JP2022054960A - Half bearing for crank shaft of internal combustion engine - Google Patents

Abstract

To provide a half bearing for a crank shaft of an internal combustion engine excellent in embedding performance of foreign matters mixed therein together with an oil.SOLUTION: A depth of circumferential grooves 6 is constituted to be minimum at circumferential central portions of inner peripheral surfaces 5 of half bearings 2, 3, and gradually increased toward circumferential end portions of the inner peripheral surfaces 5 of the half bearings 2, 3. Thus the depth of the circumferential grooves 6 is deep near the circumferential end portions of the inner peripheral surfaces 5 of the half bearings 2, 3, and allowance to embed foreign matters in the circumferential grooves 6 in which a soft bearing material 8 is housed, is increased. Accordingly, the foreign matters can be easily completely embedded in the soft bearing material 8 in the circumferential grooves 6, and hardly project to a radial inner side with respect to the inner peripheral surfaces 5, even when the foreign matters are locally embedded in a concentrated manner near the circumferential end portions in the circumferential grooves 6 in which the soft bearing material 8 is housed.SELECTED DRAWING: Figure 1

Description

本発明は、鋼裏金層と軸受合金層とを有し、且つ２個を組み合せて円筒形を構成する半割形状に形成された内燃機関のクランク軸用の半割軸受であって、半割軸受の内周面には、軸線方向に軸受合金層の軸受合金と交互に配置され、且つ円周方向の全周にわたって延在する複数の周方向溝を形成すると共に、その周方向溝に軟質軸受材料を収容して内周面が面一となるように形成された内燃機関のクランク軸用の半割軸受に関するものである。 The present invention is a half-split bearing for a crank shaft of an internal combustion engine, which has a steel back metal layer and a bearing alloy layer and is formed into a half-split shape forming a cylindrical shape by combining the two. On the inner peripheral surface of the bearing, a plurality of circumferential grooves are alternately arranged in the axial direction with the bearing alloy of the bearing alloy layer and extend over the entire circumference in the circumferential direction, and the circumferential grooves are soft. It relates to a half-split bearing for a crank shaft of an internal combustion engine formed so as to accommodate a bearing material so that the inner peripheral surface is flush with each other.

従来、内燃機関のクランク軸用すべり軸受は、一対の半割軸受を組み合わせて円筒形にしたものを使用している。また、クランク軸のジャーナル部用の一対の半割軸受のうち少なくとも一方の半割軸受の内周面には、半割軸受の周方向に延在する油溝が形成されている（例えば、特許文献１）。 Conventionally, as a slide bearing for a crank shaft of an internal combustion engine, a pair of half-split bearings are combined to form a cylindrical shape. Further, an oil groove extending in the circumferential direction of the half-split bearing is formed on the inner peripheral surface of at least one half-split bearing of the pair of half-split bearings for the journal portion of the crank shaft (for example, a patent). Document 1).

上記した内燃機関のクランク軸用すべり軸受への油の供給は、まず、クランク軸のジャーナル部用すべり軸受の外部から上半割軸受に形成される供給穴を介して内周面に形成された油溝内に供給され、その油がクランク軸のジャーナル部用すべり軸受の内周面（摺動面）及びクランクピン用すべり軸受の内周面に供給される。このとき、内燃機関の最初の運転時には、上半割軸受の油溝に供給される油に対して油路内に残留した異物が混入する場合が多いことが知られている。そこで、このような内燃機関のクランク軸用すべり軸受においては、その内周面に混入した異物を軟質軸受材料に埋収させるための各種方法が提案されている。 The oil supply to the above-mentioned plain bearing for the crank shaft of the internal combustion engine was first formed on the inner peripheral surface from the outside of the plain bearing for the journal portion of the crank shaft through a supply hole formed in the upper half bearing. It is supplied into the oil groove, and the oil is supplied to the inner peripheral surface (sliding surface) of the slide bearing for the journal portion of the crank shaft and the inner peripheral surface of the slide bearing for the crank pin. At this time, it is known that during the first operation of the internal combustion engine, foreign matter remaining in the oil passage is often mixed with the oil supplied to the oil groove of the upper half-split bearing. Therefore, in such a slide bearing for a crank shaft of an internal combustion engine, various methods for embedding foreign matter mixed in the inner peripheral surface in a soft bearing material have been proposed.

例えば、特開昭５７－１４４３１３号公報（特許文献２）や特開２０１１－１３３００１号公報（特許文献３）には、鋼裏金と硬質の軸受合金とからなるすべり軸受であって、その内周面には、軸受の軸線方向に軸受合金と交互に配置され、且つ軸受の内周面のほぼ全体にわたって延びて軟質軸受材料を収容する複数の溝状凹部を形成したものが開示されている。これによれば、Ａｌ系合金やＣｕ系合金などの硬質な軸受合金が相手軸からの負荷を支え、ホワイトメタルやプラスチック等の軟質軸受材料にすべり軸受の内周面に混入する異物を埋収させることにより、硬質な軸受合金が異物によってダメージを受けることを防いでいる。 For example, Japanese Patent Application Laid-Open No. 57-144313 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2011-133001 (Patent Document 3) describe a slide bearing made of a steel backing metal and a hard bearing alloy, and the inner circumference thereof. On the surface, a plurality of groove-shaped recesses are disclosed which are alternately arranged with the bearing alloy in the axial direction of the bearing and extend over almost the entire inner peripheral surface of the bearing to accommodate the soft bearing material. According to this, hard bearing alloys such as Al-based alloys and Cu-based alloys support the load from the mating shaft, and soft bearing materials such as white metal and plastic embed foreign matter mixed in the inner peripheral surface of the slide bearing. This prevents the hard bearing alloy from being damaged by foreign matter.

また、実開平２－９３２６号公報（特許文献４）には、内周面に延在する周方向溝を形成したすべり軸受であって、該周方向溝は、油を供給する開口部から、軸の相対回転先側に向かって深さを徐々に浅くし、溝底に軟質軸受材料を形成したものが開示されており、油に混入する異物を埋収、除去している。 Further, in Japanese Patent Application Laid-Open No. 2-9326 (Patent Document 4), it is a slide bearing having a circumferential groove extending on the inner peripheral surface, and the circumferential groove is formed from an opening for supplying oil. It is disclosed that the depth is gradually reduced toward the relative rotation destination side of the shaft to form a soft bearing material at the bottom of the groove, and foreign matter mixed in the oil is buried and removed.

