Link chain with optimized link shape

Abstract

Link chain with alternating inner links (1) and outer links connected to each other by means of a chain joint, each having two openings (2) with a center distance of the division (T), characterized in that the transition area (6) between at least the back (3) and an end face (5) of an inner link (1) and / or an outer link has an outer contour such that three tangents (T1, T2, T3) can be applied to this contour, which satisfy the following conditions: that a) the first tangent (T1) with the point of contact nearest to the front face (5) intersects a parallel (P1) touching the back (3) to the midline (M) passing through the centers of the two openings (2) mentioned above at an angle α, b) the second tangent (T2) with the point of tangency second nearest to the end face (5) intersects the aforementioned parallel (P1) at an angle α / 2, c) the third tangent (T3) intersects the aforementioned parallel (P1) at an angle α / 4 with the point of tangency third closest to the end face (5), d) the distance (A 2-3 ) between the points of intersection of the second and third tangent (T2, T3) with the aforementioned parallel (P1) the distance (A 1-2 ) between the intersection points of the first and second tangent (T1, T2) with the aforementioned parallel (P1) multiplied by the factor cos(α / 2), and e) the angle α in a) to d) is in the range of 40° to 50° and the factor in d) has a value in the range of cos 20° to cos 25°.

Description

[0001] The invention relates to a link chain with alternating inner and outer links connected to one another by means of a chain joint, each of which has two openings with a center-to-center distance of the pitch T.

[0002] Plate-link chains come in a wide variety of shapes and designs. Examples are described in DE 12 27 288 A, DE 28 14 587 A1, DE 10 2006 017 121 A1 and US 2 038 583 A. In addition to inner links arranged directly on the chain pins, widely used chain designs include bushing chains and roller chains. In a bushing chain, an inner link usually consists of two inner links arranged parallel to one another and two bushes connecting them. The bushes are pressed into corresponding openings in the inner links. The outer link usually consists of two outer links arranged parallel to one another and two chain pins connecting them. To form a chain joint, a chain pin of the outer chain link extends through the opening of a bush of the adjacent inner link.In many applications, a tapered shape of the outer and inner plates has become established. The end areas of the plates are usually rounded to ensure a substantially uniform material thickness around the largest possible circumference of the openings in the inner and outer plates, at least at the end areas. Link-link chains are available in a wide variety of sizes, with the largest chain designs, with the large pitches T, being particularly common in conveyor technology. In addition to breaking strength, the fatigue strength of the link-link chain naturally plays a significant role in link-link chains. Improvements are being sought, particularly with regard to this fatigue strength.

[0003] It is therefore the object of the present invention to improve a plate chain of the type mentioned at the outset with regard to its fatigue strength.

[0004] For this purpose, in a plate-link chain of the type mentioned at the outset, it is provided according to the invention that the transition area between at least the back and one end face of an inner plate and / or an outer plate has an outer contour such that three tangents can be applied to this outer contour, which satisfy the following conditions: that a) the first tangent with the point of contact closest to the front side intersects a parallel line touching the back to the center line passing through the centers of the two openings mentioned at an angle α, b) the second tangent with the second closest point of contact to the front side intersects the said parallel at an angle α / 2, c) the third tangent with the third closest point of contact to the end face intersects the said parallel at an angle α / 4, (d) the distance between the points of intersection of the second and third tangents with the said parallel is equal to the distance between the points of intersection of the first and second tangents with the said parallel multiplied by the factor cos(α / 2), and c) the angle α in a) to d) is in the range from 40° to 50°, preferably 42.5° to 47.5°, and the factor in d) has a value in the range from cos 20° to cos 25°, preferably cos 22° to cos 23°.

[0005] The coupling to angle α mentioned in points a) to d) is specified in c) with an individual tolerance for a), b), c), and / or d). Within this tolerance, however, a significant improvement in both the breaking strength of the link chain and its fatigue strength is still achieved. The resulting shape leads to a more optimal stress distribution in the inner or outer link plate.

[0006] In the transition area, the tab is given an outer contour that deviates from a standard tab shape; in particular, the idea of ​​a material thickness distribution that is as uniform as possible on the end area side of the respective opening is abandoned.

