JP2014227834A - Auxiliary machine mounting structure for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary machine mounting structure for an internal combustion engine capable of miniaturizing the internal combustion engine, and capable of preventing noise generated by an auxiliary machine from being transmitted to a valve chamber to be amplified.SOLUTION: An auxiliary machine mounting structure includes a cylinder head unit 11 having a valve chamber 10 in an inside thereof, a camshaft (18) disposed in the valve chamber 10, an auxiliary machine (7) having a driven shaft 30 connected to one end of the camshaft (18) in the inside of the valve chamber 10 and driven by the camshaft (18), and an auxiliary machine mounting member 23 interposed between the auxiliary machine (7) and the cylinder head unit 11 in order to mount the auxiliary machine (7) on the cylinder head unit 11. The auxiliary machine mounting member 23 includes a cylindrical body part 41, and a partition wall 47 provided on the cylinder head unit 11 side in the body part 41 and having a through hole 46 through which the driven shaft 30 is inserted, and a chamber 48 separated from the valve chamber 10 by the partition wall 47 is formed in the inside of the auxiliary machine mounting member 23.

Description

  The present invention relates to an auxiliary machine mounting structure for an internal combustion engine for mounting an auxiliary machine having a driven shaft driven by a cam shaft to a cylinder head unit forming a valve operating chamber.

  In an internal combustion engine such as an automobile, the output is not only used for traveling, but also used to drive various auxiliary machines. As described above, the auxiliary machine driven by the internal combustion engine includes an auxiliary machine provided on the end face of the cylinder block and driven by the crankshaft, an auxiliary machine provided on the end face of the cylinder head and driven by the camshaft. is there.

  As an attachment structure of an auxiliary machine driven by a camshaft, in an internal combustion engine in which a plurality of cylinders are arranged in a row, the end of the camshaft protrudes from one end face of the cylinder head, and the camshaft protrudes from one end face of the cylinder head An auxiliary machine having a driven shaft that is driven by the motor is attached, and the protruding end of the cam shaft and the end of the driven shaft of the auxiliary machine are engaged to form a rotation engaging portion, and the cam is attached to the protruding end of the cam shaft. One having a sensor rotor for detecting the rotation angle of the shaft is known (see Patent Document 1).

JP 2011-47373 A

  By the way, in the auxiliary machine attachment structure of patent document 1, the cam holder (support wall) which supports a cam journal is provided in the edge part by the side of the cylinder head provided with the auxiliary machine. Therefore, even when the auxiliary machine generates noise, the noise is blocked by the cam holder, and the noise transmitted to the valve operating chamber does not resonate and amplify the cylinder head cover. On the other hand, in this configuration, since the engaging portion between the cam shaft and the driven shaft of the auxiliary machine is located outside the valve operating chamber, downsizing of the internal combustion engine is hindered, and the layout of other members is obstructed. Also become. Here, in order to reduce the size of the internal combustion engine or the like, it may be possible to adopt a structure in which the cam holder is not provided at the end of the cylinder head on the side where the auxiliary machine is provided. There is a risk that the cylinder head cover will resonate and amplify through the valve chamber.

  The present invention has been made in view of such a background, and provides an auxiliary machine mounting structure for an internal combustion engine that can reduce the size of the internal combustion engine and prevent noise generated by the auxiliary machine from being transmitted to the valve operating chamber and amplifying it. The purpose is to do.

  In order to solve such a problem, according to one aspect of the present invention, a plurality of cylinder bores (9a) are fastened to an upper surface of a cylinder block (9), and a valve operating chamber (10) is provided inside. A cylinder head unit (11) to be formed, a cam shaft (18) disposed in the valve operating chamber (10) along the arrangement direction of the cylinder bores (9a), and the inside of the valve operating chamber (10) Auxiliary attachment structure of internal combustion engine (3) having an auxiliary machine (negative pressure pump 7) having a driven shaft (30) connected to one end of cam shaft (18) and driven by cam shaft (18) An auxiliary machine mounting member (23) interposed between the auxiliary machine (7) and the cylinder head unit (11) to mount the auxiliary machine (7) to the cylinder head unit (11). The auxiliary machine mounting portion (23) is provided on the cylinder head unit (11) side of the main body (41), and has a cylindrical main body (41) for receiving the driven shaft (30), and the driven shaft (30). ) Through which a through hole (46) is formed, and a chamber (48) separated from the valve operating chamber (10) by the partition wall (47) is connected to the accessory mounting member ( 23).

