Engine

Abstract

To provide an engine capable of preventing freezing of moisture in blow-by gas in a blow-by gas recirculation device 12 during cold starting.SOLUTION: An engine includes an engine related component P, a heat exchanger Pa of the engine related component P, an electric water pump 7, and a bypass water passage B for circulating engine cooling water 5 mutually between a main water passage M and the heat exchanger Pa of the engine related component P by the electric water pump 7, and includes, as the engine related component P, a blow-by gas recirculation device 12 for recirculating blow-by gas in a crankcase to an intake passage. The blow-by gas recirculation device 12 is heated by the engine cooling water 5 passing through the heat exchanger 12a of the blow-by gas recirculation device 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an engine, and more particularly to an engine capable of preventing freezing of moisture in blow-by gas in a blow-by gas reflux device during cold start.

Background Art

[0002] Conventionally, there has been an engine including an engine body, an electric water pump, and a water passage for circulating engine cooling water with the electric water pump, and a water passage for cooling the engine body with the engine cooling water (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] 《Problem》 It is impossible to prevent freezing of moisture in blow-by gas in a blow-by gas reflux device during cold start. The engine of Patent Document 1 operates an electric water pump during cold weather to suppress icing of the throttle device. However, even when the electric water pump is operated, it is impossible to heat the blow-by gas reflux device with engine cooling water, and it is impossible to prevent freezing of moisture in blow-by gas in the blow-by gas reflux device during cold start.

[0005] An object of the present invention is to provide an engine capable of preventing freezing of moisture in blow-by gas in a blow-by gas reflux device during cold start.

Means for Solving the Problems

[0006] The main configuration of the present invention is as follows. As illustrated in FIG. 1, an engine main body (1), a radiator (2), a mechanical water pump (4) driven by a crankshaft (3), and a main water passage (M) for circulating engine cooling water (5) between the engine main body (1) and the radiator (2) by the mechanical water pump (4) to cool the engine main body (1). Engine-related components (P), a heat exchanger (Pa) of the engine-related components (P), an electric water pump (7), and a bypass water passage (B) for circulating engine cooling water (5) between the main water passage (M) and the heat exchanger (Pa) of the engine-related components (P) by the electric water pump (7). As illustrated in FIG. 3(A), as an engine-related component (P), a blow-by gas reflux device (12) for refluxing blow-by gas (10) in a crankcase (9) to an intake passage (11) is provided. As illustrated in FIG. 1, the engine cooling water (5) passing through the heat exchanger (12a) of the blow-by gas reflux device (12) is configured to heat the blow-by gas reflux device (12). The engine is characterized by this.

Advantages of the Invention

[0007] The present invention has the following advantages. 《Advantage》 It is possible to prevent freezing of moisture in the blow-by gas (10) in the blow-by gas reflux device (12) during cold start. As illustrated in FIG. 1, according to this engine, even during cold start when the engine speed is low and the mechanical water pump (4) rotates at a low speed, an electric water pump (7) that can be driven at high speed without being affected by the engine speed allows the necessary amount of engine cooling water (5) to pass through the heat exchanger (12a) of the blow-by gas reflux device (12), and the blow-by gas reflux device (12) can be heated. Therefore, it is possible to prevent freezing of moisture in the blow-by gas (10) in the blow-by gas reflux device (12) during cold start.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] FIGS. 1 to 9 are diagrams for explaining an engine according to an embodiment of the present invention. In this embodiment, a water-cooled vertical in-line multi-cylinder diesel engine will be described.

[0010] As shown in Fig. 9, the engine body (1) of this engine includes a cylinder block (25), a cylinder head (26) assembled on the upper part of the cylinder block (25), a cylinder head cover (27) assembled on the upper part of the cylinder head (26), an engine cooling fan (28) arranged on the front side of the cylinder block (25) with the installation direction of the crankshaft (3) being the front - rear direction and one of the front - rear directions being the front side, a flywheel housing (29) assembled on the rear side of the cylinder block (25), and an oil pan (30) assembled on the lower side of the cylinder block (25). The cylinder block (25) includes a downward - inclined crankcase (9) and an upward - inclined cylinder part (31), and the crankshaft (3) is installed in the crankcase (9). As shown in Fig. 7, when viewed in a direction parallel to the front - rear direction, with the width direction of the engine body (1) perpendicular to the front - rear direction and the vertical direction being the lateral direction, an intake manifold (32) is assembled on one lateral side of the cylinder head (26), and an exhaust manifold (33) is assembled on the other lateral side of the cylinder head (26).

