JP2016160796A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of shortening length in a cam axial direction of a cylinder head, and downsizing the internal combustion engine.SOLUTION: In an engine 1, a locker arm 19 and a plunger 52 of a fuel pump 41 are disposed so as to sandwich an intake cam shaft 13. A bolt 76C is installed separately from bearing supporting portions 33A and 72a in an axial direction of the intake cam shaft 13. In an upper surface view of a cylinder head 11, so as to superimpose a second side wall portion 72 of a fuel pump attaching bracket 42 on the bearing supporting portions 33A and 72a, the fuel pump attaching bracket 42 is attached to the cylinder head 11.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine having a fuel pump mounting bracket for mounting a fuel pump to a cylinder head.

  A cylinder head of an internal combustion engine mounted on a vehicle such as an automobile is provided with a cam shaft having a cam lobe that presses a valve lifter for driving an intake / exhaust valve, and the cam shaft is rotatably supported by the cylinder head. Has been.

One camshaft is provided with a pump drive cam that discharges high-pressure fuel from the fuel pump by moving the plunger of the fuel pump as the camshaft rotates.
Since this cam shaft receives loads from both the valve lifter and the fuel pump, it is necessary to attach the cam shaft to the cylinder head with high rigidity.

  Conventionally, a camshaft having a pump drive cam is attached to a cylinder head. The camshaft end is extended to the outside of the side wall of the cylinder head, and a pump drive cam for driving the fuel pump is provided at the end of the camshaft. An internal combustion engine in which a cam shaft is attached to a side wall of a cylinder head by a cam housing is known (for example, see Patent Document 1).

  The internal combustion engine is attached to the cylinder head by a pair of bolts, and the bolts are attached at symmetrical positions with the cam shaft interposed therebetween. Thereby, the cam housing can be firmly fastened to the cylinder head by the bolt, and the rigidity of the cam shaft can be increased.

Japanese Patent Laying-Open No. 2001-107773 (FIG. 2)

  In the conventional internal combustion engine, since it is necessary to firmly fasten the cam housing to the cylinder head with bolts, the bolts must be installed at symmetrical positions on the side wall across the cam shaft. The degree of freedom of the installation position becomes low.

For this reason, it is necessary to install the bracket for attaching the fuel pump to the cylinder head at a position separated from the side wall to the outside. As a result, the fuel pump is installed at a position separated from the side wall to the outside.
As a result, the axial length of the cam shaft of the cylinder head becomes long, and as a result, the internal combustion engine may become large.

  The present invention has been made paying attention to the above problems, and provides an internal combustion engine in which the length of the cylinder head in the cam shaft direction can be shortened and the internal combustion engine can be miniaturized. It is for the purpose.

  The present invention is attached to a cylinder head, a valve lifter that opens and closes a valve, a fuel pump mounting bracket that is fixed to the cylinder head by a plurality of fastening members so as to cover the cylinder head, and is fixed to the fuel pump mounting bracket. A fuel pump that pressurizes fuel by moving the plunger, a bearing portion that is rotatably attached to a bearing support portion formed by a cylinder head and a fuel pump mounting bracket, a cam lobe that presses the valve lifter, and a plunger of the fuel pump And a camshaft having a pump drive cam that presses the valve, the valve lifter and the plunger are installed so as to sandwich the camshaft, the end of the camshaft extends outside from the side wall, and the auxiliary shaft is driven by the end of the camshaft An internal combustion engine configured as described above, wherein At least one of the fuel pump mounting bracket is installed in the cylinder head so as to be spaced apart from the bearing support portion in the axial direction of the camshaft, and a part of the fuel pump mounting bracket overlaps the bearing support portion in a top view of the cylinder head. It is composed of what can be attached to.

As described above, according to the present invention, since the plunger and the valve lifter are installed so as to sandwich the cam shaft, the load applied from the plunger to the cam shaft and the load applied from the valve lifter to the cam shaft when viewed from the axial direction of the cam shaft. By reversing the direction, the load applied from the plunger to the cam shaft and the load applied from the valve lifter to the cam shaft can be offset.
This eliminates the need to firmly fasten the fuel pump mounting bracket to the cylinder head across the camshaft bearing.

  For this reason, at least one of the plurality of fastening members is installed apart from the bearing support portion in the axial direction of the cam shaft, and a part of the fuel pump mounting bracket is connected to the bearing support portion in a top view of the cylinder head. The fuel pump mounting bracket can be attached to the cylinder head so as to overlap.

