Displacer Valve test rig.

One of my projects at Power Torque Engineering this easter was to design and build a test rig for the new displacer valves. They have been designed (the displacer valves) by another engineer at the company and they work fantastically, however they are assembled in house and this assembly may damage the seals or internal workings. As the valves are going to be put straight onto an engine they need to be purged of air and replaced with oil and then pressure tested up to 10 bar (whereas the engine will reach 7 bar maximum).

The valve also has to be able to be changed quickly to allow for a quick turn around, so no threaded elements.

What I was given was a clutch master cylinder, a displacer valve, some material and a catalogue of components, along with plenty of help from the engineers there as this is my first hydraulic project.

Fig 1. The complete rig, now attached to the bench with G clamps.

As you can see, aluminium profiles are now my favourite system for test rigs. A toggle clamp with a two nylon cones are used to provide the seal. The clamp can hold up to 2kN in the current configuration (as the clamping point can move) and has been taken past the maximum reading on the pressure gauge with no leaking or bursts.

Fig 2. Close up of the nylon cone.

The nylon cone is the standard 60deg cone with a 2mm hold through to the 3/8" BSPT to allow the oil to flow. There is also a M6 thread in the back to allow for adjustment in the oil drip tray.

Fig 3. The plug for the back of the clutch cylinder

Using the insert as supplied by Ford a metal replacement was then created with a 3/8" BSPT at the rear and two flats to help with tightening when attaching the 3/8" BSPT to 1/4" BSPP.

Fig 4. Handle Clamp for converting to the master cylinder.

The clamp was machined as one although is two parts, swivels perfectly and is threaded in one of the blocks and has a clearance hole in the other, allowing for plenty of clamping surface. Also allows the swivelling  around the clutch cylinder.

Fig 5. The ball valve and pressure gauge.

Using a P clip the female-T was clamped easily onto the profile. The same goes with the ball valve, the holes were opened up to clear a M6 bolt and then threaded into the aluminium profile, providing plenty of security and strength for turning it.

Unfortuantely as the clutch cylinder was designed for DOT fluid and not 15W40 (JCB engine oil) the one way valve has swollen and will no longer allow fluid to pass in either direction, rendering the jig useless. Another pump is being sourced and is to be attached to the jig which will solve all the problems. Seen as all the hard work and plumbing is done, the only thing to do is clamp the new pump on and then plumb it in.

And that is the end of my jigtastic easter.