JPS61275686A - Manufacturing apparatus line of sandwich metal plate - Google Patents

Abstract

PURPOSE:To inspect insulation inferiority of the upper and lower skin metal plates accurately and easily by providing a detector which inspects an insulation state on on-line of the whole quantity by an electric resistance detecting system to a manufacturing apparatus line of a sandwich metal plate. CONSTITUTION:A sheet of sandwich steel plate 18 passes between electrifying terminals 34 and 34' of a detector 32 provided to the outside of a shear of the sandwich metal plate manufacturing apparatus line via supporting rolls 28. The terminals 34 and 34' are impressed with the voltage by a power unit 36 and in case the insulation of the steel plate 18 is inferior, an electric current is flowed between the terminals 34 and 34' to measure the electric current with an ammeter 38.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an array of equipment for manufacturing sandwich metal plates (hereinafter simply referred to as "equipment array").

More specifically, the present invention relates to an apparatus for manufacturing sandwich metal plates that does not produce defects during electric resistance welding, in which an on-line inspection device is installed at an appropriate position on the manufacturing line.

(Prior Art) In recent years, reducing noise from many noise-generating machines such as transportation machines, processing machines, and electrical products has become a major issue. On the other hand, equipment and machinery are becoming lighter in weight in order to conserve resources, and lightweight materials are in demand. This trend is expected to further expand in the future.

As a solution to both of these problems, the use of a composite vibration damping steel plate called a so-called sandwich steel plate has been found to be highly effective, and in recent years, its characteristics of lightness and vibration damping have been further improved, and other specific improvements have been made. Active research and development is being carried out to improve the characteristics according to the intended use. Here, the composite damping steel plate has a sandwich structure in which a core resin material, which is a viscoelastic substance, is sandwiched between two upper and lower steel plates (hereinafter also simply referred to as "skin steel plate" or "skin metal plate"). It is something you have.

In addition, as another form of sandwich steel plate, an expensive metal plate such as a stainless steel plate or a titanium plate and an inexpensive metal plate such as a cold rolled steel plate or a plated steel plate are bonded together with an adhesive layer on both sides of the core resin material. There is something.

These sandwich steel plates laminated with dissimilar metal plates are not only useful industrially from the standpoint of resource conservation, but also can be used as composite materials that have excellent functions such as corrosion resistance and design by taking advantage of the characteristics of each skin metal plate. be.

Furthermore, by increasing the thickness of the core resin material, it is also possible to manufacture a sandwich steel plate that is lighter in weight or has further enhanced functions such as heat insulation.

As described above, in this specification, the sandwich metal plate includes not only a sandwich metal plate in which at least one side is a steel plate, but also a sandwich metal plate in which both are made of non-steel metal. For convenience of explanation, an example will be described in which steel plates are used as both skin metal plates.

(Problems to be Solved by the Invention) After manufacturing, these sandwich steel plates are formed into a desired shape using a press or the like and then assembled into a final product, and a joining technique is employed during the assembly. One such joining method is electric resistance welding such as spot welding and projection welding. However, since the resin constituting the core resin material is generally electrically insulating, it is essential to provide a short circuit (shunt circuit) between one metal plate and the workpiece during electrical resistance welding.

However, if a conductive substance is mixed into the core resin material that serves as the electrically insulating layer, causing poor insulation between the upper and lower skin metal plates, stray current will occur, resulting in defects such as burns and through holes.

The generation of this stray current will be explained with reference to FIG.

For example, when spot welding a sandwich steel plate 3 made of skin steel plates 1, 1' and a core resin material 2 and a common steel plate 5, a short circuit 6 is created between the skin steel plate 1 and the steel plate 5.
By providing this, the current flows along the path of upper electrode tip 7 - upper skin steel plate 1 - short circuit 6 - old steel plate 5 -> lower electrode tip 7° as shown by the double broken line in the figure. At this time, Joule heat is generated near 7.7° of both electrode tips,
Moreover, since both electrode tips are pressurized, the core resin material 2 softened or melted by Joule heat is expelled from between the electrode tips. Therefore, both skin steel plates 1.1' come into contact (not shown), and current flows as shown by the thick solid line in the figure, forming a nugget as in normal spot welding, and welding is completed. However, the situation is different when conductive foreign matter 4 is mixed into the core resin material 2. That is, in the figure, in addition to the short-circuit current as indicated by the double broken line described above, there is also a flow of the upper electrode chip 7 - upper skin steel plate 1 - conductive foreign matter 4 - lower skin steel plate 1 as indicated by the broken line in the figure.

