JP7439005B2 - engine - Google Patents

Description

The present invention relates to an engine.

BACKGROUND ART Conventionally, an engine is known in which blow-by gas, which is gas leaking from a combustion chamber, is returned to an intake pipe and sent to the combustion chamber again (for example, see Patent Document 1). Patent Document 1 describes an engine in which an upstream end of a blowby gas return pipe is connected to a blowby gas outlet of a blowby gas return device, and a downstream end of the blowby gas return pipe is connected to an intake pipe.

Japanese Patent Application Publication No. 2017-198123

Incidentally, depending on the region where the engine is used, blow-by gas does not need to be returned to the intake system and can be discharged into the atmosphere. In this case, the upstream end of the blowby gas exhaust pipe that discharges blowby gas is connected to the blowby gas exhaust port, while the downstream end of the blowby gas exhaust pipe is not connected to the intake system. In other words, only the upstream end of the blow-by gas exhaust pipe is fixed. Therefore, since the blow-by gas exhaust pipe swings due to engine vibration, there is a risk that the blow-by gas exhaust pipe may come into contact with other parts of the engine.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an engine that can prevent an exhaust pipe that discharges blow-by gas from coming into contact with other parts.

An engine according to one aspect of the present invention includes an engine body, a head cover, an exhaust pipe, and a fixing member. The engine body includes a combustion chamber. The head cover is arranged above the engine main body. The discharge pipe is connected to the head cover. The exhaust pipe discharges blow-by gas, which is gas leaked from the combustion chamber, into the atmosphere. The fixing member fixes the exhaust pipe to the engine body.

According to the present invention, it is possible to provide an engine that can prevent an exhaust pipe that discharges blow-by gas from coming into contact with other parts.

FIG. 1 is a perspective view showing the structure of an engine according to an embodiment of the present invention. FIG. 2 is a perspective view showing a structure around a fixing member of an engine according to an embodiment of the present invention. 1 is an exploded perspective view showing a structure around an exhaust pipe of an engine according to an embodiment of the present invention. FIG. 1 is a perspective view showing a structure around an exhaust pipe and an exhaust manifold of an engine according to an embodiment of the present invention. FIG. 2 is an enlarged side view showing the structure around the downstream end of the discharge pipe according to an embodiment of the present invention.

Hereinafter, embodiments of an engine according to the present invention will be described with reference to the drawings. In addition, in the drawings, the same reference numerals are given to the same or corresponding parts, and the description will not be repeated. In this specification, in order to facilitate understanding, a first direction X, a second direction Y, and a third direction Z that intersect with each other are appropriately described. The first direction X and the second direction Y are substantially parallel to the horizontal direction, and the third direction Z is substantially parallel to the vertical direction. In this specification, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they do not need to be orthogonal to each other. Hereinafter, one side X1 in the first direction X indicates the left side of the engine, and the other side X2 in the first direction X indicates the right side of the engine. Further, one side Y1 in the second direction Y indicates the front side (front side) of the engine, and the other side Y2 in the second direction Y indicates the back side (rear side) of the engine. Further, one side Z1 in the third direction Z indicates the upper side, and the other side Z2 in the third direction Z indicates the lower side. However, the left-right direction, front-rear direction, and up-down direction are only defined for convenience of explanation, and the orientation of the engine according to the present invention during use and assembly is not limited.

An engine 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a perspective view showing the structure of an engine 1 according to an embodiment of the present invention. The engine 1 is installed, for example, in a working machine such as an agricultural machine, a construction machine, or a civil engineering machine.

As shown in FIG. 1, the engine 1 includes an engine body 2, a head cover 5, an oil pan 6, a cooling fan 7, and a crankshaft 10. Engine body 2 includes a combustion chamber (not shown). Further, the engine body 2 further includes at least a cylinder block 3.

A crankshaft 10 is arranged inside the cylinder block 3. Crankshaft 10 is an output shaft. The crankshaft 10 is arranged along the front-rear direction. Both ends of the crankshaft 10 protrude from the cylinder block 3 to the outside.

