JP2022104363A - Industrial engine - Google Patents

Abstract

To provide an industrial engine improved so as to enhance ventilation efficiency in the engine by further devising an intake structure of fresh air into the engine.SOLUTION: In an industrial engine, blow-by gas from a crank case 1A is guided to an intake passage e through the inside of a head cover 3, and an air passage 20 for supplying air in the intake passage e to an engine case k located on a crank axial center P side of a cylinder head 2 is provided. The air passage 20 comprises external piping connecting the engine case k and the intake passage e in the vicinity of a portion 16A where the air passage 20 of the intake passage k is communicated.SELECTED DRAWING: Figure 3

Description

The present invention relates to an industrial engine having a blow-by gas recirculation device capable of introducing fresh air into the engine.

The blow-by gas recirculation device is configured to guide the blow-by gas generated in the crankcase to the intake passage through the inside of the cylinder head and the inside of the head cover. Specifically, in order to prevent the pressure rise in the engine (inside the crankcase) due to blow-by gas and to prevent the engine oil from becoming dirty, blow-by gas is discharged to the intake passage through a pressure regulating valve such as a PCV valve provided on the head cover. Many are configured to do so.

In order to effectively prevent the above-mentioned increase in engine pressure and oil contamination due to blow-by gas, a fresh air introduction passage and a blow-by gas discharge passage are connected to the inside of the engine, and the blow-by gas is used as an intake passage through these passages. Some have adopted a return configuration. As a technique for ventilating a crankcase by introducing fresh air, for example, those disclosed in Patent Document 1 and Patent Document 2 are known.

In an engine that can take in fresh air into the crankcase, normally, blow-by gas is returned to the intake passage by the negative pressure of the intake passage through the pressure regulating valve, and the internal pressure of the engine (inside the crankcase) is adjusted to make the fresh air. Fresh air is introduced from the introduction passage. When the load is high, the amount of blow-by gas may exceed the flow rate of the pressure regulating valve, and the blow-by gas may be returned to the intake passage through the fresh air introduction passage.

Japanese Unexamined Patent Publication No. 2018-168814 Japanese Unexamined Patent Publication No. 2012-57575

In the above-mentioned prior art (Patent Documents 1 and 2), a structure is adopted in which fresh air from the intake passage is supplied to the head cover, and the blow-by gas is taken out from the gas outlet provided with the pressure regulating valve in the head cover. Depending on the case, the fresh air supplied to the head cover may pass through only the inside of the head cover and exit from the gas outlet without circulating in the crankcase, which may reduce the ventilation efficiency in the engine (inside the crankcase). ..

An object of the present invention is to provide an industrial engine improved so as to improve the ventilation efficiency in the engine by further devising a structure for taking in fresh air into the engine.

The present invention relates to an industrial engine.
The blow-by gas from the crankcase is configured to be guided to the intake passage through the inside of the head cover, and an air passage for supplying the air in the intake passage to the engine case located on the crank axis side from the cylinder head is provided. ,
The air passage is characterized by being formed of an external pipe connecting the engine case and the intake passage in the vicinity of a portion of the intake passage through which the air passage is communicated.

It is convenient that the fuel supply device that mixes fuel and air is arranged in the vicinity of the intake manifold, and the air passage is connected to the air supply portion in the fuel supply device. Further, it is more convenient that the front fuel supply device is arranged on the lateral side of the intake manifold in the direction of the crank axis.

Regarding the present invention, refer to claims 4 to 7 for feature configurations and means other than the above-mentioned configurations (means).

According to the present invention, since the fresh air is introduced into the engine case located on the crank axis side of the cylinder head, the fresh air passes through the inside of the head cover and the head cover is compared with the case where the fresh air is introduced into the internal space of the head cover. It is suppressed that it goes out to the gas outlet of the engine, and fresh air is guided to the inside of the engine case located on the crank axis side from the cylinder head, so that the original ventilation action is strengthened.

For example, when the pressure regulating valve is blocked due to freezing at high load or extremely low temperature, the air passage, which is the fresh air introduction passage, may become a passage to the blow-by gas intake passage, but the air passage is a pipe pipe. Since it is exposed to the outside air such as the road, it is possible that the air passage freezes and becomes blocked at extremely low temperatures such as in the midwinter.

