Material connecting structure for thick plate

Abstract

The utility model discloses a material connecting structure for a thick plate, which is used for connecting an upper-layer plate and a lower-layer plate, the upper-layer plate has a first thickness, the lower-layer plate has a second thickness, and the ratio of the first thickness to the second thickness is greater than 2.5; the material connecting structure for the thick plate comprises a fastener, the fastener comprises a flange part and a rod part which are connected, and the diameter of the flange part in the axial direction is larger than that of the rod part in the axial direction; the end, away from the rod part, of the flange part is provided with a first face used for being attached to an upper electrode, and the end, away from the flange part, of the rod part is provided with a second face used for being attached to a lower layer plate. The fastener further comprises a groove, the groove extends in the axial direction, and an opening of the groove is formed in one side of the flange part, so that the attaching area of the first face and the upper electrode is annular. By means of the structure, the groove can be formed in the fastener to prevent the weld nugget from deviating, and the spot welding effect is improved.

Description

Technical Field

[0001] The utility model relates to a spot welding technology, in particular to a material connection structure for thick plates. Background Art

[0002] The description in this section merely provides background information related to the disclosure of the present utility model and does not constitute prior art.

[0003] Resistance spot welding is a common welding technology used to connect two metal workpieces together. It is generally used in assembly lines such as automobiles, fans and trains. Resistance spot welding applies high voltage between the contact surfaces of two metal workpieces and passes a large current, using the heat generated by the contact resistance to melt or reach a plastic state, thereby forming a weld. After the power is turned off, the weld becomes firm under the continued pressure, connecting the metal workpieces together. The above process usually includes stages such as pre-pressing, welding, maintenance and rest.

[0004] In existing mass production, usually a fastener is first stamped and fixed in one of the plates, and then one end of the other fastener is abutted against the surface of the other plate, and then one electrode is connected to the fastener and the other electrode is connected to the other plate, and then the electrodes are energized for spot welding. In the above process, since the fastener needs to be stamped into one of the plates, and the thickness of the stamped and fixed plate is too large, the weld core may deviate up and down along the thickness direction after spot welding, affecting the welding quality.

[0005] Currently, there is no material connection structure for thick plates that can solve the above problems. Utility Model Content

[0006] The utility model aims to provide a material connection structure for thick plates, which can avoid weld core deviation and improve spot welding effect by arranging grooves in fasteners.

[0007] In order to achieve the above object, an upper plate and a lower plate are connected, the upper plate has a first thickness, the lower plate has a second thickness, wherein the ratio of the first thickness to the second thickness is greater than 2.5; wherein the material connection structure for thick plates comprises:

[0008] A fastener, the fastener comprising a flange portion and a rod portion connected to each other, the diameter of the flange portion along the axial direction being larger than the diameter of the rod portion along the axial direction; wherein the end of the flange portion away from the rod portion has a first surface for bonding with the upper electrode, and the end of the rod portion away from the flange portion has a second surface for bonding with the lower plate;

[0009] Wherein, the fastener further includes a groove, the groove extends in the axial direction, and the opening of the groove is arranged on a side facing the flange portion, so that the first surface and the upper electrode contact area are annular.

[0010] Furthermore, a ratio of a thickness between the bottom surface of the groove and the second surface to the second thickness is less than 2.5.

[0011] Furthermore, the ratio of the thickness between the bottom surface of the groove and the second surface to the second thickness is greater than 1.

[0012] Furthermore, the groove has a preset width in the radial direction, so that the thickness of the annular wall formed by the rod portion at the outer periphery of the groove in the radial direction matches the thickness dimension of the flange portion in the axial direction.

[0013] Furthermore, the thickness of the annular wall formed by the rod portion on the outer periphery of the groove along the radial direction and the thickness of the flange portion along the axial direction are 1 mm.

[0014] Furthermore, the thickness between the bottom surface of the groove and the second surface is greater than the thickness of the annular wall formed by the rod portion at the outer periphery of the groove along the radial direction and the thickness of the flange portion along the axial direction.

[0015] Furthermore, the thickness between the bottom surface of the groove and the second surface is between 1.5-2 mm.

[0016] Furthermore, the outer wall of the rod portion includes circumferentially arranged flower teeth, so that when the fastener punches the upper plate, the material of the upper plate enters the flower teeth.

