JPH1122597A - Nozzle clamp for diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a nozzle clamp without reducing the fixing function to an injection nozzle. SOLUTION: The raw material of a nozzle clamp 2 is made of a sintered metal or a precision casting, and a rocker shaft hole 2c of a cylinder face having an opening section at the opposite position to a cylinder head and having the center angle larger than 180 deg. is formed on the clamp raw material. The machining occupying a large ratio of the manufacturing cost is reduced to the utmost, and the manufacturing cost of the nozzle clamp 2 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle clamp for fixing an injection nozzle to a cylinder head of a diesel engine, and more particularly to a method for reducing a manufacturing cost without deteriorating a fixing function for the injection nozzle. The present invention relates to a nozzle clamp described above.

[0002]

2. Description of the Related Art In recent years, as shown in FIGS. 2 and 3, for example, a tip R portion 2a of a nozzle clamp 2 pivotally attached to a rocker shaft 1 is brought into contact with a shoulder 3a of an injection nozzle 3 from above. Then, the nozzle clamp 2 is fixedly fastened to the cylinder head with a fastening bolt (not shown), and the injection nozzle 3 is pressed and fixed to the cylinder head, so that the nozzle clamp 2 is pivotally attached to the rocker shaft 1 (not shown). It can be effectively used as a spacer. 2
b is a fastening bolt hole, and 2c is a rocker shaft hole.

[0003] In constructing such a nozzle clamp 2, a clamp material conventionally formed of a cast or forged product is used. Since the two side surfaces 2d constituting the thrust surfaces are machined to obtain a predetermined accuracy, the manufacturing cost of the nozzle clamp is high.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the manufacturing cost of a nozzle clamp without lowering the fixing function for an injection nozzle.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which a clamped rough member is made of a sintered metal or a precision cast product, and a center angle of an opening portion is set at a position facing a cylinder head. A rocker shaft hole having a cylindrical surface larger than 180 degrees is formed in the rough clamp material.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing one embodiment of a nozzle clamp for a diesel engine according to the present invention. Parts having the same functions as those of the conventional example shown in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the present embodiment, the roughly L-shaped clamp rough is made of a sintered metal or a precision casting. If the clamp material is made of sintered metal,
It is only necessary to select a raw material composition that emphasizes mechanical characteristics, dimensional accuracy, machinability and wear resistance characteristics, etc.When forming a clamp coarse material with a precision cast product, a precision material such as the conventionally known lost wax method is used. Although the dimensional accuracy of the rough clamp material can be increased by employing the casting method, other precision casting methods can be employed. Further, by setting the mold split direction at the time of forming the coarse material to be vertically divided, the tip R portion 2a of the obtained nozzle clamp 2 (clamp coarse material) and the bolt hole 2 are formed.
b and the dimensional accuracy of both side surfaces 2d can be maintained at predetermined levels.

[0008] Then, by bending off the bent corners of the clamped rough material as shown by hatching, the center angle with the opening facing the cylinder head (not shown) being larger than 180 degrees and within about 270 degrees. The rocker shaft hole 2c is formed by a cylindrical surface having a central angle (in the embodiment, the rocker shaft hole 2c is formed by a cylindrical surface having a central angle of about 230 degrees). The rocker shaft hole 2c
A conventionally known general-purpose turning machine can be used for cutting.

That is, when the clamp coarse material is formed of a sintered metal or a precision cast product as in the present embodiment, the nozzle clamping 2 (or the vertical direction) is set by, for example, setting the molding direction at the time of forming the coarse material. The dimensional accuracy of the clamp material) can be ensured. For this reason, as in the prior art, the tip R portion 2a, the bolt hole 2b, and the side surface 2d of the clamp coarse material are used.
There is no need to machine each of the nozzle clamps 2 and the nozzle clamps 2 of desired accuracy can be obtained only by forming the rocker shaft holes 2c, so that the manufacturing cost of the nozzle clamps 2 can be reduced.

Further, since the rocker shaft hole 2c is constituted by a cylindrical surface having a central angle larger than 180 degrees and having an opening at a position facing the cylinder head (not shown), the rocker shaft hole 2c can be tightened by a tightening bolt (not shown). Since the abutment area between the rocker shaft 1 and the nozzle clamp 2 can be kept the same as in the related art, and the nozzle clamp 2 can be stably supported on the rocker shaft 1, the function of fixing the injection nozzle 3 to the injection nozzle 3 can be ensured. Regardless, the weight and cost of the clamp blank can be reduced. further,
The central angle of the cylindrical surface forming the rocker shaft hole 2c is 18
Since it is larger than 0 degrees, the nozzle clamp 2 inserted into the rocker shaft 1 does not fall off carelessly, and the workability of assembling the rocker shaft 1 does not deteriorate.

[0011]

As is apparent from the above description, in the present invention, since the rough material of the nozzle clamp is formed of a sintered metal or a precision cast product, the direction of the mold during the forming of the rough material is, for example, up and down. Since the dimensional accuracy of the nozzle clamp (coarse material of the clamp) can be secured by setting the ratio relatively, the machining cost, which accounts for a large proportion of the manufacturing cost, can be reduced as much as possible, and the manufacturing cost of the nozzle clamp can be reduced. .

Further, since the rocker shaft hole is formed by a cylindrical surface having a central angle larger than 180 degrees with the opening facing the cylinder head as an opening, the nozzle clamp is attached to the rocker shaft when tightening with the tightening bolt. Despite being able to stably support and maintain the fixing performance of the injection nozzle, the weight (coarse material cost) of the clamp material can be reduced, and the nozzle clamp inserted into the rocker shaft is inadvertent. In this way, it is possible to prevent the dropping of the rocker shaft and prevent the workability of assembling the rocker shaft from deteriorating.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a nozzle clamp for a diesel engine according to the present invention.

FIG. 2 is a plan view showing a conventional example of a nozzle clamp.

FIG. 3 is a side view of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rocker shaft 2 Nozzle clamp 2a Tip R part 2b Bolt hole 2c Rocker shaft hole 2d Side surface 3 Injection nozzle 3a Shoulder

Claims (1)

[Claims] An end of a nozzle clamp pivotally attached to a rocker shaft is brought into contact with a shoulder formed on an injection nozzle from above, and the nozzle clamp is fastened and fixed to a cylinder head with a fastening bolt. In a diesel engine in which the injection nozzle is pressed and fixed to the cylinder head, the rocker shaft hole formed by a sintered metal or precision cast product with a cylindrical surface having a central angle larger than 180 degrees with the opening facing the cylinder head as an opening A nozzle clamp for a diesel engine, wherein the nozzle clamp is formed of a roughened clamped material.