CN110730872B - Component with screw stud and method for connecting components - Google Patents
Component with screw stud and method for connecting components Download PDFInfo
- Publication number
- CN110730872B CN110730872B CN201880015424.1A CN201880015424A CN110730872B CN 110730872 B CN110730872 B CN 110730872B CN 201880015424 A CN201880015424 A CN 201880015424A CN 110730872 B CN110730872 B CN 110730872B
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- stud
- thread
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- 238000000034 method Methods 0.000 title claims description 8
- 238000001746 injection moulding Methods 0.000 claims abstract description 12
- 239000011796 hollow space material Substances 0.000 claims abstract description 11
- 238000010079 rubber tapping Methods 0.000 claims abstract description 10
- 230000002787 reinforcement Effects 0.000 claims description 33
- 239000000463 material Substances 0.000 claims description 21
- 230000003313 weakening effect Effects 0.000 claims description 16
- 239000004033 plastic Substances 0.000 claims description 11
- 229920003023 plastic Polymers 0.000 claims description 11
- 238000003825 pressing Methods 0.000 claims description 10
- 229920001169 thermoplastic Polymers 0.000 claims description 2
- 239000004416 thermosoftening plastic Substances 0.000 claims description 2
- 238000005728 strengthening Methods 0.000 claims 2
- 239000000470 constituent Substances 0.000 claims 1
- 238000002360 preparation method Methods 0.000 claims 1
- 230000003014 reinforcing effect Effects 0.000 abstract description 7
- 239000006260 foam Substances 0.000 abstract description 5
- 230000007704 transition Effects 0.000 description 9
- 239000002023 wood Substances 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 230000018109 developmental process Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000002666 chemical blowing agent Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B5/00—Joining sheets or plates, e.g. panels, to one another or to strips or bars parallel to them
- F16B5/02—Joining sheets or plates, e.g. panels, to one another or to strips or bars parallel to them by means of fastening members using screw-thread
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R13/00—Elements for body-finishing, identifying, or decorating; Arrangements or adaptations for advertising purposes
- B60R13/02—Internal Trim mouldings ; Internal Ledges; Wall liners for passenger compartments; Roof liners
- B60R13/0206—Arrangements of fasteners and clips specially adapted for attaching inner vehicle liners or mouldings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B25/00—Screws that cut thread in the body into which they are screwed, e.g. wood screws
- F16B25/0036—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw
- F16B25/0042—Screws that cut thread in the body into which they are screwed, e.g. wood screws characterised by geometric details of the screw characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B29/00—Screwed connection with deformation of nut or auxiliary member while fastening
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Connection Of Plates (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
The component (1) according to the invention has a screw stud (2) for receiving a screw (3), wherein the screw stud (2) typically projects from the component (1) and is connected in one piece with the component (1). This screw post (2) has a hollow space (5) surrounded by a wall (4), said hollow space (5) being open towards an introduction side (6) of the screw (3). The screw post (2) has reinforcing portions (7), between which reinforcing portions (7) there are local weakened portions (8) of the wall (4). The wall (4) of the screw shank (2) is made easily yielding by this weakened section (8) and can be pressed. The wall (4) is therefore significantly thinner than a conventional screw cylinder and can therefore yield. Thus, non-self-tapping screws for foam injection moldings can also be used for compact injection moldings.
Description
Technical Field
The invention relates to a component with a screw stud, a screw connection and a method for connecting one component to another component by means of a screw, wherein the component is produced in a compact injection molding method. The component can be used in particular as an interior trim part in the manufacture of motor vehicles.
Background
Plastics are used in many industrial fields, for example in the automotive industry, in particular for interior components, such as instrument panels, center consoles and door trims, in particular because of their high strength and low weight. For the detachable connection of plastic parts, screw connections are used, for which in particular requirements are made with regard to the screwability which can be repeated. The screws used in the compact injection-molded parts are self-tapping screws, which therefore have sharp edges on the thread path, so that they can sink and tap the thread at this point when they are screwed into the compact injection-molded parts.
