JP2001004514A - Strength evaluating method of bent part and evaluation data measuring jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a strength evaluating method of a bent part capable of easily performing the selection of a material fitted to a use condition or the selection of a working condition without largely consuming time or cost and an evaluation data measuring jig used therein. SOLUTION: In a method for evaluating the strength of the bent part of a connection terminal formed by bending a plate-shaped member, load is applied to an elongated plate-shaped test piece 17 having the corresponding bent part 17a subjected to bending at the intermediate part thereof in the same way as the connection terminal on both sides in the vicinity of the corresponding bent part 17a to gradually deform the test piece in a direction wherein the inside angle of the corresponding bent part 17a becomes smaller. Then, the quantity of deformation displacement in the load direction in the vicinity of the corresponding bent part 17a until extending to the occurrence of damage such as cracking or breaking in the corresponding bent part 17a is measured and the strength of the corresponding bent part of the connection terminal is evaluated on the basis of the magnitue of the quantity of deformation displacement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal connecting part (so-called connecting terminal) for connecting electric wires of automobiles and industrial equipment and electric / electronic equipment mounted thereon to supply electric signals and power from a power source. ), Etc., to evaluate the strength of a bent part of a bent metal plate-like member by bending deformation amount until the occurrence of damage to the bent part. And a jig for measuring evaluation data used therein.

[0002]

2. Description of the Related Art As an example of a bent product obtained by bending a metal plate-like member, there is a connection terminal formed by bending a thin metal plate, which is used for connecting electric wires. For example, in connection between electric wires, as shown in FIG. 8, a male terminal 2 as a connection terminal is crimped to one end of one electric wire 1 and a corresponding connection end is formed at the other end of the other electric wire 3 as well. The female terminal 4 is crimped, and the elongated plate-shaped tab portion 2a provided at the distal end of the male terminal 2 is inserted into the rectangular tubular connection cylindrical portion 4a provided at the distal end of the opposite female terminal 4. By the insertion, the elastic piece 4b provided in the connecting cylinder 4a so as to be elastically deformable is elastically deformed, and the elastic return force of the elastically deformed elastic piece 4b causes the inner surface of the connecting cylinder 4a and the elastic piece to be elastically deformed. The tab portion 2a is sandwiched between the two terminals 2 and
The four wires are electrically connected to each other, and the electrical connection between the wires 1 and 3 is secured here.

[0003] In connection using a normal connector, for example, male terminals having the above-described structure crimped to the ends of the electric wires are respectively housed and held at predetermined positions of one connector housing. At each predetermined position of the other corresponding connector housing, the female terminal having the above-described structure crimped to the end of each electric wire is housed and held, respectively, and the two connector housings are fitted and connected to each other, whereby each The male terminal and each female terminal are configured so as to collectively obtain the connection state as described above.

[0004] The connection between the electric wire and the device is also configured in the same manner as the connection structure using the connector as described above.

[0005]

On the other hand, recent automobiles are equipped with electronic devices such as car navigation systems and audio devices, and systems such as ABS, airbags, 4WS, and four-wheel steering devices. The number of electrical wirings has been increasing, and the number of electrical wirings has increased accordingly, and there has been a strong demand for miniaturization and multipolarization of connectors.

However, when reducing the size of the connection terminal used for this kind of electric wiring, the bending radius of the bending portion to be bent is usually small. At this time, if a soft material (for example, a ductile material) excellent in bending workability is used as the terminal material, the spring action of the elastic piece portion 4b cannot be sufficiently exerted, and the tab portion 2a and the inner surface of the connection cylinder portion 4a and the elasticity of the elastic member 4b cannot be obtained. There is a problem that a sufficient contact pressure cannot be obtained between the mutual contacts with the piece 4b.

[0007] Conversely, a material (for example, an elastic material) capable of obtaining a sufficient contact pressure has a problem that the connection terminal cannot be bent due to generation of cracks (cracks) and the like.
For example, as shown in FIGS. 9 and 10, a spring portion 4 c as a bent portion that is bent and contributes to the elastic deformation of the elastic piece portion 4 b, and a bent portion formed to form the connection tube portion 4 a. Cracks are likely to occur at each bent corner 4d as a processed portion, and there is a problem in durability.

