Camcon IVA for Combustion Development
The Camcon IVA system is under development for volume production in mainstream passenger car engines – however, it also provides a superb combustion research tool for the many companies who use dedicated single cylinder engines for this purpose. Camcon is making available single cylinder IVA valvetrains for this purpose.
IVA consists of a unique rotary electro-magnetic actuator driving a desmodromic mechanical linkage under high-speed closed-loop control. Every valve is supplied with its own actuator and is controlled individually – hence each valve can perform different events and, as there is no mechanical link to the crank, even multiple events within a single 720 degree cycle. The actuator angular velocity is not constant and in fact, varies considerably during each event. In fact, the actuator will normally “park” between events. It is the high-precision feedback control of actuator angular position and velocity that permits the following capabilities – unprecedented in a system that is also a technically and commercially realistic option for production engines:
- Valve timing is infinitely variable and constrained only by valve:piston proximity
- Valve period is infinitely variable down to a minimum - typically selected as ~6.5ms for full lift, shorter periods can be achieved for low lift values.
- Valve lift is infinitely variable between zero and maximum lift (defined by the cam profile)
- A wide variety of complex lift curve shapes are already available and further options can be designed on request
System diagnostics are built into the control system and linear valve position transducers are also built in for the single cylinder applications.
Using IVA for R&D
At the simplest level, IVA can be used to mimic the valve events provided by any conventional valve train system including the majority of variable systems – phasers, cam switching arrangements, oscillating cam systems, 3D cams – all can be modelled faithfully. Only the latest, hydro-mechanical systems cannot always be accurately modelled by IVA – and that is because they show such high lift curve vibration amplitudes under many conditions. This means that different cam profiles, different timings can be tested without the need for any engine rebuild – in fact, a previously unimaginably thorough “profile characterisation sweep” can be completed without even stopping the engine! At the other extreme IVA can be used to facilitate the most advanced combustion research: 2 to 4 stroke switching, radical in-cylinder charge motion manipulation, Miller cycle switching, HCCI, advanced EGR and pretty much anything else you have in mind.
The Single Cylinder IVA Offering
Camcon can provide the entire IVA and cylinder head system:
1) IVA actuators and mechanism either:
a. with an adaptor plate to fit your head, or
b. with a modified version of your head to suit the IVA actuators
2) Inlet and exhaust valves, retainers etc to suit
3) Suitable covers and connector arrangements for:
4) Remote power electronics complete with wiring loom
5) Remote Control electronics complete with wiring looms
6) Control software for the IVA system pre-loaded onto a dedicated laptop
7) Either (depending upon the test facility):
a. Interface software for the engine and test bed control and data recording systems
b. Assistance in writing the required software
8) Standard instrumentation to support both diagnostics and system health monitoring plus system performance monitoring (for each valve)
9) Additional instrumentation or provision for such instrumentation as required by the client
10) Installation and commissioning of the system at your site
11) Training your Technicians and Engineers in system operation and maintenance
12) Documentation in the form of User Manuals etc
13) A standard kit of spares and special tools (if required) or an enhanced set, by agreement
14) Full time support during the first 5 days of testing for training and familiarisation
15) Ongoing telephone support and on-site support (the latter at extra cost)
Should the client require it:
1) Camcon can design and supply additional cylinder heads/valves etc to allow the study of valve sizing and symmetry, different port arrangements etc.
2) In the event that the installation is the first for this particular bore/stroke/chamber combination on an existing single cylinder installation. Camcon can:
a. Liaise with the engine supplier to procure the necessary modified components, such as crankshaft, liner, con-rod etc and,
b) given the required port, chamber and water jacket data design and procure the entire cylinder head.
Complete Engine Supply:
In the event that the client wanted a complete single cylinder engine incorporating the IVA system and given appropriate port, chamber and other necessary input data, Camcon can work with a partner to supply the entire single cylinder engine.