JP2015165143A - Oil scraper ring and internal combustion engine - Google Patents

Abstract

An object of the present invention is to provide an oil scraping ring and an internal combustion engine capable of improving oil scraping performance. An oil scraping ring 22 is provided around a piston rod of an internal combustion engine. The oil scraping ring 22 includes a hollow region and a solid region, and at least the solid region includes a piston rod. On the other hand, a notch portion 1 is formed by notching in the center direction from the outer peripheral surface on the opposite side. Since the portion where the notch 1 is formed has a smaller radial width than the portion where the notch 1 is not formed, the rigidity of the oil scraping ring 22 can be reduced. [Selection] Figure 3

Description

  The present invention relates to an oil scraping ring and an internal combustion engine housed in a stuffing box of the internal combustion engine.

  In marine or industrial low-speed two-cycle internal combustion engines, etc., a partition is provided between the scavenging chamber (combustion chamber) and the crank chamber, and the piston rod reciprocates between the scavenging chamber and the crank chamber through the partition. To do. A stuffing box that freely supports the piston rod is installed on the partition wall. Inside the stuffing box, a seal ring and an oil scraping ring are provided to improve the airtightness of the scavenging chamber. Also, combustion products in the scavenging chamber, cylinder lubricating oil, etc. enter the crank chamber and prevent system oil in the crank chamber from being contaminated, and the system oil adhering to the piston rod in the crank chamber is swept up into the scavenging chamber. To prevent.

  Patent Document 1 discloses a technique in which the cross section of the oil scraping ring is substantially M-shaped, I-shaped, or H-shaped in order to make good follow-up contact with the outer peripheral surface of the piston rod and exhibit good oil-scraping performance. ing. Further, Patent Document 2 discloses a technique for improving the sealing effect by adopting a seal ring structure having fewer than three separation parts composed of two or one ring parts.

Japanese Patent No. 3957778 JP 60-65959 A

  The above-described oil scraping ring in the stuffing box may be divided into, for example, three parts in the circumferential direction, and a tension spring (coil spring) is wound around the outer circumferential surface and tightened from the outer circumferential surface toward the central direction. Yes.

  When the outer diameter of the piston rod increases, the circumferential length of each of the three divided members becomes longer. Usually, under the same load condition, the amount of deflection increases as the length of the material increases. For this reason, if the circumferential length of the divided member is increased, the amount of bending is increased, so that it is considered that the divided member easily comes into full contact with the outer circumferential surface of the piston rod.

  However, in order to ensure that the divided member is supported, the radial width of the divided member cannot be reduced. As a result, even when the peripheral length of the split member is long, the rigidity of the split member is high, and the inner peripheral surface of the split member and the outer peripheral surface of the piston rod are difficult to contact.

  In addition, when the center angle of the divided member is 120 ° or less by the inventors and the three metal divided members are combined, each division of the metal oil scraping ring increases as the outer diameter of the piston rod increases. The knowledge that the dimensional error between the arc-shaped inner diameter of the member and the outer diameter of the piston rod increases and the gap between the oil scraping ring and the piston rod increases is obtained. Further, it was found that when the circumferential length of the divided member is long, the contact surface pressure of the divided member with respect to the piston rod tends to decrease in the central portion as compared with the end portion of the divided member.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the oil scraping ring and internal combustion engine which can improve the scraping-off performance of oil.

In order to solve the above problems, the oil scraping ring and the internal combustion engine of the present invention employ the following means.
That is, an oil scraping ring according to the present invention is an oil scraping ring provided around a piston rod of an internal combustion engine, and the oil scraping ring includes a hollow region and a solid region, and at least the medium In the actual region, a first notch is formed by notching in the center direction from the outer peripheral surface opposite to the piston rod.