Such screws are known as self-forming screws or self-tapping screws, which may be classified in a subclass of "wood screws". The screw basically comprises a head and a screw core which is designed as an elongated cone or cone and which is more or less tapered on the screw tip. The screw core is surrounded by a helically running thread course (cutting flank) which projects radially from a thread base which transitions with a more or less sharp bend into the two flanks of the cutting thread. The flanks are in turn provided with a constant slope from the thread base up to the flank tip, so that a constant flank angle is obtained between the two flanks.
Furthermore, the competition in the automotive industry for lightweight structures has led to an increasingly widespread use of plastics, with physical or chemical foams also being increasingly used, i.e. by air (nitrogen, CO)2) Instead of a plastic material. In the case of physical foams, according toOr similar methods, such as injecting nitrogen, carbon dioxide or chemical blowing agents into the plastic melt under pressure in a transcritical state during plasticizing and uniformly distributing them. After the injection in pressureless form, the gas separates again from the melt and forms a fine foam structure. Removal of post-pressure and reduced tack, minimizing or eliminating sag positions and warping are significant aspects that accentuate this trend.
Since self-tapping screws, when used with foamed plastic, have the disadvantage of damaging the plastic during screwing in, for example as a result of cracks in the screwed-in eye or as a result of stress crack formation, special screws have been developed for this application, see DE 102014114165, DE 102015103015 or DE 102016120728. These screws have a blunt edged thread path and squeeze material rather than tap threads. In the case of screw connections using such screws, damage to the compact layer, i.e. to the outer skin of the screw cylinder of the component, no longer occurs in the MuCell injection molded part.
However, this new screw cannot be used with typical compact injection-molded parts, since in the case of compact injection-molded parts, material pressing cannot be achieved due to the compactness of the material. The screw stud of the compact injection molded part is dimensioned thick enough to be able to tap the thread therein. However, when the screw does not fit into the tapped thread but deviates from it, the classic wood screw presents problems in terms of repeatable screwability (often several tens of times the screw is screwed into the same screw post repeatedly).
Disclosure of Invention
The object of the invention is therefore to overcome the disadvantages of the prior art in the screwing of compact injection-molded parts by using means which are constructively as simple as possible.
This technical problem is solved by the subject matter of the independent claims. Advantageous developments of the invention are given in the dependent claims, the description and the drawings.
The component according to the invention has a screw stud for receiving a screw, wherein the screw stud typically projects from the component and is connected to the component in one piece. This screw stud has a hollow space surrounded by a wall, said hollow space opening towards the lead-in side of the screw. In this regard, the screw post of the present invention is equivalent to a conventional screw post. The novelty is that the stud has at least two reinforced portions with a locally weakened portion of the wall between the reinforced portions. The wall of the screw post becomes easily yieldable by this weakened portion and can be pressed.
This reinforcement has only a mechanical task, so that it can be implemented as a short support projecting from the wall with minimal material costs. The length of the reinforcement part is less than twice the outer diameter of the screw post, in particular less than one time the outer diameter of the screw post. This reinforcement does not alternate with a large-area heat-dissipating structure, which may also be present in conventional screw studs, and whose function is merely to facilitate cooling after injection molding and to lead to short cycle times during injection molding.
It is also advantageous if the reinforcement has the shape of a hollow cylindrical section with walls narrowing to the introduction side. In the transition to the remaining structure of the component, the reinforcement is slightly wider than behind the screw eye and can therefore better guide the force during the screw connection.
A further advantageous development of the invention provides that 20% to 80%, in particular 30% to 70%, of the wall has a local weakening. In this way, a good balance is achieved between sufficient strength of the structure for repeated screw connections and at the same time a low required screwing force.
It has been shown that the wall thickness of the wall in the region of the local weakening is related to the diameter of the screw as follows:
for screws having a diameter of 2mm to 4mm, the wall thickness is 0.4mm to 1.0mm,
the wall thickness is 0.6mm to 1.5mm for screws having a diameter >4mm and ≦ 8mm, and 0.8mm to 2.5mm for screws having a diameter >8mm and ≦ 16 mm.