  According to this configuration, the internal combustion engine can be reduced in size by connecting the camshaft and the driven shaft of the accessory in the valve operating chamber, and the chamber formed in the main body of the accessory mounting member By separating the valve operating chamber from the partition wall, the vibration of the auxiliary machine is hardly transmitted to the valve operating chamber, and the silence of the internal combustion engine can be maintained.

  Further, according to one aspect of the present invention, the auxiliary valve mounting member (23) is provided with the valve operating valve for discharging the lubricating oil supplied to the auxiliary machine (7) to the valve operating chamber (10). An oil return hole (49) that allows the chamber (10) to communicate with the lower part of the chamber (48) may be formed.

  According to this configuration, since the lubricating oil supplied to the auxiliary machine can be discharged from the oil return hole to the valve operating chamber, the lubricating oil is accumulated in the housing and the chamber of the auxiliary machine and becomes a resistance for driving the auxiliary machine. Can be prevented. Further, since the lubricating oil can be prevented from accumulating in the chamber, the amount of return of the lubricating oil can be secured and sufficient lubrication of the internal combustion engine can be performed with a small amount of lubricating oil.

  Further, according to one aspect of the present invention, one end of the accessory mounting member (23) is connected to the in-head lubricating oil passage (22) formed in the cylinder head unit (11), and the other end is An intermediate lubricating oil passage (45) connected to the auxiliary lubricating oil passage (37) formed in the auxiliary machine (7) is formed, and the oil return hole (49) is more than the intermediate lubricating oil passage (45). It can be set as the structure formed so that it might have a big flow-path cross-sectional area.

  According to this structure, it can prevent more reliably that lubricating oil accumulates in the housing and chamber of an auxiliary machine.

  Further, according to one aspect of the present invention, one end of the accessory mounting member (23) is connected to the in-head lubricating oil passage (22) formed in the cylinder head unit (11), and the other end is An intermediate lubricating oil passage (45) connected to the auxiliary lubricating oil passage (37) formed in the auxiliary machine (7) is formed, and the oil return hole (49) is more than the intermediate lubricating oil passage (45). It can be set as the structure formed so that it might have a small channel cross-sectional area.

  According to this configuration, the amount of lubricating oil returned from the chamber to the valve operating chamber can be made smaller than the amount of lubricating oil supplied to the auxiliary machine from the intermediate lubricating oil passage, so that the lubricating oil discharged from the auxiliary machine during operation of the internal combustion engine can be reduced. The oil return hole is closed by the oil, and the vibration in the chamber is hardly transmitted to the valve operating chamber. As a result, effects such as improvement in the quietness of the internal combustion engine, extending the life of the auxiliary machine, and reducing the amount of lubricating oil can be expected.

  According to another aspect of the present invention, the cylinder head unit (11) includes a cylinder head (12) fastened to an upper surface of the cylinder block (9), and the cam on the upper surface of the cylinder head (12). A head cover body (13) fastened to a part of the other end side of the shaft (18), and a cam fastened to a part of the one end side of the cam shaft (18) on the upper surface of the cylinder head (12) A sensor holder (14) having a cam angle sensor mounting portion (14a) for detecting the rotation angle of the shaft (18), and the auxiliary device mounting member (23) is connected to the cylinder head (12) and the sensor. It can be set as the structure arrange | positioned ranging over a holder (14).

