WO2005106277A1

WO2005106277A1 - Free-running device

Info

Publication number: WO2005106277A1
Application number: PCT/AT2005/000149
Authority: WO
Inventors: Heinz Kölbl; Krasser Franz
Original assignee: E-Ventures Automation Gmbh
Priority date: 2004-04-30
Filing date: 2005-04-29
Publication date: 2005-11-10

Abstract

Disclosed is a free-running device, particularly a free-running device for a clamping block, between a hub (7) and a shaft (3). In order to be able to start transmitting torque in a slip-free manner, said free-running device is characterized in that a preloading mechanism (17) which causes a relative rotary movement in the blocking direction of the free-running device is provided between the hub (7) and the shaft (3).

Description

freewheel

The invention relates to a freewheel, in particular a clamping block freewheel, between a hub and a shaft.

Freewheels of this type enable the transmission of very large torques, the load capacity also increasing with the increase in the torque to be transmitted.

A difficulty arises with freewheels of this type in that in the freewheel position, i.e. when there is no clamping action, when applying a torque to the hub or the shaft, reliable clamping does not immediately occur, but only after a more or less large relative rotation movement between the Hub and the shaft takes place.

The invention aims at avoiding this disadvantage and has as its object to create a freewheel which can be used for torque transmission immediately after the application of a torque.

According to the invention, this object is achieved in that a pretensioning device which effects a rotational relative movement in the blocking direction of the freewheel is provided between the hub and the shaft.

From DE 40 32 915 AI a connection between a shaft and a hub is known in which a non-rotatable connection is made at least in one direction of rotation and at least up to a predetermined maximum torque. This connection is achieved by clamping bodies which are supported with one another via resiliently deformable intermediate members. According to this document, these elastically deformable intermediate members are located between the clamping bodies, as a result of which the clamping bodies are constantly pressed into a clamping position.

According to a preferred embodiment, the pretensioning device according to the invention is formed by a pin which is resiliently supported on the hub and extends approximately tangentially to the circumferential direction of the shaft and which can be supported with its end facing the shaft in a recess, in particular in a longitudinal groove, of the shaft with the aid of spring force is.

If the recess is designed as a longitudinal groove, the hub can be displaceable relative to the shaft or the shaft relative to the hub, and the pretensioning device can be in each Sliding position be effective. A particular advantage of this embodiment can also be seen in the fact that even in the case of vertically arranged shafts, an automatic displacement due to the dead weight can be effectively prevented.

A preferred embodiment of the freewheel is characterized by a relaxation device acting on the hub or shaft for generating a rotational relative movement counter to the blocking direction of the freewheel, the relaxation device preferably being designed as an actuating body which can be moved against the hub or shaft and which adjusts the hub or shaft around a predetermined angle of rotation moves against the blocking direction of the freewheel, preferably under limitation of the torque applied by the actuating body.

The invention further relates to roller shears, in particular for longitudinally dividing material webs, for example sheet metal webs, with at least two roller knives interacting in pairs, each of which can be displaced along a knife shaft by means of an actuating device and can be fixed and detached in a predetermined position on the knife shaft by means of a tensioning device, wherein the knife shafts are arranged parallel to each other.

A roller shear of this type is known for example from AT 006.462 U2. In this known device, the roller knives are mounted on the knife shafts by means of hydraulic expansion chucks and can be fixed or detached with respect to these knife shafts. The actuating device used to move the roller knives has a slide which can be displaced along a guide track, which guide track is provided parallel to a knife shaft and which slide is equipped with a driving device for a roller knife. The driving device can be brought into and out of engagement with a roller knife.

Hydraulic chucks are very expensive construction elements and are subject to a certain amount of fatigue due to wear of these seals, especially since seals have to be provided. In addition, the ingress of foreign bodies or liquids into the chuck can easily lead to malfunctions, especially since, particularly when slitting sheet metal sheets lengthways, soiling often occurs during a cutting process. Furthermore, these chucks are temperature sensitive.

