Blow-by gas treatment device and engine

Abstract

To provide a blow-by gas treatment device and an engine capable of effectively separating an oil component and a gas component contained in blow-by gas.SOLUTION: The blow-by gas processing device 10 includes a breather chamber 30 communicating with the ports 51 respectively close to one side in the front-rear direction and one side in the left-right direction in the crankcase 5 and accommodating the blow-by gas discharged from the ports 51, a breather device 20 attached to the breather chamber 30 and having an introduction port 211 taking the blow-by gas into the internal space 210, a discharge port 212 discharging the oil component separated from the blow-by gas, and a delivery channel portion 23 delivering the gas component separated from the blow-by gas upward, and a recirculation pipe 50 provided between the delivery channel portion 23 and the introduction port 67 close to the other side in the front-rear direction of the intake manifold 6 and returning the gas component from the introduction port 67 to the intake manifold 6.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a blow-by gas treatment device and an engine equipped with the blow-by gas treatment device. [Background technology]

[0002] The breather device attached to the engine separates the oil and gas components from the blow-by gas, then returns the gas components to the combustion chamber via passages and the intake system, where they are burned in the combustion chamber to make them harmless before being released into the atmosphere.

[0003] Patent Document 1 discloses a blow-by gas recirculation device that improves gas-liquid separation performance without increasing the size of an oil separator. This blow-by gas recirculation device includes an intake manifold attached to one side of an engine and configured to introduce intake air into a combustion chamber, an oil separator provided on a side surface of a cylinder block on one side of the engine and configured to separate gas and liquid in blow-by gas, a communication part configured to communicate a blow-by gas outlet of the oil separator with the intake manifold, and a PCV valve configured to adjust the flow rate of the blow-by gas introduced into the intake manifold through the communication part, the PCV valve is attached to the intake manifold, the communication part is connected to the PCV valve, and the attachment position of the PCV valve relative to the intake manifold is located above the blow-by gas outlet of the oil separator when the engine is installed in a vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-101591 Summary of the Invention [Problem to be solved by the invention]

[0005] Blow-by gas is gas that flows into the crankcase through the gap between the piston and cylinder of the engine and contains unburned and burned gas components and oil components (e.g., oil mist). It is desirable for the breather device to separate the oil and gas components of the blow-by gas as much as possible along the path that sends the blow-by gas from the crankcase to the head cover.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a blow-by gas treatment device and an engine that can effectively separate the oil components and gas components contained in blow-by gas. [Means for solving the problem]

[0007] One aspect of the present invention is a blow-by gas treatment device that treats blow-by gas sent to a crankcase located below a cylinder block and returns it to an intake manifold located above the cylinder block, the blow-by gas treatment device comprising: a breather chamber that communicates with ports that are proximal to one front-rear side and one left-right side of the crankcase and that accommodates the blow-by gas discharged from the ports; an inlet port that is attached to the breather chamber and that takes the blow-by gas accommodated in the breather chamber into an internal space; an outlet port that discharges oil components separated from the blow-by gas; and a return pipe that is provided between the delivery passage and an inlet port that is proximal to the other front-rear side of the intake manifold and that returns the gas components discharged from above the breather device from the inlet port to the intake manifold.