For this reason, a material that achieves both elasticity and workability has been developed as a material for the connection terminal. As a method for processing the connection terminal, for example, a 90-degree bend is formed by two bending operations. 90 times by bending four times
Reduction of the degree of processing by one bending processing, such as reducing the damage to the material by forming a degree bending, etc.
Improvements such as a reduction in bending speed have been made.

However, it is difficult to relatively compare the effect of the improvement and the difference in damage due to the difference in the processing method. In practice, various types of male and female terminals are used depending on various materials and various processing conditions. Manufacture each and leave them alone or mounted in the connector housing in various environments such as high temperature environment or vibration application environment, and fluctuate the electric resistance and pinch the tab part of the male terminal By measuring the change in the contact pressure and evaluating the durability of the connection terminal, the suitability of processing conditions and the suitability of material selection were indirectly confirmed.

For this reason, it has required a great deal of time and cost to select a material suitable for the connection terminal corresponding to the use condition and to determine the processing condition suitable for the bending process.

An object of the present invention is to provide a method for evaluating the strength of a bent portion and a method for evaluating the strength of a bent portion which can easily select a material and a processing condition suitable for use conditions without spending much time and money. It is an object to provide a jig for data measurement.

[0012]

The technical means of the method for solving the above-mentioned problems is to evaluate the strength of a bent portion of a bent product formed by bending a plate-like member. An evaluation method, in which an elongated plate-shaped sample piece having a corresponding bent portion bent at the middle portion in the same manner as the bent product is subjected to a load by applying a load from both sides near the corresponding bent portion. Deformation is gradually performed in a direction in which the inside angle of the processed portion becomes smaller, and the deformation displacement amount in the load direction in the vicinity of the corresponding bent portion until the occurrence of damage such as crack or breakage of the corresponding bent portion is measured. However, the strength of the bent portion is evaluated based on the magnitude of the deformation displacement.

[0013] The bent product may be a connection terminal.

Further, the technical means of the jig used in the above-mentioned strength evaluation method includes a posture holding portion for holding the sample piece in a predetermined posture, and a jig for the corresponding bending portion of the sample piece held in the posture. A load acting body which is disposed to face the load from both sides in the vicinity, a load acting body moving unit which moves the two load acting bodies toward and away from each other in the load direction, and a load acting body which detects the amount of deformation displacement. And a displacement amount detection unit for detecting a movement amount.

Further, one of the opposing load acting bodies is mounted and fixed on the substrate, and the other load acting body is supported on the substrate so as to be reciprocally movable in the load direction. The opposing surfaces of the body opposing each other are inclined opposing surfaces that gradually expand in a downward direction corresponding to the inclination along the extending direction of each of the extension pieces on both sides of the corresponding bending portion of the sample piece, The posture holding unit includes a fixing plate detachably attached to and fixed to the inclined opposing surface so as to fix and hold one of the extending pieces on the inclined opposing surface of the load acting body fixed and attached. The displacement amount detection unit may be configured to be mounted and supported on the substrate side so as to detect a movement amount of the load acting body supported to be reciprocally movable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a male terminal 2 as an example of a bent product obtained by bending a metal plate member. 1 shows an evaluation data measuring jig 10 used in a method of evaluating the strength of a bent portion of a connection terminal such as a female terminal 4 or the like, and is provided on a rectangular plate-shaped substrate 11 and detachably mounted on one end of the substrate 11. A fixed-side load acting body 12 attached and fixed; a movable-side load acting body 13 supported on the other side of the substrate 11 so as to reciprocate in the direction of the fixed-side load acting body 12; An operation screw shaft 14 serving as a load acting body moving unit for moving the movable body in the direction of the fixed load acting body 12, and a micrometer 15 serving as a displacement amount detecting unit which detects a moving amount of the movable load acting body 13. It is configured.

