WO2016157575A1

WO2016157575A1 - Connecting rod and cross-head type engine provided with same

Info

Publication number: WO2016157575A1
Application number: PCT/JP2015/077605
Authority: WO
Inventors: 西田　英朗; 拓造鴫原
Original assignee: 三菱重工業株式会社
Priority date: 2015-03-31
Filing date: 2015-09-29
Publication date: 2016-10-06
Also published as: JP6727758B2; CN107407323A; KR101957622B1; JP2016191463A; CN107407323B; KR20170103018A

Abstract

A connecting rod (18) connects a cross-head journal (7) and a crank pin (9) of a cross-head type engine (EG), and the connecting rod comprises: an oil supply path (15) that is formed extending along the longitudinal direction of the inside of the connecting rod and that joins a bearing surface (8a) of an end section (8A); an oil supply groove (16) that is formed extending along the circumferential direction of the bearing surface (8a) and that joins an opening (15c) at which the oil supply path (15) opens on the bearing surface (8a); and a bearing metal (11) which is attached to the bearing surface (8a) and which has a half-cylindrical shape. The location of the opening (15c) of the oil supply path (15) is at a location, on the bearing surface (8a), which is circumferentially outward in a range of pressure action (R) in which pressure from the cross-head journal (7) acts with the greatest force. The oil supply groove (16) is not formed within such range of pressure action (R).

Description

Connecting rod and crosshead type engine equipped with the same

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a connecting rod used in a crosshead type engine mounted mainly as a main ship of a ship, and a crosshead type engine provided with the same.

FIG. 6 is a longitudinal sectional view of a crosshead type engine for ships. 7 is a sectional view taken along the line VII-VII in FIG. 6, FIG. 8 is a plan view taken along the line VIII-VIII in FIG. 7, and FIG. 9 is a longitudinal sectional view taken along the line IX-IX in FIG.
In this crosshead type engine EG, the piston 2 is slidably inserted in the cylinder liner 1 extending in the vertical direction, and the crankshaft 3 is axially supported on the axis center extension line of the cylinder liner 1. The cross head 5 is provided slidably in the vertical direction between a pair of sliding plates 4 provided therebetween.

A crosshead-like crosshead journal 7 provided at the end of a piston rod 6 extending downward from the piston 2 is connected to the crosshead 5. In addition, the small end 8A of the connecting rod 8 is pivotally mounted on the cross head journal 7 and the large end 8B of the connecting rod 8 is rotatable on a crank pin 9 provided eccentrically to the crankshaft 3. It is pivotally supported. Therefore, when the piston 2 is depressed by the pressure P accompanying the combustion of the fuel, the crosshead 5 is also depressed and the connecting rod 8 is rotated to rotate the crankshaft 3, and this rotation is an output of the crosshead type engine EG. It becomes.

Caps

81 and 82 are attached to the small end 8A and the large end 8B of the connecting rod 8, respectively, so that the cross head journal 7 and the crank pin 9 are held in a clamp shape. Half

cylindrical bearing metals

11, 12 formed of a bearing material such as white metal are mounted on the bearing surface 8a of the small end 8A (81) and the bearing surface 8b of the large end 8B (82). ing.

As shown in FIGS. 7 to 9 and Patent Document 1 etc., the connecting rod 8 is shown in FIG. 6 with a small end 8A (bearing surface 8a) so as to extend along its internal longitudinal direction. An oil supply passage 15 is formed to communicate with the large end 8B (bearing surface 8b). The oil supply passage 15 communicates with the bearing surface 8a of the small end 8A and the bearing surface 8b of the large end 8B (see also FIG. 5 of Patent Document 1). The bearing surface 8a is formed with a plurality of oil supply grooves 16 extending along the circumferential direction.

As shown in FIG. 7, FIG. 8 and FIG. 5 of Patent Document 1, the inner diameter of the opening of the oil supply passage 15 at the bearing surface 8a of the small end 8A is larger than the width of the oil supply groove 16. . The opening position of the oil supply passage 15 corresponds to the central portion of the bearing surface 8a, that is, the center line C of the connecting rod 8 (see FIGS. 8 and 9).

At the time of operation of the crosshead type engine EG, after the lubricating oil supplied from the lubricating oil pump (not shown) to the crosshead 5 lubricates the space between the crosshead journal 7 and the bearing metal 11, the oil groove 16 and the oil passage 15 Between the bearing metal 12 and the crankpin 9 through the above.

