根据麦肯锡公司最新的一项调研预测，至 2030 年，全球汽车产量的年增长率为百分之二。以差动传动装置为例，如何在保证达到高质量要求的同时，也满足日益增加的产量要求：无论使用何种驱动系统设计，该核心组件均必不可少。换言之，差速器壳体的产量将持续增加。同时，差速器外壳的加工要求也极其严格。埃马克集团在这个领域中已处于优势地位：这家专业制造商研发包括倒立式车削中心、工件输送系统解决方案和夹具在内的完整生产线，从而能为用户提供差速器外壳的高效加工整体交钥匙解决方案。
进行驱动：过弯时用于平衡两个车轮之间转速的车桥差速器总是不可或缺的。另一方面，工件种类繁多，并且全部需要高效可靠地进行生产。以差速器外壳为例：差速器外壳有内部为球形或半球形的封闭式壳体，也有配备盖子的“开放式”壳体，这些不同的形状会影响加工工序。但无论是哪种情况，都需要分为多道相互协调、依次执行的子工序进行加工。设计制造此类整体系统便是总部位于萨拉赫的埃马克集团这样的专业制造商的任务。“我们为各种差速器外壳的加工研发完整的解决方案。方案中所采用的工艺技术，包括倒立式车削中心、夹具和连线装置，均来自埃马克。客户可向埃马克中心联系人一对一提出所有要求，然后将整个项目规划工作外包给我们。我们可以为客户提供经过完美协调的整体式系统——节拍仅 95 秒、场地需求小、工艺可靠性高，”埃马克的模块化解决方案技术销售经理兼差速器外壳技术专家 Daniele Loporchio 解释说。
四道工序、节拍仅 95 秒即可达成目标
埃马克展示的差速器外壳制造系统以其简单而巧妙的设计令人印象深刻。为能实现这一节拍仅为 95 秒的完整加工工序，各机床无一例外地采用了埃马克的模块化解决方案，并与 TrackMotion 工件输送系统高效联接。
OP 10 / OP 20：车削差壳面一侧 / 法兰面一侧
差壳首先在两台 VL 4 车床上进行加工。此处将完成轴座和法兰的内部和外部加工。VL 机床配备具有 12 个刀位的动力刀具刀塔，还可实现十字轴孔钻削加工。
差速器外壳的剩余外部加工可在一台 VT 4 车床上通过一次装夹完成。由此可排除重复装夹定位带来的装夹误差。VT 4 配备两个刀塔，每个刀塔具有 11 个刀位。由此可实现 4 轴同时加工，从而缩短节拍。工件的平行上下料也确保缩短非加工时间。
后续加工在一台 VL 6立式车削中心上进行。在 OP 40 中，埃马克专为差速器外壳加工而设计的独特夹具（见图示）是一大亮点。在这道工序中对十字轴孔进行精铰加工，并用鹅颈刀对球顶先进行粗加工，然后再进行精加工——全部在一次装夹中完成。
此外，这套系统的连线也非常高效。基于埃马克的模块化和标准化机床平台：由于具有统一的传送高度、软件控制系统和上下料主轴，可以轻松地使用埃马克的 TrackMotion 工件输送系统来连接各台机床。配备可编程电动机械手的升降翻转滑台可在各台机床之间的轨道 (Track) 上来回穿梭，并将差速器外壳放置到输送带上。之后，由上下料工作主轴将工件送入和送出加工区——这是一个非加工时间极短的快速进程。还有很重要的一点，由于采用紧凑型的立式机床，整条生产线的占地面积非常小，可轻松访问及设置各个模块。
近年来，这种精简高效的生产方法越来越成功：在全球范围内，已有 60 至 70 条埃马克生产线、共约 250 台机床应用于差速器外壳的车削生产。原始设备制造商和一级供应商均信赖这种工艺技术。“我们提供从机床到夹具的整套交钥匙产品。所有组件都已完美协调匹配。我们所有的研发工作都以丰富的实践经验为基础，这些优势将在市场上得到认可，”Loporchio 总结说。
根据工件/工艺技术要求，在收到订单后约 6 个月，便可向客户交付一套完整的差速器生产线模块化解决方案。
Production system by EMAG:
High-performance solutions for differential cases
The worldwide production of motor vehicles is set to rise by about two percent every year until 2030, according to the estimates of a new McKinsey study. An excellent example of how to handle these rising production volumes despite stringent quality requirements can be found in the differential: This key component will remain indispensable whatever the propulsion system used by the vehicle. In other words, production volumes of differentials will continue to rise. At the same time, the machining required for parts like the differential case can be very demanding. The EMAG Group is well positioned in this environment: Its specialists develop complete production lines including vertical turning centers, automation solutions, and clamping devices. The user receives a turnkey, high-performance production solution for differential cases.