In order to promote ventilation, it is better to supply fresh air to the lower part of the engine case such as the crankcase as much as possible, but in that case, the fresh air introduction passage becomes long and it is easy to cause the above-mentioned blockage. There is a disadvantage. In the present invention, since the air passage is communicated with the engine case near the place where the air passage of the intake passage is communicated, the length of the air passage can be shortened as much as possible. Therefore, the ventilation action is strengthened as compared with the case of supplying fresh air to the head cover, and the freezing of the air passage is suppressed as compared with the case of supplying fresh air to the crankcase, so that the possibility of blockage due to freezing is reduced. However, it is possible to realize a ventilation device in which the ventilation action is promoted.

As a result, it is possible to provide an industrial engine in which the ventilation efficiency in the engine is improved by further devising the structure for taking in fresh air into the engine at the engine layout stage.

Right side view of industrial engine Rear view of industrial engine Perspective view of the ventilation system seen from diagonally forward and above Perspective view of the ventilation system seen from the side diagonally behind Rear view of the main part showing the main body of the auxiliary machine case to which the lid case is assembled ZZ line sectional view of FIG. 5 showing the structure of the rotation angle detection device (auxiliary device). The lid case is shown, (A) is a front view, and (B) is a left side view. The main parts of another engine are shown, (A) is a right side view, and (B) is a rear view. Partial notch side view of the main part showing an example of an auxiliary device for compression ignition

Hereinafter, embodiments of the industrial engine according to the present invention will be described with reference to the drawings in the case of a spark ignition engine (gas / gasoline engine, etc.) used for agricultural machinery, construction machinery, generators, working machinery, and the like.

As shown in FIGS. 1 and 2, the industrial engine E (hereinafter, simply referred to as “engine”) includes a cylinder block 1, a cylinder head 2 assembled on the cylinder block, and a cylinder head 2. It has a head cover 3 that can be assembled to the cylinder. The cylinder block 1 has a crankcase 1A to which an oil pan 4 is mounted below, and a cylinder 1B in which a piston (not shown) is housed.

The front portion of the engine E is equipped with a drive pulley 5 having a crank axis P, an engine cooling fan 6, a water flange 7, and the like, and the rear portion of the engine E is equipped with a flywheel housing 8. An exhaust manifold 9 and an exhaust cover 10 covering the exhaust manifold 9 are mounted on the upper left side of the engine E, and an intake manifold 11 is mounted on the upper right side of the engine E. The intake manifold 11 includes a plurality of branch pipes 11a and an intake main body 11A that communicates with the plurality of branch pipes 11a.

In FIGS. 1 and 2, an alternator 12, an ECU 13, an oil filter 14, a starter 15, a rotation angle detecting device D, and the like are provided on the right side of the cylinder block 1. Behind the intake manifold 11, a mixer (gas mixer) 16 that mixes fuel (gas) and air is arranged so as to communicate with the intake main body 11A. The mixer 16 which is a fuel supply device is arranged on the right side at the upper part of the rear end portion as the engine E, and the flywheel housing 8 is located diagonally to the lower left. The air (fresh air: fresh air) from the air cleaner (not shown) enters the intake flange 16A (an example of the intake passage e) of the mixer 16.

As shown in FIGS. 1 and 2, the blow-by gas generated in the crankcase 1A is transferred to the inside of the cylinder head 2, the inside of the head cover 3, and the PCV valve (pressure regulating valve) 17 provided on the upper part of the head cover 3. A blow-by gas recirculation device C that leads to the intake manifold 11 is specifically provided in the intake passage e through the air intake passage e. A pipe-shaped blow-by gas passage 18 for communicating and connecting the PCV valve 17, which is also the gas outlet of the head cover 3, and the intake main body 11A is provided.

As shown in FIGS. 3 and 4, an air passage 20 for supplying the air of the intake passage e to the cylinder block 1 (an example of the engine case k located on the crank axis P side of the cylinder head 2) is provided. (Installed), a ventilation device K is configured to directly introduce fresh air (fresh air) in the intake passage e into the internal space of the cylinder block 1. The air passage 20 is composed of an external pipe connecting the cylinder block 1 and the intake passage e in the vicinity of the portion 16A through which the air passage 20 of the intake passage e is communicated. Specifically, a crank-shaped air passage extends over the intake flange (an example of the air supply portion) 16A of the mixer 16 and the auxiliary machine case d provided in the upper right portion at the rear end portion of the cylinder block 1. 20 are connected in communication.

