JP2016070164A - Cylinder head for vehicle-mounted engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head equipped with a cam shifting mechanism, in which the mounting arrangement of an operation member is made compact without obstructing the deformation absorption of a bonnet by an operation member at the time when a collision object collides against a vehicle.SOLUTION: A cam shaft 20 on an intake side is positioned on the front side of a vehicle and an upper side of which is covered with a head cover 40. An electromagnetic actuator 30 on the intake side for sliding a cam element part 25 is attached in such a position to the head cover 40 as to be inclined on the vehicle rear side. The electromagnetic actuator 30 is equipped with a power feeding connector 35 extending over the head cover 40 toward the forward side of the vehicle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cylinder head of a vehicle-mounted engine.

  2. Description of the Related Art Conventionally, as a valve operating device for an engine, a plurality of cam portions having different nose shapes for one valve are provided, and by selecting a cam portion for opening and closing the valve from the plurality of cam portions, an intake valve and There is known an exhaust valve in which the opening amount, opening / closing timing, etc. of at least one of the exhaust valves can be switched according to the operating state of the engine (see, for example, Patent Document 1).

  In Patent Document 1, an electromagnetic actuator serving as an operation member for sliding a slide cam in a cam shifting mechanism is disposed laterally at an end portion in the width direction of a cylinder head in which an intake side cam shaft and an exhaust side cam shaft are arranged. A configuration that is arranged in a posture is disclosed. In addition, a configuration in which the electromagnetic actuator is arranged in a posture orthogonal to the width direction of the cylinder head is also disclosed.

US Patent Application Publication No. 2012/0031361

  However, when the electromagnetic actuator is disposed in a lateral orientation at the end of the cylinder head in the width direction as in the prior art, the oil in the head cover flows into the gap where the pin portion reciprocates, and the viscous resistance of the oil As a result, the operation responsiveness of the pin portion decreases. For this reason, there is a problem that the size of the electromagnetic actuator must be increased in order to increase the capability.

  By the way, in recent years, there are an increasing number of vehicles in which a multi-cylinder engine having a cylinder head disposed above a cylinder block is mounted sideways. And in such a vehicle, when a colliding object collides with a bonnet, the deformation | transformation absorption characteristic of a bonnet is requested | required.

  However, when the electromagnetic actuator is arranged in a posture orthogonal to the width direction of the cylinder head in consideration of the operation responsiveness of the electromagnetic actuator, there is a problem that the deformation absorption margin of the bonnet cannot be sufficiently secured.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent the operation member from absorbing deformation of the bonnet when a collision object collides with the vehicle in a cylinder head having a cam shifting mechanism. There is no need to make the mounting arrangement of the operation member compact.

  The present invention is directed to a cylinder head of a multi-cylinder vehicle-mounted engine having intake and exhaust camshafts arranged in the longitudinal direction of the vehicle and placed horizontally below the bonnet, and provides the following solution. It was.

That is, the first invention has a plurality of cam portions for valve opening / closing of a plurality of cylinders provided on the camshaft located in front of the vehicle among the intake-side and exhaust-side camshafts. A cam element portion coupled to the rotation direction and fitted to be slidable in the axial direction;
A head cover covering above the camshaft;
A plurality of electromagnetic operation members that switch the cam portion for opening and closing the valve by sliding the cam element portion in sliding contact with the inclined portion provided in the cam element portion;
The operation member is inclined to the vehicle rear side and attached to the head cover,
The operation member is provided with a power supply connector that extends above the head cover toward the front side of the vehicle.

  In the first invention, the operation member is inclined to the vehicle rear side and attached to the head cover, so that the deformation absorption allowance of the bonnet can be ensured as compared with the case where the operation member is attached to the head cover in a standing posture. it can. Further, by arranging the power supply connector of the operation member so that the upper portion of the head cover extends toward the front side of the vehicle, the power supply connector can also be arranged compactly without inhibiting deformation absorption of the bonnet.

According to a second invention, in the first invention,
The operation member is configured by an electromagnetic actuator having a pin portion that can move back and forth between an operating position that is in sliding contact with the inclined portion of the cam element portion and an inoperative position that is retracted from the inclined portion. It is what.

  In the second invention, the operation member is composed of an electromagnetic actuator, and the electromagnetic actuator is inclined to the rear side of the vehicle and attached to the head cover. It is possible to reduce the size by securing the operation response of the actuator.

According to a third invention, in the first or second invention,
A spark plug unit for each cylinder is disposed in front of the power supply connector,
Above the spark plug unit, a fuel supply common rail extending along the row direction of the cylinders is disposed.