In FIG. 2 and FIG. 3, reference numeral 17 denotes an elongated plate-shaped metal spring material (for example, a copper alloy for a terminal) having an appropriate length and width, and an intermediate portion thereof which is the same as the spring portion 4c and the bent corner portion 4d. In the sample piece 17 having the corresponding bending portion 17a bent into a shape, for example, as shown in FIG. 3, the plate thickness t is 0.25 mm, and the bending angle θ of the corresponding bending portion 17a.
Are formed at 90 degrees, the bending radius R is 0.25 mm,
Various types such as 5 mm and 0.75 mm are prepared.

The opposing surfaces of the fixed-side load acting body 12 and the movable-side load acting body 13 oppose each other in the extending direction of the extending piece portions 17b on both sides of the corresponding bent portion 17a of the sample piece 17. The inclined opposing surfaces 12a and 13a (in the present embodiment, the inclined opposing surfaces having a downward angle of 45 degrees) which gradually expand in the downward direction corresponding to the inclination along.

A fixed plate 19 in the form of a rectangular flat plate is provided on the inclined opposing surface 12a of the fixed-side load acting body 12 so as to fix and hold one extended piece portion 17b of the sample piece 17 in a sandwiched manner. For example, the hexagon socket head bolt 20 is inserted into the bolt insertion hole 1
The fixing plate 19 is configured to be removably attached and fixed to the inclined opposing surface 12a by being screwed into a female screw hole formed in the inclined opposing surface 12a while being inserted through the fixing plate 9a.

The movable-side load acting body 13 is narrower than the fixed-side load acting body 12 and wider than the sample piece 17, and has a rectangular flat slide plate 13b below it.
Is installed. A slide plate 13b is fitted on the upper surface side of the substrate 11, and the slide plate 13b
A rectangular concave guide groove 11a for slidingly guiding the movable plate 12 toward and away from the fixed side load acting body 12 is formed. Further, the slide plate 13b is prevented from coming off from the guide groove 11a, and the movable side load operation is performed. An elongated plate-like guide plate 21 for guiding the body 13 in the direction of the fixed load acting body 12 straddles the guide groove 11a on both sides of the movable load acting body 13,
Each is detachably bolted to the substrate 11.

Further, a support block 22 is detachably bolted on one end edge of the substrate 11 opposite to the fixed side load acting body 12, and the operation screw shaft 14 is attached to the movable side load acting body 13. It has an axis in the sliding direction and is supported by the support block 22 in a threaded state. An operation rod 14a is supported at one end of the operation screw shaft 14 so as to be movable in a direction orthogonal to the axis.
The other threaded end of 4 is in contact with the movable face of the movable load applying body 13 so as to be able to freely contact with and separate from the pressing face 13c opposite to the inclined face 13a.

The screw insertion end pushes the pressing surface 13c by the screwing operation of the operation screw shaft 14, and the movable load acting body 13
Is moved in a direction approaching the fixed-side load acting body 12, and the screw insertion end and the pushing surface 13 c are separated from each other by the retreating operation of the operation screw shaft 14, and the movable-side load acting body 13 Can be moved in a direction away from the fixed-side load acting body 12.

Further, on one side surface of the movable-side load acting body 13, an overhang block 13d for measuring the amount of movement is mounted in a laterally overhang shape. The micrometer 15 is mounted and supported in parallel with the operation screw shaft 14 at a position of the support block 22 facing the overhang block 13d, that is, at a position located on one side of the operation screw shaft 14 of the support block 22. The detection shaft 15b, which is moved back and forth along the axis parallel to the axis of the operation screw shaft 14 by the forward / reverse rotation operation of the rotation operation unit 15a of the micrometer 15, causes the extension block 13d.
Is configured so as to be able to freely contact and separate from the detection surface 13e.

Next, a method of using the evaluation data measuring jig 10 will be described. One of the extension pieces 17b of the sample piece 17 is connected to the inclined opposing surface 12a of the fixed-side load acting body 12 and the fixed plate 19. It is attached and fixed at a predetermined position as a holding shape, and is held in a predetermined posture as shown in FIG.

