JP2017067022A - Breather device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breather device of an engine which prevents blockage caused by moisture freezing in a breather box.SOLUTION: In a breather device of an engine, a cylinder head 1 is covered by a cylinder head cover 2 and a breather box 3 is attached along a head cover ceiling wall 2a of the cylinder head cover 2. A box ceiling wall 3a of the breather box 3 is made of a synthetic resin and is separated from the head cover ceiling wall 2a of the cylinder head cover 2. The breather box 3 includes a separate liquid drain pipe 22. The separate liquid drain pipe 22 is led out downward from the breather box 3 toward the cylinder head 1. A separate liquid drain port 22a opens at a lower end part of the separate liquid drain pipe 22.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an engine breather device, and more particularly to an engine breather device capable of preventing clogging due to freezing of moisture in a breather box.

  2. Description of the Related Art Conventionally, there is an engine breather device in which a cylinder head is covered with a cylinder head cover and a breather box is attached along a head cover ceiling wall of the cylinder head cover (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-81974 (see FIG. 1)

<< Problem >> Blockage due to freezing of water in the breather box is likely to occur.
In Patent Document 1, if the engine is stopped for a short time after the engine has been cold-started, the breather box is likely to be clogged due to water freezing, and the internal pressure of the crank chamber increases when the engine is restarted. Oil may leak from the oil seal.
The reason is considered as follows.
In Patent Document 1, since the box ceiling wall of the breather box is made of iron, when the head cover ceiling wall of the cylinder head cover is cooled by outside air, the blow-by gas in the breather box is cooled through the box ceiling wall, and the breather Clogging due to freezing of water in the box is likely to occur.

  The subject of this invention is providing the breather apparatus of the engine which can prevent the obstruction | occlusion by freezing of the water | moisture content in a breather box.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIGS. 2B, 3A, and 7 to 10, the cylinder head 1 is covered with the cylinder head cover 2 and the head cover ceiling wall 2a of the cylinder head cover 2 is provided. In the breather device of the engine with the breather box (3) attached along
As illustrated in FIGS. 2B, 3A, and 7 to 10, the box ceiling wall (3a) of the breather box (3) is made of synthetic resin and the head cover ceiling of the cylinder head cover (2). Away from the wall (2a),
As illustrated in FIGS. 3A and 7 to 10, the breather box (3) includes a separation liquid drain pipe (22), and the separation liquid drain pipe (22) extends from the breather box (3) to the cylinder head ( 1. A breather device for an engine, which is led downward toward 1) and has a separation liquid drain port (22a) opened at a lower end portion of the separation liquid drain pipe (22).

(Invention of Claim 1)
The invention according to claim 1 has the following effects.
<Effect> It is possible to prevent clogging due to freezing of water in the breather box.
3A and 7 to 10, the box ceiling wall (3a) of the breather box (3) is made of synthetic resin and is separated from the head cover ceiling wall (2a) of the cylinder head cover (2). Therefore, even if the head cover ceiling wall (2a) is cooled by outside air, the blow-by gas in the breather box (3) is not easily cooled. For this reason, the moisture contained in the blow-by gas is difficult to freeze in the breather box (3), and blockage due to the freezing of moisture in the breather box (3) can be prevented.

<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port.
As illustrated in FIGS. 3A and 7 to 10, the separation liquid drain pipe (22) is led downward from the breather box (3) toward the cylinder head (1), and the separation liquid drain pipe (22 The separation liquid drain port (22a) is opened at the lower end of the separation liquid drain port (22a), so that even if the head cover ceiling wall (2a) is cooled by outside air, the separation liquid drain port (22a) is difficult to be cooled. Blockage due to freezing of water in 22a) is unlikely to occur.

(Invention of Claim 2)
The invention according to claim 2 has the following effect in addition to the effect of the invention according to claim 1.
<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port and the separation liquid reservoir recess.
As illustrated in FIGS. 3A and 7 to 10, the cylinder head (1) includes a separation liquid reservoir recess (23), and the separation liquid (24) stored in the separation liquid reservoir recess (23) Since the separation liquid drain port (22a) is immersed, even if the separation liquid (24) accumulates in the separation liquid reservoir recess (23) or the separation liquid drain port (22a) during engine operation, the separation liquid (24) After the engine is stopped, the moisture contained in the water evaporates due to the residual heat of the cylinder head and hardly stays in the separation liquid reservoir recess (23) or the separation liquid drain port (22a). It is possible to prevent clogging due to water freezing in 23).

