JP2016006314A - Cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injector in a form in which the injector can be exactly and easily attached, in a cylinder head in which two suction ports are arranged while responding to one cylinder, and the injectors are attached to both the suction ports.SOLUTION: A plurality of paired injector attachment holes 40 are formed at one side face of a cylinder head 2 in parallel with one another. An injector unit 43 is attached in a state that a plurality of paired injectors 36 are branched to a delivery pipe 42. A cover attachment rib 55 for fixing a head cover with a bolt is formed at an upper part of an intermediate part of the paired injector attachment holes 40 in a vertically-long state. When attaching the injector unit 43, since each injector 36 can be inserted into the injector attachment hole 40 with the cover attachment rib 55 as a mark, the insertion of the injector 36 can be exactly and easily performed.

Description

  The present invention relates to a cylinder head constituting an internal combustion engine for a vehicle or the like.

  In general, an internal combustion engine for a vehicle is provided with two intake valves and two exhaust valves for one cylinder. Further, in recent internal combustion engines, most of the fuel is injected into the intake port by an injector. In this case, there is a single type that supplies fuel from one injector to one cylinder, and a dual type that supplies fuel from two injectors to one cylinder. The advantage of the dual type is that precise and fine control can be performed. There is.

  In any case, a plurality of injectors are connected to a single delivery pipe (fuel distribution pipe), and a plurality of injectors and a single delivery pipe constitute an injector unit, and each injector is connected to a cylinder head. The brackets provided on the delivery pipe are fixed to the cylinder head with bolts after being simultaneously inserted into the injector mounting holes (for example, Patent Document 1).

JP 2009-191636 A

  Although the tip of the injector is a nozzle that injects fuel, the nozzle has a thin and delicate structure. When assembling, attach the injector while carefully positioning it so that it does not hit the cylinder head. This had to be inserted into the hole, and it took time and labor to assemble the injector unit. In particular, in the case of having two injectors corresponding to one cylinder, the nozzle is more likely to come into contact with the head as compared with the single type.

  The present invention has been made in view of such a current situation, and intends to reduce the labor of assembling an injector without complicating the structure.

The present invention relates to an improvement of a cylinder head, and this cylinder head has a structure in which an intake port and an injector mounting hole are opened on one side surface and a head cover is fixed to the upper surface with a bolt as claimed in claim 1. Because
The intake port and the injector mounting hole are a pair corresponding to one cylinder, and the pair of the intake port and the injector mounting hole are arranged in the crank axis direction with the injector mounting hole positioned above. Further, a cover mounting rib for fixing the head cover is formed in a portion of the one side surface directly above an intermediate portion of the pair of injector mounting holes.

  The present invention also includes the structure of claim 2. According to a second aspect of the present invention, in the first aspect, the pair of intake ports are divided by a partition, and the partition is located below the cover mounting rib.

  In the present invention, since the cover mounting rib is positioned above the pair of injector mounting holes, when assembling the injector unit to the cylinder head, the cover mounting rib is used as a positioning guide (marker / index). By arranging the injectors so as to be located on both sides of the cover mounting rib, each injector can be accurately inserted into each injector mounting hole.

  Furthermore, although the injector mounting hole can also be used as a mark, it is difficult for humans to see if the center of the injector is aligned with the center of the injector mounting hole. For this reason, the nozzle may hit the inner surface of the injector mounting hole and be damaged, but the cover mounting rib protrudes from the outer surface of the cylinder head and has high visibility. By defining the position of the injector unit so that it is located between the injectors, it is possible to insert each injector concentrically into each injector mounting hole. As a result, the assembly of the injector unit can be performed accurately and efficiently. Can do well.

  Since the cover mounting rib is used as a mark, there is no increase in cost or weight. Therefore, the injector can be mounted accurately and efficiently without incurring a cost increase.

  Now, when two injectors are provided corresponding to one cylinder, it is possible to branch only the portion facing the tip of the injector into two intake ports. Therefore, the two intake ports can be divided into cover mounting ribs. In this case, when the partition is fixed with bolts, the intake port is deformed by pulling the meat above the intake port with bolts. There is a fear.

  On the other hand, if the configuration of claim 2 is adopted, the upper and lower surfaces of the intake port are connected by the partition wall, and therefore, there is an advantage that deformation of the intake port can be prevented even if an upward pull is applied by a bolt for fixing the head cover. is there.

