JP2008019842A - Fuel pump supporting structure of internal combustion engine and pump supporting bracket used in supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel pump supporting structure of an internal combustion engine capable of supporting a fuel pump in an upper part of a cylinder head with high supporting rigidity and a pump supporting bracket used in the supporting structure. <P>SOLUTION: The pump supporting bracket 9 is mounted to be laid across a plurality of bearing parts 207 and 208 in a camshaft housing 38R, and a high pressure fuel pump 110 is supported on an upper surface of the pump supporting bracket 9. An oil jet for injecting oil to a lifter of the high pressure fuel pump 110 is formed on the pump supporting bracket 9. An oil reservoir for immersing a driving cam for driving the high pressure fuel pump 110 in the oil is formed in the bearing part 207. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is applied to an internal combustion engine such as an in-cylinder direct injection engine, for example, and supports a fuel pump for boosting fuel supplied to a fuel injection valve (injector) and a pump support bracket used for the support structure. Concerning. In particular, the present invention relates to a measure for supporting a fuel pump with high support rigidity.

  2. Description of the Related Art Conventionally, in an engine where high pressure is required for fuel supplied to an injector, such as an in-cylinder direct injection engine, the fuel sent from the fuel tank is pressurized with a high-pressure fuel pump and directed to the injector. To supply.

  Specifically, as a configuration of a fuel supply system provided with this type of high-pressure fuel pump, as disclosed in the following Patent Document 1 and Patent Document 2, a feed pump that feeds fuel from a fuel tank, this feed pump Is provided with a high-pressure fuel pump for pressurizing the fuel sent out by the fuel tank and a delivery pipe for storing the fuel pressurized by the high-pressure fuel pump. A plurality of injectors are connected to the delivery pipe. As a result, the high-pressure fuel stored in the delivery pipe is injected from the opened injector toward the combustion chamber as the injector opens.

  In the high-pressure fuel pump, a plunger is inserted in the cylinder. The plunger receives a pressing force from the drive cam via the lifter and reciprocates in the cylinder, and adds the fuel sucked into the pressurizing chamber. It comes to press. In addition, a spill valve is provided as a mechanism for adjusting the fuel discharge amount in this type of high-pressure fuel pump. The spill valve includes a low-pressure fuel pipe serving as a fuel supply path from the feed pump and a pressurizing chamber of the high-pressure fuel pump. The fuel discharge amount is adjusted by switching between a communication state and a non-communication state.

By the way, as described above, the high pressure fuel pump is configured such that the plunger reciprocates within the cylinder, and therefore, vibration is generated along with the reciprocating movement of the plunger when the pump is driven. For this reason, it is desirable to ensure high rigidity as a support structure for the high-pressure fuel pump. An example of a conventional support structure for a high-pressure fuel pump is disclosed in Patent Document 3 below. In Patent Document 3, a substantially cylindrical bracket is fixed to the upper part of a cylinder head, and a high-pressure fuel pump is mounted on the bracket.
JP 2000-297710 A JP 2003-328847 A JP 2000-291503 A

  However, the conventional high pressure fuel pump support structure is not configured to have a high support rigidity capable of sufficiently absorbing the vibration generated with the reciprocating movement of the plunger. is there. The reason will be described below.

  In general, a high-pressure fuel pump receives a pressing force from a driving cam formed integrally with a camshaft (for example, an intake camshaft) for driving a valve mechanism of an engine, so that a plunger reciprocates. It is configured to be performed. For this reason, the high-pressure fuel pump is disposed at the upper part of the cylinder head.

  However, since the cylinder head accommodates various parts constituting the valve operating mechanism, most of the inside is an opening. Therefore, it is difficult for the cylinder head to have a portion that can support the high-pressure fuel pump with high support rigidity, and the bracket is simply fixed to the upper portion of the cylinder head (for example, the frame portion of the cylinder head) as described in Patent Document 3 above. It was difficult to support the high-pressure fuel pump with high support rigidity capable of sufficiently absorbing the above vibration.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a fuel pump support structure for an internal combustion engine that can be supported with high support rigidity when the fuel pump is supported on the upper part of the cylinder head. And a pump support bracket used for the support structure.

-Solving principle-
The solution principle of the present invention taken to achieve the above object is to realize a fuel pump support structure that straddles a plurality of bearing parts by using a bearing part that is a relatively rigid part of each part of the cylinder head. Thus, the fuel pump can be supported with high support rigidity without greatly changing the configuration of the cylinder head.

-Solution-
Specifically, the present invention is premised on a fuel pump support structure for an internal combustion engine for supporting a fuel pump for boosting the fuel supplied toward the fuel injection valve on the cylinder head. With respect to this fuel pump support structure, bearings for rotatably supporting the camshaft on the cylinder head are provided at a plurality of locations in the cylinder row direction, and at least two of the plurality of bearings are provided. The pump support bracket is provided so as to extend over the bearing and fixedly supported by these bearings, and the fuel pump is attached to the pump support bracket.

  Due to this specific matter, the fuel pump is supported by a plurality of bearing portions via a pump support bracket. Since each bearing portion rotatably supports a camshaft that receives a reaction force from the valve mechanism, it is a portion that has a relatively high rigidity in each portion of the cylinder head. In the above configuration, since the fuel pump is supported across a plurality of the bearing portions, the support rigidity can be sufficiently high. As a result, the fuel pump can be stably driven, and vibrations generated by driving the fuel pump can be sufficiently absorbed, and the vibrations are transmitted to other members. Can be suppressed.

  More specifically, the configuration of the pump support bracket includes the following. That is, the bearing portion of the cylinder head is formed with a head-side bearing surface that becomes the bearing surface of the camshaft, and the pump support bracket has a bracket-side bearing surface similar to the portion facing the head-side bearing surface. Form. The bracket-side bearing surface is configured to rotatably support the camshaft together with the head-side bearing surface.