(Invention of Claim 3)
The invention according to claim 3 has the following effect in addition to the effect of the invention according to claim 2.
<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port and the separation liquid reservoir recess.
As illustrated in FIG. 7, since the breather box (3) is supported by the cylinder head cover (2) via the elastic body (25), after the engine is stopped, the separation liquid drain port (22a) and the separation liquid reservoir recess are formed. Even if the water contained in the separation liquid (24) is frozen in (23), when the separation liquid drain pipe (22) vibrates together with the breather box (3) via the elastic body (25) when the engine is restarted, the separation liquid The water frozen in the drain port (22a) and the separation liquid reservoir recess (23) is crushed by the vibration of the separation liquid drain pipe (22), and the water is frozen in the separation liquid drain port (22a) and the separation liquid reservoir recess (23). Blockage due to can be prevented.

(Invention of Claim 4)
The invention according to claim 4 has the following effect in addition to the effect of the invention according to claim 2 or claim 3.
<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port and the separation liquid reservoir recess.
Since molybdate is contained in the separation liquid reservoir recess (23), even if the separation liquid (24) is accumulated in the separation liquid drain port (22a) or the separation liquid reservoir recess (23), the separation liquid (24) Molybdate is dissolved in the water, and the freezing point of the water is increased. Even after the engine is stopped, it is possible to prevent clogging due to water freezing at the separation liquid drain port (22a) and the separation liquid reservoir recess (23).

(Invention according to claim 5)
The invention according to claim 5 has the following effect in addition to the effects of the invention according to claims 2 to 4.
<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port and the separation liquid reservoir recess.
As illustrated in FIGS. 3A and 7 to 10, the separation liquid reservoir recess 23 is constituted by a metal saddle plug 27, and the coolant plug 26 is formed by the saddle plug 27. ) Is closed, even if the separation liquid (24) accumulates in the separation liquid drain port (22a) or the separation liquid reservoir recess (23) during engine operation, the separation liquid (24) After the engine is stopped, the water contained in the water evaporates due to the residual heat of the engine cooling water in the cylinder head (1) and the cooling water jacket (26) conducted by the saddle plug (27), and the separation liquid drain port (22a) It is difficult to stay in the separation liquid reservoir recess (23), and blockage of the separation liquid drain port (22a) and the separation liquid reservoir recess (23) due to freezing of water can be prevented.

(Invention of Claim 6)
The invention according to claim 6 has the following effect in addition to the effect of the invention according to claim 5.
<Effect> It is possible to prevent clogging due to water freezing in the separation liquid drain pipe.
As illustrated in FIGS. 8 and 9, since the heat conductor (23a) is led out from the inner bottom surface of the separation liquid reservoir recess (23) to the lower end of the separation liquid drain pipe (22), Even if the separation liquid (24) accumulates in the separation liquid drain pipe (22), the water contained in the separation liquid (24) is transferred to the cylinder head (1) after being stopped by the heat conduction rod (23a) after the engine is stopped. The cylinder head (1) and the cooling water jacket (26) evaporate due to the remaining heat of the engine cooling water, and blockage of the separated liquid drain pipe (22) due to water freezing can be prevented.

(Invention of Claim 7)
The invention according to claim 7 has the following effect in addition to the effect of the invention according to claim 6.
<Effect> Large amount of heat input to heat conductor.
As illustrated in FIG. 9, since the heat input part (23b) of the heat conductor (23a) is led out to the exhaust port wall (27), the amount of heat input to the heat conductor (23a) is large.

