The present invention relates to an injector clamps and more particularly, to an injector clamping assembly for mounting a fuel injector of an internal combustion engine and a method therefor.

Background of the invention

Fuel injectors perform a task of admitting fuel into an internal combustion engine in which the injectors are mounted on a cylinder head. Many methods have been used for mounting or clamping the injectors to the cylinder head. For example, US patent 8047183B2 discloses a fuel injector, a clamping assembly and a method of mounting the fuel injector. The fuel injector is provided with notches that align with corresponding projections on an injector clamp and then the injector clamp is mounted on the cylinder head using bolts. However, making notches on the injector and corresponding projections on the injector clamp is very costly and less productive. Further, use of bolt can damage cylinder head threads during servicing which requires frequent removal of the injector resulting in a need to replace the cylinder head. The US patent 8047183B2 discloses the details of the injector clamp on the injector side but fails to disclose details of the injector clamp on the other side of the bolt.

Another US patent number 6116218 A discloses a fuel injector fixing device for a direct injection engine. The invention also discloses use of bolts for mounting of an injector clamp. As mentioned above, the solution is not service friendly and causes damage to the cylinder head on frequent removal of the bolt. Further, the invention discloses use of a separate bracket onto which the injector clamp is tightened for the mounting onto the cylinder head. Also, the injector clamp at both ends include resting faces that being flat cause misalignment of the injector. Few other drawbacks of the prior art are as follows:

1. Making the injector clamp straight and using a bigger spacer on the other end of injector clamp to match the clamping height of the injector is not assembly friendly.
2. Making the injector clamp straight and adding extra material in the cylinder head to match the clamping height in the injector increases the assembly cost. If the injector clamp is made straight, then for resting of the other end of the injector clamp lot of material need to be added on the cylinder head thereby increasing the cost.
3. Using bolts for clamping of the injector clamp makes the servicing difficult.
4. Using a stud for the clamping of the injector clamp without a nut in between the stud and the cylinder head results in damage and often rejection of the cylinder head due to high contact stress at a point where a stud shank ends on the cylinder head.

Accordingly, there exists a need to provide a clamping assembly for mounting a fuel injector of an internal combustion engine and a method therefor that overcomes the above mentioned problems in the prior art.

Objects of the invention

An object of the present invention is to eliminate thread slippage while assembling an injector clamp.
Another object of the present invention is to reduce damage to a cylinder head of an engine while servicing.

Yet another object of the present invention is to make use of cheaper and easy to manufacture parts.

Summary of the present invention

Accordingly, the present invention, in one aspect, provides a clamping assembly for mounting a fuel injector of an internal combustion engine. The internal combustion engine includes a cylinder head. The clamping assembly comprises a spacer, an injector clamp, a retainer, a first fastener, a second fastener and a washer.

The spacer is positioned on the cylinder head. The injector clamp is positioned on the cylinder head such that a first end of the injector clamp rests on the spacer and a second end holds and mounts the fuel injector onto the cylinder head. The injector clamp is an L-shaped reinforced injector clamp having two parallel flats on the second end thereof for aligning with corresponding flats on the fuel injector thereby holding and mounting the fuel injector onto the cylinder head in an inclined condition towards an intake side of the internal combustion engine.

The retainer for example, a stud is capable of securing to the injector clamp for positioning onto the cylinder head. The first fastener and the second fastener for example, flanged nuts are capable of tightening the retainer and thus the injector clamp onto the cylinder head. The washer for example, a spherical washer is adapted for holding the injector clamp along with the retainer and the fasteners onto the cylinder head.

In another aspect, the present invention provides a method for mounting the fuel injector of the internal combustion engine. The method includes positioning the fuel injector and the spacer onto the cylinder head. Further, the method includes positioning the injector clamp along with the retainer and the first fastener secured thereto onto the cylinder head such that the first end of the injector clamp rests on the spacer and the second end holds and mounts the fuel injector onto the cylinder head in the inclined condition towards the intake side of the internal combustion engine. Furthermore, the method includes placing the washer and the second fastener onto the retainer and tightening the injector clamp through the fasteners onto the cylinder head.