  According to this configuration, a relatively heavy auxiliary machine can be attached to the cylinder head unit in a stable state. Further, the seal opening between the sensor holder and the cylinder head can be suppressed. Furthermore, since the cylinder head cover is divided into the sensor holder and the head cover body, it is difficult to transmit the vibration of the auxiliary machine to the head cover body, and the amplification of the vibration can be suppressed.

  According to another aspect of the present invention, the auxiliary machine may be a negative pressure pump (7) that discharges the sucked air into the valve operating chamber (10).

  When the pressure wave of the air discharged from the negative pressure pump is transmitted to the valve chamber, the thin part of the cylinder head unit (cylinder head cover) resonates and noise is likely to be amplified. However, according to the configuration, it is discharged from the negative pressure pump. The air to be discharged is first discharged into the chamber and then into the valve operating chamber, so that noise amplification can be prevented.

  As described above, according to the present invention, an auxiliary machine for an internal combustion engine that can prevent noise generated by the auxiliary machine from being transmitted to the valve chamber and amplifying without providing a cam holder at the end of the cylinder head on the side where the auxiliary machine is provided. An attachment structure can be provided.

Configuration diagram of a negative pressure circuit system to which an auxiliary machine mounting structure according to the present invention is applied The exploded perspective view of the auxiliary machine attachment structure concerning the present invention Longitudinal sectional view of the auxiliary equipment mounting structure shown in FIG. The exploded perspective view which looked at the pump and attachment member shown in FIG. 2 from a different direction The perspective view shown in the state which integrated the pump and the attachment member shown in FIG. Longitudinal sectional view of auxiliary equipment mounting structure according to a modification of the present invention

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an accessory mounting structure according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a negative pressure circuit system 1 is mounted on an automobile. A negative pressure circuit system 1 is connected to a brake pedal 2 and is connected to an intake manifold 4 fastened to an internal combustion engine 3 via a negative pressure pipe 5 and similarly to a brake booster 6 (master power). A negative pressure pump 7 is connected to the brake booster 6 via the pipe 5 and driven by the internal combustion engine 3. Each negative pressure pipe 5 is provided with a check valve 8 so that air does not flow backward to the brake booster 6 side. In this negative pressure circuit system 1, the brake booster 6 is evacuated by the intake manifold 4 and the negative pressure pump 7, thereby generating a negative pressure therein and amplifying the depression force of the brake pedal 2.

  In the internal combustion engine 3, a cylinder head unit 11 that forms a valve operating chamber 10 is fastened to an upper surface of an open deck type cylinder block 9 that forms a plurality (four in this case) of cylinder bores 9a in a row. This is an in-line multi-cylinder engine in which the upper end of the cylinder bore 9a is closed. The internal combustion engine 3 is here configured as a gasoline engine.

  As shown in FIG. 2, the cylinder head unit 11 includes a cylinder head 12 fastened to the upper surface of the cylinder block 9 (FIG. 1), and one side in the cylinder row direction on the upper surface of the cylinder head 12 (hereinafter, this direction is referred to as the front side). Head cover body 13 (shown in phantom lines in FIG. 2) fastened to a part of the cylinder head 12 and the other side of the cylinder head 12 in the cylinder row direction (hereinafter, this direction is referred to as the rear). And a sensor holder 14 having a cam angle sensor mounting portion 14a (not shown). Here, the cylinder head 12 and the sensor holder 14 are formed as castings made of an aluminum alloy. In other embodiments, the cylinder head 12 and the sensor holder 14 may be formed using a metal other than an aluminum alloy. On the other hand, the head cover main body 13 is here formed as an injection-molded product made of resin. In another embodiment, the head cover body 13 may be formed as a press-formed product using a cast product such as an aluminum alloy or a steel plate.