Japanese Patent Application Publication No. 2007-532845

As described above, conventionally, the inner diameter of the opening of the oil supply passage 15 is larger than the width of the oil supply groove 16, and the opening of the oil supply passage 15 is located at the central portion of the bearing surface 8a. For this reason, in the pressure range R in which the pressure P (see FIG. 6) applied from the cross head journal 7 is the highest, the opening of the oil passage 15 and the oil groove 16 overlap and the back surface of the bearing metal 11 is The area of the non-contacting part was large.

Therefore, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, pressure deformation occurs such that the bearing metal 11 enters the opening of the oil supply passage 15. That is, as shown by the line D in FIG. 7, the distribution state of the maximum oil film pressure on the sliding surface 11 a of the bearing metal 11 drops sharply in the vicinity of the oil supply passage 15 and the height H around the oil supply passage 15 As shown in, it was a thing to stand up sharply.

Therefore, at the position where the maximum oil film pressure rises sharply to the height H (around the opening of the oil supply passage 15), the oil film of the lubricating oil supplied between the sliding surface 11a of the bearing metal 11 and the crosshead journal 7 Becomes thinner. Therefore, damage such as uneven wear may occur on the sliding surface 11a of the bearing metal 11, and the durability and reliability of the crosshead engine EG may be impaired.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a connecting rod capable of suppressing damage to bearing metals and enhancing engine durability and a crosshead type engine including the connecting rod. Do.

In order to solve the above-mentioned subject, the present invention adopts the following means.

That is, the connecting rod according to the first aspect of the present invention is for connecting between a crosshead journal provided at the end of a piston rod of a crosshead type engine and a crank pin provided on a crankshaft. An oil supply passage is formed to extend along the longitudinal direction inside the connecting rod and is connected to the bearing surface of the end of the connecting rod, and is formed to extend along the circumferential direction of the bearing surface. An oil supply groove connected to an opening opened on a bearing surface, and a half-cylindrical bearing metal mounted on the bearing surface, the position of the opening of the oil supply passage being the bearing surface The pressure applied from the crosshead journal is circumferentially outside the highest pressure range.

According to the connecting rod of the above-described configuration, the opening of the oil supply passage opened to the bearing surface at the end is located at the circumferentially outer side with respect to the pressure range in which the pressure applied from the cross head journal is the highest. For this reason, as in the conventional connecting rod, the opening of the oil supply passage is located in the pressure range, and there is no part where the bearing surface does not contact the back surface of the bearing metal in the pressure range.

For this reason, when the load (pressure) of the cross head journal acts on the bearing metal, no pressure deformation occurs so that the bearing metal enters the opening of the oil supply passage, and the maximum oil film pressure on the sliding surface of the bearing metal There is no sharp rise in the distribution. Therefore, a portion where the oil film of the lubricating oil becomes thin does not occur, and damage such as uneven wear does not occur on the sliding surface of the bearing metal, so the durability of the crosshead type engine can be enhanced.

A connecting rod according to a second aspect of the present invention is for connecting between a crosshead journal provided at the end of a piston rod of a crosshead type engine and a crank pin provided at a crankshaft, the connecting rod And an oil supply passage extending in the longitudinal direction along the longitudinal direction of the connecting rod and connected to the bearing surface at the end of the connecting rod, and the oil supply passage extending along the circumferential direction of the bearing surface. An oil supply groove connected to the opening opening upward and a half cylindrical bearing metal mounted on the bearing surface are provided, and the inner diameter of the opening of the oil supply passage is set equal to or less than the width dimension of the oil supply groove It is done.

According to the connecting rod of the above configuration, the opening of the oil supply passage opened to the bearing surface at the end thereof is opened to the inside of the oil supply groove formed along the circumferential direction of the bearing surface, and the opening of the oil supply passage The inner diameter of is set equal to or less than the width dimension of the oil supply groove. Therefore, as in the conventional case, the opening of the oil supply passage having an inner diameter larger than the width of the oil supply groove is present in the pressure range together with the oil supply groove, thereby increasing the area not contacting the back surface of the bearing metal in the pressure range. There is no

For this reason, similarly to the first aspect, when the load (pressure P) of the cross head journal acts on the bearing metal, it is possible to suppress the occurrence of pressure deformation so that the bearing metal enters the opening of the oil supply passage. As a result, it is possible to prevent the occurrence of damage such as uneven wear on the sliding surface of the bearing metal and to enhance the durability of the crosshead type engine.