  In the third aspect of the invention, the spark plug unit is disposed in front of the power supply connector, and the common rail is disposed above the spark plug unit. Can be arranged.

According to a fourth invention, in the third invention,
Between the intake-side and exhaust-side camshafts, a plurality of fuel injection nozzles for injecting fuel into the combustion chambers of the cylinders are disposed.
The plurality of fuel injection nozzles are connected to a plurality of fuel pipes that are branched from the common rail and routed around the plurality of operation members.

  In the fourth invention, since the plurality of fuel injection nozzles are disposed between the intake-side and exhaust-side camshafts, a plurality of fuel pipes branched from the common rail are provided with a plurality of operation members while ensuring serviceability. Can be compactly routed around.

A fifth invention is the fourth invention,
The fuel pipe is arranged so as to pass through a position lower than the upper end portion of the operation member.

  In the fifth invention, since the fuel pipe passes through a position lower than the upper end portion of the operation member, even if the bonnet is deformed, the bonnet interferes with the operation member before the fuel pipe. Can be protected.

A sixth invention is any one of the first to fifth inventions,
The inclined portion of the cam element portion is composed of end face cams respectively provided at both end portions in the axial direction of the cam element portion.

  In the sixth aspect of the invention, the cam shaft direction can be made compact by providing the end face cams at both end portions of the cam element portion in the axial direction.

  According to the present invention, the deformation absorption margin of the bonnet can be ensured by inclining the operation member toward the vehicle rear side and attaching it to the head cover. Further, by arranging the power supply connector of the operation member so that the upper portion of the head cover extends toward the front side of the vehicle, the power supply connector can also be arranged compactly without inhibiting deformation absorption of the bonnet.

It is a front view showing a schematic structure of a cylinder head of an engine concerning this embodiment. It is side surface sectional drawing for demonstrating arrangement | positioning of an electromagnetic actuator. It is a perspective view which shows the structure of an engine. It is a side view for demonstrating the arrangement position of fuel piping.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

  As shown in FIG. 1, the cylinder head 11 of the engine 10 includes a total of eight exhaust valves 15, two for each of the four cylinders 12, and return springs 17 that urge the exhaust valves 15 in the closing direction. Is provided. Further, an exhaust side camshaft 20 that opens the exhaust valve 15 against the urging force of the return spring 17 via the rocker arm 18 is provided at the upper part of the cylinder head 11.

  The configuration of the intake-side camshaft 20 that opens the intake valve (not shown) is substantially the same as that of the exhaust-side camshaft 20, and therefore only the configuration of the exhaust-side camshaft 20 will be described below.

  The camshaft 20 is rotatably supported by a bearing portion 21 provided at the center position of each cylinder 12 in the cylinder head 11 and is rotationally driven via a chain by a crankshaft (not shown).

  A cylindrical cam element portion 25 is spline fitted to the cam shaft 20. As a result, the cam element portion 25 is coupled to the cam shaft 20 in the rotational direction so as to rotate integrally, and is fitted so as to be slidable in the axial direction. The cam element portions 25 are arranged in a row in the cam shaft direction on the cam shaft 20 so as to correspond to the respective cylinders 12. The cam element portion 25 includes a first cam portion 25 a and a second cam portion 25 b that open and close the exhaust valve 15 by slidingly contacting the cam follower 18 a of the rocker arm 18.

  The first cam portion 25a and the second cam portion 25b are provided adjacent to each other. The first cam portion 25a is a cam portion that is selected at the time of low engine rotation, and has a lift amount larger than that of the second cam portion 25b. The 2nd cam part 25b is a cam part selected at the time of high engine rotation, and is formed smaller in lift amount than the 1st cam part 25a.

  The first cam portion 25a and the second cam portion 25b have a common base circle 25c, and nose portions having different lift amounts are provided on the base circle 25c with a slight phase difference. In addition, that the base circle 25c is common means that the base circle diameter of the base circle 25c of the 1st cam part 25a and the 2nd cam part 25b is the same.

  End cams 26 as inclined portions are respectively provided at both end portions of the cam element portion 25 in the axial direction. The end face cam 26 is formed such that the lift amount in the axial direction gradually increases from the reference surface with respect to the rotation direction, and returns to the reference surface at the lift end position.

  An electromagnetic actuator 30 as an operation member is disposed above the cam element portion 25 and at a position corresponding to the end face cams 26 on both sides in the cam shaft direction. The electromagnetic actuator 30 has a pin portion 31 that can project toward the camshaft 20 when energized. In a state where the electromagnetic actuator 30 is not energized, the pin portion 31 is held at the upper inoperative position by a permanent magnet provided inside the actuator. On the other hand, when the electromagnetic actuator 30 is energized, the pin portion 31 protrudes downward against the permanent magnet and advances to the operating position.