  The cylinder head 12 has a rectangular shape that is long in the cylinder row direction in plan view, and has a rectangular base portion 15 that defines the upper surface of a combustion chamber (not shown), and an annular side wall that rises along the outer edge of the base portion 15. The lower part of the valve operating chamber 10 is formed in the part surrounded by the side wall 16. A plurality of cam holders 17 arranged at predetermined intervals in the longitudinal direction are formed in two rows on the upper surface of the inner side of the side wall 16 in the base portion 15 of the cylinder head 12 so as to protrude upward, The intake camshaft 18 and the exhaust camshaft 19 are rotatably supported by these cam holders 17 so as to extend along the cylinder row direction.

  The head cover main body 13 and the sensor holder 14 are fastened to the upper surface of the side wall 16 of the cylinder head 12 by a plurality of bolts B1. When the head cover body 13 and the sensor holder 14 are fastened to the side wall 16, the valve operating chamber 10 formed by the cylinder head 12 is expanded upward. As shown, the inner portion of the fastening surface has a cup shape protruding upward. Since the head cover body 13 and the sensor holder 14 are configured in this manner, the valve operating chamber 10 is formed inside the cylinder head unit 11 in cooperation with the cylinder head 12.

  As shown in FIG. 3, the intake camshaft 18 and the exhaust camshaft 19 are formed in a hollow bar shape so as to form a lubricating oil passage therein, and are held at a position higher than the upper surface of the cylinder head 12 by the cam holder 17. ing. The rear end of the intake camshaft 18 is located inside the sensor holder 14, that is, in the valve operating chamber 10, and an engagement groove 18a extending in the radial direction through the center is formed on the rear end surface. Yes. In other words, the rear end of the intake camshaft 18 is provided with a pair of arcuate walls that protrude rearward and face each other. A plug 20 is press-fitted into the hollow portion of the intake camshaft 18 at a position in front of the engagement groove 18a. The plug 20 is provided with a small hole (not shown) so that the lubricating oil is jetted backward. In addition, a disc-shaped pulsar plate 18b that forms a portion to be detected by the cam angle sensor described above is integrally provided on the outer periphery in front of the engagement groove 18a of the intake camshaft 18 by press-fitting.

  A flat accessory mounting surface 21 is formed on the side surface on the rear end side of the cylinder head unit 11. The accessory mounting surface 21 is formed so as to straddle the upper part of the side wall 16 of the cylinder head 12 and the sensor holder 14. The auxiliary machine mounting surface 21 is formed relatively large by the upper edge of the side wall 16 of the cylinder head 12 and the notch formed in the sensor holder 14, and a first through hole 21 a that communicates the valve operating chamber 10 and the outside. A second through hole 21b formed smaller than the first through hole 21a is opened at a position below the first through hole 21a in the side wall 16 of the cylinder head 12. Further, in the side wall 16 of the cylinder head 12, the in-head lubricating oil passage 22 for supplying lubricating oil to the negative pressure pump 7 is the same as the auxiliary machine mounting surface 21 at a position that is obliquely separated from the auxiliary machine mounting surface 21. Open on a plane. The negative pressure pump 7 described above is attached to the accessory mounting surface 21 of the cylinder head unit 11 via the accessory mounting member 23.

  As shown in FIGS. 3 and 4, the negative pressure pump 7 is a known vane type vacuum pump, and has a pump case 24 having a bottomed cylindrical shape that opens rearward, and an open end side (rear side) of the pump case 24. And a pump cover 28 that defines the pump chamber 27 in cooperation with the pump case 24. The pump case 24 has a cylindrical portion 24a in which the suction port 25 is formed and a bottom wall portion 24b in which the discharge port 26 is formed. A rotor 29 that is supported by the bottom wall portion 24b of the pump case 24 and has vanes (not shown) on the outer periphery thereof is rotatably provided at a position in the pump chamber 27 that is eccentric with respect to the pump chamber 27. At the front end of the rotor 29, a reduced diameter portion 29a having a non-circular cross section is formed to protrude, and a driven shaft 30 having a hole with a shape similar to the cross sectional shape of the reduced diameter portion 29a is slightly formed on the front surface. It is externally fitted to the reduced diameter portion 29a with the movement allowance. As a result, the driven shaft 30 is held at a position protruding outward from the pump case 24 and rotates integrally with the rotor 29. A center hole is formed on the axis of the driven shaft 30 so that the driven shaft 30 does not come off the rotor 29, and a headed plug 31 (press-fit male screw) inserted into the center hole is provided on the rotor 29. It is press-fitted into the reduced diameter portion 29a while being threaded. The driven shaft 30 has a circular cross-sectional shape at the rear portion and a single-character cross-sectional shape at the front portion to constitute an engaging convex portion 30a.

