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Concentric clamping elements

Hydraulic clamping elements for concentric clamping

for interior or exterior clamping

max. clamping force 2.8 up to 44 kN

Series Data sheet Technical data
H4.306
H4.306
 
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H4.306 Concentric clamping elements

 

2 and 3-point interior clamping

for interchangeable clamping jaws Ø 16 – 121 mm

double acting

max. operating pressure 250 bar

max. clamping force: 5 kN
stroke of clamping jaws: 10 mm
centring repeatability: 0,02 mm
positive air pressure connection
pneumatic stroke end control
optional contact control

H4.300
H4.300
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H4.300 Concentric positioning and clamping elements

 

with variable range of clamping

hydraulically operated

double acting

max. operating pressure 500 bar

piston/bolt Ø : 16 .. 32 mm
clamping force per pair of elements: 5 .. 20 kN
centre height: 52 .. 87 mm
clamping stroke: 6 .. 8 mm
repeatability: ±0.005 mm

H4.305
H4.305
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H4.305 Concentric positioning and clamping elements

 

2 and 3-point positioning

double acting

hydraulically operated

max. operating pressure 250 bar

clamping Ø: 25 .. 177 mm
bolt Ø: 12 .. 22 mm
clamping force at 100 bar: 4 .. 17 kN
clamping force at 250 bar: 10 .. 44 kN
position accuracy: 0,02 .. 0,03 mm
repeatability: 0,04 .. 0,06 mm

H4.307
H4.307
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H4.307 Parallel slide centring element

 

double acting

max. operating pressure 500 bar

clamping force / jaw: 2.8 .. 8.8 kN
stroke / jaw: 6 .. mm
piston Ø: 12 .. 20 mm
centering repeatability: ±0.02 mm

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figure 1: double clamping element for concentric interior clamping
 
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figure 2: double clamping element with prolonged connecting bar for exterior clamping
 
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figure 3: double clamping element with crossing for 4 elements
 
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figure 4: interior and exterior clamping
 
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figure 5: active principle of the concentric clamping element H4.300
 
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figure 6: 2-point concentric positioning and clamping element H4.305
 
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figure 7: 3-point concentric positioning and clamping element H4.305
 
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figure 8: cross section concentric positioning and clamping element H4.305
 
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figure 9: principle of concentric positioning and clamping
 
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figure 13: Concentric clamping elements H4.306
 
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figure 14: Special features of the concentric clamping elements H4.306






























 
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figure 10: principle of the double-acting parallel slide centring element H4.307
 

Concentric positioning and clamping elements H4.300 (figure 1-5)

Concentric positioning and clamping with two or three-jaw chucks on stationary fixtures is nothing new. In many applications, however, it is not possible to place the relatively large chuck bodies on the fixture. Often the smaller clamping strokes are an additional obstacle.

In our development, the individual parts can be connected to a two or multiple-element version. In the multiple-jaw version, each pair of jaws clamps independently of the remaining ones, thereby concentric clamping is obtained.

The opening can be determined by means of a connecting bar. The clamping strokes of the several sizes are designed such that manual or automatic loading and unloading can be effected also to clamp blanks with large tolerances. Also single-acting elements are available on request.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Concentric positioning and clamping elements H 4.305 (figure 6-9)

Workpieces with cast or machined bores, reliefs or break-outs, can be easily loaded to the fixture with the concentric positioning and clamping elements and concentrically clamped or positioned for machining. Overtolerance conditions can be avoided and clamping tasks can be completely solved by an ingenious combination of 2 and 3-point elements.

Various mounting and connecting possibilities extend the use for multiple applications. Different sizes and correspondingly adapted contact bolts allow exact adaptation to the required clamping diameter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Concentric clamping elements H4.306 (figure 13/14)

This hydraulically-operated concentric clamping element can be equipped with especially low clamping jaws to receive workpieces with interior centrings of low depth.
Suitable workpieces can directly rest on the clamping jaws so that additional support points are not required. With a combination of 2 and 3-point elements, workpieces with 2 centring holes can be exactly positioned.

Positive air pressure connection
The standard positive air pressure protection keeps the hole centre free of swarf, so that the base jaws can freely return.

Pneumatic stroke end control
The positive air pressure protection can also be used for the control of the unclamping position. The returning base jaws close in their end position the bore hole of the positive air pressure connection.

Optional contact control
In the version with contact control, pneumatic pressure is supplied to one of the base jaws, which is then transmitted into the clamping jaw.
In the crowned clamping surface there is a small bore hole. If a workpiece is clamped correctly, it closes the bore hole.

Application videos:

Parallel slide centring elements H 4.307 (figure 10)

This element is used in clamping systems in order to centre workpieces with small complicated contours and ribbing serving as a base for the definition of tolerances.
By a clever arrangement of the centre of rotation to the hydraulic piston the retaining force of a clamping jaw is three times higher than the clamping force. If only one clamping jaw acts at the workpiece, the clamping force is twice as large. This happens as long as the workpiece is moved to the centre.

 

Seal kits
for hydraulic elements

data sheet S0.001

Concentric positioning and clamping elements H4.300
- Contact bolts
- Dowel pins DIN 6325

see data sheet H4.300

Concentric positioning and clamping elements H4.305
- flange mounting
- mounting by segments
- mounting by ball nut

see data sheet H4.305

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figure 1: clamping unit to clamp bars



























 
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figure 2: concentric positioning and clamping of two housings
 
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figure 3: vertical machining centre with clamping fixture in plate design
 

Application videos:

Application example 1 (figure 1)
Concentric positioning and clamping elements H4.300
The flexible clamping unit is used to clamp bars which can be machined in every position, e.g. drilled, milled, threaded, etc. In conjunction with a pneumatic two-jaw chuck the rotary indexing table is used to determine the machining position of the workpiece.
The two-jaw chuck and the right-hand concentric clamping element keep the bars in the exact working position. The floating clamping element in the centre supports the bar. For this purpose it must work in a floating way, that means without centring function, what can be obtained by omitting the connecting bar. (Available on request)

Application example 2 (figure 2)
Parallel slide centring elements H4.307
The opposite figure shows a hydraulically-operated fixture for concentric positioning and clamping of two cast housings, whose interior surfaces are due to functional reasons have to be concentrically arranged to the machined holes.
The machining of the interior surfaces could be avoided thanks to the use of concentric clamping elements.

Application example 3 (figure 3)
Parallel slide centring elements H4.307
The clamping fixture in plate construction installed on a vertical machining centre with rotary indexing table and trunnion bearing.