August 2019 Design Notes

Clippard’s Cordis controls use the proven EVP and DVP lines of electronic proportional valves, allowing for steady, repeatable downstream pressure as demand or processes change.

Proportional pressurecontrols go digital

Clippard has recently launched what it is calling its most revolutionary product in years — the Cordis proportional pressure control. Meaning “of the heart” in Latin, Cordis is at the heart of all that is important at Clippard, said Rob Clippard, VP of Marketing.

“Everyone wants a smarter product these days and so taking our technology and wrapping around that intelligence feedback from pressure sensors — from flow sensors, and from other types of devices, an electronic pressure controller is certainly the next phase, the next revolution of our product line,” Clippard said. “By having control over the manufacture of the valve, we have a great deal of discretion in the design of the entire pressure control unit and that adds value to our customers. It not only gives us the ability to select specific to applications, but it improves the overall turnaround time for getting product into the hands of our customers.”

Clippard’s new Cordis controls use the proven EVP and DVP lines of electronic proportional valves, allowing for steady, repeatable downstream pressure as demand or processes change. The result is a precise linear pressure control within a closed-loop system with ultra-high resolution and repeatability.

The Cordis uses a microcontroller, integrated pressure sensor, and two Clippard proportional valves. The inlet valve is connected to the moderately regulated supply pressure and the exhaust valve is connected to a port that vents excess pressure to atmosphere. Once a command is increased, the inlet valve opens up to allow supply pressure to pass over the sensor element that provides an active feedback for this microcontroller to satisfy the set point in the process. If at any point the sensor detects a value higher than the set point, the exhaust valve will open to vent off the excess pressure to maintain a stable and accurate control pressure in the process.

The normally-closed valves offer flows from 2.7 to 65 lpm and a typical response time of < 20 msec. Accuracy is ±0.05% of full scale and resolution is ≤ 5 mV. They are rated for temperatures from 32° to 120° F.

The Cordis is adaptable to a variety of sensors that can close the loop around not only pressure, but vacuum or flow. It provides smooth linear control and offers integrated internal or external sensor feedback. In addition, it offers multiple flow configurations and can be used in static or dynamic applications with the same proportional regulation.

This electronic pressure control device takes a command signal and compares it to the output pressure of the unit, said Matt Larson, Product Manager.

“Our unit uses two proportional valves, one on the inlet, and one on the exhaust side to relieve any process pressure downstream. The software is proprietary to Clippard and is integrated into the controller to constantly compare the command signal to the output pressure of the units on the feedback side,” Larson said.

Clippard’s standard product range is 0 to 150 psi, and the valves can be rated for vacuum through positive pressure. As a result, these valves are highly customizable. Different models are meant for different applications, said Ernie Doering, COO. “An unhoused unit is intended to go into an OEM instrument. We also have a housed version of Cordis, which is intended to be a standalone unit,” Doering said.

Typical applications would be in the leak test industry where they might be testing low flow, and low-pressure applications in the life science industry for needs such as DNA sequencing or DNA testing for diabetes. These applications require low volume, low flow, and low pressure and require very stable and highresolution control.

“Through our software design that we’ve done in house, we’re able to make the unit very flexible for customer applications. These units are going to be used in those hard-to-do applications where low volume and high resolution is required,” Larson said. “What we’ve done in the past is with a straight analog unit; this unit would have to come back to the manufacturer and be preset based on the customer requirements. With the Cordis, the customer is actually allowed and able to log into the unit and adjust the settings directly at the machines based specifically on what they need the unit to do. We’re putting that decision in the customer’s hands.”

Clippard added, “Having a digitally based platform gives us unlimited flexibility in meeting the needs of our customers. It really puts us in a unique position to where we can develop this product around the customer’s needs. With the digital platform, we can do that quickly.”

Clippard | clippard.com

Cordis is available in both an unhoused unit for OEM instruments and a housed version which operates as a standalone unit.

Cordis is available in both an unhoused unit for OEM instruments and a housed version which operates as a standalone unit.

Intelligent hydraulics toolholder controlsreal-time cutting process

Vibrations, chatter marks, tool failure — what has so far robbed many a machine operator of sleep will soon be athing of the past: With the smart iTENDO hydraulic expansiontoolholder, SCHUNK and startup company TOOL IT present theworld’s first intelligent toolholder that monitors the machiningprocess directly at the tool, and allows real-time control of thecutting parameters.

The intelligent toolholders from SCHUNK were designed in cooperation with the Vienna University of Technology and TOOL IT GmbH, Vienna. They fully use the potential of integrated process monitoring directly where the chip is formed. SCHUNK calls this strategy “closest-to-the-part,” whereby the intelligence is integrated directly into the first wearfree element of the machine equipment that is closest to the workpiece. The smart tool is offered initially in combination with SCHUNK TENDO hydraulic expansion toolholders starting in 2019, allowing complete documentation of process stability, unmanned limit value monitoring, tool breakage detection, and realtime control of the speed of rotation and feed rate.

TENDO clamping technology is designed for demanding, universal precision machining and is suitable for all common shank types. It can be used for short or long, thick, slim and interfering contour optimized, for milling, tool grinding or turning machines. Intermediate sleeves make versatile clamping ranges possible. It features maximum run-out and repeat accuracy of < 0.003 mm.