The differential case is still a constant focus of attention among production planners in the automotive industry. For one, it doesn't matter whether the vehicle is powered by a combustion engine, an electric motor, or a hybrid engine: They all require an axle differential that compensates the speed between the two wheels during turns. On top of that, there are different versions of the component that all need to be manufactured efficiently and reliably. Take the differential case, for example: There are closed cases with a spherical or hemispherical internal shape, and “open” cases with a lid. These shapes have an effect on the machining sequence. In all cases, however, a number of subprocesses are required which need to be carried out in a perfectly timed sequence cycle. Creating an overall system that can do this is a job for specialists—like the EMAG Group based in Salach, Germany. “We develop comprehensive solutions for machining different types of differential cases. EMAG supplies all the technology r equired, including vertical turning centers, clamping devices, and interlinking of machines. Customers discuss their requirements with a single point of contact and outsource the entire project planning to us. The result is a perfectly calibrated comprehensive system with short cycle times of only about 95 seconds, a small footprint, and high process reliability,” explains Daniele Loporchio, Technical Sales Manager Modular Solutions and technology expert for differential cases at EMAG.
ob done in four operations with a cycle time of only 95 seconds
What is striking about the manufacturing system for differential cases that EMAG is presenting is its simple and yet ingenious design. To implement such comprehensive machining within a cycle time of only about 95 seconds, the machines used are exclusively based on EMAG Modular Solutions building blocks that are interlinked with the TrackMotion automation system.
OP 10 / OP 20: TURNING OF THE CASE SIDE / FLANGE SIDE
The case is first machined on two VL 4 turning centers. This is where the internal and external machining of the shaft mounts and flanges is performed. Furthermore, the driven tool turret with 12 tool posts on the VL machines enables them to drill cross holes.
OP 30: TURNING OF THE OUTER DIAMETER
The remaining external machining of the differential case is performed with a single clamping operation on a VT 4 turning center. This eliminates the occurrence of positioning errors when changing the clamping position. The VT 4 has two tool turrets with 11 tool posts each, which enables 4-axis simultaneous machining and thus quick processes. Moreover, parallel loading and unloading of components ensures short idle times.
OP 40: FINE MACHINING AND FINISHING
Machining is then performed on a VL 6 pick-up turning center. In OP 40, the imposing clamping device catches the eye. It was specially developed by EMAG to machine differential cases (see image). In this operation, the bore holes are precision machined and the spherical calotte is first rough-machined on the inside with a special tool and then finished—all in a single clamping operation.
All that remains to be done now is final quality control. This is performed on an additional measuring system and thus guarantees that each differential case is of flawless quality.
The interlinking of the machines in this system is also especially effective. It is based on EMAG"s modular, standardized machine platform: With their uniform transfer height, software control, and pick-up spindle, the machines can easily be connected using EMAG's TrackMotion automation system. A lifting and flip-over carriage with a programmable electric gripper runs back and forth between the machines on a track and places the differential cases on a conveyor belt. The pick-up working spindle then transports the parts in and out of the machining area, in a rapid process with little non-productive time. Owing to the compact vertical machines, the overall line has a very small footprint, and the modules can be accessed easily for setup.
Successful in the marketplace
In recent years, this slim and efficient approach has enjoyed ever greater success: 60 to 70 EMAG production lines with a total of around 250 turning machines are already in use around the world in the production of differential cases. OEMs and tier 1 suppliers rely on this technology. “We offer the complete package, from machine to clamping device. All the components are perfectly matched. Also, all our development work is grounded in a lot of practical experience. These advantages are gaining recognition in the marketplace,” says Loporchio in conclusion.
A complete differential line based on the Modular Solutions building block can be delivered in only around 6 months after receipt of the customer"s order—depending on the component or the technological requirements