- Ordinary steel plate 5 - Lower electrode tip 7'' A shunt occurs along the path. This is a so-called stray current. When this shunt occurs, Joule heat is generated in the conductive material 4, causing burning or, in severe cases, through-holes. This phenomenon is the same in both AC and DC resistance welding. Such conductive foreign matter includes unavoidable dust such as dust in a manufacturing factory, scratches on a steel plate, substances mixed in resin, and the like. Therefore, there is a high probability that the above-mentioned welding defects will occur in Santoi/7chi steel plates where the intermediate intervening layer of the core resin material is thin.

Considering that electric resistance welding is often used as a joining method for sandwich steel plates, it is desirable to establish an inspection method that completely checks such defects at the manufacturing stage, as such defects can be fatal.

However, methods using soft X-rays, ultrasonic waves, etc. can be considered as methods for inspecting conductive substances (insulation defects) that cause burns or through holes.
Those methods have the following drawbacks.

In other words, the size of the conductive foreign matter is generally several hundred micrometers or less, which is very small compared to the overall thickness of the sandwich steel plate, and it is necessary to spend time and detail to inspect it using the method described above. , it is unsuitable for full product inspection or online inspection. However, as mentioned above, the through holes may become a fatal defect depending on the use of the sandwich steel sheet, and therefore, a full product inspection or on-line inspection is essential. In addition, it is quite conceivable that insulating foreign matter that does not cause the formation of through-holes as described above may be unavoidably or intentionally mixed into the core resin layer during bonding, but soft X-ray method, ultrasonic However, it is very difficult to distinguish between these conductive foreign substances and insulating foreign substances.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sandwich steel plate manufacturing equipment line that can reliably and easily inspect insulation defects in upper and lower skin metal plates that cause through holes.

Means for Solving Problem C) Note that the present invention is a series of manufacturing equipment for sandwich metal plates constructed by interposing an insulating material between two metal plates, and which detects the insulation state of the entire quantity by an electric resistance detection method. This is a line of manufacturing equipment for Santoifuchi metal plates, equipped with a detection device for online inspection.

Here, the above-mentioned detection device can be placed at an appropriate position on the production line after the sandwich metal plates are formed, for example, installed on the output side of the gloss line, and inspected one by one after cutting to a predetermined length. Alternatively, it may be placed on the exit side of the slick or trimmer for continuous inspection prior to winding into a coil.

(Function) An example of the device array of the present invention is shown in a schematic explanatory diagram in FIG. This example is an apparatus for manufacturing sandwich steel plates.

The skin steel plate 1O11O° passes through the pretreatment line (degreasing, chemical conversion treatment, preheating, etc.) 12.12' and then goes to the lamination line 14.
supplied to On the other hand, the core resin material 16 is also supplied to the lamination line 14 to form a sandwich steel sheet with a three-layer structure.
In the case of the present invention, the specific configuration of this lamination line is not particularly limited. It can be appropriately selected from many already known ones. After that, the sandwich steel plate 18 passes through a cooling line 20, a drying line 22, a side trimmer 24,
The sheets are cut to a predetermined length by a shear 26, and then stacked on a bailer 30 via a support roll 28. In this case, it is desirable that the insulation state detection device 32 between the skin steel plates, which is the main structural unit of the present invention, be provided on the exit side of the shear 26, that is, at an appropriate position within the support roll 28.

