JP2017507292A - Blind rivet structure and joint - Google Patents

Abstract

A blind rivet structure (10) for generating a blind rivet joint (64), the blind rivet structure having a rivet body (12) and a mandrel (14), the rivet body (12) being a rivet head Part (20), a rivet shank (26) and a continuous rivet hole (30), the mandrel (14) includes a mandrel head (32) and a mandrel shank (36) inserted into the rivet hole. The rivet hole (30) includes a first hole cross section (D1) in the region of the end of the rivet shank (26) opposite the rivet head (20), and the mandrel shank (36) A first shank section (D2) is included in a first mandrel region (B1) adjacent to the mandrel head (32), the first shank section (D2) being a first hole section. (D1) It is adapted. In this case, in the second mandrel region (B2) protruding from the rivet hole (30), the mandrel shank (36) includes a second shank cross section (D3) that is smaller than the first shank cross section (D2). . [Selection] Figure 1

Description

  The present invention relates to a blind rivet structure for generating a blind rivet joint, the blind rivet structure having a rivet body and a mandrel, the rivet body comprising a rivet head, a rivet shank, and a continuous rivet. And the mandrel includes a mandrel head and a mandrel shank inserted into the rivet hole, the rivet hole being a first hole in the region of the end of the rivet shank opposite the rivet head. Including a cross-section, the mandrel shank includes a first shank cross-section in a first mandrel region adjacent to the mandrel head.

  The present invention further relates to a blind rivet joint having at least two workpieces and a blind rivet structure of the above type.

  Such a type of blind rivet structure is known from US Pat. No. 6,057,056 and is used to join workpieces accessible only from one side (viewing side). In this case, the blind rivet is inserted such that the blind mandrel head is passed through a hole provided in advance in the workpiece to be joined. Then, the fixing or joining operation is performed by pulling out the mandrel on the viewing side in a direction away from the arrangement of the workpiece (for example, by a blind rivet tool). This causes deformation of the rivet shank on the blind side, forming a blind head that abuts against the blind side workpiece surface after fixation. In principle, the mandrel shank includes a predetermined breaking point in this case, and once the fixing operation is performed, the mandrel shank protruding to the viewing side is broken and can be removed.

  The first shank cross-section is in this case preferably compatible with the cross-section of the first hole. This fit can be used to mechanically lock the rivet body and mandrel. Thereby, it is possible to prevent the rivet mandrel from being accidentally detached from the rivet body before the joining operation. In this case, it is known for the mechanical locking to be provided with an inflated part contoured in the first shank cross-sectional area, where the contoured inflating material of the rivet body is pressed against in the radial direction. (Impressing). The contoured inflated part is formed in particular by a radial protrusion.

  The hole cross-section of the rivet body is in this case uniform over the entire length of the rivet hole. The hole cross-section is designed in this case in such a way that the type and manner of fixing operation in each application is established in terms of the required rivet tensile and shear strength. As the hole cross section is increased, the shank cross section is also increased accordingly.

  Many problems can arise when small shank cross-sections are required as a result of processing techniques. On the other hand, mechanical locking by radial pressing can only be achieved by very deep pressing. As a result, only a relatively low holding force can be achieved. Deep pressing can in this case damage the rivet body in advance, and even the rivet body can be eroded by shear.

  Furthermore, there is a centering problem as a result of the large play between the inner periphery of the rivet hole and the outer periphery of the mandrel shank. In particular, a large misalignment may occur between the mandrel and the rivet hole. As a result, misalignment may occur. As a result, problems can also arise when working with rivets, especially when the mandrel shank must be inserted into a drawing mechanism that is slightly larger than the shank cross-section. In this connection, sometimes the rivet mandrel is no longer captured in the hole of the withdrawal mechanism.

  If the play between the inner diameter of the rivet hole and the outer diameter of the mandrel shank is too large, the large misalignment of the fixed rivet may not be negligible. This can cause rotationally symmetric deviations when the rivet shank is deformed, and thus can cause misalignment of the fixed blind rivet.

International Publication No. 2009/098431 German Patent Application Publication No. 10 2010 017 296

  Against this background, an object of the present invention is to provide an improved blind rivet structure and an improved blind rivet joint in which at least one of the above disadvantages is overcome.

