HK1001410B - Push-in oil cooling nozzle - Google Patents

Description

Piston coolant sprayers for internal combustion engines are used to project a coolant such as oil against the bottom of the piston, i.e. against the piston face outside the blast chamber, or into a piston tunnel.

The piston coolant sprinklers normally used are retracted parts, fixed to the engine crankcase and communicating with a coolant intake orifice.

A known technique, for example described in document DE-A-19 57 499, is to provide a single-block sprinkler body, bounded by a support face and an opposite attachment face, with an axial drill to be passed through a fluid inlet and attachment vis-a-vis. The axial drill communicates with a cross-sectional drill connected to a coolant outlet injection line. The vis-a-vis is conformed and adapted to keep the sprinkler body supported by its support face zone against the periphery of a fluid inlet hole in the engine block, and to transmit the coolant fluid to the central inlet of the engine block. In this documentation, the vis-a-vis and the vis-a-vis are in a perpendicular position, allowing the cylinder to rotate and cool.

Such a mono-block coolant body is metallic, and can be made by machining a metal block, or by casting followed by a re-milling. In all cases, it is a complex part shape, leading to a high production cost. In addition, the necessary play between the viscous valve and the rough bore of the receiving engine cartridge introduces uncertainty in the final position of the coolant and in the position of the impact of the coolant jet on the piston bottom.

In addition, some leakage defects between the sprayer body and the engine crankcase wall were found, so that a portion of the coolant escapes directly between the sprayer body and the engine crankcase wall and does not reach the piston.

Other complex monoblock body forms of spray are described in US-A-2 991 769 and FR-A-2 259 981.

The first is the Piston Cooling Sprayer, which is a type of sprayer in which the sprayer body is held in place by a fastening plate fixed by screws through two holes in the plate.

The problem of the present invention is to design a new screw-valve sputter structure for piston cooling which can be constructed significantly less costly than known structures, while performing all the functions of centering and rotating locking for precise positioning of the sputter in the engine cylinder, and while increasing the orientation accuracy and reproducibility of the coolant jet projected onto the piston bottom.

The present invention is based on the observation that the piston cooling sputter body has a complex shape intended to perform multiple functions: some parts of the shape are intended to perform the functions of centering and rotating locking of the sputter body in the engine cylinder; other parts of the shape are intended to perform the function of conduction of the coolant and the sealing function between the sputter body and the engine crankcase wall, as well as the function of forming and directing the coolant jet.

For this purpose, a piston coolant jet for an internal combustion engine of the invention includes the characteristics of claim 1.

It is found that, unexpectedly, such a simplified structure of the sprayer attachment ensures effective solidisation of the sprayer in the cylinder casing, while improving positioning accuracy.

The outer surface of the sleeve is made of a straight- or cross-molded section.

However, it is more efficient and less expensive to provide a smooth outer surface for the sleeve.

In any case, it may be advantageous to provide at the base of the outer surface of the sleeve a slit limiting the length of the sleeve in contact with the wall of the fluid intake orifice, thus controlling the force required for the penetration of the spray and its extraction.

Other objects, features and advantages of the present invention will be shown by the following description of particular embodiments, in connection with the attached figures, including: Figure 1 is a cut-face view showing a cooling splash according to an embodiment of the invention; Figure 2 is a right-hand side view of the splash in Figure 1; Figure 3 is a top-side view of the splash in Figure 1; and Figure 4 is a cut-face half-view showing a cooling splash according to the invention associated with an engine cylinder in a particular piston embodiment.

In the embodiment shown in Figure 4, a piston coolant sprayer 1 is a part attached to the cylinder 2 crankcase wall inside the engine, designed to take coolant flowing through a coolant pipe 3 and to project the coolant into the engine cylinder against the bottom 4 of the piston 5 i.e. against the piston face which is outside the blast chamber 6.

Sprayer 1 comprises a sprayer body 7 drilled from an axial channel 8 communicating with a cross-drill 9 connected to a coolant outlet injection line 10.

The coolant outlet injection line 10 is an arc tube with one end 11 in the cross-sectional bore 9 of the sprayer body 7 and the other end 12 in the piston 5.

In Figure 4, piston 5 is shown in its extreme lower operating position, and the coolant jet is illustrated by the mixed line 13. The importance of a good orientation and concentration accuracy of the coolant jet 13 is understood, to strike piston 5 in an appropriate area that favors the distribution of the coolant on piston bottom 4, regardless of the position of piston 5 along its stroke.

It is therefore necessary to provide for means of centering and rotating locking of the sprayer body 7 on the cylinder 2 crankcase wall.

Figures 1 to 3 illustrate the sprinkler 1 in Figure 4 at a larger scale. According to the invention, the correct positioning of sprinkler 1 and jet 13 is ensured by using the coolant outlet injection line 10 itself as the reference, for this purpose, the coolant outlet injection line 10 comprises two opposite side faces of reference 18 and 19, as shown in Figure 3, made up of the side faces of a rectilinear portion 28 of the line 10 to be suitably conformed to constitute reference faces. These side faces of reference 19 18, 19 and 19 can cooperate with positioning buttresses 20 and 21 of one or two small rings, thus achieving the best possible performance during the sprinkler 10 times during the manufacture and positioning of the sprinkler 1 in the engine.