特開平８－２７７８３１号公報Japanese Unexamined Patent Publication No. 8-277831 特開昭５７－１４４３１３号公報Japanese Unexamined Patent Publication No. 57-144313 特開２０１１－１３３００１号公報Japanese Unexamined Patent Publication No. 2011-133001 実開平２－９３２６号公報Jikkenhei 2-9326 Gazette

ところで、内燃機関のクランク軸用すべり軸受の内周面に混入した異物は、クランク軸の回転による油の流れに付随し、油溝内をクランク軸の相対回転先側へと流れるが、半割軸受の組合せ面付近に到達すると、油溝を形成しない下半割軸受の周方向端面が障壁となって油とともに内周面側に浮上する。このため、異物は、クランク軸の相対回転方向の前方側の油溝の周方向端部付近のすべり軸受の内周面、特に上半割軸受の油溝の周方向端部付近の内周面および油溝の先側の下半割軸受の周方向端面付近の内周面に混入しやすい。すなわち、特許文献２や特許文献３では、上半割軸受の油溝の周方向端部付近の内周面および油溝の先側の下半割軸受の周方向端面付近の内周面のうち、硬質な軸受合金には異物が埋収されず、軟質軸受材料を収容した溝状凹部に異物が集中して埋収されるようになる。また、この異物は、クランク軸の表面により軟質軸受材料に押し込まれるが、局部的に多くの異物が埋収した埋収部が形成されると、異物の一部は軟質軸受材料に完全に埋没するのでなく、すべり軸受の内周面（軟質軸受材料の表面）から突出してしまい、クランク軸の表面と接触しやすい状態にある。このため、すべり軸受の内周面側における局部的に多くの異物が埋収した埋収部では、クランク軸の表面との接触による発熱が大きい。そして、軟質軸受材料の軟化、溶融が起きて許容限界に達すると、埋収部に埋収していた多数の異物が同時にすべり軸受の内周面へ送られるので、すべり軸受の焼付が起きやすい。 By the way, foreign matter mixed in the inner peripheral surface of the slide bearing for the crank shaft of the internal combustion engine accompanies the flow of oil due to the rotation of the crank shaft, and flows in the oil groove to the relative rotation destination side of the crank shaft, but half of it. When it reaches the vicinity of the combination surface of the bearing, the peripheral end surface of the lower half-split bearing that does not form an oil groove acts as a barrier and floats to the inner peripheral surface side together with the oil. Therefore, foreign matter is removed from the inner peripheral surface of the slide bearing near the circumferential end of the oil groove on the front side in the relative rotation direction of the crank shaft, especially the inner peripheral surface of the oil groove of the upper half-split bearing near the circumferential end. And it is easy to mix in the inner peripheral surface near the circumferential end surface of the lower half bearing on the tip side of the oil groove. That is, in Patent Document 2 and Patent Document 3, of the inner peripheral surface near the circumferential end of the oil groove of the upper half-split bearing and the inner peripheral surface near the circumferential end of the lower half-split bearing on the tip side of the oil groove. Foreign matter is not embedded in the hard bearing alloy, and foreign matter is concentrated and embedded in the groove-shaped recesses containing the soft bearing material. Further, this foreign matter is pushed into the soft bearing material by the surface of the crank shaft, but when a buried portion in which a large amount of foreign matter is locally buried is formed, a part of the foreign matter is completely buried in the soft bearing material. Instead, it protrudes from the inner peripheral surface of the slide bearing (the surface of the soft bearing material) and is in a state where it easily comes into contact with the surface of the crank shaft. For this reason, in the buried portion where a large amount of foreign matter is locally buried on the inner peripheral surface side of the slide bearing, heat generation due to contact with the surface of the crank shaft is large. When the soft bearing material softens and melts and reaches the permissible limit, a large number of foreign substances buried in the buried portion are simultaneously sent to the inner peripheral surface of the plain bearing, so that seizure of the plain bearing is likely to occur. ..

また、特許文献４では、クランク軸の相対回転先側の周方向溝の深さが浅い部分の軟質軸受材料に、異物が集中して埋収されやすい。この場合にも、局部的に多くの異物が埋収した埋収部において、特許文献２や特許文献３と同じく異物が軟質軸受材料の表面から突出してしまい、クランク軸の表面との接触による発熱で軟質軸受材料の軟化、溶融が起きて許容限界に達すると、埋収部に埋収していた多数の異物が同時にすべり軸受の内周面へ送られるので、すべり軸受の焼付が起きやすい。 Further, in Patent Document 4, foreign matter is likely to be concentrated and buried in the soft bearing material in the portion where the depth of the circumferential groove on the relative rotation destination side of the crank shaft is shallow. In this case as well, in the buried portion where a large amount of foreign matter is locally buried, the foreign matter protrudes from the surface of the soft bearing material as in Patent Document 2 and Patent Document 3, and heat is generated due to contact with the surface of the crank shaft. When the soft bearing material softens and melts and reaches the allowable limit, a large number of foreign substances buried in the buried portion are simultaneously sent to the inner peripheral surface of the plain bearing, so that seizure of the plain bearing is likely to occur.

本発明は、上記した事情に鑑みなされたものであり、その目的とするところは、油に付随し混入する異物の埋収性に優れた内燃機関のクランク軸用の半割軸受を提供することにある。 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a half-split bearing for a crank shaft of an internal combustion engine having excellent burial property of foreign matter mixed with oil. It is in.

上記した目的を達成するために、請求項１に係る発明においては、鋼裏金層と軸受合金層とを有し、且つ２個を組み合せて円筒形を構成する半割形状に形成された内燃機関のクランク軸用の半割軸受であって、前記半割軸受の内周面には、軸線方向に前記軸受合金層の軸受合金と交互に配置され、且つ円周方向の全周にわたって延在する複数の周方向溝を形成すると共に、該周方向溝に軟質軸受材料を収容して内周面が面一となるように形成された内燃機関のクランク軸用の半割軸受において、前記周方向溝の深さは、前記半割軸受の内周面の周方向中央部において最小となり、前記半割軸受の内周面の周方向両端部に向かって次第に深く形成されていることを特徴とする。 In order to achieve the above object, in the invention according to claim 1, an internal combustion engine having a steel back metal layer and a bearing alloy layer and formed into a half-split shape forming a cylindrical shape by combining the two. This is a half-split bearing for a crank shaft, and is arranged alternately with the bearing alloy of the bearing alloy layer in the axial direction on the inner peripheral surface of the half-split bearing, and extends over the entire circumference in the circumferential direction. In a half-split bearing for a crank shaft of an internal combustion engine, which is formed so that a plurality of circumferential grooves are formed and a soft bearing material is accommodated in the circumferential grooves so that the inner peripheral surfaces are flush with each other, the circumferential direction is formed. The depth of the groove is the minimum at the central portion in the circumferential direction of the inner peripheral surface of the half-split bearing, and is characterized in that it is gradually formed deeper toward both ends in the circumferential direction of the inner peripheral surface of the half-split bearing. ..

請求項２に係る発明においては、請求項１記載の内燃機関のクランク軸用の半割軸受において、前記周方向溝の幅は、前記半割軸受の内周面の周方向中央部において最小となり、前記半割軸受の内周面の周方向両端部に向かって次第に広く形成されていることを特徴とする。 In the invention according to claim 2, in the half-split bearing for the crank shaft of the internal combustion engine according to claim 1, the width of the circumferential groove is the minimum in the circumferential center portion of the inner peripheral surface of the half-split bearing. The half-split bearing is characterized in that it is gradually formed wider toward both ends in the circumferential direction of the inner peripheral surface of the bearing.

