JPH07217622A - Plasticity test method for rivet - Google Patents

Abstract

PURPOSE:To visually recognize metal plastic deformation generated after riveting by marking regulative line on the surface of a rivet before being used, carry out riveting on a material to be joined, taking out the rivet by breaking the material to be joined and observing deformation which appears on a marked line. CONSTITUTION:A line is marked on the axis part 1a and the head part 1b of a rivet 1 before riveting. The line is marked at a prescribed pitch space in the circumferential direction of the axis part 1a and the head part 1b, and at a prescribed angle in center axis direction including the head part 1b. The rivet 1 is inserted in the penetrating hole 2a of double laminated joined member 2, the axis part 1a is riveted by a riveter so as to be generated plastic deformation on the axis part 1a, and the joined material 2 is joined with the rivet 1. In this condition, the joined material 2 is broken, and it separates from the rivet 1, deformation of making line on the surface of the rivet 1 is observed, and plastic deformation which is generated after the rivet 1 is riveted is recognized by eyes, so that a material size can be restricted to the minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for testing and evaluation of a process of joining a plurality of members by a driving tool. The present invention relates to a method of observing how a rivet is plastically deformed by a rivet.

[0002]

2. Description of the Related Art A plurality of metal members are stacked by forming a common through hole, a metal stud having a head at one end is passed through the through hole, and the plurality of metal members are cold-tacked by a hydraulic stud. A method of joining members is widely used. Such a driving process is widely used in, for example, an automobile assembling process, a ship hull assembling process, a train or other vehicle assembling process, and the like.

In such a tacking process, the metal material of the metal tack is plastically deformed before and after the tack. After being struck, the stud will be permanently used in a plastically deformed state. Generally, the studs used in the assembling process of an automobile will retain a load of several tens of kilograms per square millimeter after the rivet is driven, for the entire life of the automobile.

In order to select the metallic material of the tack and design its size and shape, and to appropriately control the direction and magnitude of the force applied to this tack in the tacking process, the load that can be retained is determined. In order to be as efficient as possible and to reduce the weight of materials and products, correctly recognizing the metal plastic deformation of the tack before and after the tacking process is important for the designer of the device (for example, automobile) and the manufacturing process of the product. Very important to designers and managers.

In order to observe and evaluate the plastic deformation of the metal tack, the tack after the driving is taken out by breaking the material to be bonded,
Although it has been performed to make a metal cross-section and observe its metal plasticity with a metallographic microscope or the like, there is no known method for testing and observing the plastic deformation of the tack before and after the driving by a simple method.

[0006]

When the manufacturing / assembling process is to be improved or the design of a part of the product is to be improved, it is indispensable to carry out an appropriate design within a limited period.
Carefully cut the tack that has been subjected to plastic deformation of the sample, make a sample that can be observed with a metallurgical microscope, and other conventional observation methods will greatly increase the number of man-hours. There has been a demand for a method capable of easily observing metal plastic deformation.

The present invention has been made against such a background, and an object of the present invention is to provide a method capable of easily visually recognizing plastic deformation of a metal after a rivet is driven.

[0008]

One aspect of the present invention is a test method, and another aspect is a tack produced to perform the test.

That is, a first aspect of the present invention is to scribe a regular line on the surface of a tack before use, stab the tack to a material to be bonded, destroy the material to be bonded, and take out the tack. , It is characterized by observing the deformation that appears on the inscribed line.

Before use, the tack is cut into two in a plane including its central axis, a regular line is scribed on the cut surface, and the cut surface is adhered with an adhesive to drive the bonded material. , The bonded material is destroyed, the tack is taken out, the adhesive can be peeled off, and the deformation that appears in the injured line can be observed. Furthermore, for one hammer of one tack, the surface of the tack and its cut surface are observed. You can also observe the deformation that appears on the inscribed line after the rivet is struck.

A second aspect of the present invention is a rivet, in which a metal stud to be struck on a material to be joined is regularly marked on at least a part of its surface or its cut surface, It is characterized by being plastically deformed by a rivet.

The regular line can be in a grid pattern. The grid pattern is not necessarily a square grid, but may be a rectangular grid.

[0013] For scribing, it is convenient and good to scratch the metal surface with a tool having a high-hardness point, but in order to make a large number of specimens, a photo-etching method is used. Can be adopted. The depth of scribing is
It should be performed within a range such that the marking itself does not become unclear before and after the plastic deformation and the metal characteristics are not changed by the marking. About 0.5 to 0.3 mm is suitable.

