JP3955279B2 - Fuel injection valve fixing structure - Google Patents

Description

  The present invention relates to a fuel injection valve fixing structure applicable to a direct injection engine.

  In a structure for fixing a direct injection injector as a fuel injection valve in a direct injection engine that directly injects fuel into a combustion chamber, an upper protrusion of the direct injection injector with the nozzle side immersed in the cylinder head is formed by a Y-shaped clamp member. Some are fixed so as to be pressed by a V-shaped engaging portion (for example, see Patent Document 1). In fixing using such a Y-shaped clamp member, the extended end of the handle extending from the V-shaped engaging portion is used as a pivot, and the intermediate portion of the handle is fixed to the cylinder head by a fixing bolt. (Or a member integrated with the cylinder head).

Japanese Patent Laid-Open No. 10-213051 (page 3-4, FIG. 1)

  In the above-mentioned Patent Document 1, since the Y-shaped clamp members are parallel to the camshaft and are all oriented in the same direction, a fixing bolt for pressing an intermediate portion of the handle portion to fix the Y-shaped clamp member to the cylinder head. Fastening work points are separated from each other. Therefore, not only the moving distance for moving from one fastening part to the next fastening part becomes long, but also when the fuel supply pipe extends from the opposite side of the Y-shaped clamping member, the clamping member is in the extending direction. Therefore, the fuel supply pipe interferes with the fastening operation for the fixing bolt. Therefore, the fastening operation of the fixing bolt becomes complicated, and there is a problem that the workability of assembling the Y-shaped clamp member is poor.

In order to solve such a problem and realize a fuel injection valve fixing structure that is easy to assemble and has a good load balance, in the present invention, each combustion chamber (3) of a multi-cylinder engine is directly above. A fuel injection valve fixing structure for fixing each direct injection injector (2) disposed to a cylinder head (1) by a clamp member (7), and a fuel distribution pipe ( 13), and each of the direct injection injectors (2) is connected from the fuel distribution pipe (13) via the same number of fuel supply pipes (12) as the direct injection injectors (2), and the clamp member (7) is a V-shaped engagement portion (7a) that engages with the direct injection injector (2), and a V-shaped engagement portion (7a) from a branch portion of the V-shaped engagement portion (7a). ) And in the opposite direction to the cylinder With a handle portion fixed to de (1) and (7b), in order from one end to the other end of the cylinder row direction, the handle portion (7b) between the clamp member adjacent (7) the counter In addition, one of the handle portions (7b) facing each other is inclined with respect to the line in the cylinder row direction at an angle that does not interfere with the other .

  In particular, the handle portion (7b) of the clamp member (7) and the fuel supply pipe (12) are preferably arranged so as to extend to opposite sides.

  As described above, according to the present invention, since the handle portions of the clamp members are arranged so as to be alternately arranged adjacent to each other, the direct injection injector is pressed by the V-shaped engagement portion of the Y-shaped clamp member. When the extension end of the handle is brought into contact with the cylinder head and the fixing bolt inserted through the intermediate portion of the handle is fastened to the cylinder head to fix the direct injection injector, Since the fastening work locations for the respective fixing bolts are close, the workability when moving from one fastening site to the other fastening site is good, and the assembly workability of a plurality of direct injection injectors can be improved. Further, since the fastening portions of the fixing bolts are positioned on both sides of the cam journal portion located between the adjacent clamp members, the load due to the fastening force of each fixing bolt on both sides is balanced with respect to the cam journal portion.

  Further, in each clamp member, since there is no other handle on the side opposite to the side where the handle portions adjacent to each other are arranged, the fuel supply pipe can be freely laid out using the space. it can. Since the handle portion of the clamp member and the fuel supply pipe are extended to the opposite sides, the bending rate and the length of each fuel supply pipe can be made equal, so that the fuel can be evenly distributed. Become.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic top view showing a main part of a direct injection gasoline engine to which the present invention is applied. As shown in the figure, the engine is an in-line four cylinder, and each direct injection injector 2 is arranged directly above each combustion chamber of each cylinder CL1, CL2, CL3, CL4 in the cylinder head 1. The direct injection injector 2 is a fuel injection valve that directly injects fuel into the combustion chamber. For example, the direct injection injector 2 injects fuel supplied at high pressure in accordance with the injection timing by opening and closing an electromagnetic valve. The structure may be the same as that of the injector, and the description of the structure is omitted. In addition, although it is a direct injection type gasoline engine in the example of illustration, it is applicable also to a direct injection type diesel engine.