請求項３に係る発明においては、請求項１又は請求項２記載の内燃機関のクランク軸用の半割軸受において、前記半割軸受の内周面の周方向両端部には、クラッシュリリーフが形成されていることを特徴とする。 In the invention according to claim 3, in the half-split bearing for the crank shaft of the internal combustion engine according to claim 1 or 2, crash relief is formed at both ends in the circumferential direction of the inner peripheral surface of the half-split bearing. It is characterized by being done.

本発明において、半割軸受の内周面には、軸線方向に軸受合金層の軸受合金と交互に配置され、且つ円周方向の全周にわたって延在する複数の周方向溝を形成すると共に、該周方向溝に軟質軸受材料を収容して内周面が面一となるように形成され、周方向溝の深さが、半割軸受の内周面の周方向中央部において最小となり、半割軸受の内周面の周方向両端部に向かって次第に深く形成されている。このような構成では、半割軸受の内周面の周方向端部付近において、周方向溝の深さが深くなっており、軟質軸受材料を収容した周方向溝に異物を埋収することが可能な許容量が大きくなっている。このため、軟質軸受材料を収容した周方向溝において周方向端部付近に局部的に異物が集中した埋収があっても、その異物は、周方向溝内の軟質軸受材料に完全に埋収され易く、内周面よりも径方向の内側に突出し難くすることができる。したがって、半割軸受は、異物による内周面の焼付等の損傷を防ぐことができる。 In the present invention, on the inner peripheral surface of the half-split bearing, a plurality of circumferential grooves are alternately arranged in the axial direction with the bearing alloy of the bearing alloy layer and extend over the entire circumference in the circumferential direction. The flexible bearing material is accommodated in the circumferential groove and formed so that the inner peripheral surface is flush with each other, and the depth of the circumferential groove is minimized at the central portion of the inner peripheral surface of the half-split bearing in the circumferential direction. It is gradually formed deeper toward both ends in the circumferential direction of the inner peripheral surface of the split bearing. In such a configuration, the depth of the circumferential groove is deep near the circumferential end of the inner peripheral surface of the half-split bearing, and foreign matter can be embedded in the circumferential groove containing the soft bearing material. The possible allowance is increasing. Therefore, even if foreign matter is locally concentrated and buried near the peripheral end in the circumferential groove containing the soft bearing material, the foreign matter is completely buried in the soft bearing material in the circumferential groove. It is easy to make the bearing, and it is possible to make it difficult to project inward in the radial direction from the inner peripheral surface. Therefore, the half-split bearing can prevent damage such as seizure of the inner peripheral surface due to foreign matter.

本発明の実施例１におけるクランク軸を支持する上半割軸受と下半割軸受からなるすべり軸受の正面図（Ａ）と、上半割軸受と下半割軸受の内周面側から見た平面図（Ｂ）である。The front view (A) of the slide bearing composed of the upper half-split bearing and the lower half-split bearing supporting the crank shaft in the first embodiment of the present invention, and the inner peripheral surface side of the upper half-split bearing and the lower half-split bearing. It is a plan view (B). 図１に示す半割軸受の正面図である。It is a front view of the half-split bearing shown in FIG. 図１に示す半割軸受の断面図である。It is sectional drawing of the half-split bearing shown in FIG. 本発明の実施例２における下半割軸受の内周面側から見た平面図である。It is a top view seen from the inner peripheral surface side of the lower half split bearing in Example 2 of this invention. 本発明の実施例３におけるクランク軸を支持する上半割軸受と下半割軸受からなるすべり軸受の正面図（Ａ）と、上半割軸受と下半割軸受の内周面側から見た平面図（Ｂ）である。A front view (A) of a slide bearing composed of an upper half-split bearing and a lower half-split bearing supporting a crank shaft in Example 3 of the present invention, and a view from the inner peripheral surface side of the upper half-split bearing and the lower half-split bearing. It is a plan view (B).

以下、本発明の実施形態について図１乃至図３を参照して説明する。図１は、クランク軸２０を支持する２つの上半割軸受２と下半割軸受３からなるすべり軸受１の正面図（Ａ）と、上半割軸受２と下半割軸受３の内周面５側から見た平面図（Ｂ）であり、図２は、半割軸受２，３の内周面５と周方向溝６の底面との関係を示す半割軸受２，３の正面図であり、図３は、半割軸受２，３の内周面５の構造を示す断面図である。なお、上記した図は、実施形態に係るすべり軸受１の概略図であり、構成、構造等を理解し易くするために各箇所が誇張あるいは省略して描かれている。 Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 shows a front view (A) of a slide bearing 1 composed of two upper half-split bearings 2 and a lower half-split bearing 3 supporting a crank shaft 20, and an inner circumference of the upper half-split bearing 2 and the lower half-split bearing 3. It is a plan view (B) seen from the surface 5 side, and FIG. 2 is a front view of the half-split bearings 2 and 3 showing the relationship between the inner peripheral surface 5 of the half-split bearings 2 and 3 and the bottom surface of the circumferential groove 6. FIG. 3 is a cross-sectional view showing the structure of the inner peripheral surface 5 of the half-split bearings 2 and 3. The above-mentioned figure is a schematic view of the slide bearing 1 according to the embodiment, and each part is exaggerated or omitted in order to make it easier to understand the configuration, structure, and the like.

（実施例１の半割軸受の構成）
まず、請求項１に係る発明に対応する実施例１について、図１を参照して説明する。図１（Ａ）に示すように、実施例１のすべり軸受１は、半割形状に形成された半割軸受２，３を上下２個組み合わせることにより円筒形を構成し、内燃機関のクランク軸２０を回転可能に支持するものである。この半割軸受２，３の内周面５は、耐焼付性など半割軸受２，３の軸受特性を満足するために、例えば、鋼裏金層９に軸受合金層１０がライニングされている（図３参照）。すなわち、鋼裏金層９は、半割軸受２，３の外径側に配置され、軸受合金層１０は、半割軸受２，３の内径側に配置される。なお、軸受合金層１０は、Ａｌ合金やＣｕ合金等の公知の軸受合金を適用することができる。 (Structure of half-split bearing of Example 1)
First, Example 1 corresponding to the invention according to claim 1 will be described with reference to FIG. As shown in FIG. 1A, the slide bearing 1 of the first embodiment has a cylindrical shape by combining two upper and lower half-split bearings 2 and 3 formed in a half-split shape, and has a crank shaft of an internal combustion engine. It supports 20 rotatably. The inner peripheral surface 5 of the half-split bearings 2 and 3 is lined with a bearing alloy layer 10 on, for example, a steel back metal layer 9 in order to satisfy the bearing characteristics of the half-split bearings 2 and 3 such as seizure resistance. See Figure 3). That is, the steel back metal layer 9 is arranged on the outer diameter side of the half split bearings 2 and 3, and the bearing alloy layer 10 is arranged on the inner diameter side of the half split bearings 2 and 3. A known bearing alloy such as an Al alloy or a Cu alloy can be applied to the bearing alloy layer 10.