  The mandrel according to the invention thus comprises a first mandrel region having a first shank cross section and a second mandrel region having a second shank cross section, the second shank cross section being a first shank cross section. Smaller than.

  The first shank cross section can be used with the first hole cross section of the rivet to center and / or guide the mandrel relative to the rivet body. Furthermore, mechanical fixation, for example by radial concave pressing, can be performed in this first mandrel region.

  The second shank cross-section can, by contrast, be clearly smaller so that blind rivet structures can be used even for application requirements where a small mandrel diameter is required.

  Accurate alignment of the mandrel shank with respect to the long axis can be achieved in one embodiment only as a result of the interaction between the first hole cross section and the first shank cross section. In other aspects of the invention, this is possible as a result of these means and / or further means.

  Therefore, as a result of the present invention, it is possible to eliminate the dependency that the conventional mandrel cross section is determined according to the hole cross section. As described above, the processing technology requirement for a specific mandrel section in the region of the interface with the processing apparatus can be satisfied as a result. Furthermore, the goal of material and hence cost reduction can be realized. Furthermore, it is possible to develop the blind rivet structure preferably in an optimum manner specific to the application. In particular, it may be possible to design rivet holes in an area that is reasonable to form a blind head in terms of requirements for rivet joints. In this way, quality requirements for rivet joining can be optimized where applicable.

  The objective is thus fully achieved.

  The transition between the first and second mandrel regions (ie, the transition between the first and second shank cross sections) is provided at any point inside the rivet mandrel (when viewed in the axial direction). be able to.

  However, it is particularly preferred that this transition is provided in the region of the predetermined break point.

  On the other hand, mandrels can be produced in a simple manner as a result. Furthermore, it is possible to adjust the breaking force at a predetermined breaking point in a relatively simple manner.

  According to a further preferred embodiment, within the region of the first mandrel region, the mandrel shank includes an outer peripheral contour that engages the inner periphery of the rivet hole.

  This type of contour can in particular be formed by radial protrusions originating from the outer periphery of the first shank area.

  This type of profile allows a mechanical lock between the mandrel and the rivet body by radial pressing in the first mandrel region, i.e. the pressing force is applied to the rivet body from the outside, which is applied to the rivet body. Push the material into the contour.

  The shank cross-section and the hole cross-section can have any cross-sectional shape, but are preferably provided in a circular manner so that the cross-section is defined by the respective diameter.

  In this case, the ratio between the diameter of the first shank section and the diameter of the first hole section is in the range between 0.80 and 0.99, in particular between 0.87 and 0.97. It is particularly preferable that it is within the range.

  In the case of this type of diameter ratio, on the one hand, radial pressing and thus mechanical locking is possible, and a high holding force can be realized. On the other hand, it is possible as a result to achieve a relatively good alignment or guidance of the mandrel into the rivet body.

  The ratio between the diameter of the first shank cross section and the diameter of the second shank cross section is preferably in the range between 1.01 and 3, in particular in the range between 1.05 and 2.5. In a particularly preferred manner, it is in the range between 1.1 and 1.85.

  Within this range, it is possible to realize blind rivet structures for a wide variety of different applications.

  Furthermore, it is generally advantageous if the first mandrel region extends over an axial length that is greater than 0.2 times the axial length of the rivet hole and / or less than 0.6 times the axial length of the rivet hole. It is.

  As a result of such axial length, the mandrel is well guided in the rivet body in the first mandrel region.

  According to a further preferred embodiment, the invention presents itself in conjunction with the premise of claim 1, in the region of the rivet head, the rivet hole is smaller than the first hole cross-section and the second Includes a second hole cross section that conforms to the shank cross section.

  As a result of this measure, an optimized alignment and guidance for the second mandrel region can be set.

  Furthermore, the structure of the transition between the first hole area and the second hole area inside the rivet hole allows the remaining rivet mandrel to be locked within the rivet body in a targeted manner. To. This can have a positive effect on the locking force of the remaining rivet mandrels.

  A further advantage may be that in the case of soft materials, as a result of the design of the transition geometry, the deformation of the rivet body can be stopped in a targeted manner and can therefore be adjusted. As a result, the result is achieved here that very soft workpieces (eg thin sheet metal, cardboard, leather, CFRP, etc.) are not deformed during the fixing process. Since the deformation limitation can be stopped early in this case, it is even possible to realize a playful joint where the blind rivet joint can act as a rotating shaft. Unlike conventional prior art, this blind rivet structure is therefore in a displacement-controlled manner, for example depending on whether the transition on the mandrel slides to the transition of the rivet hole. It can also be fixed.