The cylinder block 3 includes a right side (not shown), a left side 3a, and a mounting portion 3b. The mounting portions 3b are arranged at the front and rear portions of the right side and left side 3a of the cylinder block 3, respectively. The mounting portion 3b is fixed to the chassis (not shown) of the working machine using a bolt via a vibration isolating member such as rubber. The left side surface 3a of the cylinder block 3 is an example of "one side surface of the cylinder block" of the present invention.

The engine 1 further includes an intake manifold (not shown) and an exhaust manifold 11. Further, the engine body 2 further includes a cylinder head 4. Cylinder head 4 is arranged above cylinder block 3. The intake manifold is arranged on the right side (not shown) of the cylinder head 4. The intake manifold supplies air to each cylinder (not shown) of the engine body 2. The exhaust manifold 11 is arranged on the left side surface 4a of the cylinder head 4. Exhaust manifold 11 is connected to cylinder head 4 . Exhaust gas is discharged from the cylinder head 4 to the exhaust manifold 11 .

The head cover 5 is arranged above the engine body 2. That is, the head cover 5 is arranged above the cylinder head 4.

The oil pan 6 is arranged below the engine body 2. That is, the oil pan 6 is arranged below the cylinder block 3. The oil pan 6 stores lubricating oil. The lubricating oil in the oil pan 6 is supplied to each part of the engine 1 and then returns to the oil pan 6.

The cooling fan 7 is arranged in front of the engine body 2. The engine 1 further includes a belt 12 disposed in front of the engine body 2. Rotational driving force is transmitted to the cooling fan 7 from the front end of the crankshaft 10 via a belt 12 .

The engine 1 further includes a flywheel (not shown) and a flywheel housing 13. The flywheel housing 13 is arranged at the rear of the engine body 2. The flywheel housing 13 houses the flywheel. The flywheel is attached to the rear end of the crankshaft 10. The rotational driving force of the crankshaft 10 is transmitted to the working part of the working machine via the flywheel.

Continuing to refer to FIG. 1, the structure around the engine body 2 will be described. The engine 1 further includes a supercharger 20, an intake pipe 23, a supercharging pipe (not shown), and an exhaust communication pipe 25. The supercharger 20 increases the pressure of air supplied to the engine body 2. The supercharger 20 is arranged on the left side of the head cover 5. Supercharger 20 includes a compressor case 21 and a turbine case 22. The compressor case 21 includes a blower foil (not shown). The turbine case 22 houses a turbine foil (not shown).

The intake pipe 23 is connected to the intake inlet of the compressor case 21. The supercharging pipe is connected to the intake outlet of the compressor case 21. Further, the supercharging pipe is connected to an intake manifold (not shown) via an EGR device (exhaust gas recirculation device) not shown.

The exhaust manifold 11 extends rearward from a front portion on the left side surface 4a of the cylinder head 4. Exhaust manifold 11 is connected to an exhaust inlet of turbine case 22 . An exhaust communication pipe 25 is connected to an exhaust outlet of the turbine case 22 . The exhaust communication pipe 25 is connected to a tail pipe (not shown) via an exhaust gas purification device (not shown). Therefore, the exhaust gas discharged from each cylinder (not shown) of the engine body 2 to the exhaust manifold 11 passes through the turbine case 22 of the supercharger 20, the exhaust connecting pipe 25, the exhaust gas purification device, the tail pipe, etc. It is discharged to the outside. The exhaust gas purification device collects particulate matter and the like in the exhaust gas.

