single and double acting
with and without centring function, with pull-down clamping
The bore clamp is particularly suitable for centring and clamping of workpieces with smoothly machined bores with diameters from 16 to 46 mm and a support surface square to the hole axis. The bore clamp is a combination of a double-acting pull-type cylinder equipped with a segment clamping bushing, which is pulled by a tie rod over a fixed cone. Thereby the segment clamping bushing expands radially to the bore diameter of the workpiece to be clamped. By the simultaneous axial movement the workpiece is clamped onto the hardened support at the housing. The obtainable low-clamping force depends on the factor of friction within the bore and the operating pressure.
The bore clamp is particularly suited for clamping of workpieces with smooth bore holes from diameter 7.8 to 17.7 mm in the support surface.
The bore clamp is a double-acting pull-type cylinder. An exchangeable clamping bushing is fixed to the piston.
The 4 segments of the clamping bushing are radially expanded with spring force by a conic clamping bolt. Thus the expansion force is always the same and independent of the hydraulic clamping pressure. Both unclamping of the clamping bushing and pull-down clamping of the workpiece are controlled hydraulically.
Connecting the positive air pressure protection, the clamping bushing is protected against swarf and coolants. In the hardened support surface for the workpiece there is a bore hole for connection of a pneumatic seat check.
The patented bore clamp is particularly suitable for positioning and clamping of workpieces with bore holes from diameter 6.6 to 13.8 mm in the support face.
The workpiece is directly put onto the bore clamp, so that the remaining surfaces are free for machining on 5 sides. Due to its small and eccentric design the bore clamp can be placed very close to the workpiece contour.
The variants with centring and compensation can compensate side loads. According to the load additional clamping forces can be necessary, since the axial clamping force is relatively small.
In the body of the bore clamp a double-acting hydraulic cylinder is mounted. By screwing in the clamping screw the piston actuates via a dowel pin a drive pin that
is eccentrically arranged at the edge of the housing. The clamping ring is centred on a taper sleeve and hold by the head of the clamping screw.
The clamping screw is secured by means of a thread coating against loosening. Penetration of liquids and swarf is avoided by the connection of positive air pressure protection.
The hydraulically-operated bore clamp is particularly suitable for clamping in workpieces with smooth bore holes in the support surface ranging from 8 to 12 mm in diameter.
The workpiece is placed directly onto the hardened supports of the bore clamp and is not deformed during clamping. Since clamping is effected within the bore, the remaining surfaces are free for machining on 5 sides.
The double-acting hydraulic cylinder operates a tie bolt that is eccentrically arranged at the edge of the housing in which the clamping bolt is safely engaged.
This conical clamping bolt expands the hardened clamping bushing so that its points penetrate the bore surface in the workpiece with a positive fit (see “Clamping principle”).
Clamping bolt and clamping bushing can be exchanged very quickly after loosening the workpiece support. The bore clamp can remain on the fixture and no hydraulic oil escapes.
All functions can be monitored pneumatically. The use of the connection for positive air pressure protection prevents liquids and swarf from entering the clamping bushing.
B1.480 with a C-washer shows axial clamping of a workpiece in connection with a C-washer as per DIN 6371/6372. The C-washer (loose part) has to be attached for each clamping process.
When clamping with elastomer spring elements (see B1.480 with elastomer spring element) the workpiece has to be centered by a shoulder at the location flange, since only axial and radial clamping forces can be introduced by the elastomer spring element.
When using disks (B1.480 with clamping disks) centering is provided by the disks as the axial and radial forces are applied. The decision which clamping element has to be used, depends on the tolerance of the workpiece and the required axial retention forces.
As an option the hydraulic threaded-body clamping module with housing is available (Hydraulic threaded-body clamping module B1.480 with housing).
machining of an oil sump from 5 sides
machining of a plate from 5 sides on an indexing bridge
machining of an oil sump from 5 sides
Installation of hydraulic clamping modules in the base plate of a multiple clamping fixture.
Transmission of the clamping force is made by an elastomer spring element Ø 50 x Ø 17 x 32 mm high. The workpieces are centered by the shoulder at the flange. In such an arrangement for clamping neither a wrench is required nor a C-washer has to be handled.