In the above first and second aspects, the oil supply groove is formed on the bearing surface at a circumferentially outer position with respect to a pressure range in which the pressure applied from the cross head journal is the highest. May be

Thereby, when the load (pressure P) of the cross head journal acts on the bearing metal, the pressure deformation due to the bearing metal entering the recess of the oil supply groove disappears, and the sliding surface of the bearing metal suffers damage such as uneven wear. To improve the durability of the crosshead engine.

In each of the above aspects, the oil supply passage is branched from the large diameter portion extending along the longitudinal direction of the inside of the connecting rod and the end portion of the large diameter portion to communicate with the bearing surface and from the large diameter portion Also, a plurality of small diameter portions having a small inner diameter may be provided, and a tip of each of the small diameter portions may be the opening in the bearing surface.

In this way, a plurality of small diameter portions are branched from one large diameter portion and opened at a plurality of positions on the bearing surface, and the area of each opening is reduced without reducing the amount of oil passing through the oil supply passage. be able to. As a result, even if the opening is opened within the pressure range of the bearing surface, for example, due to design convenience, the opening area is small, so the area not in contact with the back surface of the bearing metal does not increase.

Therefore, when the load (pressure P) of the cross head journal acts on the bearing metal, the bearing metal does not undergo pressure deformation so as to enter the opening of the oil supply passage, and the durability of the cross head type engine can be enhanced. it can.

In the above aspect, the inner diameters of the plurality of small diameter portions are made different from each other, and in the bearing surface, the inner diameter of the small diameter portion located within the pressure range in which the pressure applied from the cross head journal is highest is It may be smaller than the inner diameter of the small diameter portion located at a place other than the above.

In this case, since the inner diameter of the small diameter portion located inside the pressure range is small, the area not in contact with the back surface of the bearing metal does not increase in the pressure range. For this reason, when the load (pressure P) of the cross head journal acts on the bearing metal, the bearing metal does not cause pressure deformation so as to enter the opening of the small diameter portion, thereby making the durability of the cross head type engine It can be enhanced.

In the above aspect, the plurality of small diameter portions may be branched from the large diameter portion at different angles.

The large diameter portion is preferably structurally located in the middle of the cross sectional area of the connecting rod. However, with the above configuration, the end of each small diameter portion can be relatively freely opened at an arbitrary position on the bearing surface with respect to the large diameter portion whose arrangement position is restricted. For this reason, the position of the opening in the bearing surface of each small diameter portion can be optimized, the pressure deformation of the bearing metal can be suppressed, and the durability of the crosshead type engine can be enhanced.

A plurality of the oil supply passages may be formed in parallel, and the openings of each of them may be communicated with different places of the bearing surface.

In this way, the inner diameter of each oil supply passage can be reduced and the area of each opening can be reduced without reducing the overall amount of oil supply, thereby suppressing the occurrence of pressure deformation such that the bearing metal enters the opening. At the same time, it is possible to suppress the decrease in strength of the connecting rod due to the formation of the oil supply passage, and to enhance the durability of the crosshead type engine.

A connecting rod according to a third aspect of the present invention is for connecting between a crosshead journal provided at the end of a piston rod of a crosshead type engine and a crank pin provided at a crankshaft, the connecting rod An oil supply passage formed to extend along the longitudinal direction of the inside of the cylinder, an oil supply groove formed to extend along the circumferential direction of the bearing surface at the end of the connecting rod, and the bearing surface attached The bearing passage side is in communication with the bottom of the oil supply groove without reaching the bearing surface.

According to the connecting rod of the above configuration, since the oil supply passage does not directly communicate with the bearing surface but communicates with the bottom of the oil groove formed in the bearing surface, only the oil groove is present as a recess in the bearing surface There is no recess other than the above. The lubricating oil collected in the oil supply groove can flow from the opening formed by the bottom of the oil supply groove and the end of the oil supply passage to the oil supply passage.