  When the pin portion 31 of the electromagnetic actuator 30 advances to the operating position, the tip portion of the pin portion 31 comes into sliding contact with the corresponding end face cam 26, and the cam element portion 25 is slid in the cam shaft direction.

  Specifically, when the electromagnetic actuator 30 on one end side of the cam element portion 25 is operated to bring the pin portion 31 into sliding contact with the end face cam 26 on one end side of the cam element portion 25, the cam element portion 25 is The cam follower 18a of the rocker arm 18 is slidably contacted with the first cam portion 25a. Further, when the electromagnetic actuator 30 on the other end side of the cam element portion 25 is operated and the pin portion 31 is brought into sliding contact with the end face cam 26 on the other end side of the cam element portion 25, the cam element portion 25 is moved to the cam shaft. It slides to the one end side of a direction, and it shifts so that the cam follower 18a of the rocker arm 18 may slidably contact with the 2nd cam part 25b. Thus, the cam part which opens and closes a valve among the 1st cam part 25a and the 2nd cam part 25b is switched by the shift to the axial direction of the cam element part 25. FIG.

  As shown in FIG. 2, the electromagnetic actuator 30 is attached to the upper wall portion of the head cover 40. Hereinafter, the mounting arrangement of the electromagnetic actuator 30 will be described.

  In the present embodiment, the engine 10 is horizontally installed below the bonnet 50, and an intake manifold 42 is connected to the front side of the cylinder head 11 in the vehicle (see FIG. 3). The intake-side camshaft 20 is disposed on the vehicle front side, and the exhaust-side camshaft 20 is disposed on the vehicle rear side. In FIG. 2, a virtual line illustrated below the hood 50 indicates a pedestrian protection line 51 that protects the pedestrian by absorbing deformation of the hood 50.

  The head cover 40 is disposed so as to cover the intake side and the exhaust side of the cam shaft 20. A plurality of electromagnetic actuators 30 are attached to an upper position of the upper wall portion of the head cover 40 above the intake-side camshaft 20 in a posture inclined toward the vehicle rear side. By arranging in such an inclined posture, the upper end portion of the electromagnetic actuator 30 does not exceed the pedestrian protection line 51, and the deformation absorption allowance of the bonnet 50 can be secured.

  Further, by inclining the intake-side electromagnetic actuator 30 toward the rear side of the vehicle, the pin portion 31 can move forward and backward with respect to the cam element portion 25 obliquely from above. Thereby, even if oil adheres to the electromagnetic actuator 30, since oil flows down along the inclination of the electromagnetic actuator 30, it can reduce that oil adheres.

  The electromagnetic actuator 30 on the intake side is provided with a power feeding connector 35 that extends above the head cover 40 toward the front side of the vehicle. Thereby, the power supply connector 35 can also be arranged in a compact manner without inhibiting the deformation absorption of the bonnet 50.

  A plurality of electromagnetic actuators 30 are attached to a position above the exhaust-side camshaft 20 on the upper wall portion of the head cover 40 so as to extend vertically. Thus, the exhaust-side electromagnetic actuator 30 is in a posture in which the pin portion 31 can be advanced and retracted from directly above the cam element portion 25.

  The electromagnetic actuator 30 on the exhaust side is provided with a power feeding connector 35 that extends obliquely downward toward the rear side of the vehicle.

  As shown in FIGS. 3 and 4, a plurality of fuel injection nozzles 45 for injecting fuel into the combustion chambers 13 (see FIG. 1) of each cylinder 12 are provided between the intake-side and exhaust-side camshafts 20. It is arranged.

  An ignition plug unit 46 of each cylinder 12 is disposed in front of the power supply connector 35 of the electromagnetic actuator 30 on the intake side. The spark plug unit 46 assists the self-ignition of the fuel injected into the combustion chamber 13 by the fuel injection nozzle 45, and gives a trigger for the self-ignition.

  Above the spark plug unit 46, a fuel supply common rail 47 extending along the column direction of each cylinder 12 is disposed. A plurality of fuel pipes 48 are connected to the common rail 47. A plurality of fuel pipes 48 branched from the common rail 47 are connected to the fuel injection nozzles 45 of the corresponding cylinders 12 respectively.

  Here, the fuel pipe 48 is routed along the periphery of the electromagnetic actuator 30 so as to pass through a position lower than the upper end portion of the electromagnetic actuator 30. Thereby, a plurality of fuel pipes 48 branched from the common rail 47 can be compactly routed around the plurality of electromagnetic actuators 30 while ensuring serviceability. Even when the bonnet 50 is deformed, the bonnet 50 interferes with the electromagnetic actuator 30 prior to the fuel pipe 48, so that the fuel pipe 48 can be protected.

