DE10334245A1 - Screwing tool for screwing sensitive components and method for this - Google Patents

Abstract

The invention consists in presenting a screwing tool which comprises a protractor in addition to a torque meter, so that after reaching a Drehmomentschwellwerts the screwing additionally by a defined angle, which is greater than 0 °, is rotated further. DOLLAR A In addition, methods are presented, which consist of a sequence of torque-controlled and angle-controlled Einrehschritten. DOLLAR A With the invention, a fixed screw without or with only slight or defined deformation of the mounting element is achieved.

Description

The The invention relates to a screwing tool for screwing in a sensitive one Mounting element and a method for this.

modern Screwing systems set the degree of screwing by means of torque monitoring or juggling safely.

at the torque monitoring the value of the torque is measured and the mounting element is not further than until reaching a predetermined torque, the Target torque, turned.

at the Winkelzug a certain target rotation angle is given and the mounting element screwed only at this Eindrehwinkel.

With These measures should ensure that the mounting element, which is a screw, a nut or a screw functional component, such as a spark plug, an electrode or a valve can act, on the one hand so tightly screwed to the desired Fixation to achieve, on the other hand, the screw not so firmly executed that will damage it comes at the threads or even at the component.

disadvantage of the prior art

at the angle pull method is used despite the set target rotation angle the mounting element frequently not to the desired Screwed angle. The reason for this is that the screwing tool even when turning undergoes a twist, which in the angle measurement disregarded. This flaw can not be overcome by adding a lump sum to the Target rotation angle to be corrected because the torsion of the screwing a complex process. The actual angle of insertion can be in retrospect, only determine that after settling the screwing from the mounting element rest relaxation, so the turning back the twisting of the screwing tool that occurred during the screwing process was measured and subtracted from the target rotation angle. An exact preset the angle of rotation is not possible. The angle suit method is mainly suitable for expansion bolts, so mounting elements that not susceptible to it for one Torsion are.

at the torque monitoring depends on the degree the screw connection is strongly dependent on the involved screw surfaces, So of used greases, soiling, manufacturing tolerances The scattering of the angles of rotation therefore varies over one huge Area.

It On the one hand, it may happen that mounting elements are screwed in too tightly be, and possibly a damaging one Undergoing deformation. On the other hand, it is possible that only a temporary Stiction between the bolting surfaces of the mounting element and its bolting partner, e.g. by a dirt particle, for a sufficient Torque ensures that the rotation is terminated too early and it does not come to a sufficient stop or contact.

Task of invention

The The object of the invention is a durable screw without or with only minor, or to achieve defined deformation of the mounting element.

Solution of task

The solution the task is to introduce a screwing tool, the in addition to a torque meter includes a protractor, so after reaching a predetermined value for the torque, the torque threshold, the Screwing tool additionally by a defined angle greater than 0 degrees, is rotated further.

The The object is further achieved by a method that consists of a sequence of consists of torque-controlled and angle-controlled insertion steps.

Advantages of invention

One An essential advantage of the invention is that the screwing tool according to the invention allows a screw connection, at the one possible Deformation of the mounting element either does not take place, or at least not dependent on the friction between the Verschraubungsflächen.

If the mounting element is initially rotated only to reach a torque threshold, it can be ensured by a suitable choice of this threshold that the mounting element is not affected in such a suit strength. However, in order to achieve a sufficient fixation of the mounting element, the mounting element is still rotated by a defined and controllable angle with the protractor. This is chosen so that the addi torque, which is exerted by the further rotation by the angle, causes no or a predetermined deformation, which affects the subsequent functioning of the mounting element.

The Screwing tool according to the invention can be designed as a hand-held tool that has a Torque and angle display for one Operator has. It can also be used as a fully automatic tool in a production line be used or used as a tool element of a robot become. For the automati cal use, it is beneficial if the screwing over a Interface has, by means of which the torque threshold and the defined rotation angle can be entered.

Favorable The invention is further developed by the screwing over a Control unit has, the dependent one or more torque thresholds a successive Sequence of torque and angle controlled screwing allowed.

Of the Advantage of the invention claimed Method is also that a screwing is made possible in which a fixed screwing achieved while the Assembly element is treated gently. Depending on what it is For example, care must be taken when the mounting element is be that there is no torsion of the mounting element or that the screw is releasable again.

Around only temporary disorders to prevent in the torque-controlled screwing, can be an extra Step introduced become. This is after the suit of the mounting element up to a predetermined torque, the screw initially released again, then the perform torque-controlled screw again.