Hydraulic chucks have a very high run-out accuracy for the longitudinal cutting of material webs, in addition they also offer a high concentricity, but for the longitudinal cutting of material webs, which only require an exact Cutting gap arrives, is not required. The constancy of the cutting gap depends only on the runout accuracy and not on the runout accuracy.

The invention aims to avoid these disadvantages and difficulties and has as its object to create a roller shear of the type described above, which is simple in construction and less prone to failure and also inexpensive and enables an exact adjustment of the roller knife.

This object is achieved in accordance with the invention in that the tensioning device is formed by a coupling arranged between a roller knife and the associated knife shaft according to the principle of a freewheel, in particular a clamping block freewheel, which acts with one between the knife shaft and a roller knife. Biasing device is provided.

Couplings according to the principle of a freewheel, in particular according to the principle of a clamping block freewheel, have high axial run-out accuracy, which ensures a constant cutting gap. A slightly less precise runout compared to a hydraulic chuck is completely negligible for roller shears, since, as mentioned above, the runout is insignificant for the cutting gap.

A preferred embodiment is characterized by the following features: a base body which is displaceable on a knife shaft and provided with a roller knife - with clamping bodies arranged around the circumference of the knife shaft, which are arranged in a cavity of the base body and which have a clamping contact between the knife shaft and in a clamping position condition the base body with the interposition of the clamping body and - allow a sliding movement between the knife shaft and the base body in a release position.

The clamping bodies are preferably each pivotable about their axes, which are directed parallel to the axes of the knife shafts, from the clamping position to a release position and back, the pivoting direction being directed in the clamping position in the opposite direction to the direction of rotation of the roller knives during the cutting process.

A bias between the knife shaft and the base body forming a hub is preferably achieved in that one between the base body and the Knife shaft provided pretensioning device is provided, which acts in the clamping position on the base body opposite the knife shaft opposite to the direction of rotation of the roller knives during the cutting process, with pivoting of the pivotable clamping body into the clamping position, the preloading device expediently being supported by a spring on the base body and extending approximately in the circumferential direction Knife shaft extending pin is formed, which can be supported with its end facing the knife shaft in a longitudinal groove of the knife shaft by means of spring force.

Further preferred features of the tensioning device are as follows: an adjusting shaft directed parallel to a knife shaft, with the aid of which an adjusting body arranged on the adjusting shaft can be pressed against a base body, the adjusting body in the pressing position moving the base body relative to the knife shaft in the direction of rotation of the roller knives during the cutting process, with the knife shaft at a standstill and swiveling the clamping body into the release position.

An actuating device for a roller shear according to the invention is expediently characterized in that an adjusting spindle is provided parallel to the knife shafts, with the aid of which the adjusting bodies can be adjusted in the axial direction of the knife shafts while taking the base body along, preferably the two adjusting bodies respectively associated with a knife shaft by means of a carrier are connected to one another for the purpose of synchronous adjustment along the axis of a knife shaft.

In order to avoid overturning the base body with respect to the knife shafts, the adjusting bodies have engagement rollers for contact with the respective base body and the engagement rollers are mounted on the adjusting body by means of slip hubs for the transmission of a predetermined load torque.

A preferred embodiment is characterized in that the actuating shaft is formed by a torque ball bushing shaft and the actuating body can be pivoted via a ball screw drive in contact position with a base body and in the opposite direction about the actuating shaft.

The roller shears according to the invention make it possible for the two roller knives, which are each arranged and interacting on a knife shaft, to be of identical design. They only need to be arranged in reverse order. This gives one Particularly cost-effective construction, with storage of the roller knives also being simplified.

The invention is explained in more detail below using an exemplary embodiment which is illustrated in the drawing. 1 illustrates a partially sectioned side view of two roller knives interacting in pairs, arranged on knife shafts, in the state fixed to the knife shafts, FIGS. 2, 3 and 4 each show sectional representations according to the section lines II-II, III-III, IV-IV, 2A and 3A illustrate details A of FIGS. 2 and 3, respectively. FIG. 5 shows a view in the direction of arrow V of FIG. 4. FIGS. 6 and 7 and 6A and 7A and 8 and 9 show the roller knives in a state analogous to FIGS. 2 to 5 in the state released from the knife shafts.

