Work supports

Hydraulic elements to support workpieces

single acting with and without spring return
double acting

Series  (19)

Items  (134)

  1. plunger Ø 32 mm, stroke 16 mm – off-position extended – contact by spring force – metallic wiper edge – pipe thread G1/4 at the side – max. 500 bar, as per data sheet B1.900
  2. plunger Ø 32 mm, stroke 16 mm – off-position extended – contact by spring force – metallic wiper edge – pipe thread G1/4 at the bottom – max. 500 bar, as per data sheet B1.900
  3. plunger Ø 40 mm, stroke 18 mm – off-position extended – contact by spring force – metallic wiper edge – pipe thread G1/4 at the side – max. 500 bar, as per data sheet B1.900
  4. plunger Ø 40 mm, stroke 18 mm – off-position extended – contact by spring force – metallic wiper edge – pipe thread G1/4 at the bottom – max. 500 bar, as per data sheet B1.900
  5. plunger Ø 40 mm, stroke 18 mm – extending hydraulically – contact by spring force – metallic wiper edge – pipe thread G1/4 – max. 500 bar, as per data sheet B1.911
  6. plunger Ø 40 mm, stroke 18 mm – extending hydraulically – contact by spring force – separate locking port – metallic wiper edge – pipe thread G1/4 – max. 500 bar, as per data sheet B1.911
  7. single acting with spring return – plunger Ø 40 mm, stroke 18 mm – off-position retracted – contact by spring force – metallic wiper edge – pipe thread G1/4 at the side – max. 500 bar, as per data sheet B1.910
  8. single acting with spring return – plunger Ø 40 mm, stroke 18 mm – off-position retracted – contact by spring force – metallic wiper edge – pipe thread G1/4 at the bottom – max. 500 bar, as per data sheet B1.910
  9. single acting with spring return – plunger Ø 32 mm, stroke 12 mm – extending hydraulically – contact by spring force – metallic wiper edge – pipe thread G1/4 at the side and – manifold mounting with O-ring sealing – max. 500 bar, as per data sheet B1.914
  10. single acting with spring return – plunger Ø 32 mm, stroke 12 mm – extending hydraulically – contact by spring force – metallic wiper edge – pipe thread G1/4 at the bottom – max. 500 bar, as per data sheet B1.914
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Description

Application

Hydraulic work supports are used to provide a self-adjusting rest for workpieces and avoid their vibration and deflection under machining loads.

Single or double acting

To reduce the dimensions and the expenses for the control, most of the work supports are single acting with spring return of the support plunger. Double-acting elements offer the advantage that the support plunger can be returned to the off-position within a precisely defined time.

 
hydraulic diagram: single/double-acting work supports

Types of operation

For the support plunger there are 3 types of operation:

Off-position extended

The support plunger is pushed in by the workpiece against the spring force.

off-position extended

Off-position retracted

The support plunger extends pneumatically and returns by spring force.

off-position retracted

Off-position retracted

The support plunger extends hydraulically with spring force and returns by spring force or hydraulically.

off-Position retracted

Contact force

The workpiece must not be deformed by the contact of the support plunger. Therefore the contact is made with spring force or pneumatically. Depending on the size, the spring forces are between 8 and 100 N.
The spring force is the smallest, when the distance between contact bolt and workpiece is the largest.
With pneumatic operation the contact force can be precisely adapted by a pneumatic pressure reducing valve. The pneumatic connection serves at the same time as connection for positive air pressure protection.

contact force

Mounting position

The work supports function in any mounting position.
The technical data are only valid for the vertical mounting position. Due to the low spring forces the weight of the support plunger and the contact bolt can influence the contact force and speed.

Wiper

All work supports are equipped with wipers for the support plunger. Some versions have a metallic wiper edge to protect the wiper against rough and hot swarf.

wiper

Minimum operating pressure

To bridge the clearance between support plunger and locking bush an oil pressure of 25 to 50 bar is required. The minimum operating pressure of 100 bar already guarantees remarkable holding forces.

minimum operating pressure

Maximum load force

Work supports can only compensate the maximum load force with the maximum operating pressure.
The admissible load forces with other pressures can be taken from the load force diagrams on the data sheets.