[0008] Another aspect of the present invention is an engine having a recirculation path that treats and returns blow-by gas from the crankcase to the intake manifold, in which the above-mentioned blow-by gas treatment device is provided in the recirculation path. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a blow-by gas treatment device and an engine that can effectively separate oil components and gas components contained in blow-by gas. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view illustrating an engine equipped with a breather device according to an embodiment of the present invention; [Figure 2] 1 is a perspective view illustrating an engine equipped with a breather device according to an embodiment of the present invention; [Figure 3] 1 is a cross-sectional view illustrating an example of an engine equipped with a breather device according to an embodiment of the present invention. [Figure 4] 1 is a perspective view illustrating a blow-by gas treatment device according to an embodiment of the present invention; [Figure 5] 2 is a perspective view illustrating a fresh air introduction section in the blow-by gas treatment device according to the embodiment; FIG. [Figure 6] 1 is a partial cross-sectional view of an engine to which a breather device according to an embodiment of the present invention is attached. [Figure 7] 1 is a perspective view illustrating a breather device according to an embodiment of the present invention; [Figure 8] 1 is a cross-sectional view illustrating a breather device according to an embodiment of the present invention. [Figure 9] 1 is a perspective view illustrating a state in which a cover body is removed from the blade device according to the present embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will now be described with reference to the drawings. The embodiments described below are preferred examples of the present invention, and therefore various technically preferable limitations are applied thereto, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is particularly limited. Furthermore, in each drawing, similar components are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0012] (engine) 1 and 2 are perspective views illustrating an engine equipped with a breather device according to this embodiment. FIG. 3 is a cross-sectional view illustrating an engine equipped with the breather device according to this embodiment. In this embodiment, the direction of the crankshaft of the engine 1 is referred to as the X direction (front-rear direction), the left-right direction of the engine 1 (one of the directions perpendicular to the crankshaft) is referred to as the Y direction (left-right direction), and the height direction of the engine 1 (direction perpendicular to the X and Y directions) is referred to as the Z direction (up-down direction). Fig. 1 shows a perspective view of the engine 1 as seen from diagonally above the front right, and Fig. 2 shows a perspective view of the engine 1 as seen from diagonally above the rear left. Fig. 3 shows a cross-sectional view of the engine 1 cut along the YZ plane at the position of the breather device 20 in the fore-and-aft direction. In Fig. 3, the cross-sectional portion is shown painted black.

[0013] 1 and 2 is an internal combustion engine, such as a diesel engine, and is mounted on industrial machinery such as vehicles, construction machinery, and agricultural machinery. The engine 1 includes a cylinder head 2, a head cover 3, a cylinder block 4, a crankcase 5, an intake manifold 6, an exhaust manifold 7, a fuel injection device 8, and a blow-by gas treatment device 10. The blow-by gas treatment device 10 includes a breather device 20.

[0014] The cylinder head 2 of the engine 1 is, for example, the cylinder head of a multi-cylinder engine having multiple cylinders. A head cover 3 is mounted on top of the cylinder head 2. The internal space of the head cover 3 is closed. A cylinder block 4 is provided between the cylinder head 2 and a crankcase 5 and includes a cylinder 40 in which a piston 41 reciprocates.

[0015] The intake manifold 6 is an example of an intake distribution means that distributes intake air to each cylinder of the engine 1. The exhaust manifold 7 is an example of an exhaust collection means that collects exhaust from each cylinder of the engine 1. The blow-by gas treatment device 10 separates oil components and gas components from the blow-by gas that has flowed into the crankcase 5 of the engine 1 and returns the separated components to the intake manifold 6.

[0016] The blow-by gas treatment device 10 is provided in a return path that treats and returns blow-by gas from the crankcase 5 to the intake manifold 6. Details of the blow-by gas treatment device 10 will be described later. The breather device 20 is provided in the passageway through which blow-by gas passes in the blow-by gas treatment device 10. The blow-by gas that flows into the crankcase 5 is sent from the crankcase 5 to the breather device 20, where it is separated into oil and gas components. The breather device 20 returns the oil component separated from the blow-by gas to the crankcase 5 and sends the gas component to the intake manifold 6.

[0017] (Blow-by gas treatment device) FIG. 4 is a perspective view illustrating the blow-by gas treatment device according to the present embodiment. FIG. 5 is a perspective view illustrating an example of a fresh air introduction section in the blow-by gas treatment device according to this embodiment. FIG. 6 is a partial cross-sectional view of an engine to which the breather device according to this embodiment is attached. 6 shows a cross-sectional view taken along the XZ plane at the position of the breather device 20 in the left-right direction of the engine 1. In FIG. 6, the cross-sectional portion is shown painted black. In describing the blow-by gas treatment device 10 according to this embodiment, for configurations not shown in FIGS. 4 to 6, reference will be made to FIGS. 1 to 3 as appropriate unless otherwise specified.