[0011] The engine body (1) includes an intake passage (11) shown in Fig. 3(A), a blow - by gas reflux passage (34), a fuel supply device (35) shown in Fig. 7, an exhaust passage (36) shown in Fig. 3(B), a urea - water passage (37), and a water - cooling device (38) shown in Fig. 1. The arrows in Fig. 3(A) indicate the piping and flow directions of the intake air (11a) or blow - by gas (10). The configuration of the intake passage (11) is as follows. As shown in Fig. 3(A), the intake passage (11) includes an air cleaner (39), an air compressor (40a) of a supercharger (40), an intake throttle (41), and an intake manifold (32). The intake air (11a) purified by the air cleaner (39) is compressed by the air compressor (40a), and then supercharged into the combustion chamber (not shown) through the intake throttle (41) and the intake manifold (32).

[0012] As shown in FIG. 3(A), the blow-by gas reflux path (34) is a PCV system including a crankcase (9), a cylinder head cover (27), and a blow-by gas reflux device (12). The end of the blow-by gas reflux path (34) is connected to the intake path (11) between the air cleaner (39) and the air compressor (40a). The blow-by gas (10) generated in the crankcase (9) is refluxed to the intake path (11) through the cylinder head cover (27) and the blow-by gas reflux device (12). PCV is an abbreviation for Positive Crankcase Ventilation.

[0013] The fuel supply device (not shown) includes a common rail type fuel injection device using a common rail (not shown), and supplies the fuel accumulated in the common rail from a fuel injector (not shown) to each combustion chamber.

[0014] The arrows in FIG. 3(B) indicate the piping and flow directions of the exhaust gas (14) or the aqueous urea solution (15). The configurations of the exhaust path (36) and the aqueous urea solution path (37) are as follows. As shown in FIG. 3(B), the exhaust path (36) includes an exhaust manifold (33), a DOC (44), a DPF (45), an SCR (46), and an ASC (47). The aqueous urea solution path (37) includes an aqueous urea solution tank (17), an aqueous urea solution pump (17d), and an aqueous urea solution injector (16). The aqueous urea solution injector (16) adds the aqueous urea solution (15) to the exhaust gas (14) between the DPF (45) and the SCR (46), and reduces NO x (nitric oxide) to N2 (nitrogen gas) and H2O (water vapor). The NH3 (ammonia) that slips through the SCR (46) is purified by the ASC (47). DOC is an abbreviation for Diesel Oxidation Catalyst, DPF is an abbreviation for Diesel Particulate Filter, SCR is an abbreviation for Selective Catalytic Reduction type catalyst, and ASC is an abbreviation for Ammonia Purification Oxidation Catalyst. Note that the reference numeral (52) shown in FIGS. 3(B), 7 to 9 is a DPF housing case that houses the DOC (44) and the DPF (45), and the reference numeral (53) is an SCR housing case that houses the SCR (46) and the ASC (47).

[0015] The configuration of the water cooling device (38) is as follows. As shown in FIG. 1, this engine includes an engine body (1), a radiator (2), a mechanical water pump (4) driven by a crankshaft (3), and a main water passage (M) that circulates engine cooling water (5) between the engine body (1) and the radiator (2) by the mechanical water pump (4) to cool the engine body (1). In addition, this engine includes engine-related parts (P), a heat exchanger (Pa) for the engine-related parts (P), an electric water pump (7), and a bypass water passage (B) that circulates engine cooling water (5) between the main water passage (M) and the heat exchanger (Pa) of the engine-related parts (P) by the electric water pump (7).

[0016] The arrows in FIG. 1 indicate the water passage and the flowing direction of the engine cooling water (5). The configuration of the main water passage (M) is as follows. As shown in FIG. 1, the main water passage (M) includes a cylinder jacket (1a) that surrounds a cylinder (not shown), a head jacket (1b) provided inside the cylinder head (26), and a thermostat housing (6) that houses a thermostat valve (not shown). After the engine is started, while the water temperature of the engine cooling water (5) is low, the thermostat valve is closed, and the engine cooling water (5) pumped by the mechanical water pump (4) passes through the cylinder jacket (1a), the head jacket (1b), and the thermostat housing (6) and then returns to the mechanical water pump (4). By bypassing the radiator (2), the warm-up of the engine is promoted. When the water temperature of the engine coolant (5) rises and the thermostat valve opens, the engine coolant (5) pumped by the mechanical water pump (4) flows through the cylinder jacket (1a), the head jacket (1b), the thermostat housing (6), and the radiator (2) and then returns to the mechanical water pump (4). The engine coolant (5) is cooled by heat dissipation in the radiator (2).

[0017] In this engine, engine coolant (5) is used as the heat medium of the heat exchanger (Pa) of engine-related parts (P). As shown in Fig. 3(A), this engine includes, as engine-related parts (P), a blow-by gas reflux device (12) that refluxes the blow-by gas (10) in the crankcase (9) to the intake passage (11). As shown in Fig. 1, the blow-by gas reflux device (12) is configured to be heated by the engine coolant (5) passing through the heat exchanger (12a) of the blow-by gas reflux device (12).