[0014]

Function: A regular line is scribed on the surface of the rivet before the rivet at predetermined intervals in the axial direction and the circumferential direction, and the rivet scribed with the line is rivet-driven to the plastic to be deformed. The plastically deformed stud is taken out by breaking the material to be bonded, and the deformation appearing on the inscribed line is observed. Also, if you want to observe the deformation state inside the tack, cut the tack into two in the plane including the center axis, and at a predetermined interval in the direction perpendicular to the axial method and axial direction of the cut surface. It is possible to observe the change of the marking line on the cut surface by inserting regular marking lines, adhering with an adhesive, riving into the material to be bonded and plastically deforming, taking out the plastically deformed tacks and dividing .

With this, it is possible to easily visually recognize the state of plastic deformation after the rivet is struck for joining a plurality of members with a small number of steps and without taking a lot of time.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

(First Embodiment) In the first embodiment of the present invention, a regular line is scribed on the surface of the tack before being struck, the tack is struck on the material to be bonded, and then the material to be bonded is destroyed. Then, take out the tack and observe the deformation that appears on the injured line.

The test method will be described step by step. Figure 1
Shows the external shape of the tack before being struck in the first embodiment of the present invention. In the first embodiment, d ₁ = 13 mm, L ₁
= 36 mm and L ₂ = 45 mm. First, as shown in FIG. 2, the stud 1 has its shaft portion 1a.
And a marking line is put on the head 1b. In the case of the present embodiment, the scribing lines are arranged at intervals of a pitch P _S = 1 mm on the circumferences of the shaft portion 1a and the head 1b, and an angle P _R = 10 ° in the central axis direction including the head 1b. A marking line is inserted at intervals of. The pitch P _S and the angle P _R are 1 mm and 1
The value is not limited to 0 °, and a suitable value can be selected depending on the size of the tack, the degree of plastic deformation to be confirmed, or other required conditions.

Such scoring work is generally carried out by attaching tacks to an indexing disk and indexing the angle with a tool such as a Tohsukan equipped with a high-hardness point, but in the case of producing a large number of samples. Can be performed by a photo-etching method.

The depth of the scribed line is from 0.05 to 0.05 so that the scribed line does not become unclear before and after the plastic deformation and the scribed line does not affect the strength characteristics of the sample.
About 0.3 mm is suitable.

Next, t × w ₁ × w ₂ = 7 shown in FIG. 3 as a raw material for the bonded material 2 for driving the scribed rivet 1.
Two flat plate materials of mm × 100 mm × 100 mm are prepared. The size of the material to be bonded 2 can be selected according to the purpose of the test. A through hole 2a of d ₂ = 14 mm is machined at the center of the two flat plate materials as shown in FIG. 4, and D = from the center of the through hole 2a as shown in FIG.
Width w = 0.2 mm on both sides over a length of 12 mm
Groove 2b is formed. The groove 2b is for cutting the material to be bonded 2 by wire cutting after the tack 1 is driven.

Then, the through hole 2a of the material 2 to be bonded in a two-layer structure
As shown in FIG. 6, the tack 1 is inserted, and when the shank 1a is driven by the tacking machine, the shank 1a is plastically deformed, so that the two bonded members 1 are separated as shown in FIG. Firmly combined. Here, the groove 2b is used to perform wire cutting of the bonded material 2 as shown in FIG. 8, and the tack 1 and the bonded material 2 are separated as shown in FIG. Deformation of the scribe line appears on the surface of the tacked rivet 1, and by observing the state of this deformation, it is possible to visually recognize what kind of plastic deformation will occur after the rivet 1 is struck.

(Second Embodiment) In the second embodiment, a stud before use is cut into two in a plane including its central axis, a regular line is scribed on the cut surface, and the cut surface is bonded. Adhesive with adhesive and rivet to the bonded material, break the bonded material and take out the tack
The adhesive is peeled off and the deformation that appears on the injured line is observed.

The test method will be described step by step. Tack 1
Figure 1 until you insert the marking line and prepare the material to be bonded 2.
The procedure is similar to that of the first embodiment shown in FIG. In the second embodiment, the rivet 1 having the marking lines shown in FIG. 2 is divided by a wire cut into two planes including the central axis as shown in FIG. Scribing lines are formed on each of the two cut surfaces as shown in FIG. In the case of the second embodiment, it is assumed that a grid-shaped marking line having a pitch P _S = 1 mm is inserted. The cut surface in which the scribe line is thus formed is bonded with an adhesive as shown in FIG. 12, and is inserted into the through hole 2a as shown in FIG.