As shown in FIGS. 3 and 4, the auxiliary machine case d includes a main case portion 1t formed so as to extend from the upper portion of the cylinder block 1 in the rear side (an example of one end side) in the crank axis P direction to the right side. A lid case portion 21 that serves as a removable lid for the front opening (an example of the other end opening) 19 (see FIG. 6) formed on the front side (an example of the other end side) of the main case portion 1t in the crank axis P direction. It is configured to have and. Further, the auxiliary machine case d closes the rear opening (an example of one end side opening) 23 (see FIG. 6) formed on the rear side (an example of one end side) in the direction of the crank axis P of the main case portion 1t. The closed case portion 8t is provided, and the closed case portion 8t is formed to overhang the flywheel housing 8 assembled to the rear end (one end) of the cylinder block 1 in the crank axis P direction.

That is, the auxiliary machine case d is composed of a closed case portion 8t, a main case portion 1t, and a lid case portion 21, and the lid case portion 21 is attached to and detached from the main case 1T composed of the closed case portion 8t and the main case portion 1t. Bolted as possible. The auxiliary machine case d contains a rotation angle detection device D for detecting the crank angle, and the pulse rotating body 37 driven by the crank shaft 24 and the pulse detector 40 are housed in the main case 1T. (See Fig. 6).

As shown in FIGS. 5 to 7, the lid case portion 21 has a bulging portion 22 formed to project forward and outward from the lid case portion main body 21A, and the bulging portion 22 has a bulging portion 22 with respect to the air passage 20. The connection portion 31 is formed. The lid case portion main body 21A is formed with a peripheral flange portion 21a that is internally fitted in the front opening 19, and is detachably attached to the front side of the main case portion 1t by bolting structures at a plurality of locations (three locations). There is.

A fresh air introduction chamber 30 formed on the upper part of the lid case portion 21 and having a substantially rectangular shape protruding forward in the front-rear direction, and surrounded by a peripheral flange portion 21a and an upward open U-shaped surrounding rib 27 connected to the peripheral flange portion 21a. It is formed. The bulging portion 22 is formed with an outer peripheral wall 22a integrated with the peripheral flange portion 21a and a hole 30a communicating with the fresh air introduction chamber 30 from the upper surface (notation omitted) of the outer peripheral wall 22a. A connection pipe (an example of a connection portion) 31 is internally fitted in the hole 30a in a sealed state by press fitting or the like. The air passage 20 is externally connected to the connecting pipe 31.

A boss 32 is erected (on the rear side) from the side wall 22b of the bulging portion 22 on the fresh air introduction chamber 30 side, and the cover wall 33 is screwed with a bolt 34 on the top surface (notation omitted) which is the rear surface. There is. The cover wall 33 includes a left-right central plate portion 33a and left-right plate portions 33b and 33c (see FIG. 5) extending forward from each of the left and right ends thereof, and is bent in a forward-facing open U-shape in a vertical view. It is made of a formed plate material, and is provided as a member for partitioning the lower end opening 31a of the connecting pipe 31 so as not to directly face the backward opening 30A of the fresh air introduction chamber 30. The cover wall 33 exerts an effect of covering the oil and oil mist in the auxiliary equipment case d so as not to flow back into the air passage 20 as much as possible while allowing air to be taken in from the air passage 20 to the inside of the auxiliary equipment case d. It is configured to be.

As shown in FIG. 6, the rotation angle detecting device (an example of the auxiliary device for ignition) D is housed in the auxiliary machine case d. The rotation angle detection device D for detecting the crank angle includes a composite rotating body 35 rotatably supported by the lid case portion 21, and a pulse detector 40 mounted on the main case portion 1t. Has been done. The composite rotating body 35 includes a driven gear 36 pivotally fitted to a support shaft 38 bolted to the lid case portion 21 via a support plate 38A, and a pulse rotating body 37 attached to the front side of the driven gear 36. It is composed of.

The driven gear 36 is occlusally interlocked with the crank shaft 24 via a pacing gear transmission mechanism (not shown), and gear-shaped detection teeth 37a are formed on the outer peripheral portion of the pulse rotating body 37. A pulse detector 40 is internally fitted in the left-right facing mounting hole 39 formed on the right tip side of the main case portion 1t, and the detection portion 40a of the pulse detector 40 and the detection teeth 37a of the pulse rotating body 37 are provided. Are arranged relative to each other in close proximity to each other. That is, the pulse rotating body 37 and the pulse detector 40 constitute a rotation angle detecting device D for detecting the crank angle of the crank shaft 24.

