CN1170377A - Screw driving-in process - Google Patents

Abstract

In a process for driving in a self-boring, self-piercing, thread-shaping or thread-cutting screw, an axial percussion effect (6) is added to the rotary drive (7) during the hole boring step. During the succedent thread-shaping step, the axial percussion effect is stopped and only the rotary drive remains.

Description

The method of mounting screw

The present invention relates to a kind of installation from boring or from pore-forming and have screw thread of one's own or the method for tapping screw thread screw, this screw has drilling part or becomes bore ends and with having of one's own or the bar section of tapping screw thread, connect an axial percussion by screw in boring or pore forming process when adopting this installation method.

In DE-A1478914, set forth a kind of above-mentioned method.Percussion only is made up of in order to form unique one-shot that the hole applies a kind of in this known method.Screw is screwed into workpiece after this.This known method only in this way could be used when thin workpiece, promptly adds a block at reverse side, so that applying the flexural deformation that prevents workpiece material when impacting for pore-forming.Such block is set means together additional work step, prolong the set-up time, in addition this possibility neither always be arranged.When mounting screw, always note up to now in addition, end boring procedure before the process that forms screw thread begins because with the corresponding feed speed of lead obviously greater than common boring feed speed.In boring procedure, should apply a corresponding axial force and also have a corresponding moment of torsion, after first pitch thread is screwed into, in fact only need to apply corresponding moment of torsion just on the contrary.

The objective of the invention is to: recommend the said method of a kind of beginning, it guaranteed to form best screw thread under the short set-up time, and best threaded engagement is arranged, particularly when thin workpiece material.

Reach like this this purpose according to the present invention: percussion is bored the bump campaign that produces like that by hammering and is caused, and keeps percussion in the screw forming of following or working angles, or reduces its impact strength, perhaps turns off fully.

By at first being this possibility according to the advantage that the inventive method reached: this method also can be used on the thin workpiece material, and needn't block be set at its reverse side, to prevent its flexural deformation, though by DE4301610 A1 and the known a kind of combination of impacting screwdriver or percussion drill and impacting screwdriver of DE4236819 A1, they can turn off percussion, but for install from boring or from pore-forming and have screw thread of one's own or the method for tapping screw thread screw both uncertain also improper.

For method of the present invention, no matter be equipped with shear action drilling partly or the end of chipless pore-forming connect an axial impact effect and all play advantageous effect equally.Drilling time or pore-forming time obviously shorten, and no matter all the same when being thin or quite thick workpiece.

Though drill bit also comprises an axial impact effect when holing on concrete as everyone knows except rotation drives, but the percussion of this form is obviously thought up to now and can not be realized in speciality circles by screw bore or pore-forming the time, therefore also never takes in.Estimate that this is because do not wish to have the Axial Shock Load of a suitable intensity fully in subsequently screw forming or working angles, because screw thread is axially correspondingly being widened in this case, therefore again can not talk secure fit or the good threaded engagement form between screwing and the workpiece.

Therefore contribution of the present invention just in time is, two work steps (just in boring or pore forming process by hammering bore the bump campaign that produces like that cause reduce percussion in percussion and the screw forming of following or the working angles or turn off fully) mutually combine.These different work steps are used on the mutual ground that is connected in a kind of independent assembling process, and this should regard a special progress as in the screw fitting limit.

By pressing method of the present invention even can only boring the bump sports pore-forming that produces like that with hammering without rotary actuation, particularly it can bring foregoing advantage when thin workpiece.

With a wood or wooden base plate the time, also can when being screwed into screw, keep percussion.But for example must reduce its intensity during the base plate of metal or turning off fully with one.

The good structure of the present invention constitutes the content of dependent claims.

For example in a kind of version of the present invention, can connect an axial percussion in boring or the rotary actuation during pore-forming to screw.Percussion boring or pore forming process by rotary actuation and stack can also improve.

According to this relation, with regard to reducing immediately the intensity of percussion or fully it being turned off, especially beneficial after the drilling of screw part or pore-forming end total penetrate (workpiece) and first pitch thread also is not screwed into the hole before.Switching or shutoff (percussion) are more accurate, timely, the cooperation of the screw that is screwed at last is also just more accurate, because this not only can process the hole an of the best, and reach especially good screw-threaded engagement each other between workpiece and the screwed bar section.

By in a kind of flexible program of the inventive method, from Axial Shock Load switch to the Axial Shock Load of a remitted its fury or turn-off percussion be after boring or pore forming process finish immediately by axial load reduce cause.Unexpected axial unloading can appear like this, promptly for example when the drilling part or become the prominent hole of bore ends processing, make end by boring procedure produce immediately, when unloading suddenly.This axially unloads (occurring suddenly or slowly no matter be) by can be as the starter of the mechanical signal or the signal of telecommunication in the method for the present invention, to reduce or to turn-off the axial impact effect fully.

According to another flexible program suggestion, the Axial Shock Load or the shutoff percussion that switch to a remitted its fury from Axial Shock Load are started by an adjustable-depth block.This flexible program by the inventive method also can be realized with fairly simple version, because Axial Shock Load is for example such when percussion drill or hammering brill, only just exists when applying corresponding axially back pressure.This back pressure disappears from screw after corresponding degree of depth block occurs, and carries out switching or the shutoff be scheduled to by the present invention.

To also being described further by method of the present invention, this will carry out by means of the screw that is housed to workpiece here in the narration below.In the accompanying drawing:

Fig. 1 just is put into the side view of the screw that workpiece gets on;

Fig. 2 is after pore-forming, and this screw before screw chasing or forming process just;

Fig. 3 wherein particularly can see screw-threaded engagement each other by the amplification view of workpiece and screw.