  According to this configuration, the function as a conventional cam cap (a member for pressing the upper side of the camshaft) can be used as the pump support bracket. For this reason, for example, when the pump support bracket is disposed across two bearing portions, the pump support bracket functions as two cam caps, and the pump support bracket is disposed across the three bearing portions. In this case, the pump support bracket functions as three cam caps. That is, since the cam cap is not required in the portion where the pump support bracket is disposed, the number of parts can be reduced and the engine can be downsized by effectively using the space.

  Further, as a configuration in which the function of improving the lubricity of the sliding contact portion between the camshaft and the fuel pump (specifically, the lifter of the fuel pump) is added to the pump support bracket, the following can be mentioned. In other words, a plunger that is inserted into the fuel pump so as to be reciprocally movable in the cylinder to form a pressurizing chamber, and a pressing force from a drive cam integrally formed on the camshaft is applied to the plunger to pressurize the chamber. And a lifter that moves the plunger in the direction of contraction. And it is set as the structure which formed the oil supply path for supplying lubricating oil toward the sliding contact part of the said lifter and a drive cam in the pump support bracket.

  According to this configuration, for example, by connecting a part of the lubricating oil path in the internal combustion engine to the oil supply path of the pump support bracket, the lubricating oil flowing into this oil supply path is supplied to the sliding contact portion between the lifter and the drive cam ( Will be injected). As a result, the sliding resistance between the lifter and the drive cam is greatly reduced, the mechanical loss can be reduced, and the fuel pump can be driven with high efficiency. Further, by effectively using the pump support bracket, it is possible to prevent an increase in the number of parts without requiring a new member for forming the oil supply passage.

  Further, examples of the configuration for reducing the mechanical loss due to the lubricating oil include the following. That is, the fuel pump is driven by receiving a pressing force from a drive cam formed integrally with the camshaft, and a bearing portion (a bearing portion of the cylinder head) is provided on one of the cylinder head and the pump support bracket. ) Is integrally formed with a lubricating oil reservoir for storing the lubricating oil supplied at a position facing the outer peripheral surface of the drive cam.

  According to this configuration, the drive cam rotates while the outer peripheral surface is immersed in the lubricating oil stored in the lubricating oil reservoir, and the sliding contact with the outer peripheral surface of the drive cam, that is, the lifter of the fuel pump. The surface is always in a well-lubricated state, and the effect of reducing friction at this sliding portion can be obtained with certainty.

  Further, when the fuel pump has an arrangement structure in which the tip (upper end) portion of the fuel pump protrudes outside from the cylinder head cover, the following structure is given as a configuration for sealing the internal space (so-called cam chamber) of the cylinder head cover. It is done. That is, a cylinder head cover in which an opening as a fuel pump installation space is formed on the upper side of the cylinder head. In addition, an annular seal member is provided at the edge of the opening of the cylinder head cover so as to seal the inner space of the cylinder head cover, which is disposed over the entire periphery. The seal member is formed with a vibration absorbing lip portion for preventing vibration generated by the fuel pump from being transmitted to the cylinder head cover.

  According to this, the vibration of the fuel pump is suppressed from being absorbed by the lip portion of the seal member and transmitted to the cylinder head cover while obtaining a sealing function in which the internal space of the cylinder head cover does not communicate with the outside. . As a result, it is possible to prevent the generation of abnormal noise (large vibration noise caused by the vibration of the fuel pump being transmitted to the cylinder head cover and functioning as a speaker) due to the vibration of the cylinder head cover.

  The pump support bracket used in the fuel pump support structure described in any one of the above-described solutions is also within the scope of the technical idea of the present invention. That is, the pump support bracket is configured to support the fuel pump in a state of being disposed across at least two bearing portions of the plurality of bearing portions of the cylinder head and fixedly supported by these bearing portions.

  In the present invention, the fuel pump is supported by a pump support bracket disposed across a plurality of bearing portions using the bearing portion of the cylinder head. For this reason, it is possible to obtain a sufficiently high support rigidity for the fuel pump, to sufficiently absorb the vibration generated as the fuel pump is driven, and to transmit this vibration to other members. I can stop.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the fuel pump support structure according to the present invention is applied to an automotive V-type 8-cylinder engine (internal combustion engine) will be described.

-Description of overall engine configuration-
Before describing the fuel pump support structure, the overall configuration of the engine on which the fuel pump is mounted will be described.

  FIG. 1 is a diagram showing a schematic configuration inside an engine when a V-type engine E according to the present embodiment is viewed from a direction along the axis of a crankshaft C. FIG. 2 is a system configuration diagram showing an outline of the engine E and the intake / exhaust system.

  As shown in these drawings, the V-type engine E has a pair of banks 2L and 2R protruding in a V-shape at the upper part of the cylinder block 1. Each bank 2L, 2R includes a cylinder head 3L, 3R installed at the upper end of the cylinder block 1 and a head cover 4L, 4R attached to the upper end thereof. The cylinder block 1 is provided with a plurality of cylinders 5L, 5R,... (For example, four in each bank 2L, 2R) with a predetermined sandwich angle (for example, 90 °). The pistons 51L, 51R,... The pistons 51L, 51R,... Are connected to the crankshaft C through connecting rods 52L, 52R,. Further, a crankcase 6 is attached to the lower side of the cylinder block 1, and a space extending from the lower part in the cylinder block 1 to the inside of the crankcase 6 is a crank chamber 61. An oil pan 62 serving as an oil reservoir is disposed further below the crankcase 6.

  The cylinder heads 3L and 3R are respectively assembled with intake valves 32L and 32R for opening and closing the intake ports 31L and 31R and exhaust valves 34L and 34R for opening and closing the exhaust ports 33L and 33R. The valves 32L, 32R, 34L, and 34R are opened and closed by the rotation of the cam shafts 35L, 35R, 36L, and 36R disposed in the cam chambers 41L and 41R formed between the head covers 4L and 4R. To be done.

