JP2018116055A

JP2018116055A - Thermal fatigue test device and thermal fatigue test method using the same

Info

Publication number: JP2018116055A
Application number: JP2018003574A
Authority: JP
Inventors: 善宏石川; Yoshihiro Ishikawa; 友浩光井; Tomohiro Mitsui; 小川　澄雄; Sumio Ogawa; 澄雄小川
Original assignee: Sango Co Ltd
Current assignee: Sango Co Ltd
Priority date: 2017-01-16
Filing date: 2018-01-12
Publication date: 2018-07-26
Anticipated expiration: 2038-01-12
Also published as: JP6741700B2

Abstract

PROBLEM TO BE SOLVED: To provide a thermal fatigue test device which is made compact and inexpensive and a thermal fatigue test method using the same.SOLUTION: There is provided a thermal fatigue test device 1 for measuring thermal fatigue characteristics of a test piece 2 formed of one or plural plate-shaped metal members, in which the test piece 2 has an apex 3 in which strain concentrates when thermal fatigue characteristics are measured, and the device comprises: a restraining part 10 for restraining one end part 5a of the test piece 2; a grip part 11 for gripping the other end part 5b of the test piece 2; and a load measurement part 13 which is in linkage with the grip part 11. The load measurement part 13 measures a load which is generated when the test piece 2 is stretched and shrunk by temperature change, has at least one planar heating part 15, and one heating part is provided on an axial center part of the test piece 2 so as to be separated from the apex 3, and a thermal fatigue test method using the same is also provided.SELECTED DRAWING: Figure 2

Description

本発明は、熱疲労試験装置及びそれを用いた熱疲労試験方法に関する。 The present invention relates to a thermal fatigue test apparatus and a thermal fatigue test method using the same.

近年、エキゾーストマニホールド等の自動車用部品は、燃費改善の目的で軽量化が求められており、薄板材料で構成されることが多い。エキゾーストマニホールド等は、短時間で温度変化が激しい環境下で用いられるために、これらの部品には、優れた耐久性能が求められる。耐久性能を確認するためには、実際の部品を用いて耐久試験を行う必要があるが、この耐久試験には高額な費用がかかるため、熱応力解析等の計算により、耐久試験を行う前に耐久性能の目途付けが行われている。 In recent years, automotive parts such as exhaust manifolds have been required to be light in weight for the purpose of improving fuel efficiency, and are often made of thin plate materials. Since the exhaust manifold and the like are used in an environment where the temperature change is severe in a short time, these parts are required to have excellent durability performance. In order to check the durability performance, it is necessary to conduct an endurance test using actual parts. However, since this endurance test is expensive, before performing the endurance test by calculation such as thermal stress analysis Aiming for durability performance.

この熱応力解析等においては、部品における各部位の温度と、部品に用いる材料の熱疲労特性が必要となる。 In this thermal stress analysis or the like, the temperature of each part in the part and the thermal fatigue characteristics of the material used for the part are required.

部品における各部位の温度は、その部品を用いる車両の走行条件を想定し、実際にその走行条件で走行して、部品の各温度を測定して取得する。 The temperature of each part in the part is obtained by measuring the temperature of each part by actually traveling under the traveling condition assuming the traveling condition of the vehicle using the part.

材料の熱疲労特性を知るために、従来、円柱状の丸棒を用いて熱疲労試験を行い取得していた。しかし、目途付けを行うエキゾーストマニホールド等は、薄板材料を用いて構成されるため、熱疲労試験は、薄板材料を用いて行うことが望ましい。 In order to know the thermal fatigue characteristics of a material, a thermal fatigue test was conventionally performed using a cylindrical round bar. However, since the exhaust manifold or the like for making a plan is configured using a thin plate material, it is desirable to perform the thermal fatigue test using the thin plate material.

この薄板状の試験片を用いて熱疲労試験を行う熱疲労試験装置として、頂部を有するように山形に湾曲させた薄板状の試験片を用い、この頂部の周囲に高周波誘導加熱コイルを巻設して、この高周波誘導加熱コイルに電流を流すことで、試験片に高周波誘導加熱を行い、熱疲労試験を行う熱疲労試験装置が知られている（特許文献１参照）。 As a thermal fatigue test apparatus that performs thermal fatigue tests using this thin plate-shaped test piece, a thin plate-shaped test piece curved in a mountain shape so as to have a top portion is used, and a high frequency induction heating coil is wound around the top portion. A thermal fatigue test apparatus is known in which a high-frequency induction heating is performed on a test piece by flowing a current through the high-frequency induction heating coil to perform a thermal fatigue test (see Patent Document 1).

特開２０１５−２１９２１０号公報JP 2015-219210 A

上記従来の熱疲労試験は、高周波誘導加熱装置により試験片を加熱しているため、熱疲労試験装置が大型化するとともに、その価格も高価なものとなった。 In the conventional thermal fatigue test, since the test piece is heated by the high frequency induction heating device, the thermal fatigue test device is enlarged and the price is also expensive.

また、鋼材の熱疲労特性は、温度により特性が変わるため、複数の温度条件において試験を行う必要がある。また、１つの材料の試験には約５４ヶ月必要となり、同時に多数の試験を並行して行うことが望まれるが、上記の熱疲労試験装置の台数を多くそろえることは、設置場所や費用の点で困難であった。 Moreover, since the thermal fatigue characteristics of steel materials change depending on the temperature, it is necessary to perform tests under a plurality of temperature conditions. In addition, it takes about 54 months to test one material, and it is desirable to perform many tests at the same time. However, increasing the number of thermal fatigue test devices mentioned above is a matter of installation location and cost. It was difficult.

エキゾーストマニホールドなどの自動車用部品は、開発期間が短いため、従来の試験方法では、熱疲労試験が間に合わないことがあり、最適な材料を選択できない場合には、オーバースペックで高価な材料を用いざるを得なかった。 Since automotive parts such as exhaust manifolds have a short development period, thermal fatigue testing may not be in time with conventional test methods, and if the optimal material cannot be selected, overspec and expensive materials must be used. Did not get.

そこで、本発明は、装置を小型化できるとともに、安価な熱疲労試験装置及びそれを用いた熱疲労試験方法を提案することを目的とするものである。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to propose an inexpensive thermal fatigue test apparatus and a thermal fatigue test method using the apparatus that can reduce the size of the apparatus.

前記の課題を解決するために、本発明は、一枚又は複数枚の板状の金属製の部材で構成された試験片の熱疲労特性を測定する熱疲労試験装置であって、
前記試験片は、熱疲労特性を測定する際にひずみが集中する頂部を有し、
前記試験片の一端部を拘束する拘束部と、前記試験片の他端部を把持する把持部と、該把持部と連動する荷重測定部を備え、
該荷重測定部は、温度変化により、前記試験片が伸縮することで生じる荷重を測定し、
少なくとも１つ以上の面状の加熱部を有し、その一の加熱部を、前記試験片の軸方向中央部に、前記頂部から離間するように設けたことを特徴とする熱疲労試験装置である。 In order to solve the above problems, the present invention is a thermal fatigue test apparatus for measuring thermal fatigue characteristics of a test piece composed of one or more plate-shaped metal members,
The test piece has a top where strain is concentrated when measuring thermal fatigue properties,
A restraining portion for restraining one end portion of the test piece, a gripping portion for gripping the other end portion of the test piece, and a load measuring portion interlocking with the gripping portion,
The load measuring unit measures a load generated by expansion and contraction of the test piece due to temperature change,
A thermal fatigue testing apparatus comprising at least one planar heating unit, wherein one heating unit is provided at a central portion in the axial direction of the test piece so as to be separated from the top. is there.

また、前記試験片を、一枚の金属製の平板を、その厚み方向に屈曲させることにより、前記平板の中央部に、前記頂部を形成してもよい。 Moreover, you may form the said top part in the center part of the said flat plate by bending the said test piece in the thickness direction of one metal flat plate.