Here drawn be provided with one from pore-forming and threaded screw 1 and be shrunk to tip or be similar to end 2 pointed shape, chipless ground pore-forming.Next exists the bar portion 4 and the retained part 5 that is used to the instrument of loading onto that are provided with screw thread 3.

Among the figure from a screw 1 from pore-forming and screw thread.Here the end 2 and the respective threads 3 that have a chipless pore-forming.But the method for narrating here can be applicable to all with method for distinguishing from pore-forming or have the screw of screw thread of one's own, and also can install in this way in addition from boring and tapping screw thread screw.Now no matter be during at boring procedure or in pore forming process, perhaps still there is the work of smear metal ground on chipless ground when screw forming or cutting, does not all have great relation for this method.Test shows, this method also can be effectively applied to the self-drilling screw that cuts especially.Here exist drill bit or the corresponding drill insert made by the metal forming method all same effective regardless of the free end at screw.Equally also show, with this method with just in time also have the end of chipless pore-forming that the screw of being made by non-corrosive material fully can be installed.Generally always attempt, for the local at least bolt structure of making by non-corrosive material at least drill bit make by a kind of material that hardens so that can apply suitable drilling effect.Therefore all the time must expensive welding scheme for screw.

Can be purely and simply make by adopting the method narrated also can adopt here, have the screw that has bore ends 2 or other versions of one's own by a kind of non-corrosive material.

Therefore method described here is: drive percussion that works at axis direction 6 of access in pore forming process the rotation of screw 1.Screw also is subjected to an axial impact loading 6 except rotatablely moving 7.Thereby can be than forming corresponding hole 8 at workpiece 9 process time of much shorter up to now.But with method described here the time, also can only finish pore forming process by percussion fully.Insert later on rotary actuation to form screw thread at pore-forming then.

In case finish hole 8, can see such as Fig. 2, stop percussion according to another work step, so that only have rotary actuation 7 to work.This means optimal scheme in the hole 8 of workpiece 9, forming screw thread 3, because so just do not have axial impact or oscillating movement.Therefore, be fitted in exactly on screw thread 3 surfaces of bar section 4 in the threaded engagement that hole wall forms.

In back to back screw forming or working angles, all can turn-off percussion in common or in fact various versions and the application possibility.But might be in follow-up screw forming or working angles extreme other application scenario one small, comparing the percussion that its intensity obviously weakens with boring procedure also is useful.Obtain an additional Beneficial Effect by Axial Shock Load, because by percussion no matter at pore-forming or in the extraly distortion downwards of hole wall during just in time at thinner workpiece 9 of when boring, so that 8 parts produce a kind of crimping 10 in the hole.Thereby itself forms a sizable axial region when relatively thinner workpiece 9, and the screw thread 3 of screw 1 bar portion 4 can be embedded in its inside.

With this method the time, fully can, a percussion that works in direction of rotation superposes beyond the axial impact effect, in fact it does not have any effect to boring or pore forming process, but can bring extra advantage in back to back screw forming or working angles.

Secondly, if the shutoff of percussion or switch to a corresponding percussion that reduces of its intensity can be exactly at bit part or have of one's own and carry out after bore ends 2 penetrates fully, method described here is of great use.Switching or shutoff should be carried out before first tooth of screw thread 3 is shot as far as possible.

To switch or shutoff (percussion) in order starting, to provide various, the scheme that can adopt valuably.For example it is contemplated that unexpected axial unloading is started switching immediately or turn-offed after boring procedure or pore forming process end.If for example also connect as shown in the figure one section not threaded bar section 11 on end 2, this also is possible.In case end 2 pore-forming on workpiece 9 is complete, just produce a unexpected axial unloading, because the unexpected sinking of not threaded bar section's 11 present axial compressive forces owing to also continuing applying is by hole 8.Can make full use of this unexpected unloading by corresponding mechanical organ or electrical control gear, switch or the effect of shutoff axial impact so that cause.But if there is the degree of depth block of a corresponding preset, just can obtain so the possibility of another kind of machinery, in case degree of depth block is run into workpiece 9, just produce an axially unloading, finish axial impact by normal mechanical approach then.Can certainly be with switching or the cut-off method of any electric or electronics, wherein controlling accordingly parameter can directly obtain from the rotary driving part branch.

Claims (5)

1. install from boring or from pore-forming and have screw thread of one's own or the method for tapping screw thread screw, screw have a bit part or become bore ends and one with the bar section that has screw thread or tapping screw thread of one's own, in this way the time, in boring or pore forming process, insert a percussion that is axially working by screw, it is characterized in that: percussion (6) is caused by the bump campaign that probing capitate formula produces, and keeps this percussion (6) or reduce its intensity or fully shutoff in back to back screw forming and working angles.

2. by the method for claim 1, it is characterized in that: drive access in the percussion that axially works (6) in boring or pore forming process, for the rotation of screw (1).

3. by claim 1 or 2 method, it is characterized in that: percussion intensity weaken or its shutoff at the bit part of screw (1) or after becoming bore ends (2) to penetrate fully, and before first pitch thread is not also shot hole (8), carry out.

4. by each method of claim 1 to 3, it is characterized in that: switch to the axial impact effect (6) that an intensity weakens or turn-off percussion (6) from axial impact effect (6) and after boring or pore forming process finish, cause by axial no-load starting immediately.

5. by each method of claim 1 to 3, it is characterized in that: switch to axial impact effect (6) that an intensity weakens from axial impact effect (6) but or turn-off percussion and can cause by the degree of depth block starting of a preset.

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