WO2009149893A1

WO2009149893A1 - Clamping and/or braking device

Info

Publication number: WO2009149893A1
Application number: PCT/EP2009/004129
Authority: WO
Inventors: Bernd Rachor; Edmund Likus; Klaus Lang
Original assignee: Hema Maschinen Und Apparateschutz Gmbh
Priority date: 2008-06-09
Filing date: 2009-06-09
Publication date: 2009-12-17
Also published as: DE102008027388B4; DE102008027388A1

Abstract

In a clamping and/or braking module having a master piston (2), which is preloaded in the open state of the clamping and/or braking module and can be activated, and a slave piston which produces a clamping and/or braking action, wherein in the event of braking, the master piston (2) transmits a force to the slave piston by means of a hydraulic medium situated in a pressure chamber, it is the aim to enable boosting of the braking force, while maintaining a compact and simple design, in the simplest possible manner. For this purpose, the master piston, which is assigned a brake booster pressure chamber (10), is acted on with a brake booster pressure in the event of braking.

Description

description

Clamping and / or braking device

The invention relates to a clamping and / or braking module with a biased in the open state of the clamping and / or braking module, controllable master piston and a clamping and / or braking action triggering piston, the master piston in case of braking by means of a pressure chamber located hydraulic medium transmits a force to the slave piston.

Clamping and / or braking devices are used in various embodiments in various fields of application. Both in the precise fixing of tools or workpieces on a linear rail as well as the protection against accidental falling or sliding along such a rail linear clamping or braking systems are equally used. Furthermore, clamping or braking systems of similar design are also used in the emergency braking of rapidly rotating machine shafts or disc brakes.

For power transmission from an external control of the clamping and / or braking device to the element to be braked or clamped, a hydraulic system can be used in such devices, in which the control first acts on a master piston. Based on this, the braking or clamping force is transmitted via a hydraulic medium to a slave piston, which in turn can act on the output side, for example directly to the element to be braked or clamped. In the case of brake systems, a brake shoe is usually connected with respect to the friction to be taken into account and the like between the slave piston and the element to be braked. The slave piston thus triggers in both cases

BESTÄTKäUNOSKOPIE probably the brake as well as the clamping effect. Such a system is known for example from the document WO 2007/095909 A2.

In principle, a distinction is made between active clamping and braking systems in which the braking force is actively induced from outside in the event of braking and passive clamping or braking systems in which the clamping or braking system is closed in the idle state and can only be opened by the action of force , In this case, usually a compression spring is biased, which is released in the event of braking and thus transmits the stored force in the spring to the brake piston. Depending on the field of application and prescribed safety regulations, an active or passive clamping or braking system is therefore used. A disadvantage of existing clamping or braking systems is that the maximum achievable braking force in the passive clamping or braking system is limited by the spring and the maximum possible bias by them and in the active clamping or braking system by the externally supplied force. However, this may not be sufficient in cases where increased safety requirements are placed on the clamping or braking system.

The invention is therefore an object of the invention to provide a clamping or braking system of the type mentioned above, in the simplest way, an increase in the braking force is made possible at the same time compact and simple design.

This object is achieved by the master piston can be acted upon in the brake case with brake booster pressure.

The invention is based on the consideration that the achievable braking force, ie the force with which the slave piston is pressed against the material to be braked or clamped, depends directly on the thrust force of the master piston. The thrust of the master piston is determined in conventional passive clamping or brake systems primarily by the prestressed compression spring. These Fe However, the force is limited by the spring used or in particular by the dimensioning of the spring used. For a further compact design, therefore, the compression spring should be suitably supported in case of braking. For this purpose, in the case of braking the master piston pressure spring side with an additional pressurized medium, for example, compressed air or a liquid hydraulic medium acted upon. The additional application of the master piston with a brake booster pressure increases the braking force. As a result, a combined active-passive clamping or braking system with variable compressive force is achieved at the same time compact design.

For the application of the master piston with a brake booster pressure, a brake booster pressure chamber is assigned to the master piston in an advantageous embodiment. This brake booster pressure chamber has a brake booster connection, by means of which a pressure-carrying medium can be introduced into the brake booster pressure chamber for acting on the master piston in the event of braking from the outside and can be controlled. Depending on the safety regulations and the area of application, the pressurized medium can be compressed air or even a liquid hydraulic medium.