In this way, the fuel pump can be installed above the side wall of the cylinder head, that is, the fuel pump can be installed close to the side wall. In addition, by installing the fuel pump above the side wall of the cylinder head, the pump driving cam can be installed close to the side wall, and the length of the pump driving cam and the bearing portion on the cam shaft can be shortened.
As a result, the axial length of the cam shaft of the cylinder head can be shortened, and the internal combustion engine can be downsized.

FIG. 1 is a diagram showing an embodiment of an internal combustion engine according to an embodiment of the present invention, and is a top view of the internal combustion engine. FIG. 2 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a top view of the cylinder head with the cylinder head cover removed. FIG. 3 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a perspective view of the cylinder head with the cylinder head cover removed. FIG. 4 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a front view of the cylinder head with the cylinder head cover removed. FIG. 5 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a top view of the cylinder head in a state where the cylinder head cover and the fuel pump mounting bracket are removed. FIG. 6 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a side view of the internal combustion engine. 7 is a diagram showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a cross-sectional view taken along the line VII-VII in FIG. FIG. 8 is a diagram showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a perspective view of the main part of the cylinder head with the cylinder head cover removed. FIG. 9 is a diagram showing an embodiment of an internal combustion engine according to an embodiment of the present invention, in which the load is input from the fuel pump to the intake camshaft and the load is input from the intake valve to the intake camshaft. FIG. FIG. 10 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a side view of the cylinder head with the cylinder head cover removed. FIG. 11 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a side view of the cylinder head with the cylinder head cover and the fuel pump mounting bracket removed. FIG. 12 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a perspective view of the fuel pump mounting bracket as viewed from the left side of the vehicle. FIG. 13 is a view showing an embodiment of the internal combustion engine according to the embodiment of the present invention, and is a perspective view of the fuel pump mounting bracket as viewed from the front side of the vehicle.

Embodiments of an internal combustion engine according to the present invention will be described below with reference to the drawings.
1 to 13 show an internal combustion engine according to an embodiment of the present invention.
First, the configuration will be described.
In FIG. 1, an engine 1 constituting an internal combustion engine of the present invention is a horizontal 4 that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while a piston (not shown) reciprocates two cylinders. It consists of a cycle engine.

  The engine 1 is mounted on a vehicle, and the engine 1 includes a cylinder head 11 and a cylinder head cover 12. 1 to 13, front and rear, left and right, and up and down directions represent directions viewed from the driver's seat of the vehicle on which the engine 1 is mounted.

  The cylinder head 11 is attached to the upper part of a cylinder block (not shown). The cylinder block has a cylinder (not shown) that accommodates a piston (not shown) so as to be movable up and down, and the vertical movement of the piston is converted into a rotational movement of a crankshaft (not shown) provided in the cylinder block.

  1 and 2, the cylinder head 11 includes a rear side wall portion 31 and a front side wall portion 32 that extend in parallel to the vehicle width direction, and a vehicle side direction of the rear side wall portion 31 and the front side wall portion 32 that extends in the front-rear direction of the vehicle. A left side wall 33 that continues to one end (left end), and a right side wall 34 that extends in the front-rear direction of the vehicle and continues to the other end (right end) in the vehicle width direction of the rear side wall 31 and the front side wall 32 And a bottom wall portion 35 (see FIG. 3) continuous to the lower portion of the front side wall portion 32, the left side wall portion 33, and the right side wall portion 34, and is configured by a rectangular parallelepiped case.

  In FIG. 2, a boss portion 16 that accommodates a spark plug 15 is formed at the center of the cylinder head 11, and the spark plug 15 includes a bottom surface of a bottom wall portion 35 of the cylinder head 11 and an upper portion of a cylinder of a cylinder block. It protrudes into a combustion chamber (not shown) formed by. The engine 1 according to the embodiment is a four-cylinder direct injection gasoline engine having four spark plugs 15.

In FIG. 1, the cylinder head 11 is provided with a plurality of ignition coils 2 to be paired with the ignition plug 15, and the ignition coil 2 ignites the ignition plug 15.
2 and 3, the cylinder head 11 is provided with an intake camshaft 13 and an exhaust camshaft 14 extending in parallel with the intake camshaft 13. 2 and 8, the intake camshaft 13 and the exhaust camshaft 14 are rotatably supported by a lower cam housing 18 and an upper cam housing 17 that serve as bearings installed at the upper part of the cylinder head 11.

  A cam sprocket (not shown) is provided at the right ends of the intake camshaft 13 and the exhaust camshaft 14, and a timing chain (not shown) is wound around the cam sprocket. The timing chain is wound around a cranks plot (not shown) of the crankshaft, and the timing chain transmits the rotation of the crankshaft to the intake camshaft 13 and the exhaust camshaft 14.