The main case 1T houses a structural portion (final gear, etc.) on the lower side in the transmission direction of the pacing gear transmission mechanism (not shown), and the lid case portion 21 provided with the composite rotating body 35 is attached to the main case portion 1t. As a result, the driven gear 36 is engaged with the pacing gear transmission mechanism, and the pulse rotating body 37 is driven and rotated by the crank shaft 24. Note that 41 shown in FIG. 5 is a triangular reinforcing seat formed inside the lid case portion 21 for attaching the support plate 38A.

As shown in FIGS. 7A and 7B, the lid case portion 21 has three bolt insertion holes 42, 42, 42, two nut portions 43, 43, and an oil passage portion 44. , Reinforcing ribs 45 are formed. The nut portion 43 is used as a structural portion (see FIGS. 3 and 4) for bolting the ECU support plate 13A that supports the ECU 13. An oil passage 44A extending to the left and right is formed in the oil passage portion 44, and an oblique hole (not shown) that joins the oil passage 44A in the middle and has an external opening 44a is also formed. Reference numeral 48 is a stopcock that seals the outer end of the oil passage 44A.

The support shaft 38 is formed in a state in which a front-back axial center hole 46 that opens only forward and a lateral hole 47 that penetrates left and right communicate with each other. The front end portion 38a of the support shaft 38 is fitted in the center hole 21D of the lid case portion 21, and the oil passage 44A and the shaft center hole 46 are communicated with each other. The outer opening 44a is communicated with an opening (not shown) of an oil supply path 49 (see FIG. 5) formed in the main case portion 1t (cylinder block 1), and is communicated with an oil passage portion 44 and an axial center hole 46. , And oil is supplied to the sliding portion of the driven gear 36 through the lateral hole 47.

In the ventilation device K, since the fresh air introduction chamber 30 through which the air passage 20 is communicated is communicated with the internal space of the cylinder block 1 via the internal space of the main case 1T, it is new from the intake flange 16A of the mixer 16. Qi (fresh air) can be introduced into the internal space of the cylinder block 1, that is, the internal space of the crankcase 1A through the auxiliary machine case d.

The mixer 16 is arranged on the rear side of the intake manifold 11, and is in a positional relationship very close to the upper right portion of the flywheel housing 8, that is, the auxiliary machine case d. Therefore, the air passage 20 that communicates and connects the auxiliary machine case d and the mixer 16 that are arranged relatively close to each other can be configured by an external pipe having a length as short as possible.

[About action and effect]
In the conventional technique, since blow-by gas is derived from the PCV valve located on the upper part of the head cover, a part of fresh air (fresh air) passes through the inside of the head cover, and the ventilation efficiency inside the crankcase tends to be poor. rice field. In addition, the air passage for ventilation tends to be long, and when blow-by gas flows back through the air passage at low speed and high output (blow-by gas flows from the head cover to the upstream of the throttle), the inside of the pipe freezes (freezes) at low temperatures. There was a risk that the air passage would be blocked.

In the present invention, fresh air is introduced into the engine case k (cylinder block 1, crank case 1A, cylinder 1B, flywheel housing 8, etc.) located on the crank axis P side of the cylinder head 2, so that the inside of the head cover 3 is introduced. Compared to the case where it is introduced into the space, it is suppressed that fresh air passes through the inside of the head cover 3 and goes out to the gas outlet of the head cover 3, and the engine case k located on the crank axis P side from the cylinder head 2 Since fresh air is guided to the inside, the original ventilation action is strengthened.

For example, when the pressure regulating valve 17 such as a PCV valve is blocked due to freezing at a high load or an extremely low temperature, the air passage 20 which is a fresh air introduction passage may become a passage to the blow-by gas intake passage e. However, since the air passage 20 is exposed to the outside air such as a pipe line, it is considered that the air passage may freeze and be blocked at an extremely low temperature such as in a severe winter.