In order to enable optimum adaptation of the clamping and / or braking module to the system-related safety requirements and to adjust the braking force appropriately, the pressure chamber is filled in an advantageous embodiment with a liquid hydraulic medium. The filling of a plurality of pressure chambers from a plurality of clamping or braking modules takes place via a centering device. As a result, the respective slave pistons are held in an exact and symmetrical position, thus guaranteeing a constant amount of charge during the filling process with the liquid hydraulic medium, for example hydraulic oil. Excess hydraulic oil can be removed by blowing a bleeder screw in the lower pressure chamber area bubble-free to the outside. A uniform ventilation is thus guaranteed. In order to achieve a further increase in the braking force, the pressure chamber is advantageously formed in longitudinal section L-shaped. As a result of this deflection of the force to be transmitted from the master piston to the slave piston, it is possible with appropriate dimensioning of the cross-sectional areas to increase the force. In this case, in a particularly advantageous embodiment, the leg of the pressure chamber facing the master piston has a smaller cross section than the leg of the pressure chamber facing the slave piston. The resulting larger cross section of the slave piston compared to the master piston a further increase in the braking force is achieved. This increase is the greater, the greater the ratio of the cross-sectional areas of the slave piston to the master piston.

To further increase the braking force, in an advantageous embodiment, a plurality of clamping or braking modules are combined to form a clamping or braking system. As a result, a braking force adapted to the safety regulations can be achieved. For a symmetrical arrangement and thus also for a balanced braking force, for example in a linear clamping system, at least one clamping or braking module is positioned on each side of the linear guide rail.

In order to achieve the most uniform possible braking force with adjacent clamping or braking modules, at least some of the brake booster pressure chambers of at least some of the individual clamping or braking modules are connected to one another on the media side, so that an externally induced brake booster medium distributes uniformly to the individual modules and the braking force of the individual modules remains constant. This achieves uniform braking of several clamping or braking modules. To promote a compact and simple design, the individual clamping or braking modules are integrated in the clamping or braking system in an advantageous embodiment in a common housing.

The advantages achieved by the invention are, in particular, that a controllable increase in the braking force of the clamping or braking modules adapted to meet the safety regulations is achieved in the simplest way. It can on the one hand by a suitable choice of the cross section of Geberbzw. Slave piston, but on the other hand also by a specifically selected liquid hydraulic medium and in particular by the possible and adjustable from the outside and adjustable brake booster on the brake booster connection the required braking force can be achieved. At the same time, the reaction time or the speed within which the braking effect occurs is significantly shortened by the additional admission of the master piston with a brake booster pressure. Also, it is only possible by the additional brake booster pressure to realize a compact design with high braking force, otherwise usually in Passivklemm- or braking systems, an increase in braking force only by increasing the compression spring and thus an increase in the entire brake or clamp module possible is.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

1 shows a section through two clamping or braking modules with the corresponding terminals,

2 shows a clamping or braking module with encoder and slave piston,

Fig. 3 shows two clamping or braking modules on a linear guide rail, and 4 a clamping or braking system with several clamping or

Brake modules.

Identical parts are provided with the same reference numerals in all figures.

The clamping or braking module 1 according to FIG. 1 comprises a master piston 2. The master piston 2 adjoins, on the one hand, a clearance pressure chamber 4 and, on the other hand, a pressure spring 6 arranged on the opposite side from the clearance pressure chamber 4. The release pressure chamber 4 is connected to a release pressure port 8 the outside of a pressurized medium in the release pressure chamber 4 can be passed.