  According to this configuration, the oil scraping ring that scrapes off the oil attached to the outer peripheral surface of the piston rod includes a hollow region and a solid region, and at least the solid region of the oil scraping ring includes: Since the first notch portion is cut away from the outer peripheral surface toward the center direction, the radial width is smaller than the portion where the first notch portion is not formed, Small rigidity. As a result, the rigidity of the oil scraping ring can be reduced.

  An oil scraping ring according to the present invention is a circumferentially divided oil scraping ring provided around a piston rod of an internal combustion engine, and each divided member of the oil scraping ring extends from an end portion along the circumferential direction. A notched second notch is formed.

  According to this configuration, the divided members are arranged in the circumferential direction to configure the oil scraping ring, and the oil scraping ring scrapes off the oil adhering to the outer peripheral surface of the piston rod. Since the second cutout portion is formed in the radial direction from the end portion of each divided member along the circumferential direction, a gap portion is formed in the radial direction. Rigidity is small compared to the non-formed part. As a result, the rigidity of the divided member can be reduced. And the contact surface pressure which arises in the edge part of a division member can be reduced, and the contact surface pressure in the circumferential direction of a division member can be equalized. As a result, the oil scraping ring and the piston rod can be brought into full contact with each other over the circumferential direction.

  An internal combustion engine according to the present invention includes a stuffing box in which the oil scraping ring is accommodated.

  According to the present invention, oil scraping performance can be improved.

It is a longitudinal section showing a diesel engine concerning one embodiment of the present invention. It is a longitudinal cross-sectional view which shows the stuffing box of the diesel engine which concerns on one Embodiment of this invention. It is a transverse cross section showing the 1st example of the division member which constitutes the oil scraping ring concerning one embodiment of the present invention. It is the longitudinal cross-sectional view cut | disconnected by the AA line of FIG. It is the longitudinal cross-sectional view cut | disconnected by the BB line of FIG. It is a cross-sectional view which shows the 2nd Example which comprises the oil scraping ring which concerns on one Embodiment of this invention. It is the longitudinal cross-sectional view cut | disconnected by CC line of FIG. It is the longitudinal cross-sectional view cut | disconnected by the DD line | wire of FIG. It is a cross-sectional view which shows the 3rd Example which comprises the oil scraping ring which concerns on one Embodiment of this invention. It is the longitudinal cross-sectional view cut | disconnected by the EE line | wire of FIG. It is the longitudinal cross-sectional view cut | disconnected by the FF line of FIG. It is a top view which shows the 4th Example which comprises the oil scraping ring which concerns on one Embodiment of this invention. It is a top view which shows the 5th Example which comprises the oil scraping ring which concerns on one Embodiment of this invention.

Embodiments according to the present invention will be described below with reference to the drawings.
The stuffing box according to this embodiment is applied to a diesel engine 10 having a crosshead structure, for example. As shown in FIG. 1, the diesel engine 10 is divided into a scavenging chamber 11 and a crank chamber 12, and includes a piston 13, a piston rod 14, a crosshead 15, a connecting rod 16, a crankshaft 17, and the like. The crosshead 15 is pivotally connected to one end of the piston rod 14 and one end of the connecting rod 16, and the crosshead 15 reciprocates while sliding on a sliding plate 20 fixed to the body side of the diesel period 10. Move. The pressure pushing the piston 13 is transmitted from the piston rod 14 to the crankshaft 17 via the connecting rod 16.

  The stuffing box 18 is provided in a partition wall 19 that separates the scavenging chamber 11 and the crank chamber 12, and the piston rod 14 reciprocates inside the stuffing box 18.

  As shown in FIG. 2, the stuffing box 18 includes a casing 21, a plurality of metal oil scraping rings 22, and a seal ring 23. The plurality of oil scraping rings 22 and the seal ring 23 are accommodated in the casing 21 side by side in the axial direction.

