Internal combustion engine

Abstract

An internal combustion engine (1) includes: a cylinder (10) in which a piston (15) reciprocates; a cylinder head (25) located above the cylinder (10); a gasket (30) provided between the cylinder (10) and the cylinder head (25); a stepped portion (20) formed at an upper end portion of an inner peripheral surface (11) of the cylinder (10) and located below the gasket (30); a ring member (40) provided to the stepped portion (20) and having a cylindrical shape; and a protruding portion (45) formed in such a manner as to protrude from the ring member (40) and engage into a lower surface (31) of the gasket (30).

Description

Technical Field

[0001] This disclosure relates to internal combustion engines including cylinders and pistons. Background Technology

[0002] In internal combustion engines, a ring member is provided on a stepped portion formed on the upper part of the inner circumferential surface of the cylinder. For example, Japanese Unexamined Patent Application Publication No. 2017-089410 discloses an internal combustion engine in which a scraper ring is provided on the stepped portion to remove putty adhering to the piston.

[0003] Existing technology

[0004] Patent documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-089410 Summary of the Invention

[0006] The problem to be solved by the present invention

[0007] Because the ring member described above is not fixed to the stepped portion, it may move due to vibration and come into contact with the piston during the operation of the internal combustion engine. When the ring member contacts the piston, at least one of the ring member or the piston may be damaged.

[0008] This disclosure is made in consideration of these points, and the purpose of this disclosure is to prevent the ring member from contacting the piston during operation of the internal combustion engine.

[0009] means for solving problems

[0010] One aspect of this disclosure provides an internal combustion engine, including: a cylinder in which a piston reciprocates; a cylinder head located above the cylinder; a gasket disposed between the cylinder and the cylinder head; a stepped portion formed at an upper end of an inner circumferential surface of the cylinder and located below the gasket; a ring member disposed to the stepped portion and having a cylindrical shape; and a protrusion formed such that it protrudes from the ring member and engages with a lower surface of the gasket.

[0011] In addition, the edge of the tip of the protrusion can engage with the lower surface of the washer.

[0012] In addition, the side surface of the gasket can be positioned closer to the piston in the radial direction of the cylinder than the inner circumferential surface of the stepped portion, and the protruding portion can protrude from the upper surface of the ring member.

[0013] In addition, the protruding part can be formed into a ring shape along the circumferential direction on the upper part of the ring member.

[0014] In addition, multiple protrusions may be formed on the upper surface of the ring member at predetermined intervals in the circumferential direction.

[0015] In addition, multiple protrusions may be formed on the upper surface of the ring member in the radial direction at predetermined intervals.

[0016] Furthermore, when the piston is observed in a plane, the outer peripheral surface of the piston can be elliptical, and the inner peripheral surface of the ring member facing the outer peripheral surface can also be elliptical, such that when the ring member is observed in a plane, the inner peripheral surface of the ring member is separated from the outer peripheral surface by a predetermined distance.

[0017] In addition, the ring member may have a protruding portion that protrudes outward from the outer peripheral surface of the ring member in the radial direction, and a recessed portion may be formed on the inner peripheral surface of the step portion, with the protruding portion fitting into the recessed portion.

[0018] Furthermore, the protruding portion can be formed from one end of the ring member in the axial direction to the other end.

[0019] Furthermore, when the ring component is observed in a plane, its outer peripheral surface can be a true circle.

[0020] Effects of the present invention

[0021] According to this disclosure, the ring component can be prevented from contacting the piston during operation of the internal combustion engine. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the internal configuration of an internal combustion engine 1 according to an embodiment.

[0023] Figure 2 This is a schematic diagram showing an internal combustion engine 100 according to a comparative example.

[0024] Figure 3 This is a schematic diagram illustrating an improved example of internal combustion engine 1.

[0025] Figure 4 This is a schematic diagram showing an internal combustion engine 100 according to a comparative example. Detailed Implementation

[0026] <International Internal Combustion Engine Configuration>

[0027] Reference Figure 1 Describe the configuration of an internal combustion engine according to an implementation method.

[0028] Figure 1 This is a schematic diagram showing the internal configuration of an internal combustion engine 1 according to an embodiment. Figure 1 The diagram shows only a portion of the internal combustion engine 1, and other components have been omitted for ease of explanation.