Thereafter, the operating screw shaft 14 is screwed forward to move the movable load acting body 13 in the direction of the fixed load acting body 12, and as shown in FIG. The surface 13a is connected to the other extension piece portion 17b of the sample piece 17.
Contact. At this time, the upper ends of the inclined opposing surfaces 12a and 13a are in contact with both sides of the sample piece 17 in the vicinity of the corresponding bent portion 17a.

In this state, the tip of the detection shaft 15b is brought into contact with the detection surface 13e by rotating the rotation operation part 15a of the micrometer 15, and the reference contact position is set to the scale part 15c of the micrometer 15. Read with.

Next, the operation load shaft 13 is gradually moved in the direction of the fixed load application body 12 by gradually operating the operation screw shaft 14. At this time, the fixed-side load acting body 12 and the movable-side load acting body 13 are moved closer to each other, and as shown in FIG. 3, a direction in which the inner angle (so-called θ) becomes smaller than both sides near the corresponding bending portion 17a. , And is gradually deformed in a direction in which the bending angle θ is further deepened as indicated by a virtual line.

Then, when the corresponding bending portion 17a is damaged, for example, when a crack due to a crack is generated, or when the crack grows and breaks, the screwing operation of the operation screw shaft 14 is stopped. In this state, the rotation operation section 15a of the micrometer 15 is rotated to operate the detection shaft 15
The tip of b is brought into contact with the detection surface 13e, and the contact position at the time of this damage is read by the scale 15c of the micrometer 15.
The corresponding bending portion 17a in the direction in which the load is applied due to the difference between the read data of the scale portion 15c at the damage contact position and the read data at the reference contact position.
The deformation displacement d in the vicinity can be measured indirectly.

If this deformation displacement d is measured with various materials having various tensile strengths, the corresponding bending portion 17
The corresponding bending section 17a depends on the magnitude of the deformation displacement d, such that the larger the deformation displacement d of a, the greater the strength up to damage, and the smaller the deformation displacement d, the lower the strength until damage. , That is, durability against displacement, can be quantitatively evaluated.

The deformation displacement d measured in this way,
The relationship between the tensile strength, the thickness t, and the bending radius R is shown in FIG.
It becomes as shown in. In FIG. 4, the solid line is data of the same kind of material such as brass having excellent bending workability.
The dotted line is data of the same material having poor bending workability.

Therefore, according to the present embodiment, it is possible to evaluate the strength of the corresponding bent portion 17a by applying a load to the vicinity of the corresponding bent portion 17a.
It is possible to quantitatively evaluate the strength in a state where a change in physical properties such as work hardening accompanying bending is incorporated.

Then, as shown in FIG. 4, the bending workability can be relatively determined from the relationship between the deformation displacement d leading to the occurrence of damage such as cracks and breakage and the tensile strength of the material. If the metal plate has the same plate thickness t, it is possible to determine how much the deformation displacement d changes by changing the bending radius R, and the larger the deformation displacement d, the better the bending workability. Therefore, if the materials having the same tensile strength are compared with each other, the difference in workability between the materials can be easily determined.

Here, by evaluating the strength of the corresponding bent portion 17a of the bent sample piece 17, the strength characteristics of the spring portion 4c and the bent corner portion 4d in the corresponding connection terminals of the male terminal 2 and the female terminal 4 are obtained. Thus, relative evaluation can be easily performed. By feeding this back to the design of the connection terminal, it is possible to easily select a material having a desired strength, that is, a desired durability, and determine processing conditions. The enormous cost and time required for confirmation can be reduced.

FIG. 5 shows a second embodiment of the evaluation data measuring jig 10, in which the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

That is, in the present embodiment, the two load acting bodies 12 and 13 are of a movable type capable of moving close to and away from each other. In this case, when measuring the deformation displacement amount d, it is necessary to detect the movement amount of both the load applying bodies 12 and 13. Further, a posture holding unit that holds the sample piece 17 in a predetermined posture by the inclined opposing surfaces 12a and 13a of both the load applying bodies 12 and 13 is configured.

FIG. 6 shows a third embodiment of the jig 10 for measuring evaluation data. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

That is, in the first and second embodiments, the load is applied to the sample piece 17 by the load applying bodies 12 and 13 in a surface contact state. The load is applied to both sides of the sample piece 17 near the corresponding bent portion 17a in a line contact state in the width direction by the fixed-side load acting body 12 and the movable-side load acting body 13.