  Further, the cylinder heads 3L and 3R of the engine E according to the present embodiment have a divided structure. Specifically, the cylinder heads 3L and 3R are constituted by cylinder head bodies 37L and 37R attached to the upper surface of the cylinder block 1 and camshaft housings 38L and 38R assembled on the upper side of the cylinder head bodies 37L and 37R. The reason why such a divided structure is adopted is to improve the assembly workability of the engine component parts. That is, the intake valve 32L, 32R, the exhaust valve 34L, 34R, and various components of the valve operating mechanism are assembled to the cylinder head bodies 37L, 37R, while the camshafts 35L, 35R, 36L, 36R are assembled to the camshaft housings 38L, 38R. Let me support you. Thereafter, the camshaft housings 38L and 38R are integrally assembled on the upper side of the cylinder head main bodies 37L and 37R by means such as bolting to complete the cylinder heads 3L and 3R in which the valve mechanisms are assembled. Thereby, the assembly workability | operativity of an engine component becomes favorable.

  On the other hand, intake manifolds 7L and 7R corresponding to the banks 2L and 2R are disposed on the inner side (between banks) of the banks 2L and 2R, and the downstream ends of the intake manifolds 7L and 7R correspond to the respective banks. It communicates with the intake ports 31L, 31R,. The intake manifolds 7L and 7R are connected to an intake pipe 73 having a surge tank 71 (see FIG. 2) common to each bank and a throttle valve 72, and an air cleaner 74 is provided upstream of the intake pipe 73. Is provided. Thereby, the air introduced into the intake pipe 73 from the air cleaner 74 is introduced into the intake manifolds 7L and 7R through the surge tank 71.

  Port injection injectors (port injection fuel injection valves) 75L and 75R are respectively provided in the intake ports 31L and 31R of the cylinder heads 3L and 3R. During fuel injection from the port injection injectors 75L and 75R, The air introduced into the intake manifolds 7L and 7R and the fuel injected from the port injectors 75L and 75R are mixed to form an air-fuel mixture, and the combustion chambers 76L and 76R are opened as the intake valves 32L and 32R are opened. Will be introduced.

  The engine E according to the present embodiment also includes in-cylinder direct injection injectors (in-cylinder direct injection fuel injection valves) 78L and 78R. During fuel injection from the in-cylinder direct injection injectors 78L and 78R, The fuel is directly injected into the combustion chambers 76L and 76R.

  As an example of the fuel injection mode of the port injectors 75L, 75R and in-cylinder direct injection injectors 78L, 78R, fuel injection from both the injectors 75L, 75R, 78L, 78R is performed when the engine E is under low and medium loads. A homogeneous air-fuel mixture is generated to improve fuel efficiency and reduce emissions. Further, when the engine E is under a high load, fuel injection is performed only from the in-cylinder direct injection injectors 78L and 78R so as to improve the charging efficiency by the intake air cooling effect and to suppress the knocking. The fuel injection mode of these injectors 75L, 75R, 78L, 78R is not limited to this.

  The fuel supply system to the port injectors 75L and 75R and the in-cylinder direct injectors 78L and 78R will be described later.

  Spark plugs 77L and 77R are disposed at the tops of the combustion chambers 76L and 76R. In the combustion chambers 76L and 76R, the combustion pressure of the air-fuel mixture accompanying the ignition of the spark plugs 77L and 77R is transmitted to the pistons 51L and 51R, causing the pistons 51L and 51R to reciprocate. The reciprocating motion of the pistons 51L and 51R is transmitted to the crankshaft C via the connecting rods 52L and 52R, converted into rotational motion, and taken out as the output of the engine E. The camshafts 35L, 35R, 36L, and 36R are driven to rotate by the power extracted from the crankshaft C being transmitted by the timing chain, and by this rotation, the valves 32L, 32R, 34L, and 34R are opened and closed. Let it be done.

  The air-fuel mixture after combustion becomes exhaust gas and is discharged to the exhaust manifolds 8L and 8R when the exhaust valves 34L and 34R are opened. Exhaust pipes 81L and 81R are connected to the exhaust manifolds 8L and 8R, respectively, and catalytic converters 82L and 82R incorporating a three-way catalyst or the like are attached to the exhaust pipes 81L and 81R. By passing the exhaust gas through the catalytic converters 82L and 82R, hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxide components (NOx) contained in the exhaust gas are purified. . Further, the downstream ends of the exhaust pipes 81L and 81R are joined and connected to the muffler 83.

-Fuel supply system-
Next, a fuel supply system for supplying fuel to the port injectors 75L and 75R and the in-cylinder direct injectors 78L and 78R will be described with reference to FIG. FIG. 3 is a diagram schematically showing the structure of the fuel supply system 100 provided in one bank of the engine E according to this embodiment. That is, in the engine E, the same fuel supply system 100 is provided in each of the banks 2L and 2R. Here, the fuel supply system 100 provided in the right bank 2R will be described as a representative.

  The fuel supply system 100 includes a feed pump 102 that feeds fuel from a fuel tank 101. A low-pressure fuel pipe 103 connected to the discharge side of the feed pump 102 is directed toward the low-pressure fuel system LF and the high-pressure fuel system HF. Each branching.

  The low pressure fuel system LF is provided with a low pressure fuel system delivery pipe 104 connected to one branch side of the low pressure fuel pipe 103. The low pressure fuel delivery pipe 104 is connected to the port injectors 75R, 75R,... Of each cylinder (four cylinders), and suppresses fuel pressure pulsation in the low pressure fuel delivery pipe 104. A pulsation damper 105 is provided.