また、前記試験片を、複数枚の板状の金属製の部材で構成し、その部材相互を溶接により接合して、この溶接部分を前記頂部としてもよい。 Further, the test piece may be composed of a plurality of plate-shaped metal members, the members are joined to each other by welding, and the welded portion may be the top portion.

また、少なくとも３つ以上の面状の加熱部を有し、その加熱部を、前記試験片の軸方向において、前記頂部の両側部に、夫々、前記試験片から離間するように設けてもよい。 Further, at least three or more planar heating portions may be provided, and the heating portions may be provided on both sides of the top in the axial direction of the test piece so as to be separated from the test piece, respectively. .

また、前記把持部は、規制部により、前記試験片の軸方向のみに移動できるようにしてもよい。 Further, the gripping part may be movable only in the axial direction of the test piece by the restricting part.

また、前記試験片及び前記加熱部の少なくとも一部を遮蔽部材で覆ってもよい。 Moreover, you may cover at least one part of the said test piece and the said heating part with a shielding member.

また、前記頂部を指向する冷却部を設けてもよい。 Moreover, you may provide the cooling part which faces the said top part.

また、一枚又は複数枚の板状の金属製の部材で構成された試験片の熱疲労特性を測定し、
前記試験片は、熱疲労特性を測定する際にひずみが集中する頂部を有し、
前記試験片の一端部を拘束する拘束部と、前記試験片の他端部を把持する把持部と、該把持部と連動する荷重測定部を備え、
該荷重測定部は、温度変化により、前記試験片が伸縮することで生じる荷重を測定し、
少なくとも１つ以上の面状の加熱部を有し、その一の加熱部を、前記試験片の軸方向中央部に、前記頂部から離間するように設けた熱疲労試験装置を用いて、
試験片に対し、所定加熱温度までの加熱と所定冷却温度までの冷却を繰り返し行い、１回の加熱と１回の冷却を１サイクルとし、この１サイクルにおける荷重の最大値が、一度の熱疲労試験全体における荷重最大値に対し、初めて所定の割合以下となった際のサイクル数を、前記試験を行った際の所定加熱温度におけるその試験片の耐久限界とすることを特徴とする熱疲労試験方法である。 In addition, the thermal fatigue characteristics of a test piece composed of one or more plate-like metal members are measured,
The test piece has a top where strain is concentrated when measuring thermal fatigue properties,
A restraining portion for restraining one end portion of the test piece, a gripping portion for gripping the other end portion of the test piece, and a load measuring portion interlocking with the gripping portion,
The load measuring unit measures a load generated by expansion and contraction of the test piece due to temperature change,
Using a thermal fatigue testing apparatus having at least one or more planar heating parts, the one heating part being provided in the axially central part of the test piece so as to be separated from the top part,
The test piece is repeatedly heated to a predetermined heating temperature and cooled to a predetermined cooling temperature, and one heating and one cooling are defined as one cycle, and the maximum value of the load in this cycle is one thermal fatigue. Thermal fatigue test, characterized in that the number of cycles when the ratio falls below a predetermined ratio for the first time with respect to the maximum load value in the entire test is the endurance limit of the test piece at the predetermined heating temperature when the test is performed Is the method.

また、前記熱疲労試験方法を複数回行い、前記試験を行った際の所定加熱温度における、その試験片の耐久限界と、その耐久限界を測定した際の熱歪量との関係式を得てもよい。 Further, the thermal fatigue test method is performed a plurality of times, and the relational expression between the endurance limit of the test piece at the predetermined heating temperature when the test is performed and the amount of thermal strain when the endurance limit is measured is obtained. Also good.

また、異なる所定加熱温度において、前記関係式を得てもよい。 Further, the relational expression may be obtained at different predetermined heating temperatures.

本発明は、試験片の一端を拘束する拘束部と、試験片の他端を把持する把持部と、該把持部と連動する荷重測定部を備え、荷重測定部は、温度変化により、試験片が伸縮することで生じる荷重を測定し、少なくとも１つ以上の面状の加熱部を有し、その一の加熱部を前記頂部から離間して設けたことにより、熱疲労試験装置を小型化できるとともに、安価に製造することができる。これにより、熱疲労試験装置を多数設置することが容易となり、熱疲労試験を同時に多数行うことができ熱疲労試験の時間を短縮でき、自動車用部品に用いる最適な材料の選定が行いやすくなる。 The present invention includes a restraining portion that restrains one end of a test piece, a gripping portion that grips the other end of the test piece, and a load measuring portion that works in conjunction with the gripping portion. The thermal fatigue test apparatus can be miniaturized by measuring the load generated by the expansion and contraction of at least one, and having at least one or more planar heating parts, and providing one heating part apart from the top part. At the same time, it can be manufactured at low cost. Thereby, it becomes easy to install a large number of thermal fatigue test apparatuses, a large number of thermal fatigue tests can be performed at the same time, the time of the thermal fatigue test can be shortened, and it becomes easy to select an optimal material used for automobile parts.

本発明の実施例１に係る熱疲労試験装置の上面図。1 is a top view of a thermal fatigue test apparatus according to Embodiment 1 of the present invention. 図１のＡ−Ａ線断面図。AA sectional view taken on the line AA of FIG. 本発明の実施例１における熱疲労試験の温度変化を示すグラフ。The graph which shows the temperature change of the thermal fatigue test in Example 1 of this invention. 図３における熱荷重の変化を示すグラフ。The graph which shows the change of the thermal load in FIG. １サイクルにおける温度と熱荷重との関係を示すグラフ。The graph which shows the relationship between the temperature and thermal load in 1 cycle. 各サイクル数の熱荷重最大値変化を示すグラフ。The graph which shows the thermal load maximum value change of each cycle number. 耐久限界と熱歪量との関係を示す熱疲労特性の関係式。A relational expression of thermal fatigue characteristics showing the relationship between the endurance limit and the amount of thermal strain. 本発明の実施例２に係る熱疲労試験装置の断面図。Sectional drawing of the thermal fatigue testing apparatus which concerns on Example 2 of this invention. 本発明の実施例３に用いる試験片の一例の正面図。The front view of an example of the test piece used for Example 3 of this invention. 本発明の実施例３に用いる試験片の他例の正面図。The front view of the other example of the test piece used for Example 3 of this invention. 本発明の実施例３に用いる試験片の他例の正面図。The front view of the other example of the test piece used for Example 3 of this invention. 本発明の実施例３に用いる試験片の他例の正面図。The front view of the other example of the test piece used for Example 3 of this invention. 本発明の実施例３に用いる試験片の他例の正面図。The front view of the other example of the test piece used for Example 3 of this invention. 本発明の実施例３に用いる試験片の他例の正面図。The front view of the other example of the test piece used for Example 3 of this invention. 本発明の実施例４に係る熱疲労試験装置の一例の上面図。The top view of an example of the thermal fatigue testing apparatus which concerns on Example 4 of this invention. 図１５のＢ−Ｂ線断面図。BB sectional drawing of FIG. 本発明の実施例５に係る熱疲労試験装置の一例の断面図。Sectional drawing of an example of the thermal fatigue testing apparatus which concerns on Example 5 of this invention. 本発明の実施例５に係る熱疲労試験装置の他例の断面図。Sectional drawing of the other example of the thermal fatigue testing apparatus which concerns on Example 5 of this invention. 本発明の実施例６に係る熱疲労試験装置の上面図。The top view of the thermal fatigue testing apparatus which concerns on Example 6 of this invention. 図１９の横断面図。FIG. 20 is a cross-sectional view of FIG. 19. 図１９のＣ−Ｃ線断面図。The CC sectional view taken on the line of FIG. 本発明の実施例６に係る熱疲労試験装置の他例を示す部分縦断面図。The fragmentary longitudinal cross-section which shows the other example of the thermal fatigue testing apparatus which concerns on Example 6 of this invention. 本発明の実施例７に係る熱疲労試験装置を示す部分縦断面図。The fragmentary longitudinal cross-section which shows the thermal fatigue testing apparatus which concerns on Example 7 of this invention. 本発明の実施例８に係る熱疲労試験装置の一例を示す部分縦断面図。The fragmentary longitudinal cross-section which shows an example of the thermal fatigue testing apparatus which concerns on Example 8 of this invention.

