阀体资格

At the time of this writing, two parties are discussing a fiscal cliff. Party one proposes to leave the political stalemate as is and just wait and see what happens after we go over the edge. That perspective has been compared to repainting a trillion square feet of rusted bridge (Figure 1）。

Figure 1: Bridge Collapse

The second party claims that there are alternatives to the stalemate and that the cliff can be avoided. Their view is to stop the traffic (i.e. programs and entitlements) until the bridge can be re-qualified so they can then decide if it should be repaired or replaced. Then a question was asked: How did we get to this point?

This situation struck me as a perfect parallel to valve body service. Politics aside, let’s review the evolution of valve body testing and the state of current qualification practices. Although traditional visual indicators such as the wiggle, deflection, flashlight and visual bore wear inspection are still useful, we’ll start this review with pressure and vacuum and before finishing up with valve body test stands.

目前有两种气压检测程序：未调节的气枪和校准的空气测试板。气枪测试源于离合器空气压力测试transmission手册适用于弗吉尼亚州lve body testing. A visual leak with an air test is caused by excessive valve-to-bore or end plug clearance. After air testing, the question becomes: What is normal or excessive leakage? The pass/fail decision requires experience to properly make, a downfall of this type of air test. Variables include the air supply, type of air tip, length of time to push out the fluid and noise level of the shop.

沿着阀体测试时间线移动到另一个十年，我们将固定装置添加到空中测试中隔离电路。实例包括4L60 / 80-E的修改的EPC螺线管，5R55E.,5R55W或者F5a等。现在，改变螺线管，并在组装单元的同时被指向EPC信号电路的空气。这些是具有成本效益的方法，并提供了钻孔的视觉指示（Figure 2A和Figure 2B）。

图2a： 5R55E.	图2B： 5R55W改性螺线管

The next refinement in qualifying a casting was the use of vacuum testing, a technique derived from valve guide/seat testing used in cylinder head remanufacturing. A minimal drop in vacuum occurs when this test is applied to valve-to-bore clearance. Vacuum is obviously the opposite of a pressure test. Where air pressure will push fluid and contaminants out of the bore, vacuum pumps will pull it into gauges and orifices. This means that – for best results when vacuum testing - it’s critically important the assembly is clean and dry. A routine calibration is performed to reduce contamination and also allow for variance in pump capacity. Unlike air testing, which hinges on a rebuilders’ personal experience, vacuum test gauges produce specific data that make for an easier diagnostic learning curve.

To perform a真空测试, the rebuilder seals a circuit with a plate or pad, moving between circuits to test various areas. Once clean, an entire casting can be checked for valve to bore tolerance. Other benefits include the ability to remove valves from the bore, check boost sleeve wear and the condition of solenoid seats, etc. (Figure 3）。

图3： Vacuum Test Assembly	图4： Air Test Plate

阀体空气测试板也使用空气压力，但精确调节压力和体积。在该测试中，组装阀体用螺栓固定在每个孔中具有多个进料口的板。空气流量计和计量仪（用于视觉或数字绑定到计算机的模拟）记录PSI降和流量增加。通常，测试并用作基线的新或可接受的组装。来自已知良好测量的方差越大，阀和孔之间的间隙越多。仪表和调节器用于所有应用，但每种类型的阀体都需要自己的测试板（Figure 4）。这种测试有一些大的优点。消除了预清洁和涉及紧固和记录计设备的劳动。还可以估计修复成本并在打开之前注明服务。

Figure 5: VBT Graph

接下来，我们来到现代液压阀门身体试验台或VBT的到来。硬件和软件进步一直迅速复制离合器 - 离合器和跳过移位。测试6-8速阀体或机电单元的关键是命令和记录，好像传输控制模块（TCM）运行它一样。这需要广泛的螺线管操纵和数据采集（Figure 5），特别是从排气到填充的多个螺线管的过渡或x模式。在老式VBT和ON / OFF阀体中，仅监测线尾离合器压力。操作员可以通过电缆控制节气门压力并使用随时间监控最小和最大压力。然而，较新的TCM，专注于时间和流量而不是压力（Figure 6）。The VBT of today can test the solenoid output and run a six-speed shift cycle in 2 minutes, without operator involvement.

Figure 6	Figure 7

A valve body test stand requires the addition of a specific plate just like air testing, but has the benefit of including the control program, harness and cabinetry. The payback for this equipment is realized in volume and quality assurance. A remanufacturer understands the VBT reduces R-R and rework from the dyno or vehicle.

这将我们带到当前变速箱状态，其中线性螺线管（Figure 7现在是离合器到离合器转换的框架。它们收到TCM输出并将其转换为可变压力。由于热，磨损和污染，线圈反应和压力降解，强制TCM调节或适应。但是，与联邦预算不同，TCM适应不是无限制的 - 它将设定一个代码，以阻止播出众所周知的悬崖 - 但是因为这些螺线管不再开/关，他们不能与空气等旧诊断方法有资格固定油压。类似于阀体或机电单元，它们需要在具有热，压力和循环时间的严重环境中进行测试。

鲍勃沃纳克is a Sonnax V.P. of Technical Development and a member of theTASC Force®(Technical Automotive Specialties Committee), a group of recognized industry technical specialists, transmission rebuilders and Sonnax Industries, Inc., technicians.