Passage structure of internal combustion engine

Abstract

To provide a passage structure of an internal combustion engine capable of suppressing pulsation of fluid.SOLUTION: A passage structure of an internal combustion engine includes a first main passage extending from a pump that pumps a fluid circulating in the internal combustion engine, a second main passage extending in a direction intersecting the first main passage, and a protruding portion provided in the first main passage. The second main passage is connected to the connecting portion, the connecting portion extends in a direction intersecting a flow direction of the fluid flowing through the first main passage, has a wall against which the fluid hits, and the protruding portion is located upstream of the wall and protrudes in a direction intersecting the extending direction of the first main passage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a passage structure for an internal combustion engine. [Background technology]

[0002] Conventionally, a passage structure for an internal combustion engine through which oil flows in the internal combustion engine is known (see, for example, Patent Document 1). The passage structure for an internal combustion engine in Patent Document 1 includes a passage through which oil discharged from a pump passes and which extends to a discharge port, and a passage that extends in the longitudinal direction of the internal combustion engine so as to intersect with the passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-107036 Summary of the Invention [Problem to be solved by the invention]

[0004] In the internal combustion engine of Patent Document 1, the oil (fluid) discharged from the pump may collide with the wall of the discharge port, causing oil pulsation, which may cause the wall of the oil passage to vibrate and generate abnormal noise.

[0005] An object of the present disclosure is to provide a passage structure for an internal combustion engine that can suppress fluid pulsation. [Means for solving the problem]

[0006] A passage structure of an internal combustion engine according to the present disclosure is a passage structure of an internal combustion engine through which a fluid circulating in the internal combustion engine passes, the passage structure comprising: a first main passage extending from a pump that pressurizes the fluid; a second main passage extending in a direction intersecting the first main passage; and a protrusion provided in the first main passage, wherein the first main passage has a connection portion formed at an end of the first main passage, the second main passage is connected to the connection portion, the connection portion extends in a direction intersecting the flow direction of the fluid flowing through the first main passage and has a wall against which the fluid hits, and the protrusion is located upstream of the wall and protrudes in a direction intersecting the extension direction of the first main passage. [Effects of the Invention]

[0007] According to this passage structure for an internal combustion engine, the protrusion located upstream of the wall absorbs pressure waves of the fluid that hit the wall and bounce back, thereby suppressing fluid pulsation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a passageway design for an internal combustion engine according to one embodiment of the present disclosure; [Figure 2] 1 is a rear perspective view of a passageway arrangement for an internal combustion engine according to one embodiment of the present disclosure; [Figure 3] FIG. 2 is a front view of a pump cover according to one embodiment of the present disclosure. [Figure 4] 2 is an enlarged view of a passageway structure of an internal combustion engine according to one embodiment of the present disclosure; DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described below with reference to the drawings. In the following description, the side of the damper pulley 4 (crank pulley) of the internal combustion engine E will be referred to as the front side, and the opposite side will be referred to as the rear side. In the drawings, the front side will be referred to as FS, the rear side as BS, the right side as RS, the left side as LS, the upper side as US, and the lower side as DS. In this embodiment, left and right correspond to the left and right when a user looks at the front side from the rear side.

[0010] As shown in FIG. 1 , the internal combustion engine E has a crankshaft 2, a damper pulley 4, a cover 6, a transmission member 8, a camshaft 10, a pump 12, and a pump cover 14. The crankshaft 2 extends in the front-to-rear direction of the internal combustion engine E. The damper pulley 4 is fixed to the front end of the crankshaft 2. The transmission member 8 transmits the rotation of the crankshaft 2 to the camshaft 10. In this embodiment, the transmission member 8 is a timing chain. However, the transmission member 8 may also be a timing belt.

[0011] The cover 6 covers the transmission member 8. As shown in FIG. 2, the pump cover 14 is fixed to the rear surface of the cover 6. In this embodiment, the cover 6 is a metal member such as aluminum die-cast. The pump 12 is provided at a position sandwiched between the cover 6 and the pump cover 14. In this embodiment, the pump cover 14 is a metal member such as a sheet metal member or aluminum die-cast. The pump cover 14 is fixed to the cover 6 with bolts or the like. In this embodiment, the pump 12 is a trochoid oil pump having an outer rotor and an inner rotor. The inner rotor is driven by the crankshaft 2 (see FIG. 1).

[0012] 1, the passage structure 1 includes a first main passage 21, a second main passage 22, a sub-passage 23, an on-off valve 24, and a protrusion 25. The passage structure 1 of the internal combustion engine E is formed in a space sandwiched between a cover 6 and a pump cover 14.