[0018] The engine 1 has a recirculation path that processes and returns blow-by gas from the crankcase 5 to the intake manifold 6. In the engine 1 according to this embodiment, as shown in Fig. 4, the recirculation path for blow-by gas is provided outside the cylinder block 4 from diagonally above one side (e.g., toward the front) of the crankcase 5 in the fore-and-aft direction to the other side (e.g., toward the rear) of the intake manifold 6 provided above the cylinder block 4 in the fore-and-aft direction.

[0019] The blow-by gas treatment device 10 according to this embodiment is provided in the return path of this blow-by gas, and separates the oil components and gas components of the blow-by gas sent to the crankcase 5 and returns the gas components to the intake manifold 6.

[0020] The blow-by gas treatment device 10 comprises a breezer chamber 30 for storing blow-by gas, a breezer device 20 attached to the breezer chamber 30, and a return pipe 50 for returning gas components separated from the blow-by gas from the breezer device 20 to the intake manifold 6.

[0021] The breather chamber 30 is disposed diagonally above and toward one side in the front-to-rear direction of the crankcase 5 (e.g., toward the front), and forms a space into which blow-by gas is introduced from the crankcase 5. The breather chamber 30 communicates with ports 51 that are proximal to one side in the front-to-rear direction (e.g., toward the front) and one side in the left-to-right direction (e.g., the right side) of the crankcase 5, and receives the blow-by gas discharged from the ports 51. The breather device 20 is attached to this breather chamber 30. The attachment of the breather device 20 to the breather chamber 30 will be described in detail later.

[0022] 6, the breather device 20 has an inlet 211 that takes in the blow-by gas contained in the breather chamber 30 into an internal space 210, an outlet 212 that discharges the oil component separated from the blow-by gas, and a delivery passage portion 23 that delivers the gas separated from the blow-by gas upward. Details of the breather device 20 will be described later.

[0023] The return pipe 50 is provided between the delivery passage 23 of the breather device 20 and an introduction port 67 located near the other side in the front-to-rear direction (for example, the rear side) of the intake manifold 6, and constitutes a part of the return path for returning the gas components delivered from above the breather device 20 from the introduction port 67 to the intake manifold 6. A flow rate adjustment valve (PCV valve) 26 is attached between the delivery passage 23 of the breather device 20 and the return pipe 50.

[0024] The breather chamber 30, which houses the breather device 20, and the return pipe 50 are disposed in a space diagonally above the crankcase 5. As shown in FIG. 3, the intake manifold 6 of the engine 1 according to this embodiment has an upper pipe section 61 and a lower pipe section 62 that extends diagonally downward from the upper pipe section 61 toward the piston valve 42. The injector 81 of the fuel injection device 8 is connected to the outside of the lower pipe section 62 along an extension of the direction in which the lower pipe section 62 extends. In this embodiment, the injector 81 is attached at an angle of approximately 20° with respect to the horizontal, so that it extends diagonally downward from the outside toward the inside in the left-right direction. This increases the amount of fuel injected from the injector 81 that is injected directly toward the piston valve 42.

[0025] If the injector 81 were installed horizontally, most of the fuel injected from the injector 81 would collide with the inner wall of the lower pipe section 62 before heading toward the piston valve 42. By installing the injector 81 at an angle downward as in this embodiment, most of the fuel injected from the injector 81 is sent directly toward the piston valve 42 without colliding with the inner wall of the lower pipe section 62, enabling efficient combustion.