[0007] An optimum can be achieved in particular if, in an embodiment, α has the value of 45° and the factor in d) has a value of cos 22.5°.

[0008] Furthermore, it can be provided that the first tangent intersects a perpendicular touching the end face to the center line running through the centers of said opening at a distance from the center line that corresponds to 0.16 to 0.26 times, preferably 0.2 to 0.22 times, and more preferably 0.205 to 0.215 times the pitch T. Depending on the design of the end face, this perpendicular will be a tangent to the end face that runs at right angles to the center line and thus indicates the greatest length of the associated outer link or inner link. Furthermore, this intersection point specifies a significant starting point for the creation of the outer contour, which significantly influences the further course of the outer contour.

[0009] According to one variant, the contour of the transition area can preferably have both straight and curved sections. The tangent design only specifies the essential parameters of the outer contour and, if strictly followed, would result in a relatively angular tab shape. Of course, the entire contour can be rounded or rounded while maintaining the design principle.

[0010] Advantageously, the outer contour of the transition region comprises both straight and curved regions, so that the contact points of the tangents each lie in a straight region of the outer contour of the transition region and the straight regions are connected to one another by means of, preferably convex, curved regions.

[0011] The front end can also be rounded accordingly and doesn't necessarily have to be straight. Therefore, another variant provides for the straight section closest to the front end, with the point of contact for the first tangent, to transition into the front end via a convexly curved section. In extreme cases, this results in virtually no front end remaining, and the entire front area is curved.

[0012] Furthermore, the invention relates to a link chain with inner links and outer links which are alternately connected to one another by means of a chain joint and which each have two openings with the pitch T, wherein at least the back of the inner link and / or the outer link has a substantially central concave-shaped recess.

[0013] In such a generic link chain, the fatigue strength is increased in the same way by the fact that the recess has an outer contour on at least one side to a perpendicular intersecting the base of the recess to the center line passing through the centers of the opening such that three tangents can be applied to this outer contour, which meet the following conditions: that a) the first tangent with the point of contact furthest from the said perpendicular intersects a parallel line touching the bottom of the recess to the centre line passing through the centres of the two said openings at an angle α, b) the second tangent with the point of contact second furthest from the said perpendicular intersects the said parallel at an angle α / 2, c) the third tangent with the third furthest point of contact from the said perpendicular intersects the said parallel at an angle α / 2, (d) the distance between the points of intersection of the second and third tangents with the said parallel is equal to the distance between the points of intersection of the first and second tangents with the said parallel multiplied by the factor cos(α / 2), and c) the angle α in a) to d) is in the range from 40° to 50°, preferably 42.5° to 47.5°, and the factor in d) has a value in the range from cos 20° to cos 25°, preferably cos 22° to cos 23°.

[0014] Here, too, c) is intended to break the dependency of a) to d) in the form of a comprehensive tolerance, so that a different value for α (selected from c)) can be applied in a) to d). This is intended to specify a permissible tolerance.

[0015] The concave recess has the specified outer contour on at least one side. Concave is understood to mean wide. It can also be a series of straight sections. The outer contour specified according to the invention leads to an improvement in fatigue strength and a slight increase in breaking strength.

[0016] The recess can preferably have a relatively large dimension. Of course, this must not exceed a certain size. For this purpose, according to one variant, the largest width of the recess corresponds to at least four times, preferably at least 4.5 times, the greatest depth of the recess. However, the smallest width should also preferably correspond to at least three times the greatest depth of the recess.

[0017] According to one variant, the outer contour of the recess can have both straight and curved sections. Sharp corners, in particular, should be avoided, which can therefore be provided with transition radii.

[0018] A further embodiment provides that the contact points of the tangents each lie in a straight area of ​​the contour of the recess and the straight areas are connected to one another by means of, preferably concave, curved areas.

[0019] According to one variant, the point on the back with the greatest distance from the mentioned center line can preferably be arranged at a distance from the nearest end face that corresponds to at least 0.45 times, preferably 0.49 times, the pitch. In contrast to standard tab shapes, with this tab shape, the highest point of the back is positioned closer to the center of the tab and is no longer centered over the opening. This leads to a more even stress distribution.