[0018] As shown in Fig. 1, according to this engine, even at cold start when the engine speed is low and the mechanical water pump (4) rotates at a low speed, the electric water pump (7) that can be driven at high speed without being affected by the engine speed allows the required amount of engine coolant (5) to pass through the heat exchanger (12a) of the blow-by gas reflux device (12), so that the blow-by gas reflux device (12) can be heated. Therefore, icing of the moisture in the blow-by gas (10) in the blow-by gas reflux device (12) can be prevented at cold start.

[0019] As shown in Fig. 6(B), this engine includes, as the blow-by gas reflux device (12), an oil separator (49) that separates oil (10a) from the blow-by gas (10). The oil separator (49) is configured to be heated by the engine coolant (5) passing through the heat exchanger (49h) of the oil separator (49). According to this engine, icing of the moisture in the blow-by gas (10) in the oil separator (49) can be prevented at cold start.

[0020] As shown in FIG. 6(C), this engine includes a blow-by gas reflux device (12) having a PCV valve (50) and a blow-by gas reflux passage (51), and engine cooling water (5) passing through a heat exchanger (50f) of the PCV valve (50) and a heat exchanger (not shown) of the blow-by gas reflux passage (51) is configured to heat the PCV valve (50) and the blow-by gas reflux passage (51). According to this engine, icing of moisture in the blow-by gas (10) in the PCV valve (50) and the blow-by gas reflux passage (51) can be prevented during cold start. Only one of the PCV valve (50) or the blow-by gas reflux passage (51) may be provided with a heat exchanger.

[0021] As shown in FIG. 2, this engine includes an electronic control unit (13), and the drive of the electric water pump (7) is controlled by the electronic control unit (13) so that the target rotational speed of the electric water pump (7) is maintained at a predetermined constant value. According to this engine, since the target rotational speed of the electric water pump (7) is maintained at a predetermined constant value, even when the engine rotational speed becomes low and the mechanical water pump (4) rotates at a low speed, the rotational speed of the electric water pump (7) is maintained at a constant value without being affected by the engine rotational speed, and the required amount of engine cooling water (5) passing through the heat exchanger (12a) of the blow-by gas reflux device (12) can be obtained. Even when the water temperature of the engine cooling water (5) is low, the heat required for heating the blow-by gas reflux device (12) can be dissipated from the heat exchanger (12a), and icing of moisture in the blow-by gas (10) in the blow-by gas reflux device (12) can be prevented during cold start.

[0022] The thin-line arrows shown between the electronic control unit (13) and components such as the electric water pump (7) in FIG. 2 indicate the signal paths and signal transmission directions between the electronic control unit (13) and components such as the electric water pump (7). As shown in FIG. 2, this engine includes a water temperature sensor (5a) for detecting the temperature of engine cooling water (5) and an electronic control unit (13). The driving of the electric water pump (7) is controlled by the electronic control unit (13), and the lower the temperature of the engine cooling water (5) detected by the water temperature sensor (5a), the higher the rotational speed of the electric water pump (7) may be configured. In this case, even when the temperature of the engine cooling water (5) is low, a predetermined flow rate of the engine cooling water (5) passing through the heat exchanger (12a) of the blow-by gas reflux device (12) shown in FIG. 1 can be obtained, and the heat required for heating the blow-by gas reflux device (12) can be dissipated from the heat exchanger (12a), preventing the moisture in the blow-by gas (10) from freezing in the blow-by gas reflux device (12) during cold start. The electronic control unit (13) is an engine ECU. ECU is an abbreviation for electronic control unit.

[0023] As shown in FIG. 6(D), this engine includes, as engine-related components (P), a urea water injector (16) for injecting urea water (15) into the exhaust gas (14), and is configured such that the urea water injector (16) is cooled by the engine cooling water (5) passing through the heat exchanger (16a) of the urea water injector (16).

[0024] According to this engine, since the urea water injector (16) heated by the exhaust gas (14) can be cooled by the engine cooling water (5), overheating of the urea water injector (16) can be prevented. In addition, since the heat absorbed by the engine cooling water (5) during cooling of the urea water injector (16) is dissipated by the blow-by gas reflux device (12), the heating efficiency of the blow-by gas reflux device (12) is high.

[0025] As shown in FIG. 7, this engine includes, as engine-related components (P), a urea water tank (17), and is configured such that the urea water (15) in the urea water tank (17) is heated by the engine cooling water (5) passing through the heat exchanger (17a) of the urea water tank (17).

[0026] According to this engine, since the engine coolant water (5) warms the aqueous urea in the aqueous urea tank (17), it is possible to thaw the aqueous urea (15) frozen in the aqueous urea tank (17) during cold start. Also, since the heat absorbed by the engine coolant water (5) during the cooling of the aqueous urea injector (16) is radiated to the aqueous urea (15) in the aqueous urea tank (17), the heating efficiency of the aqueous urea (15) in the aqueous urea tank (17) is high.