[0026] As described above, by mounting the injector 81 at an angle diagonally downward on the outside of the lower pipe portion 62, more space is created below the injector 81 than when the injector 81 is mounted horizontally. In the engine 1 according to this embodiment, the breather chamber 30 that houses the breather device 20 and the return pipe 50 are arranged in the space created by mounting the injector 81 at an angle diagonally downward. This makes it possible to effectively utilize the space created by mounting the injector 81 at an angle.

[0027] The blow-by gas processing device 10 may include a fresh air delivery pipe 60. For example, as shown in FIG. 5 , one end 60a of the fresh air delivery pipe 60 is connected to an intake section 65 that delivers fresh intake air to the intake manifold 6, and the other end 60b is connected to the cylinder head cover 3. The other end 60b of the fresh air delivery pipe 60 is connected to a position away from the port 51 and the breather chamber 30 in the front-rear direction of the cylinder head cover 3. The fresh air delivered from the fresh air delivery pipe 60 to the cylinder head cover 3 passes from the cylinder head cover 3 through the inner wall of the cylinder block 4 (for example, the insertion space of the push rod) and is sent to the crankcase 5. Since the other end 60b of the fresh air delivery pipe 60 is connected to a position away from the port 51 and the breather chamber 30 in the front-rear direction of the cylinder head cover 3, the fresh air delivered from the fresh air delivery pipe 60 is delivered to the crankcase 5 from a position away from the port 51 and the breather chamber 30. As a result, fresh air is sent from a position away from the port 51 of the crankcase 5 toward the port 51 over a wide area of ​​the crankcase 5, and the blow-by gas in the crankcase 5 can be sent toward the port 51 without waste.

[0028] (Breather device) FIG. 7 is a perspective view illustrating the breather device according to the present embodiment. FIG. 8 is a cross-sectional view illustrating the breather device according to this embodiment. As shown in FIGS. 7 and 8, a breather device 20 according to this embodiment includes a main body case 21, an inclined surface 22, and a delivery flow path portion .

[0029] The main body case 21 has an internal space 210 that accommodates blow-by gas. The main body case 21 also has an inlet 211 for blow-by gas and an outlet 212 that discharges the separated oil components from the internal space 210 to the outside. The opening area of ​​the inlet 211 is preferably larger than the opening area of ​​the outlet 212. This makes it easier to take in the blow-by gas from the inlet 211 before separation.

[0030] For example, the main body case 21 is provided in a box-like shape having an opening 21h, and a portion of the opening 21h is closed by the lid 24. Because the area of ​​the lid 24 is smaller than the area of ​​the opening 21h, by opening and attaching one end and the other end of the lid 24, an inlet 211 is formed in the gap between the opening 21h and one end of the lid 24, and an outlet 212 is formed in the gap between the opening 21h and the other end of the lid 24. The sizes of the inlet 211 and the outlet 212 can be adjusted by adjusting the area of ​​the lid 24 and the attachment position relative to the opening 21h. Note that, although the main body case 21 and the lid 24 are separate bodies in this embodiment, the main body case 21 and the lid 24 may be integrated.

[0031] The inclined surface 22 is provided inside the main body case 21, and is provided so as to slope downward from the side of the inlet 211 toward the side of the outlet 212. For example, the inclined surface 22 is provided so as to slope from a position facing the inlet 211 inside the main body case 21 toward the outlet 212. As a result, the outlet 212 is provided below the inclined surface 22. In this embodiment, a part of the exterior of the main body case 21 is the inclined plate 21a, and the inclined surface 22 is configured on a surface included in the inclined plate 21a (the surface of the inclined plate 21a facing the internal space 210).

[0032] The inclined surface 22 may not be part of the exterior of the main body case 21, but may be disposed as a separate member within the internal space 210. The inclined surface 22 may slope downward from front to rear, or from rear to front. The inclination direction of the inclined surface 22 is not limited to the X direction (front-rear direction) and may also be the Y direction (left-right direction). The opening of the inlet 211 and the opening of the outlet 212 may be oriented in the same direction or different directions. For example, in the example shown in FIG. 3, both the inlet 211 and the outlet 212 are provided so as to face rearward, but the opening of the inlet 211 may be oriented so as to face rearward, and the opening of the outlet 212 may be oriented so as to face forward.