  An in-cylinder pressure sensor 49 that detects the pressure in the combustion chamber 13 of each cylinder 12 is disposed behind the power supply connector 35 of the electromagnetic actuator 30 on the exhaust side. The pressure detected by the in-cylinder pressure sensor 49 is used for controlling the engine 10.

  As described above, according to the cylinder head 11 of the vehicle-mounted engine according to this embodiment, the electromagnetic actuator 30 is erected by attaching the electromagnetic actuator 30 on the intake side to the head cover 40 while being inclined to the vehicle rear side. Compared to the case where the hood 50 is attached to the head cover 40 in such a posture, the deformation absorption allowance of the bonnet 50 can be secured. Further, by arranging the power supply connector 35 of the electromagnetic actuator 30 so that the upper side of the head cover 40 extends toward the front side of the vehicle, the power supply connector 35 is also arranged in a compact manner without inhibiting deformation absorption of the bonnet 50. be able to.

<< Other Embodiments >>
About the said embodiment, it is good also as following structures.

  In the present embodiment, the configuration in which the end surface cams 26 as the inclined portions are provided at both end portions in the axial direction of the cam element portion 25 is described, but the present invention is not limited to this configuration. For example, it is good also as a structure which provided the end surface cam groove as an inclination part in the both ends of the axial direction of the cam element part 25, respectively.

  In this embodiment, a 4-cylinder, 4-valve DOHC engine has been described. However, an in-line 6-cylinder engine, a V-type multi-cylinder engine, a 4-cylinder 2-valve DOHC engine, a single-cylinder SOHC engine, a multi-cylinder SOHC engine, etc. It is possible to apply to various engines with different numbers of cylinders and valve trains.

  As described above, according to the present invention, in the cylinder head provided with the cam shifting mechanism, when the collision object collides with the vehicle, the operation member does not disturb the deformation absorption of the bonnet, and the operation member mounting arrangement is compact. It is extremely useful and has high industrial applicability because it is possible to obtain a highly practical effect.

DESCRIPTION OF SYMBOLS 10 Engine 11 Cylinder head 12 Cylinder 13 Combustion chamber 20 Cam shaft 25 Cam element part 25a 1st cam part 25b 2nd cam part 26 End surface cam (inclination part)
30 Electromagnetic actuator (operation member)
31 Pin part 35 Power supply connector 40 Head cover 45 Fuel injection nozzle 46 Spark plug unit 47 Common rail 48 Fuel piping 50 Bonnet

Claims (6)

A cylinder head of a multi-cylinder vehicle-mounted engine having intake and exhaust camshafts arranged in the longitudinal direction of the vehicle, and placed horizontally below the bonnet,
A plurality of cam portions for opening and closing valves of a plurality of cylinders, which are provided on the camshaft located in front of the vehicle among the intake-side and exhaust-side camshafts, and are coupled to the camshaft in a rotational direction; A cam element slidably fitted in the axial direction;
A head cover covering above the camshaft;
A plurality of electromagnetic operation members that switch the cam portion for opening and closing the valve by sliding the cam element portion in sliding contact with the inclined portion provided in the cam element portion;
The operation member is inclined to the vehicle rear side and attached to the head cover,
A cylinder head of a vehicle-mounted engine, wherein the operation member is provided with a power supply connector extending toward the front side of the vehicle above the head cover. In claim 1,
The operation member is configured by an electromagnetic actuator having a pin portion that can move back and forth between an operating position that is in sliding contact with the inclined portion of the cam element portion and an inoperative position that is retracted from the inclined portion. The cylinder head of a vehicle-mounted engine. In claim 1 or 2,
A spark plug unit for each cylinder is disposed in front of the power supply connector,
A cylinder head for a vehicle-mounted engine, characterized in that a fuel supply common rail extending along the row direction of each cylinder is disposed above the spark plug unit. In claim 3,
Between the intake-side and exhaust-side camshafts, a plurality of fuel injection nozzles for injecting fuel into the combustion chambers of the cylinders are disposed.
A cylinder head of a vehicle-mounted engine, wherein a plurality of fuel pipes branched from the common rail and routed around the plurality of operation members are connected to the plurality of fuel injection nozzles. In claim 4,
The cylinder head of a vehicle-mounted engine, wherein the fuel pipe is routed so as to pass through a position lower than an upper end portion of the operation member. In any one of claims 1 to 5,
The cylinder head of a vehicle-mounted engine, wherein the inclined portion of the cam element portion is constituted by end face cams respectively provided at both end portions in the axial direction of the cam element portion.

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