  As shown in FIG. 4, a reed valve 32 made of an elastic plate piece is provided outside the discharge port 26 of the pump case 24 so that air does not flow backward from the discharge port 26 to the pump chamber 27. . Further, a stopper 33 made of a highly rigid plate piece is provided on the bottom wall portion 24 b of the pump case 24 at a position separated from the reed valve 32 so as to cover the reed valve 32. Thereby, the movement amount of the reed valve 32 in the opening direction is limited by the stopper 33.

  In a state where the negative pressure pump 7 is fastened to the cylinder head unit 11 via the accessory mounting member 23, the engagement convex portion 30a at the front end of the driven shaft 30 is provided inside the valve operating chamber 10, as shown in FIG. Enters and engages with the engagement groove 18 a at the rear end of the intake camshaft 18. As a result, the driven shaft 30 is rotationally driven by the intake camshaft 18. In other embodiments, the driven shaft 30 of the negative pressure pump 7 may be rotationally driven by the exhaust camshaft 19. When the driven shaft 30 is rotationally driven and the rotor 29 rotates integrally with the driven shaft 30, the vane rotates in the pump chamber 27 and the air taken in from the suction port 25 is compressed in the pump chamber 27 and discharged. 26 is discharged. At this time, the compressed air discharged from the discharge port 26 is noise because it is a pressure wave. Note that the lubricating oil ejected from the small hole of the plug 20 is supplied to the engaging portion between the driven shaft 30 and the intake camshaft 18.

  As shown in FIG. 4, on the outer periphery of the front portion of the pump case 24, three mounting bosses 35 each forming a bolt insertion hole 34 are radially projected from different positions in the circumferential direction. Further, the front end of the pump case 24 projects forward from the fastening surface of these mounting bosses 35, and when mounted on the accessory mounting member 23 (FIG. 3), a circular projecting portion 24c that enters the accessory mounting member 23. Is formed. An annular groove 24d is formed on the outer peripheral surface of the circular protrusion 24c, and the pump case 24 is attached to the accessory mounting member 23 by installing an O-ring 36 (FIG. 3) in the annular groove 24d. The liquid-tightness between the two is ensured. Furthermore, the circular protrusion 24c of the pump case 24 is formed with a protrusion 24e that protrudes forward along the outer edge of the circular protrusion 24c. On the outer surface of the projection 24e, an in-pump lubricating oil passage 37 for supplying lubricating oil to a sliding surface (bearing portion) between the pump case 24 and the rotor 29 and a sliding portion of the vane is opened.

  The accessory mounting member 23 has a cylindrical main body 41 that receives the driven shaft 30 and a plurality of (here, 5) integrally formed with the main body 41 so as to project radially from the outer periphery of the main body 41. And a mounting boss 42. A bolt insertion hole 43 or a female screw hole 44 is formed in the mounting boss 42. In this embodiment, female screw holes 44 are formed in two of the three mounting bosses 42 corresponding to the mounting bosses 35 of the pump case 24, and bolt insertion holes 43 are formed in the remaining three mounting bosses 42. . That is, two of the three mounting bosses 35 of the pump case 24 are fastened to the accessory mounting member 23 by two bolts B2, and the remaining one mounting boss 35 of the pump case 24 is supplemented by one bolt B3. Together with the machine mounting member 23, the cylinder head unit 11 is fastened together, and the remaining two mounting bosses 42 of the auxiliary machine mounting member 23 are fastened to the cylinder head unit 11 by two bolts B4 (FIG. 2). When the negative pressure pump 7 is fastened to the accessory mounting member 23 by the two bolts B1, an assembled state is obtained as shown in FIG.