[0027] As shown in FIG. 2, this engine includes an electric valve (17b) that opens and closes the flow path of the engine coolant water (5) passing through the heat exchanger (17a) of the aqueous urea tank (17), a urea water temperature sensor (17c) that detects the temperature of the aqueous urea (15) in the aqueous urea tank (17), and an electronic control unit (13). In this engine, the electric valve (17b) is controlled to open and close by the electronic control unit (13). When the temperature of the aqueous urea detected by the urea water temperature sensor (17c) is in a heating required state below a predetermined threshold value, the electric valve (17b) is in an open state. When the temperature of the aqueous urea detected by the urea water temperature sensor (17c) is in a heating not required state exceeding the predetermined threshold value, the electric valve (17b) is configured to be in a closed state. According to this engine, when the temperature of the aqueous urea is high, the electric valve (17b) is in a closed state, so that the aqueous urea (15) is not heated unnecessarily.

[0028] As shown in FIG. 8, this engine includes an air conditioner (18) as an engine related component (P), and the engine coolant water (5) passing through the heat exchanger (18a) of the air conditioner (18) is configured to warm the air in the cabin (19) where the air conditioner (18) is installed. According to this engine, since the heat of the engine coolant water (5) can be radiated by the air conditioner (18), heating in the cabin (19) can be performed. Also, since the heat absorbed by the engine coolant water (5) during the cooling of the aqueous urea injector (16) is radiated by the air conditioner (18), the heating efficiency of the air conditioner (18) is high.

[0029] As shown in FIG. 2, this engine includes a solenoid valve (18b) that opens and closes a flow path of engine cooling water (5) passing through a heat exchanger (18a) of an air conditioner (18), and an operation switch (18c) that operates the air conditioner (18). When the operation switch (18c) is turned on to the operating position, the solenoid valve (18b) is opened, and when the operation switch (18c) is turned off to the operation stop position, the solenoid valve (18b) is closed.

[0030] As shown in FIG. 2, this engine includes an electronic control unit (13), a room temperature setting device (19a) that sets a target room temperature in a cabin (19) where an air conditioner (18) is installed, a room temperature sensor (19b) that detects the room temperature in the cabin (19), a water temperature sensor (5a) that detects the temperature of the engine cooling water (5), and an electronic control unit (13). When the operation switch (18c) of the air conditioner (18) is turned on to the operating position, the opening degree of the solenoid valve (18b) is adjusted based on the set room temperature set by the room temperature setting device (19a), the detected room temperature detected by the room temperature sensor (19b), and the water temperature detected by the water temperature sensor (5a) that detects the water temperature of the engine cooling water (5) under the control of the electronic control unit (13), so that the room temperature in the cabin (19) approaches the set temperature.

[0031] As shown in FIG. 1, this engine includes an iron foreign matter capturing device (20) disposed upstream of the bypass water passage (B) with respect to the electric water pump (7), and is configured such that iron foreign matter contained in the engine cooling water (5) is captured by the iron foreign matter capturing device (20).

[0032] As shown in FIG. 1, according to this engine, before iron foreign matter such as iron rust generated in the main water passage (M) or the bypass water passage (B) enters the electric water pump (7), it is captured by the iron foreign matter capturing device (20) upstream of the bypass water passage (B), so that the accumulation and jamming of iron foreign matter in the electric water pump (7) can be prevented.

[0033] A specific example 1 of the iron foreign matter capturing device (20) shown in FIGS. 4(A) and (B) will be described. The iron foreign matter capturing device (20) of Specific Example 1 includes a bypass upstream water passage portion (21) that constitutes an upstream portion of the bypass water passage (B) and a magnet (22) provided around the bypass upstream water passage portion (21), and is configured such that iron foreign matter is retained in the bypass upstream water passage portion (21) by the magnetic force of the magnet (22).

[0034] The magnet (22) used in the iron foreign matter capturing device (20) of Specific Example 1 is a permanent magnet. Also, the peripheral wall (21a) of the bypass upstream water passage portion (21) of Specific Example 1 is made of a magnetic metal.

[0035] The iron foreign matter capturing device (20) of Specific Example 1 shown in FIGS. 4(A) and (B) includes a bypass upstream water passage portion (21), a magnet holder (22a) externally fitted to the bypass upstream water passage portion (21), and a magnet (22) housed in the magnet holder (22a). The upstream end portion (21b) of the bypass upstream water passage portion (21) is connected to the thermo outlet (6a) of the thermostat housing (6) via a thermo outlet side tube (6b), and the downstream end portion (21c) communicates with the cooling water inlet (7a) of the electric water pump (7) via a water pump inlet side tube (7b). The upstream end portion (21b) of the bypass upstream water passage portion (21) is detachably connected to the thermo outlet side tube (6b), and the downstream end portion (21c) is detachably connected to the water pump inlet side tube (7b), so that the iron foreign matter capturing device (20) can be removed from the bypass water passage (B) to clean or replace the iron foreign matter capturing device (20). The magnet (22) may be an electromagnet. Examples of the magnetic metal material used for the peripheral wall (21a) of the bypass upstream water passage portion (21) include iron, steel, nickel, cobalt, and the like.