[0033] The delivery flow path section 23 is provided on the opposite side of the main body case 21 from the outlet 212, and is a flow path that delivers the separated gas components from the internal space 210 to the outside. In this embodiment, the delivery flow path section 23 is provided in a cylindrical shape that extends upward from the upper side of the main body case 21.

[0034] As a preferred example, the main body case 21 is formed in a right-angled trapezoidal shape in the cross-sectional view of Fig. 8, with its long and short sides parallel to each other and arranged in the vertical direction. An opening 21h of the main body case 21 is provided on the long side, and an inclined plate 21a is provided at a position corresponding to the oblique side between the short and long sides. An output flow path section 23 is provided at a position near the short side of the main body case 21, corresponding to the short side and a side perpendicular to the long side.

[0035] A flow rate adjustment valve 26 is attached to the delivery flow path section 23 extending upward from the main body case 21. The flow rate adjustment valve 26 is attached so as to extend forward from the delivery flow path section 23. The delivery flow path section 23 is disposed closer to one side in the front-to-rear direction (for example, the front side) of the upper part of the main body case 21. Therefore, by providing the flow rate adjustment valve 26 so as to extend to the other side in the front-to-rear direction (for example, the rear side), it is possible to effectively utilize the empty space above the main body case 21. A return pipe 50 is connected to the flow rate adjustment valve 26.

[0036] FIG. 9 is a perspective view illustrating a state in which the cover of the breather device according to the present embodiment is removed. The main body case 21 has extension portions 25 extending from the opening 21h toward the inside of the main body case 21. The extension portions 25 are provided in multiple locations. As an example, in this embodiment, three extension portions 25 are provided. When viewed from the front of the opening 21h, the arrangement of the multiple extension portions 25 is different from each other in the vertical and horizontal directions. In other words, adjacent extension portions 25 are arranged so as not to overlap each other in the vertical and horizontal directions. For example, of the three extension portions 25, the second extension portion 25 is arranged diagonally to the lower right of the first extension portion 25 from the top, and the third extension portion 25 is arranged diagonally to the lower left of the second extension portion 25. The lid 24 is fixed to the end of the extension portion 25 on the opening 21h side by, for example, crimping.

[0037] When adjacent extension portions 25 are arranged horizontally or vertically in the internal space 210 of the main body case 21, the passage (flow path) between them becomes narrow. However, by arranging them diagonally as described above, the passage (flow path) does not become narrow, and the path from the inlet 211 to the outlet 212 becomes non-linear (S-shaped), so that the internal space 210 can have a labyrinth structure.

[0038] (Installing the bladder device in the bladder chamber) As shown in Figure 6, a brazer chamber 30 that forms a space for introducing blow-by gas is provided diagonally above one side of the crankcase 5 in the front-to-rear direction (for example, toward the front). The brazer chamber 30 is in communication with the crankcase 5 via a port 51 provided in the crankcase 5. The brazer device 20 is inserted into the brazer chamber 30. For example, an opening is provided in the top of the brazer chamber 30, and the brazer device 20 is inserted into the inside of the brazer chamber 30 through this opening. With the opening of the brazer chamber 30 covered by a flange portion 21b (see Figure 7) provided on the brazer device 20, the brazer device 20 is fastened to the brazer chamber 30 by passing and fastening a mounting bolt 21d (see Figure 1) through a mounting hole 21c (see Figure 7) provided in the flange portion 21b.