The engine 1 further includes an EGR (Exhaust Gas Recirculation) cooler 30, a cooling water outlet pipe 31, and an EGR pipe 33. The exhaust manifold 11 extends to the rear end of the left side surface 4a of the cylinder head 4. A rear end portion 11a of the exhaust manifold 11 is connected to an EGR cooler 30. A portion of the exhaust gas within the exhaust manifold 11 is sent to the EGR cooler 30. The cooling water outlet pipe 31 is connected to the left side surface 3a of the cylinder block 3. Cooling water that has cooled the cylinder block 3 is discharged to the cooling water outlet pipe 31 . Further, the cooling water outlet pipe 31 is connected to the EGR cooler 30. Exhaust gas within the EGR cooler 30 is cooled by cooling water passing through the cooling water outlet pipe 31. The EGR cooler 30 is connected to an EGR device (not shown) via an EGR pipe 33. The EGR device returns part of the exhaust gas to the intake system as EGR gas. Note that the exhaust manifold 11 and the EGR pipe 33 may be integrally molded.

In the engine 1, part of the exhaust gas in the exhaust manifold 11 and air in the intake pipe 23 are mixed together and sent to the engine body 2 through an EGR device (not shown) and an intake manifold (not shown). is supplied to each cylinder. A portion of the exhaust gas is recirculated to each cylinder via the EGR device or the like, thereby reducing the combustion temperature in the engine 1. Therefore, the amount of nitrogen oxides (NOx) emitted from the engine 1 is reduced, and the fuel efficiency of the engine 1 is improved.

Next, with reference to FIGS. 1 and 2, the exhaust pipe 40 of the engine 1 of this embodiment will be described. FIG. 2 is a perspective view showing the structure around the fixing member 50 of the engine 1 of this embodiment.

As shown in FIG. 1, the engine 1 further includes an exhaust pipe 40. The discharge pipe 40 is connected to the head cover 5. The exhaust pipe 40 is a pipe for exhausting blow-by gas generated in the engine body 2 into the atmosphere. Blowby gas is gas that leaks from the combustion chamber. Specifically, the head cover 5 includes a left side surface 5a and an outlet 5b disposed on the left side surface 5a. The discharge port 5b discharges blow-by gas to the outside of the head cover 5. An upstream end 40a of the discharge pipe 40 is connected to the discharge port 5b. That is, the blow-by gas is discharged into the atmosphere from the discharge port 5b via the discharge pipe 40. The exhaust pipe 40 extends downward from the exhaust port 5b along the left side of the engine body 2.

Engine 1 further includes a fixing member 50. The fixing member 50 fixes the exhaust pipe 40 to the engine body 2. Therefore, a gap can be secured between the exhaust pipe 40 and other parts of the engine 1, and swinging of the exhaust pipe 40 due to vibrations of the engine 1 can be suppressed. As a result, the exhaust pipe 40 can be prevented from coming into contact with other parts of the engine 1.

Specifically, the exhaust pipe 40 is fixed to the engine body 2 at least at one location other than the upstream end 40a. The fixing member 50 includes, but is not particularly limited to, a holding plate 51 and a bolt 52, as shown in FIG. 2, for example. The holding sheet metal 51 includes a holding part 51a that holds the discharge pipe 40 (see FIG. 1). The holding portion 51a is curved along the outer peripheral surface of the discharge pipe 40. The discharge pipe 40 is fixed to the holding portion 51a by, for example, welding. The holding metal plate 51 is fastened to the engine body 2 with bolts 52.

In this embodiment, as shown in FIG. 1, the engine 1 includes a plurality of fixing members 50. The exhaust pipe 40 is fixed at multiple locations on the cylinder block 3 by multiple fixing members 50 . Therefore, compared to the case where the exhaust pipe 40 is fixed to separate parts such as the cylinder head 4 and the cylinder block 3, the exhaust pipe 40 may be deformed or assembled due to assembly errors. You can prevent it from disappearing.