  The intake cam shaft 13 is provided with a plurality of intake cams 13 </ b> A. As shown in FIG. 9, the intake cam 13 </ b> A is in contact with the rocker arm 19. The rocker arm 19 is in contact with the pivot 20 </ b> A of the hydraulic lash adjuster 20.

  At the center of the rocker arm 19, a pressed roller 19A is supported by a pin 19B. The pressed roller 19A protrudes from the upper surface of the rocker arm 19, and the pressed roller 19A contacts the intake cam 13A.

  The lower surface of the arm tip 19D on the other end side of the rocker arm 19 is in contact with the upper end of the intake valve 21. The intake valve 21 is provided so as to be able to advance and retract in the axial direction with respect to the cylinder head 11. The intake valve 21 is pulled up by the valve spring 22, that is, an intake port 46 opened and closed by the intake valve 21 (see FIG. 1). ) And the combustion chamber.

  When the rocker arm 19 pushes down the intake valve 21 against the urging force of the valve spring 22 by the rotation of the intake cam 13A, the intake port 46 and the combustion chamber communicate with each other. Thus, the intake valve 21 is moved forward and backward by the rotation of the intake cam 13A, whereby the intake port 46 and the combustion chamber are communicated and blocked. Here, the rocker arm 19 and the valve spring 22 of the present embodiment constitute the valve lifter of the present invention.

  The exhaust camshaft 14 is provided with a plurality of exhaust cams 14A, and the exhaust cams 14A are in contact with the upper end of an exhaust valve (not shown) via a rocker arm (not shown). The exhaust cam 14A is also in contact with the exhaust valve via a rocker arm (not shown) having the same configuration as that of the rocker arm 19, and is driven by the same structure as that of the intake side so that the exhaust port communicates with the combustion chamber. Cut off.

  1 to 4 and 6 to 10, a fuel pump 41 and a fuel pump mounting bracket 42 are attached to the cylinder head 11. The fuel pump 41 is provided with a fuel supply pipe 44, and low pressure fuel is supplied to the fuel pump 41 from the fuel supply pipe 44.

The fuel pump 41 is provided with a fuel supply pipe 43, and the fuel adjusted by the fuel pump 41 is introduced into the fuel supply pipe 43.
In FIG. 1, a delivery pipe 45 is provided in the cylinder head 11, and the delivery pipe 45 supplies the fuel introduced from the fuel supply pipe 43 to a fuel injection valve (not shown).

  The fuel injection valve is installed for each combustion chamber of the cylinder head 11, and the delivery pipe 45 distributes and supplies the high-pressure fuel introduced from the fuel supply pipe 43 to the fuel injection valve. The fuel injection valve directly injects high-pressure fuel supplied from the delivery pipe 45 into the combustion chamber.

  In FIG. 1, a plurality of intake ports 46 are formed in the rear side wall portion 31, and each intake port 46 communicates with a cylinder. An intake manifold (not shown) is attached to the rear side wall 31, and the intake manifold distributes and introduces intake air purified by an air cleaner (not shown) to each intake port 46.

  3 and 4, an exhaust collecting passage 47 is formed in the front side wall portion 32, and the exhaust collecting passage 47 collects exhaust ports communicating with the respective combustion chambers. The exhaust gas collected in the exhaust collecting passage 47 through the exhaust port from the cylinder is purified by a catalyst device (not shown) communicating with the exhaust collecting passage 47 and then exhausted to an exhaust pipe (not shown). Further, a turbocharger turbine housing (not shown) may be provided between the catalyst device and the exhaust collecting passage 47.

Here, the cylinder head 11 and the fuel pump mounting bracket 42 of the present embodiment are made of a metal material, and the cylinder head cover 12 is made of a resin material.
4, 7, and 8, the intake camshaft 13 is provided with a pump drive cam 13B, and the fuel pump 41 is driven by the pump drive cam 13B.

  In FIG. 7, the fuel pump 41 includes a pump body 51, a plunger 52, an electromagnetic valve 53, a spring 54, and a connector 55 that electrically connects the electromagnetic valve 53 and a controller (not shown).

  The pump body 51 includes a suction port 51a for sucking fuel, a discharge port 51b for discharging fuel, a pressure chamber 51c communicating with the suction port 51a and the discharge port 51b, and an opening / closing valve for opening and closing the suction port 51a with an electromagnetic valve 53. 51d. The pump main body 51 includes a cylinder 51e that movably accommodates the plunger 52, and a flange 51f that attaches the pump main body 51 to the fuel pump mounting bracket 42.

