JP2018009479A - engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine in which a fuel pump device is attached to a cylinder block while ensuring collision safety.SOLUTION: An engine includes: a cylinder; a cylinder block 3 which has a crank case 7 under the cylinder; a crank shaft 21 provided in the inside of the crank case; and a fuel pump device press-feeding fuel with rotational force of the crank shaft. The fuel pump device has a cam shaft chamber 37 which is stored in parallel with the crank shaft, and stores a pump cam shaft 39 having a driving cam 45 rotation-driven by the rotational force of the crank shaft; and a pump body portion 41 which is inserted in the cam shaft chamber, and has a cam receiving portion 47 on one end side and a pump portion 49 on the other end side. The pump body is inclined to the cylinder block side than an extension line connecting an axial center of the crank shaft and the axial center of the pump cam shaft.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an engine in which a fuel pump device is installed.

  An engine mounted on an automobile (vehicle) includes an in-cylinder injection engine that injects fuel directly into a cylinder. An in-cylinder injection type engine has a high-pressure fuel pump device formed of a plunger pump provided in an engine body in order to inject fuel from an injector at a high pressure. Many of the fuel pump devices are connected to a fuel accumulator chamber to which an injector is connected, and the pump unit is driven by crankshaft output to pressurize fuel from the fuel tank and pump it to the fuel accumulator chamber.

The plunger pump constituting such a fuel pump device employs a structure in which a cam receiving portion and a pump portion driven by a displacement transmitted from the cam receiving portion are provided. Many fuel pump devices (plunger pumps) are provided in a cam cover at the upper part of the engine body, specifically, at the upper part of the cylinder head, and pump the fuel by the output of a camshaft disposed in the cam cover.
However, in this case, the fuel pump device has a structure in which a drive cam for driving the pump is provided on a part of the camshaft, the cam receiving portion is inserted into the cam cover to receive the drive cam, and the remaining pump portion is disposed outside the cam cover. Therefore, the overall height of the engine body becomes excessive. Moreover, there is a problem that there are many restrictions on providing a dedicated drive cam on the camshaft.

Therefore, it is conceivable to provide the fuel pump device on the side of the engine body, specifically on the cylinder block. However, if the fuel pump device that is simply commercialized is provided at the side of the cylinder block, there is a problem that the overall width of the engine becomes excessive.
On the other hand, in the engine for an outboard motor in which the crankshaft disclosed in Patent Document 1 is mounted vertically, the plunger pump is a fuel pump device using an engine case connected to a cylinder block. A technique for assembling is proposed. In this fuel pump device, a pump camshaft driven by crankshaft output and a cam receiving portion for receiving the camshaft drive cam are provided in an engine case which is a side portion of the engine body, and the pump portion is disposed outside the engine case. The structure of protruding and providing is used.

Japanese Patent Laid-Open No. 10-37757

By the way, the engine is mounted horizontally on the FF vehicle so that the crankshaft is directed in the vehicle width direction. Therefore, unlike the engine for the outboard motor of the cited document 1, the side of the cylinder block is the vehicle. Turn back and forth.
Moreover, the vehicle absorbs the impact applied in the case of a collision (front collision) between the front part of the vehicle where the radiator or the like is arranged and the side part of the adjacent engine body, that is, the side part of the cylinder block. It is required to form a crushable zone that can be made possible. In particular, since the fuel pump device handles fuel that may ignite, it is required to secure as much crushable length as possible on the side of the cylinder block facing in the vehicle longitudinal direction.

  Here, it is conceivable to apply the engine fuel pump device of Patent Document 1 to the engine. However, since the engine is used in an outboard motor in which a crankshaft is arranged in the vertical direction, a crushable zone is not secured on the side of a cylinder block like a vehicle. Moreover, even if the pump camshaft and the cam receiving portion are housed inside the engine body, it is difficult to secure a large crushable length because the pump portion protruding from the engine body to the outside becomes an obstacle.

