JP2019157984A - Bearing device of crankshaft of internal combustion engine - Google Patents

Abstract

To provide a bearing device which hardly causes the deposition of product materials between a back metal-layer surface of halved bearings and a semi-cylindrical face of a bearing holding hole, and can prevent the damage of the halved bearings.SOLUTION: On a back metal-layer surface 82 of halved bearings 31, 32, a protrusive curved face is formed over a peripheral entire length of the halved bearings 31, 32 toward the outside of a radial direction from a virtual line M for connecting both end parts of the halved bearings 31, 32 in an axial line direction at the back metal-layer surface 82. Therefore, since the protrusive curved face formed at the halved bearings 31, 32 selectively imparts pressure discharged to the outside of a clearance to engine oil in the clearance and the product materials, the engine oil and the product materials are hardly deposited in the clearance, and the damage of the halved bearings 31, 32 can be suitably prevented.SELECTED DRAWING: Figure 4

Description

本発明は、内燃機関のクランク軸を支承するための軸受装置に関する。   The present invention relates to a bearing device for supporting a crankshaft of an internal combustion engine.

内燃機関のクランク軸は、そのジャーナル部において、主軸受ハウジングの軸受保持穴に装着された主軸受に支承される。主軸受に対しては、オイルポンプによって吐出された潤滑油が、シリンダブロック壁内に形成されたオイルギャラリーから主軸受の壁に形成された貫通口を通じて、主軸受の内周面に沿って形成された潤滑油溝内に送り込まれる。また、ジャーナル部の直径方向には第１潤滑油路が貫通形成され、この第１潤滑油路の両端開口が主軸受の潤滑油溝と連通するようになっている。さらに、ジャーナル部の第１潤滑油路から、クランクアーム部を通る第２潤滑油路が分岐して形成され、この第２潤滑油路が、クランクピンの直径方向に貫通形成された第３潤滑油路に連通している。このようにして、シリンダブロック壁内のオイルギャラリーから貫通口を通じて主軸受の内周面に形成された潤滑油溝内に送り込まれた潤滑油は、第１潤滑油路、第２潤滑油路及び第３潤滑油路を経て、第３潤滑油路の末端に開口した吐出口から、クランクピン部とコンロッド軸受ハウジングの軸受保持穴に装着されたコンロッド軸受の摺動面間に供給される（例えば特許文献１参照）。   The crankshaft of the internal combustion engine is supported by a main bearing mounted in a bearing holding hole of the main bearing housing at a journal portion thereof. For the main bearing, the lubricating oil discharged by the oil pump is formed along the inner peripheral surface of the main bearing from the oil gallery formed in the cylinder block wall through the through-hole formed in the wall of the main bearing. Into the lubricating oil groove. Further, a first lubricating oil passage is formed through in the diameter direction of the journal portion, and both end openings of the first lubricating oil passage communicate with the lubricating oil groove of the main bearing. Further, a second lubricating oil passage that passes through the crank arm portion is formed by branching from the first lubricating oil passage of the journal portion, and this second lubricating oil passage is formed to penetrate in the diameter direction of the crank pin. It communicates with the oil passage. Thus, the lubricating oil sent from the oil gallery in the cylinder block wall into the lubricating oil groove formed on the inner peripheral surface of the main bearing through the through-hole is the first lubricating oil passage, the second lubricating oil passage, Through the third lubricating oil passage, the supply is made between the sliding surface of the connecting rod bearing mounted in the bearing holding hole of the connecting rod bearing housing from the discharge port opened at the end of the third lubricating oil passage (for example, Patent Document 1).

従来から、主軸受及びコンロッド軸受には、一対の半割軸受から構成されるすべり軸受が採用されており、半割軸受は、裏金層と摺動層から構成される。また、主軸受ハウジング及びコンロッド軸受ハウジングは、第１の分割体と第２の分割体からなり、第１の分割体と第２の分割体は、それぞれが半円筒面を有し、主軸受ハウジング及びコンロッド軸受ハウジングの軸受保持穴は、一対の半円筒面が組み合わされることで円筒形状に形成される。そして、一対の半割軸受は、一対の半円筒面に装着され軸受保持穴に保持されている。   Conventionally, a slide bearing including a pair of half bearings has been adopted as the main bearing and the connecting rod bearing, and the half bearing includes a back metal layer and a sliding layer. The main bearing housing and the connecting rod bearing housing include a first divided body and a second divided body, and each of the first divided body and the second divided body has a semicylindrical surface. The bearing holding hole of the connecting rod bearing housing is formed in a cylindrical shape by combining a pair of semi-cylindrical surfaces. The pair of half bearings are mounted on the pair of semi-cylindrical surfaces and are held in the bearing holding holes.

特開平８−２７７８３１号公報JP-A-8-277831 特開２０１１−２３１９０３号公報JP 2011-231903 A

従来の内燃機関の構造的な課題として、半割軸受の裏金層表面と軸受保持穴の半円筒面との間にエンジンオイル及び不完全燃焼生成物（カーボンスラッジ等。以下、不完全燃焼生成物を生成物と記載する。）が堆積されやすく、エンジンオイル及び生成物の堆積に起因した半割軸受の損傷が発生しやすいことが挙げられる。   As a structural problem of a conventional internal combustion engine, engine oil and incomplete combustion products (carbon sludge, etc., hereinafter referred to as incomplete combustion products) are formed between the back metal layer surface of the half bearing and the semicylindrical surface of the bearing holding hole. Is described as a product), and damage to the half bearing caused by engine oil and product deposition is likely to occur.

具体的には、半割軸受は、多くの場合、プレス加工により平板から半円筒形状に成形されるが、プレス加工時の残留応力の影響により、半割軸受の軸線方向の裏金層表面は、摺動層側（径方向内側）に向かって凹状曲面に形成されている。また、内燃機関の運転に伴い発生する動荷重により軸受保持穴が変形した際には、半割軸受の裏金層表面と軸受保持穴の半円筒面との間には隙間が生成され、その隙間には周囲のエンジンオイル及び生成物が吸入されるが、従来の半割軸受は、裏金層表面に凹状曲面を有することから、隙間が半割軸受の軸線方向中央側に選択的に形成されてしまい、エンジンオイル及び生成物が隙間から排出されにくく、隙間内には次第に排出されないエンジンオイル及び生成物が堆積される。そして、堆積されたエンジンオイル及び生成物は、半割軸受の裏金層表面を押し上げ、堆積されたエンジンオイル及び生成物の径方向内側に位置する半割軸受の摺動層表面が部分的に***される。このため、***された摺動層表面は、クランク軸との直接接触の機会を増大させ、接触抵抗による発熱が増大し、最悪の場合には焼付き損傷に至る。   Specifically, in many cases, the half bearing is formed from a flat plate into a semi-cylindrical shape by pressing, but due to the influence of residual stress during pressing, the surface of the back bearing layer in the axial direction of the half bearing is A concave curved surface is formed toward the sliding layer side (inner side in the radial direction). Further, when the bearing holding hole is deformed by the dynamic load generated during the operation of the internal combustion engine, a gap is generated between the back metal layer surface of the half bearing and the semi-cylindrical surface of the bearing holding hole. The surrounding engine oil and products are sucked in, but the conventional half bearing has a concave curved surface on the surface of the back metal layer, so that a gap is selectively formed on the axial center side of the half bearing. Therefore, engine oil and products are not easily discharged from the gap, and engine oil and products that are not gradually discharged are accumulated in the gap. Then, the accumulated engine oil and product push up the surface of the half-bearing back metal layer, and the surface of the half-bearing sliding layer located inside the accumulated engine oil and product is partially raised. Is done. For this reason, the raised sliding layer surface increases the chance of direct contact with the crankshaft, heat generation due to contact resistance increases, and in the worst case, seizure damage occurs.

また、特許文献２においては、摺動層と、第１の裏金層と、摺動層と第１の裏金層の間に設けられる第２の裏金層と、から成る一対の半割軸受が提供されている。ここで、第２の裏金層の熱膨張率は、第１の裏金層の熱膨張率よりも高いことを特徴としている。本構成によれば、第１の裏金層と第２の裏金層の熱膨張率の差から、半割軸受の温度を変化させることで半割軸受の軸線方向の形状を変化させることが可能となる。即ち、半割軸受が低温であるときには、半割軸受の裏金層表面が裏金層側に向かう凸状曲面を有し、半割軸受が高温であるときには、半割軸受の裏金層表面が摺動層側に向かう凹状曲面を有することとなる。しかしながら、本構成によれば、一対の半割軸受が高温状態で軸受保持穴に保持された状態で、動荷重により軸受保持穴に変形が生じた際には、一対の半割軸受の裏金層表面が摺動層側に向かう凹状曲面を有することから、軸受保持穴の変形に伴い発生する隙間が一対の半割軸受の軸線方向中央側に選択的に形成されてしまい、依然としてエンジンオイル及び生成物を隙間から排出しにくい構造であることに変わりはなく、上記した構造的な課題は根本的に解決されていない。   Patent Document 2 provides a pair of half bearings including a sliding layer, a first back metal layer, and a second back metal layer provided between the sliding layer and the first back metal layer. Has been. Here, the thermal expansion coefficient of the second back metal layer is characterized by being higher than the thermal expansion coefficient of the first back metal layer. According to this configuration, it is possible to change the shape of the half bearing in the axial direction by changing the temperature of the half bearing from the difference in coefficient of thermal expansion between the first backing metal layer and the second backing metal layer. Become. That is, when the half bearing is at a low temperature, the back metal layer surface of the half bearing has a convex curved surface toward the back metal layer, and when the half bearing is at a high temperature, the back metal layer surface of the half bearing slides. It will have a concave curved surface which goes to the layer side. However, according to this configuration, when the pair of half bearings are held in the bearing holding holes at a high temperature and the bearing holding holes are deformed by a dynamic load, the back metal layer of the pair of half bearings Since the surface has a concave curved surface toward the sliding layer side, a gap generated with the deformation of the bearing holding hole is selectively formed on the center side in the axial direction of the pair of half bearings. There is no change in the structure that makes it difficult to discharge objects from the gap, and the above structural problems have not been fundamentally solved.