1 is a partial schematic front view of an internal combustion engine according to an embodiment. It is a perspective view of a cylinder head. It is a perspective view of a surge tank integrated intake manifold (parallel oblique lines are display of a surface, not a cross-sectional display). It is a rear view of an intake manifold. FIG. 7 is a plan sectional view of the intake port, and is a sectional view taken along line VV in FIG. FIG. 10 is a longitudinal front view of a portion of one intake port, and is a cross-sectional view taken along line VI-VI in FIG. 9 with an injector attached. (A) is the elements on larger scale of FIG. 9 in the state which displayed the intake manifold, (B) is BB sectional drawing of (A). It is a separation top view of a cylinder head and a head cover. It is a separation top view of a cylinder head and an injector unit. (A) is the isolation | separation perspective view of an injector unit, (B) is the isolation | separation front view of an injector unit.

(1). Outline of Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline of an internal combustion engine will be described mainly with reference to FIGS. The present invention is applied to an internal combustion engine for a vehicle. As shown in FIG. 1, the internal combustion engine includes a cylinder block 1 and a cylinder head 2 fixed to the upper surface thereof as in the prior art. A head cover 3 is fixed to the upper surface of 2. A front cover that covers the timing chain is disposed on one end face of the cylinder head 2 and the cylinder block 1, but is omitted in the drawing.

  The internal combustion engine of the present embodiment is disposed in the engine room of the vehicle in a posture in which a crankshaft (not shown) is horizontally oriented when viewed from the driver. Further, the cylinder axis 4 is directed in the direction of the vertical line 5 (may be slanted forwardly or the like). Accordingly, the vertical direction coincides with the direction of the cylinder axis 5. The front-rear direction is defined as the direction viewed from the driver of the vehicle. The front view is a state seen from the crank axis direction. As described above, the left-right direction is the same as the crank axis direction.

  The cylinder head 2 is a substantially rectangular shape that is horizontally long, and the lower half of the rear surface 2a is inclined so as to shift backward as it goes downward. The flange 6a of the intake manifold 6 is provided on the inclined rear surface 2a. It is fixed with bolts. Further, the internal combustion engine of the present embodiment has three cylinders. Therefore, as shown in FIG. 2, the cylinder head 2 is formed with three spark plug insertion holes 7 arranged in the direction of the crank axis 7. The cylinder head 2 is a cast aluminum product, and the intake manifold 6 is a resin molded product made of nylon resin or the like.

  Around the cylinder head 2, a front and rear long side wall portion 9 and left and right short side wall portions 10 are formed in a continuous state, and one short side wall portion 10 has a cam shaft 11 ( Side bearings 12 are formed to support (see FIG. 9) from below. In addition, intermediate bearings 13 that support the camshaft 11 from below are also formed in the inside of the cylinder head 2 at both the front and rear sides sandwiching each spark plug insertion hole 7. Needless to say, a cam cap 14 (see FIG. 9) covering the cam shaft 11 from above is fixed to the bearings 12 and 13 with bolts.

  In addition, the code | symbol 15 shown in FIG. 2 is an EGR gas extraction opening. Reference numeral 16 indicates an opening of the cooling water passage.

  The intake manifold 6 is shown in FIGS. The intake manifold 6 of this embodiment is integrally provided with a surge tank 17, and an intake inlet 18 is open in the surge tank 17 as shown in FIG. As shown in FIG. 1, a throttle valve 19 is connected to the intake inlet 18.

  The intake manifold 6 is made of resin and is formed by joining upper and lower parts. And since it is 3 cylinders, it has the three branch pipes 20 arranged in the left-right direction, but each branch pipe 20 changes the direction once upward from the front end part of the surge tank 17, and is directed forward. Therefore, it is bent like a horn of a musical instrument. The upper half of each branch pipe 20 partially enters the surge tank 17.

  As shown in FIG. 3B, a land portion 21 extending in the direction in which the branch pipes 20 are arranged (left-right direction) is formed on the upper surface of the rear portion of the intake manifold 6, and a lid plate 22 is welded to the land portion 21. doing. An EGR passage (not shown) is formed on the mating surface between the land portion 21 and the cover plate 22, and the EGR passage communicates with each branch pipe 20 via the branch passage.

  A flange 23 is provided at one end of the land portion 21, and an end of an EGR pipe (not shown) is fixed to the flange 23. Therefore, the EGR passage is open to the outer surface of the flange 23, and the start end of the EGR pipe is connected to the EGR gas outlet 15 shown in FIG.

(2). Intake path of intake port and intake manifold Next, the intake port and the intake path of the intake manifold 6 will be described with reference to FIGS. Although the internal combustion engine of the present embodiment has three cylinders, since two intake valves 26 are arranged corresponding to one cylinder 25 (see FIG. 6), the cylinder head 2 corresponds to one cylinder 25. Thus, two sets of intake ports 27 are formed, and three sets of intake ports 27 are formed. In FIG. 6, the cam is omitted. Although explanation is omitted, two exhaust valves are also provided in one cylinder 25.