As described above, since there is no recess other than the oil supply groove in the bearing surface, when the bearing metal is mounted on the bearing surface, only the portion of the oil supply groove does not contact the back surface of the bearing metal. Therefore, when the load (pressure P) of the cross head journal acts on the bearing metal, the bearing metal does not enter the recess and cause pressure deformation, which causes damage such as uneven wear on the sliding surface of the bearing metal. To improve the durability of the crosshead engine.

Since the crosshead type engine according to the present invention includes any one of the connecting rods described above, pressure deformation of the bearing metal can be suppressed to improve engine durability.

As described above, according to the connecting rod and the crosshead engine provided with the connecting rod according to the present invention, damage to the bearing metal can be suppressed, and the durability of the engine can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of a connecting rod in alignment with the Ib-Ib line of (a). It is a figure which shows 2nd Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of a connecting rod in alignment with the IIb-IIb line of (a). It is a figure which shows 3rd Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of a connecting rod in alignment with the IIIb-IIIb line of (a). It is a figure which shows 4th Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of a connecting rod in alignment with the IVb-IVb line of (a). It is a figure which shows 5th Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod along the Vb-Vb line of (a), (c) Is a longitudinal cross-sectional view of the connecting rod taken along the line Vc-Vc in (b). FIG. 1 is a longitudinal sectional view of a marine crosshead engine. FIG. 7 is a longitudinal sectional view of a piston rod and a connecting rod taken along the line VII-VII of FIG. 6 showing a prior art. It is a top view of the bearing surface of a connecting rod by the VIII-VIII arrow of FIG. 7 which shows a prior art. FIG. 8 is a longitudinal cross-sectional view of a connecting rod taken along line IX-IX of FIG. 7 showing the prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
First, a connecting rod according to a first embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). The connecting rod 18 shown here has the same small end 8A as the conventional connecting rod 8 shown in FIGS. 8 and 9, and a cap (see 81 in FIG. 6) not shown is attached to the small end 8A. Thus, the cross head journal (see reference numeral 7 in FIG. 6) provided on the piston side is rotatably held. A cylindrical bearing metal 11 is mounted on the bearing surface 8a (not shown in FIG. 1A).

An oil supply passage 15 is formed inside the connecting rod 18, and an oil supply groove 16 extending along the circumferential direction is formed in the bearing surface 8a (three sides on each side of the center line C of the connecting rod 18 in this embodiment) A total of 6) are formed. The oil supply passage 15 has a circular hole-shaped large diameter portion 15a extending along the longitudinal direction of the inside of the connecting rod 18, and a V shape so as to sandwich the center line C of the connecting rod 18 from the end of the large diameter portion 15a. Into the bearing surface 8a and has a smaller inner diameter than the large diameter portion 15a (in this embodiment, two on each side, one on either side of the center line C of the connecting rod 18). ing.

The tip portions (openings 15 c) of the respective small diameter portions 15 b are respectively connected to the oil supply grooves 16 on both sides of the center line C of the connecting rod 18. The inner diameter of the opening 15 c in the present embodiment is larger than the width of the oil supply groove 16, but may be equal to or less than the width of the oil supply groove 16.

The pressure acts on the portion where the bearing surface 8a of the connecting rod 18 and the cross head journal 7 (see FIG. 6) contact, by the vertical movement of the piston 2. Among these, the high pressure range (pressure range) varies depending on the size of the engine, but at least the axial axial lowermost position where the crosshead journal 7 and the bearing surface 8a of the connecting rod 18 are in contact (connecting rod 18 Is a range including at least 120.degree. Across the center line C if it moves within a range of 120.degree. About the cross head journal.

The highest pressure P exerted from the cross head journal 7 on the bearing surface 8a is in the range of R shown in the drawing. The position of this pressure range R is circumferentially offset from the center line C of the connecting rod 18. The reason is that, as shown in FIG. 6, when the piston 2 is started to be depressed by the pressure P accompanying the combustion of fuel, the crankshaft 3 comes from the top dead center position of the piston 2 to a rotation angle θ of about 20 ° This is because the largest pressure is applied when the rod 18 is inclined. In the present embodiment, the range in which the pressure P acts the highest is defined as the pressure range R, but a relatively high range of pressure may be set as the pressure range.

In the bearing surface 8a, neither the small diameter portion 15b (opening 15c) of the oil supply passage 15 nor the oil supply groove 16 is formed in the pressure range R described above. The opening 15c of the small diameter portion 15b is at a position circumferentially outside with respect to the pressure range R, and is open at one end of the center of the three oil grooves 16 interrupted at this position. .