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、半割軸受の裏金層表面と軸受保持穴の半円筒面との隙間にエンジンオイル及び生成物が堆積されにくく、半割軸受の損傷を防止することが可能な軸受装置を提供することにある。   The present invention has been made in view of the above-described circumstances, and its object is to prevent engine oil and products from being deposited in the gap between the back metal layer surface of the half bearing and the semi-cylindrical surface of the bearing holding hole. An object of the present invention is to provide a bearing device capable of preventing damage to a half bearing.

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、内燃機関のクランク軸と、該クランク軸を回転自在に支持するすべり軸受と、該すべり軸受を保持する軸受保持穴を有する軸受ハウジングと、から成る軸受装置において、前記すべり軸受は、各々が裏金層及び摺動層を有する一対の半割軸受から構成され、前記軸受ハウジングは、各々が半円筒面を有する第１の分割体と第２の分割体とから構成され、前記軸受保持穴は、一対の半円筒面が組み合わされることで円筒形状に形成されると共に、該半円筒面が前記軸受保持穴の軸線方向と平行になされ、前記一対の半割軸受は、前記一対の半円筒面に装着され前記軸受保持穴に保持され、前記軸受保持穴に非装着状態の半割軸受は、最小で、該半割軸受の周方向両端面から周方向中央部側に向かうそれぞれ円周角度４５°の位置Ｐ１を基準として−５°〜＋５°の円周角度の範囲、最大で、該半割軸受の周方向全長に亘る範囲において、前記裏金層表面が、該裏金層表面における前記半割軸受の軸線方向両端部を結ぶ仮想線Ｍから径方向の外側に向かう凸状曲面を有し、前記軸受保持穴に前記一対の半割軸受が装着された状態では、前記裏金層表面が、前記軸受保持穴の軸線方向と平行となることを特徴とする。   In order to achieve the above object, in the invention according to claim 1, a bearing having a crankshaft of an internal combustion engine, a slide bearing that rotatably supports the crankshaft, and a bearing holding hole that holds the slide bearing. In the bearing device comprising the housing, the sliding bearing is composed of a pair of half bearings each having a back metal layer and a sliding layer, and the bearing housing is a first divided body each having a semicylindrical surface. The bearing holding hole is formed in a cylindrical shape by combining a pair of semi-cylindrical surfaces, and the semi-cylindrical surface is parallel to the axial direction of the bearing holding hole. The pair of half bearings are mounted on the pair of semi-cylindrical surfaces and held in the bearing holding holes, and the half bearings not mounted in the bearing holding holes are at least the circumference of the half bearings. Direction from both end faces The surface of the back metal layer in a range of a circumferential angle of −5 ° to + 5 ° with respect to a position P1 having a circumferential angle of 45 ° toward the central portion, at most, in a range covering the entire circumferential length of the half bearing. However, it has a convex curved surface that extends radially outward from an imaginary line M connecting the axial end portions of the half bearing on the back metal layer surface, and the pair of half bearings are mounted in the bearing holding holes. In the state, the surface of the back metal layer is parallel to the axial direction of the bearing holding hole.

請求項２に係る発明においては、請求項１記載の軸受装置において、前記凸状曲面の頂部は、前記半割軸受の軸線方向の中央部に位置することを特徴とする。   According to a second aspect of the present invention, in the bearing device according to the first aspect, the top portion of the convex curved surface is located at a central portion in the axial direction of the half bearing.

請求項３に係る発明においては、請求項１または請求項２記載の軸受装置において、前記凸状曲面の高さＨは、０．００１〜０．１ｍｍであることを特徴とする。   The invention according to claim 3 is the bearing device according to claim 1 or 2, characterized in that a height H of the convex curved surface is 0.001 to 0.1 mm.

請求項４に係る発明においては、請求項１乃至請求項３のいずれに記載の軸受装置において、前記半割軸受は、軸受壁厚が該半割軸受の軸線方向に亘って一定であることを特徴とする。   According to a fourth aspect of the present invention, in the bearing device according to any one of the first to third aspects, the bearing wall thickness of the half bearing is constant over the axial direction of the half bearing. Features.

請求項５に係る発明においては、請求項１乃至請求項３のいずれかに記載の軸受装置において、前記半割軸受は、該半割軸受の軸線方向の中央部を含み形成され、軸受壁厚が一定である平滑領域と、該平滑領域の軸線方向両側に形成され、軸受壁厚が該半割軸受の軸線方向端部側に向かって小さくなる傾斜領域と、を有することを特徴とする。   According to a fifth aspect of the present invention, in the bearing device according to any one of the first to third aspects, the half bearing is formed including a central portion in the axial direction of the half bearing, and has a bearing wall thickness. In which the bearing wall thickness is reduced toward the axial direction end portion side of the half bearing.

請求項６に係る発明においては、請求項１乃至請求項５のいずれかに記載の軸受装置において、前記すべり軸受は、前記クランク軸のクランクピン部を支承するコンロッド軸受であることを特徴とする。   According to a sixth aspect of the present invention, in the bearing device according to any one of the first to fifth aspects, the sliding bearing is a connecting rod bearing that supports a crankpin portion of the crankshaft. .

請求項７に係る発明においては、請求項１乃至請求項５のいずれかに記載の軸受装置において、前記すべり軸受は、前記クランク軸のジャーナル部を支承する主軸受であることを特徴とする。   The invention according to claim 7 is the bearing device according to any one of claims 1 to 5, wherein the slide bearing is a main bearing that supports a journal portion of the crankshaft.

請求項１に係る発明においては、内燃機関の運転に伴い発生する動荷重により、軸受保持穴が変形した際には、半割軸受の裏金層表面と軸受保持穴の半円筒面との間に隙間が生成され、同部には周囲のエンジンオイル及び生成物が吸入されるが、本発明の半割軸受が有する凸状曲面は、隙間内のエンジンオイル及び生成物に対して隙間外に排出される圧力を選択的に与えることから、隙間内にエンジンオイル及び生成物が堆積されにくく、好適に半割軸受の損傷を防止することができる。   In the invention according to claim 1, when the bearing holding hole is deformed due to a dynamic load generated during operation of the internal combustion engine, the space between the back metal layer surface of the half bearing and the semi-cylindrical surface of the bearing holding hole. A gap is generated, and surrounding engine oil and products are sucked into the same, but the convex curved surface of the half bearing according to the present invention is discharged outside the gap with respect to the engine oil and products in the gap. Since the applied pressure is selectively applied, engine oil and products are not easily accumulated in the gap, and damage to the half bearing can be suitably prevented.

また、請求項２に係る発明においては、一般的に半割軸受の軸線方向中央部が最も高い負荷を受けるが、凸状曲面の頂部が半割軸受の軸線方向の中央部に位置することから、半割軸受の裏金層表面と軸受保持穴の半円筒面の密着が軸線方向中央部で最も維持されやすく、同部はエンジンオイル及び生成物が吸入される可能性が最も低い。このため、同部にエンジンオイル及び生成物が堆積されにくく、好適に半割軸受の損傷を防止することができる。   Moreover, in the invention which concerns on Claim 2, although the axial direction center part of a half bearing generally receives the highest load, since the top part of a convex curved surface is located in the axial direction center part of a half bearing. The close contact between the back bearing layer surface of the half bearing and the semi-cylindrical surface of the bearing holding hole is most easily maintained at the central portion in the axial direction, and the portion is least likely to be inhaled with engine oil and products. For this reason, engine oil and a product are hard to accumulate in the same part, and damage to a half bearing can be prevented suitably.

また、請求項３に係る発明においては、凸状曲面の高さＨが最小で０．００１ｍｍ以上であることで、隙間内のエンジンオイル及び生成物に対し、半割軸受及び軸受保持穴の半円筒面の軸線方向端部側に向かう圧力を働かせることができる。また、凸状曲面の高さＨが大きくなると、エンジンオイル及び生成物に働く圧力は大きくなるが、背反として、半割軸受の軸線方向端部が、クランクピン部側に近づくことになり、クランクピン部側との接触の機会が増大することから、凸状曲面の高さＨは、最大で０．１ｍｍ以下に抑えることが望ましい。   In the invention according to claim 3, the height H of the convex curved surface is at least 0.001 mm, so that the half of the half bearing and the bearing holding hole are half of the engine oil and the product in the gap. A pressure directed toward the end of the cylindrical surface in the axial direction can be applied. Further, as the height H of the convex curved surface increases, the pressure acting on the engine oil and the product increases, but as a contradiction, the axial end portion of the half bearing approaches the crankpin portion side, Since the chance of contact with the pin portion side increases, the height H of the convex curved surface is desirably suppressed to 0.1 mm or less at maximum.

また、請求項４に係る発明においては、半割軸受の軸受壁厚が該半割軸受の軸線方向に亘って一定であることで、該半割軸受の摺動層表面に入力されるクランク軸の荷重を摺動層表面の広い範囲に分散させる（面圧を低く抑える）ことができるため、半割軸受への負荷が減少され、好適に半割軸受の損傷を防止することができる。   Further, in the invention according to claim 4, the crankshaft that is input to the sliding layer surface of the half bearing, because the bearing wall thickness of the half bearing is constant over the axial direction of the half bearing. Therefore, the load on the half bearing can be reduced, and damage to the half bearing can be preferably prevented.