  As shown in FIG. 5, the two intake ports 27 constituting each set are separated by a partition wall 28, but the front end (end portion facing the intake manifold 6) of the partition wall 28 is from the rear surface 2 a of the cylinder head 2. Is getting a little behind. That is, the front end of the partition wall 28 does not reach the rear surface 2 a of the cylinder head 2.

  On the other hand, as can be understood from FIGS. 3 and 4, the end portions of the branch pipes 20 in the intake manifold 6 are divided into left and right by the partition walls 29, respectively. The intake passage 30 is separated into a passage 30, and one intake passage 30 communicates with one intake port 27.

  The partition wall 29 of the intake manifold 6 is flush with the rear surface of the flange 6a (the overlapping surface with the cylinder head 2). Accordingly, a gap 32 is provided between the partition wall 28 of the cylinder head 2 and the partition wall 29 of the intake manifold 6.

  In this case, the front surface of the partition wall 28 in the cylinder head 2 has a concave lateral V shape (character shape) toward the intake manifold 6. Therefore, the front surface of the partition wall 28 is composed of a lower inclined surface 33 that shifts from the bottom toward the back side of the intake port 27 and an upper inclined surface 34 that shifts from the top to the bottom toward the back side of the intake port 27. The crossing portion (the bottom bottom portion of the front surface) of the vertically inclined surfaces 33 and 34 is located at the vertically middle portion of the intake port 27.

  Further, the partition wall 28 of the cylinder head 2 has the thinnest middle part at the top and bottom, and the thickness increases toward the top and bottom. Therefore, the portion of the intake port 27 whose inner surface is constituted by the partition wall 28 has an arc shape. In addition, the two intake ports 27 form an oval shape as a whole. Therefore, each intake port 27 has a substantially circular cross section. As shown in FIGS. 5 and 7B, the front end surface of the partition wall 28 of the cylinder head 2 has a rounded cross-sectional shape in a plan view in which the two intake ports 27 can be seen in parallel. ing. That is, the front end portion of the partition wall 28 has an arcuate cross-sectional shape.

  On the other hand, the two intake passages 30 forming one set in the intake manifold 6 have an oval shape as a whole, and the outer shape of the one set of intake ports 27 and the one set of intake passages 30 is the same shape as a whole. It has become. However, the partition wall 29 of the intake manifold 6 has an equal thickness over the entire length, and the thickness of the partition wall 29 of the intake manifold 6 is greater than the partition wall 28 of the cylinder head 2 as clearly shown in FIG. Is also thinner. Further, the rear end of the wall 29 of the intake manifold 6 is angular in a plan view (having a slight roundness).

  As described above, EGR gas is supplied to each branch pipe 20 from the land portion 21 of the intake manifold 6. The partition wall 29 of the intake manifold 6 is provided on the downstream side of the EGR gas supply port.

  As shown in FIG. 6, the intake port 27 extends in a substantially straight posture while being inclined in a front view so as to be shifted downward toward the tip. For this reason, intake air flows straight into the cylinder. As a result, a strong tumble dragon can be formed. Further, by tilting the front portion 2 a of the cylinder head 2, an overhang portion that protrudes behind one side surface of the cylinder block 1 is formed at the front end of the cylinder head 2.

(3). Injector and Head Cover As shown in FIGS. 6 and 7A, an injector 36 for fuel injection is attached to each intake port 27. The injector 36 and the head cover 3 will be described with reference to FIGS. 8 to 10 in addition to the previous drawings.

  The injector 36 includes a cylindrical body 37, and a small-diameter nozzle 39 is provided at the tip of the body 37 via an intermediate diameter portion 38. A portion of the rear surface of the cylinder head 2 above the inclined surface has an injector mounting hole 40 into which approximately half of the body 37 is loosely fitted, and an intermediate diameter portion 38 is formed at the back of the injector mounting hole 40. Is provided with a seal hole 41 into which the is fitted.

  Then, an O-ring (not shown) is attached to the intermediate diameter portion 38 of the injector 36, and the O-ring is fitted into the seal hole 41, thereby positioning and sealing the distal end portion of the injector 36. Since the injectors 36 are disposed in the respective intake ports 27, as shown in FIG. 2, two injector mounting holes 40 are formed as a set corresponding to the set of the two intake ports 27.

  As shown in FIG. 10, each injector 36 is attached to a delivery pipe (fuel distribution pipe) 42 that is long in the crank axis direction. Accordingly, the injector unit 43 is configured by one delivery pipe 42 and six injectors 36. After the injector unit 43 is formed in advance, the entire injector unit 43 is set in the cylinder head 2.