  The intake port 51 a is connected to the fuel supply pipe 44, and the discharge port 51 b is connected to the fuel supply pipe 43. The discharge port 51b is provided with a check valve (not shown). The check valve opens when the fuel pressure in the pressure chamber 51c exceeds a predetermined value, and discharges fuel from the discharge port 51b into the fuel supply pipe 43. To do.

  The plunger 52 has a roller 52a that contacts the pump drive cam 13B and a lifter member 52b that rotatably supports the roller 52a. The lifter member 52b is pressed toward the pump drive cam 13B by a spring 54, and the roller 52a is in contact with the pump drive cam 13B with a predetermined pressing force. Thereby, the plunger 52 reciprocates in the direction orthogonal to the axial direction of the intake camshaft 13 by the rotational movement of the pump drive cam 13B.

  The fuel pump 41 sucks fuel into the pressure chamber 51c where the suction port 51a is opened and the volume is increased when the plunger 52 is lowered by the rotation of the pump drive cam 13B. Further, in the fuel pump 41, when the plunger 52 is raised by the rotation of the pump drive cam 13B, the suction port 51a is closed, and the pressure of the fuel sucked into the pressure chamber 51c is increased.

  The electromagnetic valve 53 has a solenoid controlled by a controller. The solenoid valve 53 opens the on-off valve 51d when sucking fuel from the suction port 51a, and communicates between the pressure chamber 51c and the suction port 51a when increasing the fuel pressure. Shut off.

  In FIG. 9, the intake cam 13 </ b> A and the plunger 52 of the fuel pump 41 are installed so as to sandwich the intake cam shaft 13. As a result, the direction of the load F1 applied from the rocker arm 19 to the intake camshaft 13 by the valve spring 22 is opposite to the direction of the load F2 applied from the plunger 52 to the intake camshaft 13 by the spring 54.

  7 and 8, the left end portion 13a of the intake camshaft 13 extends outside the left side wall portion 33 with respect to the inside of the cylinder head 11 provided with the intake cam 13A, the pump drive cam 13B, and the exhaust cam 14A. ing.

  Here, the intake camshaft 13 of the present embodiment constitutes the camshaft of the present invention, and the intake cam 13A constitutes the cam lobe of the present invention. Further, the left end portion 13a of the intake camshaft 13 constitutes an end portion of the camshaft of the present invention.

  A sensing rotor 61 is provided at the left end 13a of the intake camshaft 13 that extends to the outside from the left side wall 33, and the sensing rotor 61 is formed with a plurality of protrusions 61A having different lengths in the circumferential direction. Yes. A cam angle sensor 62 is provided at a position facing the sensing rotor 61 (see FIGS. 10 and 11), and the cam angle sensor 62 detects the rotation angle of the sensing rotor 61.

Here, the sensing rotor 61 of the present embodiment constitutes a detected rotor of the present invention, and the cam angle sensor 62 constitutes a rotation angle detection sensor.
In FIG. 7, the left end bearing portion 13 b of the intake camshaft 13 is rotatably supported by the left side wall portion 33 and the fuel pump mounting bracket 42.

  In FIGS. 12 and 13, the fuel pump mounting bracket 42 extends in the axial direction of the intake camshaft 13 and is attached to the upper surface of the rear side wall portion 31, and the left side wall from the first side wall portion 71. It includes a second side wall portion 72 that extends along the portion 33 and is attached to the upper surface of the left side wall portion 33, and a connecting wall portion 73 that connects the first side wall portion 71 and the second side wall portion 72. Is done.

  The second side wall portion 72 has a bearing support portion 72a formed in a semicircular shape so as to support the bearing portion 13b of the intake camshaft 13 from above. The left side wall 33 is formed with a bearing support portion 33A (see FIGS. 5 and 7) formed in a semicircular shape so as to support the bearing portion 13b of the intake camshaft 13 from below. Here, the bearing support portions 33A and 72a of the present embodiment constitute the bearing support portion of the present invention.

  A fuel pump mounting boss 74 is formed in the second side wall 72, and the fuel pump mounting boss 74 has a through hole 74 a into which the pump main body 51 of the fuel pump 41 is inserted. A flange 74b is formed at the opening end of the through hole 74a of the fuel pump mounting boss 74, and the flange 74b is fixed to the flange 51f of the pump body 51 by a bolt 76A (see FIG. 8).