In the case of roller shears for the longitudinal division of material webs, such as sheet metal webs 1, at least two paired roller knives 2 are arranged on two mutually parallel knife shafts 3 and can each be displaced along the knife shafts 3 by means of an actuating device 4, for example for setting a predetermined cutting width 5, and they can be fixed in each case by means of a clamping device 6 for the purpose of transmitting the cutting forces from the drivable knife shafts 3 to the roller knives 2 in a specific position on the knife shafts 3 corresponding to the targeted cutting width 5. For adjustment to a different cutting width, the roller knives can also be detached from the knife shaft 3 by means of the clamping devices 6, so that the roller knives 2 can be displaced along the knife shaft 3 by means of the adjusting devices 4.

The roller knives 2 are each firmly anchored to a base body designed as a hub 7, for example screwed by means of fastening rings 8, which base bodies 7 are axially displaceable with very little play relative to the knife shaft 3 with slide bearing bushings 9. An annular cavity 10 is provided between each grand body 7 and the associated knife shaft 3, in which elongated clamping bodies 11 with axes 12 parallel to one another, which are also parallel to the axes 13 of the knife shafts 3, are provided. The clamping body 11 can completely occupy the available annular space 10 or else be evenly distributed around the circumference by means of a suitable support cage or a clamping ring.

The clamping body 1 1 have a cross section which is partially cylindrical, each clamping body 11 two diametrically opposite one another, via the Has cylindrical shape protruding clamping lugs 14. These clamping lugs 14 can, as can be seen in particular from FIG. 1A, come to rest on the hardened surface of the knife shaft 3 and on a hardened steel sleeve 15 arranged in the interior of the base body, which is fixed on the base body 7, when the clamping bodies 11 are pivoted in a certain direction about their longitudinal axes 12 (see FIG. 2A). The clamping position is achieved in that the clamping bodies 11 are pivoted in the opposite direction to the direction of rotation of the knife shaft 3 when cutting, which is achieved by a loose contact (low friction) between the base bodies 7 and the clamping bodies 11 and the knife shafts 3. Loose contact is achieved by their own weight, even if there is little play around the clamping bodies 11 in the annular space 10. The drive direction of the knife shafts 3 during cutting is illustrated by arrows 16.

The clamping body 11 thus fix the base body 7 with respect to the knife shafts 3, the greater the cutting forces that are required for cutting the sheet metal web 1; they are self-locking. The torques required for the cut and also the transverse forces which occur, which could cause the cutting roller knives 2 to be axially pushed apart, can be transmitted without any problems since, as mentioned, the clamping forces increase due to the increasing pivoting of the clamping bodies 11 due to the increasing moment load.

In order to prevent the roller knives 2 from being displaced when the knife shafts 3 are stationary or when the knife shafts 3 are retracting when a sheet metal web 1 is pulled out when the knife shafts 3 are lifted off, a pretensioning device 17 is provided, which consists of a pin 19 supported against each base body 7 by means of a spring 18 which pin 19 causes the base body 7 to rotate slightly relative to the knife shaft 3, for which purpose the pin 19 engages with a protruding nose 20 in a longitudinal groove 21 of each knife shaft 3 and the base body 7 counter to the direction of rotation 16 of the knife shaft 3, which is adhered to during the cutting process (cf. FIG. 3A).

As can be seen from FIG. 3, two biasing devices 17 are provided on each base body 6 diametrically opposed to one another diametrically about the axis 13 of each knife shaft 3. These pretensioning devices 17 cause the clamping bodies 11 to jam, that is to say each base body 7 is fixed with respect to the knife shafts 3 with a specific force applied by the spring 18 of the pretensioning device. For the axial displacement of a roller knife 2 relative to the knife shaft 3, it is necessary to rotate the base body 7 against the knife shaft 3 against this pretensioning device 17, so that the clamping body 11 from the clamping position into a release position - with the loose contact described above - as shown in FIG 6 and 6A is illustrated. For this purpose, an adjusting shaft 22 arranged parallel to a knife shaft 3 is provided, with the aid of which an adjusting body 23 arranged on the adjusting shaft 22 can be pressed against a base body 7, specifically when the knife shafts 3 are stationary.