また、請求項５に係る発明においては、半割軸受は、該半割軸受の軸線方向の中央部を含み形成され、軸受壁厚が一定である平滑領域と、該平滑領域の軸線方向両側に形成され、軸受壁厚が半割軸受の軸線方向端部側に向かって小さくなる傾斜領域を有するため、半割軸受の軸線方向端部における半割軸受とクランク軸の距離を離すことができ、接触回避により、好適に半割軸受の損傷を防止することができる。   In the invention according to claim 5, the half bearing is formed including a central portion in the axial direction of the half bearing, and has a smooth region having a constant bearing wall thickness, and both sides of the smooth region in the axial direction. Formed and having an inclined region in which the bearing wall thickness decreases toward the axial end of the half bearing, the distance between the half bearing and the crankshaft at the axial end of the half bearing can be separated, By avoiding contact, damage to the half bearing can be suitably prevented.

また、請求項６に係る発明のように、すべり軸受は、クランク軸のクランクピン部を支承するコンロッド軸受として用いることができる。   Further, as in the invention according to claim 6, the slide bearing can be used as a connecting rod bearing for supporting the crankpin portion of the crankshaft.

また、請求項７に係る発明のように、すべり軸受は、クランク軸のジャーナル部を支承する主軸受として用いることができる。   Further, as in the invention according to claim 7, the slide bearing can be used as a main bearing for supporting the journal portion of the crankshaft.

二つの軸受装置を含む構造体を示す図である。It is a figure which shows the structure containing two bearing apparatuses. 半割軸受の構造を示す断面図である。It is sectional drawing which shows the structure of a half bearing. 上図は、半割軸受の摺動層表面から見た図であり、下図は、側面から見た図である。The upper view is a view from the surface of the sliding layer of the half bearing, and the lower view is a view from the side. （Ａ）の上図は、第１実施形態の半割軸受の摺動層表面から見た図であり、（Ａ）の下図は、第１実施形態の半割軸受の軸線方向の断面を示す図である。（Ｂ）の上図は、第２実施形態の半割軸受の摺動層表面から見た図面であり、（Ｂ）の下図は、第２実施形態の半割軸受の軸線方向の断面を示す図である。The upper figure of (A) is the figure seen from the sliding layer surface of the half bearing of 1st Embodiment, and the lower figure of (A) shows the cross section of the axial direction of the half bearing of 1st Embodiment. FIG. The upper figure of (B) is a drawing seen from the sliding layer surface of the half bearing of the second embodiment, and the lower figure of (B) shows a cross section in the axial direction of the half bearing of the second embodiment. FIG. （Ａ）は、半割軸受が軸受保持穴に装着された状態を示す図であり、（Ｂ）は、軸受保持穴の変形時の隙間を示す図である。(A) is a figure which shows the state with which the half bearing was mounted | worn with the bearing holding hole, (B) is a figure which shows the clearance gap at the time of a deformation | transformation of a bearing holding hole. （Ａ）は、隙間にエンジンオイル及び生成物が吸引される状態を示す模式図であり、（Ｂ）は、隙間内をエンジンオイル及び生成物が移動する状態を示す模式図であり、（Ｃ）は、エンジンオイル及び生成物が排出された状態を示す模式図である。(A) is a schematic diagram showing a state where engine oil and products are sucked into the gap, (B) is a schematic diagram showing a state where engine oil and products move in the gap, (C ) Is a schematic view showing a state in which engine oil and products are discharged. 裏金層表面の加工方法の例を示す図である。It is a figure which shows the example of the processing method of the back metal layer surface. 上図は、第３実施形態の半割軸受の摺動層表面から見た図であり、下図は、第３実施形態の半割軸受の軸線方向の断面を示す図である。The upper view is a view seen from the sliding layer surface of the half bearing of the third embodiment, and the lower view is a view showing a cross section in the axial direction of the half bearing of the third embodiment. 上図は、従来技術の半割軸受の摺動層表面から見た図であり、下図は、従来技術の半割軸受の軸線方向の断面を示す図である。The upper view is a view seen from the surface of the sliding layer of the prior art half bearing, and the lower view is a view showing a cross section in the axial direction of the prior art half bearing. 従来技術の軸受保持穴の変形時の隙間を示す図である。。It is a figure which shows the clearance gap at the time of a deformation | transformation of the bearing holding hole of a prior art. . 従来技術の半割軸受を用いた場合において、（Ａ）は、隙間にエンジンオイル及び生成物が吸引される状態を示す模式図であり、（Ｂ）は、隙間内をエンジンオイル及び生成物が移動する状態を示す模式図であり、（Ｃ）は、エンジンオイル及び生成物が堆積された状態を示す模式図である。In the case of using a conventional half bearing, (A) is a schematic view showing a state in which engine oil and product are sucked into the gap, and (B) is a view in which engine oil and product are placed in the gap. It is a schematic diagram which shows the state which moves, (C) is a schematic diagram which shows the state in which engine oil and the product were deposited.

以下、本発明の実施例について、図面を参照しながら説明する。   Embodiments of the present invention will be described below with reference to the drawings.

（軸受装置の全体構成）
図１には、二つの軸受装置を含む構造体１が示されている。即ち、構造体１は、ジャーナル部６とクランクピン部５と図示されないクランクアーム部とを備えるクランク軸を有し、ジャーナル部６と軸受ハウジング（主軸受ハウジング）７と軸受保持穴７５に装着される主軸受４とから成る一つ目の軸受装置と、クランクピン部５と軸受ハウジング（コンロッド軸受ハウジング）２１と軸受保持穴２６に装着されるコンロッド軸受３とから成る二つ目の軸受装置と、を含む。 (Overall configuration of bearing device)
FIG. 1 shows a structure 1 including two bearing devices. That is, the structure 1 has a crankshaft including a journal portion 6, a crankpin portion 5, and a crank arm portion (not shown), and is attached to the journal portion 6, the bearing housing (main bearing housing) 7, and the bearing holding hole 75. A first bearing device comprising a main bearing 4, a second bearing device comprising a crank pin portion 5, a bearing housing (a connecting rod bearing housing) 21, and a connecting rod bearing 3 mounted in a bearing holding hole 26; ,including.

クランク軸におけるジャーナル部６とクランクピン部５とは、それぞれ主軸受４とコンロッド軸受３に回転自在に支持される。   The journal portion 6 and the crankpin portion 5 in the crankshaft are rotatably supported by the main bearing 4 and the connecting rod bearing 3, respectively.

主軸受４に対しては、オイルポンプによって吐出された潤滑油が、シリンダブロック７１の壁内に形成されたオイルギャラリーから主軸受４の壁に形成された貫通口を通じて、主軸受の内周面に沿って形成された潤滑油溝４１ａ内に送り込まれる。また、ジャーナル部６の直径方向には第１潤滑油路６ａが貫通形成され、この第１潤滑油路６ａの両端開口が主軸受４の潤滑油溝４１ａと連通するようになっている。さらに、ジャーナル部６の第１潤滑油路６ａから、クランクアーム部を通る第２潤滑油路５ａが分岐して形成され、この第２潤滑油路５ａが、クランクピン部５の直径方向に貫通形成された第３潤滑油路５ｂに連通している。このようにして、シリンダブロック７１の壁内のオイルギャラリーから貫通口を通じて主軸受４の内周面に形成された潤滑油溝４１ａ内に送り込まれた潤滑油は、第１潤滑油路６ａ、第２潤滑油路５ａ及び第３潤滑油路５ｂを経て、第３潤滑油路５ｂの末端に開口した吐出口から、クランクピン部５とコンロッド軸受ハウジング２１の軸受保持穴２６に保持されたコンロッド軸受３の摺動面間に供給される   For the main bearing 4, the lubricating oil discharged by the oil pump passes through the through hole formed in the wall of the main bearing 4 from the oil gallery formed in the wall of the cylinder block 71. Are fed into the lubricating oil groove 41a formed along Further, a first lubricating oil passage 6 a is formed through in the diameter direction of the journal portion 6, and both end openings of the first lubricating oil passage 6 a communicate with the lubricating oil groove 41 a of the main bearing 4. Further, a second lubricating oil passage 5 a that passes through the crank arm portion is branched from the first lubricating oil passage 6 a of the journal portion 6, and the second lubricating oil passage 5 a penetrates in the diameter direction of the crank pin portion 5. It communicates with the formed third lubricating oil passage 5b. Thus, the lubricating oil fed from the oil gallery in the wall of the cylinder block 71 into the lubricating oil groove 41a formed on the inner peripheral surface of the main bearing 4 through the through-hole is the first lubricating oil passage 6a, The connecting rod bearing held in the bearing holding hole 26 of the crank pin portion 5 and the connecting rod bearing housing 21 from the discharge port opened at the end of the third lubricating oil passage 5b through the second lubricating oil passage 5a and the third lubricating oil passage 5b. Supplied between three sliding surfaces

軸受ハウジング（主軸受ハウジング）７は、半円筒面７３を有する第１の分割体（主軸受ブロック側ハウジング）７１と、半円筒面７４を有する第２の分割体（主軸受キャップ側ハウジング）７２と、から成り、軸受ハウジング（コンロッド軸受ハウジング）２１は、半円筒面２４を有する第１の分割体（コンロッド大端部側ハウジング）２２と、半円筒面２５を有する第２の分割体（コンロッドキャップ側ハウジング）２３と、から成る。また、軸受保持穴７５は、一対の半円筒面７３、７４が組み合されることで円筒形状に形成されると共に、半円筒面７３、７４がそれぞれ軸受保持穴７５の軸線方向に平行になされる。同様に、軸受保持穴２６は、一対の半円筒面２４、２５が組み合されることで円筒形状に形成されると共に、半円筒面２４、２５がそれぞれ軸受保持穴２６の軸線方向に平行になされる。   The bearing housing (main bearing housing) 7 includes a first divided body (main bearing block side housing) 71 having a semicylindrical surface 73 and a second divided body (main bearing cap side housing) 72 having a semicylindrical surface 74. The bearing housing (connecting rod bearing housing) 21 includes a first divided body (connecting rod large end side housing) 22 having a semi-cylindrical surface 24 and a second divided body (connecting rod) having a semi-cylindrical surface 25. Cap-side housing) 23. The bearing holding hole 75 is formed in a cylindrical shape by combining the pair of semi-cylindrical surfaces 73 and 74, and the semi-cylindrical surfaces 73 and 74 are respectively parallel to the axial direction of the bearing holding hole 75. Similarly, the bearing holding hole 26 is formed in a cylindrical shape by combining a pair of semi-cylindrical surfaces 24 and 25, and the semi-cylindrical surfaces 24 and 25 are respectively parallel to the axial direction of the bearing holding hole 26. .