  Therefore, an object of the present invention is to provide an engine in which a fuel pump device is attached to a cylinder block while ensuring collision safety.

  Aspects of the present invention include a cylinder block having a cylinder in which a piston can be reciprocated, a crankcase formed below the cylinder, a crankshaft provided in the crankcase, and rotation of the crankshaft. In an engine having a fuel pump device that is driven by force and pumps fuel, the fuel pump device is housed in parallel with the crankshaft, and a pump camshaft having a drive cam that is driven to rotate by the rotational force of the crankshaft A pump main body having a camshaft chamber for storing the gas and a pump portion inserted into the camshaft chamber and having a cam receiving portion for receiving a driving cam on one end side and driven by a displacement transmitted from the cam receiving portion on the other end side And the pump body is more sill than the extension line connecting the crankshaft axis and the pump camshaft axis. It is to be placed so inclined to block side.

  According to the engine of the present invention, the pump camshaft, the drive cam, and the cam receiving portion, which are the main parts of the fuel pump device, are incorporated into the cylinder block using the crankcase itself as a casing. It is short. Moreover, since the pump portion protruding outside is retracted to the side portion of the cylinder block, the length of the engine side portion can be further shortened.

Therefore, on the side of the cylinder block, it is possible to secure a large number of crushable lengths (crushable zones) for absorbing the applied impact by the vehicle body structure portion in the event of a collision (front collision).
Therefore, the fuel pump device can be attached to the cylinder block while ensuring collision safety.

(A) is a front view of the engine used as the aspect which concerns on the 1st Embodiment of this invention, (b) is a partial side view similarly. The front view which shows arrangement | positioning of each part of a fuel pump apparatus when it sees from the front of the same engine. The perspective view which shows each part of the fuel pump apparatus. The perspective view which carried out the partial cross section which shows the assembly | attachment state of the fuel pump apparatus. The perspective view of the engine which concerns on the aspect which concerns on the 2nd Embodiment of this invention.

Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.
FIG. 1 shows an outline of an engine mounted on an automobile (vehicle), FIG. 2 shows an arrangement of each part of the fuel pump device in the engine, and FIGS. 3 and 4 show a structure of each part of the fuel pump device. Yes.
FIGS. 1A and 1B show the appearance of the engine. In FIG. 1, 1 shows the engine body. The engine body 1 is a multi-cylinder engine in which the crankshaft 21 is mounted in the vehicle width direction of the vehicle, for example, an in-line 4-cylinder reciprocating engine.

The engine body 1 will be described. In the figure, 3 is a cylinder block. The cylinder block 3 is provided with four cylinders 5a to 5d (only part of which are shown in parallel) on the upper side, and a crankcase 7 is formed below the lower cylinders 5a to 5d. In each of the cylinders 5a to 5d, pistons 9a and 9b (only a part of which are shown) are accommodated so as to be able to reciprocate.
At the head end (upper end) of the cylinder block 3, a cylinder head 11 and a cam cover 13 in which an injector, a spark plug, a combustion chamber, and a valve system (all not shown) are assembled are provided in this order. An oil pump 15 is provided at the lower end (front side) of the crankcase 7. An oil pan 17 is provided at the end of the crankcase 7 so as to accommodate the oil pump 15. Incidentally, a chain case 19 is provided at the front end of the cylinder block 3 so as to cover the entire front portion.

The crankshaft 21 is provided in the crankcase 7 along the cylinder row direction. Of course, each part of the crankshaft 21 is rotatably supported by a bearing part (not shown) provided in the crankcase 7. That is, the crankshaft 21 is housed rotatably in the crankcase 7.
And each part of this crankshaft 21 and piston 9a, 9b in the said cylinders 5a-5d are connected via a connecting rod (not shown). Further, the crankshaft 21 is connected to the valve system of the cylinder head 11 via a chain member (not shown) housed in the chain case 19, and the valve system, injector, spark plug, pistons 9a, 9b From each operation, a combustion cycle (for example, intake, compression, explosion, exhaust, etc.) is formed in each of the cylinders 5a to 5d, and power obtained in the combustion cycle is output from the crankshaft 21.

