This drilling machine for blocks has been developed for the drilling of Brake Block holes.
It can perform complete through holes and also holes with counter-bores dependent on the type of tool that is installed on the drilling units. The machine is developed to work on large batches and permits the guarantee of a high productivity output. The drilling machine has been designed to be connected to the Comec grinding lines.
The machine can be loaded either manually or automatically (for example when processing the blocks coming from a previous machine operation), in both cases, the blocks should be positioned on the loading area with the concavity facing down.
The feeding of the machine is carried out by means of a conveyor that will bring the blocks on the machine entrance and will be equipped with a system of guides to accommodate various sizes of blocks; the conveyor takes the blocks to the loading station (equipped with a checking sensor). When the block is in the loading station it is then brought into the machine by means of a pneumatic cylinder and blocked by a band during processing; during the unloading phase the block is extracted by a clamp which places it on a roller conveyor, ready to be transferred to the next operation.
Structure and features of the machine:
The machine is equipped with a PLC and an operator touch panel allowing customization of the cycle depending on the piece to be drilled. The setting prepared for the specific block type will be stored and will be possible to recall when processing the specific block batch again is required.
The main components of the machine are:
• Loading conveyor equipped with adjustable guides and pneumatic loading cylinder.
• Lining support in stainless steel with guide bushing tip (equipped with block clamping system and dust suction system). This part of the machine is dedicated to the specific part to be drilled.
• Drilling unit consisting of 10 units arranged in two rows of 5 each, the reciprocal position and angle of the drilling units can be manually adjusted.
• Drilling unit features:
a. Total stroke 80mm with fast speed approach motion function and working (drilling) speed motion function. The stroke origin and final positions are determined by a mechanical stop and additional electrical micro-switches
b. The drilling tool is activated by a pneumatic cylinder, the working stroke is controlled a hydraulic deceleration device.
c. Each drilling unit is connected via a flexible cable to a motion unit of 5.5 kW. Each motion unit controls 5 drilling units, thus the drilling power for each unit is 1.1 kW at 5000 rpm max at the drilling head
d. Dedicated design drilling tool according to the customer requirements
• Unloading system of the blocks, composed of a pneumatic manipulator which removes the already drilled lining from the working position to deposit it on a roller conveyor
• The base of the machine is provided with height adjustment to maintain a constant load zone to vary the radius strain (in the case in which we were bound by output bits of an other machine)
• Perimeter protections and guards, according to European safety level requirements
Brand of the commercial components installed in the machine
* Electrical components: Siemens
* Drilling units: SUHNER
* PLC and HMI: SIEMENS
* Pneumatic components: FESTO
Productivity and adjustment operations of the machine
The productivity of the machine can be slightly influenced by the type of composition of the material and the diameter of the holes that have to be performed. The maximum productivity of the drilling machine when making two rows of holes is about 600 pieces / hour.
Adjustment operations of the machine:
a) Remove the dedicated lining support (including the locking system) and replace it with the one to be used for the next lining part number to be drilled, this part is the reference for all parts of the machine since it accommodates the holes that will then be made on the lining.
b) Lock a sample piece (made of steel with dimensions identical to the piece to be realized) in the support and mount the tool on each drive required by the type of hole to be made.
c) Adjust each drilling unit adjusting the angle first and then the lower end stroke (in the case of a counter bored holes it will be necessary to get the drilling tool to the bottom of the counter bored holes. For this operation is necessary to start from the group the 5 drilling units and repeat the same operation with the second group after adjusting the distance between the two groups by means of a hand wheel.
d) Adjust the height of the machine to the level of the loading conveyor by means of the hand wheel dedicated (this adjustment allows to compensate the difference between the radii of the linings, while keeping constant the height of the loading level of the machine)
e) Adjust the guides of in feed conveyor
f) Select from the operator panel the units that will operate during drilling process
All these operations take about 2/3 hours.
Size linings that can be processed with the machine
The basic version of the drilling machine can be processed linings with 2 rows of holes, each row with a maximum of 5 holes each.
Another version of the machine that can drill more than 2 rows of holes has been developed, in this case the maximum productivity will be about 350 linings per hour.
The minimum distance achievable between the two rows is of 100 mm
The minimum obtainable angle between the holes of one row is of 9 deg, in relation to a lining with an internal diameter of 200 mm (the drilling tool comes out from the spindle 50mm)
The range of the lining internal diameter that can be processed in the drilling unit is from 170 mm to approx 250 mm.