The wall is therefore significantly thinner than a conventional screw stud and can therefore yield. In this way, non-self-tapping screws for foam injection moldings can also be used for compact injection moldings. This screw therefore presses the screw shank in the region of the weakened portion of the wall, thus ensuring a significantly improved repeatable screwability. The reinforcement between the weakened portions gives the screw cylinder the necessary stability and ensures the return force of the wall when the screw is unscrewed again.
According to an advantageous development of the invention, the screw cylinder is rotationally symmetrical. The local weakening of the wall is advantageously on the outside of the wall. Thus, a uniform inner side of the wall is provided for the screw and screwing in is facilitated.
The insertion of the screw into the screw cylinder is advantageously facilitated by the feature that the screw cylinder exhibits a cylindrical wall with a lead-in chamfer on the inside of the wall. In this way, the torque required for the first rotation of the screw before the screw is stabilized is lower. It has proven advantageous if the screw shank is conical on the inside of the wall and widens at an inclination toward the opening of the introduction side at an angle of between 0.5 ° and 10 °, in particular between 3 ° and 8 °, to the vertical. In this angular range, the screw can be screwed in particularly easily, while at the same time it can then be seated well.
In terms of the configuration of the reinforcement, it is advantageous to provide at least three reinforcements, preferably at least four, six, eight or ten reinforcements. These reinforcements are separated from each other by weakened portions of the wall, respectively. A uniform spacing is preferred. In this way, a good balance between the yield of the weakened wall and the stability under high loads is ensured.
In an additional design variant of the screw column, at least one part of the reinforcements are not only interconnected by the wall, but additionally by a second wall of the screw column. This second outer wall, which may also have an annular and/or rotationally symmetrical character, is used as an additional reinforcement. Advantageously, the wall thickness of the second wall is between 1.6mm and 3mm, in particular between 1.8mm and 2.5 mm. This wall thickness leads to sufficient reinforcement with as low a material usage as possible. It is furthermore advantageous to make the wall thickness of the second wall greater than the wall thickness of said wall. The wall in contact with the screw can thus be kept thin and easily yielding, with the second wall being responsible for the high stability.
The length of the reinforcement perpendicular to the wall is advantageously greater than the wall thickness of the wall in the region with the local weakening. The wall can thus yield sufficiently without hitting the second wall located behind. It has been found to be advantageous if the width of the reinforcement parallel to the wall is from 0.7mm to 4mm, in particular from 1mm to 2.5 mm.
Although the low gas content is also harmless in the screw cylinder, it is advantageous if the component is made of a non-foamed plastic and is produced by compact injection molding without gas content.
The screw connection according to the invention is based on the component according to the invention with the screw stud and the component is connected to the other component by means of a screw, wherein the screw can be screwed in by pressing the material of the screw stud. This screw therefore does not tap a thread in the screw shank, but presses against the material of the wall, which pressing is facilitated by the weakened region. As explained above, this screw connection has a significantly improved screwability and meets the requirements of the automotive industry.
Advantageously, the thread of the screw has a rounded edge at least in sections, in particular spaced from the tip of the screw, and thus prevents tearing of the inner side surface of the screw shank. It is particularly advantageous if the thread path of the screw has a flank angle of 30 ° to 90 °, preferably > 60 ° or 70 °, measured from the edge tip to the base of the screw. This results in a blunt shape, in which the angle can be changed on the side edges.
The blunt screw thread course and the rounded transition between the flank and the thread base determine a non-notched screw profile, which leads to a further stress reduction of the plastic or foam material. The transition between the flank and the thread base can advantageously be made stepwise, wherein the external thread region as a first section has a non-sharp flank angle of 30 ° to 90 °, preferably a flank angle of > 60 ° or 70 °. The second section in the transition between the flank and the thread base is a tangential transition having an angle of 145 ° to 170 °. The third segment includes a thread base between two flanks and is a circular segment with an angle of 170 ° to 180 °.
The edge of the thread path of the screw is preferably rounded, in particular at a distance from the screw tip. The cutting of the material also always means a weakening of the material at the cut edge. The rounded edges prevent the screw from cutting into the material. Alternatively, the screw is screwed into the material by pressing and compressing.
When the ratio of the height of the thread path of the screw to its width is less than 1, in particular less than 2, a careful pressing of the material of the screw shank takes place.