本発明を実施するための形態を図に示す実施例に基づいて説明する。 A mode for carrying out the present invention will be described based on an embodiment shown in the drawings.

［実施例１］
図１は、本発明の実施例１に係る熱疲労試験装置１の上面図、図２は図１のＡ−Ａ線断面図を示す。 [Example 1]
FIG. 1 is a top view of a thermal fatigue test apparatus 1 according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

熱疲労試験装置１に用いる試験片２は、図１，図２に示すように、長尺の長方形状で、かつ、薄板状からなる一枚の金属製の部材を、その長手方向である軸方向において屈曲して形成され、軸方向の中央部において、厚み方向の一方向に突出するように、くさび状に屈曲された頂部３が形成されている。頂部３の軸方向における両側部には、平面状で、かつ、軸方向に対して傾くように形成された傾斜部４，４が形成されている。夫々の傾斜部４における軸方向の外側には、頂部３側に屈曲させて取付部５が形成されている。取付部５は、軸方向及び短手方向である幅方向にわたって平面状に形成されている。頂部３、傾斜部４、取付部５，５は、薄板状の部材を湾曲して一体に形成されている。 As shown in FIGS. 1 and 2, the test piece 2 used in the thermal fatigue test apparatus 1 has a long rectangular shape and a thin metal plate made of a single metal member having a longitudinal axis. A top portion 3 is formed that is bent in the direction, and is bent in a wedge shape so as to protrude in one direction in the thickness direction in the central portion in the axial direction. On both side portions of the top portion 3 in the axial direction, inclined portions 4 and 4 are formed which are planar and are inclined with respect to the axial direction. A mounting portion 5 is formed on the outer side of each inclined portion 4 in the axial direction by bending toward the top portion 3 side. The attachment portion 5 is formed in a planar shape over the width direction, which is the axial direction and the short direction. The top part 3, the inclined part 4, and the attachment parts 5 and 5 are integrally formed by bending a thin plate member.

試験片２の一方の取付部５の端部５ａ、すなわち試験片２の一端部５ａは、基部９に固定された拘束部１０により取外し可能に固定されている。試験片２の一端部５ａは、試験片２が、その温度変化により軸方向の長さが伸縮した際にも、基部９に対して動かないように固定、すなわち、基部９に対して移動不能に拘束されている。拘束部１０は、試験片２の一端部５ａを、試験片２が、その温度変化により軸方向にその長さが伸縮した際にも動かないように固定できれば任意の構造とすることができ、例えば、試験片２の屈曲方向（図２の上下方向）に移動若しくは分離できる２個のブロックで構成され、この２個のブロックにより、試験片２をその板厚方向において挟持し、ボルト等により２個のブロックを固定する。 An end portion 5 a of one attachment portion 5 of the test piece 2, that is, one end portion 5 a of the test piece 2 is detachably fixed by a restraining portion 10 fixed to the base portion 9. One end 5a of the test piece 2 is fixed so that the test piece 2 does not move relative to the base 9 even when the axial length of the test piece 2 expands or contracts due to the temperature change, that is, cannot move with respect to the base 9. It is restrained by. The restraining portion 10 can have an arbitrary structure as long as the one end 5a of the test piece 2 can be fixed so that the test piece 2 does not move even when the length of the test piece 2 expands or contracts in the axial direction due to the temperature change. For example, it is composed of two blocks that can be moved or separated in the bending direction of the test piece 2 (vertical direction in FIG. 2), the test piece 2 is sandwiched in the thickness direction by these two blocks, and bolts or the like are used. Fix two blocks.

試験片２の他方の取付部５の端部５ｂ、すなわち、試験片２の他端部５ｂは、スライドテーブル等からなる規制部１２により、基部９に対して試験片２の軸方向のみに移動可能に設けられた把持部１１に取付けられている。試験片２の他端部５ｂは、把持部１１に任意の方法により取外し可能に固定され、例えば、上記拘束部１０と同様の取付構造に構成されている。 The end portion 5b of the other mounting portion 5 of the test piece 2, that is, the other end portion 5b of the test piece 2 is moved only in the axial direction of the test piece 2 with respect to the base portion 9 by the restriction portion 12 made of a slide table or the like. It is attached to the grip portion 11 that is provided. The other end 5b of the test piece 2 is fixed to the grip 11 so as to be removable by an arbitrary method, and has, for example, an attachment structure similar to that of the restraint 10.

把持部１１における軸方向の外側には、ロードセル等からなる荷重測定部１３が接続され、荷重測定部１３は基部９に固設されている。荷重測定部１３は、熱疲労試験時に、試験片２が加熱若しくは冷却されて、その温度変化により、試験片２がその軸方向に伸縮することにより生じる荷重（以下、熱荷重という）を測定できるようになっている。把持部１１は、規制部１２により、試験片２の軸方向のみに移動可能に設けられていることで、把持部１１の軸方向以外への移動が規制され、熱荷重を、正確に測定することができる。 A load measuring unit 13 made of a load cell or the like is connected to the outside of the gripping unit 11 in the axial direction, and the load measuring unit 13 is fixed to the base 9. The load measuring unit 13 can measure a load (hereinafter referred to as a thermal load) generated when the test piece 2 is heated or cooled during the thermal fatigue test and the test piece 2 expands and contracts in the axial direction due to the temperature change. It is like that. The gripping part 11 is provided by the restriction part 12 so as to be movable only in the axial direction of the test piece 2, so that the movement of the gripping part 11 in a direction other than the axial direction is restricted, and the thermal load is accurately measured. be able to.

試験片２の凸部側（図２の上側）には、図１、図２に示すように、面状である平板状の加熱部１５が、試験片２の軸方向の中央部における頂部３の上方に１カ所、その両側部で両傾斜部４，４の上方に夫々１カ所、その両側部における取付部５，５の上方に夫々１カ所の計５か所に配置されているとともに、各加熱部１５の先部の発熱部１５ａは、図１に示すように、試験片２の軸方向と直交する方向に、試験片２の幅方向全体に亘って配設されている。また、夫々の加熱部１５の発熱部１５ａは、図２に示すように、試験片２の接平面若しくは平面と並行となるとともに、試験片２から所定距離離間して配置されている。この離間距離は、試験片２が、熱疲労試験における温度変化により変形した際に、加熱部１５に当接しない距離に設定するとともに、所定加熱温度に応じて任意に設定する。 On the convex side of the test piece 2 (upper side of FIG. 2), as shown in FIGS. 1 and 2, a flat plate-like heating unit 15 having a planar shape has a top 3 at the central portion in the axial direction of the test piece 2. 1 at the top, 1 on each side of the two inclined portions 4 and 4, respectively, and 1 on each of the mounting portions 5 and 5 on both sides. As shown in FIG. 1, the heating portion 15 a at the tip of each heating unit 15 is disposed across the entire width direction of the test piece 2 in a direction orthogonal to the axial direction of the test piece 2. Further, as shown in FIG. 2, the heating portions 15 a of the respective heating units 15 are arranged in parallel with the tangential plane or the plane of the test piece 2 and spaced apart from the test piece 2 by a predetermined distance. The separation distance is set to a distance that does not contact the heating unit 15 when the test piece 2 is deformed due to a temperature change in the thermal fatigue test, and is arbitrarily set according to a predetermined heating temperature.

このように、面状でかつ平板状の加熱部１５の発熱部１５ａが、試験片２の軸方向と直交する方向に、試験片２の幅方向全体に亘って配設されていることで、発熱部１５ａにより試験片２を加熱した際に、その試験片２における幅方向の温度変化を小さく抑えることができる。 In this way, the heating unit 15a of the planar and flat heating unit 15 is disposed across the entire width direction of the test piece 2 in a direction orthogonal to the axial direction of the test piece 2. When the test piece 2 is heated by the heat generating part 15a, the temperature change in the width direction of the test piece 2 can be suppressed to be small.