At the Be solved the bolting surfaces of the mounting element and its Verschraubungspartners, so the contact surfaces the elements to be screwed, smoothed.

It may be due to dirt particles between the Verschraubungsflächen, a Tilting of tool to mounting element, hardening of the Lubricant or other undesirable influences the screw briefly creates a torque that reaches the threshold and triggers the termination of the screwing process. It comes in this case to a so-called "spurious" increase in torque.

Becomes the screwing actually terminated, so the connection may be not tight enough. To counteract this, the Verschraubungsflächen the Loosen against each other and the screwing of the now smoothed Verschraubungsflächen again performed torque controlled.

To This process can the screw connection by a predetermined angle be continued, either by a negative angle, causing the screw connection again something is loosened to a positive angle, according to the above described method, or by the angle 0 degrees, which is a pure torque-controlled screwed corresponds.

The inventive method is advantageously developed by the solution of the screwing process only up to a certain second lower threshold torque is made. With the second threshold can be ensured be that solution of the mounting element is not complete takes place, but the mounting element in contact with his screwing remains. This prevents slipping and re-starting avoided.

Further advantageous embodiments will become apparent from the following description, Drawings and the claims out.

drawings

It shows:

1 the relationship between torque and mounting angle in the conventional torque-controlled fitting;

2 the relationship between torque and mounting angle in successively carried out torque and angle controlled screwing.

embodiments

1 shows the relationship between torque plotted on the y-axis 1 and the angle of rotation about which the mounting element is rotated, hereinafter referred to as mounting angle, plotted on the x-axis 2 in the conventional torque-controlled screwing. Depending on the friction between the bolting surfaces of the mounting element and its bolting partner occurs when the torque setpoint 3 , in this example 50 Nm, at different mounting angles.

In the diagram are several mounting curves 4 shown, which show the measured torque at a certain mounting angle for different screwing.

The slopes of the marked assembly curves 4 arise due to various friction between the screw surfaces of the mounting element and its bolting partner, lubricants, surface finishes, manufacturing tolerances, etc., on which virtually no influence can be taken. In this example, a considerable spread arises 5 the mounting bracket.

2 shows the relationship between torque plotted on the y-axis 11 and mounting bracket, plotted on the x-axis 12 with successively carried out torque and angle-controlled screwing. The slopes of the mounting curves 14 correspond to those in 1 However, the curves are shifted so that the reference angle 16 for all curves at a certain torque 13 The curves are not as in 1 cut at the point where the torque and the mounting angle have the value 0.

The mounting elements are initially only up to a torque threshold 13 turned, in this example 10 Nm, then by a predetermined angle 17 , here 12 degrees, further rotated.

The spread of the mounting bracket 15 is significantly smaller, as it has the smaller torque threshold 13 related.

Claims (6)

Screwing tool for controlled screwing of screwable mounting elements comprising a screw spindle and a torque meter, characterized in that the screwing tool comprises a protractor, so that after reaching a torque threshold, the screwing tool is further rotated by a defined angle. Screwing tool according to claim 1, characterized in that that the screwing tool comprises a control unit that controls the input of at least one torque threshold and at least one Angle of rotation and or the display of the instantaneous torque as well Angle of rotation allows. Screwing tool according to one of the preceding Claims, characterized in that the screwing tool is a control unit includes a successive sequence of torque controlled and angle-controlled screwing allowed. Method for the controlled screwing of screwable mounting elements with a screwing tool comprising a screw spindle and a torque meter, characterized in that - a torque threshold value ( 15 ) and a defined angle ( 16 ), which is greater than 0 degrees, can be specified, - the mounting element up to a torque threshold ( 15 ) is screwed in, - the mounting element by the defined angle ( 16 ) is further screwed. Method for the controlled screwing of screwable mounting elements with a screwing tool comprising a screw spindle and a torque meter, characterized in that - a torque threshold value ( 15 ) and a defined angle ( 16 ), - the torque is measured, - the mounting element up to a torque threshold ( 15 ) is screwed in, - the mounting element is released again, - the mounting element again up to a torque threshold ( 15 ) is screwed in, - the mounting element by the defined angle ( 16 ) is further screwed. Method for the controlled screwing of screwable mounting elements with a screwing tool comprising a screw spindle and a torque meter, characterized in that - a first upper torque threshold, a second lower torque threshold and a defined angle are given, - the torque is measured, - the mounting element until to a first upper torque threshold ( 15 ) is screwed in, - the mounting element is released up to a second lower torque threshold, - the mounting element again up to a first upper torque threshold ( 15 ) is screwed in, - the mounting element by the defined angle ( 16 ) is further screwed.