According to a further advantageous development of the invention, the screw has a tip for piercing the screw shank on the base. At this point the thread is not rounded but forms a point or has sharp edges. The screw thread at this point can also be designed as a thread-cutting thread in order to make possible a better penetration into the base of the screw cylinder. Alternatively, the screw can also be dimensioned in comparison to the screw cylinder such that the screw has a blunt tip which clamps on the bottom of the screw cylinder when screwed in. The clamping force of the screw in the screw cylinder in the end state is increased by the screw being additionally pressed into the thread path produced in the screw cylinder by the pressing when the tip is placed on the bottom of the screw cylinder.
Preferably, the pitch (thread lift) of the thread line is changed. The change in thread lift means that the distance between adjacent thread windings is not constant. By changing the thread lift, the material is shortened or lengthened during screwing. This additional material tensioning using screws improves the strength of the connection. If the pitch increases towards the screw tip, higher friction or higher torque occurs at the end of the screwing process, at which time the area increases due to the smaller pitch.
A good screwing action can be ensured when the pitch of the screw is greater than 1.5mm, in particular greater than 2 mm. There is thus sufficient space for the screw shank material between the threads to tear as little material as possible between the two threads. Nevertheless, the screw has a secure seating.
It is also advantageous if the contour of the thread path of the screw changes in its geometry, in particular the edge angle (Kantigkeit) of the thread path of the screw increases toward the head of the screw. The torque at the start of unscrewing is kept high by the increased edge degree near the screw head.
Screws with an outer diameter of 4mm to 6mm and a length of 12mm to 20mm have proven to be advantageous for the screw connection according to the invention.
The method for connecting a component with the novel screw post with another component through a screw comprises the following steps:
forming a component with a screw stud from a thermoplastic in a compact injection molding process,
providing a screw having a plurality of blunt-edged screw threads and an outer diameter at least partially greater than an inner diameter of the screw post,
another component is placed against the screw post,
screwing the screw through the further component into the screw stud in a non self-tapping manner, wherein the screw is screwed in by pressing the material of the screw stud.
Screws with non-self-tapping threads and conventional tools can thus be used for compact injection-molded parts without matching, with torques similar to the wood screws used up to now, without problems due to deformation even when the parts are frequently screwed repeatedly.
Drawings
Advantageous embodiments according to the invention are explained below by referring to the figures. The figures are as follows:
figure 1 shows a screw stud of a component according to the prior art,
figure 2 shows a first embodiment of a screw stud of a component according to the invention,
figure 3 shows a second embodiment of a screw post of a component according to the invention,
FIG. 4 shows a screw for screw connection according to the invention, and
fig. 5 shows a screw connection.
The figures are only schematic representations and are only intended to explain the invention. Identical or functionally identical elements are denoted by the same reference numerals throughout.
Detailed Description
Up to now, the constructional provisions as in fig. 1 have been followed for the component 1 with the screw stud 2. The stud 2 projects from the part 1 and has a height H which is substantially equal to two to five times the thickness S of the part 1. The stud 2 is formed in one piece with the part 1. At the connection point between the component 1 and the screw stud 2, the outer diameter D of the screw stud 2 is approximately twice the outer diameter of the screwing aid D, which can then receive the material cut by the screw 3 when tapping the thread. The inner diameter d of the screw post 2 is significantly smaller. The wall thickness of the screw post 2 is equal to approximately the inner diameter d of the screw post 2. At said transition between the screw stud 2 and the remaining part 1, the radius R is approximately a quarter of the thickness S of the remaining part 1 at this location.
This solid screw stud 2 is suitable for so-called wood screws, which have to be sunk into this screw stud 2 in a self-tapping manner. By means of the large wall thickness of the screw stud 2, the screw stud 2 is sufficiently stable and can intercept large screwing forces. For the purpose of facilitating the screwing in, the screw cylinder 2 is slightly tapered, wherein the inner wall of the screw cylinder 2 has an angle a not specifically defined with the vertical. This prevents a significant increase in the torque required for screwing in.
This screw post 2 is however not suitable for the use of a screw 3 as explained later on with reference to fig. 4.
The component 1 according to the invention, in particular the screw stud 2 thereof, is explained with reference to fig. 2 and 3.