The details of this insulation state detection device 32 will be described with reference to FIG. In this case, as shown in FIG.
6. Consists of an ammeter 38. The shape of the current-carrying terminal 34.34° may be any one of a roll, a brush, and a cloth. Another sandwich steel plate 18 moves on the support roll 28 and passes between the current-carrying terminals. At this time, if the upper and lower skin steel plates 10 and 10' of the sandwich steel plate 18 are insulated, no current will flow. However, if the insulation between the upper and lower skin steel plates is poor, current will flow between the current-carrying terminals. At this time, by checking the fluctuation of the voltmeter, defective products can be detected and scrapped. In this case, if the current-carrying terminal is in the form of a roll, a pressing force of 10 to 50 kg/aJ is appropriate, and the voltage of the power source 36 is 0.1 = 1 volt, and may be either alternating current or direct current. However, the appropriate amount of current is 10-10008. In the case of the cut plate manufacturing apparatus shown in FIG. 2, when the product is not between the current-carrying terminals 34.34°, it is desirable to open the gap or add a mechanism to stop the current flow.

Another aspect of the detection device preferably used in the present invention is that by preparing a power supply with a larger capacity, if there is an insulation defect, a large current will flow and Joule heat will be generated, resulting in a short circuit. There is also a method of inspecting defective products by creating burnt holes in the parts and detecting them by visual inspection or other appropriate means.

In the case of FIG. 2, the insulation state detection device 32 is provided on the exit side of the shear 26 because the upper and lower skin steel plates of the product must be insulated during inspection. That is, if the insulation state detection device 32 is located before the side trimmer 24, for some reason at the edge of the product, for example, the core resin layer is not filled up to the edge of the product and the upper and lower skin steel plates are short-circuited. This is because there is a possibility that the upper and lower skin steel plates are misaligned and a short circuit occurs due to the burr of the edge, and in such a case, detection becomes impossible. Furthermore, when the detection device 32 is placed before the shear 26, there are the following drawbacks. That is, since the sandwich steel plate manufacturing apparatus itself is made of metal for reasons such as rigidity, the upper and lower skin steel plates are each grounded. Therefore, if the insulation state detection device used in the present invention is placed before the shear 26, current will always be flowing, making it difficult to ensure the inspection accuracy. If placed later than this, sufficient insulation resistance of the upper and lower skin steel plates can be ensured, so inspection accuracy can be easily ensured.

Above, we have described the line of equipment for manufacturing sandwich steel plates, but the skin steel plates may be supplied to the lamination line 14 in the form of cut plates from the beginning, and in this case, the side trimmer 24
and shear 26 becomes a resher line. Further, when the supplied material is a cut plate, a press method may be considered in addition to the roll lamination method as shown in the figure. Furthermore, if the core resin material is solid at room temperature, the film lamination method is simple, but it is also possible to supply the resin directly onto the steel plate from an extruder, and if it is liquid at room temperature, a roll coater or curtain flow coater is used. It is also possible to apply and adhere it to a skin steel plate by, for example, the following methods.

Furthermore, the sandwich steel sheet manufacturing equipment line according to the present invention includes:
It is also possible to incorporate an accumulator, a leveler, a contact VAv device, etc.

Next, referring to FIG. 4, a description will be given of the case of a production equipment array for producing a sandwich steel plate in the form of a coil. The equipment row shown in FIG. 4 is essentially the same as the cut board manufacturing equipment row shown in FIG. . In this case, the insulation state detection device 32 is placed after the side trimmer 24. However, unless there is a sufficient distance between the grounding portions of the upper and lower skin steel plates and the detection device, it may be difficult to detect an insulation defect using a pair of current-carrying terminals.

In this case, for example, by using two pairs of current-carrying terminals and differentially inputting the voltage between the respective terminals, it is possible to perform accurate inspection. The principle will be briefly described below.

For example, if two pairs of current-carrying terminals AH, (:D) are provided between roll stands S1 and St installed at appropriate positions on a sandwich steel plate manufacturing line, when a voltage is applied between AH and CD, the voltage shown in FIG. A circuit like this is formed.In the figure, each symbol is as follows.

Ra, Ra, Re-RIl: Contact resistance R8 of each current-carrying terminal Rs*: Resistance RF of each roll stand S+, St
I% Rpzz Rpss RF4: Resistance R of skin steel plate from current-carrying terminal to roll stand 11% Rmc' Resistance R of skin steel plate between current-carrying terminals
F: Resistance of the upper and lower gaps in case of short circuit due to foreign matter At this time, once the material of the skin metal plate, the material and position of each component are determined, the electrical resistance between each element in Figure 5 is determined, and the electric resistance between each current-carrying terminal is determined. The voltage of is found by the following formula.