[0036] Two types of Specific Examples 2-1 and 2-2 of the iron foreign matter capturing device (20) shown in FIGS. 5(A) and (C) will be described. The iron foreign matter capturing devices (20) of Specific Examples 2-1 and 2-2 include a filter (23) for capturing iron foreign matter.

[0037] According to these two types of specific examples 2-1 and 2-2 of the iron foreign matter capturing device (20), before iron foreign matters such as iron rust generated in the main water channel (M) and the bypass water channel (B) shown in FIG. 1 enter the electric water pump (7), they are captured by the filter (23) of the iron foreign matter capturing device (20) on the upstream side of the bypass water channel (B). Therefore, the deposition and jamming of iron foreign matters in the electric water pump (7) can be prevented.

[0038] As shown in FIG. 5(A), the iron foreign matter capturing device (20) of the specific example 2-1 includes a flat filter (23a) that crosses the bypass upstream water channel portion (21) constituting the upstream side portion of the bypass water channel (B) as the filter (23).

[0039] The iron foreign matter capturing device (20) of the specific example 2-1 includes the bypass upstream water channel portion (21) and the flat filter (23a). The peripheral wall (21a) of the bypass upstream water channel portion (21) is made of rubber. The upstream end portion (21b) of the bypass upstream water channel portion (21) is connected to the thermo outlet (6a) of the thermostat housing (6), and the downstream end portion (21c) is connected to the cooling water inlet (7a) of the electric water pump (7). The flat filter (23a) is attached across the cooling water inlet (7a) of the electric water pump (7). The upstream end portion (21b) of the bypass upstream water channel portion (21) is detachably connected to the thermo outlet (6a) of the thermostat housing (6), and the downstream end portion (21c) is detachably connected to the cooling water inlet (7a) of the electric water pump (7). The iron foreign matter capturing device (20) can be removed from the bypass water channel (B) so that the iron foreign matter capturing device (20) can be cleaned and replaced.

[0040] As shown in FIG. 5(C), in the iron foreign matter capturing device (20) of the specific example 2-2, the filter (23) includes a cylindrical filter (23c) disposed in a filter case (23b) communicating with the bypass upstream water channel portion (21) constituting the upstream side portion of the bypass water channel (B).

[0041] As shown in FIG. 5(C), in the iron foreign matter capturing device (20) of Specific Example 2-2, the filter case (23b) is detachably attached to an attachment seat (24) that communicates with the bypass upstream water passage portion (21).

[0042] The attachment seat (24) is integrally formed with the bypass upstream water passage portion (21). The upstream end portion (21b) of the bypass upstream water passage portion (21) is connected to the thermo outlet (6a) of the thermostat housing (6) via a thermo outlet side tube (6b), and the downstream end portion (21c) communicates with the cooling water inlet (7a) of the electric water pump (7) via a water pump inlet side tube (7b). The upstream end portion (21b) of the bypass upstream water passage portion (21) is detachably connected to the thermo outlet side tube (6b), and the downstream end portion (21c) is detachably connected to the water pump inlet side tube (7b). The iron foreign matter capturing device (20) can be removed from the bypass water passage (B) so that the iron foreign matter capturing device (20) can be cleaned or replaced.

[0043] In this engine, as needed, among the three specific examples of the iron foreign matter capturing device (20) of Specific Examples 1, 2-1, and 2-2, any one type can be used alone, any two types can be used in plurality, or all three types can be used in plurality. When arranging Specific Examples 1 and 2-1 in series, or when arranging Specific Examples 1 and 2-2 in series, it is desirable to arrange Specific Example 1 on the upstream side of the flow path. The reason is as follows. Even if some of the iron foreign matter captured on the upstream side of the flow path by Specific Example 1 is discharged downstream by the water flow of the engine cooling water (5), it is re-captured by the filters (23) of Specific Examples 2-1 and 2-2 and will not be re-discharged. Therefore, the capturing performance of iron foreign matter is high, the iron foreign matter is not discharged to the electric water pump (7) or the downstream side thereof, and most of the iron foreign matter is captured by Specific Example 1 on the upstream side. The filters (23) of Specific Examples 2-1 and 2-2 on the downstream side are less likely to be clogged, so the service life of the filters (23) is prolonged.