加熱部１５の発熱部１５ａは、面状に形成されていれば、任意の加熱部材を用いることができるが、セラミックヒータなどの輻射式加熱部材を用いることが好ましく、本実施例においては、セラミックヒータを用いた。発熱部１５ａを平面状とすることで、試験片２を広範囲に加熱することができ、試験片２の温度分布が、軸方向においてその変化がなだらかになるとともに、同一条件下で熱疲労試験を行った際の、試験片２の温度分布の再現性が良く、試験片２に生じる熱歪の量も近似した値となり、再現性の高い熱疲労試験を行うことができる。 Any heating member can be used as the heating unit 15a of the heating unit 15 as long as the heating unit 15 is formed in a planar shape. However, it is preferable to use a radiant heating member such as a ceramic heater. A heater was used. By making the heat generating part 15a flat, the test piece 2 can be heated in a wide range, the temperature distribution of the test piece 2 becomes gentle in the axial direction, and the thermal fatigue test is performed under the same conditions. The reproducibility of the temperature distribution of the test piece 2 during the test is good, the amount of thermal strain generated in the test piece 2 is also an approximate value, and a highly reproducible thermal fatigue test can be performed.

加熱部１５の試験片２に対する角度や離間距離は、図示しない調整手段により任意に変更することができるようになっている。これにより、熱疲労試験の際に、試験片２に生じる熱歪の量を変化させるために、試験片２の取付部５から頂部３までの高さ（山の高さ）や、頂部３の屈曲角度等を変化させることができ、試験片２の形状が変わった場合にも容易に対応することができるようになっている。 The angle and the separation distance of the heating unit 15 with respect to the test piece 2 can be arbitrarily changed by adjusting means (not shown). Thereby, in order to change the amount of thermal strain generated in the test piece 2 during the thermal fatigue test, the height (mountain height) from the mounting part 5 to the top part 3 of the test piece 2 or the top part 3 The bending angle or the like can be changed, and the case where the shape of the test piece 2 is changed can be easily handled.

また、試験片２の凹部側（図２の下側）には、図示しないエアブロー等の送風装置からなる冷却部が設けられている。なお、この冷却部は、試験片２の頂部３を指向して、頂部３を加熱後に冷却することができれば任意の手段を用いることができる。冷却部を設けることで、後述する熱疲労試験を行う際に、試験片２を急冷できる。エキゾーストマニホールド等の部品は短時間での温度変化が激しいため、実際の部品の使用条件に近い条件で熱疲労試験を行うことができるように、このような冷却部を設けることが好ましい。しかし、この冷却部を、設けなくてもよい。 In addition, a cooling unit made of a blower such as an air blower (not shown) is provided on the concave side of the test piece 2 (lower side in FIG. 2). In addition, this cooling part can point to the top part 3 of the test piece 2, and can use arbitrary means as long as the top part 3 can be cooled after heating. By providing the cooling unit, the test piece 2 can be rapidly cooled when a thermal fatigue test described later is performed. Since components such as the exhaust manifold undergo rapid temperature changes in a short time, it is preferable to provide such a cooling section so that a thermal fatigue test can be performed under conditions close to the actual usage conditions of the components. However, this cooling unit may not be provided.

次に、熱疲労試験装置１を用いた熱疲労試験方法について説明する。 Next, a thermal fatigue test method using the thermal fatigue test apparatus 1 will be described.

熱疲労試験装置１に試験片２を取付け、加熱部１５により、所定の加熱温度（例えば、８００℃）Ｔ１まで加熱し、所定加熱温度における試験片２の温度分布を測定する。また、この試験片２に用いる鋼材の高温引っ張り試験等を行う。 The test piece 2 is attached to the thermal fatigue test apparatus 1, heated to a predetermined heating temperature (for example, 800 ° C.) T1 by the heating unit 15, and the temperature distribution of the test piece 2 at the predetermined heating temperature is measured. Further, a high-temperature tensile test of the steel material used for the test piece 2 is performed.

これらの温度分布と高温引っ張り試験結果等を基にして、用いる試験片２の熱歪み量を算出する。 Based on these temperature distributions and high-temperature tensile test results, the amount of thermal strain of the test piece 2 to be used is calculated.

次に、この歪み量を算出した試験片とは異なるが、同じ素材、形状を有する試験片２を、熱疲労試験装置１の拘束部１０と把持部１１に取付ける。 Next, the test piece 2 having the same material and shape is attached to the restraining portion 10 and the gripping portion 11 of the thermal fatigue test apparatus 1 although it is different from the test piece for which the strain amount is calculated.

次に、加熱部１５により、ひずみが集中する試験片２の頂部３を、図３に示すように、所定加熱温度Ｔ１となるまで加熱し、その所定加熱温度Ｔ１を所定時間保持する。なお、頂部３には、図示しない温度センサが取り付けられており、この温度センサにより頂部３の温度を計測することができるようになっている。加熱部１５に輻射式の加熱部材を用いた場合には、頂部３、凸部側面から凹部側面にかけての厚み方向全体の温度を短時間で所定加熱温度Ｔ１まで加熱することができる。 Next, as shown in FIG. 3, the top 3 of the test piece 2 where strain is concentrated is heated by the heating unit 15 until a predetermined heating temperature T1 is reached, and the predetermined heating temperature T1 is held for a predetermined time. Note that a temperature sensor (not shown) is attached to the top 3, and the temperature of the top 3 can be measured by this temperature sensor. When a radiation-type heating member is used for the heating unit 15, the temperature in the entire thickness direction from the top 3, the convex side surface to the concave side surface can be heated to the predetermined heating temperature T1 in a short time.

次に、加熱部１５による加熱を停止し、冷却部により冷却を行い、図３に示すように、試験片２の頂部３を所定冷却温度（例えば、２００℃）Ｔ２より上の温度（例えば、２５０℃）となるまで冷却し、その後、冷却部による冷却を停止し、自然冷却により所定冷却温度Ｔ２となるまで冷却を行う。所定冷却温度Ｔ２に達したら、その所定冷却温度Ｔ２を所定時間保持する。これにより１サイクルが完了する。この１サイクルの間、荷重測定部１３により熱荷重を測定する。 Next, heating by the heating unit 15 is stopped, cooling is performed by the cooling unit, and as shown in FIG. 3, the top 3 of the test piece 2 is heated to a temperature (for example, 200 ° C.) above a predetermined cooling temperature (for example, 200 ° C.) 250 ° C.), then cooling by the cooling unit is stopped, and cooling is performed by natural cooling until a predetermined cooling temperature T 2 is reached. When the predetermined cooling temperature T2 is reached, the predetermined cooling temperature T2 is held for a predetermined time. This completes one cycle. During this one cycle, the load measuring unit 13 measures the thermal load.

この１サイクルの後に、再度、加熱部１５により加熱を開始し、上記と同じ１サイクルを繰り返す。 After this one cycle, the heating unit 15 starts heating again, and the same one cycle as described above is repeated.

試験片２は加熱部１５による加熱により熱膨張する。試験片２の一方の端部５ａは拘束部１０により拘束されているため、試験片２の他端部５ｂ側に伸長し、把持部１１が外側方向に移動し、荷重測定部１３には圧縮荷重が加わり、図４に示すように、熱荷重が徐々に減少する。次に、試験片２が冷却されると収縮し、拘束部１０側に収縮し、把持部１１が内側方向に移動し、荷重測定部１３には伸長荷重が加わり、図４に示すように、熱荷重が徐々に増大する。 The test piece 2 is thermally expanded by heating by the heating unit 15. Since one end portion 5a of the test piece 2 is restrained by the restraining portion 10, it extends to the other end portion 5b side of the test piece 2, the gripping portion 11 moves outward, and the load measuring portion 13 is compressed. A load is applied, and the thermal load gradually decreases as shown in FIG. Next, when the test piece 2 is cooled, it contracts, contracts to the restraining part 10 side, the gripping part 11 moves inward, an extension load is applied to the load measuring part 13, and as shown in FIG. Thermal load increases gradually.