When the shaft portion 1a of the tack 1 is driven by the driving tool in such a state, the shaft portion 1a undergoes plastic deformation as in the first embodiment, and two shafts 1a and 2a are formed as shown in FIG. The bonding material 1 is firmly bonded. Here, the groove 2b is used to perform wire cutting of the bonded material 2 as shown in FIG. 15, so that the tack 1 and the bonded material 2 are separated as shown in FIG. Is divided.

Deformation of a scribe line appears on the surface and cut surface of the rivet 1 that has been struck, and by observing the state of this deformation, it is possible to recognize what kind of plastic deformation will occur after the rivet 1 is struck. be able to.

[0027]

As described above, according to the present invention, it is possible to easily visually recognize the state of plastic deformation depending on how the line that has been inscribed before the tacking changes after the tacking. . Therefore, it is possible to reduce the number of man-hours in the experimental stage before the strength design and to accurately grasp the form of plastic deformation, so that the size and shape can be set most effectively.

Further, since the raw material to be used as the tack is selected by observing the actual state of the plastic deformation, it becomes possible to properly control the direction and the magnitude of the force applied to the tack in the tacking process. Can improve the reliability of
Furthermore, since the material size can be minimized,
It is extremely effective in reducing the weight.

[Brief description of drawings]

FIG. 1 is a perspective view showing the external shape of a tack before being driven in the first embodiment of the present invention.

2 (a) and 2 (b) are a side view and a plan view showing a state where the surface of the tack in the first embodiment of the present invention is scratched.

FIG. 3 is a perspective view showing an external shape of a material to be joined in the first embodiment of the present invention.

FIG. 4 is a perspective view showing a state in which a tack hole is formed in a material to be bonded in the first embodiment of the present invention.

FIG. 5 is a perspective view showing a state in which a tack hole and a wire cutting groove are formed in the material to be bonded in the first embodiment of the present invention.

FIG. 6 is a perspective view showing a state in which a tack is inserted through a material to be coupled in the first embodiment of the present invention.

FIG. 7 is a perspective view showing a state in which the tack in the first embodiment of the present invention is driven into the material to be joined.

FIG. 8 is a perspective view showing a state in which the material to be coupled is cut by wire cutting after the driving in the first embodiment of the present invention.

FIG. 9 is a perspective view showing a state in which the tack and the material to be coupled are separated from each other in the first embodiment of the present invention.

FIG. 10 is a perspective view showing a cut state of the tack in the second embodiment of the present invention.

FIG. 11 is a perspective view showing a state where a cut surface is scribed in the second embodiment of the present invention.

FIG. 12 is a perspective view showing a state of being adhered after scribing on a cut surface in a second embodiment of the present invention.

FIG. 13 is a perspective view showing a state in which a tack is inserted through a material to be coupled in a second embodiment of the present invention.

FIG. 14 is a perspective view showing a state where the tack in the second embodiment of the present invention is driven into the material to be joined.

FIG. 15 is a perspective view showing a state in which the material to be coupled is cut by wire cutting after the driving in the second embodiment of the present invention.

FIG. 16 is a perspective view showing a state in which the tack and the material to be coupled are separated from each other in the second embodiment of the present invention.

[Explanation of symbols]

 1 Tack 1a Shaft 1b Head 2 Bonded material 2a Through hole 2b Groove

Claims (5)

[Claims] 1. Deformation that appears on the inscribed line by scribing regular lines on the surface of the tack before use, driving the tack into the material to be joined, destroying the material to be joined and taking out the tack A method for testing plasticity of tacks, which is characterized by observing. 2. A stud before use is cut into two in a plane including its central axis, a regular line is scribed on the cut surface, and the cut surface is adhered with an adhesive to strike a material to be bonded. A method for testing the plasticity of a tack, characterized in that the tack is broken, the material to be bonded is broken, the tack is taken out, the adhesive is peeled off, and the deformation appearing on the injured line is observed. 3. A stud plasticity testing method in which the method according to claim 1 and the method according to claim 2 are combined for one hammer and one hammer. 4. A metal stud having regular line markings on at least a part of the surface or a cut surface for observation. 5. The metal stud according to claim 4, which is plastically deformed by a stud.