DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
A FUEL INJECTOR ASSEMBLY WITH THREADED BUSH FOR NOZZLE OPENING PRESSURE ADJUSTMENT AND METHOD THEREOF

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present invention claims priority from Indian patent application numbered IN 202241059560 filed on 18th October, 2022.

FIELD OF INVENTION
[002] The present subject matter described herein, in general, relates to nozzle opening pressure adjustment for fuel injector assembly and more specifically relates threaded bush provided for nozzle opening pressure adjustment for fuel injector assembly.

BACKGROUND OF THE INVENTION
[003] At present, fuel injector assembly is designed to inject the fuel in atomized form for efficient combustion. In present design nozzle opening pressure is adjusted by means of shims. Shims are (used to control Nozzle opening pressure of injectors). Shims vary in thickness from (100 microns which is 0.1mm). For varying the performance offuel injector various sizes of shims are inserted and checked to attain the desired nozzle operating pressure. This checking of various sizes of shims is a lengthy process and requires a lot of time.
[004] Thus, as an alternative solution, a threaded bush is mounted in place of shims for adjusting the nozzle opening pressure in fuel injector assembly.

OBJECTS OF THE INVENTION
[005] Main object of the present invention is to provide adjustable nozzle opening pressure in fuel injector assembly.
[006] Another object of the present invention is to provide adjustable nozzle opening pressure in fuel injector assembly by mounting a threaded bush.

SUMMARY OF THE INVENTION
[007] Before the present system is described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a threaded bush for nozzle opening pressure adjustment of fuel injector assembly, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[008] The present subject matter described herein, in general, relates to threaded bush provided for nozzle opening pressure adjustment for fuel injector assembly. In the present invention, the nozzle opening pressure of the fuel is controlled by a threaded bush thus eliminating using various sizes of shims to adjust the nozzle opening pressure.

BRIEF DESCRIPTION OF THE DRAWINGS
[009] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing:
[0010] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0011] Figure 1 illustrates a fuel injector assembly.
[0012] Figure 2 illustrates a fuel injector assembly.
[0013] Figure 3 illustrates a threaded bush.
[0014] Figure 4 illustrates the flow chart of the assembly of fuel injector assembly of the present invention.
[0015] Figure 5 illustrates the isometric view of the fuel injector assembly of the present invention.
[0016] Figure 6 illustrates the isometric exploded view of the fuel injector assembly.
[0017] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION
[0018] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0019] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0020] The present subject matter relates to a threaded bush provided for nozzle opening pressure adjustment for fuel injector assembly. In the present invention, the nozzle opening pressure of the fuel is controlled by a threaded bush thus eliminating using various sizes of shims to adjust the nozzle opening pressure.
[0021] Referring to figure 1-6, the present invention relates to a fuel injector assembly (100) comprises of nozzle assembly (10), a fuel injector body assembly (11) and fuel inlet unit (12). The nozzle assembly (10) comprises of a nozzle (6) mounted on a nozzle nut (7). The nozzle (6) is provided with a guide hole (13). An insert (5) is mounted on the guide hole (13). A seat pin (4) and a spring (3) mounted on the insert (5). The fuel injector body assembly (11) comprises of a fuel injector body (1) with threading for mounting said nozzle nut (7) and a threaded bush (2). The injector body assembly (11) comprises of another opening for mounting a fuel inlet unit (12). The fuel inlet unit (12) comprises of alocking ring (not shown in the figure) is mounted on the inlet pipe followed by an item cone (9). This fuel inlet unit (12) is mounted on the injector body assembly (11).
[0022] A threaded bush (2) is mounted in the threaded injector body (1) for adjusting the predetermined nozzle opening pressure. The number of threads of threaded bush (2) is adjusted with the injector body (1) for varying the nozzle opening pressure of said injector assembly. The injector body assembly (11) is assembled with the nozzle assembly (10) using the threads provided on nozzle assembly nut and injector body (1).
[0023] The method of assembling of fuel injector comprises of various stages:
Stage 1: Assembling of nozzle assembly (10).
a) A nozzle (6) is placed on a nozzle nut (7). An insert (5) is located on to a nozzle guide hole (13). A seat pin (4) is placed into the insert (5) and a spring (3) is assembled into the insert (5).
Stage 2: Assembling of Injector body assembly (11).
a) A threaded injector body (1) is assembled with a threaded bush (2). The stage 1 nozzle assembly (10) is assembled with the injector body assembly (11) and checked with a predefined torque.
Stage 3: Assembling of fuel inlet unit (12).
a) A locking ring is assembled in an inlet pipe (8) followed by an item cone (9) and it is checked for free movement of cone (9) inside the inlet pipe (8). The assembled fuel inlet unit (12) is checked with flow test and later the inlet pipe is tightened with injector body assembly (11) with a predefined torque.
Stage 4: Adjusting of nozzle opening pressure.
a) The Injector assembly (100) for nozzle opening pressure (285-291 bar) is checked and adjusted accordingly with the threaded bush.
[0024] Figures 1-6 are now described using the reference numbers stated in the below table.