  On the other hand, the high pressure fuel system HF is pressurized by the fuel pumped out by the feed pump 102 and sucked through the other branch side of the low pressure fuel pipe 103, and the in-cylinder direct injection injector 78R of each cylinder (four cylinders). , 78R, a high pressure fuel pump 110 is provided.

  As a schematic configuration of the high-pressure fuel pump 110, a cylinder 111, a plunger 112, a pressurizing chamber 113, and an electromagnetic spill valve 114 are provided. The plunger 112 has a lifter 112a attached to its lower end. A drive cam 115 is integrally attached to the intake camshaft 35R. The drive cam 115 is formed with two cam peaks (cam noses) 116 and 116 at an angular interval of 180 ° around the rotation axis of the intake camshaft 35R. Thereby, the rotation of the drive cam 115 accompanying the rotation of the intake camshaft 35R causes the plunger 112 to be pushed up by the cam noses 116, 116 via the lifter 112a. The volume of the is increased or reduced.

  Since the engine E according to the present embodiment has four cylinders in one bank, the injector (the port injection injector 75R described above) provided for each cylinder during one cycle of the engine E, that is, while the crankshaft C rotates twice. And one or both of the in-cylinder direct injection injectors 78R). Further, in the engine E, the intake camshaft 35R rotates once every time the crankshaft C rotates twice. Therefore, the fuel injection from the injectors 75R and 78R is performed four times, and the discharge operation from the high-pressure fuel pump 110 is performed twice, every cycle of the engine E.

  The pressurizing chamber 113 is partitioned by a plunger 112 and a cylinder 111. The pressurizing chamber 113 communicates with the feed pump 102 via a low-pressure fuel pipe 103, and communicates with a high-pressure fuel delivery pipe (pressure accumulation container) 107 via a high-pressure fuel pipe 106.

  The in-cylinder direct injection injectors 78R, 78R,... Are connected to the high-pressure fuel delivery pipe 107, and a return pipe 108 is connected via a relief valve 107a. The relief valve 107a is opened when the fuel pressure in the high-pressure fuel system delivery pipe 107 exceeds a predetermined pressure (for example, 15 MPa). By opening the valve, a part of the fuel stored in the high-pressure fuel system delivery pipe 107 is returned to the fuel tank 101 via the return pipe 108. As a result, an excessive increase in fuel pressure in the high-pressure fuel delivery pipe 107 is prevented. The return pipe 108 and the high-pressure fuel pump 110 are connected by a fuel discharge pipe 109, and the fuel leaked from the gap between the plunger 112 and the cylinder 111 enters the fuel storage chamber 118 at the upper part of the seal unit 117. Then, the fuel is accumulated and then returned to the fuel tank 101 through the fuel discharge pipe 109 and the return pipe 108 connected to the fuel storage chamber 118.

  The low-pressure fuel pipe 103 is provided with a filter 103a and a pressure regulator 103b. The pressure regulator 103b returns the fuel in the low-pressure fuel pipe 103 to the fuel tank 101 when the fuel pressure in the low-pressure fuel pipe 103 exceeds a predetermined pressure (for example, 0.4 MPa). The fuel pressure is maintained below a predetermined pressure. Further, a pulsation damper 119 is provided on the suction side of the high-pressure fuel pump 110, and the pulsation damper 119 suppresses fuel pressure pulsation in the low-pressure fuel pipe 103 when the high-pressure fuel pump 110 is operated. It has become. The high-pressure fuel pipe 106 is provided with a check valve 120 for preventing the fuel discharged from the high-pressure fuel pump 110 from flowing backward.

  The high-pressure fuel pump 110 is provided with the electromagnetic spill valve 114 for communicating or blocking between the low-pressure fuel pipe 103 and the pressurizing chamber 113. The electromagnetic spill valve 114 includes an electromagnetic solenoid 114a, and opens and closes by controlling energization to the electromagnetic solenoid 114a. The electromagnetic spill valve 114 is opened by the biasing force of the coil spring 114b when energization to the electromagnetic solenoid 114a is stopped. Hereinafter, the opening / closing operation of the electromagnetic spill valve 114 will be described.

  First, when the energization of the electromagnetic solenoid 114a is stopped, the electromagnetic spill valve 114 is opened by the biasing force of the coil spring 114b, and the low pressure fuel pipe 103 and the pressurizing chamber 113 are in communication with each other. In this state, when the plunger 112 moves in the direction in which the volume of the pressurizing chamber 113 increases (intake stroke), the fuel sent from the feed pump 102 is sucked into the pressurizing chamber 113 through the low-pressure fuel pipe 103. Is done.

  On the other hand, when the plunger 112 moves in the direction in which the volume of the pressurizing chamber 113 contracts (pressurization stroke), the electromagnetic spill valve 114 closes against the urging force of the coil spring 114b by energizing the electromagnetic solenoid 114a. Then, the low-pressure fuel pipe 103 and the pressurizing chamber 113 are disconnected from each other, and the check valve 121 is opened when the fuel pressure in the pressurizing chamber 113 reaches a predetermined value. And is discharged toward the high-pressure fuel system delivery pipe 107.

  The fuel discharge amount in the high-pressure fuel pump 110 is adjusted by controlling the valve closing period of the electromagnetic spill valve 114 in the pressurization stroke. That is, if the closing time of the electromagnetic spill valve 114 is advanced and the closing period is lengthened, the fuel discharge amount increases. If the closing start time is delayed by delaying the closing time of the electromagnetic spill valve 114, the fuel discharge amount decreases. To come. In this way, the fuel pressure in the high-pressure fuel delivery pipe 107 is controlled by adjusting the fuel discharge amount of the high-pressure fuel pump 110.

  The above is the structure of the fuel supply system 100 provided in the right bank 2R, and the same fuel supply system 100 is provided in the left bank 2L.

-Support structure of high-pressure fuel pump 110-
Next, a support structure for the high-pressure fuel pump 110, which is a feature of the present embodiment, will be described. Here, the support structure of the high-pressure fuel pump 110 provided in the right bank 2R will be described as a representative.