[0044] The specific structure of the electric water pump (7) is as follows. As shown in Fig. 6(A), the electric water pump (7) is a centrifugal pump, and includes a pump housing (7c), a stator (7d), a rotor (7e), a pump chamber (7f), and an impeller (7g). A bypass upstream water passage portion (21) of the iron foreign matter trapping device (20) or a water pump inlet side tube (7b) connected to the downstream side of the iron foreign matter trapping device (20) is connected to the cooling water inlet (7a) of the pump chamber (7f), and a related component inlet side tube (7k) to each engine related component (P) is connected to the cooling water outlet (7h) of the pump chamber (7f). All the tubes in this embodiment are flexible, and both ends are removably connected to the outlets or inlets of the engine cooling water (5) and blow-by gas (10) of each component.

[0045] In this engine, without the iron foreign matter trapping device (20), iron foreign matters stagnate in the pump chamber (7f) due to the magnetic force of the stator (7d) and the rotor (7e), and the iron foreign matters adhere in the pump chamber (7f), or problems such as the iron foreign matters getting stuck in the gap between the pump chamber (7f) and the impeller (7g) or between the stator (7d) and the rotor (7e) are likely to occur. On the contrary, with the iron foreign matter trapping device (20), the iron foreign matters are trapped by the iron foreign matter trapping device (20) before flowing into the pump chamber (7f), so such problems are less likely to occur.

[0046] This engine includes an oil separator (49) shown in Fig. 6(B) and a PCV valve (50) shown in Fig. 6(C) as a blow-by gas reflux device (12). The PCV valve (50) is arranged on the upstream side of the blow-by gas reflux path (34) shown in Fig. 3(A), and the oil separator (49) is arranged on the downstream side of the blow-by gas reflux path (34).

[0047] As shown in FIG. 6(B), the oil separator (49) includes a separator housing (49a), a blow-by gas swirling chamber (49b), a cylindrical oil filter (49c), and an oil drain chamber (49d). The blow-by gas inlet (49e) of the blow-by gas swirling chamber (49b) is connected to the PCV valve outlet side tube (50a). The blow-by gas outlet (49ca) of the cylindrical oil filter (49c) is connected to the intake passage (11) via the blow-by gas outlet side tube (49cb). The oil outlet (49f) of the oil drain chamber (49d) communicates with the crankcase (9) via the oil outlet side tube (49g). The oil (10a) in the oil drain chamber (49d) returns to the oil pan 30 via the crankcase (9).

[0048] As shown in FIG. 6(B), the heat exchanger (49h) of the oil separator (49) is disposed below the oil drain chamber (49d). The water inlet (49ha) of the heat exchanger (49h) communicates with the cooling water outlet (7h) of the electric water pump (7). The water outlet (49hb) of the heat exchanger (49h) communicates with the cooling water inlet (4a) of the mechanical water pump (4).

[0049] In this engine, without the iron-based foreign matter capturing device (20), problems such as adhesion of iron-based foreign matter in the heat exchanger (49h) are likely to occur. On the other hand, with the iron-based foreign matter capturing device (20), the iron-based foreign matter is captured by the iron-based foreign matter capturing device (20) before flowing into the heat exchanger (49h), so such problems are less likely to occur.

[0050] As shown in FIG. 6(C), the PCV valve (50) includes a valve housing (50g), a valve body (50b), and a valve spring (50c). The blow-by gas inlet (50d) of the valve housing (50g) communicates with the cylinder head cover (27). The blow-by gas outlet (50e) of the valve housing (50g) communicates with the blow-by gas swirling chamber (49b) of the oil separator (49) via the PCV valve outlet side tube (50a).

[0051] As shown in Fig. 6(C), the heat exchanger (50f) of the PCV valve (50) is disposed below the valve housing (50g). The water inlet (50fa) of the heat exchanger (50f) communicates with the cooling water outlet (7h) of the electric water pump (7), and the water outlet (50fb) of the heat exchanger (50f) communicates with the cooling water inlet (4a) of the mechanical water pump (4).

[0052] In this engine, without the iron-based foreign matter capturing device (20), problems such as adhesion of iron-based foreign matter in the heat exchanger (50f) are likely to occur. On the contrary, with the iron-based foreign matter capturing device (20), the iron-based foreign matter is captured by the iron-based foreign matter capturing device (20) before flowing into the heat exchanger (50f), so such problems are less likely to occur.

[0053] The specific structure of the urea water injector (16) is as follows. As shown in Fig. 6(D), the urea water injector (16) includes an injector housing (16b), an electromagnetic solenoid (16c), and a nozzle portion (16d).

[0054] As shown in Fig. 6(D), the heat exchanger (16a) of the urea water injector (16) is formed around the nozzle portion (16d). The water inlet (16aa) of the heat exchanger (16a) is connected to the cooling water outlet (7h) of the electric water pump (7), and the water outlet (16ab) of the heat exchanger (16a) is connected to the cooling water inlet (4a) of the mechanical water pump (4).