A first variant of a screw post 2 according to the invention according to fig. 2 comprises a wall 4, said wall 4 extending around a hollow space 5. This wall 4 of the screw cylinder 2 is conical in relation to the inner side 4i and has a slope similar to that shown in fig. 1 toward the opening 10 for the introduction side 6 of the screw 3, but the angle a from the vertical is specified here to be 3 ° to 8 °. Smaller or larger angles a in the range from 0.5 ° to 10 ° are also possible.
The screw post 2 is rotationally symmetrical, wherein the wall 4 has a plurality of local weakenings 8 on the outer side 4 a. In fig. 2, eight local weakened portions 8 are separated by a reinforcing portion 7. These reinforcements 7 project perpendicularly from the wall 4 and have a length 7l and a width 7d as will be explained below.
When the wall thickness 4s of the wall 4 is dimensioned in the region of the local weakening 8, the following dimensioning has proved to be suitable for different screw dimensions:
for screws 3 with a diameter d1 of from 2mm to 4mm, the wall thickness 4s is 0.4mm to 1 mm; for screws 3 with a diameter d1 of from 4mm to 8mm, the wall thickness 4s is 0.6mm to 1.5 mm; and for screws 3 with a diameter d1 of from 8mm to 16mm, the wall thickness 4s is 0.8mm to 2.5 mm. The wall thickness 4s in the region of the local weakening 8 is significantly smaller than in the case of the classic screw stud 2 corresponding to fig. 1, compared to the pressing force of the screw which increases with increasing size of the screw.
The dimensions of the reinforcement 7 relate to the respective wall thickness 4s according to the dimensions of the screw stud 2. The length 7l of the reinforcement 7 perpendicular to the wall 4 is greater than the wall thickness 4s of the wall 4 in the region of the local weakening 8. The width 7b of the reinforcing portion 7 parallel to the wall 4 is 0.7mm to 4 mm. The width 7b of the reinforcement 7 here decreases with increasing distance from the wall 4. The screw stud 2 and the component 1 are produced according to a compact injection molding method as in the case of the component 1 according to fig. 1, i.e. the component 1 contains no or only a low to negligible amount of gas components.
According to the embodiment corresponding to fig. 2, the number of reinforcements 7 is eight, but screw columns 2 with two, four, six, eight or ten reinforcements are also possible. An odd number of intensification sections 7 is also conceivable within this range.
In the alternative embodiment according to fig. 3, only four reinforcements 7 are provided. Here, the wall 4 of the screw cylinder 2 also extends around a hollow space 5, which hollow space 5 opens in the direction of introduction 6 of the screw 3 and widens. These four reinforcements 7 with length 7l and width 7b connect the wall 4 with the second wall 11. According to fig. 3, this second wall 11 completely surrounds the wall 4. It is also conceivable, however, to provide the second wall 11 with a plurality of interruptions. According to fig. 3, the wall thickness 11s of this second wall 11 is here greater than the wall thickness 4s of the wall 4 connected to the hollow space 5. The second wall 11 has a second wall thickness 11s of between 1.6mm and 3 mm. The second wall 11 ensures additional stability for the wall 4, whereby the wall 4 can be designed as a thin and easily yielding wall in the region of the local weakening 8. Here, the reinforcement 7 can also be designed to be shorter and narrower than in the embodiment according to fig. 3.
Fig. 4 shows a screw 3 according to the invention for screw connection. The outer shape of the screw 3 may be cylindrical or conical, for example. A typical outer diameter d1 of the screw 3 is 4mm to 6mm, particularly advantageously the following dimensions: 4mm, 4.5mm, 5mm, 5.5mm or 6 mm. The length L is 12mm to 35mm and matches the height H of the screw post 2.
The screw 3 has a blunt thread 31, said thread 31 extending in a helical fashion around the shank of the screw 3. The screw 3 has rounded thread valleys and blunt thread tips so that the thread lines of the screw 3 do not tear the wall 4 of the post 2 but ensure that the wall 4 of the post 2 fits well during the screwing-in process due to plastic deformation and friction without being cut. The wall 4 is not cut but only squeezed so that the "thread" can be restored again after the screw 3 has been unscrewed. Crack formation or cracking of the screw post 2 is avoided. This is also determined by the fact that the flanks of the thread run are at an obtuse angle, here an angle of 80 °, along the angle w. The side edge angle w is therefore in the range of more than 30 ° to 90 °, in particular about 60 ° or 70 °.