The clearance pressure chamber 4 serves to bias the master piston 2. For this purpose, the clearance pressure chamber 4 is filled with a pressure-carrying medium and generates an overpressure in the release pressure chamber 4. This pressure pushes the master piston against the spring force in the direction of the compression spring 6 and sets the compression spring 6 under tension. In the biased state of the master piston 2, the clamping or brake module 1 is opened or there is no braking action. In the case of braking, the pressure-conducting medium is led out of the release pressure chamber 4 via the release pressure connection 8 and the excess pressure in the release pressure chamber 4 is reduced in order to actuate the master piston 2. By the spring force of the compression spring 6, the master piston 2 is guided in its rest position and the braking action of the clamping or braking module 1 unfolds. Since the fastest possible entry of the braking effect is to be achieved for safety reasons, compressed air is used as the pressurized medium in the release pressure chamber 4. This allows a rapid venting of the release pressure chamber 4 and thus a quick spring back of the master piston 2 in the rest position. Depending on the possible applications of the clamping or braking module but also other pressure-bearing media in the Freistelldruck- camera 4 are conceivable. On the side of the master piston 2 opposite the clearance pressure chamber 4, the clamping or brake module 1 additionally comprises a brake booster pressure chamber 10. This brake booster pressure chamber 10 is likewise provided with a brake booster port 12, via which a pressurized medium can be admitted from the outside into the brake booster pressure chamber. The brake booster pressure chamber 10 and the brake booster port 12 are designed such that in the case of pressure drop in the release pressure chamber 4, so in case of braking, the brake booster pressure chamber 10 can be additionally filled with a pressurized medium. This pressurized medium is supplied via supply lines to the master piston and acts on this with an additional pressure. As a result, the master piston 2 not only experiences acceleration by the compression spring 6, but also acceleration by the overpressure of the pressurized medium occurring in the brake booster pressure chamber 10. This results in that the master piston 2 can be performed faster in its rest position and thus on the one hand the braking effect of the clamping or braking module can be achieved faster and on the other hand, the braking force is increased. This substantially increases the safety requirements for the clamping or brake module 1, since the braking effect can be optimized from the outside by a suitable choice of the pressure-carrying medium of the brake booster pressure chamber 10 and by a suitable choice of the filling speed. Advantageously, compressed air is used here as a pressurized medium, depending on the application, various print media are conceivable.

The planes of the cuts shown in FIG. 1 by the clamping or braking modules 1 are offset in perspective. In the embodiment according to FIG. 1, each pressure chamber 4, 10 is provided with a connection 8, 12 assigned to it.

In the illustration of the clamping or braking module 1 in FIG. 2, the transmission of the force from the master piston 2 to the slave piston 14 and thus to the linear guide rail 16 is illustrated. The master piston 2 adjoins again to a release pressure chamber 4, the bias of the compression spring. 6 serves. Furthermore, the clamping or brake module 1 contains a brake booster pressure chamber 10 located on the side of the master piston 2 facing away from the release pressure chamber 4. This brake booster pressure chamber again serves to cause the master piston 2 to brake in addition to the acceleration by the compression spring 6 also by the overpressure of an in accelerate the brake booster pressure chamber 10 insertable pressure medium. Both pressure chambers 4, 10 are each connected to a port, not shown.

The master piston 2 of the clamping or braking module 1 according to FIG. 2 has a T-shaped longitudinal section, wherein the lower region of the master piston dips into the pressure chamber 18 and seals this airtight to Freistelldruckkammer. The pressure chamber 18 of FIG. 2 is filled with a liquid hydraulic medium. In principle, however, other pressurized media are possible. The return of the master piston 2 from the prestressed position to the rest position in the event of a brake causes the lower portion of the master piston 2 deeper immersed in the pressure chamber 18. As a result, the liquid hydraulic medium is initially displaced and in turn pushes the slave piston 14 in the direction of the linear guide rail 16. The targeted dimensioning on the one hand, the cross-sectional area of the upper master piston and the cross-sectional area of the lower master piston and the cross-sectional area of the slave piston 14, a further increase in braking force is achieved ,

The pressure acting on the liquid hydraulic medium in the pressure chamber 18 from the lower region of the master piston 2 is already higher than the pressure resulting from the spring force on the upper region of the master piston 2. This pressure increase is proportional to the size ratio of the cross-sectional area of the upper master piston cross section that of the lower master piston cross-section. The increased pressure of the liquid hydraulic medium in the pressure chamber 18 is transmitted to the slave piston 14. Since, in the exemplary embodiment according to FIG. 2, this also has a larger cross-sectional area than the lower master piston cross-section, the resulting force is again increases in proportion to the ratio of cross-sectional areas. By varying the cross-sectional areas of the master piston 2 and the slave piston 14, the resulting braking force can thus be adapted to the needs or safety regulations.