In order to promote the ventilation action, it is advisable to supply fresh air to the lower part of the engine case k such as the crankcase 1A as much as possible. There is an easy disadvantage. In the present invention, since the air passage 20 is communicated with the engine case k near the place where the air passage 20 of the intake passage e is communicated, the length of the air passage 20 can be shortened as much as possible. Therefore, the ventilation action is strengthened as compared with the case of supplying fresh air to the head cover 3, and the freezing of the air passage 20 is suppressed as compared with the case of supplying fresh air to the crankcase 1A, so that there is a possibility of blockage due to freezing. It is possible to realize a ventilation device K in which the ventilation action is promoted while lowering the pressure.

As a result, the amount of fresh air (fresh air) supplied to the cylinder block (crankcase) increases (the amount per unit time), and the length of the air passage can be shortened, improving the oil life and improving the oil life. It is possible to provide an industrial engine capable of preventing blockage of an air passage at a low temperature.

[Another Embodiment of Ventilation Device K]
As shown in FIGS. 8A and 8B, in the case of the gasoline engine E, the air passage 20 is configured to be communicatively connected to the intake flange 51 (an example of the intake passage e) of the throttle 50. Is also good. In this case, the air passage 20 is taken out from the intake flange 51 to the left, then twisted diagonally downward to the right and forward, and then communicates with the auxiliary machine case d (cover case portion 21).

[Diesel engine specifications]
As shown in FIG. 9, the front opening (the other end opening) 19 of the main case portion 1t supports the auxiliary device 28 for fuel supply (or ignition) instead of the lid case portion 21. The bracket 29 may be detachably configured. That is, the support bracket 29 supports the supply pump (an example of a fuel injection supply pump and an "auxiliary device for fuel supply (or ignition)") 28, and the pump shaft 28P of the supply pump 28 A composite rotating body 35 is attached to the vehicle.

The support bracket 29 supports the supply pump 28 by inwardly fitting the tubular protrusion 28a of the pump body 28A, and the front opening 19 of the main case portion 1t is a composite rotation as in the case of the present embodiment. It is configured in a hole large enough to allow the body 35 to be inserted and removed. That is, when the support bracket 29 having the supply pump 28 is assembled to the main case portion 1t instead of the lid case portion 21, the driven gear 36 is engaged with the final gear 52 of the pacing gear transmission mechanism (not shown), and The detection teeth 37a of the pulse rotating body 37 and the detection unit 40a of the pulse detector 40 are set to be in close contact with each other.

Although not shown, the support bracket 29 is formed with a bulging portion, and is provided with a configuration in which the air passage 20 is communicated and connected. Therefore, even in an engine having a specification in which a support bracket 29 for the auxiliary device 28 for ignition (compression ignition) is attached instead of the lid case portion 21 for the auxiliary device D for ignition, air is applied to the auxiliary device case d. It can be configured in a state where the ventilation device K through which the passage 20 is communicated functions effectively.

1A Crankcase 1T Main case 1t Main case part 2 Cylinder head 3 Head cover 8 Flywheel housing 11 Intake manifold 16 Fuel supply device 16A Communication location 19 Opening 20 Air passage 21 Lid case part D Auxiliary device for ignition P Crankshaft Heart d Auxiliary case e Intake passage k Engine case

Claims (7)

The blow-by gas from the crankcase is configured to be guided to the intake passage through the inside of the head cover, and an air passage for supplying the air in the intake passage to the engine case located on the crank axis side from the cylinder head is provided. ,
The air passage is an industrial engine including an external pipe connecting the engine case and the intake passage in the vicinity of a portion of the intake passage to which the air passage is communicated. The industrial engine according to claim 1, wherein a fuel supply device for mixing fuel and air is arranged in the vicinity of an intake manifold, and the air passage is connected to an air supply portion in the fuel supply device. The industrial engine according to claim 2, wherein the front fuel supply device is arranged on the lateral side of the intake manifold in the direction of the crank axis. The industrial engine according to claim 2 or 3, wherein the air passage is connected to an auxiliary machine case integrally formed with the engine case located below the fuel supply device. The auxiliary machine case has a main case formed in the engine case and a lid case portion that serves as a lid for an opening formed in the main case, and the air passage is connected to the lid case portion. The industrial engine according to claim 4. The industrial engine according to claim 4 or 5, wherein the auxiliary machine case is a case for accommodating an auxiliary machine device for ignition. The industrial engine according to any one of claims 4 to 6, wherein the auxiliary machine case is formed at an end portion of the engine case on the side to which a flywheel housing is connected.

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