主軸受４は、半割軸受４１、４２が一対となり形成され、それら一対の半割軸受４１、４２が一対の半円筒面７３、７４に装着され、軸受保持穴７５に保持される。同様に、コンロッド軸受３は、半割軸受３１、３２が一対となり形成され、それら一対の半割軸受３１、３２が一対の半円筒面２４、２５に装着され、軸受保持穴２６に保持される。   The main bearing 4 is formed of a pair of half bearings 41, 42. The pair of half bearings 41, 42 are mounted on a pair of semicylindrical surfaces 73, 74 and are held in a bearing holding hole 75. Similarly, the connecting rod bearing 3 is formed with a pair of half bearings 31, 32. The pair of half bearings 31, 32 are mounted on the pair of semicylindrical surfaces 24, 25 and held in the bearing holding hole 26. .

図２に示すように、半割軸受４１、４２及び３１、３２は、裏金層８１と摺動層９１とから成り、裏金層表面８２と摺動層表面９２をそれぞれ備える。裏金層８１は０．０５〜０．３５％の炭素を含む合金鋼等からなり、摺動層９１は、ホワイト合金（錫合金）、アルミニウム合金、銅合金等の軸受合金からなる。なお、摺動層表面９２には、電気めっき、真空蒸着、吹き付け等の手段を以って、更に鉛系、錫系、アルミニウム合金、合成樹脂等の表面層（オーバレイ層）が皮膜されることもある。   As shown in FIG. 2, the half bearings 41, 42, 31, and 32 include a back metal layer 81 and a sliding layer 91, and each include a back metal layer surface 82 and a sliding layer surface 92. The back metal layer 81 is made of an alloy steel containing 0.05 to 0.35% carbon, and the sliding layer 91 is made of a bearing alloy such as a white alloy (tin alloy), an aluminum alloy, or a copper alloy. The sliding layer surface 92 is further coated with a surface layer (overlay layer) of lead-based, tin-based, aluminum alloy, synthetic resin or the like by means of electroplating, vacuum deposition, spraying, or the like. There is also.

（軸受装置の詳細な構成）
以下、本発明の詳細な構成及び作用効果について、クランクピン部５と軸受ハウジング（コンロッド軸受ハウジング）２１と軸受保持穴２６に装着されるコンロッド軸受３とから成る二つ目の軸受装置を例として説明するが、ジャーナル部６と軸受ハウジング（主軸受ハウジング）７と軸受保持穴７５に装着される主軸受４とから成る一つ目の軸受装置に置き換えても同様の効果を奏する。 (Detailed configuration of bearing device)
Hereinafter, with respect to the detailed configuration and operational effects of the present invention, a second bearing device including the crank pin portion 5, the bearing housing (connecting rod bearing housing) 21, and the connecting rod bearing 3 mounted in the bearing holding hole 26 is taken as an example. Although described, the same effect can be obtained by replacing the first bearing device including the journal portion 6, the bearing housing (main bearing housing) 7, and the main bearing 4 mounted in the bearing holding hole 75.

図１に示されるコンロッド軸受３は、図３に示す半円筒形状を有する半割軸受３１、３２が一対となり形成される。ここで、図３の上図は、半割軸受３１、３２の摺動層表面９２側から見た図を示し、図３の下図は、半割軸受３１、３２の側面側から見た図を示している。半割軸受３１、３２は、それぞれ裏金層８１及び摺動層９１を有し、裏金層８１は、半割軸受３１、３２の径方向外側に裏金層表面８２を形成すると共に、摺動層９１は、半割軸受３１、３２の径方向内側に摺動層表面９２を形成する。   The connecting rod bearing 3 shown in FIG. 1 is formed by a pair of half bearings 31 and 32 having a semi-cylindrical shape shown in FIG. Here, the upper view of FIG. 3 shows a view seen from the sliding layer surface 92 side of the half bearings 31, 32, and the lower view of FIG. 3 shows a view seen from the side surface side of the half bearings 31, 32. Show. The half bearings 31 and 32 have a back metal layer 81 and a sliding layer 91, respectively. The back metal layer 81 forms a back metal layer surface 82 on the radially outer side of the half bearings 31 and 32, and the sliding layer 91. Forms the sliding layer surface 92 on the radially inner side of the half bearings 31, 32.

図４（Ａ）は、本発明における半割軸受３１、３２の詳細な構造を示している。図４（Ａ）の上図は、半割軸受３１、３２の摺動層表面９２側から見た図を示し、図４（Ａ）の下図は、図３に示す半割軸受３１、３２の周方向端面１００から４５°の位置の断面図を示している。図４（Ａ）に示すように、半割軸受３１、３２は、軸受壁厚Ｔ１が半割軸受３１、３２の軸線方向に亘って一定となるように形成される。また、図４（Ａ）に示すように、半割軸受３１、３２の裏金層表面８２は、軸受保持穴２６の半円筒面２４、２５に非装着状態にて、裏金層表面８２における半割軸受３１、３２の軸線方向両端部を結ぶ仮想線Ｍから径方向の外側（即ち、半割軸受３１、３２の裏金層８１側（径方向外側））に向かって凸状曲面が、半割軸受３１、３２の周方向全長に亘って形成されている。また、凸状曲面の頂部は、半割軸受３１、３２の軸線方向の中央部に位置する。なお、図４（Ａ）の下図に示される断面は、前述の通り、図３に示す半割軸受３１、３２の周方向端面１００から４５°の位置の断面として示されるが、断面の形状は、半割軸受３１、３２の周方向全長に亘って同じである。   FIG. 4A shows the detailed structure of the half bearings 31 and 32 in the present invention. 4A shows a view of the half bearings 31 and 32 viewed from the sliding layer surface 92 side, and the lower view of FIG. 4A shows the half bearings 31 and 32 shown in FIG. Sectional drawing of the position of 45 degrees from the circumferential direction end surface 100 is shown. As shown in FIG. 4A, the half bearings 31 and 32 are formed so that the bearing wall thickness T1 is constant over the axial direction of the half bearings 31 and 32. As shown in FIG. 4A, the back metal layer surface 82 of the half bearings 31 and 32 is not attached to the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26, and the half metal on the back metal layer surface 82 is attached. A convex curved surface is formed from the imaginary line M connecting both axial ends of the bearings 31 and 32 toward the outside in the radial direction (that is, the back metal layer 81 side (the outside in the radial direction) of the half bearings 31 and 32). 31 and 32 are formed over the entire length in the circumferential direction. Further, the top of the convex curved surface is located at the center in the axial direction of the half bearings 31 and 32. 4A is shown as a cross section at a position of 45 ° from the circumferential end face 100 of the half bearings 31 and 32 shown in FIG. 3 as described above. This is the same over the entire circumferential length of the half bearings 31 and 32.

図５（Ａ）に示すように、半割軸受３１、３２が軸受保持穴２６の半円筒面２４、２５に装着された状態では、組付応力により、半割軸受３１、３２の裏金層表面８２は、半円筒面２４、２５に密着されるように弾性変形され、軸受保持穴２６（半円筒面２４、２５）の軸線方向と平行となっている。   As shown in FIG. 5A, in the state where the half bearings 31 and 32 are mounted on the half cylindrical surfaces 24 and 25 of the bearing holding hole 26, the surface of the back metal layer of the half bearings 31 and 32 due to the assembly stress. 82 is elastically deformed so as to be in close contact with the semi-cylindrical surfaces 24 and 25, and is parallel to the axial direction of the bearing holding hole 26 (the semi-cylindrical surfaces 24 and 25).

なお、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６（半円筒面２４、２５）が軸線方向で平行関係にあることを確認する手段の一つとしては、一般的にアタリ検査と呼ばれる手法を用いることができる。即ち、半割軸受３１、３２を装着前の半円筒面２４、２５に塗料（一般的にブルーペーストと呼ばれる青色の塗料）を塗布した上で、半割軸受３１、３２を半円筒面２４、２５に装着し、規定の締結トルクで組付する。この工程によって、半割軸受３１、３２の裏金層表面８２には、半円筒面２４、２５との密着部分に塗料が転写される。その後、半割軸受３１、３２を取り出し、半割軸受３１、３２の裏金層表面８２に転写された塗料を更に転写用紙や転写フィルムに転写させる。ここで、半割軸受３１、３２の軸線方向の中央から端部に亘る範囲まで、転写用紙や転写フィルムに塗料が同様に転写されていれば、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６（半円筒面２４、２５）は、半割軸受３１、３２が装着された状態で密着関係にあり、即ち平行な関係にあることを確認することができる。   As one means for confirming that the back metal layer surface 82 of the half bearings 31 and 32 and the bearing holding hole 26 (semi-cylindrical surfaces 24 and 25) are parallel to each other in the axial direction, generally an atari inspection is performed. Can be used. That is, after applying paint (blue paint generally called blue paste) to the semi-cylindrical surfaces 24 and 25 before mounting the half bearings 31 and 32, the half bearings 31 and 32 are attached to the semi-cylindrical surfaces 24 and 25, respectively. Attach to 25 and assemble with the specified fastening torque. By this process, the coating material is transferred to the back metal layer surfaces 82 of the half bearings 31 and 32 at the close contact portions with the semicylindrical surfaces 24 and 25. Thereafter, the half bearings 31 and 32 are taken out, and the paint transferred to the back metal layer surface 82 of the half bearings 31 and 32 is further transferred onto a transfer sheet or a transfer film. Here, if the paint is similarly transferred to the transfer paper or transfer film from the center to the end of the half bearings 31 and 32 in the axial direction, the back metal layer surface 82 of the half bearings 31 and 32 and It can be confirmed that the bearing holding holes 26 (half-cylindrical surfaces 24, 25) are in a close contact relationship with the half bearings 31, 32 being mounted, that is, in a parallel relationship.

