EP3580463B1 - Device having a piston, a cylinder and at least one inner tube and at least one outer tube - Google Patents

Description

The invention relates to a device with at least one inner tube and at least one outer tube, with the inner tube being mounted inside the outer tube, with at least one cylinder head, with at least one piston rod bearing and at least one sleeve.

In the case of cylinder-piston devices manufactured according to the prior art, it is known, for example, to press in two oversized end pieces at the end regions of a cylinder tube in order to close off the cylinder. In this way, an interference fit can be provided and the cylinder tube can be terminated as desired.

It is also known from the prior art either to glue end pieces into a cylinder tube or, conversely, to glue a cylinder tube into end pieces.

Furthermore, solutions are known in which end pieces welded with spikes are also wrapped into a cylinder tube during the manufacturing process of the latter. Designs are also known in which corrugated end pieces are wrapped with the cylinder tube during the manufacturing process of the latter.

In other solutions known from the prior art, a notched ring is wrapped together with the cylinder tube during the manufacturing process of the cylinder tube. Ring elements are inserted into the notch of the ring and clamped with a two-part end piece.

According to the so-called Darmstadt container design, it is also known to press a fiber-plastic composite tube drawn in at the ends into the conical receptacle of end pieces and to close it from the inside with an inwardly curved bottom to produce the cylinder tube.

Another known device is from WO 2014/153587 A1 known.

Disadvantages of the devices mentioned are the laborious manufacture and/or assembly required for their manufacture and the use of complex and correspondingly expensive individual components.

Against this background, it is the object of the invention to provide a device which can be produced particularly easily and which is better suited to buckling and/or bending forces occurring when the device is used or loaded, as well as by the pressure fluid on the cylinder-piston Device absorb compressive forces acting.

According to the invention, this object is achieved by a device having the features of claim 1 . Advantageous configurations are the subject matter of the dependent claims. Accordingly, a device with at least one inner tube and at least one outer tube is provided, with the inner tube being mounted inside the outer tube. the The device also has at least one cylinder head, at least one piston rod bearing and at least one sleeve.

The piston may include a corresponding piston head. The sleeve is designed to secure the outer tube on the piston rod bearing or on the cylinder head. As an alternative or in addition, means for a cohesive bond between the components mentioned can be provided in the coupling area defined in this way. The coupling can therefore be chosen in almost any way and also be combined. The boot attaches a slotted end portion of the outer tube to the cylinder head or to the piston rod bearing.

The sleeve can be at least partially concave in the area in which it bears against the slotted end area.

The terms cylinder head, piston rod bearing and end portions are to be interpreted broadly and may refer to features that are functionally similar to the features described. The cylinder head and/or the piston rod bearing can therefore refer to components that outwardly delimit or close off a cylinder-piston device in the axial direction. The slotted end areas can mean axially outer areas of the outer tube which do not have a planar outer surface, but instead comprise, for example, regularly or irregularly arranged recesses.

Due to the inventively designed coupling mechanism between the pipes and the cylinder head or the piston rod bearing, the use tube blanks that are particularly easy to produce for the production of the inner tube and/or the outer tube. This in turn requires a particularly flexible production of devices according to the invention with different Dimensions from a variable modular system of the components required for this.

Due to the simpler configuration of the device, continuous production of the semi-finished products required for assembling the device is also possible.

In a preferred embodiment, it is conceivable that the inner tube and/or the outer tube and/or the sleeve are made of a fiber-reinforced plastic and/or of a metal. It is therefore also conceivable that at least some of the components mentioned are made of a fiber-reinforced plastic, while another part of the components mentioned is made of metal. Combined components are also conceivable, in which both a metal or several metals and fiber-reinforced plastics or a fiber-reinforced plastic are used. The use of a fiber-reinforced plastic or fiber-reinforced plastics makes it possible to manufacture advantageously lighter devices.

According to the invention, the inner tube and the outer tube are closed by the cylinder head and the piston rod bearing.

In particular, this means closing off the respective cylinder tube or cylinder tubes on its or their circular top or bottom sides. The axially outer regions of the inner tube and/or the outer tube can thus be closed with an in particular at least partially circular or ring-shaped surface by means of the components mentioned. The term cylinder tube can refer to one of the two tubes, inner tube or outer tube, or also include both tubes.

According to the cuff of pressed onto the tongues of the outer tube.

The tongues of the outer tube can mean configurations or sections in the axial end areas of the outer tube be formed by the slotted design of the end areas as tongue-shaped, strap-shaped or similar sections of the outer tube and extend in particular in the axial direction outwards away from the rest of the structure of the outer tube. In this case, the sleeve can be arranged at least partially further outward in the radial direction than the tongues. A radially inner portion of the sleeve may be in direct or indirect contact with a radially outer portion of the tongues. An indirect contact means in particular a contact of the respective sections, in which an adhesive is additionally provided between the tongues and the sleeve.