Reference Numeral Description
100 Fuel Injector assembly
1 Injector body with threading
2 Threaded Bush
3 Spring
4 Seat pin
5 Insert
6 Nozzle assembly
7 Nozzle nut
8 Fuel inlet pipe
9 Item cone
10 Nozzle assembly
11 Fuel injector body assembly
12 Fuel inlet unit
13 Guide hole

,CLAIMS:1. A fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment comprising:
a nozzle assembly (10);
an injector body assembly (11) configured with internal threads for mounting a threaded bush (2) for adjusting the nozzle opening pressure; and
a fuel inlet unit (12) configured to be mounted on the injector body assembly (11).

2. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said nozzle assembly (10) comprises of a nozzle (6), a nozzle nut (7), an insert (5), a seat pin (4) and a spring (3).

3. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said injector body assembly (11) comprises of a injector body (1) and a threaded bush (2) wherein, injector body assembly (11) is provided with threads for mounting the nozzle assembly (7).

4. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said fuel inlet unit (12) comprises of a fuel inlet pipe (8), a locking ring and an item cone (9).

5. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said nozzle (6) is configured to be mounted in the nozzle nut (7).

6. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said insert (5) is configured to be mounted on a guide hole (13) provided on nozzle (6).

7. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said seat pin (4) along with spring (3) is configured to be mounted on the insert (5).

8. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, wherein said locking ring is configured to be mounted on the inlet pipe followed by the item cone (9) to form the fuel inlet unit (12).

9. The fuel injector assembly (100) with threaded bush for nozzle opening pressure adjustment as claimed in claim 1, said threaded bush (2) is configured to vary the nozzle opening pressure by adjusting the number of threads on the bush (2) with the injector body (1).

10. The method for assembling of fuel injector assembly (100) comprising the steps of:
• assembling nozzle assembly (10);
mounting a nozzle assembly (6) on a nozzle nut (7);
mounting an insert (5) on the guide hole of the nozzle assembly (6);
mounting a seat pin (4) on the insert (5);
mounting a spring (3) on the insert (5);
• assembling fuel injector body assembly (11);
mounting the threaded bush (2) on the injector body (1);
• assembling fuel inlet unit (12) by;
mounting a locking ring followed by an item cone (9) on a fuel inlet pipe (8);
checking for free movement of cone (9) inside the inlet pipe (8);
checking the assembled inlet pipe (8) with flow test;
• mounting fuel inlet unit (12) the on injector body assembly (11) with a predefined torque;
• mounting the injector body assembly (11) on the nozzle assembly (10);
• checking the injector assembly (100) for nozzle opening pressure; and
• adjusting the threaded bush (2) to adjust the opening pressure to a predefined value.