The oil scraping ring 22 is stored in a plurality of stages, and two oil scraping rings 22 are stored in each stage in the axial direction. Between the stages of the oil scraping ring 22, a support portion 24 that supports the oil scraping ring 22 is formed in the casing 21. The oil scraping ring 22 has a radial width that is supported by the support portion 24.
In the casing 21, a drain passage 25 and a drain chamber 26 through which oil discharged from the piston rod 14 flows to the outside are formed on the outer peripheral surface 22 a side of the oil scraping ring 22.

  The oil scraping ring 22 is divided into three in the circumferential direction, and an annular oil scraping ring 22 is configured by combining three divided members 22A. As shown in FIG. 3, the center angle of each divided member 22A is smaller than 120 °, and when the three divided members 22A are arranged in the circumferential direction, a gap 27 is formed between the divided members 22A.

  A tension spring 29 (see FIG. 1) is wound around the outer peripheral surface 22a of the oil scraping ring 22 along the circumferential direction, and the oil scraping ring 22 is tightened from the outer peripheral surface 22a toward the center by the tension spring 29. ing. Further, since the tension spring 29 is biased, the oil scraping ring 22 follows the cylinder rod 14 even when the cylinder rod 14 sways not only in the axial direction but also in a direction perpendicular to the axial direction. Can continue to scratch.

  The oil scraping ring 22 is formed with discharge holes 28 for discharging oil at a plurality of locations in the circumferential direction (see FIG. 3). The discharge hole 28 is formed through the oil scraping ring 22 in the radial direction, that is, from the inner peripheral surface 22b side to the outer peripheral surface 22a side. The discharge hole 28 is formed by a tool such as a milling cutter.

  Next, with reference to FIGS. 3-13, the notch part formed in the division member 22A which comprises the oil scraping ring 22 which concerns on this embodiment is demonstrated.

(First embodiment)
As shown in FIGS. 3 to 5, each divided member 22 </ b> A is formed with a slit groove 1 cut out in the radial direction from the outer peripheral surface 22 a side. The slit groove 1 is an example of a notch. The length of the slit groove 1 is from the outer peripheral surface 22a side to the middle of the dividing member 22A in the radial direction. The groove width of the slit groove 1 is, for example, constant. The slit groove 1 penetrates from the upper surface to the lower surface of the dividing member 22A. The degree of rigidity of the dividing member 22A is adjusted according to the length and width of the slit groove 1. The groove width of the slit groove 1 may be such that the outer peripheral surface 22a side of the dividing member 22 is wide and gradually becomes narrower.

The portion where the slit groove 1 is formed has a smaller rigidity than the portion where the slit groove 1 is not formed because the radial width of the dividing member 22A is small.
By forming the slit groove 1 described above, the rigidity of the oil scraping ring 22 can be reduced in a relatively narrow range near the portion where the slit groove 1 is formed. Moreover, the slit groove | channel 1 can be formed with simple cutting tools, such as a drill and a cutter.

  The slit groove 1 may be provided in a hollow region (see FIG. 5) in which the above-described discharge hole 28 is formed, that is, in each of the top plate and the bottom plate of the dividing member 22A, or the discharge hole 28 is not formed. It may be provided in a real area (see FIG. 4). The degree of rigidity can be adjusted depending on whether it is formed in a hollow region or a solid region. In addition, providing the slit groove 1 in the solid area can lower the rigidity than providing the slit groove 1 in the hollow area.

  For example, the slit groove 1 is formed with, for example, about five in one division member 22A. Thereby, rigidity can be reduced at an arbitrary circumferential position of the dividing member 22A. Note that it is desirable to form the slit groove 1 so that the rigidity of the end portion of the dividing member 22A is smaller than that of the central portion. Thereby, the contact surface pressure which arises in the edge part of 22 A of division members can be reduced, and the contact surface pressure in the circumferential direction of 22 A of division members can be equalize | homogenized. As a result, the oil scraping ring 22 and the piston rod 14 can be brought into full contact over the circumferential direction.