  As shown in FIG. 2, the direct injection injector 2 includes a cylindrical body portion 2a, a small-diameter nozzle portion 2b provided on one end side (lower side in the drawing) of the body portion 2a, and the body portion 2a. It is formed so as to have a fuel supply pipe connecting portion 2c provided at an end (upper side in the drawing) coaxially and integrally. A cylindrical injector holding portion 1a is formed so as to protrude coaxially immediately above the combustion chamber 3 in the cylinder head 1, and the lower half of the direct injection injector 2 in the drawing is immersed in the injector holding portion 1a. Yes.

  In this engine, the rocker shaft holder 4 is assembled on the cylinder head 1, and the cam holder 5 is assembled on the rocker shaft holder 4. The rocker shaft holder 4 and the cam holder 5 are integrated with the cylinder head 1. It is. An injector insertion hole 5b is provided in the top plate portion 5a which is the upper surface of the cam holder 5, and the upper part of the direct injection injector 2 is exposed outwardly from the injector insertion hole 5b and is assembled to the injector insertion hole 5b. A corresponding portion of the direct injection injector 2 is sealed by the annular seal member 6.

  The direct injection injector 2 is not in a fixed state because it remains inserted in the injector holding portion 1a in the above state. Therefore, the direct injection injector 2 is fixed using a Y-shaped clamp member 7 shown in FIG.

  The clamp member 7 is made of, for example, an iron-based sintered material, has a Y shape as well shown in FIG. 3, and has a V-shaped engagement portion 7 a composed of two arms thereof, and a V-shaped engagement portion. It is formed so as to have a handle portion 7b linearly extending in the opposite direction from the branch portion of 7a. A pivot 7c having a spherical surface protrudes from the end of the handle portion 7b in the extending direction and facing the cylinder head 1 in the assembled state of the clamp member 7. A pivot support 8 is fixed to the cam holder 5 at a position to receive the pivot 7c in the assembled state. The pivot support 8 is for preventing buckling when the cam holder 5 is made of aluminum, and is preferably made of steel.

  Further, a bolt insertion hole 7d for inserting the fixing bolt 9 is provided at a position near the branch portion of the V-shaped engaging portion 7a, which is an intermediate portion of the handle portion 7b. A spherical seat 7e is formed in a portion of the bolt insertion hole 7d that contacts the head of the fixing bolt 9. The rocker shaft holder 4 is provided with a screw hole 4 a corresponding to the fixing bolt 9.

  A two-chamfered portion 2d is provided at the neck portion between the body portion 2a of the direct injection injector 2 and the fuel supply pipe connecting portion 2c. Both inwardly facing surfaces 7f of the V-shaped engaging portion 7a of the clamp member 7 are formed to be parallel surfaces aligned with the two chamfered portions 2d. The two inward surfaces 7f are fitted into the two chamfered portions 2d, and the lower surface in FIG. 2 of the V-shaped engaging portion 7a is brought into contact with the shoulder portion between the neck of the body portion 2a in the direct injection injector 2 and clamped. The member 7 can be engaged with the direct injection injector 2.

  As described above, the pivot 7c is placed on the pivot support 8, and the fixing bolt 9 is inserted into the bolt insertion hole 7d and screwed into the screw hole 4a, thereby rotating the direct injection injector 7 around the axis. The direct injection injector 7 is pressed in the immersion direction according to the fastening force of the fixing screw 9, and the direct injection injector 7 is fixed.

  A pipe plug 11 is screwed to the upper surface of the fuel supply pipe connecting portion 2c of the direct injection injector 2. One end of a fuel supply pipe 12 is coupled to the pipe plug 11, and the other end of the fuel supply pipe 12 is coupled to a fuel distribution pipe 13. The illustrated example is an in-line four-cylinder engine, and a direct-injection injector 2 is disposed in each of the cylinders CL1 to CL4. The fuel distribution pipe 13 is formed to have a length slightly shorter than the length of the direct injection injectors 2 in the direction of arrangement (cylinder row direction). The four direct injection injectors 2 are arranged in the same manner as in the assembled state, the fuel distribution pipes 13 are arranged so as to extend in the arrangement direction (cylinder row direction), and the pipes integrated with the respective direct injection injectors 2 The plug 11 and the fuel distribution pipe 13 are connected via the fuel supply pipes 12, and these members are sub-assembled as shown in FIG.