  As shown in FIGS. 4 and 5, one front surface of the lower two mounting bosses 42 connected to the cylinder head unit 11 by the bolt B <b> 3 is connected to the in-pump lubricating oil passage 37. The upstream end of the intermediate lubricating oil passage 45 is open. The intermediate lubricating oil passage 45 extends rearward from the upstream end, bends toward the center of the main body 41, and the downstream end opens on the inner peripheral surface of the main body 41. When the negative pressure pump 7 is fastened to the accessory mounting member 23 (FIG. 5), the downstream end of the intermediate lubricating oil passage 45 is connected to the in-pump lubricating oil passage 37 (FIG. 4). As a result, the lubricating oil supplied from the in-head lubricating oil passage 22 is supplied to the in-pump lubricating oil passage 37 through the intermediate lubricating oil passage 45.

  A circular partition wall 47 having a through hole 46 through which the driven shaft 30 is inserted is formed integrally with the main body portion 41 at the front portion of the main body portion 41 of the accessory mounting member 23. As a result, in a state where the negative pressure pump 7 is fastened to the accessory mounting member 23 (FIG. 5), the driven shaft 30 protrudes forward from the partition wall 47, and as shown in FIG. 3, the negative pressure pump In a state where 7 is fastened to the cylinder head unit 11 via the accessory mounting member 23, the engagement convex portion 30 a of the driven shaft 30 enters and engages with the engagement groove 18 a of the intake camshaft 18. Further, due to the presence of the partition wall 47, a chamber 48 separated from the valve operating chamber 10 is formed inside the main body portion 41 of the accessory mounting member 23. As a result, the compressed air discharged from the negative pressure pump 7 is first discharged into the chamber 48 and then into the valve chamber 10 from the gap between the partition wall 47 and the driven shaft 30 and the oil return hole 49 described later. Discharged.

  Returning to FIGS. 4 and 5, an oil return hole 49 is formed below the partition wall 47 so as to pass through the accessory mounting member 23 in the front-rear direction and communicate the chamber 48 with the front space of the accessory mounting member 23. Yes. The oil return hole 49 is formed so as to have a cross-sectional area larger than that of the intermediate lubricating oil passage 45, and here is formed so as to have a cross-sectional area equivalent to the air outlet 26 of the negative pressure pump 7. . As shown in FIGS. 2 and 3, the second through hole 21b of the cylinder head 12 described above is provided at a position corresponding to the oil return hole 49, and the oil discharged from the oil return hole 49 is second. It flows into the valve operating chamber 10 through the through hole 21b, and returns to the oil pan through a predetermined return passage in the same manner as the other lubricating oil in the valve operating chamber 10.

  As shown in FIGS. 4 and 5, a first annular groove 51 is formed on the front surface of the accessory mounting member 23 so as to surround the partition wall 47 and the oil return hole 49, and the upstream opening of the intermediate lubricating oil passage 45. A second annular groove 52 is formed so as to surround. A linear groove 53 is also formed so as to connect the first annular groove 51 and the second annular groove 52. In the first annular groove 51, the second annular groove 52, and the linear groove 53, an integral seal member 54 (FIG. 3) that conforms to this shape is disposed, and the auxiliary machine mounting member 23 with respect to the cylinder head unit 11 is disposed. Liquid tightness and liquid tightness between the in-pump lubricating oil passage 37 and the intermediate lubricating oil passage 45 are ensured.