半割軸受３１、３２が装着される軸受保持穴２６の半円筒面２４、２５には、内燃機関運転時の動荷重による変形が発生する。運転に伴う動荷重が小さい間には、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５は、組付応力による密着力により密着された関係が保たれた状態にある。しかし、動荷重が大きくなると、軸受保持穴２６の半円筒面２４、２５の変形量が増大し、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５との密着力が低下する。   Deformation due to a dynamic load during operation of the internal combustion engine occurs on the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 to which the half bearings 31 and 32 are mounted. While the dynamic load associated with the operation is small, the back metal layer surface 82 of the half bearings 31 and 32 and the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 are kept in close contact with each other due to the adhesion due to the assembly stress. It is in the state. However, when the dynamic load increases, the deformation amount of the semicylindrical surfaces 24 and 25 of the bearing holding hole 26 increases, and the back metal layer surface 82 of the half bearings 31 and 32 and the semicylindrical surfaces 24 and 25 of the bearing holding hole 26. The adhesive strength of is reduced.

軸受保持穴２６の半円筒面２４、２５の変形量が大きくなると、半割軸受３１、３２の裏金層表面８２は、部分的に軸受保持穴２６の半円筒面２４、２５の変形に追従できなくなり、軸受保持穴２６の半円筒面２４、２５との密着の関係が部分的に失われる。即ち、組付応力により、軸受保持穴２６の半円筒面２４、２５と軸線方向で平行関係になるように弾性変形されていた半割軸受３１、３２の裏金層表面８２が、密着力低下により非装着時の形状（即ち、図４（Ａ）に示される半割軸受３１、３２の状態）に復元され、図５（Ｂ）に示すように、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５の端部側との間に隙間１１０が生成される。この際、発生した隙間１１０は、周囲の雰囲気よりも低圧であるため、図６（Ａ）に示すように、隙間１１０周辺のエンジンオイル１１１及び生成物１１２は、隙間１１０に吸引される。   When the deformation amount of the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 increases, the back metal layer surface 82 of the half bearings 31 and 32 can partially follow the deformation of the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26. The contact relationship with the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 is partially lost. That is, the back metal layer surface 82 of the half bearings 31 and 32 that has been elastically deformed so as to be in a parallel relationship in the axial direction with the semicylindrical surfaces 24 and 25 of the bearing holding hole 26 due to the assembly stress is reduced due to a decrease in adhesion. The shape is restored to the non-mounted shape (that is, the state of the half bearings 31, 32 shown in FIG. 4A), and as shown in FIG. 5B, the back metal layer surface 82 of the half bearings 31, 32 is obtained. And a gap 110 is generated between the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26. At this time, since the generated gap 110 has a lower pressure than the surrounding atmosphere, the engine oil 111 and the product 112 around the gap 110 are sucked into the gap 110 as shown in FIG.

隙間１１０が生成された後、軸受保持穴２６の半円筒面２４、２５に働く動荷重が減少することにより、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５の密着が復元されるが、本実施形態の半割軸受３１、３２は、半割軸受３１、３２の裏金層８１側（径方向外側）に向かって凸状曲面に形成されているため、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５の密着は、半割軸受３１、３２及び軸受保持穴２６の半円筒面２４、２５の軸線方向中央側から復元されることになる。   After the gap 110 is generated, the dynamic load acting on the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 is reduced, whereby the back metal layer surface 82 of the half bearings 31 and 32 and the semi-cylindrical surface 24 of the bearing holding hole 26. , 25 is restored, but the half bearings 31, 32 of the present embodiment are formed in a convex curved surface toward the back metal layer 81 side (radially outside) of the half bearings 31, 32. The close contact between the back metal layer surface 82 of the half bearings 31 and 32 and the semicylindrical surfaces 24 and 25 of the bearing holding hole 26 is the center of the half cylindrical surfaces 24 and 25 of the half bearings 31 and 32 and the bearing holding hole 26 in the axial direction. Will be restored from the side.

上記により、隙間１１０内のエンジンオイル１１１及び生成物１１２には、図６（Ｂ）に示すように、半割軸受３１、３２及び軸受保持穴２６の半円筒面２４、２５の軸線方向端部側に向かう圧力Ｆ１が働くこととなり、隙間１１０からエンジンオイル１１１及び生成物１１２が良好に排出され、図６（Ｃ）に示される密着が完全に復元した状態において、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５の間にエンジンオイル１１１及び生成物１１２が堆積されにくく、好適に半割軸受３１、３２の損傷を防止することができる。   Due to the above, the engine oil 111 and the product 112 in the gap 110 are subjected to axial ends of the half cylindrical surfaces 24 and 25 of the half bearings 31 and 32 and the bearing holding hole 26 as shown in FIG. In the state where the engine oil 111 and the product 112 are discharged well from the gap 110 and the close contact shown in FIG. 6C is completely restored, the pressure F1 toward the side is exerted. The engine oil 111 and the product 112 are not easily deposited between the back metal layer surface 82 and the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26, and damage to the half bearings 31 and 32 can be preferably prevented.

なお、半割軸受３１、３２では、一般的に軸線方向中央部が最も高い負荷を受ける。本実施形態では、凸状曲面の頂部が半割軸受３１、３２の軸線方向の中央部に位置されていることにより、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５の密着は、軸線方向中央部で最も維持されやすく、同部はエンジンオイル１１１及び生成物１１２が吸入される可能性が最も低い。即ち、同部にエンジンオイル１１１及び生成物１１２が堆積されにくく、好適に半割軸受３１、３２の損傷を防止することができる。   In the half bearings 31 and 32, the central portion in the axial direction generally receives the highest load. In the present embodiment, the top of the convex curved surface is positioned at the center in the axial direction of the half bearings 31 and 32, so that the back metal layer surface 82 of the half bearings 31 and 32 and the half cylinder of the bearing holding hole 26. The close contact between the surfaces 24 and 25 is most easily maintained at the central portion in the axial direction, and the portion is least likely to receive the engine oil 111 and the product 112. That is, the engine oil 111 and the product 112 are not easily deposited on the same portion, and the half bearings 31 and 32 can be suitably prevented from being damaged.

また、隙間１１０内のエンジンオイル１１１及び生成物１１２に対し、半割軸受３１、３２及び軸受保持穴２６の半円筒面２４、２５の軸線方向端部側に向かう圧力Ｆ１を働かせるために、凸状曲面の高さＨは、最小でも０．００１ｍｍ以上与えられることが望ましい。また、凸状曲面の高さＨが大きくなると、エンジンオイル１１１及び生成物１１２に働く圧力Ｆ１は大きくなるが、背反として、半割軸受３１、３２の軸線方向端部が、クランクピン部５側に近づくことになり、クランクピン部５側との接触の機会が増大することから、凸状曲面の高さＨは、最大で０．１ｍｍ以下に抑えることが望ましい。なお、凸状曲面の高さＨとは、図４（Ａ）の下図に示すように、裏金層表面８２における半割軸受３１、３２の軸線方向両端部を結ぶ仮想線Ｍから、凸状曲面の頂部までの高さとして表される。ここで、半割軸受３１、３２の外周面には、軸線方向両端の角縁部に面取を施すことも出来るが、このような面取を施す場合には、面取の表面は、本発明の「裏金層表面」には含まれない。   Further, a convex F1 is applied to the engine oil 111 and the product 112 in the gap 110 in order to apply the pressure F1 toward the axial ends of the half cylindrical surfaces 24 and 25 of the half bearings 31 and 32 and the bearing holding hole 26. It is desirable that the height H of the curved surface is at least 0.001 mm. Further, as the height H of the convex curved surface increases, the pressure F1 acting on the engine oil 111 and the product 112 increases, but as a contradiction, the axial ends of the half bearings 31 and 32 are on the crankpin 5 side. Therefore, the height of the convex curved surface is desirably suppressed to 0.1 mm or less at the maximum. The height H of the convex curved surface refers to a convex curved surface from an imaginary line M connecting the axial ends of the half bearings 31 and 32 on the back metal layer surface 82 as shown in the lower diagram of FIG. Expressed as the height to the top of Here, the outer peripheral surfaces of the half bearings 31 and 32 can be chamfered at the corner edges at both ends in the axial direction. It is not included in the “back metal layer surface” of the invention.

更に、本発明の半割軸受３１、３２は、軸受壁厚が該半割軸受の軸線方向に亘って一定であるため、該半割軸受３１、３２の摺動層表面９２に入力されるクランクピン部５の荷重を摺動層表面９２の広い範囲に分散させる（面圧を低く抑える）ことができるため、半割軸受３１、３２への負荷が減少され、好適に半割軸受３１、３２の損傷を防止することができる。   Further, since the bearing wall thickness of the half bearings 31 and 32 of the present invention is constant over the axial direction of the half bearing, the crank input to the sliding layer surface 92 of the half bearings 31 and 32 is provided. Since the load of the pin portion 5 can be distributed over a wide range of the sliding layer surface 92 (the surface pressure is kept low), the load on the half bearings 31 and 32 is reduced, and the half bearings 31 and 32 are preferably used. Can prevent damage.

（従来技術の詳細な構成）
次に、本発明の実施例と対比させて、従来技術の詳細な構成について説明する。なお、軸受装置の全体構成は、本発明の実施例と同様であることから、説明を省略する。 (Detailed configuration of conventional technology)
Next, the detailed configuration of the prior art will be described in comparison with the embodiment of the present invention. The overall configuration of the bearing device is the same as that of the embodiment of the present invention, and thus the description thereof is omitted.