VAm= (Ra + R, +Rr++Rpz+
Rs+)・ramVsc"(Rs+RC
+ Rte) ・IncVce= (R(+RD +
RP3 + Rra + Rsz) ・ICDVoa
= (RA +Rn +Rao) ・Im++Here, Vow"VAt Vcs=0, Vot=Vsc-v
Consider the polarity of the applied voltage so that oa=0. Also, Va ” (VAllVc++) (Vmc
VDA) ■ so that it becomes Σ0. Adjust the input balance of the amplifier that uses the differential input Vat.

Now, when iron powder or the like that causes insulation defects gets mixed into the core resin layer (between the CDs in the figure), the current between the CDs! , flows, and VCII changes from the initial value to Vco=(Re + R
c + RF) ・I changes to r, so vo is R
It comes to show a value according to F. From this V, it is possible to know the insulation failure state.

An example of a circuit of a detection device having such a detection function is shown in FIG.

In FIG. 6, Ra and Rz are appropriately adjusted in advance in a steady state so that no apparent current flows between AB and CD. Then, when the insulation state between AB or CD becomes defective and current is applied during that time, the voltage change is detected and the insulation state is checked.

With this method, in order to find out where in the board width direction the cause of the insulation failure is, install several sets of measurement terminals in the width direction.
It is sufficient to provide as many measurement circuits as shown in FIG. 6 for the number of sets.

Above, we have described a series of manufacturing equipment for sandwich steel sheets whose essential unit is a device that detects the insulation state between two upper and lower steel sheets. For example, in the case of coil manufacturing equipment, once a product coil has been wound, It is also conceivable to arrange an array of devices such as performing slit processing and then detecting the insulation state.

The present invention will be further described below in connection with examples.

Example 1 Table 1 summarizes the results of applying the present invention to a sandwich steel sheet cutting plate production line equipped with the equipment array shown in FIG. Regarding materials that were found to have insulation defects on the production line,
It was taken out separately and subjected to a welding test, and the suitability of the inspection results on the production line was evaluated. The results of this welding test are also summarized in Table 1. For comparison, some results are also shown for those that were not energized. From the results shown in Table 1, the effects of the present invention are clear.

(The conditions were selected to be optimal for each steel plate.)

Example 2 Table 2 shows an example in which the present invention was applied to a sandwich steel plate coil production line equipped with the equipment array shown in FIG.

In this case, the material that was under the current-carrying terminal at the time of the voltage change was marked, and after winding it up on a recoiler, the marked material was cut into a length of 1 m, and the same welding test as in Example 1 was conducted. In this case, the test results were completely reliable.

Table 2 2 pairs of ar, differential input power (continued on next page) (Table 2 continued)

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a mechanism in which a stray current flows to a defective insulation location when spot welding sandwich steel plates; Fig. 2 is a schematic explanatory diagram of an example of a device array according to the present invention; , a schematic explanatory diagram of an example of a detection device for inspecting the insulation state between the upper and lower skin steel plates of a sandwich steel plate; FIG. 4 is a schematic illustration of another example of a device array according to the present invention A circuit diagram showing the principle of another type of detection device for inspecting the insulation state; and FIG. 6 is a wiring diagram showing a detection device based on the principle shown in FIG. 5. 10, 10° Niskin steel plate 12.12": Pretreatment line 14: Lamination line 16: Core resin material 1
8: Sandwich steel plate 20; Cooling line 22: Drying line 24: Side trimmer 26: Shear 28: Support roll 30; Baira

Claims (3)

[Claims] (1) An array of manufacturing equipment for sandwich metal plates constructed by interposing an insulating material between two metal plates, which is equipped with a detection device that inspects the insulation state of the entire quantity online using an electrical resistance detection method. manufacturing equipment row. (2) The manufacturing equipment array according to claim 1, wherein the detection device is disposed on the exit side of the shear line. (3) The manufacturing arrangement array according to claim 1, wherein the detection device is disposed on the outlet side of a slitter or trimmer.