(Invention of Claim 8)
The invention according to claim 8 has the following effects in addition to the effects of the inventions according to claims 1 to 7.
<Effect> It is possible to prevent clogging due to water freezing at the separation liquid drain port and the separation liquid reservoir recess.
As illustrated in FIG. 10, since the breather box (3) includes a heater (28), the separation liquid (24) is placed in the separation liquid drain port (22a) and the separation liquid reservoir recess (23) during engine operation. Even if accumulated, the water contained in the separated liquid (24) evaporates due to the heat of the heater (28) after the engine is stopped, and hardly stays in the separated liquid drain port (22a) or the separated liquid reservoir recess (23). It is possible to prevent clogging due to water freezing at the liquid drain port (22a) and the separation liquid reservoir recess (23).

It is a perspective view of the breather device of the engine concerning the embodiment of the present invention. 2A is a cross-sectional view taken along line AA of FIG. 2B, FIG. 2B is a cross-sectional view taken along line BB of FIG. 2A, and FIG. (C) is an expanded sectional view of a reed valve and its surrounding part. FIG. 3A is a diagram illustrating a basic example and a modification of the head cover of the apparatus of FIG. 1, and FIG. FIG. 4A is a diagram for explaining a modification of the blow-by gas discharge passage, FIG. 4A is a modification 1, FIG. 4B is a cross-sectional view taken along the line BB of FIG. 4A, and FIG. 2 and FIG. 4D show a third modification. FIGS. 5A and 5B illustrate a modification of the blow-by gas discharge passage. FIG. 5A illustrates a modification 4 and FIG. It is a figure explaining the modification 6 of a blowby gas discharge passage. It is a figure explaining the modification 1 of a separation liquid drain. It is a figure explaining the modification 2 of a separation liquid drain. It is a figure explaining the modification 3 of a separation liquid drain. It is a figure explaining the modification 4 of a separation liquid drain.

  FIGS. 1-10 is a figure explaining the engine which concerns on embodiment of this invention, and this embodiment demonstrates the breather apparatus of a vertical in-line 2 cylinder diesel engine.

  As shown in FIG. 2B, in this engine breather device, the cylinder head (1) is covered with a cylinder head cover (2), and a breather box (2) is formed along the head cover ceiling wall (2a) of the cylinder head cover (2). 3) is attached.

As shown in FIG. 2B, the box ceiling wall (3a) of the breather box (3) is made of synthetic resin and is separated from the head cover ceiling wall (2a) of the cylinder head cover (2).
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air, the blow-by gas in the breather box (3) is hardly cooled. Thereby, the moisture contained in the blow-by gas is hardly frozen in the breather box (3), and blockage due to the freezing of moisture in the breather box (3) can be prevented.
The cylinder head cover (2) is made of aluminum die casting.
The breather box (3) is entirely made of synthetic resin, and nylon and other synthetic resins can be used.

As shown in FIG. 2B, the breather box (3) includes a blow-by gas inlet chamber (4), a blow-by gas relay chamber (5), a blow-by gas outlet chamber (6), and a separation liquid drain chamber (7). The blow-by gas relay chamber (5) is provided between the blow-by gas inlet chamber (4) and the breather outlet chamber (6).
As shown in FIG. 2B, the separation liquid drain chamber (7) is formed below the blow-by gas relay chamber (5).
For this reason, when the moisture contained in the blowby gas is condensed in the blowby gas relay chamber (5), it is quickly discharged from the separation liquid drain chamber (7). Thereby, the moisture contained in the blow-by gas is hardly frozen in the breather box (3), and blockage due to the freezing of moisture in the breather box (3) can be prevented.

As shown in FIG. 2 (B), the longitudinal direction of the cylinder head cover (2) is the longitudinal direction, the breather box (3) is formed long in the longitudinal direction, and the blow-by gas inlet chamber (4) is formed in the breather box (3). The blow-by gas outlet chamber (6) is provided at one end in the front-rear direction, and is provided at the other end in the front-rear direction of the breather box (3).
As shown in FIG. 2 (B), the cylinder head (1) is provided with a rocker arm (8), and the peripheral wall of the separation liquid drain chamber (7) is the rocker arm (8) on the blow-by gas outlet chamber (6) side and the blow-by gas inlet. It protrudes downward from the box bottom wall (3b) of the breather box (3) toward the space between the chambers (4).
For this reason, the blow-by gas below the blow-by gas outlet chamber (6) is obstructed from moving toward the blow-by gas inlet chamber (4) by the peripheral wall of the separation liquid drain chamber (7), and close to the blow-by gas outlet chamber (6). The rocker arm (8) swings against the bottom wall of the blow-by gas outlet chamber (6), and the separated liquid containing water and oil is separated from the blow-by gas and blow-by gas to the blow-by gas inlet chamber (4) is separated. Intrusion of moisture is hindered.