  An end of the crankshaft 21 on the front side (engine front side) protrudes forward from the chain case 19. Among these, a crankshaft gear 22 is provided at a crankshaft portion located in the chain case 19 in addition to a chain sprocket (not shown) that meshes with the chain member. A crankshaft pulley 23 is provided at an end protruding out of the chain case 19.

  And between the crankshaft pulley 23 and the alternator 25 and the air conditioner compressor 27 arranged at the front part (end part) of the cylinder block 3, and various idler pulleys 29a to 29d (all correspond to auxiliary machines). In this structure, an endless belt member 31 is stretched over and the output of the crankshaft 21 is transmitted to each device. The alternator 25, the air conditioner compressor 27, and the idler pulleys 29a to 29d, which are auxiliary machines, are located on the side of the cylinder block 3, specifically on the side that is the intake side of the cylinder block 3 within a range that does not affect the engine parts. It is arranged overhanging towards. Therefore, the belt member 31 is suspended in a serpentine shape.

The crankshaft gear 22 meshes with the oil pump gear 15a that forms the input portion of the oil pump 15 installed at the lower end of the crankcase (within the chain case 19), and the oil pump 15 is driven by the rotational force (output) of the crankshaft 21. It has a structure.
A fuel pump device 35 is installed on the side of the cylinder block 3 of the engine body 1 as shown in FIGS. A plunger pump is used for the fuel pump device 35.

As shown in detail in FIGS. 3 and 4, the fuel pump device 35 uses a structure in which the main portion is accommodated in the crankcase 7 by using the crankcase 7.
Referring to FIG. 1, FIG. 3 and FIG. 4, reference numeral 37 denotes a camshaft chamber provided inside the side wall portion of the crankcase 7. The camshaft chamber 37 is a side wall portion disposed between the cylinder 5a disposed at the front portion (front side) of the engine body 1 and the axial center of the crankshaft 21 immediately below the cylinder 5a. For example, in a box shape. That is, the camshaft chamber 37 is a box whose periphery is surrounded by the front wall portion 8a, the peripheral wall portion 8b, and the rear wall portion 8c formed by the bulging portion 8 inside the front side wall (front side of the engine) of the crankcase 7. Formed from a shaped chamber (both partially shown in FIG. 4). With this structure, the camshaft chamber 37 is accommodated in the crankcase 7 in parallel with the crankshaft 21.

On the other hand, the fuel pump device 35 has a pump camshaft 39 as a main part and a pump body 41 that is reciprocally driven by cam displacement of the pump camshaft 39. Of these, the pump camshaft 39 is rotatably accommodated in the camshaft chamber 37, and the pump body 41 is inserted into the camshaft chamber 37 to constitute a plunger pump.
Specifically, for example, a through hole (not shown) is provided in the central portion of the front wall portion 8a of the camshaft chamber 37, and a bearing portion 37a (FIG. 4) is provided on the inner surface of the rear wall path portion of the camshaft chamber 37. Only shown). As shown in FIGS. 3 and 4, the pump camshaft 39 is constituted by a shaft member having a camshaft gear 43 at one end and a disk-like drive cam 45 formed at an intermediate portion. For example, the other end of the pump cam shaft 39 is inserted from the through hole of the front wall portion 8a until it reaches the bearing portion 37a, and the shaft portion in the through hole is rotatably supported by a bearing member (not shown). Installed by. With this attachment, as shown in FIGS. 3 and 4, the pump camshaft 39 is housed in the camshaft chamber 37 with only the camshaft gear 43 exposed to the outside (in the chain case 19). As a result, the pump camshaft 39 is accommodated in the camshaft chamber 37 in parallel with the crankshaft 21.