  Thus, the negative pressure pump 7 is fastened to the cylinder head unit 11 via the accessory mounting member 23 and, as shown in FIG. 3, a chamber separated from the valve operating chamber 10 by the partition wall 47 of the accessory mounting member 23. Since 48 is formed in the accessory mounting member 23, the pressure wave of the air discharged from the negative pressure pump 7 is not easily transmitted to the valve operating chamber 10. Therefore, the head cover body 13 having relatively low rigidity does not resonate and amplify noise. Further, the intake camshaft 18 and the driven shaft 30 of the negative pressure pump 7 are connected inside the valve operating chamber 10, whereby the internal combustion engine 3 can be downsized.

  Further, since the negative pressure pump 7 is fastened to the cylinder head unit 11 via the accessory mounting member 23, a fastening portion can be provided in the cylinder head unit 11 regardless of the position of the mounting boss 35 of the negative pressure pump 7. The versatility of the negative pressure pump 7 can be increased, or the layout flexibility of the cylinder head unit 11 can be increased.

  In this embodiment, an intermediate lubricating oil passage 45 (FIG. 4) is connected to the in-head lubricating oil passage 22 (FIG. 2) and the downstream end is connected to the in-pump lubricating oil passage 37 (FIG. 4). Formed on the mounting member 23, the lubricating oil is supplied to the negative pressure pump 7. An oil return hole 49 opening in the lower portion of the chamber 48 is formed in the accessory mounting member 23, and lubricating oil used for lubrication in the negative pressure pump 7 is discharged to the valve operating chamber 10 through the oil return hole 49. Therefore, it is possible to prevent the lubricating oil from accumulating in the pump chamber 27 and the chamber 48 of the negative pressure pump 7 and becoming a driving resistance of the negative pressure pump 7. Further, since the cross-sectional area of the oil return hole 49 is larger than the cross-sectional area of the intermediate lubricating oil passage 45, it is possible to reliably prevent the lubricating oil from accumulating in the pump chamber 27 and the chamber 48. As a result, the return amount of the lubricating oil to the oil pan is ensured, so that the internal combustion engine 3 can be sufficiently lubricated with a small amount of lubricating oil.

  Further, in this embodiment, as shown in FIG. 2, the head cover body 13 and the sensor holder 14 are fastened to the upper surface of the cylinder head 12, and the accessory mounting member 23 is disposed across the cylinder head 12 and the sensor holder 14. Thus, the relatively heavy negative pressure pump 7 is attached to the cylinder head unit 11 in a stable state. Further, the seal opening between the sensor holder 14 and the cylinder head 12 is also suppressed. Furthermore, since the cylinder head cover is divided into the sensor holder 14 and the head cover main body 13, the vibration of the negative pressure pump 7 is hardly transmitted to the head cover main body 13, and the amplification of the vibration is suppressed.

  On the other hand, when priority is given to ensuring the quietness of the internal combustion engine with respect to prevention of the retention of the lubricating oil in the pump chamber 27 and the chamber 48, as shown in FIG. The oil return hole 49 may be formed so that the cross-sectional area of the flow path is smaller than that of the intermediate lubricating oil path 45. With this configuration, the amount of lubricating oil returned from the chamber 48 to the valve operating chamber 10 is smaller than the amount of lubricating oil supplied from the intermediate lubricating oil passage 45 to the negative pressure pump 7, and the operation of the internal combustion engine 3. Sometimes, the oil return hole 49 is closed by the lubricating oil discharged from the negative pressure pump 7. Therefore, it is difficult for vibration in the chamber 48 to be transmitted by the valve train 10.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, the vane negative pressure pump 7 is attached to the cylinder head unit 11 as an example of an auxiliary machine, but other types of vacuum pumps, liquid feed pumps such as fuel pumps, and other auxiliary machines It can also be applied to. In the above embodiment, the internal combustion engine 3 has been described for automobiles, but the present invention can be widely applied to railway vehicles, general-purpose engines, and the like. In the embodiment described above, the partition wall 47 is described as being integrally formed with the main body portion 41, but the partition wall 47 formed separately from the main body portion 41 may be integrally attached to the main body portion 41. Further, in the above embodiment, the auxiliary machine mounting member 23 is described as being configured separately from the negative pressure pump 7, but the chamber 48 is formed by the cylindrical main body 41 and the partition wall 47, and the same effect is obtained. If played, the entire auxiliary equipment mounting member 23 or the main body 41 may be integrated with the negative pressure pump 7. In addition, the specific configuration, arrangement, material, quantity, and the like of each member and part can be changed as appropriate without departing from the spirit of the present invention. On the other hand, all the components of the accessory mounting structure shown in the above embodiment are not necessarily essential, and can be appropriately selected.