また、図１（Ｂ）に示すように、半割軸受２，３のうち上半割軸受２の内周面５には、半割軸受２，３と該半割軸受２，３に支持されるクランク軸２０との間に潤滑油を供給するための油溝４が、円周方向の全周にわたって軸線方向（幅方向）のほぼ中央に形成されている。また、油溝４のほぼ中央には、外部から油の供給を受けるための油穴４ａが、上半割軸受２の壁厚を径方向に貫通して形成されている。 Further, as shown in FIG. 1 (B), of the half-split bearings 2 and 3, the inner peripheral surface 5 of the upper half-split bearing 2 is supported by the half-split bearings 2 and 3 and the half-split bearings 2 and 3. An oil groove 4 for supplying lubricating oil to the crank shaft 20 is formed substantially in the center of the axial direction (width direction) over the entire circumference in the circumferential direction. Further, an oil hole 4a for receiving oil supply from the outside is formed substantially in the center of the oil groove 4 so as to penetrate the wall thickness of the upper half-split bearing 2 in the radial direction.

また、半割軸受２，３の内周面５には、矩形形状（図３参照）に形成された複数の周方向溝６が、軸線方向に軸受合金層１０の軸受合金と交互に配置されると共に、円周方向の全周にわたって延在するように形成されている。また、複数の周方向溝６には、軟質軸受材料８が収容（充填）されることにより内周面５が面一となるように形成されている。なお、軟質軸受材料８は、ＳｎまたはＳｎ合金、ＰｂまたはＰｂ合金、ＢｉまたはＢｉ合金、摺動用樹脂組成物等の公知の軟質軸受材料を適用することができる。 Further, on the inner peripheral surfaces 5 of the half-split bearings 2 and 3, a plurality of circumferential grooves 6 formed in a rectangular shape (see FIG. 3) are alternately arranged in the axial direction with the bearing alloy of the bearing alloy layer 10. At the same time, it is formed so as to extend over the entire circumference in the circumferential direction. Further, the plurality of circumferential grooves 6 are formed so that the inner peripheral surface 5 is flush with each other by accommodating (filling) the soft bearing material 8. As the soft bearing material 8, known soft bearing materials such as Sn or Sn alloys, Pb or Pb alloys, Bi or Bi alloys, and sliding resin compositions can be applied.

しかして、内燃機関のクランク軸２０のすべり軸受１への油の供給は、まず、すべり軸受１の外部から上半割軸受２に形成される油穴４ａを介して内周面５に形成された油溝４内に供給され、その油がすべり軸受１の内周面５に供給される。このとき、内燃機関の最初の運転時には、上半割軸受２の油溝４に供給される油に対して油路内に残留した異物が混入する場合が多い。この異物は、クランク軸２０の回転による油の流れに付随し、油溝４内をクランク軸２０の相対回転方向の前方側へ流れるが、半割軸受２，３の周方向端面７付近に到達すると、油溝４を形成しない下半割軸受３の周方向端面７が障壁となって油とともに内周面５側に浮上する。このため、異物は、クランク軸２０の相対回転方向先側の油溝４の端部付近のすべり軸受１の内周面５、特に上半割軸受２の周方向端面７付近（油溝４の端部付近）の内周面５および油溝４ａの先側の下半割軸受３の周方向端面７付近の内周面５に混入し、それらの内周面５に形成された軟質軸受材料８を収容した周方向溝６に集中して埋収されやすくなっている。 Then, the oil supply to the slide bearing 1 of the crank shaft 20 of the internal combustion engine is first formed on the inner peripheral surface 5 from the outside of the slide bearing 1 through the oil hole 4a formed in the upper half bearing 2. It is supplied into the oil groove 4, and the oil is supplied to the inner peripheral surface 5 of the slide bearing 1. At this time, at the time of the first operation of the internal combustion engine, foreign matter remaining in the oil passage is often mixed with the oil supplied to the oil groove 4 of the upper half-split bearing 2. This foreign matter accompanies the flow of oil due to the rotation of the crank shaft 20, and flows in the oil groove 4 toward the front side in the relative rotation direction of the crank shaft 20, but reaches the vicinity of the circumferential end faces 7 of the half-split bearings 2 and 3. Then, the peripheral end surface 7 of the lower half-split bearing 3 that does not form the oil groove 4 serves as a barrier and floats to the inner peripheral surface 5 side together with the oil. Therefore, the foreign matter is present on the inner peripheral surface 5 of the slide bearing 1 near the end of the oil groove 4 on the front side in the relative rotation direction of the crank shaft 20, particularly in the vicinity of the circumferential end surface 7 of the upper half split bearing 2 (in the oil groove 4). A soft bearing material that is mixed into the inner peripheral surface 5 (near the end) and the inner peripheral surface 5 near the circumferential end surface 7 of the lower half split bearing 3 on the front side of the oil groove 4a, and is formed on the inner peripheral surface 5. It is easy to concentrate and bury in the circumferential groove 6 accommodating the 8.

次に、本発明の要部を構成する周方向溝６について、図２を参照して説明する。図２に示すように、軟質軸受材料８を収容した周方向溝６の底面を形成する円弧の中心Ｏ’は、半割軸受２，３の垂直中心線上で、半割軸受２，３の中心位置Ｏに対して半割軸受２，３の内周面から遠い側に偏心させている。また、軟質軸受材料８を収容した周方向溝６の底面を形成する円弧の半径Ｒ２は、半割軸受２，３の内周面５を形成する円弧の半径Ｒ１よりも若干長くしている。このため、周方向溝６の深さＤは、半割軸受２，３の内周面５の周方向中央部Ｃにおいて最小となり、半割軸受２，３の内周面５の周方向端部Ｅ（周方向端面７）に向かって次第に深く形成されている。周方向溝６の深さＤは、内周面５から周方向溝６の底面までの半割軸受２，３の径方向の長さを意味する。なお、上記の周方向溝６の底面を形成する円弧および半割軸受２，３の内周面５を形成する円弧は、楕円弧であってもよい。 Next, the circumferential groove 6 constituting the main part of the present invention will be described with reference to FIG. As shown in FIG. 2, the center O'of the arc forming the bottom surface of the circumferential groove 6 accommodating the soft bearing material 8 is the center of the half-split bearings 2 and 3 on the vertical center line of the half-split bearings 2 and 3. It is eccentric to the side far from the inner peripheral surface of the half-split bearings 2 and 3 with respect to the position O. Further, the radius R2 of the arc forming the bottom surface of the circumferential groove 6 accommodating the soft bearing material 8 is slightly longer than the radius R1 of the arc forming the inner peripheral surfaces 5 of the half-split bearings 2 and 3. Therefore, the depth D of the circumferential groove 6 is the minimum at the circumferential central portion C of the inner peripheral surfaces 5 of the half-split bearings 2 and 3, and the circumferential end portion of the inner peripheral surfaces 5 of the half-split bearings 2 and 3. It is gradually formed deeper toward E (circumferential end face 7). The depth D of the circumferential groove 6 means the radial length of the half-split bearings 2 and 3 from the inner peripheral surface 5 to the bottom surface of the circumferential groove 6. The arc forming the bottom surface of the circumferential groove 6 and the arc forming the inner peripheral surfaces 5 of the half-split bearings 2 and 3 may be elliptical arcs.