  The high-pressure fuel pump 110 is supported by a pump support bracket 9 attached to the upper part of the camshaft housing 38R constituting the cylinder head 3R. Hereinafter, the configuration of the camshaft housing 38R and the pump support bracket 9 and the support structure of the high-pressure fuel pump 110 will be described.

<Configuration of camshaft housing 38R>
FIG. 4A is a plan view of the camshaft housing 38R in the right bank 2R (viewed from the direction along the cylinder axis of the right bank 2R), and the lower side in the figure is the engine front side (timing chain, auxiliary pulley, etc.) Is the side on which is disposed. Moreover, FIG.4 (b) is IV arrow line view in Fig.4 (a).

  As shown in these drawings, the camshaft housing 38R has an outer edge shape that substantially matches the outer edge shape of the cylinder head main body 37R, and includes a frame portion 200 that constitutes the outer frame of the camshaft housing 38R. Bolt holes 201, 201,... Are formed at a plurality of locations at predetermined intervals on the outer peripheral edge portion of the frame portion 200. By inserting head bolts into the bolt holes 201, the camshaft housing 38R. Are integrally fastened to the cylinder block 1 together with the cylinder head body 37R.

  The frame portion 200 includes a pair of first frames 202 and 202 extending in a direction (longitudinal direction of the frame portion 200) along the extending direction of the crankshaft C (vertical direction in FIG. 4A), and the crankshaft C A pair of second frames 203, 203 extending in a direction orthogonal to the extending direction (short direction of the frame portion 200) is provided, and the frames 202, 202, 203, 203 form a substantially rectangular shape in plan view. Has been.

  And the bearing parts 204-208 are formed in multiple places ranging over said pair of 1st frames 202,202. The bearing portions 204 to 208 are formed at a total of five locations: two locations that are both ends in the longitudinal direction of the camshaft housing 38R and three locations that are regions between the cylinders. Here, for convenience, the lower side (front side of the engine E) in FIG. 4 is the first cylinder, and the second cylinder, the third cylinder, and the fourth cylinder are arranged in order toward the upper side (rear side of the engine E). It is assumed that it is configured.

  The bearing portions 204 to 208 provided at the five locations will be described below. A first bearing portion 204 is formed in front of the engine E from the position of the first cylinder. The first bearing portion 204 is integrated with the second frame 203 located on the front end side of the engine E. A second bearing portion 205 is disposed between the position where the first cylinder is disposed and the position where the second cylinder is disposed, and the position where the second cylinder is disposed and the position where the third cylinder is disposed. The third bearing 206 is located between the third cylinder and the fourth cylinder, and the fourth bearing 207 is located between the third cylinder and the fourth cylinder. A fifth bearing 208 is formed on the rear side.

  The bearings 204 to 208 are provided with intake side bearing recesses 204a to 208a formed by semicircular recesses for rotatably supporting the lower side of the intake camshaft 35R and the lower side of the exhaust camshaft 36R. Exhaust-side bearing recesses 204b to 208b each formed of a similar semicircular arc-shaped recess for supporting each other are formed. Further, both sides of the intake side bearing recesses 204a to 206a (both sides in the extending direction of the respective bearing portions 204 to 206) and the exhaust side bearing recesses of the first bearing portion 204, the second bearing portion 205, and the third bearing portion 206, respectively. Bolt holes 204c to 206c for bolting cam caps 204f to 206f, which will be described later, are formed on both sides of 204b to 206b (both sides in the extending direction of the bearing portions 204 to 206).

  As one of the features of the present embodiment, on both sides of the exhaust-side bearing recesses 207b and 208b (both sides in the extending direction of the bearings 207 and 208) in the fourth bearing part 207 and the fifth bearing part 208, The bolt holes 207c and 208c for bolting the cam caps 207f and 208f are formed in the same manner as described above, whereas the intake-side bearing recesses (recesses forming the head-side bearing surface in the present invention) 207a and 208a Bolt holes 207d and 208d for bolting a pump support bracket 9, which will be described later, are formed on both sides (also both sides in the extending direction of the bearing portions 207 and 208).

  In each of the bearing portions 205 to 208, lubricating oil for lubricating between the bearing recesses 205 a to 208 a, 205 b to 208 b and the camshafts 35 R and 36 R is directed toward the inner surfaces of the bearing recesses 205 a to 208 a, 205 b to 208 b. Oil supply holes 205e to 208e for supplying are formed. That is, the lubricating oil discharged from the oil pump and supplied to the oil supply passage formed through the main gallery and over the inside of the cylinder head main body 37R and the inside of the camshaft housing 38R is received by the bearing recesses 205a to 208a and 205b to. It is the structure which supplies toward the inner surface of 208b.

  An oil reservoir (lubricant reservoir) 210 is integrally formed adjacent to the intake side bearing recess 207a in the fourth bearing 207. Specifically, the oil reservoir 210 is continuously formed on the side surface of the intake-side bearing recess 207a in the fourth bearing portion 207 (the side surface facing the fifth bearing portion 208), and accumulates lubricating oil. For this reason, a concave portion (curved concave portion) 210a formed by a curved surface and a wall plate 210b constituting a vertical wall of the concave portion 210a are provided. That is, an oil sump space that opens upward is formed by the side surface of the intake-side bearing recess 207a in the fourth bearing portion 207, the recess 210a, and the wall plate 210b. Thereby, when the engine E is driven, a part of the lubricating oil supplied to the intake side bearing recess 207a of the fourth bearing portion 207 flows into the oil reservoir portion 210 and is stored. More specifically, the camshaft housing 38R shown in FIG. 4 is disposed in the right bank 2R, and is inclined so that the left side in the drawing is the lower side. And the said wall board 210b is formed so that the left side may be enclosed from the upper side in a figure with respect to the recessed part 210a. For this reason, it is possible to accumulate oil in the concave portion 210a satisfactorily. The oil reservoir 210 may be integrally formed with the pump support bracket 9 described later.