  The flange 74 b is formed so as to be inclined with respect to the upper surfaces of the rear side wall portion 31, the front side wall portion 32 and the left side wall portion 33, that is, the upper surface of the cylinder head 11. Accordingly, in the state where the fuel pump 41 is attached to the fuel pump mounting bracket 42, the axis of the plunger 52 in the fuel pump 41 is inclined with respect to the upper surface of the cylinder head 11. This inclination angle is set in the range of 0 ° to 180 °. Thereby, the vertical height of the engine 1 can be shortened, and the vertical height of the vehicle can be shortened.

  The first side wall portion 71 is provided with fixed boss portions 75A and 75B in which through holes 75a and 75b are formed. Bolts 76B and 76C are inserted into the through holes 75a and 75b. Bolt holes 31A and 31B to which bolts 76B and 76C are fastened are formed in the rear side wall portion 31 (see FIG. 5). In the first side wall portion 71, the bolts 76B and 76C are inserted into the through holes 75a and 75b. Then, the bolts 76B and 76C are fitted into the bolt holes 31A and 31B, thereby being fixed to the rear side wall portion 31.

  The second side wall portion 72 is provided with a fixed boss portion 75C in which a through hole 75c is formed, and a bolt 76D is inserted into the through hole 75c. A bolt hole 33B to which a bolt 76D is fastened is formed in the left side wall 33 (see FIG. 5), and the bolt hole 33B is separated from the bolt hole 31B with respect to the axial direction of the intake camshaft 13.

Accordingly, the bolt 76C fitted into the bolt hole 31B is separated from the bolt 76C with respect to the bolt 76D fitted into the bolt hole 33B. Here, the bolts 76B to 76D of the present embodiment constitute a fastening member of the present invention.
The second side wall portion 72 is fixed to the left side wall portion 33 by inserting a bolt 76D into the through hole 75c and fitting the bolt 76C into the bolt hole 33B.

1, 2, and 8, in the top view of the cylinder head 11, the fuel pump mounting bracket 42 has a second side wall 72 that is a part of the fuel pump mounting bracket 42 as a bearing support portion 33 </ b> A (see FIG. 7). ) And the cylinder head 11 so as to overlap.
For this reason, the fuel pump 41 is attached to the fuel pump mounting bracket 42 so as to overlap the upper portion of the left side wall 33 in the top view of the cylinder head 11.

  12 and 13, a fastening portion 78 is formed on the second side wall portion 72. A through hole 78 a is formed in the fastening portion 78, and a case member described later is fixed to the fastening portion 78. In FIG. 1, the second side wall portion 72 of the present embodiment is located between the ignition coil 2 and the cam angle sensor 62.

  In FIGS. 1, 2, 4, 6, and 7, a vacuum pump 82 is attached to the second side wall 72 and the left side wall 33 of the fuel pump mounting bracket 42 via a case member 81. That is, the case member 81 of the present embodiment is provided between the vacuum pump 82 and the left side wall portion 33.

The vacuum pump 82 is fixed to the second side wall portion 72 together with the case member 81 by fitting bolts 76E into the through holes 78a of the second side wall portion 72 through the case member 81 (see FIG. 8).
4 and 6, the lower end of the case member 81 is fixed to the left wall 33 of the cylinder head 11 with a bolt 76F.

  The vacuum pump 82 is connected to the left end portion 13a of the intake camshaft 13 and is driven by the intake camshaft 13 to generate a negative pressure and supply the negative pressure to a brake booster or the like.

7 and 8, the sensing rotor 61 is accommodated in the case member 81, and the cylinder head 11 senses the cam chamber 63 that accommodates the pump drive cam 13 </ b> B by the left side wall portion 33 and the second side wall portion 72. It is partitioned into a detection chamber 64 that houses the rotor 61 and the cam angle sensor 62.
Here, the left side wall portion 33 of the present embodiment constitutes a partition wall and a side wall of the present invention, and the vacuum pump 82 constitutes an auxiliary machine of the present invention.

  A cooling water passage and a thermostat (not shown) are provided in the lower part of the case member 81 in contact with the left side wall 33, and a water jacket (not shown) formed inside the cylinder head 11 is provided in the cooling water passage. The flowing cooling water is discharged.

  This cooling water passage is partitioned from the detection chamber 64, which is a space above the case member 81 in which the left end portion 13 a of the intake cam shaft 13, the sensing rotor 61, and the cam angle sensor 62 are accommodated. Thereby, the cooling chamber does not flow from the cooling water passage to the detection chamber 64.