このように、上記の加熱と冷却からなる１サイクルを繰り返すことにより、荷重測定部１３では、図５に示すような温度変化により圧縮荷重と伸長荷重が交互に繰り返される。１サイクル内における所定冷却温度Ｔ２における熱荷重Ｎは、サイクル数が大きくなるとともに、図６に示すように徐々に減少する。あるサイクル数における熱荷重の最大値が、１度の熱疲労試験全体における熱荷重の最大値に対して、最初に所定の割合以下となった場合に、そのサイクル数を、所定加熱温度における試験片の耐久限界（熱疲労寿命ともいう）と認定する。 Thus, by repeating one cycle consisting of the above heating and cooling, the load measuring unit 13 alternately repeats the compression load and the extension load due to the temperature change as shown in FIG. The thermal load N at the predetermined cooling temperature T2 within one cycle gradually decreases as shown in FIG. 6 as the number of cycles increases. When the maximum value of the thermal load at a certain cycle number initially falls below a predetermined ratio with respect to the maximum value of the thermal load in one entire thermal fatigue test, the cycle number is tested at the specified heating temperature. Approved as the endurance limit of the piece (also called thermal fatigue life).

この熱疲労試験装置１を用いて同じ温度条件で上記熱疲労試験を複数回行う。本実施例においては２〜３回実施する。そして、異なる熱歪み量となるように、試験片２の高さ（山の高さ）や、頂部３の屈曲角度等を変化させて、例えば、３つの異なる形状の試験片を用いて、同じ所定加熱温度において、熱疲労試験を行うと、図７に示すように、試験片に用いた金属（鋼材）の所定加熱温度（例えば、８００℃）における耐久限界と熱歪量との関係を示す熱疲労特性の関係式を得ることができる。 Using the thermal fatigue test apparatus 1, the thermal fatigue test is performed a plurality of times under the same temperature conditions. In this embodiment, it is carried out 2 to 3 times. Then, by changing the height (mountain height) of the test piece 2 and the bending angle of the top 3 so as to have different amounts of thermal strain, for example, using the test pieces of three different shapes, the same When a thermal fatigue test is performed at a predetermined heating temperature, as shown in FIG. 7, the relationship between the durability limit and the amount of thermal strain at a predetermined heating temperature (for example, 800 ° C.) of the metal (steel material) used for the test piece is shown. A relational expression of thermal fatigue characteristics can be obtained.

更に、エキゾーストマニホールド等の自動車用部品を取付けた車両の走行条件において、実際に自動車用部品に生じた温度範囲内において、所定加熱温度を変化させて、例えば、７００℃、９００℃に変化させて、同様の熱疲労試験を行い、図７に示すように、試験片に用いた金属（鋼材）の夫々の温度における耐久限界と熱歪量との関係を示す熱疲労特性の関係式を得る。 Furthermore, in the running condition of the vehicle to which the automobile parts such as the exhaust manifold are attached, the predetermined heating temperature is changed within the temperature range actually generated in the automobile parts, for example, 700 ° C. and 900 ° C. Then, the same thermal fatigue test is performed, and as shown in FIG. 7, a relational expression of thermal fatigue characteristics indicating the relationship between the durability limit at each temperature and the amount of thermal strain of the metal (steel material) used for the test piece is obtained.

実際に測定した部品の各部位の温度を基にして、部品の熱応力解析を行って熱ひずみ量を算出し、図７に示す熱疲労特性を使って、耐久試験の目途付けを行うことができる。また、様々な金属での熱疲労特性を得ておくことで、部品に要求される使用サイクル等に応じて、部品に最適な金属材料を選定することができる。 Based on the actual measured temperature of each part of the part, thermal stress analysis of the part is performed to calculate the amount of thermal strain, and the endurance test can be made using the thermal fatigue characteristics shown in FIG. it can. In addition, by obtaining thermal fatigue characteristics of various metals, it is possible to select an optimal metal material for the part according to the use cycle required for the part.

本発明の熱疲労試験装置１は、試験片２から離間して設けられているとともに、面状に形成された加熱部１５を用いて試験片２を加熱するようにしたことにより、上記従来の高周波誘導加熱や電気抵抗式の加熱手段を用いて試験片を加熱するものと比較して、構造を簡略化でき小型化できるとともに、製造コストを低く抑えることができる。これにより、多数の熱疲労試験装置１を購入、設置しやすくなり、熱疲労試験を同時に多数行うことができ、熱疲労試験にかかる時間を短縮でき、自動車用部品に最適な材料を選択できる。 The thermal fatigue test apparatus 1 of the present invention is provided apart from the test piece 2 and heats the test piece 2 by using a heating portion 15 formed in a planar shape, so that The structure can be simplified and the size can be reduced, and the manufacturing cost can be reduced as compared with the case where the test piece is heated using high-frequency induction heating or electric resistance heating means. Thereby, it becomes easy to purchase and install a large number of thermal fatigue test apparatuses 1, a large number of thermal fatigue tests can be performed at the same time, the time required for the thermal fatigue test can be shortened, and the most suitable material for automobile parts can be selected.

［実施例２］
上記実施例１においては、試験片２を、薄板状からなる一枚の金属製の部材を、その厚み方向に屈曲して形成したが、長尺の長方形状で、かつ、で薄板状からなる金属製の板状部材３０，３１を、二枚溶接により接合して試験片３２として用いてもよい。 [Example 2]
In Example 1 described above, the test piece 2 was formed by bending a thin metal member in the thickness direction, but it was a long rectangular shape and a thin plate shape. The metal plate-like members 30 and 31 may be joined as a test piece 32 by welding two pieces.

第１の板状部材３０は、図８に示すように、長尺で薄板状からなる一枚の金属製の部材を、その厚み方向に屈曲して一体に形成されている。第１の板状部材３０は、軸方向及び短手方向である幅方向にわたって平面状に形成された取付部３３を有し、取付部３３における第２の板状部材３１側（長手方向である軸方向の内側）には、取付部３３に対して傾くように形成された平面状の傾斜部３４が設けられ、傾斜部３４における軸方向の内側には、取付部３３と略平行に形成された平面状の係合部３５が設けられている。 As shown in FIG. 8, the first plate member 30 is integrally formed by bending a long and thin plate-like metal member in the thickness direction. The first plate-shaped member 30 has a mounting portion 33 formed in a planar shape over the width direction that is the axial direction and the short direction, and the second plate-shaped member 31 side (longitudinal direction) in the mounting portion 33. A flat inclined portion 34 formed to be inclined with respect to the attachment portion 33 is provided on the inner side in the axial direction, and is formed substantially parallel to the attachment portion 33 on the inner side in the axial direction of the inclined portion 34. Further, a flat engaging portion 35 is provided.

第２の板状部材３１は、図８に示すように、長尺で薄板状からなる一枚の金属製の部材を、その厚み方向に屈曲して一体に形成されている。第２の板状部材３１は、軸方向及び短手方向である幅方向にわたって平面状に形成された取付部３７を有し、取付部３７における第１の板状部材３０側（軸方向の内側）には、取付部３７に対して傾くように形成された平面状の傾斜部３８が設けられ、傾斜部３８における軸方向の内側には、取付部３７と略平行に形成された平面状の係合部３９が設けられている。 As shown in FIG. 8, the second plate member 31 is integrally formed by bending a long and thin plate-like metal member in the thickness direction. The second plate-shaped member 31 has a mounting portion 37 formed in a planar shape over the width direction that is the axial direction and the short direction, and the first plate-shaped member 30 side (in the axial direction inside) of the mounting portion 37. ) Is provided with a flat inclined portion 38 formed so as to be inclined with respect to the attachment portion 37, and a planar shape formed substantially parallel to the attachment portion 37 on the inner side in the axial direction of the inclined portion 38. An engaging portion 39 is provided.

第１の板状部材３０と第２の板状部材３１は、その軸方向と直交する短手方向（幅方向）の長さが、略同じになるように形成されている。 The first plate-like member 30 and the second plate-like member 31 are formed so that the lengths in the short direction (width direction) orthogonal to the axial direction are substantially the same.