[0020] Preferably, the aforementioned outer contours are not provided on just one side of the link plate. For this purpose, according to one embodiment, the inner and / or outer links have a symmetrical outer contour relative to the aforementioned centerline. This is in contrast to, for example, toothed links, which have a toothed shape on one side. If the new link plate shape is intended to replace the standard link plate shape, the aforementioned symmetrical outer contour is recommended.

[0021] Furthermore, the inner and / or outer plates can also have an outer contour symmetrical to the perpendicular mentioned in a). This ensures that the recess, if present, is centered and designed symmetrically to this center line.

[0022] A further increase in the fatigue strength can be achieved by making the inner and / or outer plates from a rolled sheet material, the rolling direction running parallel to the center line mentioned in a).

[0023] The rolling direction and stress distribution are thus coordinated and complement each other to advantageously increase the fatigue strength.

[0024] Furthermore, the invention relates to an inner link plate or outer link plate for a link-link chain according to one of claims 1 to 14, which is characterized in that the inner link plate or outer link plate fulfills both the specification for the inner link plate or the outer link plate from one of claims 1 to 6 and from one of claims 7 to 14. The link plate thus simultaneously has the specifications for the shape of the outer contour of the transition area and the specifications for the shape of the recess. Tests have shown that when these specifications are applied to all four transition areas and when used with two recesses, an increase in breaking force of approximately 3% and an increase in fatigue strength of approximately 20% could be achieved compared to a standard link plate shape with otherwise the same size and design.

[0025] An embodiment of the present invention is explained in more detail below with reference to the drawings. They show: Fig. 1 a front view of an inner flap according to the invention, Fig. 2 a representation of the geometric construction of a transition area of ​​the tab from Fig. 1, Fig. 3 a sketch of the geometric construction of the recess of the tab from Fig. 1, and Fig. 4 an inner flap according to the invention with a rounded outer contour.

[0026] The Fig. The inner link plate 1 shown in Figure 1 is a component of a bushed chain. The bushed chain comprises alternating inner links and outer links. Each outer link consists of two outer links arranged at a parallel distance from one another and two chain pins connecting them. Each inner link consists of two parallel inner links 1 and sleeves connecting them, which are pressed into the openings 2 of the inner link plate 1. The inner link plate 1 consists of a rolled and subsequently punched steel sheet, with the rolling direction running parallel to the center line M. The inner link plate 1 is both symmetrical to the center line M and symmetrical to a perpendicular S located exactly in the middle of the length of the inner link plate 1. M The inner plate 1 has a uniform thickness.

[0027] The inner link plate 1 has a spine 3 on the upper edge. Due to the symmetry, this is also present on the lower edge. The spines 3 each have a recess 4 arranged centrally therein, so that a straight section of the spine 3 is present on both sides of the recess 4. Furthermore, the inner link plate 1 each has straight end faces 5 at its ends. The center-to-center distance between the two openings 2 corresponds to the pitch T. Between the spine 3 and the end faces 5 there is a transition area 6 which gives the inner link plate 1 its decisive end contour. In the present case, each transition area 6 is formed by three straight areas 7, 8 and 9.

[0028] The recesses 4 are also formed by straight sections arranged in a row. Each half of the recess 4 has the three straight sections 10, 11, and 12. The two straight sections 12 meet in the area of ​​the vertical SM together and form the lowest point, the base G, of the recess 4. Due to the fact that the back 3 is straight and runs parallel to the center line M, the point of the back 3 with the greatest distance to the center line M extends over the said back 3. The distance A R of the back 3 from the front side 5 in the present embodiment is 0.5 times the pitch T (thus corresponding to at least 0.45 times, preferably 0.49 times the pitch T). Due to the symmetry, this applies to all transition areas 6. With a pitch of 19.05 mm, the distance A R = 9.525 mm.

[0029] Furthermore, the largest width B A the recess 4 in the present embodiment is 4.25 times the greatest depth T A the recess 4 (and thus at least 4 times the greatest depth T A ).