従来技術のコンロッド軸受は、図３に示す本発明の半割軸受３１、３２と同様に、半円筒形状を持つ半割軸受１３１、１３２が一対となり形成される。また、従来技術の半割軸受１３１、１３２は、本発明の半割軸受３１、３２と同様に、それぞれ裏金層及び摺動層を有し、裏金層は半割軸受１３１、１３２の径方向外側に裏金層表面１８２を形成すると共に、摺動層は、半割軸受１３１、１３２の径方向内側に摺動層表面１９２を形成する。   As in the case of the half bearings 31 and 32 of the present invention shown in FIG. 3, the conventional connecting rod bearing is formed by a pair of half bearings 131 and 132 having a semi-cylindrical shape. Similarly to the half bearings 31 and 32 of the present invention, the half bearings 131 and 132 of the prior art have a back metal layer and a sliding layer, respectively, and the back metal layer is radially outside the half bearings 131 and 132. And the sliding layer forms the sliding layer surface 192 on the inner side in the radial direction of the half bearings 131 and 132.

図９に示すように、半割軸受１３１、１３２には、軸受壁厚Ｔ１が半割軸受１３１、１３２の軸線方向に亘って一定となるように形成される。ここで、図９の上図は、半割軸受１３１、１３２の摺動層表面１９２側から見た図を示し、図９の下図は、半割軸受１３１、１３２の周方向端面から４５°の位置の断面図を示している。また、図９に示すように、半割軸受１３１、１３２の裏金層表面１８２には、軸受保持穴の半円筒面１２４、１２５に非装着状態にて、半割軸受１３１、１３２の軸線方向に、半割軸受１３１、１３２の摺動層側（径方向内側）に向かって凹状曲面が形成されている。また、凹状曲面の頂部は、半割軸受１３１、１３２の軸線方向の中央部に位置する。なお、図９の下図に示される断面は、前述の通り、半割軸受１３１、１３２の周方向端面から４５°の位置の断面として示されるが、断面の形状は、半割軸受１３１、１３２の周方向全長に亘って同じである。   As shown in FIG. 9, the half bearings 131 and 132 are formed such that the bearing wall thickness T <b> 1 is constant over the axial direction of the half bearings 131 and 132. Here, the upper diagram in FIG. 9 shows a view seen from the sliding layer surface 192 side of the half bearings 131 and 132, and the lower diagram in FIG. 9 is 45 ° from the circumferential end surface of the half bearings 131 and 132. A sectional view of the position is shown. Further, as shown in FIG. 9, the back metal layer surfaces 182 of the half bearings 131 and 132 are not attached to the half cylindrical surfaces 124 and 125 of the bearing holding holes in the axial direction of the half bearings 131 and 132. A concave curved surface is formed toward the sliding layer side (radially inner side) of the half bearings 131 and 132. Further, the top of the concave curved surface is located at the center of the half bearings 131 and 132 in the axial direction. 9 is shown as a cross section at a position of 45 ° from the circumferential end surface of the half bearings 131 and 132, as described above, the shape of the cross section is that of the half bearings 131 and 132. It is the same over the entire length in the circumferential direction.

図５に示す本発明の半割軸受３１、３２と同様に、半割軸受１３１、１３２が軸受保持穴の半円筒面１２４、１２５に装着された状態では、組付応力により、半割軸受１３１、１３２の裏金層表面１８２は、半円筒面１２４、１２５に密着されるように弾性変形され、軸受保持穴（半円筒面１２４、１２５）の軸線方向と平行となっている。   Similarly to the half bearings 31 and 32 of the present invention shown in FIG. 5, when the half bearings 131 and 132 are mounted on the half cylindrical surfaces 124 and 125 of the bearing holding holes, the half bearing 131 is caused by the assembly stress. 132 are elastically deformed so as to be in close contact with the semi-cylindrical surfaces 124 and 125, and are parallel to the axial direction of the bearing holding holes (semi-cylindrical surfaces 124 and 125).

半割軸受１３１、１３２が装着される軸受保持穴の半円筒面１２４、１２５には、内燃機関運転時の動荷重による変形が発生する。運転に伴う動荷重が小さい間には、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５は、組付応力による密着力により密着された関係が保たれた状態にある。しかし、動荷重が大きくなると、軸受保持穴の半円筒面１２４、１２５の変形量が増大し、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５のとの密着力が低下する。   Deformation due to a dynamic load during operation of the internal combustion engine occurs on the semi-cylindrical surfaces 124 and 125 of the bearing holding holes in which the half bearings 131 and 132 are mounted. While the dynamic load accompanying the operation was small, the relationship between the back metal layer surface 182 of the half bearings 131 and 132 and the semi-cylindrical surfaces 124 and 125 of the bearing holding holes was kept in close contact due to the adhesion due to the assembly stress. Is in a state. However, when the dynamic load increases, the deformation amount of the semi-cylindrical surfaces 124 and 125 of the bearing holding hole increases, and the back metal layer surface 182 of the half bearings 131 and 132 and the semi-cylindrical surfaces 124 and 125 of the bearing holding hole increase. The adhesion is reduced.

軸受保持穴の半円筒面１２４、１２５の変形量が大きくなると、半割軸受１３１、１３２の裏金層表面１８２は、部分的に軸受保持穴の半円筒面１２４、１２５の変形に追従できなくなり、軸受保持穴の半円筒面１２４、１２５との密着の関係が部分的に失われる。即ち、組付応力により、軸受保持穴の半円筒面１２４、１２５と軸線方向で平行関係になるように弾性変形されていた半割軸受１３１、１３２の裏金層表面１８２が、密着力低下により非装着時の形状（即ち、図９に示される半割軸受１３１、１３２の状態）に復元され、図１０に示すように、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５の中央側との間に隙間２１０が生成される。この際、発生した隙間２１０は、周囲の雰囲気よりも低圧であるため、図１１（Ａ）に示すように、隙間２１０周辺のエンジンオイル２１１及び生成物２１２は、隙間２１０に吸引される。   When the deformation amount of the semi-cylindrical surfaces 124 and 125 of the bearing holding hole increases, the back metal layer surface 182 of the half bearings 131 and 132 cannot partially follow the deformation of the semi-cylindrical surfaces 124 and 125 of the bearing holding hole. The close contact relationship with the semi-cylindrical surfaces 124 and 125 of the bearing holding hole is partially lost. That is, the back metal layer surfaces 182 of the half bearings 131 and 132 that have been elastically deformed so as to have a parallel relationship in the axial direction with the semi-cylindrical surfaces 124 and 125 of the bearing holding hole due to the assembly stress are not The shape at the time of mounting (that is, the state of the half bearings 131 and 132 shown in FIG. 9) is restored, and as shown in FIG. 10, the back metal layer surface 182 of the half bearings 131 and 132 and the half cylinder of the bearing holding hole. A gap 210 is generated between the surfaces 124 and 125 and the center side. At this time, since the generated gap 210 has a lower pressure than the surrounding atmosphere, the engine oil 211 and the product 212 around the gap 210 are sucked into the gap 210 as shown in FIG.

隙間２１０が生成された後、軸受保持穴の半円筒面１２４、１２５に働く動荷重が減少することにより、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５の密着が復元されるが、従来技術の半割軸受１３１、１３２は、半割軸受１３１、１３２の摺動層９１側（径方向内側）に向かって凹状曲面に形成されているため、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５の密着は、半割軸受１３１、１３２及び軸受保持穴の半円筒面１２４、１２５の軸線方向端部側から復元されることになる。   After the gap 210 is generated, the dynamic load acting on the semi-cylindrical surfaces 124 and 125 of the bearing holding holes is reduced, so that the back metal layer surface 182 of the half bearings 131 and 132 and the semi-cylindrical surfaces 124 and 125 of the bearing holding holes. However, since the half bearings 131 and 132 of the prior art are formed in a concave curved surface toward the sliding layer 91 side (radially inner side) of the half bearings 131 and 132, the half bearing The adhesion between the back metal layer surface 182 of the bearings 131 and 132 and the semi-cylindrical surfaces 124 and 125 of the bearing holding hole is restored from the axial end portions of the half bearings 131 and 132 and the semi-cylindrical surfaces 124 and 125 of the bearing holding hole. Will be.

上記により、隙間２１０内のエンジンオイル２１１及び生成物２１２には、図１１（Ｂ）に示すように、半割軸受１３１、１３２及び軸受保持穴の半円筒面１２４、１２５の軸線方向中央側に向かう圧力Ｆ２が働くこととなり、隙間２１０からエンジンオイル２１１及び生成物２１２が排出されにくく、図１１（Ｃ）に示される密着が復元した状態において、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５の間にエンジンオイル２１１及び生成物２１２が堆積される。そして、堆積されたエンジンオイル２１１及び生成物２１２は、半割軸受１３１、１３２の裏金層表面１８２を押し上げるため、堆積されたエンジンオイル２１１及び生成物２１２の径方向内側に位置する半割軸受１３１、１３２の摺動層表面１９２が部分的に***される。このため、***された摺動層表面１９２は、クランクピン部との直接接触の機会を増大させ、接触抵抗による発熱が増大し、最悪の場合には焼付き損傷に至る。   As described above, the engine oil 211 and the product 212 in the gap 210 are placed on the center side in the axial direction of the half cylindrical surfaces 124 and 125 of the half bearings 131 and 132 and the bearing holding holes as shown in FIG. In the state where the engine oil 211 and the product 212 are not easily discharged from the gap 210 and the close contact shown in FIG. 11C is restored, the back metal layer surfaces 182 of the half bearings 131 and 132 are Engine oil 211 and product 212 are deposited between the semi-cylindrical surfaces 124, 125 of the bearing retaining holes. The accumulated engine oil 211 and the product 212 push up the back metal layer surface 182 of the half bearings 131 and 132, so that the half bearing 131 is located on the radially inner side of the accumulated engine oil 211 and the product 212. 132 are partially raised. For this reason, the raised sliding layer surface 192 increases the chance of direct contact with the crankpin portion, and heat generation due to contact resistance increases, and in the worst case, seizure damage occurs.