  In a state where the intake camshaft 35R is rotatably supported by the camshaft housing 38R, a part of the drive cam 115 is located in an oil reservoir space that is an inner space of the oil reservoir portion 210. For this reason, in a situation where oil is stored in the oil reservoir portion 210, the outer peripheral surface of the drive cam 115 (sliding surface with respect to the lifter 112a of the high-pressure fuel pump 110) is always immersed in the oil. The effect of reducing friction between the outer peripheral surface of the cam 115 and the lifter 112a of the high-pressure fuel pump 110 can be obtained with certainty.

<Configuration of pump support bracket 9>
Next, the pump support bracket 9 that is a member that is attached to the camshaft housing 38R and supports the high-pressure fuel pump 110 will be described. 5 (a) is a plan view of the pump support bracket 9, FIG. 5 (b) is a front view of the pump support bracket 9, FIG. 6 (a) is a side view of the pump support bracket 9, and FIG. 6 (b) is a pump support. It is a bottom view of the bracket 9. FIG. 7 is an exploded perspective view of the camshaft housing 38R, the camshafts 35R and 36R, the pump support bracket 9, and cam caps 204f to 208f described later.

  As shown in these drawings, the pump support bracket 9 includes a bracket body 91 that is a portion on which the high-pressure fuel pump 110 is placed, and attachment legs 92 to 95 that are attachment portions to the camshaft housing 38R. ing.

  The bracket main body 91 has an opening 91a penetrating in the thickness direction on one side in the longitudinal direction (vertical direction in FIG. 5A). The opening 91a is formed at a position facing the drive cam 115 when the pump support bracket 9 is attached to the camshaft housing 38R. Further, the upper surface of the outer peripheral portion of the opening 91a is formed as a pump mounting surface 91b formed by a flat surface. Bolt holes 91c and 91c are formed at two locations on the pump mounting surface 91b (two locations on the longitudinal direction side of the bracket body 91), and mounting flanges (flange portions) 110a (see FIG. 13) is mounted on the pump mounting surface 91b via a spacer 110b and an insulator 110c (see FIG. 15), which will be described later, and a bolt hole formed in the mounting flange 110a and a bolt hole in the pump mounting surface 91b. The high-pressure fuel pump 110 is mounted on the pump support bracket 9 by inserting the mounting bolts B1 and B1 in the state where the positions 91c and 91c are aligned with each other (details of the mounting structure). Will be described later). At this time, the lifter 112a of the high-pressure fuel pump 110 is inserted into the opening 91a, and the outer peripheral surface of the drive cam 115 of the intake camshaft 35R located below the opening 91a is the lower surface of the lifter 112a. It comes to contact with.

  Further, the upper surface of the intake camshaft 35R is placed on the lower surface of the bracket main body 91 and on the portion facing the intake side bearing recess 207a of the fourth bearing portion 207 and the intake side bearing recess 208a of the fifth bearing portion 208. Bearing recesses 91d and 91e (recesses forming the bracket side bearing surface referred to in the present invention) 91d and 91e, which are semicircular arc recesses for rotatably supporting, are formed (see FIG. 6B). That is, in a state where the pump support bracket 9 is disposed so as to straddle the fourth bearing portion 207 to the fifth bearing portion 208, the pump support bracket 9 rotatably supports the upper side of the intake camshaft 35R. Thus, the pump support bracket 9 is configured to function as a cam cap. For this reason, since the cam cap is not required in the portion where the pump support bracket 9 is disposed, it is possible to reduce the number of parts and reduce the size of the engine E by effectively using the space.

  On the other hand, as the mounting leg portions 92 to 95 of the pump support bracket 9, a total of four extending from both ends in the longitudinal direction of the bracket main body portion 91 are formed. The distance between the mounting legs 92 and 93 formed on one side in the longitudinal direction of the bracket body 91 and the mounting legs 94 and 95 formed on the other side (the dimension t1 in FIG. 5A). ) Substantially coincides with the distance between the fourth bearing portion 207 and the fifth bearing portion 208 (dimension T1 in FIG. 4A) of the camshaft housing 38R. Further, bolt holes 92a to 95a are formed at positions in the vicinity of the tips of the mounting legs 92 to 95, respectively. When the pump support bracket 9 is attached to the camshaft housing 38R, the distance between the bolt holes 92a and 93a in the attachment legs 92 and 93 facing the fourth bearing portion 207 is the fourth bearing portion 207. Is substantially the same as the distance between the bolt holes 207d and 207d formed on both sides of the intake-side bearing recess 207a. Similarly, in the state where the pump support bracket 9 is attached to the camshaft housing 38R, the distance between the bolt holes 94a and 95a in the attachment legs 94 and 95 facing the fifth bearing 208 is the fifth bearing 208. Is substantially the same as the distance between the bolt holes 208d and 208d formed on both sides of the intake-side bearing recess 208a. Therefore, when the pump support bracket 9 is disposed so as to extend from the fourth bearing portion 207 to the fifth bearing portion 208, the bolt holes 92a formed in the mounting leg portions 92 to 95 of the pump support bracket 9 are provided. To 95a are opposed to the bolt holes 207d, 207d, 208d, and 208d in the fourth bearing portion 207 and the fifth bearing portion 208, respectively, and span these bolt holes 92a to 95a, 207d, 207d, 208d, and 208d. The pump support bracket 9 is attached to the camshaft housing 38R by inserting the bolts B2, B2,... (See FIG. 11).

  One of the features of the pump support bracket 9 is that an oil passage 96 and an oil jet 97 (oil supply passage in the present invention) for injecting oil are formed on the lower surface of the lifter 112a of the high-pressure fuel pump 110. Can be mentioned. Hereinafter, the oil passage 96 and the oil jet 97 will be described.