[0029] An internal combustion engine 1 is, for example, an engine installed in a vehicle. Figure 1As shown, the internal combustion engine 1 includes a cylinder 10, a piston 15, a stepped portion 20, a cylinder head 25, a gasket 30, and a ring member 40.

[0030] The cylinder 10 is made of metal and formed into a cylindrical shape. The piston 15 is housed in the cylinder 10.

[0031] Piston 15 reciprocates between top dead center and bottom dead center within cylinder 10. Figure 1 In the piston 15, the piston is located at top dead center. Piston rings 16 are fitted into grooves formed on the outer peripheral surface 15a of the piston 15.

[0032] like Figure 1 As shown, the stepped portion 20 is located at the upper end of the inner circumferential surface 11 of the cylinder 10. When the piston 15 is at top dead center, the stepped portion 20 is located above the piston ring 16. The stepped portion 20 is formed such that it extends circumferentially downwards from the inner circumference of the inner circumferential surface 11 of the cylinder 10. The stepped portion 20 is located below the washer 30. The stepped portion has an inner circumferential surface 22 perpendicular to the bottom surface of the stepped portion 20.

[0033] The cylinder head 25 is located above the cylinder 10. The cylinder head 25 is made of metal, and for example, of the same material as the cylinder 10.

[0034] A gasket 30 is disposed between the cylinder 10 and the cylinder head 25. The gasket 30 has the function of enhancing the airtightness of the cylinder 10. The side surface of the gasket 30 is positioned in the radial direction of the cylinder 10 closer to the piston 15 than the inner circumferential surface 22 of the stepped portion 20.

[0035] like Figure 1 As shown, the ring member 40 is disposed in the stepped portion 20. Specifically, the ring member 40 is fitted into the stepped portion 20. The ring member 40 is formed in a cylindrical shape and covers the circumference of the piston 15 located at top dead center. The ring member 40 is made of metal. Here, the ring member 40 is made of the same material as the cylinder 10, but is not limited to this, and may be made of a different material than the cylinder 10. Furthermore, the ring member 40 is made of a material harder than the material of the washer 30.

[0036] The inner circumferential surface 41 of the ring member 40 faces the outer circumferential surface 15a of the piston 15 located at the top dead center when separated from the piston 15 located at the top dead center. The outer circumferential surface 42 of the ring member 40 faces the inner circumferential surface 22 of the stepped portion 20 when separated from the inner circumferential surface 22 of the stepped portion 20. The lower surface of the ring member 40 is in contact with the bottom surface of the stepped portion 20.

[0037] The ring member 40 is configured to narrow the space between the cylinder 10 and the piston 15. Specifically, the inner circumferential surface 41 of the ring member 40 is positioned closer to the outer circumferential surface 15a of the piston 15 than the inner circumferential surface 11 of the cylinder 10. Without the ring member 40, the space between the inner circumferential surface 11 of the cylinder 10 and the outer circumferential surface 15a of the piston 15 would ultimately be unused space for combustion, thus reducing combustion efficiency. On the other hand, by configuring the ring member 40 as in this embodiment, the unused space can be reduced, thereby increasing the compression ratio and improving fuel efficiency.

[0038] like Figure 1 As shown, the ring member 40 has a protruding portion 45. The protruding portion 45 is formed such that it protrudes from the ring member 40. Specifically, the protruding portion 45 protrudes from the upper surface of the ring member 40. The protruding portion 45 engages with the lower surface 31 of the washer 30. Specifically, the edge 45a of the tip of the protruding portion 45 engages with the lower surface 31 of the washer 30. Because the protruding portion 45 engages with the lower surface 31 of the washer 30, the ring member 40 can be prevented from moving due to vibration.

[0039] The protrusion 45 is formed in a ring shape along the circumferential direction on the upper part of the ring member 40. Therefore, the protrusion 45 engages with the lower surface 31 of the washer 30 over a wide area. However, this disclosure is not limited to this, and the protrusion 45 may be partially formed on the upper surface of the ring member 40. For example, a plurality of protrusions 45 may be formed at predetermined intervals in the circumferential direction on the upper surface of the ring member 40. Furthermore, a plurality of protrusions 45 may be formed at predetermined intervals in the radial direction of the ring member 40 on the upper surface of the ring member 40. In this case, since the protrusion 45 partially engages with the lower surface 31, a strong engagement force is likely to be generated relative to the lower surface 31 of the washer 30.