第１の板状部材３０と第２の板状部材３１は、図８に示すように、軸方向において、対向するように配置され、第１の板状部材３０における係合部３５の上方に、第２の板状部材３１の係合部３９の一部が重なるように重ね合されて、第２の板状部材３１の内側端部と、第１の板状部材３０の係合部３５の平面部を、その軸方向と直交する短手方向全体に亘って、隅肉溶接した溶接部４０により接合している。 As shown in FIG. 8, the first plate-like member 30 and the second plate-like member 31 are arranged so as to face each other in the axial direction, and above the engaging portion 35 in the first plate-like member 30. The second plate-like member 31 is overlapped so that a part of the engaging portion 39 overlaps, and the inner end portion of the second plate-like member 31 and the engaging portion 35 of the first plate-like member 30 are overlapped. These flat portions are joined by a fillet welded welded portion 40 over the entire lateral direction perpendicular to the axial direction.

金属製の板状部材３０，３１は、任意の金属で構成することができ、第１の板状部材３０と第２の板状部材３１を、同じ金属で構成してもよいし、異なる金属で構成してもよい。例えば、第１の板状部材３０を、フェライトＳＵＳ材で構成し、第２の板状部材３１をオーステナイト系ＳＵＳ材で構成してもよい。 The metal plate-like members 30 and 31 can be made of any metal, and the first plate-like member 30 and the second plate-like member 31 may be made of the same metal or different metals. You may comprise. For example, the first plate member 30 may be made of a ferrite SUS material, and the second plate member 31 may be made of an austenitic SUS material.

溶接部４０は、第１の板状部材３０における傾斜部３４と係合部３５間の屈曲部と、第２の板状部材３１における傾斜部３８と係合部３９間の屈曲部から所定距離離間しているとともに、この屈曲部間の中央に位置していることが好ましい。 The welded portion 40 has a predetermined distance from the bent portion between the inclined portion 34 and the engaging portion 35 in the first plate-like member 30 and the bent portion between the inclined portion 38 and the engaging portion 39 in the second plate-like member 31. It is preferable that they are spaced apart and located at the center between the bent portions.

第１の板状部材３０における取付部３３の軸方向の外側端部は、すなわち、試験片３２の一端部３２ａは、上記実施例１と同様に、拘束部１０により取外し可能に固定されている。また、第２の板状部材３１における取付部３７の軸方向の外側端部は、すなわち、試験片３２の他端部３２ｂは、上記実施例１と同様に、把持部１１に取外し可能に固定されている。 The outer end of the first plate-shaped member 30 in the axial direction of the mounting portion 33, that is, the one end portion 32a of the test piece 32 is detachably fixed by the restraining portion 10 as in the first embodiment. . Further, the outer end portion in the axial direction of the mounting portion 37 in the second plate-shaped member 31, that is, the other end portion 32 b of the test piece 32 is fixed to the grip portion 11 so as to be removable, similarly to the first embodiment. Has been.

また、試験片３２の凸部側（図８の上側）には、図８に示すように、上記実施例１と同様に、加熱部１５が、溶接部４０の上方に１カ所、その両側部で両傾斜部３４，３８の上方に夫々１カ所、その両側部における取付部３３，３７の上方に夫々１カ所の計５か所に配置されている。 Further, as shown in FIG. 8, the heating portion 15 is provided at one location above the welded portion 40 on the convex portion side (the upper side in FIG. 8) of the test piece 32, as shown in FIG. Thus, one is disposed above both inclined portions 34 and 38, and one is disposed above each of the attachment portions 33 and 37 on both sides thereof, for a total of five locations.

本実施例２においても、上記実施例１と同様の熱疲労試験装置１を用いて、上記実施例１と同様の熱疲労試験方法を行い、図７に示すような熱疲労特性を得る。 Also in the second embodiment, the same thermal fatigue testing apparatus 1 as that of the first embodiment is used, and the same thermal fatigue test method as that of the first embodiment is performed to obtain the thermal fatigue characteristics as shown in FIG.

上記試験片３２を用いて、上記実施例１と同様に、熱疲労試験を行うと、溶接部４０と係合部３５，３９との境界付近に最終的に亀裂が生じる。すなわち、溶接部４０を含む溶接部分がひずみが集中する頂部を構成する。 When the thermal fatigue test is performed using the test piece 32 in the same manner as in the first embodiment, a crack is finally generated near the boundary between the welded portion 40 and the engaging portions 35 and 39. That is, the welded portion including the welded portion 40 constitutes the top where strain is concentrated.

また、熱疲労特性を得る際に、試験片３２の山の高さ（取付部３３，３７の上面の高さと、係合部３５，３９の上面の高さの差）や、取付部３３，３７に対する傾斜部３４，３８の傾斜角度などを変化させることにより、異なる熱歪み量とすることができる。 Further, when obtaining the thermal fatigue characteristics, the height of the crest of the test piece 32 (the difference between the height of the upper surface of the mounting portions 33 and 37 and the height of the upper surface of the engaging portions 35 and 39), the mounting portion 33, By changing the inclination angle of the inclined portions 34 and 38 with respect to 37, the amount of thermal strain can be made different.

それ以外の構造は、前記実施例１と同様であるのでその説明を省略する。 Since the other structure is the same as that of the first embodiment, the description thereof is omitted.

本実施例２においても前記実施例１と同様の効果を奏する。 Also in the second embodiment, the same effects as in the first embodiment are obtained.

また、薄板を溶接して形成されるエキゾーストマニホールド等の自動車用部品では、溶接部に亀裂が生じることがあり、このような溶接部における熱疲労特性を上記のように得ることができ、部品に要求される使用サイクル等に応じて、部品に最適な金属材料を選定することができる。 In addition, in automotive parts such as exhaust manifolds formed by welding thin plates, cracks may occur in the welded parts, and thermal fatigue characteristics in such welded parts can be obtained as described above. An optimal metal material for a part can be selected according to a required use cycle.

［実施例３］
上記実施例２においては、第２の板状部材３１の内側端部と、第１の板状部材３０の係合部３５の平面部を、その短手方向（幅方向）全体に亘って隅肉溶接した溶接部４０により接合して試験片３２としたが、長尺で薄板状からなる複数の金属製の部材を任意の溶接により接合して試験片としてもよい。 [Example 3]
In the second embodiment, the inner end portion of the second plate-like member 31 and the flat portion of the engaging portion 35 of the first plate-like member 30 are cornered over the entire short direction (width direction). Although the test piece 32 is joined by the welded portion 40 that is meat welded, a plurality of long and thin metal members may be joined by arbitrary welding to form a test piece.

例えば、図９に示すように、第１の板状部材３０の内側端部と、第２の板状部材３１の内側端部同士を突き合わせ、その幅方向全体に亘って、突き合わせ溶接した溶接部４１により接合して試験片４２としてもよい。 For example, as shown in FIG. 9, the inner end of the first plate-like member 30 and the inner end of the second plate-like member 31 are butted together and butt welded over the entire width direction. The test piece 42 may be joined by 41.

また、図１０に示すように、第１の板状部材３０の内側端部と、第２の板状部材３１の内側端部同士を突き合わせるとともに、薄板状の第３の板状部材４３を、板状部材３０，３１の凹部側（図１０の下側）で、かつ、係合部３５，３９の内側端部に重ね合せて、３枚の板状部材３０，３１，４３を、その幅方向全体に亘って、三枚溶接した溶接部４４により接合して試験片４５としてもよい。 Further, as shown in FIG. 10, the inner end of the first plate-like member 30 and the inner end of the second plate-like member 31 are abutted with each other, and a thin plate-like third plate-like member 43 is provided. The three plate-like members 30, 31, 43 are overlapped on the concave side of the plate-like members 30, 31 (the lower side in FIG. 10) and on the inner ends of the engaging portions 35, 39. It is good also as a test piece 45 by joining with the welding part 44 which welded 3 sheets over the whole width direction.