  A small diameter introduction pipe 44 is opened at the rear end of the body 37 in the injector 36, while the delivery pipe 42 is provided with a socket 45 in which the rear end portion of the body 37 of each injector 36 is fitted in parallel. The body 37 of the injector 36 is held in a socket 45 so as not to be detached by a clip (holder) 46 shown in FIG. 8B. A control unit 47 with a built-in valve branches off in the body 37 of each injector 36, and an appropriate amount of fuel is injected into the intake port 27 by driving the control unit 47 by a signal from the ECU.

  The left and right brackets 48 are fixed to the delivery pipe 42, and the brackets 48 are fixed to the upper surface of one long side wall portion 9 of the cylinder head 2 with bolts 50 via spacers 49. Therefore, two injector tap holes 51 into which the bolts 50 are screwed are formed on the upper surface of one long side wall portion 9 in the cylinder head 2.

  Of the two injector tap holes 51, the one located at the end of the cylinder head 2 is formed with a first forward rib 52 that protrudes rearward from one long side wall 9 of the cylinder head. The other injector tap hole 51 is formed at a location of a second forward rib 53 protruding slightly rearward from one long side wall portion 9.

  On the other hand, as shown in FIG. 8, the head cover 3 has a flange 54 that overlaps the upper surfaces of the three wall portions 9 and 10 in the cylinder head 2, while the wall portions 9 and 10 in the cylinder head 2 face outward. The cover mounting rib 55 is provided with the cover mounting rib 55 with a cover tapped hole 56, and the outward projecting portion 54 a provided on the flange 54 of the head cover 3 is formed on the cover mounting rib 55. It is fixed with bolts 57 (see FIG. 1).

  In the example shown in the figure, the head cover 3 is provided with the flange 54 on the entire periphery, but the flange may be provided only at the cover tap hole 56 of the cylinder head 2 and fixed with the bolt 57. .

  Then, as clearly shown in FIG. 9, the three cover mounting ribs 55 in one long side wall portion 9 are located directly above the intermediate portion between the two paired injector mounting holes 40. Yes. In addition, since the injector mounting hole 40 is located directly above the intake port 27, the partition wall 28 that separates the pair of intake ports 27 is positioned directly below the cover mounting rib 55 (the cover mounting rib 55 is It is located directly above the partition wall 28).

  In assembling the injector unit 43, the injector unit 43 is set in advance, and the respective injectors 36 are simultaneously fitted into the injector mounting holes 40, and then the bracket 48 is fixed to the cylinder head 2. In the embodiment, since the cover mounting rib 55 is located between the intake ports 27 constituting the left and right sets, each injector 36 can be easily and accurately fitted into the mounting hole 49 using the cover mounting rib 55 as a mark. it can. For this reason, the injector unit 43 can be easily and accurately attached.

  That is, since the cover mounting ribs 55 are exposed to the outside and have high visibility, the pair of injectors 36 are positioned so as to be positioned on the left and right sides of the cover mounting ribs 55 using the cover mounting ribs 55 as marks. By doing so, each injector 36 can be inserted concentrically with respect to the injector mounting hole 40, whereby the injector unit 43 can be attached to the cylinder head 2 while preventing problems such as damage to the nozzle 39. It can be done.

  Further, since the partition wall 28 of the cylinder head 2 is positioned directly below the cover mounting rib 55 and the rigidity of the portion around the intake port 27 is remarkably high, the pulling force by the bolt 57 is applied to the intake port 27. Even if it acts up to the upper surface, the upper surface of the intake port 27 is not pulled and deformed upward.

  The present invention can be embodied in an actual internal combustion engine. Therefore, it can be used industrially.

2 Cylinder head 2a Front side of cylinder head (one side)
3 Head Cover 6 Intake Manifold 7 Crank Axis 9, 10 Cylinder Head Wall 25 Cylinder 26 Intake Valve 27 Intake Port 28 Bulkhead Partitioning Intake Port 36 Injector 37 Injector Body 39 Injector Nozzle 40 Injector Mounting Hole 42 Delivery Pipe (Delivery Port) Plumbing)
43 Injector unit 54 Head cover flange 54 Flange outward projection 55 Cover mounting rib

Claims (2)

An intake port and an injector mounting hole are opened on one side surface, and the head cover is fixed to the upper surface with a bolt,
The intake port and the injector mounting hole are two pairs corresponding to one cylinder, and the pair of the intake port and the injector mounting hole are aligned in the crank axis direction with the injector mounting hole positioned above. Has been placed,
Further, a cover mounting rib for fixing the head cover is formed in a portion of the one side surface directly above the middle portion of the pair of injector mounting holes.
cylinder head. The pair of intake ports are divided by a partition wall, and the partition wall is located below the cover mounting rib.
The cylinder head according to claim 1.

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