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Hengst Filtration, a manufacturer of car and truck filters, relies on LiCON solutions due to productive advantages and environmental considerations, the company reported.

For Hengst Filtration, sustainability plays an important role. As a manufacturer of filtration solutions, this company not only produces parts that protect the environment and health, but also values ecological sustainability. In order to achieve this, Hengst is constantly looking for new solutions.

A recent application consisted of machining new die cast car and truck filter housings. Hengst Filtration invested in two automated machining cells built by LiCON. LiCON provides efficient solutions ranging from individual machines to fully automated production lines. At the heart of the automated LiCON production cell at Hengst Filtration are five LiFLEX II 766 twin-spindle machines, with fixtures and robots using grippers from LiCON's own design, and delivered production-ready to the facility.

Twin-Spindle Machines Have Competitive Advantages

In a larger cell, Hengst Filtration produces truck filters on three of the five LiFLEX twin-spindle machines. The other two LiFLEX twin-spindle machines produce car filters for a premium customer. With the decision to go with the LiCON twin-spindle machines, Hengst said they are experiencing economical gains and improved sustainability.

The installed twin-spindle machines provide the same output as single-spindle machines, but require 40% less floorspace. Therefore, the productivity per square meter is significantly improved. This was just one reason for the investment in LiCON twin-spindle machines.

Complete Machining in One Clamping

In the production line, Hengst Filtration had primarily used 4-axis single-spindle machines. For machining of five sides of the parts, at least two clampings were needed. With the new LiCON 5-axis machines, the parts can be completely machined in one clamping. This avoids re-clamping errors.

"For easy scalability, it is important that the workpieces are completely machined in one machine. Based on this, every additional machine will expand capacity. With the LiCON machining centers, this succeeded not only with the car filter housings, but also with the truck filter housings," said Project Leader Hans-Joachim Daum, Industrial Engineer at Hengst Filtration.

Nils Baumgartner, Key Account Manager at LiCON, said: "The cubic working envelope of the machining centers is designed with window fixtures in mind, so that 5-sided machining is possible. Hengst Filtration really desired that the ramp-up time is optimized, so the customer initially purchased one machine per part type."

MQL Replaces Coolant, Saves Energy

Typically, emulsion had been used as the lubrication method. However, in this case, Minimum Quantity Lubrication (MQL) was installed. A tool-specific oil mist mixture is transported to the cutting edge through cooling channels in the tool. During process development, the tool- and process-specific dosage parameters can be optimized and saved in the NC program. This means the machined parts are quasi-dry when they are removed from the machining center. The previous contamination of machine and the environment using coolant is avoided. The circulation of coolant via pumps and drive motors is also eliminated, which results in significant energy savings.

"A LiFLEX twin-spindle machine requires approximately 15 kW for MQL," said a company spokesperson. "In comparison to using coolant in machining centers, there are savings in electrical energy of at least 10 kWh per machining center. Over a year's time of 5,000 operating hours, there are savings of 50,000 kWh per machining center and 250,000 kWh for all five machining centers."

Similar Technology for Different Workpieces

At Hengst Filtration, two distinctly different size parts are machined using the same technology. On this basis, the machining of a large part and a small part on the same size machine was selected. However, they are distinctly different in the loading concept. In this case, the modular LiCON concept is of benefit.

The LiFLEX II 766 can be loaded three ways: direct load of the A-axis, double trunnion concept with two A axes or a pallet changer. For machining of the large parts with their commensurate longer machining cycles, the LiFLEX II 766 i DL B2 direct load was chosen. For load and unload of the parts, the machine is idle. However, this operation is so small relative to the cycle time that a second set of clamping devices for loading parallel to the main time would not be worthwhile. Additionally, the added effort of monitoring part quality is reduced by 50%.

For the smaller product used in cars, there is a completely different scenario. Marco Gerhard, Industrial Engineer at Hengst Filtration, explained his project as follows: "Due to the smaller cubic size of the car housings, the cycle time is significantly shorter than of the truck filter housings, so unloading/loading simultaneous to machining is the more economical solution of the three variations. Therefore, the pallet changer version machining center was installed. In this machine, it is even possible to mount two fixtures per spindle side. Therefore, two filter housings are machined per spindle, resulting in four completed parts per cycle. This improved the net cycle time per part by 15%."

Automation Properly Configured and Still Flexible

For machining of the large parts, three machining centers were installed. These were loaded via a robot mounted on a gantry, so that the parts would be loaded/unloaded from above. The LiCON-designed gripper consisted of four grippers so two finished parts would be unloaded, and therefore, two raw parts could be loaded by the robot in the same position. This ensures that the raw parts will be targeted properly in the fixtures.

The machining of the smaller parts consists of two machining centers opposed to each other, with one robot being able to service both machines. In both production cells, the raw parts are manually loaded onto a raw part conveyor. The buffer is large enough to allow for unattended operation during operator lunch breaks.

"Flexibility is important. On that basis, we also wanted access to the machines for manual loading. This allows us to process smaller lots of older designs on one of the three twin-spindle machines. This makes the gantry robot a good concept," said Production Manager Michael Cedrola.

Industry 4.0

Production systems with a high level of automation, as described here, allow for transparent data management. All the parameters of this project can be observed per part type. Countless relevant data is transferred from the machining centers to a central data storage.

In addition to this, other sensor systems, such as drill breakage monitoring as well as machining quality (as a function of vibrations), can be analyzed for further service requirements.

Single Source Integrated Solutions

Alf Bönisch, Team Leader of Industrial Engineering at Hengst Filtration, said that it is important that extensive projects like this should have as few points of contact as possible to ensure success: "LiCON supplies the entire installation as a turn-key supplier, including fixtures and automation. Therefore, responsibility is with one source."

Bönisch continued: "The robot hand is very complex. It has four grippers for holding two raw parts and two finished parts. For an effective interface to both fixtures, it was beneficial that fixture and robot grippers were developed and built by the same supplier. To minimize the process development time, LiCON simulated the entire process virtually and qualified the system using simulation programs. This saved valuable time."

Authored by Nils Baumgartner

For more information contact:

Licon mt LP

2135 Bishop Circle-East

Unit 1

Dexter, MI 48130

734-426-2240

info@licon.com