| Erlmann
Inside Radius Grinder Type IRG for Truck Blocks The machine is designed to accurately grind the inside radius of brake blocks to true radii according to OEM-specification and based on ROWLAND design. The machine is run by one operator who stacks blocks in a vertical magazine. Ground blocks exit (optional to a stack device in front of the operator). Grinding of up to 900 blocks per hour can be achieved. The machine uses a grinding belt running over a contact roller to produce the inside radius of tapered or parallel truck brake blocks. The contact roller has to be changed to suit the inside radius of the brake block to be ground. The machine is designed so that a minimum of material is removed from the internal radius of the block. The amount removed is the minimum to give a fully cleaned up ground surface. A timer is provided to determine the time the brake block is in contact with the grinding belt. The machine quoted is fitted with the automatic loading and unloading system so that the operator loads batches of blocks and the unloading operation is fully automatic. Semi-Automatic Loading of Brake Blocks Brake blocks are stacked in a vertical magazine, which holds an average of 14 blocks, by an operator. The magazine is adjustable to suit different arc lengths of blocks. A pusher blade slices the bottom block onto the pneumatic horizontal slide feed carriage. The carriage slides the block forward to a position under the contact roller and the abrasive belt. Grinding of blocks A vertical pneumatically operated fixture lifts the block from the input carriage and presses the block against the grinding belt. This unit has two separate assemblies. The bottom half is the lift table and the top half is the actual component location. A double rod air cylinder raises the lift table. Mounted on the rod top is a swivel device that supports a table to which the fixtures are attached. The amount of float of the tabletop is limited by jackscrews. The component location plate is adjustable for width and curvature. The brake shoe is supported on two bars. An adjustable blade at the side of the shoe takes the radial grinding thrust. The block is held against the roller and belt for a set period of time determined by an adjustable timer. This governs the level of stock removal. A 22 kW motor mounted on a rigid precision grinding spindle drives the grinding head. The main roller is interchangeable to suit the internal radius being ground. Above this roller is mounted a pneumatically tensioned idler pulley with a remote tracking system outside the guard. A 3,5 meter grinding belt will have a cutting speed of 30 m/sec. on a 450 mm diameter roller and a nominal width of 250 mm. Mounted around the belt is a guard fitted with dust extraction nozzles. After grinding the fixture retracts, leaving the ground block on the carriage. The fixture spindle runs on AC bearings at the top and a precision ball bearing at the bottom, rotation of the spindle is controlled by Digital Servo Motor with position feedback used to control the position of the grinding head. Blocks are located on circular fixtures which are matched to suit the inside radius of the linings to be ground. The fixtures are quick to change and locate on a precision parallel keyed spindle. Each fixture can grind both parallel and taper linings by selecting the appropriate program from the control. Stacking of Brake Blocks after Grinding After grinding the block is ejected onto short exit rails at the rear of the machine. A ground brake block reaching the end of the exit rails can be taken away by an operator. Optional (see price table) a conveyor return system transfers the ground blocks back to the front of the machine (saves one operator). Electrical Equipment The machine is controlled by a standard contactor control with industrial quality push buttons. The unit is mounted at the front of the machine and close to the operator. A master stop (emergency stop) button is fitted with a large mushroom head. The wheel access door is fitted with an interlock switch to prevent start up if left open and has a timer to ensure that the wheel has stopped before the door can be opened. Control and electrical enclosure is supplied for local supply 400 VAC, 50 Hz. Dust Guarding The machine is supplied with a full set of dust guards and extraction nozzles, ready for connection to customer's centralized dust extraction system. Technical Data» |
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