Incidentally, the camshaft chamber 37 and the pump camshaft 39 are arranged close to the cylinder block 3 side (direction approaching the cylinder 5a).
2 to 4, the pump main body 41 has a cam receiving portion 47 formed of a cam follower on one end side, for example, and is reciprocally driven by a displacement transmitted from the cam receiving portion 47 on the other end side. A drive type pump unit 49 is provided. More specifically, the pump unit 49 includes a plunger pump unit configured by, for example, a plunger (both not shown) being reciprocally moved in a cylinder unit. The cam receiving portion 47 is provided at the tip of an operating rod 49a that extends from the plunger and protrudes from one end side of the cylinder portion of the plunger pump portion. On the other end side of the cylinder portion opposite to the cam receiving portion 47, a mounting flange 53 and suction / discharge port portions 55a and 55b are provided.

  The pump main body 41 is attached by being inserted into the camshaft chamber 37. That is, the pump main body 41 has the cam receiving portion 47 placed on the drive cam 45 from an installation hole portion 8d (FIG. 4) formed in the upper portion of the peripheral wall portion 8b of the camshaft chamber 37, which is located immediately above the drive cam 45. It is inserted into the camshaft chamber 37 until it abuts against the cam surface, and the mounting flange 53 is fixed to the seat surface portion 8e formed at the peripheral edge of the installation hole 8d, for example, by bolting. Incidentally, the pump body 41 is inserted from the direction orthogonal to the pump camshaft 39. As a result of this installation, the pump body 41 has a plunger in which the cam receiving portion 47 is disposed in the camshaft chamber 37 as shown in FIGS. 3 and 4, and has a mounting flange 53, suction / discharge ports 55a, 55b, and the like. The pump portion (pump portion 49) side is installed in a linear posture protruding out of the camshaft chamber 37. That is, the pump main body 41 has a structure in which the pump camshaft 39, the cam receiving portion 47, and the operating rod 49a as the main parts are housed in the crankcase 7 by using the crankcase 7 as a casing. Attach the unit compactly.

  Further, the pump body 41 is arranged to be inclined toward the cylinder block 3 with respect to the extension line C connecting the axis A of the crankshaft 21 and the axis B of the pump camshaft 39 as shown in FIG. The structure prevents the cylinder block 3 from projecting to the side. The pump main body 41 is retracted to the cylinder block 3 side as much as possible in combination with the pump camshaft 39 as a whole.

  In particular, the pump body 41 is stretched toward the intake side of the cylinder block 3 as shown in FIGS. 1 and 2 so as to be protected from contact with a vehicle body structure (a radiator or the like) at the time of a vehicle collision (front collision). Of the auxiliaries that have come out, they are arranged closer to the cylinder block 3 than the position of the foremost end of the auxiliaries that protrude to the most side, for example, the idler pulley 29a arranged in the middle stage. In other words, even if there is a vehicle body structure that enters the engine side from the front of the vehicle at the time of a collision, the approaching object comes into contact with the idler pulley 29a first to avoid contact with the pump body 41. Yes.

  The camshaft gear 43 of the pump body 41 is engaged with the crankshaft gear 22 at the end of the crankshaft (in the chain case 19), and the pump 49 is driven by the rotational force of the crankshaft 21. For this transmission, a gear structure (constant speed rotation mechanism) with a gear ratio of “1: 1” is used. By rotating the pump camshaft 39 at a constant speed with the crankshaft 21, the pump main body 41 is properly fitted. Driven by.

The suction port 55a of the pump unit 49 is connected to the fuel tank (not shown), and the discharge port 55b is connected to a fuel pressure storage chamber (not shown) connected to the injector. Thus, fuel from a fuel tank (not shown) is pressurized and fed to the fuel accumulator chamber (high pressure).
In particular, when both the pump camshaft 39 and the oil pump 15 are driven by the rotational force (output) of the crankshaft 21, if the pump camshaft 39 and the oil pump 15 are in similar positions, Here, the reaction force is biased and causes vibration or the like. Here, as shown in FIG. 2, an extension line α (first extension) passing through the axis α of the cylinder 5 a and the center B of the crankshaft 21 in the cylinder block 3. Line) and an extension line β (second extension line) perpendicular to the extension line α at the center B of the crankshaft 21, and the pump camshaft 39 on the intake side and the upper stage side of the engine body 1 on one side. And the oil pump 15 is disposed on the exhaust side and the lower side of the engine body 1 on the other side, the crankshaft gear 22 to the camshaft gear 43, The reaction force acting when the power is transmitted from the shaft gear 22 to the oil pump gear 15a is offset.