[0017] By means of the above technical solution, the beneficial effects of the utility model are as follows:

[0018] 1. The material connection structure for thick plates of the utility model can be provided with a groove on one side of the flange portion of the fastener. Based on the basic properties of the electric current, the physical plate thickness between the upper electrode and the lower electrode can be indirectly reduced to an acceptable level, thereby avoiding the problem of axial displacement of the weld core after spot welding due to excessive thickness of the upper plate, and improving the welding quality.

[0019] 2. The material connection structure for thick plates of the utility model is designed to have a thickness between the bottom surface of the groove and the second surface that is greater than the thickness of the annular wall formed by the rod portion along the radial direction at the outer periphery of the groove and the thickness of the flange portion along the axial direction. This ensures that the fastener of the utility model not only meets the spot welding yield rate requirements, but also ensures the basic fastener structural strength.

[0020] 3. The material connection structure for thick plates of the utility model can further reduce the weight of the fastener by setting the hollow groove, and can achieve lightweight structure. At the same time, the fastener of the utility model can be formed into a main body by cold heading, and the cost and material are lower by the existence of the groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 It is a schematic cross-sectional view of a spot welding structure for a material connection of a thick plate provided in an embodiment of this specification;

[0023] Figure 2 is a cross-sectional schematic diagram of a material connection structure for a thick plate provided in an embodiment of this specification;

[0024] Figure 3 It is a three-dimensional schematic diagram of a material connection structure for thick plates provided in an embodiment of this specification;

[0025] In the figure: 100, upper plate; 200, lower plate; 200a, third surface; 1, fastener; 11, flange; 111, recess; 12, rod; 126, tooth; 1a, first surface; 1b, second surface; 13, groove; 2, upper electrode; 3, lower electrode. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be described clearly and completely below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0027] In the description of the present utility model, it should be noted that the terms "upper", "middle", "lower", "inner", "outer", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model. The terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. The following describes the implementation method of the present utility model based on its overall structure.

[0028] See also Figure 1-2 , is a material connection structure for thick plates of this embodiment, used to connect an upper plate 100 and a lower plate 200, the upper plate 100 has a first thickness, the lower plate 200 has a second thickness, wherein the ratio of the first thickness to the second thickness is greater than 2.5; wherein the material connection structure for thick plates includes:

[0029] A fastener 1, comprising a flange portion 11 and a rod portion 12 connected to each other, wherein the diameter of the flange portion 11 along the axial direction is greater than the diameter of the rod portion 12 along the axial direction; wherein an end of the flange portion 11 away from the rod portion has a first surface 1a for bonding with the upper electrode 2, and an end of the rod portion 12 away from the flange portion 11 has a second surface 1b for bonding with the lower plate 200;

[0030] The fastener 1 further includes a groove 13 extending in the axial direction, and an opening of the groove 13 is arranged on a side facing the flange portion 11 so that the contact area between the first surface and the upper electrode 2 is annular.

[0031] Through the above structure, when in use, the operator first prepares the preset fastener 1, and then points the rod 12 of the fastener 1 toward the preset position of the upper plate 100, and performs a stamping operation of the fastener 1 on the upper plate 100, so that the rod 12 can punch a through hole in the upper plate 100, and stamp part of the material in the original upper plate 100 to the position between the flange 11 and the rod 12 in the fastener 1, so that the fastener 1 and the upper plate 100 form an interference fit or a stuck state, that is, the upper plate 100 and the fastener 1 are completely fixed, and at the same time, the rod 12 after stamping and fixing partially extends to the upper plate 100. The outer side of the layer plate 100, and then the second side 1b of the position where the rod 12 extends out can be placed in contact with the lower layer plate 200, and the upper electrode 2 and the lower electrode 3 can be energized, and during the energization process, the upper electrode 2 and the lower electrode 3 are squeezed toward the direction of the fastener 1 to perform spot welding, so that the fastener 1, the upper plate 100 and the partial area of ​​the lower plate 200 are subjected to the action of large current and extrusion, and deformed in a direction not parallel to the axial direction in a short time, and a new stable weld nugget is melted in the preset area, so that the partial area of ​​the fastener 1, the upper plate 100 and the lower plate 200 is fixed together, completing the final spot welding operation.