Brief description of the drawings

Figure 1 shows a perspective view of a clamping assembly for mounting a fuel injector of an internal combustion engine, in accordance with the present invention;

Figure 2 shows an exploded view of the clamping assembly of figure 1;

Figure 3 shows a sectional view of the clamping assembly of figure 1;

Figure 4 shows a sectional view of an injector clamp of the clamping assembly figure 1;

Figure 5 shows another sectional view of the injector clamp of figure 4; and

Figures 6a - 6c illustrate a method for mounting the fuel injector of the internal combustion engine, in accordance with the present invention.

Detailed description of the invention

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a clamping assembly and a method for clamping an injector of an internal combustion engine. The clamping assembly uses cheaper and easy to manufacture parts. The method of the present invention eliminates thread slippage while assembling an injector clamp and reduces damage to a cylinder head of the engine while servicing.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring now to figures 1 to 6c, in one first aspect, a clamping assembly (100) for mounting a fuel injector (150) of an internal combustion engine (not shown) in accordance with the present invention is shown. Specifically, the clamping assembly (100) is mounted on a cylinder head (200) of the internal combustion engine (herein after ‘the engine’). The clamping assembly (100) comprises a spacer (10), an injector clamp (20), a retainer (30), a first fastener (40A), a second fastener (40B) and a washer (50). It is further understood that the present invention is not limited to one fuel injector (150) of the engine, but may be applied to any number of the fuel injectors (150).

The spacer (10) is positioned and tightened on the cylinder head (200). The injector clamp (20) is positioned in a mounting hole (not numbered) of the cylinder head (200). The injector clamp (20) includes a first end (not numbered) and a second end (not numbered). The second end includes two parallel flats/faces (not numbered) for aligning with corresponding flats (not numbered) on the fuel injector (150). The two parallel flats on the injector clamp (20) when placed over the corresponding flats on the fuel injector (150) enable the fuel injector (150) to get assembled in a desired orientation. The injector clamp (20) is positioned on the cylinder head (200) such that the first end rests on the spacer (10) and the two parallel flats on the second end aligns with the corresponding flats on the fuel injector (150) (herein after ‘the injector (150)’) thereby holding and mounting the injector (150) in an injector bore (not numbered) onto the cylinder head (200) in the desired orientation. Specifically, the first end of the injector clamp (20) is in point contact with the spacer (10) and the second end of the injector clamp (20) is in point contact with the injector (150).

Preferably, the injector clamp (20) is an L-shaped reinforced injector clamp as shown in figures 4 and 5. However, it is understood that the injector clamp (20) can be designed in any suitable shape. The ‘L’ shaped injector clamp (20) is designed to mount the injector (150) in the inclined condition on the cylinder head (200) at an angle towards intake side (not shown) of the engine. The injector clamp (20) is designed in ‘L’ shape with sufficient reinforcement to take care of clamping and bending load and combustion pressures that are transferred to the injector clamp (20) from the injector (150). The section of the injector clamp (20) itself serves as the reinforcement which is made up of 42CrMo4.

The injector clamp (20) is positioned on the cylinder head (200) by the retainer (30). The retainer (30) is secured to the injector clamp (20) and then to the cylinder head (200) for positioning the injector clamp (20) onto the cylinder head (200). The injector clamp (20) is tightened to the cylinder head (200) by tightening the retainer (30) thereon using the fasteners (40A, 40B). The first fastener (40A) is secured to one end (not numbered) of the retainer (30) and the second fastener (40B) is secured to another end (not numbered) of the retainer (30). Specifically, the retainer (30) is a stud and the fasteners (40A, 40B) are flanged nuts that rest on the cylinder head (200) to transfer preload thereto from the retainer (30). The injector clamp (20) along with the retainer (30) is held between the washer (50) and the fasteners (40A, 40B). In an embodiment, the washer (50) is a spherical washer. However, it is understood that any other types of retainer (30), the fasteners (40A, 40B) and the washer (50) known in the art can also be used.

Referring again to figures 6a to 6c, in another aspect, a method for mounting the injector (150) of the engine is illustrated. Specifically, the method is described in conjunction with the clamping assembly (100) of the present invention. The method clamps the injector (150) in several steps which are as described below.