[0040] and Figure 2 Compared to the comparative example shown, the benefits of providing a protruding portion 45 on the ring member 40 will be described in detail.

[0041] Figure 2 This is a schematic diagram showing an internal combustion engine 100 according to a comparative example. In the comparative example, Figure 1 The protrusion 45 shown is not provided to the ring member 140. The upper surface of the ring member 140 does not contact the lower surface 31 of the washer 30. In this case, since the ring member 140 is only fitted into the stepped portion 20, the ring member 140 may move due to vibrations during operation of the internal combustion engine 100. For example, when the ring member 140 is in Figure 2When the ring member 140 moves in the direction indicated by the middle arrow, the inner circumferential surface 141 of the ring member 140 will contact the outer circumferential surface 15a of the piston 15. When the ring member 140 contacts the piston 15, at least one of the ring member 140 or the piston 15 may be damaged.

[0042] On the other hand, in this embodiment, since the protruding portion 45 of the ring member 40 engages with the lower surface 31 of the washer 30, even if the internal combustion engine 1 vibrates, the ring member 40 can be prevented from moving due to vibration. In particular, since the edge 45a of the protruding portion 45 engages with the lower surface 31, the ring member 40 can be prevented from moving due to vibration. As a result, since the inner circumferential surface 41 of the ring member 40 does not contact the outer circumferential surface 15a of the piston 15, damage to the ring member 40 and the piston 15 can be prevented.

[0043] <Modification Example>

[0044] Figure 3 This is a schematic diagram illustrating an improved example of internal combustion engine 1. Figure 3 The diagram shows only a portion of the internal combustion engine 1, and other components have been omitted for ease of explanation.

[0045] Piston 15 is eccentric due to thermal expansion. Specifically, as follows: Figure 3 As shown, when the piston 15 is observed in a plane, the outer peripheral surface 15a of the piston 15 is elliptical.

[0046] In the improved example, when the ring member 40 is viewed in a plane, its outer circumferential surface 42 is a true circle, while its inner circumferential surface 41 is an ellipse. Therefore, the width of the ring member 40 is not constant in the circumferential direction. The distance between the inner circumferential surface 41 and the outer circumferential surface 15a is constant throughout the entire circumference in the circumferential direction. In this case, the distance between the inner circumferential surface 41 and the outer circumferential surface 15a can be reduced compared to the case where the inner circumferential surface 41 is a true circle.

[0047] Figure 4 This is a schematic diagram showing an internal combustion engine 100 according to a comparative example. In the comparative example, the outer peripheral surface 115a of the piston 115 is elliptical, while the inner peripheral surface 141 and outer peripheral surface 142 of the ring member 140 are true circles. Therefore, as Figure 4 As shown, the gap between the outer peripheral surface 115a and the inner peripheral surface 141 is not constant, and there is a mixture of large gap and small gap portions.

[0048] On the other hand, in the improved example, since the inner circumferential surface 41 of the ring member 40 is elliptical in a manner similar to the outer circumferential surface 15a of the piston 15, the distance between the inner circumferential surface 41 and the outer circumferential surface 15a can be reduced throughout the entire circumference in the circumferential direction. Therefore, compared to the gap in the comparative example, the gap between the inner circumferential surface 41 and the outer circumferential surface 15a becomes smaller, and the significance of providing the ring member 40 described above (reducing the useless space between the cylinder 10 and the piston 15 to prevent a decrease in combustion efficiency) is effectively achieved.

[0049] Furthermore, in the improved examples, such as Figure 3 As shown, the ring member 40 has a protruding portion 48 that projects outward from the outer peripheral surface 42 in the radial direction. The protruding portion 48 is formed along the axial direction of the ring member 40. For example, the protruding portion 48 is formed from one end of the ring member 40 in the axial direction to the other end. On the other hand, a recessed portion 23 is formed on the inner peripheral surface 22 of the stepped portion 20, and the protruding portion 48 is fitted into the recessed portion 23. Therefore, even if the ring member 40 attempts to rotate in the circumferential direction during the operation of the internal combustion engine 1, the protruding portion 48 and the recessed portion 23 cooperate with each other to act as rotation stops. Figure 4 A protruding portion 48 and a recessed portion 23 are provided, but this disclosure is not limited thereto, and multiple protruding portions 48 and multiple recessed portions 23 may be provided. Although in Figure 4 Not shown in the figure, but in the improved example, the protrusion 45 described above is also formed on the ring member 40.