Each actuating body 23 has, on a projecting extension 24 that is lever-like against the base body 7, an engagement roller 25 that can be brought into engagement position with the base body 7 and that serves to transmit a specific torque to the base body 7. In order to limit this torque, the engagement roller 25 is mounted on the actuating body 23 by means of a slide hub 26 which is resiliently arranged with a spring 24 ′, for example realized by a disk spring 27. The actuating shafts 24 themselves are formed by a ball bushing shaft on which the actuating bodies 23 are connected via torque ball bushings 28 and plain bearing bushes 29 are mounted. According to FIG. 4, the adjusting bodies 23 or the engagement rollers 25 are out of engagement with the base bodies 7, according to FIG. 8, so that the clamping bodies 11 are moved in the release position and the roller knives 2 can be moved along the knife shafts 3.

Since the distance between the knife shafts 3 and the ball bushing shafts 22 is selected such that the engagement rollers 25 not only touch the friction surfaces 30 of the base bodies 7 when the adjusting bodies 23 are pivoted in, but also have to deflect them against the compressive force of the springs 24 ', the base bodies 7 of the engagement rollers 25 rotated accordingly. The plate springs 27 offer a slip torque that is somewhat greater than the required torque of the base body 7 against the pins 19 of the pretensioning devices 17.

Since the twisting angle (switching angle) between the cutter shaft 3 and the base body 7 which is necessary for becoming “free” or becoming “fixed” depends on numerous influences (diameter, temperature, lubrication, etc.), this switching process cannot be fixed Already after a slight twisting of a base body 7 by the engagement roller 25 engaging and pressed on the friction surface 30, the base body 7 will be “free”. For safety's sake, the base body 7 is rotated even further until shoulders 31 of the pins 19 rest against the base body 7 (see FIG. 7A). Since this cannot be predicted exactly and depends on which angle of hold was necessary during the previous adjustment, it is necessary to enable an even larger angle of rotation. For this reason, the engagement rollers 25 are also provided with the slip hub 26, which only slips when the angles of rotation exceed the stop of the shoulders 31.

The adjusting device 4, which has an adjusting spindle 32, is used to move the roller knives 2, with the aid of which the adjusting bodies 23 can be axially displaced via a nut 33 arranged on one of the adjusting bodies 23. In order to find sufficiency with a single adjusting spindle 32, the adjusting bodies 23 assigned to each knife shaft 3 are connected to one another by means of a carrier 34, so that these adjusting bodies 23 can only be adjusted jointly and synchronously.

Once the roller knives 2 have been brought into the desired positions, it is now sufficient to move the actuating bodies 23 away from the friction surfaces 30 of the base bodies 7 again by appropriate restoration via the ball bushing shafts 22. The preloading devices 17 installed in the base bodies 7 will now clamp the clamping bodies 11 again because of the effective pressure forces of the springs 18.

Claims

claims:

1. freewheel, in particular clamping block freewheel, between a hub (7) and a shaft (3), characterized in that between the hub (7) and the shaft (3) causes a rotational relative movement in the locking direction of the freewheeling biasing device (17th ) is provided.

2. Freewheel according to claim 1, characterized in that the pretensioning device (17) is formed by a pin (19) which is resiliently supported on the hub (7) and extends approximately tangentially to the circumferential direction of the shaft (3) and which is connected to the shaft (3) directed end (20) in a recess, in particular in a longitudinal groove (21), the shaft (3) can be supported by means of spring force.

3. Freewheel according to claim 1 or 2, characterized by an on the hub (7) or shaft (3) acting relaxation device (23) for generating a rotational relative movement against the blocking direction of the freewheel.