  In order to achieve at least one of the above goals, the axial length of the region of the rivet hole having the second hole cross-section is greater than or equal to 0.4 mm, preferably the axial height of the rivet head. Preferred is greater than or equal to.

  Furthermore, it is preferable that an axial distance is set between the first mandrel region and the transition portion between the hole cross sections of the rivet holes. As a result, the mandrel is not guided in this intermediate area. In other words, the mandrel is preferably guided both in the first mandrel region adjacent to the free end of the rivet body and in the second region adjacent to the rivet head. As a result, ideal alignment of the mandrel with respect to the rivet body can be achieved even when the mandrel includes a smaller shank cross section in the second mandrel region than in the first mandrel region.

  According to a particularly preferred embodiment, in this case, the ratio between the diameter of the first hole section and the diameter of the second hole section is in the range between 1.01 and 3, in particular 1.05. Within the range between 2.5, in a particularly preferred manner between 1.1 and 1.85.

  Using this range of diameter ratios, rivet mandrels having a corresponding ratio between the first shank cross section and the second shank cross section can be guided and centered in an ideal manner.

  Furthermore, it is advantageous if the transition from the first hole cross section to the second hole cross section is arranged closer to the rivet head than the predetermined break point in the axial direction.

  In particular, in combination with the feature that the transition between the first mandrel region and the second mandrel region is formed in the region of the predetermined breakpoint, the result is that the unguided part is the first mandrel region Can be set inside the rivet hole between the second mandrel region and this can support deformation of the rivet body and form a blind head.

  In general, the blind rivet structure according to the present invention can be used in the design of any kind of blind rivet.

  However, it is particularly preferable that the blind rivet structure is a body-folded blind rivet structure. Such a type of body-folded blind rivet structure can be used for the purpose of joining in particular arrangements of workpieces with different axial thicknesses. As a result, compensation for different tightening thicknesses can be performed.

  Accordingly, the rivet shank includes a head forming portion provided for forming a blind head when generating the blind rivet joint, and is disposed between the head forming portion and the rivet head. It is particularly preferred to include a bent portion provided for the purpose of forming a body fold for compensating the clamping thickness when generating the blind rivet joint.

  These types of blind rivet structures are also referred to as variable grip rivets. Furthermore, this type of blind rivet structure is particularly suitable when at least one of the workpieces is a plastic material such as, for example, a thermoplastic material, a thermosetting plastic material, DFRP, or any other soft workpiece. It makes it possible to minimize such mechanical loads in the axial and / or radial direction on the surfaces and edges of objects.

  An example of this type of body-folded blind rivet is known from US Pat. No. 6,057,096, the disclosure of which is incorporated herein in its entirety by reference.

  In this case, an axial recess for receiving at least a part of the main body bent portion formed when the rivet head generates the blind rivet joint within the region of the contact surface that abuts the viewing-side workpiece surface. It is particularly preferable that

  A body-folded blind rivet of this type is known from the earlier patent application DE 10 2012 016 592.7, the disclosure of which is hereby incorporated in its entirety by reference.

  As a result of providing an axial recess in the rivet head, it is possible to provide a relatively large tightening area and join even for soft workpieces or workpieces that are weak against mechanical loads. . In particular, it is possible to keep the radial extent of the rivet body in the head region within tight limits, and to achieve the result here that the placement of the workpiece is not damaged during the fixing operation. it can.

  In general, the present invention can also claim rights in the form of a mandrel for a blind rivet structure of the type described above, where the mandrel includes a first mandrel region and a second mandrel region, where the mandrel is , Including a smaller shank cross section within the second mandrel region.

  In a corresponding manner, the present invention can also claim the right by the rivet body for a blind rivet structure including a hole, wherein in the region adjacent to the rivet head, the diameter of the hole is the rivet shank. Can be claimed in the form of a method that produces a blind rivet joint that is smaller than in the end region of the device, wherein the locking action is performed in a displacement control manner.

  Furthermore, the above object is achieved by a blind rivet joint having at least two workpieces and having a blind rivet structure of the above type.