As shown in FIG. 1 (b), the small diameter portion 15b branched in a V shape from the upper end of the large diameter portion 15a of the oil supply passage 15 branches from the large diameter portion 15a at different angles α and β, respectively. Connected to In the present embodiment, the range in which the pressure P acts the highest is defined as the pressure range R, and the pressure range R is offset from the center line C in the circumferential direction. For this reason, the small diameter portion 15 b is branched from the oil supply passage 15 at different angles α and β. However, if the opening 15 c opens near the circumferential outer side of the pressure range R, it may be considered to make the angles α and β equal.

When the crosshead type engine EG (see FIG. 6) provided with the connecting rod 18 configured as described above operates, lubricating oil is supplied to the crosshead 5 from a lubricating oil pump (not shown). This lubricating oil lubricates between the cross head journal 7 and the sliding surface 11a of the bearing metal 11, passes through an oil hole (not shown) bored in the bearing metal 11, and enters the oil feeding groove 16, and further the opening 15c. Flow to the oil supply passage 15 (15a, 15b) to lubricate between the bearing metal 12 and the crank pin 9.

In the connecting rod 18, the position of the opening 15c of the oil supply passage 15 opened on the bearing surface 8a is circumferentially outside with respect to the pressure range R of the bearing surface 8a. Therefore, as in the conventional connecting rod 8 (see FIGS. 8 and 9), the bearing surface 8a does not occur on the back surface of the bearing metal 11 in the pressure range R when the opening 15c is positioned in the pressure range R. .

For this reason, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress pressure deformation such that the bearing metal 11 enters the opening of the oil passage 15 or the oil groove 16 It is possible to suppress the occurrence of a sharp rising portion in the distribution state of the maximum oil film pressure on the sliding surface 11 a of the metal 11. Therefore, generation of a portion where the oil film of lubricating oil is thin can be suppressed, whereby damage such as uneven wear on the sliding surface 11a of the bearing metal 11 can be suppressed, and thus the durability of the crosshead type engine EG can be enhanced. Can.

In the connecting rod 18, the oil supply groove 16 formed in the bearing surface 8 a is formed at a circumferentially outer position with respect to the pressure range R. For this reason, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress pressure deformation due to the bearing metal 11 entering the recess of the oil supply groove 16. Therefore, it is possible to suppress the occurrence of damage such as uneven wear on the sliding surface 11a of the bearing metal 11, and to improve the durability of the crosshead type engine EG.

Furthermore, the oil supply passage 15 includes a large diameter portion 15a extending along the longitudinal direction inside the connecting rod 18, and a small diameter portion 15b branched from an end of the large diameter portion 15a and leading to the bearing surface 8a. The tip of each of 15b is an opening 15c in the bearing surface 8a.

With this structure, two or more small diameter portions 15b are branched from one large diameter portion 15a and opened at a plurality of positions on the bearing surface 8a to reduce the amount of oil passing through the oil supply passage 15. Instead, the area of the individual openings 15c can be reduced. As a result, even if the opening 15 c opens into the pressure range R, for example, due to design considerations, the opening area can be minimized.

Therefore, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress pressure deformation such that the bearing metal 11 enters the opening 15c. Durability can be enhanced.

In the present embodiment, since the plurality of small diameter portions 15b are branched from the large diameter portion 15a at different angles α and β respectively, the end of each small diameter portion 15b with respect to the large diameter portion 15a having a restriction on the arrangement position The part can be relatively freely opened at any position of the bearing surface 8a. Therefore, the position of the opening 15c in the bearing surface 8a can be optimized, the pressure deformation of the bearing metal 11 can be suppressed, and the durability of the crosshead type engine EG can be enhanced.

Second Embodiment
Next, a connecting rod according to a second embodiment of the present invention will be described with reference to FIGS. 2 (a) and 2 (b). Also in the connecting rod 28, the oil supply passage 15 is branched from the end of the large diameter portion 15a and the large diameter portion 15a formed in a circular hole shape so as to extend along the longitudinal direction inside the connecting rod 28. A plurality of small diameter portions 15b communicating with the bearing surface 8a are provided, and the tip of each small diameter portion 15b is an opening 15c in the bearing surface 8a.