Next, the operation of the fuel pump device assembled in the cylinder block 3 will be described with reference to FIG.
When the engine is started and the crankshaft 21 is rotationally driven, the rotational force of the crankshaft 21 is transmitted to the pump camshaft 39 through the crankshaft gear 22 and the camshaft gear 43. Then, the drive cam 45 of the pump cam shaft 39 is rotated, and the cam receiving portion 47 that is in contact with the drive cam 45 is displaced. The cam displacement transmitted from the cam receiving portion 47 is transmitted to the plunger (not shown) via the operating rod 49a. As a result, the plunger is driven to reciprocate, pressurizing the fuel supplied from the fuel tank side, and pumping it to a fuel accumulator chamber (not shown) mounted on the cylinder block 3. High-pressure fuel stored in the fuel storage chamber is injected from an injector (not shown) into a combustion chamber (not shown).

Incidentally, the rotational force of the crankshaft 21 is also transmitted to the oil pump 15 through the crankshaft gear 22 and the oil pump gear 15a to drive the oil pump 15.
2 indicate the rotation directions of the crankshaft gear 22, the oil pump gear 15a, and the camshaft gear 43, respectively.
As described above, the fuel pump device 35 that pumps high-pressure fuel accommodates the pump camshaft 39 in the camshaft chamber 37 that is housed in the crankcase 7 in parallel with the crankshaft 21, and the pump body 41 in the camshaft chamber 37. The pump camshaft 39, the drive cam 45, and the cam receiving portion 47, which are the main parts of the fuel pump device 35, are inserted into the cylinder block 3 by using the crankcase itself of the cylinder block 3 as a casing. Since the housing structure is used, the engine side portion length (engine width dimension) can be short as indicated by L1 in FIG. This is because the fuel pump device 35 does not require a special casing.

In addition, since the pump body 41 is arranged to be inclined toward the cylinder block 3, the pump portion protruding out of the camshaft chamber 37 has an angle θ that is inclined as shown in FIG. Since it is retracted to the side part of the block 3, the engine side part length (engine width dimension) can be further shortened.
As a result, in the case of an FF vehicle, an engine mounted horizontally on the vehicle is added at the time of a collision (front collision) from the direction of arrow F shown in FIG. 1 on the side of the cylinder block 3 facing the vehicle longitudinal direction. Many crushable lengths (crushable zones) that absorb the impact by the vehicle body structure can be secured.

Therefore, the fuel pump device 35 can be attached to the side portion of the cylinder block 3 while ensuring collision safety.
In particular, by arranging the pump cam shaft 39 close to the cylinder block 3 side (direction approaching the cylinder), it is possible to secure a larger number of crushable lengths (crushable zones).

  Moreover, the pump portion that protrudes out of the camshaft chamber 37 is an auxiliary machine that protrudes from the cylinder block 3 as shown in FIG. 2, specifically, an idler pulley 29a that protrudes most laterally from the cylinder block 3 ( Auxiliary machine) (L2 in FIG. 2) is positioned closer to the cylinder block 3 side (L1 <L2), so that a vehicle body structure that enters the engine side from the front of the vehicle in the event of a collision. Even if there is an intrusion, the entering object first comes into contact with the idler pulley 29a to avoid contact with the pump body 41, so that the safety of the pump body 41 can be achieved.