In this embodiment, for example, the engine 1 includes two fixing members 50. The discharge pipe 40 is fixed at two locations on the cylinder block 3 by two fixing members 50. Specifically, the discharge pipe 40 is fixed to a portion of the cylinder block 3 on the oil pan 6 side by a fixing member 50. The part of the cylinder block 3 on the oil pan 6 side is the part of the cylinder block 3 below the center in the vertical direction. Therefore, the downstream end 40b of the discharge pipe 40 or a portion near the downstream end 40b can be fixed. That is, the portion of the discharge pipe 40 that is far from the upstream end 40a connected to the discharge port 5b is fixed. As a result, shaking of the exhaust pipe 40 due to vibrations of the engine 1 can be effectively suppressed. In this embodiment, the downstream end 40b of the discharge pipe 40 is fixed to the lower end 3c of the left side surface 3a of the cylinder block 3 by a fixing member 50.

Further, the exhaust pipe 40 is fixed to a portion of the left side surface 3a of the cylinder block 3 on the exhaust manifold 11 side by a fixing member 50. The portion of the cylinder block 3 on the exhaust manifold 11 side is the portion of the cylinder block 3 above the center in the vertical direction. The left side surface 3a of the cylinder block 3 is arranged below the exhaust manifold 11. Since the left side surface 3a of the cylinder block 3 is on the exhaust side, the left side surface 3a of the cylinder block 3 tends to reach a high temperature. The exhaust pipe 40 is arranged in a portion of the left side surface 3a on the exhaust manifold 11 side, which is particularly hot. Therefore, even in a low-temperature environment, it is possible to suppress the moisture inside the discharge pipe 40 from freezing. In this embodiment, the discharge pipe 40 is fixed to the upper end 3d of the left side surface 3a of the cylinder block 3 by a fixing member 50. Further, the exhaust pipe 40 is fixed below the exhaust manifold 11 at the upper end 3d of the left side surface 3a.

Next, the structure of the discharge pipe 40 will be further described with reference to FIGS. 1 and 3 to 5. FIG. 3 is an exploded perspective view showing the structure around the exhaust pipe 40 of the engine 1 of this embodiment. FIG. 4 is a perspective view showing the structure around the exhaust pipe 40 and exhaust manifold 11 of the engine 1 of this embodiment. FIG. 5 is an enlarged side view showing the structure around the downstream end 40b of the discharge pipe 40 of this embodiment.

The exhaust pipe 40 is arranged to pass through the side of the exhaust manifold 11 from above to below. Therefore, compared to the case where the exhaust pipe 40 is curved so as to pass in front or behind the exhaust manifold 11, the length of the exhaust pipe 40 can be suppressed from increasing. Furthermore, since heat is transferred from the exhaust manifold 11, which becomes particularly hot, to the exhaust pipe 40, freezing of moisture inside the exhaust pipe 40 can be further suppressed.

Specifically, as shown in FIG. 3, the discharge pipe 40 includes, in addition to an upstream end 40a and a downstream end 40b, an attachment part 40c, a detour part 40d, a vertical part 40e, an inclined part 40f, and a vertical part 40c. It further includes a section 40g.

The attachment portion 40c includes an upstream end portion 40a. As shown in FIG. 4, the mounting portion 40c is arranged above the exhaust manifold 11. The attachment portion 40c is attached to the head cover 5. The attachment portion 40c is connected to the discharge port 5b of the head cover 5. Moreover, the attachment part 40c is connected to the detour part 40d. The detour portion 40d is arranged so as to avoid the exhaust manifold 11. That is, the detour portion 40d moves away from the left side surface 5a of the head cover 5, passes along the side of the exhaust manifold 11 substantially vertically downward, and then curves toward the left side surface 3a of the cylinder block 3. In other words, the detour portion 40d is arranged so as to straddle the exhaust manifold 11 above and below. Further, the detour portion 40d is arranged to pass between the exhaust manifold 11 and the intake pipe 23. The detour portion 40d is connected to the vertical portion 40e. The vertical portion 40e is arranged below the exhaust manifold 11. The vertical portion 40e extends vertically downward along the left side surface 3a of the cylinder block 3. The vertical portion 40e is connected to the inclined portion 40f (see FIG. 3).