  8 is a cross-sectional view taken along line VIII-VIII in FIG. 5A, FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 5A, and FIG. FIG.

  As shown in these drawings, an oil passage 96 formed of a recessed portion is formed from the lower surface of the pump support bracket 9 facing the fourth bearing portion 207 of the camshaft housing 38R to the inner peripheral surface of the bearing recess 91d. . An oil jet 97 having one end communicating with the oil passage 96 and the other end opened toward the opening 91a is formed through the bracket body 91. Therefore, the oil flowing into the oil passage 96 is ejected from the oil jet 97 in the direction toward the opening 91a. As described above, the lifter 112a of the high-pressure fuel pump 110 is inserted into the opening 91a, and the lifter 112a is in sliding contact with the drive cam 115 of the intake camshaft 35R located below the opening 91a. Therefore, the oil from the oil jet 97 is sprayed on the lower surface of the lifter 112a (see the arrow in FIG. 10), so that the lubricity between the lifter 112a and the drive cam 115 can be obtained satisfactorily. It has become. Thereby, mechanical loss can be reduced and the high-pressure fuel pump 110 can be driven with high efficiency.

  In FIG. 11A, the camshaft housing 38R is attached to the upper surface of the cylinder head main body 37R, and the pump support bracket 9 is disposed so as to straddle the fourth bearing portion 207 to the fifth bearing portion 208 of the camshaft housing 38R. It is a top view which shows the state which installed and integrated these. FIG. 11B is a front view thereof, and FIG. 12 is a side view thereof. In these drawings, cam caps 204f to 208f are attached to the bearings 204 to 208, respectively.

  In this manner, in the state where the camshaft housing 38R, the pump support bracket 9, and the cam caps 204f to 208f are integrally assembled on the upper surface of the cylinder head main body 37R, the bolt indicated by B2 in FIG. The pump support bracket 9, the camshaft housing 38R, and the cylinder head body 37R are inserted and fastened together. Further, a bolt denoted by reference numeral B3 in the figure is inserted through the cam caps 204f to 208f, the camshaft housing 38R, and the cylinder head main body 37R to integrally fasten them. Further, a bolt indicated by reference numeral B4 in the drawing is inserted through the cam caps 204f to 208f and the camshaft housing 38R to integrally fasten them. Further, a bolt indicated by reference numeral B5 in the drawing is inserted through the camshaft housing 38R and the cylinder head main body 37R to integrally fasten them.

  FIG. 13 is a plan view showing a state where the high pressure fuel pump 110 is attached to the pump support bracket 9 assembled to the camshaft housing 38R, and FIG. 14 is a side view thereof. Further, FIG. 15 is an exploded perspective view of the head cover 4R, the high-pressure fuel pump 110, the spacer 110b, and the insulator 110c.

  As shown in these figures, the mounting flange 110a of the high-pressure fuel pump 110 is placed on the pump mounting surface 91b via the insulator 110c and the spacer 110b, and bolt holes 110d and 110d formed in the mounting flange 110a are With the bolt holes 91c and 91c of the pump mounting surface 91b of the pump support bracket 9 aligned, the mounting bolts (stud bolts) B1, which have been previously mounted on the bolt holes 91c and 91c of the pump mounting surface 91b, are installed. B1 is inserted into bolt holes 110d and 110d formed in the mounting flange 110a, and nuts N1 and N1 are mounted from above, whereby the high-pressure fuel pump 110 is mounted on the pump support bracket 9. The spacer 110b and the insulator 110c are also formed with openings for inserting the mounting bolts B1 and B1.

  In this case, the portion of the high-pressure fuel pump 110 above the mounting flange 110a is disposed so as to protrude from the head cover 4R (see the phantom line in FIG. 14). One of the features of this embodiment is the shape of the seal member 220 provided for sealing the internal space (cam chamber 41R) of the head cover 4R. FIG. 16 is a cross-sectional view of the periphery of the mounting position of the seal member 220.

  As shown in FIG. 16, the seal member 220 is a ring-shaped member made of rubber and fitted into an opening 221 as a fuel pump installation space formed in the head cover 4R, and the seal member 220 is formed of the opening 221 of the head cover 4R. A vibration-absorbing lip portion 220a that contacts the lower surface of the spacer 110b is formed in a state of being fitted between the edge portion and the spacer 110b disposed below the high-pressure fuel pump 110. That is, the vibration of the high-pressure fuel pump 110 is absorbed by the lip portion 220a of the seal member 220 and transmitted to the head cover 4R while suppressing the sealing function that the cam chamber 41R does not communicate with the outside. become. As a result, it is possible to prevent the generation of abnormal noise (large vibration noise caused by the vibration of the high-pressure fuel pump 110 being transmitted to the head cover 4R and functioning as a speaker) due to the vibration of the head cover 4R. Yes.

  As described above, in the present embodiment, the high-pressure fuel pump 110 is supported by the pump support bracket 9 disposed across the plurality of bearing portions 207 and 208 of the camshaft housing 38R. For this reason, the support rigidity with respect to the high-pressure fuel pump 110 can be obtained sufficiently high, and the vibration generated when the high-pressure fuel pump 110 is driven can be sufficiently absorbed, and this vibration is transmitted to other members. Can be prevented.

-Other embodiments-
In the embodiment described above, the case where the fuel pump support structure according to the present invention is applied to a V-type 8-cylinder engine for automobiles has been described. The present invention is not limited to this, and can also be applied to an in-line engine for automobiles, a horizontally opposed engine for automobiles, and the like. Further, the present invention is not limited to automobiles but can be applied to other engines. Further, the number of cylinders, the angle between the V banks in the V-type engine E, and other specifications of the engine E are not particularly limited.