7 Negative pressure pump (auxiliary machine)
DESCRIPTION OF SYMBOLS 9 Cylinder block 9a Cylinder bore 10 Valve chamber 11 Cylinder head unit 12 Cylinder head 13 Head cover main body 14 Sensor holder 14a Cam angle sensor mounting part 18 Intake camshaft 22 In-head lubricating oil path 23 Auxiliary equipment mounting member 30 Driven shaft 37 Pump Inner lubricating oil passage (auxiliary inner lubricating oil passage)
41 Body 45 Intermediate Lubricating Oil Path 46 Through-hole 47 Bulkhead 48 Chamber 49 Oil Return Hole

Claims (6)

A cylinder head unit that is fastened to an upper surface of a cylinder block that forms a plurality of cylinder bores in a row, and that forms a valve operating chamber therein;
A camshaft disposed in the valve operating chamber along the arrangement direction of the cylinder bores;
An auxiliary machine mounting structure for an internal combustion engine having an auxiliary machine connected to one end of the camshaft and driven by the camshaft inside the valve operating chamber;
An auxiliary machine attachment member interposed between the auxiliary machine and the cylinder head unit to attach the auxiliary machine to the cylinder head unit;
The accessory mounting member includes a cylindrical main body portion that receives the driven shaft, and a partition wall that is provided on the cylinder head unit side of the main body portion and has a through hole through which the driven shaft is inserted. Have
An auxiliary machine mounting structure for an internal combustion engine, wherein a chamber separated from the valve operating chamber by the partition wall is formed in the auxiliary machine mounting member.   The accessory mounting member is formed with an oil return hole for communicating the valve operating chamber and a lower portion of the chamber so as to discharge the lubricating oil supplied to the accessory to the valve operating chamber. An auxiliary machine mounting structure for an internal combustion engine according to claim 1. The auxiliary machine mounting member has an intermediate lubricating oil path that has one end connected to the in-head lubricating oil path formed in the cylinder head unit and the other end connected to the auxiliary lubricating oil path formed in the auxiliary machine. Formed,
The auxiliary machine mounting structure for an internal combustion engine according to claim 2, wherein the oil return hole is formed so as to have a larger flow path cross-sectional area than the intermediate lubricating oil path. The auxiliary machine mounting member has an intermediate lubricating oil path that has one end connected to the in-head lubricating oil path formed in the cylinder head unit and the other end connected to the auxiliary lubricating oil path formed in the auxiliary machine. Formed,
The auxiliary machine mounting structure for an internal combustion engine according to claim 2, wherein the oil return hole is formed to have a smaller flow path cross-sectional area than the intermediate lubricating oil path. The cylinder head unit includes a cylinder head fastened to the upper surface of the cylinder block, a head cover body fastened to a part of the upper surface of the cylinder head on the other end side of the cam shaft, and the one end side of the cam shaft. And a sensor holder that is fastened to a part of the upper surface of the cylinder head and includes a cam angle sensor mounting portion that detects a rotation angle of the cam shaft,
The auxiliary machine attachment structure for an internal combustion engine according to any one of claims 1 to 4, wherein the auxiliary machine attachment member is disposed across the cylinder head and the sensor holder.   The auxiliary machine mounting structure for an internal combustion engine according to any one of claims 1 to 5, wherein the auxiliary machine is a negative pressure pump that discharges the sucked air into the valve operating chamber.

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