The transition between the flank of the thread path and the thread bottom is a step-by-step transition. The thread tip is rounded. The pitch 33 of the screw 3 is greater than that of a wood screw of the same diameter, where the pitch is at a distance of 2.09mm, which should be at least about 1.5mm, in particular about 2 mm. The pitch 33 and the geometry of the screw thread path are uniform here. Alternatively, the pitch 33 and the geometry of the screw thread may also vary, in particular the edge length of the screw thread 31 may increase towards the screw head 31.
The compressibility of the screw 3 is emphasized by the fact that the ratio of the height h of the screw thread 31 of the screw 3 to its width b is less than 1, i.e. the thread 31 is considerably wider at the same height h than in the case of wood screws.
Fig. 5 shows the screw post 2 of the component 1 after the screw 3 has been screwed in. The further component 20 is placed on the screw post 2 and connected to the component 1 as a screw connection. The screw stud 2 with the lead-in chamfer 9 has a height H from its opening 10 to its bottom. The opening 10 is here larger than the inner diameter 4i (measured approximately at half the height H) of the screw post 2. This is achieved here by an opening angle a which, as explained above, is in the range from 3 ° to 8 °.
The screw 3 in fig. 4 has a length L here, which with its tip 32 penetrates into the bottom of the screw shaft 2. The screw 3 has for this purpose a threaded tip 32. Alternative embodiments provide for shorter screws 3, but always slightly longer than the height H of the screw post 2. During screwing, this screw 3 is clamped to the bottom of the screw cylinder 2. That is, the screw 3 may be blunt and need not pierce the bottom. Nevertheless, the torque at the end of screwing-in increases due to clamping.
List of reference numerals
1 part
2 screw column
3 screw
4 wall
Outside of the 4a wall
Inside of 4i wall
Wall thickness of 4s wall
5 hollow space
6 introduction side
7 reinforcing part
7b width of the reinforcing part
7l length of the reinforcing portion
8 weakened part
9 lead-in chamfer
10 opening
11 second wall
Wall thickness of 11s second wall
20 another part
31 screw thread line
32 tip
33 pitch of thread
angle of a screw column
Half outer diameter of D screw column
Inner diameter of d screw column
diameter of d1 screw
Side angle of thread line of w screw
b width of the thread line of the screw
h height of screw thread line
Height of H screw column
Length of L-shaped screw
Radius of connecting part of R screw column
Thickness of s-part
Claims (31)
1. A component (1) with a screw stud (2) for receiving a screw (3), wherein the screw stud (2):
is an integral part of the component (1), and
having a hollow space (5) surrounded by a wall (4), the hollow space (5) being open towards an introduction side (6) of the screw (3),
it is characterized in that the preparation method is characterized in that,
the screw stud (2) having at least two reinforcements (7), the reinforcements (7) projecting from the wall (4) and between the reinforcements (7) there being local weakenings (8) of the wall (4),
at least one part of the reinforcement (7) is connected to one another by a second wall (11) of the screw post (2), wherein the wall (4) can yield sufficiently without touching the second wall (11) lying behind.
2. Component (1) according to claim 1, characterized in that the length (7 l) of the reinforcement (7) is less than twice the outer diameter of the stud (2).
3. Component (1) according to claim 1, characterized in that the length (7 l) of the reinforcement (7) is less than one outer diameter of the screw stud (2).
4. Component (1) according to any one of claims 1 to 3, characterized in that the reinforcement (7) has the shape of a hollow cylindrical portion with walls (4) narrowing towards the introduction side (6).
5. Component (1) according to any one of claims 1 to 3, characterized in that 20% to 80% of the wall (4) has a local weakening (8).
6. Component (1) according to any one of claims 1 to 3, characterized in that 30% to 70% of the wall (4) has a local weakening (8).