As shown in FIG. 2A, the breather box (3) includes a boundary wall (9), a separation liquid outflow gap (10), and a separation liquid guide groove (11), and the boundary wall (9) is a blow-by gas inlet chamber. (4) is provided at the boundary between the blow-by gas relay chamber (5), the separation liquid outflow gap (10) is provided at the lateral end of the boundary wall (9), and the separation liquid guide groove (11) is provided at the blow-by gas inlet. It is led out from the chamber (4) to the separation liquid drain chamber (7) through the separation liquid outflow gap (10).
For this reason, the separation liquid consisting of water and oil separated from the blow-by gas in the blow-by gas inlet chamber (4) flows into the separation liquid drain chamber (7) through the separation liquid guide groove (11), and quickly enters the breather box ( 3) The separated liquid is not easily collected in the blow-by gas inlet chamber (4).

As shown in FIG. 2 (C), the breather box (3) includes a valve presser (12), a reed valve (13), and a blow-by gas inlet (14). The valve presser (12) is made of a synthetic resin, It protrudes downward from the ceiling wall (3a), the fixed end (13a) of the reed valve (13) is pressed and fixed to the box bottom wall (3b) by the valve retainer (12), and the blow-by gas inlet (14) It opens to the bottom wall (3b) and is covered with the free end (13b) of the reed valve (13) from above.
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air, the valve retainer (12) and the reed valve (13) are not easily cooled.

The reed valve (13) is also made of synthetic resin.
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air, the reed valve (13) is not easily cooled.
As shown in FIG. 2 (C), the reed valve (13) includes a bending boundary ridge (13c) and a weight portion (13d), and the bending boundary ridge ( 13c) traverses the portion of the reed valve (13) near the valve retainer (12) in the lateral direction and is curved in an upward projecting arc shape when viewed from the side, and the weight portion (13d) is reed valve (13). Is provided at the free end (13b).
For this reason, the reed valve (13) is easily bent greatly from the bending boundary ridge (13c), and the swing of the reed valve (13) is blown against the reed valve (13) due to the stationary inertia of the weight. The blow-by gas is strongly struck against the surface of the reed valve (13), and the separation function of the separation liquid by the reed valve (13) is enhanced.
A metal such as spring steel can be used for the reed valve (13).

As shown in FIGS. 2A to 2C, the breather box (3) includes a blow-by gas inlet (14), and the blow-by gas inlet (14) includes a water-repellent netting material.
For this reason, part of the moisture contained in the blow-by gas is repelled by the water-repellent netting material at the blow-by gas inlet (14) and does not enter the breather box (3) but is contained in the blow-by gas passing through the breather box (3). The water content is reduced, and blockage due to freezing of water in the breather box (3) can be prevented.
The breather box (3) includes a blow-by gas outlet (15), and the blow-by gas outlet (15) includes a water-repellent netting material.
For this reason, a part of the water contained in the blow-by gas is repelled by the water-repellent netting material and does not enter the blow-by gas outlet (15), thereby preventing clogging due to freezing of water at the blow-by gas outlet (15). it can.

In this embodiment, a modification shown in FIG. 3B can be used as a modification of the cylinder head cover (2).
In this modification, unlike the basic example of FIG. 3A, the cylinder head cover (2) includes an air chamber (2c), and the air chamber (2c) covers the breather box (3) from above. ).
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air, the blow-by gas in the breather box (3) is not easily cooled by the heat insulating action of the air chamber (2c).
The cylinder head cover (2) is provided with a heat insulating coating (2d), and the heat insulating coating (2d) is formed on the inner surface of the head cover ceiling wall (2a) covering the breather box (3) from above. Contains heat insulating air bubbles.
Even if the head cover ceiling wall (2a) is cooled by outside air, the blow-by gas in the breather box (3) is hardly cooled by the heat insulating action of the heat insulating coating (2d).