[0032] Among them, if the thickness of the upper plate 100 is too different from the thickness of the lower plate 200, such as in the present embodiment, the thickness of the upper plate 100 is more than 2.5 times that of the lower plate 200, the distance between the upper electrode 2 and the lower electrode 3 may be too far, causing the weld nugget to deviate up and down along the axial direction, significantly affecting the quality of spot welding. In a general spot welding operation environment, the ratio of the first thickness to the second thickness is less than 2.5 to avoid the upper plate 100 being too thicker than the lower plate 200 and the length along the axial direction being too long, resulting in the weld nugget being deviated along the axial direction when the weld nugget is formed, and failing to be formed in the preset area, affecting the effect of spot welding.

[0033] However, in this embodiment, by setting the groove 13, the space of the groove 13 can be used to accommodate the deformed material during the process of the upper electrode 2 applying pressure to the flange portion 11, and the thickness ratio between the upper plate 100 and the lower plate 200 can be indirectly reduced. For example, in this embodiment, the thickness of the upper plate 100 is 3mm, the thickness of the lower plate 200 is 0.7mm, and the thickness difference between the upper plate 100 and the lower plate 200 is more than 2.5 times, and the thickness between the bottom surface of the groove 13 and the second surface 1b is 1.5mm, that is, the ratio of the thickness between the bottom surface of the groove and the second surface to the second thickness is less than 2.5. In this embodiment, the actual physical thickness between the upper electrode 2 and the lower plate 200 is indirectly reduced, and the current can flow between the upper electrode 2 and the lower electrode 3 after passing through the fastener 1 area with a relatively small thickness. Spot welding in the case of this embodiment can effectively reduce the degree of displacement of the weld core along the axial direction.

[0034] In general, in the fastener 1 of the prior art without the groove 13 structure, the area where the weld nugget can be deflected is any position of the entire rod 12 along the axial direction. In the present embodiment, due to the presence of the groove 13, after the current passes through the annular wall surface formed by the rod 12 under the groove 13, the area where the weld nugget can be deflected is between the bottom surface of the groove 13 and the second surface 1b. Compared with the axial displacement range of the entire rod 12 with a larger size, no matter what the length of the rod 12 is, it will not affect the formation of the weld nugget in the present embodiment.

[0035] Further, the ratio of the thickness between the bottom surface of the groove 13 and the second surface 1b to the second thickness is less than 2.5, and the value is greater than 1. Specifically, since the displacement of the weld core along the axial direction is relatively controllable when the upper plate 100 and the lower plate 200 are generally within 2.5 times along the axial direction, the bottom wall thickness of the groove 13 of the fastener 1 in this embodiment can be set within the range of 2.5 times, simulating the situation that the upper plate 100 and the lower plate 200 are within 2.5 times along the axial direction; at the same time, in this embodiment, the bottom wall thickness of the groove 13 is also limited to be greater than the second thickness, in order to meet the fastener 1 as a welding point. Not only will there be no weld core displacement, but also after welding, it has a structural strength that meets the requirements of use.

[0036] Furthermore, the groove 13 has a preset width in the radial direction, so that the thickness of the annular wall formed by the rod portion 12 in the radial direction of the outer periphery of the groove 13 matches the thickness of the flange portion 11 in the axial direction. Specifically, in the present embodiment, the thickness of the annular wall formed by the rod portion 12 in the radial direction of the outer periphery of the groove 13 and the thickness of the flange portion 11 in the axial direction are both 1 mm. By limiting the thickness of the above-mentioned structure, it is firstly avoided that the main weld nugget may still be formed in the area of ​​the annular wall due to the excessive thickness of the annular wall formed by the rod portion 12 in the radial direction, resulting in welding failure, and the flange portion 11 of the fastener 1 can also maintain sufficient structural strength. During and after the spot welding process, the flange portion 11 can always be tightly pressed against the upper plate 100 while keeping itself from being deformed, resulting in the separation of the upper plate 100 and the lower plate 200.