As shown in FIG. 2A, a total of six small diameter portions 15b are formed, three on each side of the center line C of the connecting rod 18. As shown in FIG. As shown in FIG. 2 (b), the small diameter portions 15b which are branched in a V shape from the upper end of the large diameter portion 15a to form the above two groups have the center line C as in the case of the first embodiment. It extends at a different angle to the

As shown in FIG. 2A, the three small diameter portions 15b are open inside the pressure range R, and the other three small diameter portions 15b are open outside the pressure range R. The small diameter portion 15b opened to the inside of the pressure range R is opened at the tip of the three oil grooves 16 formed in the same manner as the first embodiment, and the inner diameter of the opening 15c is the same as that of the oil groove 16 It is set equal to or less than the width dimension. The small diameter portion 15b opened to the outside of the pressure range R is also open at the tips of the three oiling grooves 16 on the opposite side, and the inner diameter of the opening 15c is set larger than the width dimension of the oiling groove 16 ing.

In the connecting rod 28 configured as described above, the openings 15 c of the six small diameter portions 15 b of the oil supply passage 15 opening on the bearing surface 8 a have two large and small inner diameters. Further, the inner diameter of the opening 15 c located in the pressure range R of the bearing surface 8 a is smaller than the inner diameter of the small diameter portion 15 b located outside the pressure range R, and the inner diameter is equal to the width dimension of the oil groove 16. It is set equal to or less than.

Therefore, as in the conventional connecting rod 8 (see FIGS. 8 and 9), the oil supply passage 15 having an inner diameter larger than the width of the oil supply groove 16 is present in the pressure range R together with the oil supply groove 16. There is no increase in the area not in contact with the back surface of the bearing metal 11 in the middle. Therefore, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress the occurrence of pressure deformation so that the bearing metal 11 enters the opening 15c of the small diameter portion 15b. As a result, the occurrence of damage such as uneven wear on the sliding surface 11 a of the bearing metal 11 can be suppressed, and the durability of the crosshead engine EG can be enhanced.

Third Embodiment
Next, a connecting rod according to a third embodiment of the present invention will be described with reference to FIGS. 3 (a) and 3 (b). In the connecting rod 38, two circular

oil supply passages

15A and 15B are formed in parallel with each other, and the openings 15c of the two

oil supply passages

15A and 15B are different places of the bearing surface 8a. It is in communication with Specifically, the pressure range is such that the two openings 15c are spaced apart in the circumferential direction of the bearing surface 8a with respect to the center line C of the connecting rod 8, and sandwich the pressure range R of the bearing surface 8a. It is disposed at a position circumferentially outside with respect to R.

The oil supply grooves 16 (three in each side across the center line C of the connecting rod 18 in the present embodiment, six in total in the present embodiment) are formed outside the pressure range R. The opening 15 c of the

oil supply passage

15 A, 15 B is in communication with the tip of the oil supply groove 16 at the center. The inner diameter of the opening 15 c is preferably set equal to or less than the width dimension of the oil supply groove 16.

In the connecting rod 38 configured as described above, the

oil supply passages

15A and 15B having two equal inner diameters are formed in parallel inside thereof, and the openings 15c of the

oil supply passages

15A and 15B are different from the bearing surface 8a. It communicates with the place. Therefore, the inner diameter of each of the

oil supply passages

15A and 15B can be reduced without reducing the overall amount of oil supply, and the area of each of the openings 15c can be reduced.

In addition to the fact that the area of the opening 15c of the

oil supply passages

15A and 15B can be reduced as described above, the

oil supply passages

15A and 15B (openings 15c) communicate circumferentially outward with respect to the pressure range R of the bearing surface 8a. Since the inner diameter of the opening 15c is set equal to or less than the width dimension of the oil supply groove 16 and the oil supply groove 16 is not formed in the pressure range R, There is no recess on the back surface where the bearing surface 8a does not contact.

For this reason, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress the occurrence of pressure deformation so that the bearing metal 11 enters the recess in the pressure range R, and damage to the bearing metal 11 To improve the durability of the crosshead engine EG.

Moreover, since the inner diameters of the

oil supply passages

15A and 15B can be reduced as described above, the reduction in strength of the connecting rod 8 caused by the formation of the

oil supply passages

15A and 15B can be suppressed. Can be enhanced. The two

oil supply passages

15A and 15B are formed parallel to the center line C of the connecting rod 38, so that their processing is easy. Two or more

fuel supply passages

15A, 15B may be formed, or the inner diameters may be made different.