As shown in FIGS. 2 (B) and 3 (A), the box ceiling wall (3a) of the breather box (3) is made of synthetic resin and is separated from the head cover ceiling wall (2a) of the cylinder head cover (2). The blow-by gas discharge passage (16) is provided in the head cover ceiling wall (2a) along the box ceiling wall (3a).
For this reason, it is possible to prevent the overall height of the engine from being increased in the blow-by gas discharge passage (16).

The blow-by gas discharge passage (16) can be modified as follows.
In the basic example of FIG. 3 (A), the inner bottom surface (16a) of the blow-by gas discharge passage (16) is horizontal, but in the first modification shown in FIGS. 4 (A) and (B), the blow-by gas discharge passage ( The inner bottom surface (16a) of 16) is inclined downward toward the blow-by gas discharge direction.
For this reason, even if moisture contained in the blow-by gas is condensed in the blow-by gas discharge passage (16), after the engine is stopped, the water flows out in the blow-by gas discharge direction by its own weight and hardly stays in the blow-by gas discharge passage (16). Further, it is possible to prevent clogging due to freezing of moisture in the blow-by gas discharge passage (16).

4 (A) and 4 (B), the blow-by gas discharge passage (16) includes a separation liquid guide groove (16b), and the separation liquid guide groove (16b) is included in the blow-by gas discharge passage (16). It is provided on the bottom surface (16a) and is inclined downward toward the blow-by gas discharge direction.
For this reason, even if the moisture contained in the blowby gas is condensed in the blowby gas discharge passage (16), the moisture is concentrated in the separation liquid guide groove (16b) and flows out in the blowby gas discharge direction by its own weight after the engine is stopped. It is difficult to stay in the blow-by gas discharge passage (16), and blockage due to freezing of water in the blow-by gas discharge passage (16) can be prevented.

In the second modification shown in FIG. 4C, a blow-by gas discharge extension tube (17) is provided, the blow-by gas discharge passage (16) is provided with an outlet tube (18) and an annular recess (19), and an outlet tube (18 ) Protrudes from the head cover ceiling wall (2a), and the annular recess (19) is recessed in the head cover ceiling wall (2a) around the outlet tube (18), and is connected to the tube inlet (17) of the blow-by gas discharge extension tube (17). 17a) is externally fitted to the outlet tube (18) in the annular recess (19).
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air after the engine is stopped, the outlet cylinder (18) whose outer periphery is covered by the tube inlet (17a) is hardly cooled by the heat insulating action of the tube inlet (17a). Further, it is possible to prevent clogging due to freezing of moisture in the blow-by gas discharge passage (16).

4 (D) includes a blow-by gas discharge extension tube (17), the blow-by gas discharge passage (17) includes an outlet pipe (20) and an annular recess (19), and the outlet pipe (20). Projecting from the head cover ceiling wall (2a), the annular recess (19) is recessed in the head cover ceiling wall (2a) around the outlet pipe (20), and the tube inlet (17a) of the blow-by gas discharge extension tube (17) is provided. ) Is externally fitted to the outlet pipe (20), the opening of the annular recess (19) is closed at the tube inlet (17a), and the inside of the annular recess (19) is an air reservoir.
For this reason, the outlet pipe (20) whose outer side is covered with the annular recess (19) is difficult to be cooled by the heat insulating action of the annular recess (19), and prevents blockage due to freezing of water in the blow-by gas discharge passage (16). can do.
A thick heat insulating layer (17b) is provided on the outer periphery of the blow-by gas discharge extension tube (17). For this heat insulation layer (17b), urethane foam or the like can be used.