  Since the fuel supply pipe 12 is made of metal, the fuel distribution pipe 13 and each direct injection injector 2 are rigidly held together, so that the assembly operation of the direct injection injector 2 can be performed in the sub-assembly state. In addition, the dimensional tolerance can be set in the sub-assembly state. For example, by setting the dimensional tolerance of the position of the direct injection injector 2 relative to the fuel supply pipe 12 with the fuel distribution pipe 13 as a reference, the direct injection injectors 2 can be assembled without being aligned during assembly work on the engine. Assembly work becomes easy. In addition, by using the sub-assembly, the pressure inspection of the joint portion of the fuel supply pipe can be performed on the component supply side, and therefore the number of steps on the assembly side can be further reduced. At the same time, it is possible to reliably guarantee the durability of the cylinder-by-cylinder piping.

  Each direct injection injector 2 is inserted into each injector insertion hole 5b of the cam holder 5 (cylinder head 1) as shown by arrow A in FIG. 4, and the clamp member 7 is inserted into the direct injection injector 2 as described above in the fully inserted state. The direct injection injector 2 is fixed through a clamp member 7 with a fixing bolt 9 in a predetermined position in an engaged state. In this way, the direct injection injector 2 is assembled to the engine as shown in FIG. The fuel distribution pipe 13 is fixed to the top plate portion 5a of the cam holder 5 by screws.

  The clamp members 7 for fixing the direct injection injectors 2 may have the same shape as described above. As shown in FIG. 1, the handle portions 7b of the adjacent ones are adjacent to each other in a staggered manner. Are arranged to do. In the illustrated example, the clamp members 7 corresponding to the 1st and 2nd cylinders CL1 and CL2 and the clamp members 7 corresponding to the 3rd and 4th cylinders CL3 and CL4 are mutually connected to the handle portions 7b. Are opposed to each other. The alternate state is that each of the clamp members of the first and third cylinders CL1 and CL3 with respect to a line in the cylinder row direction, that is, a reference line L1 parallel to the camshaft 14a (14b), for example, as shown in FIG. The handle portion 7b of 7 (1) and 7 (3) extends at an angle θ1 with respect to the reference line L1, and the clamp members 7 (2) and 7 (7) of the second and fourth cylinders CL2 and CL4 The handle portion 7b of 4) extends so as to incline at an angle θ2 on the opposite side to the reference line L1.

  In this way, the adjacent handle portions 7b are inclined and extend to the opposite sides across the reference line L1, so that the adjacent handle portions 7b of the adjacent clamp members 7 are arranged so as to be adjacent to each other. be able to. Note that the angles θ1 and θ2 are arbitrary and may be any angles as long as the adjacent handle portions 7b do not interfere with each other.

  By doing so, it is possible to avoid interference between the handle portion 7b of the clamp member 7 and the handle portion 7b facing the clamp member 7, and to set the optimum positional relationship between the pivot 7c and the spherical seat 7e with the optimum lever ratio. Can do. Therefore, a sufficient pressing force against the direct injection injector 2 can be ensured without making the fastening force of the fixing bolt 9 excessive. Moreover, since the fastening part (working location with respect to the fixing bolt 9) of the adjacent clamp members 7 is close and the fastening work can be performed at a position escaped from the fuel supply pipe 12, workability is good.

  Further, since the direct injection injector 2 is fixed by the clamp member 7 in such a manner that the axial force of the fixing bolt 9 is distributed to the pivot 7c and the shoulder surface of the direct injection injector 2, a load is applied to the gasket on the seating surface of the cylinder head 1. Acts to seal the combustion gas. At this time, since the contact surfaces of the clamp member 7 and the fixing bolt 9 and the clamp member 7 and the pivot 7c are spherical as described above, the clamp member can be inclined, and dimensional errors and mounting of each part Regardless of the error, the pressing load of the direct injection injector 2 can be obtained stably.