なお、半割軸受１３１、１３２では、一般的に軸線方向中央が最も高い負荷を受ける。従来技術では、凹状曲面の頂部が半割軸受１３１、１３２の軸線方向の中央部に位置されていることより、半割軸受１３１、１３２の裏金層表面１８２と軸受保持穴の半円筒面１２４、１２５の密着は、軸線方向中央で最も失われやすく、同部はエンジンオイル２１１及び生成物２１２が吸入される可能性が最も高い。即ち、同部にエンジンオイル２１１及び生成物２１２が堆積されやすく、半割軸受の損傷１３１、１３２が発生しやすい。   In the half bearings 131 and 132, the center in the axial direction generally receives the highest load. In the prior art, the top of the concave curved surface is positioned at the center in the axial direction of the half bearings 131 and 132, so that the back metal layer surface 182 of the half bearings 131 and 132 and the half cylindrical surface 124 of the bearing holding hole, The adhesion of 125 is most easily lost at the center in the axial direction, and the engine oil 211 and the product 212 are most likely to be sucked into the same portion. That is, the engine oil 211 and the product 212 are easily deposited on the same portion, and the damages 131 and 132 of the half bearing are likely to occur.

従来技術の半割軸受１３１、１３２と対比して、本発明の半割軸受３１、３２は、軸受保持穴２６の半円筒面２４、２５に非装着状態にて、半割軸受３１、３２の裏金層８１側（径方向外側）に向かって凸状曲面に形成されているため、好適に半割軸受３１、３２の損傷を防止する作用を有することを理解することができる。   In contrast to the prior art half bearings 131 and 132, the half bearings 31 and 32 of the present invention are not attached to the half cylindrical surfaces 24 and 25 of the bearing holding hole 26. Since it is formed in a convex curved surface toward the back metal layer 81 side (radially outer side), it can be understood that it has an effect of suitably preventing the half bearings 31 and 32 from being damaged.

（半割軸受の加工方法）
次に、本発明の半割軸受３１、３２の加工方法の一つの例を、図７を参照して説明する。本発明の半割軸受３１、３２については、以下の工程１〜６の手順で作成する。 (Half bearing machining method)
Next, one example of the processing method of the half bearings 31 and 32 of the present invention will be described with reference to FIG. About the half bearings 31 and 32 of this invention, it creates in the procedure of the following processes 1-6.

まず、工程１では、摺動層９１と裏金層８１を有する合板（バイメタル）をプレス加工により短冊状の平板に成型する（図示せず）。そして、工程２では、図７（Ａ）に示すように、短冊状の平板の裏金層表面８２に、軸線方向に凹状曲面を有する凹状ローラ１３０を押し当て、裏金層表面８２に凸状曲面を形成すると共に、平板を半円筒形状（成形品）に加工する。その後、工程３では、図７（Ｂ）に示すように、成形品の凸状曲面に形成された裏金層表面８２側を冶具１４０の表面に設置する。この段階では、裏金層表面８２と冶具１４０の表面は完全に密着していない。   First, in step 1, a plywood (bimetal) having a sliding layer 91 and a back metal layer 81 is formed into a strip-shaped flat plate by pressing (not shown). Then, in step 2, as shown in FIG. 7A, a concave roller 130 having a concave curved surface in the axial direction is pressed against the back plate surface 82 of the strip-shaped flat plate, and the convex curved surface is formed on the back plate layer surface 82. At the same time, the flat plate is processed into a semi-cylindrical shape (molded product). Thereafter, in step 3, as shown in FIG. 7B, the back metal layer surface 82 side formed on the convex curved surface of the molded product is placed on the surface of the jig 140. At this stage, the back metal layer surface 82 and the surface of the jig 140 are not completely adhered.

次いで、工程４では、図７（Ｃ）に示すように、所定の締結トルクにより、成形品の裏金層表面８２と冶具１４０の表面を密着させる。この際、締結トルクにより成形品が変形し、裏金層表面８２の凸状曲面は、摺動層表面９２の凸状曲面に転換される。そして、工程５では、図７（Ｄ）に示すように、所定の締結トルクをかけた状態で、摺動層表面９２を、冶具１４０の表面の軸線方向に平行となるように除去加工する。その後、工程６では、図７（Ｅ）に示すように、締結トルクを除去することにより、成形品の壁厚が軸線方向に亘って一定であり、且つ、軸線方向に、裏金層８１側（径方向外側）に向かって凸状曲面を有する半割軸受３１、３２に成形される。   Next, in step 4, as shown in FIG. 7C, the back metal layer surface 82 of the molded product and the surface of the jig 140 are brought into close contact with each other with a predetermined fastening torque. At this time, the molded product is deformed by the fastening torque, and the convex curved surface of the back metal layer surface 82 is converted into the convex curved surface of the sliding layer surface 92. Then, in step 5, as shown in FIG. 7D, the sliding layer surface 92 is removed so as to be parallel to the axial direction of the surface of the jig 140 with a predetermined fastening torque applied. Thereafter, in step 6, as shown in FIG. 7E, by removing the fastening torque, the wall thickness of the molded product is constant over the axial direction, and the back metal layer 81 side ( The half bearings 31 and 32 having a convex curved surface are formed toward the radially outer side.

（別実施例）
次に、本発明における別実施形態として第２実施形態及び第３実施形態を示す。なお、上記した実施形態と構成及び作用が同様である部分については、説明を省略する。また、別実施形態においても、クランクピン部５と軸受ハウジング（コンロッド軸受ハウジング）２１と軸受保持穴２６に装着されるコンロッド軸受３とから成る二つ目の軸受装置に提供されるコンロッド軸受３を例として説明するが、ジャーナル部６と軸受ハウジング（主軸受ハウジング）７と軸受保持穴７５に装着される主軸受４とから成る一つ目の軸受装置に提供される主軸受４に置き換えても同様の効果を奏する。 (Another embodiment)
Next, 2nd Embodiment and 3rd Embodiment are shown as another embodiment in this invention. In addition, description is abbreviate | omitted about the part which is the same as that of above-mentioned embodiment and an effect | action. In another embodiment, the connecting rod bearing 3 provided in the second bearing device including the crankpin portion 5, the bearing housing (connecting rod bearing housing) 21, and the connecting rod bearing 3 mounted in the bearing holding hole 26 is provided. Although described as an example, the main bearing 4 provided in the first bearing device including the journal portion 6, the bearing housing (main bearing housing) 7, and the main bearing 4 mounted in the bearing holding hole 75 may be replaced. The same effect is produced.

まず、第２実施形態について、図４（Ｂ）を参照して説明する。図４（Ｂ）の上図は、半割軸受３１、３２の摺動層表面９２側から見た図を示し、図４（Ｂ）の下図は、図３に示す半割軸受３１、３２の周方向端面１００から４５°の位置の断面図を示している。図４（Ｂ）に示すように、コンロッド軸受３を構成する半割軸受３１、３２の少なくとも一方は、半割軸受３１、３２の軸線方向の中央部を含み形成される軸受壁厚Ｔ１が一定である平滑領域と、該平滑領域の軸線方向両側に形成される軸受壁厚Ｔ２が半割軸受３１、３２の軸線方向端部側に向かって小さくなる傾斜領域９３と、を有する。   First, the second embodiment will be described with reference to FIG. 4B shows a view of the half bearings 31 and 32 as viewed from the sliding layer surface 92 side, and the lower view of FIG. 4B shows the half bearings 31 and 32 shown in FIG. Sectional drawing of the position of 45 degrees from the circumferential direction end surface 100 is shown. As shown in FIG. 4 (B), at least one of the half bearings 31 and 32 constituting the connecting rod bearing 3 has a constant bearing wall thickness T1 formed including the central portion in the axial direction of the half bearings 31 and 32. And an inclined region 93 in which the bearing wall thickness T2 formed on both sides in the axial direction of the smooth region becomes smaller toward the end portions in the axial direction of the half bearings 31 and 32.

また、図４（Ｂ）に示すように、半割軸受３１、３２の少なくとも一方は、軸受保持穴２６の半円筒面２４、２５に非装着状態にて、裏金層表面８２が、半割軸受３１、３２の軸線方向に、半割軸受３１、３２の裏金層８１側（径方向外側）に向かって凸状曲面に形成されている。この凸状曲面は、半割軸受３１、３２の周方向全長に亘る範囲で施される。また、凸状曲面の頂部は、半割軸受３１、３２の軸線方向の中央部に位置する。   Further, as shown in FIG. 4B, at least one of the half bearings 31 and 32 is not attached to the half cylindrical surfaces 24 and 25 of the bearing holding hole 26, and the back metal layer surface 82 has a half bearing. In the axial direction of 31 and 32, it forms in a convex curved surface toward the back metal layer 81 side (radial direction outer side) of the half bearings 31 and 32. As shown in FIG. This convex curved surface is provided in a range extending over the entire circumferential length of the half bearings 31 and 32. Further, the top of the convex curved surface is located at the center in the axial direction of the half bearings 31 and 32.

軸受装置は、例えばクランク軸の剛性不足等の理由から、半割軸受３１、３２の軸線方向端部とクランクピン部５が接触しやすい。別実施形態では、半割軸受３１、３２の軸線方向両側に傾斜領域９３を有するため、半割軸受３１、３２とクランクピン部５の距離を離すことができ、接触回避により、好適に半割軸受３１、３２の損傷を防止することができる。   In the bearing device, for example, due to insufficient rigidity of the crankshaft, the axial ends of the half bearings 31 and 32 and the crankpin portion 5 are likely to contact each other. In another embodiment, since the inclined regions 93 are provided on both sides in the axial direction of the half bearings 31 and 32, the distance between the half bearings 31 and 32 and the crankpin portion 5 can be increased. Damage to the bearings 31 and 32 can be prevented.