In the modified example 4 shown in FIG. 5A, the heater (21) faces the blow-by gas discharge passage (16).
For this reason, if the heater (21) is heated after the engine is stopped, the blowby gas discharge passage (16) is difficult to be cooled even if the head cover ceiling wall (2a) is cooled by outside air after the engine is stopped. It is possible to prevent clogging due to freezing of water within 16).
In the fifth modification shown in FIG. 5B, the blow-by gas discharge passage (16) passes through the cylinder head (1).
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air after the engine is stopped, the blow-by gas discharge passage (16) is hardly cooled by the residual heat of the cylinder head (1), and the blow-by gas discharge passage (16) is not cooled. Blockage due to freezing of moisture can be prevented.

  In the modification shown in FIG. 6, a plurality of blow-by gas discharge passages (16) are provided. For this reason, the risk of water freezing in the blow-by gas discharge passage (16) is dispersed at a plurality of locations, and blockage due to water freezing in the blow-by gas discharge passage (16) can be prevented.

As shown in FIGS. 3A and 7 to 10, the breather box (3) includes a separation liquid drain pipe (22), and the separation liquid drain pipe (22) extends from the breather box (3) to the cylinder head (1). ) And a separation liquid drain port (22a) is opened at the lower end of the separation liquid drain pipe (22).
For this reason, even if the head cover ceiling wall (2a) is cooled by outside air, the separation liquid drain port (22a) is hardly cooled, and blockage due to freezing of water at the separation liquid drain port (22a) hardly occurs.

As shown in FIGS. 3A and 7 to 10, the cylinder head (1) is provided with a separation liquid reservoir recess (23), and is separated into a separation liquid (24) stored in the separation liquid reservoir recess (23). The liquid drain port (22a) is immersed.
For this reason, even when the separation liquid (24) accumulates in the separation liquid reservoir recess (23) or the separation liquid drain port (22a) during engine operation, the water contained in the separation liquid (24) It evaporates due to the residual heat of the head and does not stay in the separation liquid reservoir recess (23) or the separation liquid drain port (22a), and prevents clogging due to water freezing in the separation liquid drain port (22a) or the separation liquid reservoir recess (23). be able to.

The separation liquid drain can be modified as follows.
In the basic example shown in FIG. 3 (A), the breather box (3) is fixed to the cylinder head cover (2) with rivets or bolts. In the first modification shown in FIG. 7, the breather box (3) is attached to the cylinder head cover (2 ) Through an elastic body (25).
For this reason, after the engine is stopped, even if the water contained in the separation liquid (24) freezes at the separation liquid drain port (22a) or the separation liquid reservoir recess (23), the elastic body (25) passes through the elastic body (25) when the engine is restarted. When the separation liquid drain pipe (22) vibrates together with the breather box (3), the water frozen at the separation liquid drain port (22a) and the separation liquid reservoir recess (23) is crushed by the vibration of the separation liquid drain pipe (22). It is possible to prevent clogging due to water freezing at the separation liquid drain port (22a) and the separation liquid reservoir recess (23).
The elastic body (25) is adjusted so that the breather box (3) resonates at a predetermined engine speed.

Molybdate can be placed in the separation liquid reservoir recess (23).
For this reason, even if the separation liquid (24) accumulates in the separation liquid drain port (22a) or the separation liquid reservoir recess (23), molybdate is dissolved in the water of the separation liquid (24), and the freezing point of the water rises. Even after the engine is stopped, it is possible to prevent the separation liquid drain port (22a) and the separation liquid reservoir recess (23) from being blocked by water freezing. Molybdate has an antirust function.

In the basic example shown in FIG. 3 (A), the cylinder head (1) is provided with a cooling water jacket (26), and the separation liquid reservoir recess (23) is composed of a metal bowl-shaped plug (27). In (27), the opening (26a) of the cooling water jacket (26) is closed.
Therefore, even if the separation liquid (24) is accumulated in the separation liquid drain port (22a) or the separation liquid reservoir recess (23) during engine operation, the water contained in the separation liquid (24) The cylinder head (1) and the cooling water jacket (26) conducted by the plug (27) evaporate due to the remaining heat of the engine cooling water, and it is difficult to stay in the separation liquid drain port (22a) or the separation liquid reservoir recess (23). It is possible to prevent clogging due to water freezing at the separation liquid drain port (22a) and the separation liquid reservoir recess (23).