[0030] Based on the Fig. 2, the construction of a transition area 6 is explained in more detail. The straight area 7 is formed by a tangent T1, which runs at an angle α of 45° to a parallel P1. The parallel P1 runs parallel to the center line M. The parallel P1 touches the back 3 or forms a tangent to it. The tangent T1 is arranged such that it touches the front side 5 at a distance A M which corresponds to 0.2 times the pitch T (and thus 0.16 times to 0.26 times the pitch T). This specification precisely defines the course of the first straight section 7. The second straight section 8 results from a tangent T2, which runs at an angle α / 2 (22.5°) to the parallel P1. And the third straight section 9 results from a tangent T3, which intersects the parallel P1 at an angle α / 4 (11.25°). The intersection points with the parallel P1 of the individual tangents T1, T2 and T3 are chosen so that the distance A2-3 the intersection points of the second tangent T2 and T3 with the parallel P1 the distance A 1-2 the intersection points of tangents T1 and T2 with the parallel P1 multiplied by the factor cos(α / 2) (0.924). Based on these specifications, the exact course, i.e., the outer contour of transition area 6, is determined. This applies equally to all transition areas 6.

[0031] Based on the Fig. 3 the construction of the recess 4 is now explained in more detail.

[0032] Due to the symmetry of the recess, it is sufficient to refer to only one half in detail. The second half is mirror-symmetrical to the vertical S MThe first straight section 10 is formed by a tangent t1, which intersects a parallel P2 at an angle α of 45°. The parallel P2 runs parallel to the center line M and touches the base G of the recess 4. The second straight section 11 is defined by a tangent t2, which intersects the parallel P2 at an angle α / 2 (22.5°). The third straight section 12 is defined by the tangent t3, which intersects the parallel P2 at an angle α / 4 (11.25°) exactly at the base G of the recess 4. Furthermore, the distance a 2-3 the intersection points of the tangents t2 and t3 with the parallel P2 the distance a 1-2 the intersection points of the tangents t1 and t2 with the parallel P2 multiplied by the factor cos(α / 2) (0.924). Based on this design specification, the course, ie the outer contour of the recess 4, which takes on a concave shape, is predetermined.

[0033] The construction of the transition area 6 and the recess 4 was described above in an idealized manner to illustrate the basic construction of these outer contours. Of course, the straight areas 7, 8, and 9 can be connected to each other by curved areas, i.e., areas 7, 8, and 9 by means of convex intermediate areas, and areas 10, 11, and 12 by means of concave intermediate areas. It is also possible to use a completely curved outer contour, as long as the tangents T1, T2, and T3, as well as t1, t2, and t3, can be applied to this outer contour in the specified manner.

[0034] As an example, let us now look at the Fig.4, such a rounded design is indicated. It is difficult to see that straight and curved sections alternate here in the transition area 6. A similar process occurs with the outer contour of the recess 4. Furthermore, the transition area 6 is further rounded toward the front side 5, so that angular transitions are no longer present there either. The back 3 can also be rounded accordingly, so that there is only one single highest point on each side of the recess 4.

[0035] Overall, this design of the outer contour leads to a more uniform stress distribution and, compared to standard plates, to an increase in fatigue strength and a slight increase in breaking force. List of reference symbols 1 inner flap 2 Opening 3 back 4 recess 5 Front side a 1-2 Distance between intersection points a 2-3Distance between intersection points A 1-2 Distance between intersection points A 2-3 Distance between intersection points A M Distance to the center line A R Distance back B A Wide recess M center line P1 Parallel to the center line P2 Parallel to the center line S M Perpendicular to the center line S Vertical on the front side T A Deep recess t1, t2, t3 tangent T1, T2, T3 tangent α angle