[0037] Furthermore, the thickness between the bottom surface of the groove 13 and the second surface 1b is greater than the thickness of the annular wall formed by the rod portion 12 at the outer periphery of the groove 13 in the radial direction and the thickness of the flange portion 11 in the axial direction. Specifically, in this embodiment, the thickness between the bottom surface of the groove 13 and the second surface 1b is between 1.5-2mm, while the thickness of the annular wall formed by the rod portion 12 at the outer periphery of the groove 13 in the radial direction and the thickness of the flange portion 11 in the axial direction are both 1mm, and the difference in thickness is more than 1.5 times, so that after spot welding, there is a certain thickness between the bottom of the fastener 1 and the lower plate 200 that can meet the weld core strength but does not cause the weld core to deviate in the axial direction, which can reduce the yield rate of thick plate spot welding.

[0038] Specifically, in this embodiment, the upper plate 100 and the lower plate 200 can be made of the same material, such as both the upper plate 100 and the lower plate 200 are steel, or they can be made of different materials, such as the upper plate 100 is a lightweight metal such as aluminum and the lower plate 200 is steel, both of which can be connected using the method of the present invention.

[0039] like Figure 2-3 As shown, in another embodiment, the outer wall of the rod 12 includes teeth 126 arranged in the circumferential direction, so that when the fastener 1 is stamping the upper plate 100, the material of the upper plate 100 enters the teeth 126. Specifically, by setting the structure of the teeth 126, more material of the upper plate 100 can be embedded in the teeth 126 on the outer periphery of the rod 12 during stamping, so that the fastener used for spot welding can have a strong effect of resisting circumferential external forces. At the same time, this embodiment is particularly suitable for the case where the thickness of the upper plate 100 is relatively thick. With the cooperation of the teeth 126, more material can be embedded in the teeth 126, thereby significantly improving stability.

[0040] Although different specific embodiments are mentioned in the content of this application, this application is not limited to the situations described in the industry standards or embodiments, etc. Some industry standards or slightly modified implementation plans based on the implementation of the custom methods or embodiments can also achieve the same, equivalent or similar, or predictable implementation effects after deformation of the above embodiments. The embodiments of data acquisition, processing, output, judgment methods, etc. after these modifications or deformations can still fall within the scope of the optional implementation plans of this application.

[0041] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and changes to the present application without departing from the spirit of the present application. It is intended that the attached embodiments include these modifications and changes without departing from the present application.

Claims

1. A material connection structure for thick plates, used to connect an upper plate and a lower plate, wherein the upper plate has a first thickness and the lower plate has a second thickness, wherein: The ratio of the first thickness to the second thickness is greater than 2.5; characterized in that the material connection structure for thick plates comprises: A fastener, the fastener comprising a flange portion and a rod portion connected to each other, the diameter of the flange portion along the axial direction being larger than the diameter of the rod portion along the axial direction; wherein the end of the flange portion away from the rod portion has a first surface for bonding with the upper electrode, and the end of the rod portion away from the flange portion has a second surface for bonding with the lower plate; Wherein, the fastener further includes a groove, the groove extends in the axial direction, and the opening of the groove is arranged on a side facing the flange portion, so that the first surface and the upper electrode contact area are annular.

2. The material connection structure for thick plates according to claim 1, characterized in that: A ratio of a thickness between the bottom surface of the groove and the second surface to the second thickness is less than 2.

5.

3. The material connection structure for thick plates according to claim 1, characterized in that: A ratio of a thickness between the bottom surface of the groove and the second surface to the second thickness is greater than 1.

4. The material connection structure for thick plates according to claim 1, characterized in that: The groove has a preset width in the radial direction, so that the thickness of the annular wall formed by the rod portion at the outer periphery of the groove in the radial direction matches the thickness dimension of the flange portion in the axial direction.

5. The material connection structure for thick plates according to claim 4, characterized in that: The thickness of the annular wall formed by the rod portion on the outer periphery of the groove along the radial direction and the thickness of the flange portion along the axial direction are 1 mm.

6. The material connection structure for thick plates according to claim 4, characterized in that: The thickness between the bottom surface of the groove and the second surface is greater than the thickness of the annular wall formed by the rod portion along the radial direction at the outer periphery of the groove and the thickness of the flange portion along the axial direction.

7. The material connection structure for thick plates according to claim 6, characterized in that: The thickness between the bottom surface of the groove and the second surface is between 1.5-2 mm.

8. The material connection structure for thick plates according to claim 1, characterized in that: The outer wall of the rod portion includes teeth arranged in a circumferential direction, so that when the fastener punches the upper plate, the material of the upper plate enters the teeth.

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