  Further, the fuel supply pipe 12 and the clamp member 7 are arranged so as to extend toward opposite sides. In the layout of each fuel supply pipe 12, in the illustrated example, each fuel supply pipe 12 corresponding to the first and fourth cylinders CL1 and CL4 is bent so as to detour toward both ends of the fuel distribution pipe 13, The fuel supply pipes 12 corresponding to the second and third cylinders CL2 and CL3 are bent and connected to the central portion of the fuel distribution pipe 13 after being once moved away.

  By bending each fuel supply pipe 12 in this way, each fuel supply pipe 12 can be disposed in a range that does not interfere with the arrangement portion of the fixing bolt 9 of each clamp member 7. In addition, the assembling work of each clamp member 7 and the fastening work of each fixing bolt 9 can be performed without interfering with the fuel supply pipe 12, and the workability thereof is good. Further, since each fuel supply pipe 12 can be formed with the same length and bend, it is possible to realize common parts. Thereby, in the realization of the uniform fuel distribution, the fuel uniform distribution is facilitated without being affected by the variation of the fuel supply pipe 12.

  Further, in each cam journal portion disposed at both ends and between each cylinder in the cylinder row direction, the second cam journal portion 15 located between the first and second cylinders CL1 and CL2, and the third and fourth cylinders. With respect to the fourth cam journal portion 16 located between CL3 and CL4, the fixing bolt 9 of each clamp member 7 is arranged so as to sandwich the cam journal portions 15 and 16 in the cylinder row direction. As a result, the fixing bolt 9 and the pivot 7c are arranged on both sides of the cam journal portion 15 (16), so that the load due to the fastening force of each fixing bolt 9 on both sides is applied to the center line CJ of the cam journal portion 15 (16). The cam journal portion 15 (16) can be prevented from falling due to a biased load as described in the conventional example. Therefore, the bearing reliability of the cam journal portion 15 (16) can be ensured.

  Note that the present invention is also applicable to a marine engine whose crankshaft is directed in the vertical direction.

  The structure for fixing the fuel injection valve according to the present invention has good workability for fastening the fixing bolt, has a good load balance with respect to the cam journal part, and can evenly distribute the fuel, and is useful as a structure for fixing a direct injection injector or the like. .

It is a schematic top view which shows the principal part of the direct injection gasoline engine to which this invention was applied. It is a principal part fracture side sectional view showing the fixed structure of a direct injection injector. It is a perspective view which shows a Y-shaped clamp member. It is a side view which shows the sub-assembly state of a direct injection injector. It is explanatory drawing which shows the arrangement | positioning relationship of a Y-shaped clamp member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Direct injection injector 7 Clamp member 7a V-shaped engaging part 7b Handle part 12 Fuel supply pipe 13 Fuel distribution pipe

Claims (3)

A fuel injection valve fixing structure in which each direct injection injector disposed directly above each combustion chamber of a multi-cylinder engine is fixed to a cylinder head by a clamp member,
A fuel distribution pipe is arranged so as to extend in the cylinder row direction,
Each direct injection injector is connected from the fuel distribution pipe through the same number of fuel supply pipes as the direct injection injectors,
The clamp member extends in a direction opposite to the V-shaped engagement portion from a branch portion of the V-shaped engagement portion, a V-shaped engagement portion that engages with the direct injection injector, and the V-shaped engagement portion And having a handle fixed to the cylinder head,
In order from one end to the other end in the cylinder row direction, the handle portions of the adjacent clamp members face each other, and one of the handle portions facing each other does not interfere with the other in the cylinder row direction. A fuel injection valve fixing structure which is inclined with respect to a line . 2. The fuel injection valve fixing structure according to claim 1, wherein the handle portion of the clamp member and the fuel supply pipe are disposed so as to extend to mutually opposite sides. The fuel supply pipe is connected to both ends of the fuel distribution pipe, and besides the straight located between the two of the direct injector that connects to two of the direct injector located at both ends of the cylinder row direction 3. The fuel according to claim 2, wherein the fuel supply pipe connected to the injector is connected to a central portion of the fuel distribution pipe, and the length and the bending of each of the fuel supply pipes are the same. Injection valve fixed structure.

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