7. Component (1) according to any one of claims 1 to 3, characterized in that the wall thickness (4 s) of the wall (4) with the local weakening (8) is:
for said screw (3) with a diameter of 2mm to 4mm, 0.4mm to 1.0mm,
for the screw (3) with a diameter >4mm and ≦ 8mm, 0.6mm to 1.5mm,
and is
For the screw (3) with a diameter >8mm and ≦ 16mm, 0.8mm to 2.5 mm.
8. Component (1) according to any one of claims 1 to 3, characterized in that the stud (2) is rotationally symmetrical and the local weakening (8) is on the outside (4 a) of the wall (4).
9. Component (1) according to any one of claims 1 to 3, characterized in that the inner side (4 i) of the screw stud (2) with respect to the wall (4) is cylindrical with a lead-in chamfer (9).
10. Component (1) according to one of claims 1 to 3, characterized in that the screw stud (2) is designed conical with respect to the inner side (4 i) of the wall (4) and widens towards the opening (10) of the introduction side (6) with a slope at an angle of between 0.5 ° and 10 ° to the vertical.
11. Component (1) according to one of claims 1 to 3, characterized in that the screw stud (2) is designed conical with respect to the inner side (4 i) of the wall (4) and widens towards the opening (10) of the introduction side (6) with a slope at an angle (a) of between 3 ° and 8 ° to the vertical.
12. A component (1) according to any one of claims 1-3, characterised in that at least three said strengthening portions (7) are provided.
13. A component (1) according to any one of claims 1-3, characterised in that four, six, eight or ten strengthening portions (7) are provided.
14. Component (1) according to claim 8, characterized in that the wall thickness (11 s) of the second wall (11) is 1.6 to 3 mm.
15. Component (1) according to claim 8, characterized in that the wall thickness (11 s) of the second wall (11) is greater than the wall thickness (4 s) of the wall (4).
16. Component (1) according to any one of claims 1 to 3, characterized in that the length (7 l) of the reinforcement (7) perpendicular to the wall (4) is greater than the wall thickness (4 s) of the wall (4) in the region with the local weakening (8).
17. Component (1) according to any one of claims 1 to 3, characterized in that the width (7 b) of the reinforcement (7) parallel to the wall (4) is 0.7mm to 4 mm.
18. Component (1) according to one of claims 1 to 3, characterized in that the component (1) is made of plastic without gaseous constituents by compact injection molding.
19. Screw connection with a component (1) according to one of claims 1 to 3, a further component (20) and a screw (3) for fixing the component (1) with the further component (20), wherein the screw (3) can be screwed in by pressing the material of the screw stud.
20. A screw connection according to claim 19, characterized in that the screw thread (31) of the screw (3) has an at least partially rounded edge.
21. A screw connection according to claim 19, characterized in that the screw thread (31) of the screw (3) has at least partly a rounded edge spaced from the tip (32) of the screw (3).
22. A screw connection according to claim 19, wherein the screw thread (31) of the screw (3) has a flank angle (w) of 30 ° to 90 °.
23. A screw connection according to claim 19, characterised in that the screw thread line (31) of the screw (3) has a flank angle (w) of > 60 °.
24. A screw connection according to claim 19, wherein the screw thread (31) of the screw (3) has a flank angle (w) of >70 °.
25. A screw connection according to claim 20, wherein the pitch (33) of the screw (3) is greater than 1.5 mm.
26. A screw connection according to claim 20, wherein the pitch (33) of the screw (3) is greater than 2 mm.
27. Screw connection according to one of claims 19 to 26, characterized in that the screw thread (31) of the screw (3) varies in its geometry.
28. A screw connection according to claim 27, characterised in that the edge of the screw thread (31) of the screw (3) increases towards the head of the screw.
29. Screw connection according to one of claims 19 to 26, characterized in that the screw (3) has an outer diameter (d 1) of 4 to 6mm and a length (L) of 12 to 20 mm.
30. Screw connection according to one of claims 19 to 26, characterised in that the ratio of the height (h) of the screw thread path (31) of the screw (3) to its width (b) is less than 1.