  In FIG. 1 and FIG. 2, the bolt 76 </ b> C that is spaced apart from the bearing support portion 33 </ b> A of the left side wall portion 33 in the axial direction of the intake cam shaft 13 is a case with respect to the direction orthogonal to the axial direction of the intake cam shaft 13. The cylinder head 11 is installed so as to overlap the member 81.

  In other words, in FIG. 5, the bolt hole 31 </ b> B into which the bolt 76 </ b> C is fitted is formed in the cylinder head 11 so as to overlap the case member 81 in the direction orthogonal to the axial direction of the intake camshaft 13.

  In FIG. 7, the pump drive cam 13 </ b> B is adjacent to the left side wall 33 inside the cam chamber 63, and the sensing rotor 61 is adjacent to the left side wall 33 inside the detection chamber 64. That is, the pump drive cam 13B and the sensing rotor 61 are provided so as to sandwich the left side wall portion 33, the second side wall portion 72, and the bearing portion 13b, and the bearing portion 13b is the first side wall portion 33 and the fuel pump mounting bracket 42. 2 is rotatably supported by the side wall 72.

  In FIG. 11, the cam angle sensor 62 is attached to the case member 81. The cam angle sensor 62 includes a main body 62A having a signal extraction coupler, and a detection element 62B that protrudes from the main body 62A toward the sensing rotor 61 and faces the sensing rotor 61 radially outward of the sensing rotor 61. ing. In addition, the detection element 62B of this Embodiment comprises the detection part of this invention.

  In the cam angle sensor 62, the protruding direction of the detecting element 62B from the main body 62A is orthogonal to the axial direction of the intake camshaft 13, and the detecting element 62B is in the moving direction A of the plunger 52 of the fuel pump 41. The protruding direction B is orthogonal.

  In the cam chamber 63 of the cylinder head 11 of the present embodiment, the contact surface between the intake cam 13A and the rocker arm 19, the contact surface between the exhaust cam 14A and the rocker arm (not shown), and the contact between the roller 52a of the plunger 52 and the pump drive cam 13B. Lubricating oil is supplied to the surface.

  For example, this oil passes through an oil passage (not shown) formed in the extending direction of the intake cam 13A and the exhaust cam 14A in the intake cam 13A and the exhaust cam 14A from the main oil gallery and is driven by the pump 52 and the roller 52a of the plunger 52. Supplied to the contact surface with the cam 13B.

Next, the operation will be described.
A sensing rotor 61 is provided at the left end 13 a of the intake camshaft 13, and the rotation angle of the intake camshaft 13 is detected by the cam angle sensor 62 detecting the protruding portion 61 </ b> A of the sensing rotor 61 when the intake camshaft 13 rotates. Is detected. The detection information of the cam angle sensor 62 is output to a controller (not shown), and the controller calculates the rotation speed and rotation angle of the intake camshaft 13 per unit time based on the detection information of the cam angle sensor 62.

  On the other hand, when the ignition plug 15 is ignited by the ignition coil 2, the cam angle sensor 62 may malfunction due to electromagnetic waves generated when the ignition coil 2 is ignited, and the cam angle sensor 62 is adversely affected by electromagnetic waves generated by the ignition coil 2. It is necessary not to receive.

  According to the engine 1 of the present embodiment, the cylinder head 11 rotatably supports the intake camshaft 13, and the cylinder head 11 is supported by the cam chamber 63 that houses the pump drive cam 13B, the sensing rotor 61, and the cam angle. It has a left side wall portion 33 that is partitioned into a detection chamber 64 that houses the sensor 62.

  Thereby, the ignition coil 2 and the cam angle sensor 62 can be electrically interrupted by the left side wall portion 33, and the cam angle sensor 62 can be prevented from being adversely affected by the electromagnetic waves of the ignition coil 2.

  Further, in the engine 1 of the present embodiment, the contact surface between the pump drive cam 13B and the roller 52a is lubricated by supplying lubricating oil to the contact surface between the pump drive cam 13B and the roller 52a of the plunger 52. Is done. This oil is scattered around after lubricating the contact surface between the pump drive cam 13B and the roller 52a.

  According to the engine 1 of the present invention, the cylinder head 11 has the left wall 33 that partitions the cylinder head 11 into a cam chamber 63 that houses the pump drive cam 13B and a detection chamber 64 that houses the sensing rotor 61 and the cam angle sensor 62.