[0050] <Effects of this implementation method>

[0051] The internal combustion engine 1 of the embodiments described above includes a ring member 40 having a cylindrical shape, the ring member 40 being disposed at a stepped portion 20 formed at the upper end of the inner peripheral surface 11 of the cylinder 10. The ring member 40 is provided with a protruding portion 45, the protruding portion 45 protruding in such a way that the protruding portion 45 engages with the lower surface 31 of the washer 30.

[0052] Because the protruding portion 45 of the ring member 40 engages with the lower surface 31 of the washer 30, the ring member 40 can be prevented from moving due to vibration even if the internal combustion engine 1 vibrates. As a result, since the inner circumferential surface 41 of the ring member 40 does not contact the outer circumferential surface 15a of the piston 15, damage to the ring member 40 and the piston 15 can be prevented.

[0053] This disclosure has been described based on exemplary embodiments. The technical scope of this disclosure is not limited to the scope described in the above embodiments, and various changes and modifications can be made within the scope of this disclosure. For example, all or part of the device may be configured with any functionally or physically distributed or integrated units. Furthermore, new exemplary embodiments resulting from any combination of the above embodiments are included in the exemplary embodiments. Moreover, the effects of the new exemplary embodiments resulting from the combination also have the effects of the original exemplary embodiments.

[0054] Description of reference numerals in the attached figures

[0055] 1. Internal Combustion Engine

[0056] 10 cylinders

[0057] 11 Inner peripheral surface

[0058] 15 Pistons

[0059] 15a Outer peripheral surface

[0060] 20 steps

[0061] 23. Recessed portion

[0062] 25 Cylinder head

[0063] 30 Washer

[0064] 31 Lower surface

[0065] 40 ring components

[0066] 41 Inner peripheral surface

[0067] 45. Protruding part

[0068] 45a edge

[0069] 48. Protruding part

Claims

1. An internal combustion engine, comprising: Cylinder, in which the piston reciprocates; Cylinder head, located above the cylinder; A gasket is disposed between the cylinder and the cylinder head; The stepped portion is formed at the upper end of the inner circumferential surface of the cylinder and located below the washer; A ring member, disposed on the stepped portion, has a cylindrical shape; as well as The protruding portion is formed in such a way that it protrudes from the ring member and engages with the lower surface of the washer. The edge of the tip of the protrusion engages with the lower surface of the washer. When the piston is viewed in a plane, its outer peripheral surface is elliptical. The inner circumferential surface of the ring member facing the outer circumferential surface is elliptical, such that when the ring member is viewed in a plane, the inner circumferential surface of the ring member is separated from the outer circumferential surface by a predetermined distance. The ring member has a protruding portion that projects outward from the outer peripheral surface of the ring member in the radial direction. A recessed portion is formed on the inner circumferential surface of the stepped portion, and the protruding portion is fitted into the recessed portion. The protruding portion is formed from one end of the ring member in the axial direction to the other end.

2. The internal combustion engine according to claim 1, wherein, The side surface of the gasket is positioned closer to the piston in the radial direction of the cylinder than the inner circumferential surface of the stepped portion. The protruding portion protrudes from the upper surface of the ring member.

3. The internal combustion engine according to claim 1, wherein, The protruding portion is formed into a ring shape along the circumferential direction on the upper part of the ring member.

4. The internal combustion engine according to claim 2, wherein, On the upper surface of the ring member, a plurality of protrusions are formed at predetermined intervals in the circumferential direction.

5. The internal combustion engine according to claim 2, wherein, On the upper surface of the ring member, a plurality of protrusions are formed at predetermined intervals in the radial direction.

6. The internal combustion engine according to claim 1, wherein, When the ring member is viewed in a plane, its outer peripheral surface is a true circle.

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