“The iTENDO is a milestone in toolholder technology,” said Henrik A. Schunk, CEO. “For the first time, we combine the outstanding mechanical properties of our flagship TENDO with the possibilities of digital process monitoring.”

According to Friedrich Bleicher, the Managing Board Director of the Institute for Manufacturing Technology (IFT) at Vienna University of Technology and founder of TOOL IT, the intelligent toolholder makes a unique synergy possible. “Embedded systems technology combines the highest degree of process transparency with the potential of autonomous process control without users having to do without the quality and performance of proven precision toolholders,” said Bleicher.

During machining, the TENDO intelligent hydraulic toolholder permanently analyzes the machining process.

The toolholders with integrated process intelligence have the same interfering contours as conventional toolholder mountings. The use of cooling lubricant is still possible. Equipped with a sensor, battery, and transmitting unit, the intelligent system records the process directly in the tool, transmits the data wirelessly to a receiving unit in the machine room, and from there via cable to a control and evaluation unit, where the data is analyzed. An algorithm continuously determines the ideal parameters for process stability. Depending on the particular application, a web service can be used to define both the exact limits and corresponding reactions if they are exceeded. The entire process’s data remains within the closed control loop of the machine, ensuring the highest possible data security.

During machining, the intelligent toolholder permanently analyzes the machining process. If the process becomes unstable, it can either be stopped in real time and without the intervention of the operator, reduced to previously defined basic parameters, or adapted until the cut returns to a stable range. The system enables complete documentation and limit value monitoring as well as an improvement of the machining quality by automatically adjusting the cutting data during vibration. Moreover, the intelligent toolholders additionally enable an analysis of the tool condition as well as increase the metal removal rate. The system is extremely easy to retrofit without the need for modification or replacement of machine components. Because the algorithms run autonomously and the operator defines only exact limit and reactions, no expert assessment of the data is necessary. Instead, the system manages the process autonomously and in real time based on the specifications.

As a first step, SCHUNK will offer the intelligent toolholder mountings custom-tailored in the project business. Standardization is planned within the toolholder program as well. In addition to TENDO hydraulic expansion toolholders, further toolholders from the SCHUNK total tooling program will be equipped with intelligent sensor systems in the future. FPW

SCHUNK | schunk.com

The smart iTENDO enables realtime process monitoring and control directly in the tool. The geometry and performance data of the hydraulic toolholders remain unchanged even with sensors.

Simplified hydraulic pumps forlow-speed, high-torque market

Using mechanical energy produced by a machine’s engine, a hydraulic pump can move hydraulic fluid from the pump’s own reservoir to a connected hydraulic motor, converting the mechanical energy to hydraulic energy. The incoming fluid/energy triggers the hydraulic motor to begin rotation, which can be used to actuate a component outside the system, such as a wheel or axle. The power of hydraulics allows for machines to do more with less, such as traversing tough terrain or lifting heavy loads.

HP2 dual pumps can be direct mounted to a horizontal shaft engine, so there is no need for belts and pulleys. Like the HP1, the HP2 has an integrated filter, reservoir, and fan for cooling.

Why a piston pump?

In the world of hydraulics, the performance range of gear pumps and piston pumps overlap for low-speed, high-torque applications. This being the case, why would a consumer select one over the other? What kinds of advantages and disadvantages do piston pumps have compared to gear pumps?

Piston pumps provide robust and precise performance for myriad applications. Compared to a gear pump, a piston pump can operate at higher pressures with the same flow performance. Typically, gear pumps are rated for around 3,000 psi, but some models reach as high as 5,000 psi. On the other hand, piston pumps can be rated to as high as 30,000 psi.

Piston pumps can produce variable displacement; variable displacement is the act of adjusting flow during the usage of the pump while maintaining the same motor speed. Conversely, pumps that use fixed displacement can only operate at one flow specification. By using internal controllers, like springs and dampeners, a piston pump can change displacement while maintaining the same motor speed. Gear pumps require external valving to attain this effect, which can increase the cost of the overall unit.

While a piston pump provides greater pressure ratings and flow controls, a gear pump is a more cost-effective option. The gear pump’s interlocking gear design is simpler and easier to produce on a large scale, allowing for consumers to purchase the product at a lower cost. If an application requires a lower pressure rating and can operate using fixed displacement, a gear pump may be the proper solution.

The engineers at Parker Pump and Motor Division have developed the HP series of pumps, specifically designed for the low-speed, high torque (LSHT) applications. The HP series is the only line of the closed-loop, variable-displacement pumps, designed specifically for LSHT applications, with an integrated oil reservoir, filter, and cooling fan.

This model saves an engineer space within a design and reduces the number of components from 72 to 5. HP pumps are up to 20% more efficient than other pump and motor systems. They are compact and able to fit in small machine platforms where space is limited. They also easily connect to various Parker Torqmotors.

The HP series was designed to complement Parker transmission technology by addressing specific user needs. Those requirements included durability, compactness, integrated features to lessen leak points, and reduced OEM assembly time. HP1 single pumps incorporate a design with integrated filter, reservoir, and a low center of gravity pulley attachment point. HP2 dual pumps can be direct mounted to a horizontal shaft engine, so there is no need for belts and pulleys. Like the HP1, the HP2 has an integrated filter, reservoir and fan for cooling. FPW

Parker | parker.com/HPSeries

HP1 single pumps incorporate a design with integrated filter, reservoir, and a low center of gravity pulley attachment point.