rarely exceeds 50% again and the noise level during operation is also reduced. The resultant chips show a uniform C-shape, indicating that this is a Full of easy-cut operation.
Dry processing on hard materials may seem impossible, but cutting fluids tend to create thermal shocks that can damage existing high-performance blade coatings, Johnson said. "In addition, Di The -Pos Hexa tool runs at a very low temperature and therefore does not require cutting fluid at all.
The easy-to-cut geometries of the insert are noted in Figure 3. According to Ingersoll, the double-sided inserts are thinner and the larger grooves on the tool are designed to facilitate increased depth of cut
After several tests, Bauer reduced the feed and attempted to achieve a surface finishing accuracy of 25 microinches (20in / min at this time, with all other parameters remaining constant) .This change allowed the cycle to be extended to 39min , But still a 25% reduction over the previous tool life has also been improved, and now, a workshop tool used, the life expectancy of the previous eight tools used for a long time, which became McGill in the A standard parameter in the machining process, the challenge of tool breakage has been overcome today, and the company has adopted a flaw mode of side wear that provides additional protection for the machining process.
'The process time has been greatly improved by reducing downtime for tool maintenance,' says Bauer. 'We were able to run a full shift more than once using a set of knives and there was no risk of blade rupturing during that time . "He estimates that the re-assembly of the tool could save McGill a total of about $ 10,000 a year in cost.
In addition to the heat-hardening properties of Di-Pos Hexa tool materials, there are several key factors that can be used to explain their superior performance on the D-2. "First, the insert has both axial and radial forward taper , Cutting moves tend to cleave rather than shave, so this creates cutting forces and heat, "Johnson said.
Figure 4 This front and back view shows the comparison of raw and finished parts, after which the weight of the original part has been reduced by as much as half
The second factor is that the advanced coating on the blade surface reduces friction and provides thermal insulation to the blade substrate from the heat generated by the machining. "As the chip falls off the cutting area, The coating transferred the heat generated by the machining to the chips to cool the tools and workpieces, and statistics on hundreds of applications confirmed that the coatings typically increased blade performance by 35%, even when handled It's hard material, "Johnson said.
Di-Pos Hexa tools also include other features such as a thicker blade and a larger groove on the tool, which allows it to achieve a depth of cut of 0.230 in without causing chip plugging, Johnson said: "When handling heat- When hardened materials, such as D-2, especially pay attention to increase the depth of cut Whether you realize that only when the cutting edge reaches below the surface of the hardened material and into the softer material of the inner layer, what you are doing Operation can only be described as the mechanical processing of hard parts.
McGill is the first user to use the Di-Pos Hexa tool manufactured by Ingersoll Corporation, a company that is primarily engaged in tooling equipment, recently introduced the tool for shoulder milling and active slope dressing operations. Although the blade is double However, its cutting edge has both axial and radial forward taper.
To help maintain the shop floor, dealer Quality Tools and Abrasives installed a vending machine on site that housed various types of inserts used inside the company and was purchased from McGill's Ingersoll The company's blade occupies about 3/4.