FIG. 7 shows a fourth embodiment of the evaluation data measuring jig 10, in which the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

That is, in the present embodiment, the structure in which the two load acting bodies 12, 13 are moved toward and away from each other by the forward / reverse rotation operation of the movable side load acting body 13 around the corresponding bending portion 17a. It has been.

It is to be noted that the two load acting bodies 12, 13 are moved closer to and away from each other in a linear direction as in the first to third embodiments, and are rotated in an arc shape as in the fourth embodiment. It is known by CAE analysis that the strength can be measured in the corresponding bending portion 17a in some cases.

In each of the above embodiments, the connection terminal is exemplified as the bent product. However, the present invention is not limited to the connection terminal and may be used for evaluating the strength of various products obtained by bending a metal plate member.

The bending angle θ of the test piece 17 that can be evaluated is
May be in the range of 0 ° <θ <180 °, and 4
A range of about 5 degrees ≦ θ ≦ 135 degrees is preferable. If the strength of a bent portion such as the spring portion 4c or the bent corner portion 4d is to be evaluated, a specific type of bending angle θ may be used, and the connection terminal material is the most standard bending process. What is necessary is just to employ bending processing of θ = 90 degrees. further,
If an angle of bending corresponding to an actual use situation is adopted, it is possible to obtain a more realistic evaluation of strength.

The thickness t of the specimen 17, the bending radius R,
The bending angle θ and the like are not limited to the above-described embodiment, and may be appropriately set as needed. If various data described above are measured for various materials that may be used as the material of the sample piece 17, There is an advantage that it is easy to select a material suitable for the purpose of use, a material such as a plate thickness t, a bending radius R and the like, and to select a processing condition.

Further, a structure is shown in which the movable-side load acting body 13 is pushed by manually screwing the operation screw shaft 14, but the movable-side load acting body 13 is automatically utilized by using a motor or the like. May be pressed.

The displacement detector is also provided with a micrometer 15.
However, the present invention is not limited to this, and may have a structure in which the movement amount of the movable-side load acting body 13 is electrically detected by a sensor or the like.

[0046]

As described above, according to the method for evaluating the strength of a bent portion according to the present invention, an elongated plate-shaped sample piece having a corresponding bent portion bent at an intermediate portion in the same manner as a bent product is obtained. , Load from both sides near the corresponding bending part,
The deformation angle in the load direction in the vicinity of the corresponding bending part until the inside angle of the corresponding bending part is gradually reduced in a direction in which the inside angle of the corresponding bending part becomes smaller, and until damage such as a crack or breakage of the corresponding bending part occurs. Is a method of evaluating the strength of the bent portion by the magnitude of the amount of deformation displacement,
The strength of the bent portion of the bent product, that is, the durability against displacement, can be easily evaluated at the corresponding bent portion of the sample piece, and here, a great deal of time and cost are required as in the conventional case. There is an advantage that selection of a material suitable for use conditions and selection of processing conditions can be easily performed without spending time.

In the case where the bent product is a connection terminal, there is no need to manufacture various male terminals and female terminals according to various materials and various processing conditions to confirm the appropriateness as in the related art. In addition, there is an advantage that it is possible to easily select a material and a processing condition suitable for use conditions.

According to the evaluation data measuring jig used in the method for evaluating the strength of a bent portion of the present invention, a posture holding portion for holding a sample piece in a predetermined posture; A load acting body disposed opposite to apply a load from both sides in the vicinity of the corresponding bending section, a load acting body moving section that moves both load acting bodies toward and away from each other in the load direction, and the deformation displacement amount. It is provided with a displacement detector that detects the amount of movement of the load acting body to detect the load.The load can be applied while the sample piece is held by the posture holder, and stable deformation displacement measurement can be performed. There is an advantage that it can be performed.