  The pump camshaft 39 and the oil pump 15 driven by the rotational force of the crankshaft 21 include an extension line α (first extension line) passing through the axis of the cylinder 5a and the center B of the crankshaft 21, and the crankshaft 21. Since the pump camshaft 39 is arranged on one side and the oil pump 15 is arranged on the other side with the extension line β (second extension line) orthogonal to the extension line α at the center B of the crankshaft gear The reaction force acting when power is transmitted from the pump 22 to the pump camshaft 39 and the oil pump 15 can be offset, and the occurrence of vibration due to the reaction force can be prevented.

FIG. 5 shows a second embodiment of the present invention.
In the embodiment, the present invention is applied to an engine body 1a of a three-cylinder engine, not a four-cylinder engine.
In the case of the engine body 1a of a three-cylinder engine, it is required to reduce the inertial force and couple due to the movement of a piston and a crankshaft (both not shown).

In the present embodiment, the fuel pump device 35 is used as it is so that the inertia force and couple can be reduced.
That is, the fuel pump device 35 has a pump cam shaft 39 that rotates at the same speed as the crankshaft 21.
Therefore, in the present embodiment, a balancer shaft 63 having a balance weight 61 is connected to the end of the pump camshaft 39, and the constant speed rotation of the pump camshaft 39 is used as it is. And rotating at a constant speed. As a result, the fuel pump device 35 can be used as it is, and the balance weight 61 can be properly rotated corresponding to the three-cylinder engine, and the inertial force and couple force associated with the movement of the piston and crankshaft (both not shown). Can be reduced. Incidentally, the bulging portion 8 (camshaft chamber) is extended by the addition of the balancer shaft 63.

However, in FIG. 5, the same parts as those in FIG.
It should be noted that the configurations and combinations thereof in the above-described embodiments are examples, and it is needless to say that additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present invention. Nor. Further, the present invention is not limited by the above-described embodiment, and it is needless to say that the present invention is limited only by the “claims”. For example, in the above-described embodiment, the pump camshaft is driven by the transmission mechanism using the gear. However, the present invention is not limited to this, and the rotation of the crankshaft to the pump camshaft is performed at a constant speed using a chain member or the like. You may make it tell.

DESCRIPTION OF SYMBOLS 1 Engine main body 3 Cylinder block 5a, 5b Cylinder 7 Crankcase 9a, 9b Piston 15 Oil pump 21 Crankshaft 29a Idler pulley (auxiliary machine)
35 Fuel Pump Device 37 Cam Shaft Chamber 39 Pump Cam Shaft 41 Pump Body 45 Drive Cam 47 Cam Receiving Portion 49 Pump Portion 63 Balancer Shaft

Claims (5)

A cylinder block having a cylinder in which a piston can be reciprocated and a crankcase formed below the cylinder;
A crankshaft provided inside the crankcase;
A fuel pump device that is driven by the rotational force of the crankshaft to pump fuel; and
In an engine equipped with
The fuel pump device comprises:
A camshaft chamber that houses a pump camshaft that is housed in parallel with the crankshaft and has a drive cam that is rotationally driven by the rotational force of the crankshaft;
A pump body having a cam receiving portion that receives the drive cam on one end side and a pump portion that is driven by a displacement transmitted from the cam receiving portion on the other end side. ,
The engine, wherein the pump main body portion is disposed to be inclined toward the cylinder block side with respect to an extension line connecting the axis of the crankshaft and the axis of the pump camshaft.   The engine according to claim 1, wherein the pump camshaft is arranged close to the cylinder block side. The cylinder block has an auxiliary device arranged to protrude from the cylinder block,
3. The engine according to claim 1, wherein the pump main body portion is disposed closer to the cylinder block side than a position of a foremost end of the protruding auxiliary machine. The end of the crankcase has an oil pump driven by the rotational force of the crankshaft,
The cylinder block includes a first extension line passing through the cylinder axis and the center of the crankshaft, and a second extension line perpendicular to the first extension line at the center of the crankshaft, respectively. The engine according to any one of claims 1 to 3, wherein the pump camshaft is disposed on a side and the oil pump is disposed on the other side.   The engine according to claim 1, wherein the pump camshaft is provided with a balancer shaft at an end of the pump camshaft.

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