Claims

[1] Link chain with alternating inner links (1) and outer links connected to each other by means of a chain joint, each having two openings (2) with a centre-to-centre distance of the pitch (T), characterized by that the transition region (6) between at least the back (3) and an end face (5) of an inner plate (1) and / or an outer plate has an outer contour such that three tangents (T1, T2, T3) can be applied to this contour, which satisfy the following conditions: that a) the first tangent (T1) with the point of contact closest to the front side (5) intersects a parallel (P1) touching the back (3) to the center line (M) passing through the centers of the two said openings (2) at an angle α, b) the second tangent (T2) with the second closest point of contact to the end face (5) intersects the said parallel (P1) at an angle α / 2, c) the third tangent (T3) with the third closest point of contact to the end face (5) intersects the said parallel (P1) at an angle α / 4, d) the distance (A 2-3 ) between the intersection points of the second and third tangents (T2, T3) with the said parallel (P1) the distance (A 1-2 ) between the intersection points of the first and second tangents (T1, T2) with the said parallel (P1) multiplied by the factor cos(α / 2), and e) the angle α in a) to d) is in the range from 40° to 50° and the factor in d) has a value in the range from cos 20° to cos 25°. [2] Link chain according to claim 1, characterized by that α has the value 45° and the factor in d) has a value of cos 22.5°. [3] Link chain according to claim 1 or 2, characterized bythat the first tangent (T1) forms a perpendicular (S) touching the front side (5) to the center line (M) passing through the centers of said opening (2) at a distance (A M ) to the center line M, which corresponds to 0.16 to 0.26 times the pitch (T). [4] Link chain according to one of claims 1 to 3, characterized by that the outer contour of the transition area (6) has both straight and curved areas. [5] Link chain according to claim 4, characterized by that the contact points of the tangents (T1, T2, T3) each lie in a straight area of ​​the outer contour of the transition area (6) and the straight areas are connected to one another by means of the curved areas. [6] Link chain according to one of claims 1 to 5, characterized by that the straight area closest to the end face (5) with the point of contact for the first tangent (T1) merges into the end face (5) by means of a convexly curved area. [7] Link chain, with alternating inner links (1) and outer links connected to one another by means of a chain joint, each having two openings (2) with a center-to-center distance of the pitch T, wherein at least the back (3) of the inner links (1) and / or the outer links has a substantially central, concave-shaped recess (4), characterized by that the recess (4) is on at least one side perpendicular to a line (S) intersecting the base (G) of the recess (4) M ) to the center line (M) passing through the centers of the openings has an outer contour such that three tangents (t1, t2, t3) can be applied to this outer contour, which satisfy the following conditions: that a) the first tangent (t1) with the perpendicular (S M) furthest point of contact, a parallel (P2) touching the base (G) of the recess (4) intersects the center line (M) passing through the centers of the two said openings (2) at an angle α, b) the second tangent (t2) with the said perpendicular (S M ) second furthest point of contact intersects the said parallel (P2) at an angle α / 2, c) the third tangent (t3) with the said perpendicular (S M ) third furthest point of contact intersects the said parallel (P2) at an angle α / 4, d) the distance (a 2-3 ) between the intersection points of the second and third tangents (t2, t3) with the said parallel (P2) the distance (a 1-2 ) between the intersection points of the first and second tangents (t1, t2) with the said parallel (P2) multiplied by the factor cos(α / 2), and e) the angle α in a) to d) is in the range from 40° to 50° and the factor in d) has a value in the range from cos 20° to cos 25°. [8] Link chain according to claim 7, characterized by that the greatest width (B A ) of the recess (4) at least 4 times the greatest depth (T A ) corresponds to the recess (4). [9] Link chain according to one of claims 7 or 8, characterized by that the outer contour of the recess (4) has both straight and curved areas. [10] Link chain according to one of claims 7 to 9, characterized by that the contact points of the tangents (t1, t2, t3) each lie in a straight area of ​​the outer contour of the recess (4) and the straight areas are connected to one another by means of the curved areas. [11] Link chain according to one of claims 7 to 10, characterized bythat the point of the back (3) with the greatest distance to the said center line (M) is at least at a distance (A R ) to the nearest end face (5), which corresponds to 0.45 times the pitch (T). [12] Link chain according to one of claims 1 to 11, characterized by that the inner plates (1) and / or outer plates have a symmetrical outer contour to the said center line (M). [13] Link chain according to one of claims 1 to 12, characterized by that the inner plates (1) and / or outer plates have a perpendicular to the perpendicular (S M ) have a symmetrical outer contour. [14] Link chain according to one of claims 1 to 13, characterized by that the inner plates (1) and / or outer plates are made of a rolled sheet material, wherein the rolling direction runs parallel to the center line (M) mentioned in a). [15] Inner link plate (1) or outer link plate for a link chain according to one of claims 1 to 14, characterized by that the inner plate (1) or the outer plate meets the specifications for the inner plate (1) or the outer plate from one of claims 1 to 6 as well as one of claims 7 to 14.

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