  Overall, the present invention makes it possible to eliminate the dependency that the mandrel cross section is determined according to the hole cross section in the case of a blind rivet, particularly in the case of a body-folded blind rivet. In contrast to the prior art, blind rivet displacement control processing is possible.

  Furthermore, in the case of the present invention, at least one of the following advantages is achieved. The rivet mandrel diameter can be adapted to the processing equipment in an application independent manner. The amount of material used in the case of rivet mandrels and / or rivet bodies is reduced. The design of rivet holes can be done in a way specific to the application. As a result of mandrel guidance, the straightness of the fixed rivet is optimized. The function of the main body bending part in the axial recess of the rivet head is possible. The rivet body can be securely fixed to the mandrel. Designs with play or tightening suitable for the application are possible, including fixed displacement control. Damage in the case of soft bonding materials such as CFRP, cardboard, and leather can be prevented.

  It is clear that the features described above and those described below can be used not only in the combinations specified in each case, but also in other combinations or alone without departing from the framework of the present invention. .

  Exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

1 shows a schematic longitudinal sectional view of a first embodiment of a blind rivet structure according to the invention. Figure 7 shows a longitudinal section through a rivet body with a blind rivet structure according to a further embodiment of the invention. Fig. 3 shows a blind rivet structure using the rivet body of Fig. 2 during a fixing operation. 4 shows a blind rivet joint completed by the blind rivet structure of FIG. 3.

  FIG. 1 shows a schematic diagram of a longitudinal section of a first embodiment of a blind rivet structure according to the invention, generally indicated by the reference numeral 10.

  The blind rivet structure 10 includes a rivet body 12 and a rivet mandrel 14. The blind rivet structure 10 is used for joining the arrangement of workpieces including at least one first workpiece 16 (view side workpiece) and one second workpiece 18 (blind side workpiece). it can.

  The rivet body 12 includes a rivet head 20 in a known manner, which includes a contact surface 22 for abutting against the upper surface 24 of the viewing side workpiece 16. The rivet head 20 transitions to a rivet shank 26 that can be inserted into a workpiece hole 28 in the workpiece arrangement. The rivet body 12 has a rivet hole 30 continuous in the axial direction.

  The mandrel 14 includes a mandrel head 32 provided to abut the end surface 34 of the rivet shank 26. In addition, the mandrel 14 includes a mandrel shank 36 that is guided through the rivet hole 30 and extends out of the rivet head 20 on the viewing side.

  The rivet mandrel 14 also includes a predetermined break point 38.

To create a blind rivet joint, a rivet shank 26 is inserted into the workpiece hole 28 as shown in FIG. Then, the axial pulling force is, as shown by F ₁ in this case, exerted on the mandrel 14, the rivet head 20 is in the opposite direction of F _1, the F ₁ is greater than the second force F ₂ Retained.

Due to the mandrel head 32 abutting against the end face 34 of the rivet shank 26, the rivet shank is deformed on the blind side, so that a blind head is formed. In this case, the force F ₁ is in principle adjusted or increased so that once the blind head is completed, the mandrel 14 can break at a predetermined break point 38 and be pulled out of the completed blind rivet joint. .

The mandrel 14 includes a first mandrel region B ₁ and a second mandrel region B ₂ . The first mandrel region B ₁ extends from the mandrel head 32 through the rivet hole 30 to a predetermined breaking point 38. The second mandrel region B ₂ extends out of the rivet head 20 from a predetermined break point 38. Within the first mandrel region B ₁ , the mandrel shank 36 includes an outer diameter D ₂ that matches the first hole diameter D ₁ of the rivet hole 30. The diameters D ₁ and D ₂ are adapted to each other so that the mandrel 14 can be locked inside the rivet body 12 as a result of, for example, radial pressing. For this purpose, it may be advantageous to provide a radial protrusion 42 or other contour on the mandrel shank 36.

Within the second mandrel region B ₂ , the mandrel shank 36 includes a second shank diameter D ₃ that is smaller than the first shank diameter D ₂ .