According to the invention, as shown in more detail in Figures 1 to 4, the sprinkler body 7 comprises a cylindrical 14-revolution sleeve, coaxial with the axial channel 8. The outer diameter of the sleeve 14 is suitable for its forced introduction into the fluid intake 15 of the cylinder cartridge 2. The fluid intake 15 is itself cylindrical-revolution.

In the illustrated method, the outer surface of sleeve 14 comprises a cut-off section 16, which may be an intermediate section along the L-length of sleeve 14.

Alternatively, the cutting section 16 may have a cross-cutting cutting as shown in Figure 2.

Alternatively, the outer surface of the sleeve 14 may comprise a smooth cylindrical 16 portion with tolerances for tight fit.

Alternatively, portion 16 of the outer surface of sleeve 14 may have a longitudinal or circular growth.

In any case, it may be advantageous to provide at the base of the outer surface of the sleeve 14 a ring-shaped gorge 22 which limits the length of the portion 16 of the outer surface of the sleeve in contact with the wall of the fluid inlet 15.

Thus, according to the invention, the body of the sprayer 7 has no other means of securing the sprayer to the cylinder casing 2 and securing its rotational locking around its axis.

It is noted that the adjustment of the sleeve 14 in the fluid intake hole 15 and its guidance by the positioning stoppers 20 and 21 improve the positioning accuracy of the sprinkler by the fact that no placement is left between the sleeve 14 and the fluid intake hole 15 and by the fact that the guidance is the same during the two final forming operations of the duct 10 and the insertion of the sprinkler 1 into the engine.

The end of sleeve 14 has a conical chamfer 17 designed to facilitate penetration into the fluid inlet hole 15, limiting the risk of degradation of the fluid inlet hole 15 wall and facilitating assembly.

The presence of the force 16 handles ensures a high mechanical rigidity of the sprinkler assembly in cylinder housing 2, while ensuring a sufficient seal to prevent coolant leakage between the handles 14 and the fluid intake housing 15.

An internal combustion engine may thus advantageously include coolant sprinklers 1 of the invention, as described above, fixed in the piston chamber (s) and fitted to each project the coolant into a concentrated jet on the bottom 4 of a piston 5.

The present invention is not limited to the embodiments which have been explicitly described, but includes the various variations and generalizations thereof contained in the claim field below.

Claims (8)

1. Spray nozzle (1) for cooling internal combustion engine pistons (5), comprising a spray nozzle body (7) with an axial passage (8) through it communicating with a transverse bore (9) connected to a cooling fluid outlet injection conduit (10), one end (11) of which is fastened into the transverse bore, the spray nozzle body (7) being shaped so that it can be fixed to the cylinder wall (2) and establish sealed communication between the axial passage (8) and a fluid feed orifice (15) for introducing the cooling fluid into the spray nozzle (1), with centering and rotation preventing means for positioning the spray nozzle body (7) in a cylinder of the engine, characterized in that:

   - the spray nozzle body (7) comprises a sleeve (14) in the shape of a cylinder of revolution, coaxial with the axial passage (8), the outside diameter of the sleeve (14) being such that it can be force-fitted into the fluid feed orifice (15) which is itself a cylinder of revolution,

   - the cooling fluid outlet injection conduit (10) has, directly adjacent to the spray nozzle body (7), a cylindrical rectilinear portion (28) of conduit with lateral faces which constitute two opposed lateral reference faces (18, 19), shaped to constitute reference faces that can cooperate with locating abutments both during bending of the conduit (10) and during fitting of the spray nozzle (1) into the engine.
2. Cooling spray nozzle according to claim 1, characterized in that the outside surface of the sleeve (14) has a knurled portion (16) with straight knurling.
3. Cooling spray nozzle according to claim 1, characterized in that the outside surface of the sleeve (14) has a knurled portion (16) with criss-cross knurling.
4. Cooling spray nozzle according to claim 1, characterized in that the outside surface of the sleeve (14) has a smooth cylindrical portion (16) with tolerances enabling a tight fit.
5. Cooling spray nozzle according to any one of claims 1 to 4, characterized in that the outside surface of the sleeve (14) has, at its base, an annular groove (22) limiting the length of the sleeve interengaged with the wall of the fluid inlet orifice (15).
6. Internal combustion engine comprising cooling spray nozzles (1) according to any one of claims 1 to 5, fixed into the piston chamber or chambers and each adapted to spray a concentrated jet of cooling fluid onto the back (4) of a piston (5).
7. Method of positioning a spray nozzle (1) for cooling internal combustion engine pistons (5), the spray nozzle (1) comprising a spray nozzle body (7) and a cooling fluid outlet injection conduit (10), method in which the cooling fluid outlet injection conduit (10) itself is used as positioning reference.
8. Method as claimed in claim 7, characterized in that the cooling fluid outlet injection conduit (10) comprises a cylindrical rectilinear portion (28) of conduit, adjacent to the spray nozzle body (7), having two opposed lateral reference faces (18, 19), and in that a fitting tool with locating abutments (20, 21) is used, which bear at the outlet of the conduit (10) against the lateral reference faces (18, 19) leaving a small minimum clearance.