Fourth Embodiment
Next, a connecting rod according to a fourth embodiment of the present invention will be described with reference to FIGS. 4 (a) and 4 (b). Also in the connecting rod 48, the oil supply passage 15 branches from the end portion of the large diameter portion 15a having a circular hole shape extending along the longitudinal direction inside the connecting rod 28, and leads to the bearing surface 8a. A plurality of small diameter portions 15 b are combined and configured. The tip of each small diameter portion 15b is an opening 15c in the bearing surface 8a.

As shown in FIG. 4 (a), the number of the small diameter portions 15b is, for example, four and radially extends from the large diameter portion 15a, and the respective openings 15c are opened at a plurality of locations on the bearing surface 8a. ing. More specifically, all of the openings 15c are open to the inside of the three oil supply grooves 16 formed in the circumferential direction of the bearing surface 8a. Three openings 15 c are opened in the center oil supply groove 16, and one opening 15 c is opened in the oil supply grooves 16 on both sides. The inner diameter of each small diameter portion 15 b (opening 15 c) is set equal to or smaller than the width dimension of the oil supply groove 16. It is not necessary to open all the openings 15 c in the oil supply groove 16, and only a part of the openings 15 c may be opened in the oil supply groove 16.

Since the connecting rod 48 configured in this way branches a large number of small diameter portions 15b from one large diameter portion 15a and opens it at a plurality of positions on the bearing surface 8a, the amount of oil passing through the oil supply passage 15 The area of the individual openings 15c can be reduced without reduction.

These openings 15 c are disposed within the pressure range R of the bearing surface 8 a, but each opening 15 c is open to the inside of the oil supply groove 16, and the inner diameter is set equal to or less than the width dimension of the oil supply groove 16 Therefore, the opening 15 c whose inner diameter is larger than the width of the oil supply groove 16 does not open into the pressure range R.

For this reason, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, it is possible to suppress the occurrence of pressure deformation so that the bearing metal 11 enters the opening 15c, preventing damage to the bearing metal 11. Thus, the durability of the crosshead engine EG can be enhanced.

Fifth Embodiment
Next, a connecting rod according to a fifth embodiment of the present invention will be described with reference to FIGS. 5 (a), (b) and (c). The connecting rod 58 is formed, for example, with three oil grooves 16 extending along the circumferential direction on the bearing surface 8a of the small end 8A, and the central groove is formed deeper than the grooves on both sides It is done.

A circular oil supply passage 15 is formed in the inside of the connecting rod 58 so as to extend along the longitudinal direction, and the end of the oil supply passage 15 on the bearing surface 8 a side reaches the bearing surface 8 a It does not communicate with the bottom of the central oil supply groove 16. For this reason, a slit-like opening 15 c communicating with the oil supply passage 15 is formed at the center of the central oil supply groove 16 in the longitudinal direction. The length of the opening 15 c is equal to the inner diameter of the oil supply passage 15, and the width of the opening 15 c is equal to the width of the oil supply groove 16.

According to the connecting rod 58 of the above configuration, as shown in FIGS. 5 (a) and 5 (c), although the oil supply passage 15 is disposed to overlap the pressure range R of the bearing surface 8a, this oil supply passage Since the reference numeral 15 does not directly communicate with the surface of the bearing surface 8a but communicates only with the bottom of the oil supply groove 16, the oil supply passage 15 is not exposed as a recess in the bearing surface 8a. For this reason, only three oil supply grooves 16 are present as recesses in the bearing surface 8a, and no other recesses are present. The lubricating oil collected in the oil supply groove 16 can flow to the oil supply passage 15 from an opening 15 c formed by overlapping the bottom of the oil supply groove 16 at the center and the end of the oil supply passage 15.

As described above, since there is no recess in the bearing surface 8a other than the oil supply groove 16, when the bearing metal 11 is mounted on the bearing surface 8a, only the portion of the oil supply groove 16 does not contact the back surface of the bearing metal 11. . Therefore, when the load (pressure P) of the cross head journal 7 acts on the bearing metal 11, the bearing metal 11 does not enter into the recess such as the opening 15c to cause pressure deformation, thereby sliding the bearing metal 11 The occurrence of damage such as uneven wear on the surface 11a can be prevented, and the durability of the crosshead type engine EG can be enhanced.