[0055] In this engine, when there is no iron-based foreign matter capturing device (20), iron-based foreign matter stagnates in the heat exchanger (16a) due to the magnetic force of the electromagnetic solenoid (16c), and problems such as adhesion of iron-based foreign matter in the heat exchanger (16a) or jamming of iron-based foreign matter in the gaps within the heat exchanger (16a) are likely to occur. On the contrary, when there is an iron-based foreign matter capturing device (20), the iron-based foreign matter is captured by the iron-based foreign matter capturing device (20) before flowing into the heat exchanger (16a), so such problems are less likely to occur.

[0056] The specific structure of the urea water tank (17) is as follows. As shown in Fig. 7, the aqueous urea (15) stored in the aqueous urea tank (17) is supplied to the aqueous urea injector (16) via the aqueous urea pump (17d). A U-shaped heat exchanger (17a) is arranged in the aqueous urea tank (17). The water inlet (17aa) of the heat exchanger (17a) communicates with the cooling water outlet (7h) of the electric water pump (7) via the electric valve (17b), and the water outlet (17ab) of the heat exchanger (17a) communicates with the cooling water inlet (4a) of the mechanical water pump (4).

[0057] In this engine, without the iron-based foreign matter capturing device (20), iron-based foreign matter is likely to stagnate in the electric valve (17b) due to the magnetic force of the electric valve (17b), the iron-based foreign matter may adhere in the electric valve (17b), or the iron-based foreign matter may get stuck in the gap in the electric valve (17b). On the contrary, with the iron-based foreign matter capturing device (20), the iron-based foreign matter is captured by the iron-based foreign matter capturing device (20) before flowing into the electric valve (17b), so such problems are less likely to occur.

[0058] The specific structure of the air conditioner (18) is as follows. As shown in Fig. 8, the air conditioner (18) is arranged in the cabin (19) and includes a heat exchanger (18a) and an electric fan (18d). The water inlet (18aa) of the heat exchanger (18a) communicates with the cooling water outlet (7h) of the electric water pump (7), and the water outlet (18ab) of the heat exchanger (18a) communicates with the cooling water inlet (4a) of the mechanical water pump (4). Also, the solenoid valve (18b) for opening and closing the water passage of the heat exchanger (18a) is arranged inside the air conditioner (18).

[0059] In this engine, without the iron-based foreign matter capturing device (20), iron-based foreign matter is likely to stagnate in the heat exchanger (18a) due to the magnetic force of the motor (8e) of the electric fan (18d), the iron-based foreign matter may adhere in the heat exchanger (18a), or the iron-based foreign matter may get stuck in the gap in the heat exchanger (18a). On the contrary, with the iron-based foreign matter capturing device (20), the iron-based foreign matter is captured by the iron-based foreign matter capturing device (20) before flowing into the heat exchanger (18a), so such problems are less likely to occur. Also, in this engine, without the iron foreign object capturing device (20), iron foreign objects may stagnate inside the solenoid valve (18b) due to the magnetic force of the solenoid valve (18b), the iron foreign objects may adhere inside the solenoid valve (18b), or the iron foreign objects may bite into the gaps inside the solenoid valve (18b), etc. are likely to occur. On the contrary, with the iron foreign object capturing device (20), the iron foreign objects are captured by the iron foreign object capturing device (20) before flowing into the solenoid valve (18b), so such problems are less likely to occur.

[0060] In this engine, as needed, as engine-related parts (P), one or more selected from the oil separator (49) of the blow-by gas (10) shown in FIGS. 6(B) to (D), the PCV valve (50), the blow-by gas recirculation passage (51), the urea water injector (16), the urea water tank (17) shown in FIG. 7, and the air conditioner (18) shown in FIG. 8 can be used.

Explanation of Signs

[0061] (1)…Engine body, (2)…Radiator, (3)…Crankshaft, (4)…Mechanical water pump, (5)…Engine cooling water, (5a)…Water temperature sensor, (M)…Main waterway, (7)…Electric water pump, (B)…Bypass waterway, (9)…Crankcase, (10)…Blow-by gas, (10a)…Oil, (11)…Intake path, (12)…Blow-by gas recirculation device, (12a)…Heat exchanger, (13)…Electronic control device, (14)…Exhaust, (15)…Urea water, (16)…Urea water injector, (16a)…Heat exchanger, (17)…Urea water tank, (17a)…Heat exchanger, (17b)…Electric valve, (17c)…Urea water temperature sensor, (18)…Air conditioner, (18a)…Heat exchanger, (18b)…Solenoid valve, (18c)…Operation switch, (19)…Cabin, (19a)…Room temperature setting device, (19b)…Room temperature sensor, (49)…Oil separator, (49h)…Heat exchanger, (50)…PCV valve, (50f)…Heat exchanger, (51)…Blow-by gas recirculation passage.