[0013] The first main passage 21 extends from the discharge side of the pump 12. As shown in FIGS. 3 and 4, specifically, the first main passage 21 extends diagonally downward to the left from the pump 12 and is formed by being surrounded by the cover 6 (see FIGS. 1 and 2) and the pump cover 14. As shown by the arrow labeled OUT in FIG. 3, the fluid discharged from the pump 12 first passes through the first main passage 21. Note that, as shown by the arrow labeled IN in FIG. 3, the fluid is supplied to the pump 12 via a supply passage 26. In this embodiment, the fluid is oil circulating through the internal combustion engine E. However, the fluid may be a refrigerant circulating through the internal combustion engine E, for example.

[0014] As shown in FIGS. 1 and 4, the first main passage 21 has a connection portion 21a. The connection portion 21a is a space formed below the first main passage 21, i.e., at the downstream end in the fluid flow direction. As shown in FIGS. 3 and 4, the connection portion 21a includes a wall 21b. In this embodiment, the wall 21b forms the lower end of the connection portion 21a and extends in a direction intersecting with the first main passage 21. In other words, the wall 21b extends in a direction intersecting with the fluid flow direction in the first main passage 21. Therefore, the fluid flowing through the first main passage 21 hits the wall 21b. In this embodiment, the wall 21b extends in the front-to-rear direction of the internal combustion engine E.

[0015] The second main passage 22 extends in a direction intersecting with the first main passage 21. The second main passage 22 is connected to the connecting portion 21a. In this embodiment, the second main passage 22 extends rearward from the connecting portion 21a in the front-rear direction. That is, the second main passage 22 protrudes rearward from the rear surface of the first main passage 21. In this embodiment, a portion of the wall of the second main passage 22 is formed continuously with the wall 21b. As shown in FIG. 4 , the diameter D1 of the upstream portion 22a located on the connecting portion 21a side of the second main passage 22 is smaller than the diameter D2 of the downstream portion 22b located downstream of the upstream portion 22a. The diameter gradually decreases from the diameter D1 to the diameter D2 from the upstream portion 22a to the downstream portion 22b. In this way, by making the diameter D2 of the second main passage 22 smaller than the diameter D1, the generation of fluid pulsation can be suppressed. In this embodiment, the diameter is gradually reduced from the diameter D1 to the diameter D2, but the diameter may be reduced in a stepwise manner from the diameter D1 to the diameter D2.

[0016] 1 and 3, the sub-passage 23 extends from the connecting portion 21a. In this embodiment, the sub-passage 23 extends diagonally downward to the right from the connecting portion 21a. In this embodiment, the sub-passage 23 is provided in the wall 21b.

[0017] The on-off valve 24 is disposed in the bypass passage 23 and opens and closes the bypass passage 23. The on-off valve 24 in this embodiment is a relief valve that opens when the pressure of the fluid flowing through the bypass passage 23 reaches or exceeds a certain value, and allows the fluid to pass through the bypass passage 23 and be discharged.

[0018] As shown in Fig. 4, the protrusion 25 is provided in the first main passage 21. In this embodiment, the protrusion 25 is formed on the cover 6. More specifically, the protrusion 25 is formed by the cover 6 protruding in a direction intersecting the extension direction of the first main passage 21. In this embodiment, the protrusion 25 is formed by the cover 6 protruding forward. The protrusion 25 is located upstream of the wall 21b with respect to the flow direction of the fluid discharged from the pump 12.

[0019] Furthermore, in this embodiment, the protrusion 25 protrudes from the connection portion 21a in a direction intersecting with the first main passage 21. More specifically, the cover 6, which is located in front of the connection portion 21a, protrudes in the forward direction, which is opposite to the direction in which the second main passage 22 extends (the rearward direction in this embodiment), thereby forming the protrusion 25. In other words, the protrusion 25 is provided opposite the second main passage 22 in the front-rear direction. By forming the protrusion 25 in such a position, for example, when no pulsation is occurring, the fluid is less likely to flow into the protrusion 25. This makes it possible to suppress the passage resistance generated by the fluid flowing through the first main passage 21.

[0020] Furthermore, the diameter D3 of the protrusion 25 is larger than the diameter D1 of the second main passage 22. Furthermore, in this embodiment, the protrusion 25 is provided so that the cross section of the protrusion 25 and the cross section of the second main passage 22 overlap in the front-to-rear direction. Of the fluid that hits the wall 21b, the fluid that does not flow into the second main passage 22 enters the protrusion 25. That is, when the fluid that flows through the first main passage 21 turns at the connecting portion 21a and flows into the second main passage 22, the fluid that bounces back toward the rear surface of the first main passage 21 flows into the protrusion 25. Because the diameter D3 of the protrusion 25 is larger than the diameter D1 of the second main passage 22 and the cross sections of the protrusion 25 and the second main passage 22 overlap in the front-to-rear direction, the fluid that does not flow into the second main passage 22 easily flows into the protrusion 25. This makes it easier to suppress fluid pulsation.