Overload

If the forces indicated in the load force diagram are exceeded by more than 10 %, the support plunger can yield.

Side loads

Work supports compensate only forces in the direction of the plunger axis.
If side loads will be introduced into the support plunger, the thin-walled locking bush deforms so that the exact position of the workpiece is no longer guaranteed.
That means that the side loads generated during machining have to be compensated by fixed workpiece supports or by horizontal stops.

side loads

Positive air pressure connection

The safest protection against penetration of liquids and particles is the connection of positive air pressure protection. This is possible for all work supports with vent port. 
The air pressure must not exceed 0.2 bar.

Position monitoring

Pneumatic position monitoring is possible for work supports as per data sheet B 1.930.

Elastic deformation

Work supports have such as other steel components an elastic behaviour, i.e. they yield in case of load. The below diagram shows the elastic deformation of a work support with load. The comparison with a threaded screw jack used for support shows better results for the work supports.

Elastic deformation
elastic deformation

Technology

Function with locking bush

In the body of the work support a thin-walled locking bush is integrated, which locks cylindrically around a movable support plunger when pressurising the element with hydraulic oil. This function requires a minimum operating pressure of 100 bar. 

After depressurising, the support plunger is again freely-movable.

function with locking bush

Self-locking work supports B1.930 with integrated pneumatic position monitoring

In the body of the work supports an additional locking piston is installed that locks a movable support plunger when pressurising the element. 

After depressurising, the support plunger remains locked.

For unlocking a second hydraulic port must be pressurised, i.e. this element can only be operated in the double-acting mode.

 

The positions "support plunger retracted" and "support plunger extended" can be monitored 

with the pneumatic position monitoring. The pneumatic ports are directly at the housing of the work supports.

self-locking work supports B1.930 with integrated pneumatic position monitoring

Material

Support plunger: stainless special steel, hardened

Locking bush: stainless high quality steel

Body: free-cutting steel, black-oxide

Interior parts: nitrocarburized or stainless

Seals: NBR or FKM

Sealing materials

NBR = nitrile-butadiene rubber trade name e.g. Perbunan operating temperature: -30 to +100 °C

FKM = fluoro rubber trade name e.g. VITON® operating temperature: -20 to +200 °C

Venting of the spring area

All work supports, where the support plunger contacts the workpiece by spring force, must be vented (exception B 1940). Especially when using coolants a venting port is imperative to avoid that the coolants will be sucked in into the interior of the work support. In the case of non-compliance troubles of functioning can occur.

Maximum flow rate

If the flow rate is too high, the oil pressure increases so quickly that the support plunger will be locked before contacting the workpiece. In the case of this malfunction the flow rate has to be throttled.

The admissible flow rate is indicated on the corresponding data sheet.

If several work supports are connected to one line, the admissible pump flow rate is the total of the individually admissible flow rates: 

V adm. pump ≤ n * V adm. support.

Throttle flow rate

If the pump flow rate is higher than the admissible flow rate for the work support, throttling has to be effected in the supply line.

throttle flow rate

Air bleeding

Air in the oil can considerably prolong the clamping time. Work supports require only a very small oil volume for their operation. Since the hydraulic oil in the connecting line is nearly not moved, careful 

bleeding is required. If bleeding screws are not available, in the case of drilled channels screw plugs should be provided at the highest and remotest point.

Attention! Bleed always at low pressure.

Contact bolts

Most of the work supports are delivered with a contact bolt in the support plunger.

This contact bolt has a dome-head and hardened contact surface.

Attention! Never use the work support without contact bolt, since penetrating dirt and liquids impede the function.

Special contact bolts

When using special contact bolts the following has to be considered:

1. The contact surface shall be hard and slightly dome-head so that it contacts safely the workpiece even in the case of uneven surfaces.

2. A plane contact surface can only be realised with a swivel contact bolt. However you have to reckon with a higher elastic compliance with load, since the swivel contact bolt will yield.

3. A contact bolt with point or ribbing has the disadvantage that the points press into the workpiece with load which results in a higher elasticity. In addition, there will be a form fit so that side loads will be introduced into the work support, which is not admissible. 