4. Freewheel according to claim 3, characterized in that the expansion device is designed as a movable body (23) against the hub (7) or shaft (3), which counteracts the hub (7) or shaft (3) by a predetermined angle of rotation Locking direction of the freewheel moves, preferably by limiting the torque applied by the actuating body (23).

5. Roller shears, in particular for slitting material webs, for example sheet metal webs (1), with at least two roller knives (2) interacting in pairs, each of which can be displaced along a knife shaft (3) by means of an adjusting device (4) and in a predetermined position on the knife shaft (3) can be fixed and detached by means of a clamping device (6), the knife shafts (3) being arranged parallel to one another, characterized in that the clamping device (6) is arranged between a roller knife (2) and the associated knife shaft (3) Coupling according to the principle of a freewheel, in particular a clamping block freewheel, is formed according to one or more of claims 1 to 4.

6. Roller shears according to claim 5, characterized by the following features: - a base body (7) which can be displaced on a cutter shaft (3) and is provided with a roller cutter (2) with clamping bodies (11) distributed around the circumference of the knife shaft (3), which are arranged in a cavity (10) of the base body (7) and which, in a clamping position, have a clamping contact between the knife shaft (3) and the base body (7) with the interposition of the clamp body (11) and allow a sliding movement between the knife shaft (3) and the base body (7) in a release position.

7. Roller shears according to claim 6, characterized in that the clamping bodies (11) are each pivotable about their axes (12), which are directed parallel to the axes (13) of the knife shafts (3), from the clamping position into one Release position and back, whereby the swivel direction in the clamping position is opposite to the direction of rotation (16) of the roller knife (2) during the cutting process.

8. Roller shear according to claim 6 or 7, characterized in that a pre-tensioning device (17) is provided between the base body (7) and the knife shaft (3), which in the clamping position opposes the base body (7) relative to the knife shaft (3) Direction of rotation (16) of the roller knives (2) is applied during the cutting process, with the pivoting clamping bodies (11) also pivoting into the clamping position.

9. Roller shear according to claim 8, characterized in that the pretensioning device (17) is formed by a pin (19) which is resiliently supported on the base body (7) and extends approximately in the circumferential direction to the knife shaft (3) and which is connected to the knife shaft (3 ) directed end (20) in a longitudinal groove (21) of the knife shaft (3) can be supported by means of spring force.

10 ^' . Roller shears according to one or more of claims 6 to 9, characterized by the following features: an adjusting shaft (22) directed parallel to a knife shaft (3), with the aid of which an adjusting body (23) arranged on the adjusting shaft (22) against a base body (7 ) can be pressed, with the actuating body (23) in the pressed position moving the base body (7) relative to the knife shaft (3) in the direction of rotation (16) of the roller knives (2) during the cutting process, namely when the knife shaft (3) is stationary and swiveling the Clamping body (11) in the release position.

11. Roller shear according to claim 10, characterized in that an adjusting spindle (32) is provided parallel to the knife shafts as the adjusting device (4), with the aid of which the adjusting bodies (23) while taking the base body (7) in the axial direction of the knife shafts (3 ) are adjustable, preferably the two adjusting bodies (23) each associated with a knife shaft (3) are connected to one another by means of a carrier (34) for the purpose of synchronous adjustment along the axis (13) of a knife shaft (3).

12. Roller shears according to one or more of claims 6 to 11, characterized in that the actuating bodies (23) have engagement rollers (25) for contact with the respective base body (7), and the engagement rollers (25) for transmitting a predetermined load torque by means of Sliding hubs (26) are mounted on the actuating body (23).

13. Roller shear according to one or more of claims 10 to 12, characterized in that the actuating shaft (22) is formed by a torque ball bushing shaft and the actuating body (23) via a ball screw drive in contact position with a base body (7) and opposite to the actuating shaft ( 22) is pivotable.

14. Roller shear according to one or more of claims 5 to 13, characterized in that the two roller knives (2) arranged and interacting on a knife shaft (3) are identical in design, but are arranged reversely to one another.