上記したように、異物は、半割軸受２，３の周方向端面７付近の内周面５において、クランク軸２０の表面により周方向溝６内の軟質軸受材料８に押し込まれて局部的に集中して埋収されやすい。例えば、周方向溝６の深さＤを内周面５の周方向で一定とする場合、または、周方向溝６の深さＤを内周面５の周方向中央部Ｃにおいて最大で、周方向端部Ｅ側に向かって次第に浅くする場合には、半割軸受２，３の周方向端面７付近の周方向溝６内の軟質軸受材料８に局部的に異物が集中して埋収してしまうと、異物の一部は、軟質軸受材料８内に先に埋収された異物が抵抗となり、あるいは周方向溝６の底面の硬質な軸受合金が抵抗となり、軟質軸受材料８内に完全には押し込まれないで、内周面５（軟質軸受材料８の表面）よりも径方向の内側に突出してしまう。 As described above, the foreign matter is locally pushed into the soft bearing material 8 in the circumferential groove 6 by the surface of the crank shaft 20 on the inner peripheral surface 5 near the circumferential end surface 7 of the half-split bearings 2 and 3. It is easy to concentrate and be buried. For example, when the depth D of the circumferential groove 6 is constant in the circumferential direction of the inner peripheral surface 5, or the depth D of the circumferential groove 6 is the maximum in the circumferential central portion C of the inner peripheral surface 5, the circumference is the same. When gradually shallowing toward the direction end E side, foreign matter is locally concentrated and buried in the soft bearing material 8 in the circumferential groove 6 near the circumferential end faces 7 of the half-split bearings 2 and 3. Then, as for a part of the foreign matter, the foreign matter previously embedded in the soft bearing material 8 becomes a resistance, or the hard bearing alloy on the bottom surface of the circumferential groove 6 becomes a resistance, and the foreign matter is completely contained in the soft bearing material 8. It is not pushed into the inner peripheral surface 5 (the surface of the soft bearing material 8) and protrudes inward in the radial direction.

しかしながら、本発明では、周方向溝６の深さＤは、半割軸受２，３の内周面５の周方向中央部Ｃにおいて最小となり、半割軸受２，３の内周面５の周方向端部Ｅに向かって次第に深くなる構成としている。このため、半割軸受２，３の内周面５の周方向端部Ｅ付近では、周方向溝６の深さＤが深くなっており、軟質軸受材料８を収容した周方向溝６に異物を埋収することが可能な許容量が大きくなっている。したがって、軟質軸受材料８を収容した周方向溝６において周方向端部付近に局部的に異物が集中した埋収があっても、その異物は、周方向溝６内の軟質軸受材料８に完全に埋収され易く、内周面５（軟質軸受材料８の表面）よりも径方向の内側に突出し難くすることができる。 However, in the present invention, the depth D of the circumferential groove 6 is the minimum in the circumferential central portion C of the inner peripheral surfaces 5 of the half-split bearings 2 and 3, and the circumference of the inner peripheral surfaces 5 of the half-split bearings 2 and 3 is minimized. The structure gradually becomes deeper toward the direction end E. Therefore, in the vicinity of the circumferential end E of the inner peripheral surfaces 5 of the half-split bearings 2 and 3, the depth D of the circumferential groove 6 is deep, and foreign matter is formed in the circumferential groove 6 accommodating the soft bearing material 8. The allowable amount that can be buried is increasing. Therefore, even if foreign matter is locally concentrated and buried near the peripheral end portion in the circumferential groove 6 accommodating the soft bearing material 8, the foreign matter is completely contained in the soft bearing material 8 in the circumferential groove 6. It is easy to be buried in the inner peripheral surface 5 (the surface of the soft bearing material 8), and it is possible to make it less likely to protrude inward in the radial direction.

また、半割軸受２，３は、周方向溝６の深さＤが半割軸受２，３の内周面５の周方向中央部Ｃにおいて最小となっており、内周面５の周方向中央部Ｃに近いほど、軸受合金層１０における周方向溝６に収容される軟質軸受材料８の体積割合が小さくなっている。このため、内燃機関の運転時、クランク軸２０から半割軸受２，３の内周面５に加わる負荷は、半割軸受２，３の周方向中央部Ｃ付近で最大となっているが、その周方向中央部Ｃ付近では、主に負荷を支える軸受合金層１０における軸受合金の体積割合が大きくなるので、クランク軸２０からの負荷能力を高くすることができる。 Further, in the half-split bearings 2 and 3, the depth D of the circumferential groove 6 is the minimum in the circumferential central portion C of the inner peripheral surface 5 of the half-split bearings 2 and 3, and the circumferential direction of the inner peripheral surface 5 is the minimum. The closer to the central portion C, the smaller the volume ratio of the soft bearing material 8 accommodated in the circumferential groove 6 in the bearing alloy layer 10. Therefore, during the operation of the internal combustion engine, the load applied from the crank shaft 20 to the inner peripheral surfaces 5 of the half-split bearings 2 and 3 is maximum near the central portion C in the circumferential direction of the half-split bearings 2 and 3. In the vicinity of the central portion C in the circumferential direction, the volume ratio of the bearing alloy in the bearing alloy layer 10 that mainly supports the load increases, so that the load capacity from the crank shaft 20 can be increased.

さらに、半割軸受２，３は、内周面５の周方向の全長に亘って、軸線方向に軸受合金層１０の軸受合金と、軟質軸受材料８を収容した周方向溝６とが交互に配置されている。このため、半割軸受２，３の周方向端部Ｅ付近において周方向溝６内の軟質軸受材料８に埋収されなかった油に含まれる異物（埋収された異物に対して小さい）が、半割軸受２，３の内周面５の何れの位置に送られても、その異物を周方向溝６内の軟質軸受材料８に埋収させることができるので、内周面５（軸受合金層１０の軸受合金の表面）の損傷が起き難い。本発明とは異なり、例えば、周方向溝６を半割軸受２，３の周方向端面７付近の内周面５のみに形成する構成とした場合、周方向溝６を形成しない領域の内周面５は、異物による焼付等の損傷が起き易い。 Further, in the half-split bearings 2 and 3, the bearing alloy of the bearing alloy layer 10 and the circumferential groove 6 accommodating the soft bearing material 8 are alternately arranged in the axial direction over the entire length of the inner peripheral surface 5 in the circumferential direction. Have been placed. Therefore, foreign matter (smaller than the buried foreign matter) contained in the oil that was not embedded in the soft bearing material 8 in the circumferential groove 6 near the circumferential end E of the half-split bearings 2 and 3 is present. Regardless of the position of the inner peripheral surface 5 of the half-split bearings 2 and 3, the foreign matter can be embedded in the soft bearing material 8 in the circumferential groove 6, so that the inner peripheral surface 5 (bearing) Damage to the surface of the bearing alloy of the alloy layer 10) is unlikely to occur. Unlike the present invention, for example, when the circumferential groove 6 is formed only on the inner peripheral surface 5 near the circumferential end faces 7 of the half-split bearings 2 and 3, the inner circumference of the region where the circumferential groove 6 is not formed is formed. The surface 5 is liable to be damaged by foreign matter such as seizure.