[0039] The port 51 of the crankcase 5 is disposed below the breather chamber 30 and toward the front or rear (for example, toward the front). The inlet 211 of the breather device 20 is preferably provided distally from the port 51 of the crankcase 5 within the breather chamber 30. The opening of the port 51 preferably faces in a direction different from the direction of the inlet 211 of the breather device 20 attached to the breather chamber 30. For example, when the breather device 20 is attached to the breather chamber 30, the inlet 211 of the breather device 20 faces rearward. On the other hand, the opening of the port 51 faces in the left-right direction (for example, to the right).

[0040] 3, it is preferable that the breather device 20 is attached to the breather chamber 30 at a slight incline relative to the vertical direction. This makes it easier for oil components separated from the blow-by gas, which will be described later, to collect in the corners of the discharge port 212, allowing the oil components to be discharged from the discharge port 212 more effectively.

[0041] (Flow of blow-by gas) Next, the flow of blow-by gas will be described. Blow-by gas that has flowed into the crankcase 5 of the engine 1 is sent out from the port 51 to the breather chamber 30 when the piston 41 is pushed down, creating a positive pressure inside the crankcase 5. At this time, fresh air is sent from the fresh air delivery pipe 60 to the cylinder head 2, and is then sent to the crankcase 5 from the inside wall of the cylinder block 4 (for example, the space through which the push rod passes). The fresh air being sent into the crankcase 5 increases the internal pressure of the crankcase 5, and a pressure is applied to send the blow-by gas out from the port 51 to the breather chamber 30. The blow-by gas sent from the port 51 to the breather chamber 30 spreads inside the breather chamber 30 and flows into the internal space 210 of the main body case 21 from the inlet 211 of the breather device 20 provided in the breather chamber 30.

[0042] Of the blow-by gas that has flowed into the internal space 210 of the main body case 21, oil components with a high specific gravity are dropped downward along the inclined surface 22, while gas components with a low specific gravity proceed to the delivery flow path portion 23 above the main body case 21. The gas components that have proceeded to the delivery flow path portion 23 are sent to the intake manifold 6 from the return pipe 50 via the flow rate adjustment valve 26.

[0043] In this flow of blow-by gas, the opening of the port 51 faces in a direction different from the direction of the inlet 211 of the breather device 20, so that the blow-by gas remains in the breather chamber 30 for a longer time. That is, the blow-by gas is introduced from the port 51 to the right into the breather chamber 30, hits the inner wall, and spreads within the breather chamber 30. Then, it spreads upward while hitting the rear inner wall of the breather chamber 30, and enters the internal space 210 of the main body case 21 through the inlet 211 provided above the breather device 20. The blow-by gas that has entered the internal space 210 travels from rear to front within the internal space 210 and hits the inner wall. In the internal space 210, oil components with a high specific gravity tend to fall downward along the inclined surface 22, while gas components with a low specific gravity tend to advance upward to the delivery passage 23. This effectively separates the oil components from the gas components.

[0044] The oil components that fall downward along the inclined surface 22 are discharged from a discharge port 212 provided at the bottom of the main body case 21 and returned to the crankcase 5 via a port 51 in the breather chamber 30. To make it easier to collect the oil components as they fall along the inclined surface 22, the inclined surface 22 may be provided with grooves or protrusions extending in the vertical direction.

[0045] The breather device 20 used in the blow-by gas treatment device 10 according to this embodiment introduces blow-by gas into the internal space 210 from an upper inlet 211, even with a small main body case 21, and uses the inclined surface 22 to discharge the separated oil component from a lower outlet 212. The breather device 20 is incorporated into the breather chamber 30 provided in the space diagonally above the crankcase 5. The breather device 20 introduces blow-by gas from below the breather chamber 30, diffuses it above the breather chamber 30, and then introduces it back into the internal space 210 of the main body case 21 from an inlet 211 provided above the breather device 20. This allows the blow-by gas to circulate a longer distance, allowing the oil component and gas component to be separated from the blow-by gas. Furthermore, because the oil component can be effectively separated from the blow-by gas, the intrusion of the oil component into the flow control valve 26 is suppressed.