(Second embodiment)
As shown in FIGS. 6 to 8, the end portion of the slit groove 1 may be formed with a circular portion 2 having a diameter longer than the width of the slit groove 1. Thereby, stress concentration at the end of the slit groove 1 can be avoided, and the durability of the divided member 22A can be improved. The circular portion 2 is formed with a simple cutting tool such as a drill. In addition, since the stress concentration at the distal end portion on the radially inner side of the slit groove 1 can be relaxed as compared with the slit groove 1 of the first embodiment, the durability of the oil scraping ring can be enhanced.

(Third embodiment)
As shown in FIGS. 9 to 11, the cutout portion 3 may be formed in an arc shape instead of the slit groove 1. The arc-shaped notch 3 is formed from the outer peripheral surface 22a side to the middle of the dividing member 22A in the radial direction.

  The portion in which the arc-shaped cutout portion 3 is formed has a smaller rigidity than the portion in which the cutout portion 3 is not formed because the radial width of the dividing member 22A is small.

  By forming the arc-shaped cutout portion 3 described above, the rigidity of the oil scraping ring 22 can be reduced in a relatively wide range as compared with the case where the slit groove 1 is formed. Further, the arc-shaped cutout portion 3 can be formed with a simple cutting tool such as a milling cutter, and the same tool as the above-described discharge hole 28 can be used. Therefore, the operation can be simplified. Further, since the stress concentration on the radially inner tip of the notch 3 can be relaxed more than the slit groove 1 of the first embodiment, the durability of the oil scraping ring can be enhanced.

  The arc-shaped notch 3 may be provided in the hollow region where the discharge hole 28 is formed, that is, in each of the top plate and the bottom plate of the dividing member 22A (see FIG. 11), or the discharge hole 28 is formed. You may provide in the solid area | region which is not done (refer FIG. 10). As in the case of the slit groove 1, the degree of rigidity can be adjusted depending on whether it is formed in a hollow region or a solid region.

(Fourth embodiment)
As shown in FIG. 12, a plurality of slit grooves 4 are formed in the vicinity of the end portion of the dividing member 22A at intervals similar to the width of the slit groove 4, and the end portion of the dividing member 22A is formed in a comb shape. Also good. The comb-shaped region is determined according to the region where the rigidity is reduced. In this case, the rigidity can be further reduced as compared with the case where only one slit groove 1 is provided.

  Further, it is desirable that the depth of each slit groove 4 forming the comb-shaped portion is deepest at the end portion side of the dividing member 22A and becomes shallower toward the center of the dividing member 22A. Thereby, the rigidity of the edge part of 22 A of division members becomes small compared with a center part, and the contact surface pressure which arises in the division member 22A edge part can be reduced. As a result, the contact surface pressure in the circumferential direction of the divided member 22A is made uniform, and the oil scraping ring 22 and the piston rod 14 can be brought into full contact over the circumferential direction.

  By arranging the plurality of slit grooves 4 in the circumferential direction at the end of the dividing member 22A, the rigidity of the end of the dividing member 22A becomes smaller than that of the central portion, and the contact surface pressure generated at the end of the dividing member 22A. Can be reduced. As a result, the contact surface pressure in the circumferential direction of the divided member 22A is made uniform, and the oil scraping ring 22 and the piston rod 14 can be brought into full contact over the circumferential direction.

(5th Example)
As shown in FIG. 13, the split member 22A is formed with a slit groove 5 cut out from the end portion along the circumferential direction in the vicinity of the middle in the radial direction. The slit groove 5 is an example of a notch.

  The length of the slit groove 5 is from the end to the middle in the circumferential direction of the dividing member 22A. The groove width of the slit groove 5 is constant, for example. The slit grooves are formed at both ends of the dividing member 22A. The slit groove 5 penetrates from the upper surface to the lower surface of the dividing member 22A. The length and width of the slit groove 5 are determined according to the region where the rigidity is lowered and the degree of rigidity.

  Since the gap groove portion is formed in the radial direction of the dividing member 22A, the portion where the slit groove 5 is formed is less rigid than the portion where the slit groove 5 is not formed.