また、図３に示すように、周方向溝６は、軸受合金層１０内に形成される。周方向溝６の深さＤは、半割軸受２，３の周方向中央部Ｃにおいて０．００５～０．０２０ｍｍ、半割軸受２，３の周方向端部Ｅにおいて０．０２０～０．０４０ｍｍに設定し、半割軸受２，３の内周面５の周方向中央部Ｃにおいて最小となるようにすることが好ましい。さらに、周方向溝６は、半割軸受２，３の内周面５の周方向中央部Ｃから周方向端部Ｅに向かって、単位円周角度当りの深さが３％以上増加するように次第に深くすることが好ましい。なお、周方向溝６の深さＤは、上記の寸法に限定されないで、他の寸法に変更することもできる。また、本実施例の周方向溝６は、半割軸受２，３の周方向と平行に延びているが、半割軸受２，３の周方向に対し３°以下で傾いていてもよい。 Further, as shown in FIG. 3, the circumferential groove 6 is formed in the bearing alloy layer 10. The depth D of the circumferential groove 6 is 0.005 to 0.020 mm at the circumferential central portion C of the half-split bearings 2 and 3, and 0.020 to 0.020 mm at the circumferential end E of the half-split bearings 2 and 3. It is preferable to set it to 040 mm so that it is minimized at the central portion C in the circumferential direction of the inner peripheral surfaces 5 of the half-split bearings 2 and 3. Further, the circumferential groove 6 has a depth per unit circumferential angle increased by 3% or more from the circumferential central portion C of the inner peripheral surfaces 5 of the half-split bearings 2 and 3 toward the circumferential end portion E. It is preferable to gradually deepen it. The depth D of the circumferential groove 6 is not limited to the above dimensions, and may be changed to other dimensions. Further, although the circumferential groove 6 of this embodiment extends in parallel with the circumferential direction of the half-split bearings 2 and 3, it may be tilted by 3 ° or less with respect to the circumferential direction of the half-split bearings 2 and 3.

また、図３に示すように、周方向溝６の幅Ｗは、０．０８～０．１２ｍｍに設定することが好ましい。なお、周方向溝６の幅Ｗは、内周面５における周方向溝６の半割軸受２，３の軸線方向での長さを意味する。また、本実施例では、半割軸受２，３に形成される周方向溝６の幅Ｗは、周方向で一定になされている。また、半割軸受２，３の軸線方向における周方向溝６のピッチ（溝間距離）は、０．１～０．３ｍｍ程度に設定することが好ましい。さらに、半割軸受２，３の内周面５における軸受合金層１０の軸受合金の面積率は、５～３０％に設定することが好ましい。このような半割軸受２，３の内周面５においては、半割軸受２，３の軸線方向に対してクランク軸２０からの負荷を主に支える硬質な軸受合金層１０の軸受合金と、軟質軸受材料８を収容した周方向溝６とが交互に配置されており、周方向溝６の幅Ｗ及びピッチが半割軸受２，３の負荷能力に関係している。なお、周方向溝６の幅Ｗ及びピッチ、内周面５における軸受合金層１０の軸受合金の面積率は、上記の寸法および面積率に限定されないで、他の寸法および面積率に変更することもできる。 Further, as shown in FIG. 3, the width W of the circumferential groove 6 is preferably set to 0.08 to 0.12 mm. The width W of the circumferential groove 6 means the length of the circumferential groove 6 on the inner peripheral surface 5 in the axial direction of the half bearings 2 and 3. Further, in this embodiment, the width W of the circumferential groove 6 formed in the half-split bearings 2 and 3 is made constant in the circumferential direction. Further, the pitch (distance between grooves) of the circumferential grooves 6 in the axial direction of the half-split bearings 2 and 3 is preferably set to about 0.1 to 0.3 mm. Further, the area ratio of the bearing alloy of the bearing alloy layer 10 on the inner peripheral surfaces 5 of the half-split bearings 2 and 3 is preferably set to 5 to 30%. In the inner peripheral surface 5 of the half-split bearings 2 and 3, the bearing alloy of the hard bearing alloy layer 10 that mainly supports the load from the crank shaft 20 in the axial direction of the half-split bearings 2 and 3 and the bearing alloy. Circumferential grooves 6 accommodating the soft bearing material 8 are alternately arranged, and the width W and pitch of the circumferential grooves 6 are related to the load capacity of the half-split bearings 2 and 3. The width W and pitch of the circumferential groove 6 and the area ratio of the bearing alloy of the bearing alloy layer 10 on the inner peripheral surface 5 are not limited to the above dimensions and area ratio, but may be changed to other dimensions and area ratio. You can also.

また、本実施例では、周方向溝６の横断面形状として矩形の溝を例として示したが、これに限定されず、例えば、周方向溝６の軸線方向の両側に面取を施した逆台形形状や、他の形状としてもよい。また、半割軸受２，３の内周面５の周方向端部Ｅには、半割軸受２、３の軸線方向の全長に亘って傾斜面状に除去した面取を施すこともでき、この場合、周方向溝６の周方向端部は、面取面内に位置する（面取を形成しなかった場合、周方向溝６の周方向端部は、内周面５の周方向端部Ｅに位置する）ようにしてもよい。 Further, in this embodiment, a rectangular groove is shown as an example of the cross-sectional shape of the circumferential groove 6, but the present invention is not limited to this, and for example, the reverse is performed by chamfering both sides of the circumferential groove 6 in the axial direction. It may be a trapezoidal shape or another shape. Further, the circumferential end E of the inner peripheral surface 5 of the half-split bearings 2 and 3 can be chamfered so as to be removed in an inclined surface shape over the entire length of the half-split bearings 2 and 3 in the axial direction. In this case, the circumferential end of the circumferential groove 6 is located in the chamfered surface (when no chamfer is formed, the circumferential end of the circumferential groove 6 is the circumferential end of the inner peripheral surface 5). It may be located in part E).