31. Method for connecting a component (1) according to any one of claims 1 to 18 with another component (20) by means of a screw (3), comprising the steps of:
-forming the component (1) with the screw stud (2) from a thermoplastic in a compact injection molding process,
-providing the screw (3), the screw (3) having a plurality of blunt-edged screw threads (31) and an outer diameter (d 1) which is at least partially larger than the inner diameter (d) of the screw post (2),
-resting the further component (20) on the screw post (2),
-screwing the screw (3) through the further component (20) into the screw post (2) in a non self-tapping manner, wherein the screw (3) is screwed by pressing the material of the screw post (2).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102017104384.5A DE102017104384B4 (en) | 2017-03-02 | 2017-03-02 | COMPONENT WITH SCREW DOME AND METHOD FOR CONNECTING A COMPONENT |
DE102017104384.5 | 2017-03-02 | ||
PCT/DE2018/200019 WO2018157894A1 (en) | 2017-03-02 | 2018-02-27 | Component comprising screw boss and method for connecting a component |
Publications (2)
Publication Number | Publication Date |
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CN110730872A CN110730872A (en) | 2020-01-24 |
CN110730872B true CN110730872B (en) | 2022-02-25 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CN201880015424.1A Active CN110730872B (en) | 2017-03-02 | 2018-02-27 | Component with screw stud and method for connecting components |
Country Status (3)
Country | Link |
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CN (1) | CN110730872B (en) |
DE (1) | DE102017104384B4 (en) |
WO (1) | WO2018157894A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US11078948B2 (en) | 2019-02-18 | 2021-08-03 | Ford Global Technologies, Llc | Fastener boss and motor vehicle component incorporating that fastener boss |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE8226885U1 (en) * | 1982-09-24 | 1986-01-02 | Eberhard Jaeger Gmbh & Co Kg, 5928 Laasphe | Self-tapping screw |
DE19944589A1 (en) * | 1999-09-16 | 2001-03-22 | Ejot Verbindungstech Gmbh & Co | Screw connection |
DE10350887A1 (en) | 2003-10-31 | 2005-05-25 | Man Nutzfahrzeuge Ag | Component fitting and method for producing a screw dome |
DE102006016032A1 (en) | 2006-04-05 | 2007-10-18 | Lisa Dräxlmaier GmbH | Aerofoil cathedral e.g. screw cathedral, has elongated mounting part, where rib with curved cross section integrally extends from mounting part and is fastened to mounting part in tangential manner |
CN202484039U (en) * | 2012-02-13 | 2012-10-10 | 美迪希实验仪器(上海)有限公司 | Integral stud molding structure |
CN103470602B (en) * | 2012-06-07 | 2015-06-03 | 纬创资通股份有限公司 | Stud |
DE202013100351U1 (en) | 2013-01-25 | 2013-01-30 | Vorwerk & Co. Interholding Gmbh | Screw-connected parts as well as screw set |
DE102014004306A1 (en) * | 2014-03-26 | 2015-10-01 | Elringklinger Ag | Plastic fastener with self-tapping and locking thread for components |
DE202014103640U1 (en) * | 2014-08-05 | 2014-08-21 | Smp Deutschland Gmbh | Screw dome for attaching a component |
DE102014114165B4 (en) | 2014-09-30 | 2022-11-10 | Lisa Dräxlmaier GmbH | SCREW CONNECTION FOR COMPONENT MADE OF THERMOPLASTIC PLASTIC |
DE102015103015A1 (en) | 2015-03-03 | 2016-09-08 | Lisa Dräxlmaier GmbH | Screw for foamed plastics |
-
2017
- 2017-03-02 DE DE102017104384.5A patent/DE102017104384B4/en active Active
-
2018
- 2018-02-27 WO PCT/DE2018/200019 patent/WO2018157894A1/en active Application Filing
- 2018-02-27 CN CN201880015424.1A patent/CN110730872B/en active Active
Also Published As
Publication number | Publication date |
---|---|
DE102017104384A1 (en) | 2018-09-06 |
WO2018157894A9 (en) | 2019-01-17 |
DE102017104384B4 (en) | 2024-01-25 |
WO2018157894A1 (en) | 2018-09-07 |
CN110730872A (en) | 2020-01-24 |
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