[0021] The thickness T1 of the wall 25b forming the bottom 25a (front surface) of the protrusion 25 is thinner than the thickness T2 of the portion different from the bottom 25a. In this embodiment, the thickness of the cover 6 is thinner only at the bottom 25a. That is, the thickness of the bottom 25a of the protrusion 25 is thinner than the thickness of the wall portion forming the first main passage 21. By making the thickness T1 of the bottom 25a thinner than the thickness T2 in this way, the bottom 25a is more likely to deform and absorb fluid pulsation. Furthermore, since the protrusion 25 is formed on the cover 6, the thickness T1 of the bottom 25a can be changed by changing the plate thickness of the cover 6, making it easy to adjust the thickness T1.

[0022] In the passage structure 1 of the internal combustion engine E formed in this manner, the fluid discharged from the pump 12 enters the connecting portion 21a and hits the wall 21b. A portion of the fluid that hits the wall 21b flows into the second main passage 22, while the remaining fluid enters the protruding portion 25. This makes it possible to reduce the amount of fluid that hits the wall 21b and is reflected. As a result, it is possible to suppress fluid pulsation.

[0023] Furthermore, a secondary passage 23 extends from the connecting portion 21a, and an on-off valve 24 is provided in the secondary passage 23. In this embodiment, the protruding portion 25 is disposed in front of the connecting portion 21a, and the secondary passage 23 extends from the connecting portion 21a. Therefore, the on-off valve 24 and the protruding portion 25 are provided close to each other. This allows the protruding portion 25 to absorb pulsations generated by the opening and closing of the on-off valve 24. As a result, it is easier to suppress the generation of pulsations.

[0024] As described above, according to the present disclosure, it is possible to provide a passage structure for an internal combustion engine that can suppress fluid pulsation.

[0025] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0026] In the above embodiment, an example has been described in which the first main passage 21 extends diagonally downward to the left from the pump 12, but the present disclosure is not limited to this. The first main passage 21 may be any passage that extends from the pump 12, and the direction in which it extends may be changed as appropriate.

[0027] In addition, in the above embodiment, an example in which the second main passage 22 extends toward the rear side has been described, but the present disclosure is not limited to this. The second main passage 22 may extend in any direction intersecting with the first main passage 21, and the extending direction may be changed as appropriate.

[0028] In the above embodiment, the sub-passage 23 extends diagonally downward to the right from the connecting portion 21a, but the present disclosure is not limited to this. The sub-passage 23 may extend in any direction from the connecting portion 21a. [Explanation of symbols]

[0029] 1: Passage structure, 2: Crankshaft, 6: Cover 8: Transmission member, 10: Camshaft 12: Pump, 14: Pump cover 21: first main passage, 21a: connection part, 21b: wall 22: Second main passage, 22a: Upstream section, 22b: Downstream section 23: Sub-passage, 24: On-off valve 25: Protrusion, 25a: Bottom, 25b: Wall E: Internal combustion engine T1: Thickness, T2: Thickness

Claims

1. A passage structure of an internal combustion engine through which a fluid circulating in the internal combustion engine passes, a first main passage extending from a pump that pumps the fluid; a second main passage extending in a direction intersecting the first main passage; a protrusion provided in the first main passage; Equipped with the first main passage has a connection portion formed at an end of the first main passage, the second main passage is connected to the connection portion, the connecting portion extends in a direction intersecting a flow direction of the fluid flowing through the first main passage and has a wall against which the fluid hits, the protruding portion is located upstream of the wall and protrudes in a direction intersecting with the direction in which the first main passage extends. Passage structure of an internal combustion engine.

2. a secondary passage extending from the connection portion; an on-off valve disposed in the sub-passage and configured to open and close the sub-passage; Furthermore, The protruding portion protrudes from the connecting portion in a direction intersecting with the first main passage.

2. A passage structure for an internal combustion engine according to claim 1.

3. The protruding portion protrudes in a direction opposite to an extension direction of the second main passage.

2. A passage structure for an internal combustion engine according to claim 1.

4. The diameter of the protrusion is larger than the diameter of the second main passage.

2. A passage structure for an internal combustion engine according to claim 1.

5. The second main passage has a smaller diameter at a downstream portion located downstream of the upstream portion than at an upstream portion located on the connection portion side.

2. A passage structure for an internal combustion engine according to claim 1.

6. The thickness of the bottom of the protrusion is thinner than the thickness of the portion different from the bottom.

2. A passage structure for an internal combustion engine according to claim 1.

7. the internal combustion engine includes a crankshaft, a camshaft, a transmission member that transmits rotation of the crankshaft to the camshaft, and a cover that covers the transmission member; the pump is disposed at a position sandwiched between the cover and a pump cover attached to the cover, and the protrusion is formed on the cover. A passage structure for an internal combustion engine according to any one of claims 1 to 6.

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