- Masterpiece in the world 2023/01/31 UP
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Masterpiece in the world #35
Special tool that largely reduces cycle time and eliminates chip trouble
- Tag
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- Peripherals
- Automotive
- Agricultural/construction machinery
- Accuracy improvement
- Chip disposal
- Setup time reduction
Generally, special tools seem expensive. However, creating custom tools optimal for workpieces may achieve significant reduction of machining time, eliminate chip trouble, and reduce work costs in total.
This article will describe case studies that had been solved out of a wide range of job requests.
Introduction cases of special tools (1) Company A “Hydraulic Valve Body (Cast Iron)”
〈Issue〉There many tools to be used and the cycle time is long
The hydraulic valve body is a hydraulic control mechanism that stores valves to switch oil passages and maintain pressure in the automatic transmission. Company A produces hydraulic valve bodies that are equipped on construction machinery and agricultural machinery as well as industrial vehicles such as forklifts and heavy-duty trucks. Hydraulic valve bodies applied to these industrial vehicles generally use cast iron materials, and are finished to achieve required precision and form through surface processing and hole processing by machine processing.
Of the parts that require hole processing, there may be cases that the spool hole that stores valves exceed the measurement of approximately Φ15 to 40 mm and a depth of (L/D) 10D. Therefore, deep hole drilling and high-precision processing are required. For this reason, in addition to excessive work hour consumption for tool changing, tool purchase and management costs were high since several tools are required to finish 1 hole. In addition to "cycle time reduction," our customers demanded items with features to eliminate these issues including "improvement of ring chip trouble," "high-precision and stable manufacturing," and "simplification of tool management".
〈After Introduction〉Through the application of special tools, reduced of the cycle time from 60 minutes to 5 minutes and aggregated the number of tools used from 7 to 3 tools
Based on demands from company A, the tools were aggregated from the conventionally required 7 tools to 3 tools [Φ22 core drill, Φ20 ring-free reamer, bore multi-row T-slot tool grooving ground]. Among the three, the grooving ground can process several grooves with 1 tool and spool hole processing was reduced from 7 processes to 3 processes (if processes up until the honing finish is excluded). The cycle time was largely reduced from 60 minutes to 5 minutes.
Furthermore, conventionally, ring shaped chips that occur on the exposed part of the oil groove during reamer machining had to be removed manually. To counter this issue, KYOCERA Corporation proposed their unique ring-free reamer. Chips are finely fragmented because of its unique tip structure, suppressing the occurrence of rings. Additionally, the structure makes it easier to machine chips that occur, minimizing the burden of removal work.
The machining accuracy of the ring-free reamer is satisfactory with a surface roughness under Rz3.2 μm and cylindricity under 0.01 mm (honing finish is the general tooling). The cutting noise is extremely quiet and scratches and cloudiness on the finished surface have been eliminated. Achieved a longer tool life of 3,000 to 5,000 holes/blade for both core drill and reamer (result based).
Customer feedback
- "In addition to cycle time reduction, greatly beneficial in terms of tool management since the number of used tool types can be reduced."
- "Through tool aggregation, ring shaped chips have been drastically reduced, minimizing the necessity to remove them even though the removal amount of the reamer itself has increased. We were astonished for its low machining noise and machining accuracy."
Introduction cases of special tools (2) Company B "Valve Body (Aluminum)"
〈Issue〉Occurrence of cone shaped chips, making the washing process necessary
Company B is a manufacturer of valve bodies which are components of automatic transmissions and CVTs for automobiles. This valve body is mainly composed of aluminum die-casting products and there has been a rise in cases in which they are machined with No. 30 taper compact machining centers in Japan. Aluminum chips, which are highly ductile, are highly elastic, and are required to be finely fragmented. Furthermore, due to the complex structure of aluminum valve bodies, the washing process was required since chips enter their concave parts.
The spool holes of valve bodies are aligned with varying types of holes of about Φ8 to 20 mm within their multi-staged structure, and special tools (rough machining drills as well as PCD brazing reamers for the finish machining) were conventionally applied based on the varying hole structures. Our customers had demanded products that "suppress cone shaped chips that occur from the protrusion point during rough machining for aluminum machining" and are "capable of both cycle time reduction and machining accuracy maintenance."
〈After Introduction〉Reduced cone shaped chips and minimized washing work
To respond to the demands of company B, cone shaped chips were fragmented by adopting a PCD twin-point drill for rough machining with a special cutting edge that has 2 drill tips. By adopting a multi-flute reamer (6 blade multi-blade PCD reamer), achieved a highly precise tool with a machining accuracy of H7, Rz3.2 μm, and circularity of 5 μm. Achieved a long tool life of over 100,000 holes/blade (result based).
Customer feedback
- "We are considering adopting the tool as an item that is capable of offering both high-precision and high efficiency machining."
- "Since there were no valid solutions for cone shaped chips that occur during rough machining, we are happy to have discovered a tool that improves the matter."
Merits of special tool introduction
In addition to establishing new lineups and introduction of machine tools, DMG MORI provides specification designs for dedicated tools based on machining environments and issues of customers with problems concerning their current tools.
Merit 1 / Cycle time reduction
Reduces cycle time by achieving aggregated tools through special tools.
- Depending on the shape of the hole, 3 to 4 tools were required for each hole. However, machining can now be completed in 2 steps.
- Since multiple areas can be simultaneously machined with 1 tool, the process requires only a small number of tools, and reduces the number tools need to be exchanged. Furthermore, new investments such as acquiring more magazine racks will become unnecessary.
- This establishes a formed tool for process aggregation and may also enable designs that require only 1 rough finish process.
- Enables highly efficient machining using multi-blade tools (finish: MultiFlute reamer).
Merit 2 / Improvement of machining accuracy
Improves machining accuracy by applying tools that are optimal for each machining process and tools that make full use of processing machinery performances.
- Achieved satisfactory circularity by accurately machining semi-finishing.
- Achieved satisfactory finished surface quality with the unique margin structure.
Merit 3 / Elimination of chip trouble
Prevents product failure by reducing the chip removal process and chip trouble.
* In addition to these cases, we are capable of proposing chip breaker application specifications through dedicated designs for customers in demand for improved chip processing.
Merit 4 / Improvement of compatibility
Capable of a high-precision hole tolerance design. Capable of handling demands for severe hole tolerance.
Merit 5 / Environmental conservation
Contributes to CO2 reduction through shortened machining time.
Proposing optimal solutions for DMG MORI machine tools
KYOCERA special tools have a high rigidity with a design that supports high-speed rotation. They demonstrate higher performances when combined with DMG MORI machine tools.
Production efficiency can be improved and costs can be cut since processes can be aggregated by using KYOCERA special tools. Furthermore, KYOCERA tools guarantees long tool lives and precision, and may be capable of securing stable product quality in the long-term compared to conventional tools if continuing to perform the same machining process for various items in small lots. Please feel free to contact us if you are considering to further improve productivity of your manufacturing line.
| KYOCERA Corporation |
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