  As a result, the detection chamber 64 that houses the cam angle sensor 62 can be isolated from the cam chamber 63 that houses the pump drive cam 13B, and oil that lubricates the roller 52a and the pump drive cam 13B is transferred from the cam chamber 63 to the detection chamber 64. It is possible to prevent scattering. For this reason, it is possible to reliably prevent the cam angle sensor 62 from detecting oil, and the rotation angle of the sensing rotor 61 can be detected by the cam angle sensor 62. As a result, the rotation angle of the intake camshaft 13 can be accurately detected.

  Further, in the engine 1 of the present embodiment, the bearing portion 13b of the intake camshaft 13 is a bearing support portion 33A formed on the left side wall portion 33 of the cylinder head 11 and the second side wall portion 72 of the fuel pump mounting bracket 42. It is rotatably supported by a bearing support portion 72a formed in the above.

Further, in the engine 1 of the present embodiment, the rocker arm 19 and the plunger 52 of the fuel pump 41 are installed so as to sandwich the intake camshaft 13. As a result, the direction of the load F1 applied from the rocker arm 19 to the intake camshaft 13 by the valve spring 22 and the direction of the load F2 applied from the plunger 52 to the intake camshaft 13 by the spring 54 are opposite to each other. Offset by F2.
Thus, it is not necessary to firmly fasten the fuel pump mounting bracket 42 to the cylinder head 11 with the bearing portion 13b of the intake camshaft 13 interposed therebetween.

  For this reason, the bolt 76C is installed apart from the bearing support portions 33A and 72a in the axial direction of the intake camshaft 13, and the second side wall portion 72 of the fuel pump mounting bracket 42 is a bearing when the cylinder head 11 is viewed from above. The fuel pump mounting bracket 42 can be attached to the cylinder head 11 so as to overlap the support portions 33A and 72a.

In this way, the fuel pump 41 can be installed above the left side wall 33 of the cylinder head 11, that is, the fuel pump 41 can be installed close to the side wall. In addition, by installing the fuel pump 41 above the left side wall 33 of the cylinder head 11, the pump drive cam 13B can be installed close to the left side wall 33, and the pump drive cam 13B on the intake cam shaft 13 The length with the bearing part 13b can be shortened.
As a result, the axial length of the intake camshaft 13 of the cylinder head 11 can be shortened, and the engine 1 can be downsized.

  Further, according to the engine 1 of the present embodiment, the case member 81 that houses the left end portion 13 a of the intake cam shaft 13 is attached to the left side wall portion 33 of the cylinder head 11, and the intake cam shaft 13 is attached to the case member 81. A vacuum pump 82 driven by the left end portion 13a of the intake camshaft 13 is attached to the outside in the axial direction.

  In addition to this, the bolt 76 </ b> C installed away from the bearing support portions 33 </ b> A and 72 a in the axial direction of the intake camshaft 13 overlaps the case member 81 in a direction orthogonal to the axial direction of the intake camshaft 13. The cylinder head 11 is installed.

  Thereby, in addition to being able to install the fuel pump 41 on the upper part of the left side wall portion 33, the bolts 76 </ b> C that are installed apart from the bearing support portions 33 </ b> A and 72 a in the axial direction of the intake cam shaft 13 By forming the cylinder head 11 so as to overlap the case member 81 in the direction orthogonal to the axial direction, the case member 81 can be brought close to a limit position where it does not interfere with the fuel pump 41 and the bolt 76C.

  For this reason, even when the case member 81 and the vacuum pump 82 are provided on the left side wall portion 33 of the cylinder head 11, the length in the axial direction of the intake cam shaft 13 of the cylinder head 11 can be shortened.

  In addition, according to the engine 1 of the present embodiment, the fuel pump mounting bracket 42 for mounting the fuel pump 41 to the cylinder head 11 is provided, and the fuel pump mounting bracket 42 extends in the axial direction of the intake camshaft 13. A first side wall portion 71 attached to the upper surface of the rear side wall portion 31 of the cylinder head 11, extending from the first side wall portion 71 along the left side wall portion 33, and fixed to the upper surface of the left side wall portion 33. The second side wall 72 includes a first side wall 71 and a connecting wall 73 that connects the second side wall 72.

  Thereby, the rigidity of the left side wall 33 can be increased by the amount of the fuel pump mounting bracket 42 provided, and the rigidity of the intake camshaft 13 can be increased more effectively. Thereby, it can prevent more effectively that the left end part 13a of the intake cam shaft 13 extended outside rather than the left side wall part 33 vibrates.