  By forming the slit groove 5 described above, the rigidity of the oil scraping ring 22 can be reduced in a relatively wide range of the end portion of the divided member 22A where the slit groove 5 is formed. Moreover, the slit groove | channel 5 can be formed with simple cutting tools, such as a drill and a cutter.

  The slit groove 5 may also be provided in the hollow region in which the discharge hole 28 is formed, that is, each of the top plate and the bottom plate of the dividing member 22A, or a solid region in which the discharge hole 28 is not formed. May be provided. The degree of rigidity can be adjusted by forming the hollow region, the solid region, or both in the circumferential direction.

  As described above, according to the present embodiment, it is possible to reduce the rigidity of the oil scraping ring 22 which is a member that directly scrapes the oil attached to the piston rod 14. Further, by making the rigidity of the end portion of the divided member 22A smaller than that of the central portion and reducing the contact surface pressure generated at the end portion of the divided member 22A, it is possible to ensure uniform contact surface pressure in the circumferential direction of the divided member 22A. . As a result, the oil scraping ring 22 and the piston rod 14 can be brought into full contact over the circumferential direction. Even when the outer diameter of the piston rod 14 is increased and the dimensional error between the arc-shaped inner diameter of the divided member 22A and the outer diameter of the piston rod 14 becomes large, the inner peripheral surface of the oil scraping ring 22 and the piston rod The outer peripheral surface of 14 comes into contact over almost the entire length, and the oil can be surely scraped off from the outer peripheral surface of the piston rod 14.

  In particular, in the long stroke diesel engine 10 in which the working radius of the crankshaft 17 is long, even when the piston rod 14 sways in a direction perpendicular to the axial direction, in this embodiment, the followability of the oil scraping ring 22 is high. It is difficult to form a gap between the inner peripheral surface 22b of the oil scraping ring 22 and the outer peripheral surface of the piston rod 14, and the oil scraping performance can be improved.

  Further, the slit groove and the arc-shaped cutout portion of the present embodiment can be realized by a simple cutting process. Therefore, the rigidity of the oil scraping ring 22 already used and the oil scraping ring 22 stored as stock can be easily reduced if there is a ship or a simple work place and a relatively simple cutting tool. Can be made.

  Further, unlike the present embodiment, when the cutting portion of the oil scraping ring 22 is one place or when the oil scraping ring 22 is divided into two parts, the rigidity is increased, and the rigidity is lowered as in the present embodiment. Even so, the contact is bad. In addition, when the cut portion of the oil scraping ring 22 is provided at one place, the oil scraping ring 22 cannot be removed in the radial direction of the piston rod 14, and therefore maintainability is poor. On the other hand, in this embodiment, since the oil scraping ring 22 is divided into three parts, it is possible to improve the oil scraping performance while avoiding an increase in the number of parts by increasing the number of divisions to four or more. In addition, replacement work during maintenance can be performed efficiently.

1, 2, 4 Slit groove (first notch)
3 Notch (first notch)
5 Slit groove (second notch)
10 Diesel engine (internal combustion engine)
11 Scavenging chamber 12 Crank chamber 14 Piston rod 18 Stuffing box 22 Oil scraping ring 22A Split member 23 Seal ring 28 Discharge hole 29 Tension spring

Claims (3)

An oil scraping ring provided around a piston rod of an internal combustion engine,
The oil scraping ring includes a hollow region and a solid region, and at least the solid region includes a first cut that is notched in the center direction from the outer peripheral surface on the opposite side to the piston rod. Oil scraping ring with a notch. A circumferentially divided oil scraping ring provided around a piston rod of an internal combustion engine,
Each of the divided members of the oil scraping ring is an oil scraping ring in which a second notch portion that is notched from the end portion along the circumferential direction is formed.   An internal combustion engine comprising a stuffing box in which the oil scraping ring according to claim 1 or 2 is accommodated.

Images