4. The threaded stem of special contact bolts must have the same length and interior contour as the original. On demand a drawing can be sent.

5. Special contact bolts should have a maximum weight of 100 grams to guarantee the springy contact and the return stroke of the support plunger. Please contact us for the use of heavier or longer contact bolts.

 

special contact bolts

Dimensioning of the load force of work supports

The admissible load force of work supports has always to be dimensioned so that the clamping force of the used

clamping elements and the static and dynamic machining forces can be safely compensated.

Adm. load force

- clamping force

- safety (reserve)

= possible machining force:

If the total of all occurring forces exceeds the admissible load force, the support plunger of the work support will be pushed back and the work support will be damaged.

Important note!

The admissible load forces as per the diagram are static. The machining forces can also generate vibrations which exceed by far the mean value. For this reason a corresponding safety factor has to be taken into account.

Clamping against work supports Control of the clamping sequence

The sequence – supporting and clamping – has to be controlled as a function of the pressure, e.g. by a sequence valve. If due to a too high flow rate a throttle valve is required, installation should be made as shown in the hydraulic circuit diagram.

clamping against work supports control of the clamping sequence

Dimension tolerances

If not otherwise indicated, the general tolerances as per DIN 7168 page 1+2 are valid for the connecting dimension.

PDF Data sheets

PDF

Work supports off-position extended – contact by spring force – single acting – max. operating pressure 500 bar

Catalogue sheet B1.900
PDF

Work supports extending hydraulically – contact by spring force – single acting with spring return – max. operating pressure 500 bar

Catalogue sheet B1.910
PDF

Work supports extending hydraulically – contact by spring force – double acting – max. operating pressure 500 bar

Catalogue sheet B1.911
PDF

Work supports extending hydraulically – contact by spring force – single acting with spring return – max. operating pressure 500 bar

Catalogue sheet B1.914
PDF

Work supports contact by spring force or air pressure – single acting with/without spring return – max. operating pressure 500 bar

Catalogue sheet B1.921
PDF

Work supports, self-locking with pneumatic position monitoring – double acting – 3 sizes – 2 types of function – max. operating pressure 500 bar

Catalogue sheet B1.930
PDF

Work supports threaded-body type – M30 x 1.5 – single acting – max. operating pressure 500 bar

Catalogue sheet B1.940
PDF

Work supports threaded-body type – M30 x 1.5 – with metallic wiper edge – 2 sizes – 3 types of function – single acting – max. operating pressure 500 bar

Catalogue sheet B1.9401
PDF

Work supports threaded-body type – M30 x 1.5 – with metallic wiper edge – 4 sizes – double acting – max. operating pressure 500 bar

Catalogue sheet B1.9402
PDF

Work supports threaded-body type – M26 x 1.5 – with metallic wiper edge – 3 types of function – single acting – max. operating pressure 350 bar

Catalogue sheet B1.9405
PDF

Work supports threaded-body type – M40 x 1.5 – single acting – max. operating pressure 500 bar

Catalogue sheet B1.942
PDF

Threaded-body work supports 3 function types – with metallic wiper edge – optional contact control – single acting – max. operating pressure 500 bar

Catalogue sheet B1.943
PDF

Threaded-body work supports with metallic wiper edge – optional contact control – double acting – max. operating pressure 500 bar

Catalogue sheet B1.944
PDF

Threaded-body work supports 4 sizes – with metallic wiper edge – single acting – max. operating pressure 70 bar

Catalogue sheet B1.9470
PDF

Threaded-body work supports with metallic wiper edge, – double acting – max. operating pressure 70 bar

Catalogue sheet B1.9471
PDF

Threaded-Body Work Supports with metallic wiper edge – shaft length 20 – 100 mm – single and double acting – max. operating pressure 70 bar

Catalogue sheet B1.9472
PDF

Work supports threaded-body type – with metallic wiper edge – 3 sizes – 3 types of function – single acting – max. operating pressure 500 bar

Catalogue sheet B1.9501
PDF

Work supports top flange type – with metallic wiper edge – 3 sizes, 
3 types of function – single acting – max. operating pressure 500 bar

Catalogue sheet B1.9503

Application example

Application video:

Case studies