（実施例２の半割軸受の構成）
以上、実施例１に係る半割軸受２，３に形成される周方向溝６の幅Ｗが一定のものについて説明したが、次に、実施例１とは周方向溝６の幅Ｗが異なる形状のものが半割軸受２，３に形成されている実施例２について図４を参照して説明する。図４は、下半割軸受３の内周面５の周方向中央部Ｃから周方向端部Ｅ側に向かって周方向溝６の幅Ｗが次第に広く形成されている下半割軸受３の内周面５側から見た平面図である。なお、図４には、半割軸受２，３のうち下半割軸受３を例として示すが、上半割軸受２にも下半割軸受３と同じ形状の周方向溝６が形成されている。また、実施例１と同じ機能を奏する部材については、実施例１と同じ符号が付してある。 (Structure of half-split bearing of Example 2)
The width W of the circumferential groove 6 formed in the half-split bearings 2 and 3 according to the first embodiment has been described above. Next, the width W of the circumferential groove 6 is different from that of the first embodiment. Example 2 in which the shape is formed on the half-split bearings 2 and 3 will be described with reference to FIG. FIG. 4 shows the lower half-split bearing 3 in which the width W of the circumferential groove 6 is gradually widened from the circumferential central portion C of the inner peripheral surface 5 of the lower half-split bearing 3 toward the circumferential end E side. It is a plan view seen from the inner peripheral surface 5 side. Note that FIG. 4 shows the lower half split bearing 3 as an example of the half split bearings 2 and 3, but the upper half split bearing 2 is also formed with a circumferential groove 6 having the same shape as the lower half split bearing 3. There is. Further, the members having the same functions as those in the first embodiment are designated by the same reference numerals as those in the first embodiment.

図４に示すように、実施例２に係る半割軸受２，３の内周面５には、周方向溝６の深さＤについて実施例１と同一に形成されているが、周方向溝６の幅Ｗが半割軸受２，３の内周面５の周方向中央部Ｃにおいて最小となり、半割軸受２，３の内周面５の周方向端部Ｅ側に向かって次第に広く形成されている。また、半割軸受２，３の内周面５の周方向端部Ｅにおける周方向溝６の幅Ｗ１は、周方向中央部Ｃにおける周方向溝６の幅Ｗに対し１．２～２倍広くなる（Ｗ１／Ｗ＝１．２～２）ことが好ましい。このように、本実施例の半割軸受２，３は、内周面５の周方向端部Ｅ付近での周方向溝６の幅Ｗ１が広くなることで、内周面５の周方向端部Ｅ付近では、軟質軸受材料８を収容した周方向溝６に異物を埋収することが可能な許容量がさらに大きくなっている。したがって、軟質軸受材料８を収容した周方向溝６において周方向端部付近に局部的に異物が集中した埋収があっても、その異物は、さらに、周方向溝６内の軟質軸受材料８に完全に埋収され易く、内周面５（軟質軸受材料８の表面）よりも径方向の内側に突出し難くすることができる。 As shown in FIG. 4, the inner peripheral surfaces 5 of the half-split bearings 2 and 3 according to the second embodiment are formed with the same depth D of the circumferential groove 6 as in the first embodiment, but the circumferential groove is formed. The width W of 6 is minimized at the circumferential center C of the inner peripheral surfaces 5 of the half-split bearings 2 and 3, and is gradually wider toward the circumferential end E side of the inner peripheral surfaces 5 of the half-split bearings 2 and 3. Has been done. Further, the width W1 of the circumferential groove 6 at the circumferential end E of the inner peripheral surfaces 5 of the half-split bearings 2 and 3 is 1.2 to 2 times the width W of the circumferential groove 6 at the circumferential central portion C. It is preferable that it becomes wider (W1 / W = 1.2 to 2). As described above, in the half-split bearings 2 and 3 of the present embodiment, the width W1 of the circumferential groove 6 near the circumferential end E of the inner peripheral surface 5 is widened, so that the circumferential end of the inner peripheral surface 5 is widened. In the vicinity of the portion E, the allowable amount capable of embedding foreign matter in the circumferential groove 6 accommodating the soft bearing material 8 is further increased. Therefore, even if foreign matter is locally concentrated and buried near the peripheral end portion in the circumferential groove 6 accommodating the soft bearing material 8, the foreign matter is further present in the flexible bearing material 8 in the circumferential groove 6. It is easy to be completely buried in the bearing, and it is possible to make it less likely to protrude inward in the radial direction than the inner peripheral surface 5 (the surface of the soft bearing material 8).

（実施例３の半割軸受の構成）
次に、実施例１に係る周方向溝６が形成される半割軸受２，３に対し、さらに半割軸受２，３の内周面５の周方向端部Ｅにクラッシュリリーフ１１が形成されている実施例３について図５を参照して説明する。図５は、半割軸受２，３の内周面５の周方向両端部Ｅ側にクラッシュリリーフ１１が形成されているすべり軸受１の正面図（Ａ）と、上半割軸受２と下半割軸受３の内周面５側から見た平面図（Ｂ）である。なお、実施例１と同じ機能を奏する部材については、実施例１と同じ符号が付してある。また、実施例３では、実施例１に係る形状の周方向溝６が形成される半割軸受２，３に対してクラッシュリリーフ１１を形成する例を示すが、実施例２に係る形状の周方向溝６が形成される半割軸受２，３に対してクラッシュリリーフ１１を形成してもよい。 (Structure of half-split bearing of Example 3)
Next, with respect to the half-split bearings 2 and 3 in which the circumferential groove 6 according to the first embodiment is formed, a crash relief 11 is further formed at the circumferential end E of the inner peripheral surface 5 of the half-split bearings 2 and 3. The third embodiment will be described with reference to FIG. FIG. 5 shows a front view (A) of a slide bearing 1 in which a crash relief 11 is formed on both ends E side of the inner peripheral surfaces 5 of the half-split bearings 2 and 3 in the circumferential direction, and an upper half-split bearing 2 and a lower half. It is a plan view (B) seen from the inner peripheral surface 5 side of a plain bearing 3. The members having the same functions as those in the first embodiment are designated by the same reference numerals as those in the first embodiment. Further, in the third embodiment, an example in which the crush relief 11 is formed with respect to the half-split bearings 2 and 3 in which the circumferential groove 6 having the shape according to the first embodiment is formed is shown, but the circumferential shape according to the second embodiment is formed. The crash relief 11 may be formed on the half bearings 2 and 3 in which the directional groove 6 is formed.

図５に示すように、実施例３に係る半割軸受２，３の内周面５の周方向端部Ｅ側には、クラッシュリリーフ１１が形成されている。なお、クラッシュリリーフ１１とは、半割軸受２，３の周方向端面７に近い部分の半割軸受２，３の壁厚を内周面５側で除去することによって形成された、半割軸受２，３の周方向中央部Ｃを含む内周面５の曲率中心とは異なる曲率中心を有する減厚領域（周方向端面７に向かって厚さを減じた領域を指し、ＳＡＥ Ｊ５０６（項目３．２６、項目６．４参照）、ＤＩＮ１４９７、§３．２で規定されるとおりである）を意味する。このように、半割軸受２，３の周方向端面７（周方向端部Ｅ）付近における内周面（クラッシュリリーフ面１１ａ）とクランク軸２０の表面とを離間させる隙間を形成することにより、油溝４から該隙間に流れて来た異物が、該隙間の軸線方向へも流れ、複数の周方向溝６に分散し埋収されることで、特定の周方向溝６に異物が集中し埋収されることを防ぐことができる。 As shown in FIG. 5, a crash relief 11 is formed on the circumferential end E side of the inner peripheral surface 5 of the half-split bearings 2 and 3 according to the third embodiment. The crush relief 11 is a half-split bearing formed by removing the wall thickness of the half-split bearings 2 and 3 in a portion close to the circumferential end surface 7 of the half-split bearings 2 and 3 on the inner peripheral surface 5 side. A thickened region having a center of curvature different from the center of curvature of the inner peripheral surface 5 including the central portion C in the circumferential direction (refers to a region whose thickness is reduced toward the peripheral end surface 7), SAE J506 (item 3). .26, see item 6.4), DIN1497, as specified in §3.2). In this way, by forming a gap that separates the inner peripheral surface (crash relief surface 11a) and the surface of the crank shaft 20 in the vicinity of the circumferential end surface 7 (circumferential end E) of the half-split bearings 2 and 3, the gap is formed. The foreign matter that has flowed from the oil groove 4 into the gap also flows in the axial direction of the gap, and is dispersed and buried in the plurality of circumferential grooves 6, so that the foreign matter is concentrated in the specific circumferential groove 6. It can be prevented from being buried.

