JPH061771U - Fuel injection device for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the deformation of the plunger of the unit injector. In a unit injector 2 erected on a cylinder head 1 by a fitting clamp 4, flanges 5a and 5b are provided on a body 21 of the unit injector 2.
On the other hand, ribs 6 that connect to the flanges 5a and 5b are provided on the side surface of the body 21 along the fitting direction of the clamp 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a diesel engine unit injector.

[0002]

[Prior art]

 To mount the unit injector of the diesel engine to the cylinder head, press the body containing the plunger of the unit injector with a clamp having a U-shaped branch as disclosed in Japanese Utility Model Laid-Open No. 64-47978. It is known to hold.

[0003]

[Problems to be solved by the device]

 However, when the unit injector 2 is fastened to the cylinder head 1 with the clamp 4 as shown in FIG. 4, the flange 5b of the unit injector 2 is in point contact with the convex portion 44 provided on the clamp 4, so that the flange 5b is bolted. The body 21 and the plunger chamber 30 may be deformed as shown in FIG. 5 due to the fastening pressure of No. 7, and the fuel may not be injected due to galling or sliding failure of the plunger.

Therefore, an object of the present invention is to provide a fuel injection device for an internal combustion engine that prevents deformation of the plunger chamber of the unit injector.

[0005]

[Means for Solving the Problems]

 According to the present invention, in a unit injector that is erected on a cylinder head by a fitting clamp, a flange is provided on a body of the unit injector, and a flange is connected to a side surface of the body along a fitting direction of the clamp. Install ribs vertically.

[0006]

[Effect] When the unit injector is fastened to the cylinder head with the clamp, even if the clamp presses the flange of the unit injector by the fastening pressure of the bolt, the rib protrudes from the body toward the outer circumference of the flange. It is possible to prevent the deformation of the body and the plunger chamber by regulating the bending.

[0007]

【Example】

 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 that is driven by a rocker arm 8 that is driven by a cam 9 that rotates in synchronism with engine rotation and that pressurizes and injects fuel is attached to the cylinder head 1. To be When the plunger 3 of the unit injector 2 is pushed down by the rocker arm 8 via the guide 31, the fuel is pressurized, and the fuel is injected from the fuel injection hole 20 at the tip while lifting the needle valve (not shown). When the plunger 32 is pulled up by the spring 32 in the non-lift section of the cam 9, the 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 is fixed to the cylinder head 1 by a clamp 4, and therefore, the body 21 of the unit injector 2 has two flanges 5a that are horizontally oriented at two positions with a predetermined interval in the vertical direction. 5b is projected respectively. The upper surface of the flange 5a located above supports a spring 32 for biasing the guide 31 of the plunger 3 toward the rocker arm 8.

Between the flanges 5 a and 5 b, the U-shaped portion 41 of the U-shaped clamp 4 whose tip engages with the outer periphery of the body 21 is fitted, and the bolt 7 inserted into the bolt hole 43 is inserted. By fastening to the cylinder head 1, the convex portion 44 of the U-shaped portion 41 presses the flange 5b 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 so as to extend in the direction in which the clamp 4 enters, thereby improving the rigidity of the body 21. The rib 6 is formed in a rectangular shape extending from the body 21 to the outer periphery of the flanges 5a and 5b toward the outer periphery while connecting the flanges 5a and 5b to each other, and has a substantially uniform cross section.

The U-shaped portion 41 of the clamp 4 is provided with a rib groove 42 that engages with the rib 6, so that 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 removably fitted into the body 21.

With the above-mentioned configuration, the operation will be described.

When the unit injector 2 is assembled, the unit injector 2 is erected at a predetermined position of 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 a rib. After the groove 42 is pushed in until it engages with the rib 6, the bolt 7 inserted in the bolt hole 43 is fastened, and the convex portion 44 presses the flange 5b to fix it to the cylinder head 1.

The convex portion 44 of the clamp 4 tries to press the flange 5b to bend it by the tightening pressure of the bolt 7 or the like, but the rib 6 protruding from the body 21 restricts the displacement of the flange 5b, so that the body 21 does not move. Also, the deformation of the plunger chamber 30 can be prevented, and the galling of the plunger and the sliding failure can be prevented.

Although the groove 42 is provided in the clamp 4 so that the clamp 4 does not push the rib 6 in the above-described embodiment, the depth of the U-shaped portion is set so that the rib 6 and the clamp 4 do not come into contact with each other. May be set to a large value.

Further, although one rib 6 is provided in the above embodiment, the strength of the flange 5b can be improved by providing a plurality of ribs 6.

[0017]

As described above, according to the present invention, the flange of the unit injector into which the clamp fits is provided with a rib projecting along the intrusion direction of the clamp, and a groove that engages with the rib is formed in the clamp. Since it is provided, the deformation of the flange of the unit injector can be suppressed and the deformation of the plunger can be prevented.

[Brief description of 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 an entire unit injector.

FIG. 4 is a partial cross-sectional view of a cylinder head showing a conventional example.

FIG. 5 is a partial cross-sectional view of a unit injector showing a conventional example.

[Explanation of symbols]

 1 Cylinder Head 2 Unit Injector 21 Body 3 Plunger 4 Clamp 41 U-Shaped Section 42 Rib Groove 44 Convex Section 6 Rib

Claims (1)

[Scope of utility model registration request] 1. A unit injector erected on a cylinder head by a fitting clamp, wherein a flange is provided on a body of the unit injector,
A fuel injection device for an internal combustion engine, wherein a rib connecting to a flange is vertically provided on a side surface of the body along a direction in which the clamp is fitted.