JP2585151Y2 - Fuel injection device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a diesel engine unit injector. 2. Description of the Related Art In order to mount a unit injector of a diesel engine to a cylinder head, Japanese Utility Model Laid-Open Publication No.
As disclosed in Japanese Patent Application Laid-Open No. 7978, there is known a device in which a body in which a plunger of a unit injector is housed is pressed and held by a clamp having a tip branched in a U-shape. [0003] However, when the unit injector 2 is fastened to the cylinder head 1 by the clamp 4 as shown in FIG. 4, the flange 5b of the unit injector 2 is brought into contact with the convex portion 44 provided on the clamp 4. Because of the point contact, the flange 5b is bent by the fastening pressure of the bolt 7, and the body 21 and the plunger chamber 30 may be deformed as shown in FIG. In some cases, fuel injection cannot be performed. Accordingly, an object of the present invention is to provide a fuel injection device for an internal combustion engine that prevents deformation of a plunger chamber of a unit injector. [0005] The present invention provides a unit-in
Protrude annularly with a gap from the body outer surface of the ejector
The upper and lower flanges are
With the plunger guide toward the rocker arm
Supports the biasing spring and is provided at the tip of the clamp.
A clamp that fits into the gap between the flanges so as to sandwich the body
Point of the U-shaped part of the pump
And project the other end of the clamp to the cylinder head wall.
Contact and insert through the bolt hole drilled in the middle of the clamp
Tighten the bolts and secure the clamp to the cylinder head.
To fix the unit injector
In the vertical direction on the outer surface of the body,
Rib that connects the upper and lower flanges
And a U-shaped portion provided with a rib groove to be engaged with this rib . The unit injector is located above the outer peripheral surface of the body.
Provided at the clamp tip in the gap between the flange and the lower flange
The U-shaped part is fitted so that the body
Fix the unit injector to the cylinder head with
At this time, the clamps are
Even if you press the flange below the ejector,
Upper flange supporting the spring and convex part of U-shaped part
Rib that connects and connects the lower flanges
A U-shaped part is provided, and a rib groove for engaging with this rib is formed in the U-shaped part.
Beam, restricting flange curvature and unit injection
Prevent deformation of the body of the Kuta and deformation of the plunger chamber
Can be. This embodiment shows an example in which the present invention is applied to a unit injector provided in a cylinder head of a diesel engine. As shown in FIGS. 1 to 3, a unit injector 2 which is driven by a rocker arm 8 driven by a cam 9 which rotates in synchronization with the engine rotation and pressurizes and injects fuel is attached to the cylinder head 1. . When the plunger 3 of the unit injector 2 is pushed down through the guide 31 by the rocker arm 8, the fuel is pressurized, and the fuel is injected while lifting a needle valve (not shown) from the fuel injection hole 20 at the tip. When the plunger 3 is raised by the spring 32 in the non-lift section of the cam 9, fuel is sucked. The fuel injection amount and injection timing are adjusted by a control mechanism (not shown) housed inside the fuel control unit 2A. The unit injector 2 includes a clamp 4
The cylinder 21 is fixed to the cylinder head 1 by means of a flange 5a.
5b are protruded respectively. The upper surface of the upper flange 5a supports a spring 32 for urging the guide 31 of the plunger 3 toward the rocker arm 8. The flanges 5a, 5b on the outer peripheral surface of the body 21
Is formed at the tip of the clamp 4 and
The U-shaped part 41 that fits across the outer peripheral surface engages and clamps.
4 Contact the protrusion 10 at the other end with the cylinder head wall,
The bolt inserted into the bolt hole 43 drilled in the middle of the clamp 4
And fix the clamp 4 to the cylinder head 1.
As a result , the convex portion 44 of the U-shaped portion 41 is
b is pressed against the cylinder head 1 to fix the unit injector 2 at a predetermined position. A rib 6 is provided on the body 21 between the flanges 5a and 5b in the direction in which the clamp 4 enters.
Are provided to improve the rigidity of the body 21. The rib 6 is formed in a rectangular shape extending from the body 21 as a base end to the vicinity of the outer periphery of the flanges 5a, 5b while connecting the flanges 5a, 5b, and has a substantially uniform thickness in cross section. The U-shaped portion 41 of the clamp 4 is provided with a rib groove 42 which engages with the rib 6. The rib groove 42 does not push the rib 6 at the position where the clamp 4 has entered the unit injector 2 most. The clamp 4 is fitted to the body 21 so as to be freely detachable. The operation will be described below. When assembling the unit injector 2, the unit injector 2 is erected at a predetermined position on the cylinder head 1, and the U-shaped portion 41 of the clamp 4 is fitted between the flanges 5 a and 5 b of the unit injector 2 to form After pushing in until the 42 engages with the rib 6, the bolt 7 inserted into the bolt hole 43 is fastened, and the convex portion 44 presses the flange 5 b and fixes it to the cylinder head 1. The convex portion 44 of the clamp 4 presses the flange 5b to bend by the tightening pressure of the bolt 7 or the like.
body 21 and plunger chamber 3 to restrict the displacement of b
0 can be prevented, and the plunger can be prevented from galling and sliding failure. In the above embodiment, the clamp 4 has a groove 4
2 is provided so that the clamp 4 does not push the rib 6, but the depth of the U-shaped portion may be set large so that the rib 6 does not abut the clamp 4. In the above embodiment, one rib 6 is provided.
Can be improved in strength. As described above, according to the present invention, the unit
The upper flange and lower flange on the outer peripheral surface of the injector body
The U-shaped part provided at the tip of the clamp in the gap between the flanges
Fit so that the outer circumference is sandwiched, and clamp the unit
Bolts when fixing the ejector to the cylinder head.
The force causes the clamp to move below the unit injector.
The spring is supported on the outer peripheral surface of the body even when the flange is pressed
The upper flange and the lower part that makes point contact with the convex part of the U-shaped part.
A U-shaped part is provided for a rib for connecting and reinforcing the flanges of
Because a rib groove is provided in the
The curvature of the unit to change the body of the unit injector.
The deformation of the shape and plunger chamber can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a perspective view showing the entire unit injector. FIG. 4 is a partial sectional view of a cylinder head showing a conventional example. FIG. 5 is a partial sectional view of a unit injector showing a conventional example. [Description of Signs] 1 Cylinder head 2 Unit injector 21 Body 3 Plunger 4 Clamp 41 U-shaped part 42 Rib groove 44 Convex part 6 Rib

Continuation of the front page (56) References JP-A-53-27718 (JP, A) JP-A-4-171267 (JP, A) JP-A-59-19973 (JP, U) JP-A-64-47978 (JP, A) , U) Hikaru Hei 3-122265 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02M 57/02 330 F02M 61/14 320

Claims (1)

(57) [Claims for registration of utility model] With a gap from the outer peripheral surface of the unit injector body
An upper flange and a lower flange
Lock the plunger guide on the upper flange
Supports the spring biasing toward the arm and clamps
The gap between the flanges provided at the tip so as to sandwich the outer periphery of the body
The U-shaped projection of the clamp that fits on the lower flange
Point contact with the surface and the protrusion at the other end of the clamp into the cylinder
-Contact the head wall and open the bolt
To the cylinder head by tightening the bolts
Secure the clamp and secure the unit injector.
In the direction of penetration of the U-shaped part
And the upper and lower flanges are
A connecting rib and a rib groove engaging with this rib are formed in the U-shaped portion.
The fuel injection system for an internal combustion engine, characterized by comprising.