As shown in FIG. 1, the inclined portion 40f (see FIG. 3) is arranged below the exhaust manifold 11. The inclined portion 40f is arranged along the left side surface 3a of the cylinder block 3. The inclined portion 40f slopes downward from the vertical portion 40e (see FIG. 3) toward the rear side. That is, the inclined portion 40f extends downward while avoiding the attachment portion 3b. The inclined portion 40f is connected to the vertical portion 40g (see FIG. 3). The vertical portion 40g includes a downstream end portion 40b (see FIG. 3). The vertical portion 40g extends vertically downward along the left side surface 3a of the cylinder block 3. As shown in FIG. 5, the vertical portion 40g extends below the cylinder block 3.

Continuing, the structure of the discharge pipe 40 will be further described with reference to FIGS. 3 and 5. As shown in FIG. 3, the discharge pipe 40 includes an elastic pipe 41 connected to the head cover 5 and having elasticity, and a metal pipe 42 connected to the elastic pipe 41. By including the metal pipe 42 in the exhaust pipe 40, the metal pipe 42 can be brought closer to the engine body 2. As a result, the degree of freedom in piping layout of the discharge pipe 40 can be improved. Furthermore, by connecting the head cover 5 and the metal tube 42 with the elastic tube 41, transmission of vibrations from the head cover 5 to the metal tube 42 can be suppressed.

Specifically, the elastic tube 41 has heat resistance. Although the material of the elastic tube 41 is not particularly limited, the elastic tube 41 is made of, for example, acrylic rubber. The elastic tube 41 corresponds to the attachment portion 40c. The elastic tube 41 is connected to the outlet 5b of the head cover 5. The elastic tube 41 is fixed to the outlet 5b using a fastener 45. Elastic tube 41 is connected to metal tube 42 . Elastic tube 41 is fixed to metal tube 42 using fasteners 46 .

The metal tube 42 corresponds to a detour portion 40d, a vertical portion 40e, an inclined portion 40f, and a vertical portion 40g. The metal tube 42 is made of metal. The metal tube 42 is composed of a single member. That is, the detour portion 40d, the vertical portion 40e, the inclined portion 40f, and the vertical portion 40g are configured by a single member.

At least a portion (detour portion 40d) of the exhaust pipe 40 disposed on the side of the exhaust manifold 11 is made of metal. Therefore, deterioration of the exhaust pipe 40 due to heat from the exhaust manifold 11 can be suppressed.

The metal tube 42 has a bulge portion (also referred to as a bulge portion) 42b having a larger diameter than other portions of the metal tube 42 at an upstream end portion 42a. The elastic tube 41 is connected to cover the bulge 42b of the metal tube 42. Further, the metal tube 42 has a bulge portion 42d having a larger diameter than other portions of the metal tube 42 at the downstream end portion 42c. Therefore, a rubber hose, for example, can be connected to the downstream end 42c of the metal tube 42. Therefore, the blow-by gas discharge position can be changed as appropriate depending on the structure of the working machine in which the engine 1 is mounted. Note that the downstream end portion 42c is an example of the “lower end portion” of the present invention.

The downstream end 42c of the metal tube 42 corresponds to the downstream end 40b of the discharge pipe 40. As shown in FIG. 5, the bulging portion 42d is arranged below the cylinder block 3.

Further, in this embodiment, the engine 1 further includes a pipe 43. The tube 43 has elasticity, for example. The pipe 43 is made of, for example, a rubber hose. The tube 43 does not need to have heat resistance. The pipe 43 is connected to the downstream end 42c of the metal pipe 42. The tube 43 is connected to cover the bulge 42d of the metal tube 42. Tube 43 is secured to metal tube 42 using fasteners 47 .