  Further, according to the engine 1 of the present embodiment, the vacuum pump 82 driven by the left end portion 13 a of the intake camshaft 13 is provided between the vacuum pump 82, the left side wall portion 33, and the second side wall portion 72. And a case member 81 that supports the vacuum pump 82 on the left side wall portion 33 and the second side wall portion 72, the sensing rotor 61 is accommodated inside the case member 81, and the case is arranged to face the sensing rotor 61. A cam angle sensor 62 is attached to the member 81.

  Thereby, the rigidity of the left side wall 33 can be further increased by the case member 81 that supports the vacuum pump 82 on the left side wall 33 and the second side wall 72, and the rigidity of the intake camshaft 13 can be increased more effectively. It is possible to more effectively prevent the left end portion 13a of the intake camshaft 13 extending outside the left side wall portion 33 from vibrating.

  Further, by providing the sensing rotor 61 and the cam angle sensor 62 on the existing case member 81 that supports the vacuum pump 82 on the left side wall 33, the sensing rotor 61 and the cam angle sensor 62 are installed on the engine 1. It is not necessary to provide a new space. Thereby, size reduction of the engine 1 can be achieved.

  Further, according to the engine 1 of the present embodiment, the cylinder head cover 12 attached to the upper part of the cylinder head 11 so as to cover the cylinder head 11 and the fuel pump mounting bracket 42, the cylinder head cover 12, and the ignition plug The second side wall 72 of the fuel pump mounting bracket 42 is positioned between the ignition coil 2 and the cam angle sensor 62.

  Thereby, the electromagnetic wave of the ignition coil 2 can be shielded by the second side wall part 72 of the fuel pump mounting bracket 42 in addition to the left side wall part 33, and the cam angle sensor 62 is adversely affected by the electromagnetic wave when the ignition coil 2 is ignited. Can be prevented. Therefore, the rotation angle of the intake camshaft 13 can be accurately detected by the cam angle sensor 62.

  In particular, the cylinder head 11 and the fuel pump mounting bracket 42 of the present embodiment are made of a metal material, and the cam angle is determined by the left side wall portion 33 of the cylinder head 11 and the second side wall portion 72 of the fuel pump mounting bracket 42. Since the sensor 62 and the ignition coil 2 are partitioned, the left side wall portion 33 and the second side wall portion 72 can more effectively shield the electromagnetic waves of the ignition coil 2.

  Further, since the cylinder head cover 12 of the present embodiment is made of a resin material, the cylinder head 11 and the fuel pump mounting bracket 42 are made of metal in order to enhance the electromagnetic wave shielding effect. Since the head cover 12 can be reduced in weight, the engine 1 can be reduced in weight.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 ... Engine (internal combustion engine), 11 ... Cylinder head, 13 ... Intake cam shaft, 13A ... Intake cam (cam lobe), 13B ... Pump drive cam, 13a ... Left end ( End of camshaft), 13b ... Bearing, 19 ... Rocker arm (valve lifter), 22 ... Valve spring (valve lifter), 33 ... Left side wall (side wall), 33A, 72a ... Bearing support part, 41 ... Fuel pump, 42 ... Fuel pump mounting bracket, 52 ... Plunger, 76B to 76D ... Bolt (fastening member), 81 ... Case member, 82 ... Vacuum Pump (auxiliary machine)

Claims (2)

A valve lifter attached to the cylinder head to open and close the valve;
A fuel pump mounting bracket fixed to the cylinder head by a plurality of fastening members so as to cover the cylinder head;
A fuel pump that is fixed to the fuel pump mounting bracket and pressurizes the fuel by moving the plunger; and
A camshaft having a bearing portion rotatably attached to a bearing support portion formed by the cylinder head and the fuel pump mounting bracket, a cam lobe for pressing the valve lifter, and a pump drive cam for pressing the plunger of the fuel pump; With
The valve lifter and the plunger are installed so as to sandwich the cam shaft,
An internal combustion engine configured such that an end portion of the cam shaft extends from the side wall to the outside and an accessory is driven by the end portion of the cam shaft;
At least one of the plurality of fastening members is spaced apart from the bearing support portion in the axial direction of the camshaft;
The internal combustion engine, wherein the fuel pump mounting bracket is attached to the cylinder head so that a part of the fuel pump mounting bracket overlaps the bearing support portion when the cylinder head is viewed from above. A case member that accommodates an end of the cam shaft is attached to the side wall of the cylinder head.
The auxiliary machine is attached to the case member on the outer side in the axial direction of the cam shaft,
The fastening member installed at a distance from the bearing support portion in the axial direction of the cam shaft is installed in the cylinder head so as to overlap the case member in a direction orthogonal to the axial direction of the cam shaft. The internal combustion engine according to claim 1.

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