また、図１１に示すように、第１の板状部材３０Ａにおける係合部３５の内側端部にさらに凸部側（図１１の上側）に湾曲する湾曲部３５Ａを設け、第２の板状部材３１Ａにおける係合部３９の内側端部にさらに凸部側（図１１の上側）に湾曲する湾曲部３９Ａを設け、この湾曲部３５Ａ，３９Ａ同士を突き合わせて、その幅方向全体に亘って、その曲げ側（図１１の下側）をフレア溶接した溶接部４８により接合して試験片４９としてもよい。 In addition, as shown in FIG. 11, a curved portion 35A that curves further to the convex portion side (upper side in FIG. 11) is provided at the inner end of the engaging portion 35 in the first plate-like member 30A, and the second plate-like member is provided. A curved portion 39A that curves further to the convex portion side (upper side in FIG. 11) is provided at the inner end of the engaging portion 39 in the member 31A, the curved portions 35A and 39A are butted together, and over the entire width direction, The bending side (the lower side in FIG. 11) may be joined by a welded portion 48 that is flare welded to form a test piece 49.

また、図１２に示すように、第１の板状部材３０Ａの湾曲部３５Ａと第２の板状部材３１Ａの湾曲部３９Ａ同士を突き合わせて、その先端側（図１２の上側）を、その幅方向全体に亘って、へり溶接した溶接部５０により接合して試験片５１としてもよい。 Also, as shown in FIG. 12, the curved portion 35A of the first plate-like member 30A and the curved portions 39A of the second plate-like member 31A are brought into contact with each other, and the distal end side (the upper side in FIG. 12) is set to its width. It is good also as the test piece 51 by joining by the welding part 50 which carried out edge welding over the whole direction.

また、図１３に示すように、第１の板状部材３０Ａの湾曲部３５Ａと第２の板状部材３１Ａの湾曲部３９Ａを、薄板状の第３の板状部材５３を間に挟んで重ね合せ、その幅方向全体に亘って、３枚へり溶接した溶接部５４により接合して試験片５５としてもよい。 Further, as shown in FIG. 13, the curved portion 35A of the first plate-like member 30A and the curved portion 39A of the second plate-like member 31A are overlapped with a thin plate-like third plate-like member 53 interposed therebetween. In addition, a test piece 55 may be formed by joining three welded portions 54 that are welded over the entire width direction.

また、溶接部の数は、上記のように１か所以外に、複数設けて試験片としてもよい。例えば、図１４に示すように、第１の板状部材３０の内側端部と、第２の板状部材３１の内側端部を相互に離間して設け、第３の板状部材４３を、板状部材３０，３１の凹部側（図１４の下側）で、かつ、第１の板状部材３０における係合部３５の内側端部と、第２の板状部材３１における係合部３９の内側端部にまたがって配設し、３枚の板状部材３０，３１，４３を、２か所において、その幅方向全体に亘って溶接した溶接部５７，５７により接合して試験片５８としてもよい。 Further, the number of welded portions may be a plurality of test pieces provided in addition to one place as described above. For example, as shown in FIG. 14, the inner end of the first plate member 30 and the inner end of the second plate member 31 are provided apart from each other, and the third plate member 43 is On the concave side (the lower side in FIG. 14) of the plate-like members 30, 31, the inner end of the engagement portion 35 in the first plate-like member 30, and the engagement portion 39 in the second plate-like member 31. The test piece 58 is formed by joining the three plate-like members 30, 31, 43 by welding portions 57, 57 welded over the entire width direction at two locations. It is good.

それ以外の構造は、前記実施例１，２と同様であるのでその説明を省略する。 Since other structures are the same as those of the first and second embodiments, description thereof is omitted.

本実施例３においても前記実施例１，２と同様の効果を奏する。 In the third embodiment, the same effects as in the first and second embodiments are obtained.

［実施例４］
上記実施例１〜３においては、加熱部１５を５個用いたが、加熱部１５は、試験片２の頂部３又は試験片３２，４２，４５，４９，５１，５５，５８の溶接部４０，４１，４４，４８，５０，５４，５７を所定加熱温度まで加熱することができれば、頂部３又は溶接部４０，４１，４４，４８，５０，５４，５７の上方に少なくとも１つ設けて構成してもよい。 [Example 4]
In the first to third embodiments, five heating parts 15 are used, but the heating part 15 is the top part 3 of the test piece 2 or the welded part 40 of the test pieces 32, 42, 45, 49, 51, 55, 58. , 41, 44, 48, 50, 54, 57 can be configured to be provided at least one above the top 3 or the welds 40, 41, 44, 48, 50, 54, 57 if they can be heated to a predetermined heating temperature. May be.

例えば、図１５，図１６に示すように、頂部３の上方と、傾斜部４，４の上方の計３カ所に加熱部１５を設けてよい。 For example, as shown in FIGS. 15 and 16, heating units 15 may be provided at a total of three locations above the top portion 3 and above the inclined portions 4 and 4.

それ以外の構造は、前記実施例１〜３と同様であるのでその説明を省略する。 Since other structures are the same as those in the first to third embodiments, description thereof is omitted.

本実施例４においても前記実施例１〜３と同様の効果を奏する。 In the fourth embodiment, the same effects as in the first to third embodiments are obtained.

［実施例５］
上記実施例１〜４においては、平板状の加熱部１５を用いたが、図１７，図１８に示すように、加熱部１５を、上記実施例１〜４と比較して、試験片２，３２，４２，４５，４９，５１，５５，５８の軸方向に長くなるように形成するとともに、軸方向に屈曲させて試験片２，３２，４２，４５，４９，５１，５５，５８の形状に対応した形状に形成するようにしてもよい。 [Example 5]
In the said Examples 1-4, although the flat heating part 15 was used, as shown in FIG.17, FIG.18, the heating part 15 is compared with the said Examples 1-4, the test piece 2, 32, 42, 45, 49, 51, 55, 58 are formed so as to be long in the axial direction and bent in the axial direction to form the test pieces 2, 32, 42, 45, 49, 51, 55, 58. You may make it form in the shape corresponding to.

それ以外の構造は、前記実施例１〜４と同様であるのでその説明を省略する。 Since other structures are the same as those in the first to fourth embodiments, description thereof is omitted.

本実施例５においても前記実施例１〜４と同様の効果を奏する。 Also in the fifth embodiment, the same effects as in the first to fourth embodiments are obtained.

［実施例６］
本実施例６は、図１９〜図２１に示すように、上記実施例１〜３の試験片２，３２，４２，４５，４９，５１，５５，５８及び少なくとも加熱部１５の発熱部１５ａを、遮蔽部材２０で覆った実施例である。 [Example 6]
In Example 6, as shown in FIGS. 19 to 21, the test pieces 2, 32, 42, 45, 49, 51, 55, 58 of Examples 1 to 3 and at least the heat generating part 15 a of the heating part 15 are provided. This is an embodiment covered with the shielding member 20.

遮蔽部材２０と試験片２，３２，４２，４５，４９，５１，５５，５８の間には、試験片２，３２，４２，４５，４９，５１，５５，５８の温度変化により形状変化した場合に遮蔽部材２０と試験片２，３２，４２，４５，４９，５１，５５，５８とが接触しないように隙間２１が形成されていれば、遮蔽部材２０の形状は任意に設定することができる。 Between the shielding member 20 and the test pieces 2, 32, 42, 45, 49, 51, 55, 58, the shape changed due to the temperature change of the test pieces 2, 32, 42, 45, 49, 51, 55, 58. In this case, if the gap 21 is formed so that the shielding member 20 and the test pieces 2, 32, 42, 45, 49, 51, 55, 58 are not in contact with each other, the shape of the shielding member 20 can be arbitrarily set. it can.