なお、クラッシュリリーフ１１の形成部における周方向溝６の深さＤは、クラッシュリリーフ１１を形成しなかった場合の仮想の内周面（周方向中央部Ｃを含む内周面５をクラッシュリリーフ１１の形成部に延長した仮想の内周面）から周方向溝６の底面までの長さとして定義される。また、クラッシュリリーフ１１の形成部における複数の周方向溝６の幅Ｗは、クラッシュリリーフ１１を形成しなかった場合の仮想の内周面における幅として定義される。また、半割軸受２，３の内周面５の周方向端部Ｅ付近に、クラッシュリリーフ１１を形成する場合、周方向溝６の周方向端部は、クラッシュリリーフ面１１ａ内に位置する（クラッシュリリーフ１１を形成しなかった場合、周方向溝６の周方向端部は、内周面５の周方向端部Ｅに位置する）ようにしてもよい。 The depth D of the circumferential groove 6 in the formed portion of the crash relief 11 is a virtual inner peripheral surface (the inner peripheral surface 5 including the central portion C in the circumferential direction) when the crash relief 11 is not formed. It is defined as the length from the virtual inner peripheral surface extending to the forming portion of the circumferential groove 6 to the bottom surface of the circumferential groove 6. Further, the width W of the plurality of circumferential grooves 6 in the forming portion of the crash relief 11 is defined as the width on the virtual inner peripheral surface when the crash relief 11 is not formed. Further, when the crush relief 11 is formed in the vicinity of the circumferential end E of the inner peripheral surfaces 5 of the half-split bearings 2 and 3, the circumferential end of the circumferential groove 6 is located in the crush relief surface 11a ( If the crash relief 11 is not formed, the circumferential end of the circumferential groove 6 may be located at the circumferential end E of the inner peripheral surface 5).

なお、実施例１～実施例３では、本発明を内燃機関のクランク軸２０のジャーナル部用の半割軸受２，３に適用した例で説明したが、本発明はクランク軸２０のクランクピン用の半割軸受にも適用することができる。また、半割軸受２，３は、防錆のために全表面にＳｎ等のフラッシュメッキ（厚さ２．５μｍ以下）を形成することができる。 In Examples 1 to 3, the present invention has been described by applying the present invention to the half-split bearings 2 and 3 for the journal portion of the crank shaft 20 of the internal combustion engine, but the present invention has been described for the crank pin of the crank shaft 20. It can also be applied to half-split bearings. Further, the half-split bearings 2 and 3 can be flash-plated (thickness 2.5 μm or less) such as Sn on the entire surface for rust prevention.

１ すべり軸受
２ 上半割軸受
３ 下半割軸受
４ 油溝
４ａ 油穴
５ 内周面
６ 周方向溝
７ 周方向端面
８ 軟質軸受材料
９ 鋼裏金層
１０ 軸受合金層
１１ クラッシュリリーフ
１１ａ クラッシュリリーフ面
２０ クランク軸
Ｃ 周方向中央部
Ｅ 周方向端部
Ｄ 周方向溝の深さ
Ｗ 周方向溝の幅 1 Plain bearing 2 Upper half-split bearing 3 Lower half-split bearing 4 Oil groove 4a Oil hole 5 Inner peripheral surface 6 Circumferential groove 7 Circumferential end surface 8 Flexible bearing material 9 Steel back metal layer 10 Bearing alloy layer 11 Crash relief 11a Crash relief surface 20 Crank shaft C Circumferential center E Circumferential end D Circumferential groove depth W Circumferential groove width

Claims (3)

鋼裏金層と軸受合金層とを有し、且つ２個を組み合せて円筒形を構成する半割形状に形成された内燃機関のクランク軸用の半割軸受であって、
前記半割軸受の内周面には、軸線方向に前記軸受合金層の軸受合金と交互に配置され、且つ円周方向の全周にわたって延在する複数の周方向溝を形成すると共に、該周方向溝に軟質軸受材料を収容して内周面が面一となるように形成された内燃機関のクランク軸用の半割軸受において、
前記周方向溝の深さは、前記半割軸受の内周面の周方向中央部において最小となり、前記半割軸受の内周面の周方向両端部に向かって次第に深く形成されていることを特徴とする内燃機関のクランク軸用の半割軸受。 A half-split bearing for a crank shaft of an internal combustion engine, which has a steel back metal layer and a bearing alloy layer, and is formed into a half-split shape forming a cylindrical shape by combining the two.
On the inner peripheral surface of the half-split bearing, a plurality of circumferential grooves are alternately arranged in the axial direction with the bearing alloy of the bearing alloy layer and extend over the entire circumference in the circumferential direction, and the circumference thereof is formed. In a half-split bearing for a crank shaft of an internal combustion engine, which is formed so that the inner peripheral surface is flush with the soft bearing material accommodated in the directional groove.
The depth of the circumferential groove is the minimum in the circumferential central portion of the inner peripheral surface of the half-split bearing, and is gradually formed deeper toward both ends in the circumferential direction of the inner peripheral surface of the half-split bearing. A half-split bearing for the crank shaft of an internal combustion engine. 前記周方向溝の幅は、前記半割軸受の内周面の周方向中央部において最小となり、前記半割軸受の内周面の周方向両端部に向かって次第に広く形成されていることを特徴とする請求項１記載の内燃機関のクランク軸用の半割軸受。 The width of the circumferential groove is the minimum in the circumferential central portion of the inner peripheral surface of the half-split bearing, and is characterized in that the width is gradually widened toward both ends in the circumferential direction of the inner peripheral surface of the half-split bearing. The half bearing for the crank shaft of the internal combustion engine according to claim 1. 前記半割軸受の内周面の周方向両端部には、クラッシュリリーフが形成されていることを特徴とする請求項１又は請求項２記載の内燃機関のクランク軸用の半割軸受。 The half-split bearing for a crank shaft of an internal combustion engine according to claim 1 or 2, wherein crush relief is formed at both ends of the inner peripheral surface of the half-split bearing in the circumferential direction.

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