In the region of the rivet head 20, rivet holes 30 includes a second bore diameter D _4. The second hole diameter D ₄ is smaller than the first hole diameter D ₁ . Furthermore, the second hole diameter D ₄ is adapted to the second shank diameter D ₃ . Axial region rivet holes 30 having a smaller second bore diameter D ₄ is preferably through the entire rivet head 20, which preferably in the direction of the rivet shank 26, indicated by reference numeral L ₄ in FIG. 1 It extends beyond the length that can be.

The axial height of the rivet head is indicated by the symbol L ₁ in FIG. The length of the rivet shank 26 in the axial direction is indicated by the symbol L ₂ in FIG. 1, and the distance between the contact surface 22 and the predetermined breaking point 38 is indicated by the symbol L ₃ in FIG. The outer diameter of the rivet shank 26 over the length is preferably uniform, indicated at D ₅ in FIG. 1.

The transition between the first hole portion having the first hole diameter D ₁ and the second hole portion having the second hole diameter D ₄ is a step or transition indicated by reference numeral 40 in FIG. It is formed by the part.

In general, what is achieved with the blind rivet structure 10 of FIG. 1 is that the rivet mandrel 14 can have a relatively small diameter in the region protruding from the rivet body 12. Nevertheless, the mandrel 14 can have a relatively large diameter in the first mandrel region B ₁ . Within the first mandrel region B ₁ , the mandrel is guided and centered axially relative to the rivet body 12. Furthermore, the diameters D ₃ and D ₄ are adapted to each other so that the mandrel is guided or centered by the rivet body 12 also in this axial region.

  The mandrel may not be guided between these areas inside the rivet body 12.

The spacing between the transition 40 and the predetermined break point 38 is such that the first mandrel region B ₁ impacts the transition 40 during the fixing operation, with the result that the break opening at the predetermined break point 38. In such a way that (breaking open) can be introduced, the displacement can be chosen to be controlled and fixed. As a result, the fixing operation can be realized so as to realize a predetermined tightening thickness.

  2-4 illustrate a further embodiment of a blind rivet structure 10 'that generally corresponds to the blind rivet structure 10 of FIG. Thus, identical elements are characterized by identical signs. The essential differences are explained below.

On the other hand, within the region of the rivet head 20, the rivet body 12 'shown in FIG. 2 includes an axial ring-shaped recess 44 that can serve to receive at least a portion of the body fold. The axial depth of the axial recess 44 is indicated by the symbol L ₅ in FIG. This axial depth L ₅ is smaller than the axial height L ₁ of the rivet head 20. The outer diameter of the rivet head 20 is indicated by the symbol D ₆ , and the outer diameter of the axial recess 44 is indicated by the symbol D ₇ .

The spacing between the bottom of the axial recess 44 and the transition 40 is denoted by L ₆ . This region also forms a folded portion 46 of the rivet shank 26.

Further, on the opposite end of the rivet head 20, the rivet shank 26 includes a head forming portion 50. A rigid portion 48 having a length indicated by L ₇ is provided between the head forming portion 50 and the bent portion 46. Axial length of the head forming portion 50, shown at L _8.

Head forming portion 50 includes a first formation portion 52 of axial length L _9, a second forming portion 54 of the second axial length L _10, a third axial length L ₁₁ of the Forming portion 56. The first forming portion 52 is adjacent to the blind end 58 of the rivet shank 26. The third forming portion 56 is adjacent to the rigid portion 48. The axial lengths L ₉ , L ₁₀ and L ₁₁ can be approximately the same size. The intermediate second forming portion 54 includes greater strength than the first forming portion 52 and the third forming portion 56. The folded portion 46 includes the minimum strength of the portions 46, 48 and 50.

  FIG. 3 shows the blind rivet structure 10 'during the securing operation. It can be seen that the blind head 60 formed by deforming the head forming portion 50 is formed during the fixing operation.

  FIG. 4 shows the completed blind rivet joint 64, in order to adapt the clamping thickness, the fold 46 forms a body fold 62, which is at least partly a rivet head of the rivet body 12 ′. It can be seen that it is disposed inside the axial recess 44 of the part 20.

Further, FIG. 4, the reference numeral L _12, showing the axial height of the axial depth L ₅ less than or At the main folding is preferably equal bend 62 in the axial direction the recess 44.