[0046] According to this embodiment, it is possible to provide the blow-by gas processing device 10 and the engine 1 that can effectively separate the oil components and gas components contained in the blow-by gas.

[0047] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. For example, the configurations of the above embodiments can be partially omitted or arbitrarily combined in a different manner from the above. [Explanation of symbols]

[0048] 1...engine, 2...cylinder head, 3...head cover, 4...cylinder block, 5...crankcase, 6...intake manifold, 7...exhaust manifold, 8...fuel injection device, 10...blow-by gas treatment device, 20...breather device, 21...main body case, 21a...inclined plate, 21b...flange portion, 21c...mounting hole, 21d...mounting bolt, 21h...opening, 22...inclined surface, 23...delivery flow passage portion, 24...lid body, 25...extension portion, 26...flow rate adjustment valve, 30...breather chamber, 40...cylinder, 41...piston, 42...piston valve, 50...return pipe, 51...port, 60...fresh air delivery pipe, 60a one end, 60b...other end, 61...upper pipe portion, 62...lower pipe portion, 65...intake portion, 67...inlet port, 81...injector, 210...internal space, 211...inlet port, 212...exhaust port

Claims

1. A blow-by gas treatment device that treats blow-by gas sent to a crankcase disposed below a cylinder block and returns the gas to an intake manifold disposed above the cylinder block, a breather chamber communicating with a port located proximal to one side in the front-rear direction and one side in the left-right direction of the crankcase, and accommodating the blow-by gas discharged from the port; a breather device attached to the breather chamber, the breather device having an inlet port for taking the blow-by gas contained in the breather chamber into an internal space, an outlet port for discharging oil components separated from the blow-by gas, and a delivery flow path portion for delivering upward the gas components separated from the blow-by gas; a return pipe provided between the delivery passage portion and an introduction port located proximal to the other side of the intake manifold in the front-rear direction, for returning the gas component delivered from above the breather device from the introduction port to the intake manifold; A blow-by gas treatment device comprising:

2. 2. The blow-by gas treatment device according to claim 1, wherein the inlet of the breather device is provided in the breather chamber distal to the port of the crankcase.

3. The blow-by gas treatment device according to claim 1 , wherein the inlet of the breather device faces the other side in the front-rear direction.

4. 2. The blow-by gas treatment device according to claim 1, wherein an opening area of ​​the inlet of the breather device is larger than an opening area of ​​the outlet of the breather device.

5. 2. The blow-by gas treatment device according to claim 1, wherein an inclined surface is provided inside the breather device, the inclined surface being inclined downward from the inlet side toward the outlet side.

6. 6. The blow-by gas treatment device according to claim 5, wherein the outlet of the breather device is provided below the inclined surface.

7. the inlet of the breather device is located near an upper portion of the breather chamber, and the inlet faces the other side in the front-rear direction; 2. The blow-by gas treatment device according to claim 1, wherein the port of the crankcase is located proximate to a lower portion of the breather chamber, and the port faces one side in the left-right direction.

8. a flow rate adjusting valve fixed to the delivery channel portion; 2. The blow-by gas treatment device according to claim 1, wherein the return pipe is connected to the delivery passage portion via the flow rate adjustment valve.

9. The blow-by gas treatment device according to claim 8, wherein the flow rate adjusting valve extends in the front-rear direction.

10. An engine equipped with a return path that processes and returns blow-by gas from a crankcase to an intake manifold, An engine, wherein the blow-by gas treatment device according to any one of claims 1 to 8 is provided in the return path.

11. the intake manifold has an upper pipe portion and a lower pipe portion extending obliquely downward from the upper pipe portion toward a piston valve, an injector that injects fuel is connected to the outside of the lower pipe portion along an extension line of the lower pipe portion; The engine of claim 10, wherein the breather device is located below the injector.

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