For optimum alignment of the slave piston 14, the filling of the pressure chamber 18 via a centering device. In this case, the slave piston is fixed during the filling of the pressure chamber 18 with the liquid hydraulic medium in its desired position. Excess liquid hydraulic medium in the pressure chamber 18 can be removed via a vent screw 20 bubble-free to the outside. A uniform ventilation can be achieved with it. Bubble-free filling of the pressure chamber is important because air bubbles in the pressure chamber in the event of braking would trigger a compression of the pressure medium in the pressure chamber. This would significantly affect the braking effect.

The clamping or braking system 22 according to FIG. 3 comprises two clamping or braking modules 1. Both clamping or braking modules 1 are integrated in a common housing 24 and mounted symmetrically on each side of the linear guide rail 16. Each clamping or braking module 1 has one each accessible from the outside Freistelldruckanschluss 8 or Bremsverstärker- connection 12 to bias the compression spring 6, not shown, and to amplify the braking force accordingly. In the case of braking, the two slave pistons 14 are pressed in the direction of the linear guide rail 16, wherein in the embodiment of FIG. 3, the slave piston 14 itself are not pressed against the linear guide rail, but this is done via attached to the slave piston brake shoes 26. These can be inexpensively replaced when worn, without the slave piston 14 must be replaced in a complex, costly replacement process. The clamping or braking system 22 according to FIG. 4 comprises a plurality of clamping or braking modules 1, which are arranged symmetrically on both sides of a linear guide rail, not shown. In the embodiment of FIG. 4, eight clamping or braking modules are specified, but the number can be arbitrarily increased or decreased depending on the required braking or clamping effect or safety aspects. 4, the slave pistons 14 have an improvement in the braking effect via brake shoes 26. The clearance pressure chambers 4 and the brake booster pressure chambers 10 of the individual clamping or braking modules 1 on one side of the linear guide rail are connected to each other on the media side , This allows a uniform bias of the compression springs and a uniform brake gain via the brake booster terminal 12. This reduces the risk of possible tilting of the clamping or braking system 22 on the linear guide rail 16 by uneven braking effect.

Furthermore, a use of the clamping or braking module 1 can also be used for braking fast-rotating machine shafts or brake discs. The targeted use of the brake booster safety requirements can be easily met.

LIST OF REFERENCE NUMBERS

Clamping or brake module Master piston Excess pressure chamber Compression spring Release pressure connection Brake booster pressure chamber Brake booster connection Slave piston Linear guide rail Pressure chamber Bleed screw Clamping or braking system Housing Brake shoe

Claims

claims

1. clamping and / or braking module (1) with a in the open state of the clamping and / or brake module (1) biased, controllable master piston (2) and a clamping and / or braking action triggering slave piston (14), wherein the In the event of braking, the master piston (2) transmits a force to the slave piston (14) by means of a hydraulic medium in a pressure chamber (18), characterized in that the master piston (2) can be acted upon by an additional brake booster pressure in the event of braking.

2. clamping and / or braking module (1) according to claim 1, characterized in that the master piston (2) is associated with a brake booster pressure chamber (10).

3. clamping and / or braking module (1) according to claim 1 or 2, characterized in that in the pressure chamber (18) located hydraulic medium is a liquid.

4. clamping and / or braking module (1) one of claims 1 to 3, characterized in that the pressure chamber (18) is formed in longitudinal section L-shaped.

5. clamping and / or braking module (1) according to claim 4, characterized in that the the master piston (2) facing legs of the Druckkam- mer (18) has a smaller diameter than the slave piston (14) facing legs of the pressure chamber (18).

6. clamping and / or braking system (22) with a number of clamping and / or braking modules (1) according to one of claims 1 to 5.

7. clamping and / or braking system (22) according to claim 6, characterized in that at least some brake booster pressure chambers (10) of the clamping and / or braking modules (1) are interconnected on the media side.

8. clamping and / or braking system (22) according to claim 6 or 7, characterized in that the clamping and / or braking modules (1) in a common housing (24) are integrated.