10: Blind rivet structure 12: Rivet body 14: Mandrel 16, 18: Work piece 20: Rivet head 22: Contact surface 24: Viewing side work surface 26: Rivet shank 28: Work hole 30: Rivet hole 32: Mandrel Head 34: End surface 36: Mandrel shank 38: Break point 40: Transition portion 42: Outer peripheral contour 44: Axial recess 46: Bending portion 48: Rigid portion 50: Head forming portion 60: Blind head 62: Body folding Bending portion 64: blind rivet joint B ₁ : first mandrel region B ₂ : second mandrel region D ₁ : first hole cross-sectional diameter D ₂ : first shank cross-sectional diameter D ₃ : second Shank cross section diameter D ₄ : second hole cross section diameter

Claims (12)

A rivet body (12) and a mandrel (14), the rivet body (12) including a rivet head (20), a rivet shank (26), and a continuous rivet hole (30); The mandrel (14) includes a mandrel head (32) and a mandrel shank (36) inserted into the rivet hole, the rivet hole (30) being opposite the rivet head (20). A first mandrel region (D ₁ ) located in the region of the end of the rivet shank (26), the mandrel shank (36) adjacent to the mandrel head (32) ( Blind rivet comprising a first shank cross section (D ₂ ) located within B ₁ ), the first shank cross section (D ₂ ) being adapted to the _first hole cross section (D ₁ ) Junction (6 ) The blind rivet structure for generating,
In the second mandrel region (B ₂ ) protruding from the rivet hole (30), the mandrel shank (36) has a second shank cross section (D ₃ ) that is smaller than the first shank cross section (D ₂ ). ). A blind rivet structure characterized by comprising 2. The blind rivet structure according to claim 1, wherein a predetermined breaking point (38) is provided at a transition between the first and second mandrel regions (B ₁ , B ₂ ). In the first mandrel region (B ₁ ), the mandrel shank (36) includes an outer contour (42) that engages the inner surface of the rivet hole (30). Item 3. The blind rivet structure according to Item 2. The ratio between the diameter of the first shank cross section (D ₂ ) and the diameter of the first hole (D ₁ ) is in the range between 0.8 and 0.99, in particular 0.87. The blind rivet structure according to any one of claims 1 to 3, wherein the blind rivet structure is in a range between 0.97. The ratio between the diameter of the first shank cross section (D ₂ ) and the diameter of the second shank cross section (D ₃ ) is in the range between 1.01 and 3, in particular 1.05 and 2 5. The blind rivet structure according to claim 1, wherein the blind rivet structure is in a range between. The first mandrel region (B ₁ ) is greater than 0.2 times the axial length of the rivet hole (30) and / or 0.6 times the axial length of the rivet hole (30). 6. Blind rivet structure according to any of claims 1 to 5, characterized in that it extends over a smaller axial length. In the region of the rivet head (20), a second rivet hole (30) is smaller than the first hole cross section (D ₁ ) and fits the second shank cross section (D ₃ ). It characterized in that it comprises a hole section (D _4), the blind rivet structure according to any one of claims 1 to 6. The ratio between the diameter of the first hole cross section (D ₁ ) and the diameter of the second hole cross section (D ₄ ) is in the range between 1.01 and 3, in particular 1.05 and 2 Blind rivet structure according to claim 7, characterized in that it is in the range between .5 and particularly preferably in the range between 1.1 and 1.85.   The transition (40) from the first hole cross section to the second hole cross section is closer to the rivet head (20) than the predetermined break point (38) of the mandrel (14) in the axial direction. The blind rivet structure according to any one of claims 7 to 8, wherein the blind rivet structure is arranged.   The rivet shank (26) includes a head forming portion (50) provided for forming a blind head (60) when generating the blind rivet joint (64), and the head A body fold (62) arranged between the forming part (50) and the rivet head (20) for compensating the tightening thickness when generating the blind rivet joint (64). 10. Blind rivet structure according to any one of claims 1 to 9, characterized in that it comprises a bent part (46) provided for the purpose of forming.   The body formed when the rivet head (20) generates the blind rivet joint (64) in the region of the contact surface (22) for abutting the viewing side workpiece surface (24). 11. Blind rivet structure according to claim 10, characterized in that it comprises an axial recess (44) for receiving at least part of the fold (62).   12. Blind rivet joint, characterized in that it has at least two workpieces (16, 18) and has a blind rivet structure (10) according to any one of claims 1 to 11 formed. (64).

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