First, the fuel injector (150) and the spacer (10) are positioned onto the cylinder head (200). Then the injector clamp (20) having the retainer (30) along with the first fastener (40A) secured thereto is positioned onto the cylinder head (200). The injector clamp (20) is positioned in such a way that the first end of the injector clamp (20) rests on the spacer (10) in point contact and the two parallel flats on the second end aligns with the corresponding flats on the injector to hold and mount the injector (150) onto the cylinder head (200) in the inclined condition towards the intake side of the engine. Then, the washer (50) and the second fastener (40B) are placed onto the retainer (30). Finally, the injector clamp (20) is tightened onto the cylinder head (200) by tightening the retainer (30) through the fasteners (40A, 40B).

Advantages of the invention

1. The flat faces on the injector (150) and the injector clamp (20) are cheaper and easier to manufacture.
2. The injector clamp (20) with the injector (150) is mounted on the cylinder head (200) using the stud/retainer (30) thereby making the cylinder head (200) lesser susceptible to damages.
3. Since the stud/retainer (30) is used with one nut/ first fastener (40A) at one end for mounting onto the cylinder head (200). Over this, the injector clamp (20) is placed and tightened with another nut/ second fastener (40B), thus only the second fastener (40B) needs to be removed for removal of the injector clamp (20) during servicing.
4. The injector clamp (20) is directly mounted to the cylinder head (200) without any intermediate brackets.
5. The clamping height location in the injector (150) from a middle deck (not shown) of the cylinder head (200) for mounting the injector clamp (20) is very high, In other words, the distance between the mounting support point and the injector clamp (20) resting face on the injector (150) is high. Since the gap is high, the injector clamp (20) is designed so as to accommodate the gap and provide sufficient stiffness.
6. As the resting faces at the two ends of the injector clamp (20) are spherical, the load at both the ends of the injector clamp (20) is applied centrally and misalignment in the positions of the injector bore and of the injector clamp mounting hole due to tolerances is taken care.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

,CLAIMS:We claim:

1. An clamping assembly (100) for mounting a fuel injector (150) of an internal combustion engine, the internal combustion engine having a cylinder head (200), the clamping assembly (100) comprising:
a spacer (10) positioned on the cylinder head (200);
an injector clamp (20) positioned on the cylinder head (200) such that a first end thereof resting on the spacer (10) and a second end thereof holding and mounting the fuel injector (150) onto the cylinder head (200);
a retainer (30) capable of securing to the injector clamp (20) for positioning onto the cylinder head (200);
a first fastener (40A) and a second fastener (40B) capable of tightening retainer (30) and thus the injector clamp (20) onto the cylinder head (200); and
a washer (50) holding the injector clamp (20) along with the retainer (30) and the fasteners (40A, 40B) onto the cylinder head (200),
characterized in that, the injector clamp (20) is an L-shaped reinforced injector clamp having two parallel flats on the second end thereof for aligning with corresponding flats on the fuel injector (150) thereby holding and mounting the fuel injector (150) onto the cylinder head (200) in an inclined condition towards an intake side of the internal combustion engine.

2. The clamping assembly (100) as claimed in claim 1, wherein the retainer
(30) is a stud.

3. The clamping assembly (100) as claimed in claim 1, wherein the fasteners
(40A, 40B) is flanged nuts.

4. The clamping assembly (100) as claimed in claim 1, wherein the washer
(50) is a spherical washer.

5. A method for mounting a fuel injector (150) of an internal combustion
engine, the internal combustion engine having a cylinder head (200), the method comprising:
positioning the fuel injector (150) and a spacer (10) onto the cylinder head (200);
positioning an injector clamp (20) having a retainer (30) along with a first fastener (40A) secured thereto onto the cylinder head (200) such that a first end of the injector clamp (20) rests on the spacer (10) and a second end holds and mounts the fuel injector (150) onto the cylinder head (200) in an inclined condition towards an intake side of the internal combustion engine;
placing a washer (50) and a second fastener (40B) onto the retainer (30); and
tightening the injector clamp (20) through the fasteners (40A, 40B) onto the cylinder head (200).

6. The method as claimed in claim 6, wherein the injector clamp (20) is an L-
shaped reinforced injector clamp having two parallel flats on the second end thereof for aligning with corresponding flats on the fuel injector (150) thereby holding and mounting the fuel injector (150) onto the cylinder head (200) in the inclined condition towards the intake side of the internal combustion engine.

7. The method as claimed in claim 6, wherein the retainer (30) is a stud.

8. The method as claimed in claim 6, wherein the fasteners (40A, 40B) is
flanged nuts.

9. The method as claimed in claim 6, wherein the washer (50) is a spherical
washer.