また、第３実施形態について、図８を参照して説明する。図８の上図は、半割軸受３１、３２の摺動層表面９２側から見た図を示し、図８の下図は、半割軸受３１、３２の側面側から見た図を示している。図８に示すように、半割軸受３１、３２の裏金層表面８２は、軸受保持穴２６の半円筒面２４、２５に非装着状態にて、半割軸受３１、３２の周方向端面１００の両端面から周方向中央部側に向かうそれぞれ円周角度４５°の位置Ｐ１を基準として−５°〜＋５°の範囲Θ１において、凸状曲面を形成するようにしてもよい。ここで、Θ１以外の範囲における裏金層表面８２は、凸状曲面である必要はなく、従来技術における凹状曲面でもよく、平滑面でもよい。一般的に軸受ハウジング（コンロッド軸受ハウジング）２１は、半円筒面２４、２５の周方向両端部から４５°位置（即ち、半割軸受３１、３２の周方向端面１００から４５°位置Ｐ１の位置）において、剛性が低く、特に同部では軸受保持穴２６の半円筒面２４、２５の変形量が大きくなりやすいが、半割軸受３１、３２の周方向端面１００の両端面から周方向中央部側に向かうそれぞれ円周角度４５°の位置Ｐ１を基準として−５°〜＋５°の範囲Θ１に凸状曲面が形成されることで、軸受保持穴２６の半円筒部２４、２５の変形量が多い場合にも、半割軸受３１、３２の裏金層表面８２と軸受保持穴２６の半円筒面２４、２５との間の隙間にエンジンオイル１１１及び生成物１１２が堆積しにくい軸受装置を提供することができる。   The third embodiment will be described with reference to FIG. 8 shows a view of the half bearings 31 and 32 as seen from the sliding layer surface 92 side, and the lower view of FIG. 8 shows a view of the half bearings 31 and 32 as seen from the side. . As shown in FIG. 8, the back metal layer surfaces 82 of the half bearings 31 and 32 are not attached to the half cylindrical surfaces 24 and 25 of the bearing holding hole 26, and the circumferential end surfaces 100 of the half bearings 31 and 32 are not attached. A convex curved surface may be formed in a range Θ1 of −5 ° to + 5 ° with reference to a position P1 with a circumferential angle of 45 ° from the both end faces toward the center in the circumferential direction. Here, the back metal layer surface 82 in a range other than Θ1 does not need to be a convex curved surface, and may be a concave curved surface in the prior art or a smooth surface. Generally, the bearing housing (connecting rod bearing housing) 21 is positioned at 45 ° from both circumferential ends of the semi-cylindrical surfaces 24 and 25 (that is, at a position 45 ° from the circumferential end surface 100 of the half bearings 31 and 32). However, the amount of deformation of the semi-cylindrical surfaces 24 and 25 of the bearing holding hole 26 tends to be large at the same part, but the circumferential end side from the both end surfaces of the circumferential end surfaces 100 of the half bearings 31 and 32 Since the convex curved surface is formed in the range Θ1 of −5 ° to + 5 ° with respect to the position P1 having a circumferential angle of 45 ° toward each other, the deformation amount of the semi-cylindrical portions 24 and 25 of the bearing holding hole 26 is large. Even in such a case, a bearing device is provided in which engine oil 111 and product 112 are not easily deposited in the gap between the back metal layer surface 82 of the half bearings 31 and 32 and the semicylindrical surfaces 24 and 25 of the bearing holding hole 26. Can do.

１ 構造体
２ コンロッド
３ コンロッド軸受
４ 主軸受
５ クランクピン部
６ ジャーナル部
７ 軸受ハウジング（主軸受ハウジング）
２１ 軸受ハウジング（コンロッド軸受ハウジング）
２２ 第１の分割体（コンロッド大端部側ハウジング）
２３ 第２の分割体（コンロッドキャップ側ハウジング）
２４、２５ 半円筒面
２６ 軸受保持穴
３１、３２ 半割軸受
４１、４２ 半割軸受
７１ 第１の分割体（主軸受ブロック側ハウジング）
７２ 第２の分割体（主軸受キャップ側ハウジング）
７３、７４ 半円筒面
７５ 軸受保持穴
８１ 裏金層
８２ 裏金層表面
９１ 摺動層
９２ 摺動層表面 DESCRIPTION OF SYMBOLS 1 Structure 2 Connecting rod 3 Connecting rod bearing 4 Main bearing 5 Crank pin part 6 Journal part 7 Bearing housing (main bearing housing)
21 Bearing housing (Connecting rod bearing housing)
22 1st division body (connecting rod large end side housing)
23 Second divided body (connector cap side housing)
24, 25 Semi-cylindrical surface 26 Bearing holding hole 31, 32 Half bearing 41, 42 Half bearing 71 First divided body (main bearing block side housing)
72 Second divided body (main bearing cap side housing)
73, 74 Semi-cylindrical surface 75 Bearing holding hole 81 Back metal layer 82 Back metal layer surface 91 Sliding layer 92 Sliding layer surface

Claims (7)

内燃機関のクランク軸と、該クランク軸を回転自在に支持するすべり軸受と、該すべり軸受を保持する軸受保持穴を有する軸受ハウジングと、から成る軸受装置において、
前記すべり軸受は、各々が裏金層及び摺動層を有する一対の半割軸受から構成され、
前記軸受ハウジングは、各々が半円筒面を有する第１の分割体と第２の分割体とから構成され、
前記軸受保持穴は、一対の半円筒面が組み合わされることで円筒形状に形成されると共に、該半円筒面が前記軸受保持穴の軸線方向と平行になされ、
前記一対の半割軸受は、前記一対の半円筒面に装着され前記軸受保持穴に保持され、
前記軸受保持穴に非装着状態の半割軸受は、最小で、該半割軸受の周方向両端面から周方向中央部側に向かうそれぞれ円周角度４５°の位置Ｐ１を基準として−５°〜＋５°の円周角度の範囲、最大で、該半割軸受の周方向全長に亘る範囲において、前記裏金層表面が、該裏金層表面における前記半割軸受の軸線方向両端部を結ぶ仮想線Ｍから径方向の外側に向かう凸状曲面を有し、
前記軸受保持穴に前記一対の半割軸受が装着された状態では、前記裏金層表面が、前記軸受保持穴の軸線方向と平行となることを特徴とする軸受装置。 In a bearing device comprising a crankshaft of an internal combustion engine, a slide bearing that rotatably supports the crankshaft, and a bearing housing having a bearing holding hole that holds the slide bearing,
The plain bearing is composed of a pair of half bearings each having a back metal layer and a sliding layer,
The bearing housing is composed of a first divided body and a second divided body each having a semi-cylindrical surface;
The bearing holding hole is formed in a cylindrical shape by combining a pair of semi-cylindrical surfaces, and the semi-cylindrical surface is made parallel to the axial direction of the bearing holding hole,
The pair of half bearings are mounted on the pair of semi-cylindrical surfaces and held in the bearing holding holes,
The half bearings that are not mounted in the bearing holding holes are at least −5 ° to about the position P1 with a circumferential angle of 45 ° from the circumferential end surfaces of the half bearing toward the circumferential center. An imaginary line M connecting the surface of the back metal layer to both ends in the axial direction of the half bearing on the surface of the back metal layer in a range of a circumferential angle of + 5 °, and at the maximum, the range covering the entire circumferential length of the half bearing. Having a convex curved surface that extends radially outward from
In a state where the pair of half bearings are mounted in the bearing holding holes, the surface of the back metal layer is parallel to the axial direction of the bearing holding holes. 前記凸状曲面の頂部は、前記半割軸受の軸線方向の中央部に位置することを特徴とする請求項１記載の軸受装置。   The bearing device according to claim 1, wherein a top portion of the convex curved surface is located at a central portion in an axial direction of the half bearing. 前記凸状曲面の高さＨは、０．００１〜０．１ｍｍであることを特徴とする請求項１または請求項２記載の軸受装置。   The bearing device according to claim 1, wherein a height H of the convex curved surface is 0.001 to 0.1 mm. 前記半割軸受は、軸受壁厚が該半割軸受の軸線方向に亘って一定であることを特徴とする請求項１乃至請求項３のいずれに記載の軸受装置。   The bearing device according to any one of claims 1 to 3, wherein the half bearing has a constant bearing wall thickness along an axial direction of the half bearing. 前記半割軸受は、該半割軸受の軸線方向の中央部を含み形成され、軸受壁厚が一定である平滑領域と、該平滑領域の軸線方向両側に形成され、軸受壁厚が該半割軸受の軸線方向端部側に向かって小さくなる傾斜領域と、を有することを特徴とする請求項１乃至請求項３のいずれかに記載の軸受装置。   The half bearing is formed so as to include a central portion in the axial direction of the half bearing, and is formed on a smooth region having a constant bearing wall thickness and on both sides in the axial direction of the smooth region. The bearing device according to any one of claims 1 to 3, further comprising an inclined region that decreases toward an axial end portion of the bearing. 前記すべり軸受は、前記クランク軸のクランクピン部を支承するコンロッド軸受であることを特徴とする請求項１乃至請求項５のいずれかに記載の軸受装置。   The bearing device according to claim 1, wherein the slide bearing is a connecting rod bearing that supports a crankpin portion of the crankshaft. 前記すべり軸受は、前記クランク軸のジャーナル部を支承する主軸受であることを特徴とする請求項１乃至請求項５のいずれかに記載の軸受装置。   The bearing device according to claim 1, wherein the sliding bearing is a main bearing that supports a journal portion of the crankshaft.

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