8 and 9, the separation liquid reservoir recess (23) includes a heat conductor (23a), and the heat conductor (23a) is separated from the inner bottom surface of the separation liquid reservoir recess (23). The liquid drain pipe (22) is led out into the lower end portion.
For this reason, even if the separation liquid (24) accumulates in the separation liquid drain pipe (22) during engine operation, the water contained in the separation liquid (24) is conducted by the heat conduction tank (23a) after the engine is stopped. The cylinder head (1) of the cylinder head (1) and the cooling water jacket (26) evaporate due to the remaining heat of the engine cooling water, thereby preventing the clogging of the separated liquid drain pipe (22) due to water freezing.

Furthermore, in the third modification shown in FIG. 9, the heat input portion (23b) of the heat conductor (23a) is led out to the exhaust port wall (27).
For this reason, the amount of heat input to the heat conductor (23a) is large.

In the fourth modification shown in FIG. 10, the breather box (3) includes a heater (28). For this reason, even if the separation liquid (24) accumulates in the separation liquid drain port (22a) or the separation liquid reservoir recess (23) during engine operation, the water contained in the separation liquid (24) It evaporates with the heat of (28) and hardly stays in the separation liquid drain port (22a) or the separation liquid reservoir recess (23), and is blocked by freezing of water in the separation liquid drain port (22a) or the separation liquid reservoir recess (23). Can be prevented.
The basic example and each modification can be freely combined. In the drawings of the respective modifications, the same elements as those of the basic example are denoted by the same reference numerals.

(1) Cylinder head
(2) Cylinder head cover
(2a) Head cover ceiling wall
(22) Separation liquid drain pipe
(22a) Separation liquid drain port
(23) Recessed liquid reservoir recess
(23a) Thermal conductor
(24) Separation liquid
(25) Elastic body
(26) Cooling water jacket
(26a) Opening
(27) Vertical plug
(28) Heater

Claims (8)

In an engine breather apparatus in which a cylinder head (1) is covered with a cylinder head cover (2) and a breather box (3) is attached along a head cover ceiling wall (2a) of the cylinder head cover (2).
The box ceiling wall (3a) of the breather box (3) is made of synthetic resin and is separated from the head cover ceiling wall (2a) of the cylinder head cover (2).
The breather box (3) includes a separation liquid drain pipe (22), and the separation liquid drain pipe (22) is led out downward from the breather box (3) toward the cylinder head (1), and the separation liquid drain pipe (22). A breather device for an engine, wherein a separation liquid drain port (22a) is opened at a lower end of the engine. The breather apparatus for an engine according to claim 1,
The cylinder head (1) includes a separation liquid reservoir recess (23), and a separation liquid drain port (22a) is immersed in the separation liquid (24) stored in the separation liquid reservoir recess (23). The breather device for the engine. The breather apparatus for an engine according to claim 2,
A breather device for an engine, characterized in that the breather box (3) is supported on the cylinder head cover (2) via an elastic body (25). The breather apparatus for an engine according to claim 2 or 3,
A breather device for an engine, characterized in that molybdate is contained in the separation liquid reservoir recess (23). The breather apparatus for an engine according to any one of claims 2 to 4,
The cylinder head (1) is provided with a cooling water jacket (26), and the separation liquid reservoir recess (23) is composed of a metal bowl-shaped plug (27). A breather device for an engine, characterized in that the opening (26a) is closed. The breather apparatus for an engine according to claim 5,
The separation liquid reservoir recess (23) includes a heat conductor (23a), and the heat conductor (23a) is led out from the inner bottom surface of the separation liquid reservoir recess (23) to the lower end of the separation liquid drain pipe (22). A breather device for an engine. The breather device for an engine according to claim 6,
The engine breather device is characterized in that the cylinder head (1) includes an exhaust port wall (27), and the heat input portion (23b) of the heat conductor (23a) is led out to the exhaust port wall (27). . The breather device for an engine according to any one of claims 1 to 7,
A breather device for an engine, characterized in that the breather box (3) includes a heater (28).

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