Omega has always been well known for its comprehensive range of no-bake moulding equipment and BZV coreshooters, but there has been the need for a low cost option to the jobbing machine range. With the forming of a joint venture in Australia with Warill Engineering, Omega had access to the Warill range of core making equipment.
The decision was made to manufacture the new range in the UK and build on the existing Warill platform, but with the additional challenge of making a low cost coreshooter with a very high specification.
The outcome was the CB series coreshooter.
By utilising Omega’s lean-manufacturing systems in Peterborough and taking the Warill design to the next level the company has been able to produce a machine with the following specification:
- Compact space saving design
- All hydraulic movement and clamping
- Suitable for vertical and horizontal coreboxes
- Slide fitted as standard
- Vertical hydraulic movement of the shoot head
- Vacuum Clamping for quick change of tooling (optional)
- Touch Screen control with up to 500 recipes storage
- Air-flow fluidising chamber for intricate cores
- Heated Gassing Plate
- Shoot pressure, purge pressure and liquid gas controlled electronically from the main touch-screen interface
- Linear transducers on all hydraulic cylinders for precise and repeatable movement
Omega built the first of the new range in 2013 and sold the first machine to Gedik in Turkey. Gedik was looking for a cost effective core making option but with a high specification so this was an ideal test for the first of the new range.
The introduction of electronically controlled sand shoot, gassing and purging pressures from the operator interface was a revolutionary departure from the conventional manually adjusted pressure regulators. It is now much easier and faster for the operator to make pressure adjustments from his work station. With a conventional manually adjusted pressure regulator fine adjustments are not carried out as often as they should be which leads to the same pressures being used for almost every core box – and the resultant poor core quality and wastage of gas due to leakages from an over pressurised core box!
The CB series coreshooter moves the shoot head up and down hydraulically instead of the conventional table lift –this means less hydraulic force is required and therefore longer life for the hydraulic system as well as lower hydraulic system costs.
The CB series also has the option of a fluidised shoot head which aerates the sand just prior to shooting, this leads to a much greater compaction with lower shoot pressures. This has the immediate effect of reduced core finning plus the added longer term effect of less sand erosion inside the corebox.
The gassing plate is also heated, so in the case of methyl formate where condensation is a major problem in cold ambient conditions, this feature is a must. There are also added benefits when using the C02 hardened phenolic resin process.
The integral gas generator has a separate heater for the liquid gas and the carrier/purge air. The liquid pump uses a positive displacement gear pump with variable speed controls (via the operator interface). The air flow through the heater is controlled by a proportional valve which is in turn controlled from the operator interface. The considered best practice for gassing requires an initial air/vapour pressure of approximately 0.1 to 0.4 Bar – measured at the corebox. The proportional valve is then ramped up to a value of typically 1 to 4 Bar during the purging part of the cycle. The operator can set the final purging pressure or absolute value via the operator Interface.
This data along with the relevant corebox gassing parameters is then stored as a recipe for that particular corebox.
A liquid calibration feature allows the amount of liquid gas to be easily checked as it leaves the pump. The pump output can be varied via a variable speed pump motor which is in turn controlled from the operator interface.
A major problem with jobbing and low series core production is the time and effort taken when carrying out a tooling change. Omega can now offer a vacuum clamping option to the CB series so that pattern change times can be drastically cut.
The CB series of coreshooter has a colour touchscreen interface with storage for up to 500 recipes. Each recipe consists of corebox identification, corebox left half and right half positions (useful when the shoot entry into the corebox is off-centre), number of shoots, gassing time/pump output/gassing pressure, purge time/pressure and finally whether slide or side clamps are to be included in the cycle or excluded. The interface also has auto/manual controls, real time status for all components as well as full fault diagnosis with alarms. All of these features can be password protected so that any changes can only be made by authorised personnel.
At the moment the CB range has three models – 10 litre, 30 litre and 60 litre capacity. It is planned to further extend this range as demand requires.
Mixed sand is provided separately via either continuous mixer or high speed batch mixer with multiple recipes and auto fill facility.