また、図２２に示すように、遮蔽部材２０の下部に上下方向に貫通する挿入穴２２を形成し、挿入穴２２に冷却部を構成する送風管２３を挿通するようにしてもよい。送風管２３は、頂部３又は溶接部４０，４１，４４，４８，５０，５４，５７の方向に指向して設けられている。 In addition, as shown in FIG. 22, an insertion hole 22 penetrating in the vertical direction may be formed in the lower part of the shielding member 20, and a blower pipe 23 constituting a cooling unit may be inserted into the insertion hole 22. The air duct 23 is provided in the direction of the top 3 or the welded portions 40, 41, 44, 48, 50, 54, 57.

それ以外の構造は、前記実施例１〜５と同様であるのでその説明を省略する。 Since other structures are the same as those in the first to fifth embodiments, description thereof is omitted.

本実施例６においても前記実施例１〜５と同様の効果を奏する。 In Example 6, the same effects as in Examples 1 to 5 are obtained.

本実施例６においては、更に、遮蔽部材２０により試験片２，３２，４２，４５，４９，５１，５５，５８を覆ったことにより、試験片２の頂部３又は試験片３２，４２，４５，４９，５１，５５，５８の溶接部４０，４１，４４，４８，５０，５４，５７を所定加熱温度に加熱する時間を短縮でき、熱疲労試験の時間を短縮できる。 In the sixth embodiment, the test piece 2, 32, 42, 45, 49, 51, 55, 58 is further covered with the shielding member 20, so that the top 3 of the test piece 2 or the test pieces 32, 42, 45 is covered. , 49, 51, 55, 58, the time for heating the welded portions 40, 41, 44, 48, 50, 54, 57 to a predetermined heating temperature can be shortened, and the time for the thermal fatigue test can be shortened.

また、冷却部を設けた場合には、冷却時間を短縮でき、熱疲労試験の時間を、より短縮できる。 Further, when the cooling unit is provided, the cooling time can be shortened, and the time for the thermal fatigue test can be further shortened.

［実施例７］
上記実施例１〜６においては、加熱部１５を試験片２，３２，４２，４５，４９，５１，５５，５８の凸部側に設けたが、図２３に示すように、試験片２，３２，４２，４５，４９，５１，５５，５８の凹部側に加熱部１５を設け、送風管２３は、試験片２，３２，４２，４５，４９，５１，５５，５８の凸部側に設けてもよい。 [Example 7]
In the said Examples 1-6, although the heating part 15 was provided in the convex part side of the test pieces 2, 32, 42, 45, 49, 51, 55, 58, as shown in FIG. 32, 42, 45, 49, 51, 55, 58 is provided with the heating unit 15 on the concave side, and the air duct 23 is provided on the convex side of the test pieces 2, 32, 42, 45, 49, 51, 55, 58. It may be provided.

それ以外の構造は、前記実施例１〜６と同様であるのでその説明を省略する。 Since other structures are the same as those in the first to sixth embodiments, description thereof is omitted.

本実施例７においても前記実施例１〜６と同様の効果を奏する。 In Example 7, the same effects as in Examples 1 to 6 are obtained.

［実施例８］
上記実施例１〜７においては、試験片２，３２，４２，４５，４９，５１，５５，５８に対して、加熱部１５の反対側に冷却部（送風管２３）を設けたが、冷却部は、試験片２の頂部３又は試験片３２，４２，４５，４９，５１，５５，５８の溶接部４０，４１，４４，４８，５０，５４，５７を指向して送風することができれば、任意の場所に設けることができ、例えば、図２４に示すように、加熱部１５と送風管２３を共に、凸部側又は凹部側に設けてもよいし、試験片２，３２に直交する図の表側又は裏側に配置してもよい。 [Example 8]
In the said Examples 1-7, although the cooling part (air blower tube 23) was provided in the other side of the heating part 15 with respect to the test pieces 2,32,42,45,49,51,55,58, If the part can be blown toward the top 3 of the test piece 2 or the welded parts 40, 41, 44, 48, 50, 54, 57 of the test pieces 32, 42, 45, 49, 51, 55, 58, For example, as shown in FIG. 24, both the heating unit 15 and the air duct 23 may be provided on the convex side or the concave side, or orthogonal to the test pieces 2 and 32. You may arrange | position to the front side or back side of a figure.

それ以外の構造は、前記実施例１〜７と同様であるのでその説明を省略する。 Since other structures are the same as those in the first to seventh embodiments, description thereof is omitted.

本実施例８においても前記実施例１〜７と同様の効果を奏する。 In the eighth embodiment, the same effects as in the first to seventh embodiments are obtained.

１熱疲労試験装置
２，３２，４２，４５，４９，５１，５５，５８試験片
３頂部
５ａ，３２ａ一端部
５ｂ，３２ｂ他端部
１０拘束部
１１把持部
１２規制部
１３荷重測定部
１５加熱部
２０遮蔽部材
４０，４１，４４，４８，５０，５４，５７溶接部 DESCRIPTION OF SYMBOLS 1 Thermal fatigue testing apparatus 2,32,42,45,49,51,55,58 Test piece 3 Top part 5a, 32a One end part 5b, 32b Other end part 10 Restraint part
DESCRIPTION OF SYMBOLS 11 Gripping part 12 Control part 13 Load measuring part 15 Heating part 20 Shielding member 40, 41, 44, 48, 50, 54, 57 Welding part

Claims

A thermal fatigue test apparatus for measuring thermal fatigue characteristics of a test piece composed of one or more plate-shaped metal members,
The test piece has a top where strain is concentrated when measuring thermal fatigue properties,
A restraining portion for restraining one end portion of the test piece, a gripping portion for gripping the other end portion of the test piece, and a load measuring portion interlocking with the gripping portion,
The load measuring unit measures a load generated by expansion and contraction of the test piece due to temperature change,
A thermal fatigue testing apparatus comprising at least one or more planar heating sections, wherein one heating section is provided at a central portion in the axial direction of the test piece so as to be separated from the top.

The thermal fatigue testing apparatus according to claim 1, wherein the top portion is formed at a central portion of the flat plate by bending a single flat plate made of metal in the thickness direction of the test piece.

The thermal fatigue test according to claim 1, wherein the test piece is composed of a plurality of plate-shaped metal members, the members are joined to each other by welding, and the welded portion is used as the top portion. apparatus.

It has at least three or more planar heating parts, and the heating parts are provided on both sides of the top in the axial direction of the test piece so as to be separated from the test piece, respectively. The thermal fatigue test apparatus according to claim 1, 2 or 3.

The thermal fatigue testing apparatus according to any one of claims 1 to 4, wherein the grip portion can be moved only in an axial direction of the test piece by a restricting portion.

The thermal fatigue test apparatus according to claim 1, wherein at least a part of the test piece and the heating unit is covered with a shielding member.

The thermal fatigue testing apparatus according to claim 1, further comprising a cooling unit directed to the top.

Measure the thermal fatigue characteristics of a test piece composed of one or more plate-shaped metal members,
The test piece has a top where strain is concentrated when measuring thermal fatigue properties,
A restraining portion for restraining one end portion of the test piece, a gripping portion for gripping the other end portion of the test piece, and a load measuring portion interlocking with the gripping portion,
The load measuring unit measures a load generated by expansion and contraction of the test piece due to temperature change,
Using a thermal fatigue testing apparatus having at least one or more planar heating parts, the one heating part being provided in the axially central part of the test piece so as to be separated from the top part,
The test piece is repeatedly heated to a predetermined heating temperature and cooled to a predetermined cooling temperature, and one heating and one cooling are defined as one cycle, and the maximum value of the load in this cycle is one thermal fatigue. Thermal fatigue test, characterized in that the number of cycles when the ratio falls below a predetermined ratio for the first time with respect to the maximum load value in the entire test is the endurance limit of the test piece at the predetermined heating temperature when the test is performed Method.

The thermal fatigue test method is performed a plurality of times to obtain a relational expression between the endurance limit of the test piece at the predetermined heating temperature when the test is performed and the amount of thermal strain when the endurance limit is measured. The thermal fatigue test method according to claim 8.

The thermal fatigue test method according to claim 9, wherein the relational expression is obtained at different predetermined heating temperatures.