Claims

1. An engine body (1), a radiator (2), a mechanical water pump (4) driven by a crankshaft (3), a main water passage (M) for circulating engine cooling water (5) between the engine body (1) and the radiator (2) by the mechanical water pump (4) to cool the engine body (1), engine-related components (P), a heat exchanger (Pa) of the engine-related components (P), an electric water pump (7), and a bypass water passage (B) for circulating engine cooling water (5) between the main water passage (M) and the heat exchanger (Pa) of the engine-related components (P) by the electric water pump (7), wherein, as the engine-related components (P), a blow-by gas reflux device (12) for refluxing blow-by gas (10) in a crankcase (9) to an intake passage (11) is provided, and the blow-by gas reflux device (12) is configured to be heated by engine cooling water (5) passing through a heat exchanger (12a) of the blow-by gas reflux device (12). An engine characterized by this.

2. The engine according to claim 1, wherein, as the blow-by gas reflux device (12), an oil separator (49) for separating oil (10a) from the blow-by gas (10) is provided, and the oil separator (49) is configured to be heated by engine cooling water (5) passing through a heat exchanger (49h) of the oil separator (49). An engine characterized by this.

3. The engine according to claim 1, wherein, as the blow-by gas reflux device (12), a PCV valve (50) and / or a blow-by gas reflux passage (51) are provided, and the PCV valve (50) and / or the blow-by gas reflux passage (51) are configured to be heated by engine cooling water (5) passing through a heat exchanger (50f) of the PCV valve (50) and / or the blow-by gas reflux passage (51). An engine characterized by this.

4. The engine according to claim 1, comprising an electronic control unit (13), wherein the driving of the electric water pump (7) is controlled by the electronic control unit (13), and the target rotational speed of the electric water pump (7) is configured to be maintained at a predetermined constant value. An engine characterized by this.

5. The engine according to claim 1, comprising a water temperature sensor (5a) for detecting the temperature of the engine cooling water (5) and an electronic control unit (13). The driving of the electric water pump (7) is controlled by an electronic control unit (13), and the rotational speed of the electric water pump (7) increases as the temperature of the engine cooling water (5) detected by the water temperature sensor (5a) decreases. An engine characterized by this.

6. In the engine according to claim 1, As an engine-related component (P), it is provided with a urea water injector (16) for injecting urea water (15) into the exhaust gas (14), and the urea water injector (16) is cooled by the engine cooling water (5) passing through the heat exchanger (16a) of the urea water injector (16). An engine characterized by this.

7. In the engine according to claim 1, As an engine-related component (P), it is provided with a urea water tank (17), and the urea water (15) in the urea water tank (17) is heated by the engine cooling water (5) passing through the heat exchanger (17a) of the urea water tank (17). An engine characterized by this.

8. In the engine according to claim 7, It includes an electric valve (17b) for opening and closing the flow path of the engine cooling water (5) passing through the heat exchanger (17a) of the urea water tank (17), a urea water temperature sensor (17c) for detecting the temperature of the urea water (15) in the urea water tank (17), and an electronic control unit (13). The electric valve (17b) is controlled to open and close by the electronic control unit (13). When the urea water temperature detected by the urea water temperature sensor (17c) is in a heating required state below a predetermined threshold value, the electric valve (17b) is in an open valve state. When the urea water temperature detected by the urea water temperature sensor (17c) is in a heating not required state exceeding the predetermined threshold value, the electric valve (17b) is in a closed valve state. An engine characterized by this.

9. In the engine according to claim 1, As an engine-related component (P), it is provided with an air conditioner (18), and the air in the cabin (19) where the air conditioner (18) is installed is heated by the engine cooling water (5) passing through the heat exchanger (18a) of the air conditioner (18). An engine characterized by this.

10. In the engine according to claim 9, An engine, comprising a solenoid valve (18b) for opening and closing a flow path of engine cooling water (5) passing through a heat exchanger (18a) of an air conditioner (18), and an operation switch (18c) for operating the air conditioner (18), wherein when the operation switch (18c) is turned on to the operating position, the solenoid valve (18b) is opened, and when the operation switch (18c) is turned on to the operation stop position, the solenoid valve (18b) is closed.

11. In the engine according to claim 10, an electronic control unit (13), a room temperature setting device (19a) for setting a target room temperature in a cabin (19) where the air conditioner (18) is installed, a room temperature sensor (19b) for detecting the room temperature in the cabin (19), a water temperature sensor (5a) for detecting the temperature of the engine cooling water (5), and an electronic control unit (13) are provided. When the operation switch (18c) of the air conditioner (18) is turned on to the operating position, the opening degree of the solenoid valve (18b) is adjusted based on the set room temperature set by the room temperature setting device (19a), the detected room temperature detected by the room temperature sensor (19b), and the water temperature detected by the water temperature sensor (5a) for detecting the water temperature of the engine cooling water (5) under the control of the electronic control unit (13), so that the room temperature in the cabin (19) approaches the set temperature.

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