The lower end 43a of the tube 43 has an inclined surface 43b. The inclined surface 43b is inclined with respect to the direction in which the tube 43 extends. Therefore, the cross-sectional area of the outlet (not shown) of the tube 43 becomes larger than when the lower surface of the tube 43 is formed perpendicular to the direction in which the tube 43 extends. Since the moisture inside the tube 43 freezes from the edge of the outlet, it is possible to prevent ice generated by freezing from blocking the outlet of the tube 43. Moreover, the water inside the pipe 43 flows downward along the inclined surface 43b. Therefore, water is less likely to accumulate in the upper portion of the outlet of the pipe 43. Therefore, it is possible to further prevent ice generated by freezing from clogging the outlet of the pipe 43.

Further, the tube 43 is attachable to and detachable from the metal tube 42 . For example, when changing the blow-by gas discharge position in accordance with the structure of the working machine, the pipe 43 is changed to another rubber hose as appropriate.

The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof. Moreover, various inventions can be formed by appropriately combining the plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be combined as appropriate. The drawings mainly show each component schematically for ease of understanding, and the thickness, length, number, spacing, etc. of each component shown in the diagram may differ from the actual one for convenience of drawing. It may be different. Furthermore, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples, and are not particularly limited, and various changes can be made without substantially departing from the effects of the present invention. be.

For example, in the above embodiment, an example is shown in which the exhaust pipe 40 is fixed to two locations on the cylinder block 3 using the fixing member 50, but the present invention is not limited to this. For example, the discharge pipe 40 may be fixed to one or more locations of the cylinder block 3 using the fixing member 50.

Further, in the above embodiment, an example is shown in which the exhaust pipe 40 is arranged on the exhaust side (left side) of the cylinder block 3, but the present invention is not limited to this. For example, the exhaust pipe 40 may be arranged on the intake side (right side) of the cylinder block 3.

Further, in the above embodiment, an example is shown in which the discharge pipe 40 is fixed to the cylinder block 3, but the present invention is not limited to this. For example, the exhaust pipe 40 may be fixed to the cylinder head 4.

The present invention is useful in the field of engines.

1: Engine 2: Engine body 3: Cylinder block 3a: Left side (one side)
4: Cylinder head 5: Head cover 6: Oil pan 11: Exhaust manifold 40: Exhaust pipe 40d: Detour part (portion placed on the side of the exhaust manifold)
41: Elastic tube 42: Metal tube 42c: Downstream end (lower end)
42d: Swelling part 50: Fixed member

Claims (8)

The engine body including the combustion chamber,
a head cover disposed above the engine body;
an exhaust pipe connected to the head cover and discharging blow-by gas, which is gas leaking from the combustion chamber, into the atmosphere;
a fixing member that fixes the exhaust pipe to the engine body ;
exhaust manifold and
an intake pipe that takes in air to be supplied to the engine body;
Equipped with
The engine body further includes a cylinder block and a cylinder head disposed above the cylinder block,
the exhaust manifold is connected to the cylinder head,
The exhaust pipe is arranged to pass between the exhaust manifold and the intake pipe . comprising a plurality of the fixing members ,
The engine according to claim 1, wherein the exhaust pipe is fixed to a plurality of locations on the cylinder block by the plurality of fixing members. further comprising an oil pan disposed below the cylinder block,
The engine according to claim 1 or 2, wherein the exhaust pipe is fixed to a portion of the cylinder block on the oil pan side by the fixing member. The cylinder block has one side disposed below the exhaust manifold,
The engine according to any one of claims 1 to 3, wherein the exhaust pipe is fixed to a portion of one side of the cylinder block on the exhaust manifold side by the fixing member. The engine according to any one of claims 1 to 4 , wherein the exhaust pipe is arranged to pass from above to below the exhaust manifold. The engine according to any one of claims 1 to 5, wherein at least a portion of the exhaust pipe disposed on a side of the exhaust manifold is made of metal. The engine according to any one of claims 1 to 6 , wherein the exhaust pipe includes an elastic tube connected to the head cover and having elasticity, and a metal tube connected to the elastic tube. The engine according to claim 7, wherein the metal tube has a bulge at a lower end having a diameter larger than that of other parts of the metal tube.

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