  In the above-described embodiment, the case where the pump support bracket 9 is disposed so as to extend from the fourth bearing portion 207 to the fifth bearing portion 208 of the camshaft housing 38R has been described. The present invention is not limited to this, and may be configured so as to straddle other receiving portions 204 to 206. Moreover, you may arrange | position the pump support bracket 9 so that three or more bearing parts 204-208 may be straddled. Furthermore, the bearing portions 204 to 208 to which the pump support bracket 9 is attached do not necessarily have to be adjacent bearing portions. For example, the bearing portions 204 to 208 straddle the third bearing portion 206 and the fifth bearing portion 208 in the above embodiment. In this manner, the pump support bracket 9 may be disposed.

  In the above embodiment, the cylinder heads 3L and 3R are divided and the high pressure fuel pump 110 is supported on the camshaft housings 38L and 38R via the pump support bracket 9, but the cylinder heads 3L and 3R are supported. The high pressure fuel pump 110 may be supported on the cylinder heads 3L and 3R via the pump support bracket 9 without using a split structure.

It is a figure which shows schematic structure inside the engine which looked at the V-type engine which concerns on embodiment from the direction along the axial center of a crankshaft. It is a system configuration diagram showing an outline of an engine and intake and exhaust systems. It is a figure which shows typically the structure of a fuel supply system. 4 (a) is a plan view of the camshaft housing, and FIG. 4 (b) is a view taken along the arrow IV in FIG. 4 (a). FIG. 5A is a plan view of the pump support bracket, and FIG. 5B is a front view of the pump support bracket. 6A is a side view of the pump support bracket, and FIG. 6B is a bottom view of the pump support bracket. It is a disassembled perspective view of a camshaft housing, each camshaft, a pump support bracket, and a cam cap. It is sectional drawing along the VIII-VIII line in Fig.5 (a). FIG. 6 is a cross-sectional view taken along line IX-IX in FIG. It is a figure which expands and shows the X part in FIG. FIG. 5 is a view corresponding to FIG. 4 showing a state where a pump support bracket and a cam cap are assembled to the camshaft housing. It is a side view which shows the state by which the pump support bracket and the cam cap were assembled | attached to the cam shaft housing. It is a top view which shows the state by which the camshaft housing, the pump support bracket, and the high pressure fuel pump were assembled | attached integrally. It is a side view which shows the state in which the camshaft housing, the pump support bracket, and the high-pressure fuel pump were assembled together. It is a disassembled perspective view of a head cover, a high-pressure fuel pump, a spacer, and an insulator. It is sectional drawing of the arrangement position periphery of a sealing member.

Explanation of symbols

3L, 3R Cylinder head 35L, 35R Intake camshaft 4L, 4R Cylinder head cover 78L, 78R In-cylinder direct injection injector (fuel injection valve)
9 Pump support brackets 91d, 91e Bearing recess 96 Oil passage 97 Oil jet 110 High-pressure fuel pump 110a Mounting flange (flange)
111 Cylinder 112 Plunger 112a Lifter 113 Pressurizing chamber 115 Driving cam 207, 208 Bearing portion 207a, 208a Intake side bearing recess 210 Oil reservoir portion (lubricating oil reservoir portion)
220 Seal member 220a Lip part 221 Opening part E Engine (internal combustion engine)

Claims (6)

In a fuel pump support structure of an internal combustion engine for supporting a fuel pump for boosting fuel supplied toward a fuel injection valve on a cylinder head,
The cylinder head is provided with a plurality of bearing portions in the cylinder row direction for rotatably supporting the camshaft,
It has a pump support bracket which is arranged straddling at least two bearing portions among the plurality of bearing portions and is fixedly supported by these bearing portions, and a fuel pump is attached to the pump support bracket. A fuel pump support structure for an internal combustion engine. In the fuel pump support structure of the internal combustion engine according to claim 1,
In the pump support bracket, a similar bracket side bearing surface is formed at a portion facing the head side bearing surface which becomes the bearing surface of the camshaft in the bearing portion of the cylinder head, and the camshaft can be rotated together with the head side bearing surface. A structure for supporting a fuel pump of an internal combustion engine, wherein In the fuel pump support structure for an internal combustion engine according to claim 1 or 2,
A fuel pump is inserted into a cylinder so as to be reciprocally movable, and a plunger that defines a pressurizing chamber and a pressing force from a driving cam integrally formed on a camshaft are applied to the plunger to reduce the pressurizing chamber And a lifter that moves the plunger in the direction to
2. A fuel pump support structure for an internal combustion engine, wherein an oil supply passage for supplying lubricating oil is formed in the pump support bracket toward a sliding contact portion between the lifter and the drive cam. In the fuel pump support structure for an internal combustion engine according to claim 1 or 2,
The fuel pump is driven by receiving a pressing force from a drive cam formed integrally with the camshaft,
One of the cylinder head and the pump support bracket is integrally formed with a lubricating oil storage portion for storing the lubricating oil supplied to the bearing portion at a position facing the outer peripheral surface of the drive cam. A fuel pump support structure for an internal combustion engine. In the fuel pump support structure for an internal combustion engine according to any one of claims 1 to 4,
On the upper side of the cylinder head, a cylinder head cover in which an opening as a fuel pump installation space is formed is attached,
An annular seal member for sealing the inner space of the cylinder head cover is disposed at the edge of the opening of the cylinder head cover and is disposed around the entire circumference. A structure for supporting a fuel pump of an internal combustion engine, wherein a vibration absorbing lip portion for preventing generated vibration from being transmitted to a cylinder head cover is formed.   6. The fuel pump support structure for an internal combustion engine according to claim 1, wherein the bearing is disposed across at least two bearing portions of the plurality of bearing portions of the cylinder head and these bearings. A pump support bracket characterized by being configured to support the fuel pump in a state of being fixedly supported by the portion.

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