The tongues can be pressed or bent against other components of the device in a particularly simple manner by the cuffs, and the coupling of the components mentioned can be effected in a particularly simple manner as a result.

In a particularly preferred embodiment, it is conceivable that adhesive is provided in the area of the tongues. The adhesive can improve the coupling between the components mentioned and also exert a sealing effect for sealing the cylinder-piston device in the respective area.

In a further preferred embodiment, it is conceivable for a pressure-resistant filler, in particular made of plastic, wood and/or metal, to be provided between the inner tube and the outer tube. The pressure-stable filler can enable better power transmission between the inner tube and the outer tube and thus reduce the pressure load on the inner tube, for example. The stability of the device with regard to loads other than the pressure load can also be improved by means of the filler. In particular, the stability of the device with regard to buckling and/or bending loads can be increased in this way.

In a further preferred embodiment, it is also conceivable that the inner tube concentric to the outer tube is stored. According to the invention it is provided that the inner tube is shorter than the outer tube. The difference in length between the tubes can essentially correspond to the axial extension of two sleeves. A length difference is conceivable here, which corresponds, for example, to more than 50% of the added axial extent of the two cuffs and in particular to more than 80% of the added axial extent of the two cuffs.

In a further preferred embodiment it is conceivable that the outer tube comprises two slotted end regions which are opposite one another. The two slotted end regions can be provided on axially opposite sides of the outer tube.

The invention is also directed to an actuator with at least one device according to one of claims 1 to 6.

Figur 1:

eine Außenansicht einer erfindungsgemäßen Vorrichtung;

Figur 2:

eine Längsschnittansicht einer erfindungsgemäßen Vorrichtung; und

Figur 3a und 3b:

Detailansichten zur Kopplung der einzelnen Komponenten der erfindungsgemäßen Vorrichtung.

Further details and advantages are explained using the embodiment shown as an example in the figures. show:

Figure 1:

an external view of a device according to the invention;

Figure 2:

a longitudinal sectional view of a device according to the invention; and

Figure 3a and 3b:

Detailed views of the coupling of the individual components of the invention Contraption.

figure 1 shows an external view of a device according to the invention, with an outer tube 7 of the cylinder of the device being shown on the outside, at each of its two axial end regions a cuff 5 for coupling at least some of the components of the Device is provided. In the lower part of the figure 1 Figure 1 shows an end portion of a piston 1, at least partially housed within the cylinder 7, which may include an eyelet or bushing for coupling the device to further equipment. At the opposite portion of the device a second boss or passage is shown which may be associated with a partially visible cylinder head 4 which may be at least partially received by the upper boot 5 .

figure 2 Figure 1 shows a longitudinal sectional view of a device according to the invention, in which a piston 1 is slidably mounted within the complex cylinder of the device. In this case, the cylinder comprises an inner tube 6 and an outer tube 7 surrounding the inner tube 6, which can be arranged coaxially to one another. The piston 1 has a piston head 2 which is slidably mounted within the inner tube 6 . A seal 10 can seal the sealing gap between the piston head 2 and the inner tube 6 .

A cylinder head 4 can be designed to be coupled to both pipes 6,7. For this purpose, an in particular cylindrical elevation 41 can be provided in an axially central region of the cylinder head 4, in the lateral surface or in the lateral surface area of which a seal 11 can be provided. The seal 11 can be designed to seal the sealing gap between the elevation 41 and the inner tube 6 . The cylinder head 4 can also comprise a radially inwardly curved section on a radial outside and in particular on a radially furthest arranged surface, against which the outer tube 7 can rest with its slotted end area 71 . In this curved area of the cylinder head 4, the slotted end area 71 of the outer tube 7 can be pressed against the cylinder head 4 by the sleeve 5, with the slotted end areas 71 or the slotted end area 71 can be curved radially inwards.

On the side of the device opposite the cylinder head 4, a piston rod bearing 3 is provided, in which the piston rod 1 is displaceably mounted. The sealing gap between the piston rod 1 and the bearing 3 can be sealed by at least one seal 8 . An embodiment with three corresponding seals 8 is also conceivable.

Similar to the area of the cylinder head 4 , at least the outer tube 7 can be pressed against the piston rod bearing 3 by a further sleeve 5 . The corresponding explanations for the cylinder head 4 apply analogously to the piston rod bearing 3.

As in the case of the cylinder head 4, a seal 9 for sealing the corresponding sealing gap can also be provided between the piston rod bearing 3 and the inner tube 6. The collar 5 can be connected to at least the outer tube 7 in a non-positive and positive manner. According to the invention, the collar 5 is pressed onto the outer pipe. It is not conceivable according to the invention to screw the sleeve 5 to the respective components with the rod bearing 3 and/or with the cylinder head 4 and/or to couple them in some other way.