Further, one of the opposed load acting members is mounted and fixed on the substrate, and the other load acting member is supported on the substrate so as to be reciprocally movable in the load direction. The opposing surfaces of the body opposing each other are inclined opposing surfaces that gradually expand in a downward direction corresponding to the inclination along the extending direction of each of the extension pieces on both sides of the corresponding bending portion of the sample piece, The posture holding unit includes a fixing plate detachably attached to and fixed to the inclined opposing surface so as to fix and hold one of the extending pieces on the inclined opposing surface of the load acting body fixed and attached. The displacement amount detector is configured to be mounted and supported on the substrate side so as to detect the amount of movement of the load acting body supported to be reciprocally movable, so that the sample piece is held between the inclined opposing surface and the fixed plate. Fixing the sample piece in a more stable shape In can hold, also may be detecting the movement amount of the load introduction body detected one movable side deformation displacement has the advantage that the measurement can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an evaluation data measuring jig according to a first embodiment of the present invention.

FIG. 2 is a sectional front view of the same part.

FIG. 3 is a partial front view of a sample piece.

FIG. 4 is a diagram showing the relationship between tensile strength and deformation displacement.

FIG. 5 is an explanatory view showing a second embodiment of the evaluation data measuring jig.

FIG. 6 is an explanatory view showing a third embodiment of an evaluation data measuring jig.

FIG. 7 is an explanatory diagram showing a fourth embodiment of an evaluation data measuring jig.

FIG. 8 is an explanatory diagram showing a connection state between a male terminal and a female terminal.

FIG. 9 is an explanatory diagram of a spring portion of the female terminal.

FIG. 10 is a sectional view of the female terminal taken along line XX in FIG. 8;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Evaluation data measurement jig 11 Substrate 12 Fixed-side load acting body 12a Slope facing surface 13 Movable load acting body 13a Slant facing surface 14 Operation screw shaft 15 Micrometer 17 Sample piece 17a Corresponding bending part 17b Extension piece part 19 Fixing plate 22 Support block

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jin Kawabe 1-14 Nishisuehirocho, Yokkaichi-shi, Mie F-term in Sumitomo Wiring Systems Co., Ltd. (Reference) 2G061 AA07 AB03 BA01 CA01 CB02 DA16 EA02 EB10 3C020 XX00

Claims (4)

[Claims] 1. A method for evaluating the strength of a bent portion of a bent product obtained by bending a plate-like member, wherein the strength of the bent portion is the same as that of the bent product. A load is applied from both sides in the vicinity of the corresponding bent portion to gradually deform the elongated plate-shaped sample piece having the corresponding bent portion in a direction in which the inside angle of the corresponding bent portion becomes smaller. Measure the amount of deformation displacement in the load direction in the vicinity of the bending part corresponding to the occurrence of damage such as a crack or breakage of the processing part, and evaluate the strength of the bending part based on the magnitude of the deformation displacement. A method for evaluating the strength of a bent part characterized by the following. 2. The method according to claim 1, wherein the bent product is a connection terminal. 3. An evaluation data measuring jig for deforming the sample piece by applying the load in the method for evaluating strength of a bent portion according to claim 1, wherein the jig is held in a predetermined attitude. Part, a load acting body opposing to apply a load from both sides in the vicinity of the corresponding bending part of the sample piece held in the posture, and a load action for moving both load acting bodies toward and away from each other in the load direction. An evaluation data measuring jig, comprising: a body moving unit; and a displacement amount detecting unit that detects a moving amount of the load acting body to detect the deformation displacement amount. 4. One of the opposed load acting bodies is mounted and fixed on a substrate, and the other load acting body is supported on the substrate so as to be reciprocally movable in the load direction,
The opposing surfaces of both load acting bodies opposing each other are inclined opposing surfaces that gradually expand in a downward direction corresponding to the inclination along the extending direction of each of the extension pieces on both sides of the corresponding bending portion of the sample piece. And a fixing plate detachably attached and fixed to the inclined opposing surface so as to fix and hold one of the extension pieces on the inclined opposing surface of the load acting body fixedly attached. 4. The evaluation data measurement device according to claim 3, wherein the displacement amount detection unit is mounted and supported on the substrate side so as to detect a movement amount of the load acting body supported so as to be able to reciprocate. Jig.