As described above, according to the connecting

rods

18, 28, 38, 48, 58 and the crosshead type engine EG having the same according to the above embodiments, the bearing surface of the end 8A of the connecting rods 18 to 58 By suppressing the pressure deformation of the bearing metal 11 due to the formation of the recess by the oil supply passage 15 communicating with 8a, there is no place where the maximum oil film pressure on the sliding surface 11a of the bearing metal 11 rapidly increases. It is possible to suppress the occurrence of damage such as wear and to improve the durability of the engine.

The present invention is not limited only to the configuration of the above embodiment, and can be appropriately modified or improved, and an embodiment with such modification or improvement is also included in the scope of the present invention. .

For example, in each of the above embodiments, an example in which the present invention is applied to the small end 8A side of the connecting rods 18 to 58 has been described, but the present invention may be applied to the large end 8B side. In addition, the embodiments may be combined or another configuration may be added.

1 cylinder liner 2 piston 3 crank shaft 6 piston rod 7 cross head journal 8A small end (end)
8a Bearing surface 9 Crank pin 11

Bearing metal

15, 15A, 15B Oil supply passage 15a Large diameter portion 15b Small diameter portion 15c Opening 16

Oil supply groove

18, 28, 38, 48, 58 Connecting rod EG Crosshead type engine P Pressure R Pressure range Angle of small diameter part of α, β

Claims

A connecting rod for connecting between a crosshead journal provided at the end of a piston rod of a crosshead engine and a crankpin provided at a crankshaft,
An oil supply passage formed to extend along the longitudinal direction inside the connecting rod and connected to the bearing surface at the end of the connecting rod;
An oil supply groove which is formed to extend along the circumferential direction of the bearing surface, and the oil supply passage is connected to an opening opened on the bearing surface;
A half cylindrical bearing metal mounted on the bearing surface;
Equipped with
The connecting rod has a position circumferentially outside of a pressure range in which the pressure applied from the cross head journal acts the highest at the bearing surface.
A connecting rod for connecting between a crosshead journal provided at the end of a piston rod of a crosshead engine and a crankpin provided at a crankshaft,
An oil supply passage formed to extend along the longitudinal direction inside the connecting rod and connected to the bearing surface at the end of the connecting rod;
An oil supply groove which is formed to extend along the circumferential direction of the bearing surface, and the oil supply passage is connected to an opening opened on the bearing surface;
A half cylindrical bearing metal mounted on the bearing surface;
Equipped with
An inner diameter of the opening of the oil supply passage is set to be equal to or less than a width dimension of the oil supply groove.
The connecting rod according to claim 1 or 2, wherein the oil supply groove is formed at a position circumferentially outside the pressure range in which the pressure applied from the cross head journal acts the highest on the bearing surface.
The oil supply passage includes a large diameter portion extending along the longitudinal direction of the inside of the connecting rod, and a plurality of branch portions branched from an end of the large diameter portion to communicate with the bearing surface and having a smaller inner diameter than the large diameter portion. The connecting rod according to any one of claims 1 to 3, further comprising a small diameter portion, wherein a tip end of each of the small diameter portions is the opening in the bearing surface.
The plurality of small diameter portions are different in inner diameter from each other, and the inner diameter of the small diameter portion located inside the pressure range in which the pressure applied from the cross head journal is highest is located in the other place in the bearing surface. The connecting rod according to claim 4, which is smaller than the inner diameter of the small diameter portion.
The connecting rod according to claim 4 or 5, wherein the plurality of small diameter portions branch from the large diameter portion at different angles.
The connecting rod according to any one of claims 1 to 3, wherein a plurality of the oil supply passages are formed in parallel, and the openings of each of the oil supply passages are communicated with different places of the bearing surface.
A connecting rod for connecting between a crosshead journal provided at the end of a piston rod of a crosshead engine and a crankpin provided at a crankshaft,
A refueling passage formed to extend along the longitudinal direction inside the connecting rod;
An oil supply groove formed to extend along the circumferential direction of the bearing surface at the end of the connecting rod;
A half cylindrical bearing metal mounted on the bearing surface;
Equipped with
A connecting rod whose end on the bearing surface side communicates with the bottom of the lubrication groove without reaching the bearing surface.
A crosshead engine provided with the connecting rod according to any one of claims 1 to 8.