Figures 3a and 3b show the corresponding coupling area of the cuff 5 in a lateral or perspective exploded view. The slotted end regions 71 of the outer tube 7 are slotted in the axial direction, and in particular identical tongues can be machined out of the outer tube 7 . The tongues can be made in one piece with the rest of the structure of the outer tube 7 . It is also conceivable here that both tubes 6.7 each have their own sleeve 5 on, for example, the piston rod bearing 3 and/or be pressed onto the cylinder head 4, wherein the two sleeves 5 can be at least partially nested and can include, for example, passages or at least one passage through which the piston rod bearing 3 mounted on the inside or the cylinder head 4 mounted on the inside can be passed through the sleeves 5 to the outside. The cuffs 5 can be manufactured accordingly with different diameters.

The inner tube 6 and/or the outer tube 7 can be made of a fiber-reinforced plastic. Designs are also conceivable in which one of the tubes 6, 7 is made of one material, while the other tube 6, 7 is made of a different material.

The inner tube 6 and the outer tube 7 are closed in their respective top area or bottom area, i.e. their openings or sections that exist axially on the outside, by means of the cylinder head 4 and by means of the piston rod bearing 3 .

For this purpose, in particular planar and further closure sections, in particular arranged parallel to one another, can be provided on the cylinder head 4 and/or on the piston rod bearing 3 . These can be circular or ring-shaped and arranged concentrically to one another.

The invention may relate to a hydraulic cylinder or actuator. The cylinder tube provided is made in two parts. An inner tube 6 is mounted inside an outer tube 7 .

The tubes can be made of fiber-reinforced plastic or metal. The inner tube 6 is closed by the piston rod bearing 3 and the cylinder head 4.

The cylindrical outer tube 7 can be pushed or positioned over this internal structure. The outer tube 7 can be slotted at both ends.

The tongues created by the slots can be pressed firmly onto the rounded outer contours of the piston rod bearing 3 and/or the cylinder head 4 with a fiber composite sleeve 5 which is pressed on from the outside.

An additional introduction of adhesive at the joints is possible.

The adhesive can be used to increase the strength of the bond and also as a seal be used. The outer tube 7 can represent a tie rod in this combination. However, it can absorb compressive forces. The inner tube 6 absorbs the hydraulic pressure forces and can also be prestressed. A pressure-resistant filler made of plastic, wood or metal can also be introduced between the inner and outer tube 6, 7 in order to increase the rigidity or buckling resistance.

The outer tube 7, which is designed in particular as a fiber composite tube, can function as a tie rod, which can be pulled in over curves of the end pieces, in particular with collars 5 pressed on. In the present case, the term end pieces can refer to the cylinder head 4 and/or to the piston rod bearing 3 .

According to the invention, there can be a non-positive and positive connection between at least the outer tube 7 and the cylinder head 4 and/or the piston rod bearing 3, which makes it possible to introduce the tensile and compressive stresses into the end pieces.

Furthermore, when used on a hydraulic cylinder, the separation of the force absorption into buckling/bending forces and pressure forces from fluid pressure is effected.

Advantageously, a variable modular system for manufacturing the cylinder-piston device can also be provided, in which the use of tube blanks that are easy to manufacture is possible. At least some of the components or the semi-finished products can also be produced in a cost-effective and flexible continuous production process. Overall, the geometry according to the invention increases the area moment of inertia in the load case.

Claims (7)

1. Device, comprising

   a cylinder,

   wherein the cylinder comprises an outer tube (7) with at least one end region (71) and an inner tube (6), which is mounted inside the outer tube (7) and is shorter than the outer tube (7),

   a piston,

   a piston rod,

   a cylinder head (4) for closing a first end region of the inner tube (6) and of the outer tube (7),

   a piston rod bearing (3) for closing a second end region of the inner tube (6) and of the outer tube (7) and for supporting the piston rod (1) for movement in the inner tube (6), and

   a sleeve (5), which is designed to secure the at least one end region (71) of the outer tube (7),

   characterised in that

   the outer tube with the exception of the at least one end region (71) is cylindrically formed,

   the at least one end region (71) of the outer tube (7) is slotted in the axial direction,

   the sleeve is designed to secure the slotted end region of the outer tube on the cylinder head (4) or on the piston rod bearing (3) in that the sleeve (5) is arranged from outside on tongues of the outer tube (7), and

   the sleeve (5) is pressed from outside onto tongues of the outer tube (7).
2. Device according to claim 1, characterised in that the inner tube (6) and/or the outer tube (7) and/or the sleeve (5) are made from a fibre-composite plastic and/or from a metal.
3. Device according to one of the preceding claims, characterised in that adhesive is provided in the region of the tongues.
4. Device according to one of the preceding claims, characterised in that a pressure-resistant filler, consisting in particular of plastic, wood and/or metal, is provided between the inner tube (6) and the outer tube (7).
5. Device according to one of the preceding claims, characterised in that the inner tube (6) is mounted concentrically with respect to the outer tube (7).
6. Device according to one of the preceding claims, characterised in that the outer tube (7) comprises two slotted end regions (71), which face each other.
7. Actuator comprising at least one device according to one of claims 1 to 6.

Images