FR2719868A1 - Piston cooling nozzle for internal combustion engine. - Google Patents

Abstract

The nozzle according to the invention comprises a nozzle body (7) produced by integral assembly of a generally cylindrical ring (22) comprising an axial bore (10) and a transverse bore (11) and a transverse plate (23) comprising a peripheral surface (30) shaped to fit on corresponding faces of the cylinder housing wall on which the nozzle body (7) is fixed. The nozzle body (7) is fixed by a valve screw. A bent tube (12) forms a coolant outlet injection pipe, its first end (19) being attached in the transverse bore (11) of the ring (22). The nozzle body (7) is thus produced at a lower cost, and makes it possible to project a precise and concentrated jet of cooling fluid onto the bottom of a piston of an internal combustion engine.

Description

I

  PISTON COOLING JET FOR A MOTOR

INTERNAL COMBUSTION

  Piston cooling jets for internal combustion engines are used to spray coolant such as oil against the piston bottom, i.e.

  against the piston face outside the explosion chamber.

  The piston cooling nozzles usually used are attachments, fixed to the crankcase and communicating with a coolant supply orifice. The position of the nozzle must be precisely determined, to precisely determine the impact of the jet of coolant on the bottom

piston.

  A known technique consists in providing a one-piece nozzle body, limited by a bearing face and by an opposite fixing face, provided with an axial bore intended to be traversed by a screw-flap for supplying fluid and fixing . The axial hole communicates with a transverse hole connected to a coolant outlet injection pipe. The valve screw is shaped and adapted to hold the nozzle body in abutment by its bearing face against the peripheral zone of a fluid supply orifice formed in the wall of the crankcase, and to transmit the coolant. at the entrance of the transverse hole. Centering and rotation blocking means

  allow the nozzle body to be positioned in the engine cylinder.

  Such a one-piece cooling nozzle body is metallic, and can be produced by machining a metal block, or by molding followed by repeat machining. In all cases, it is a complex form of part, leading to a high production cost. In addition, the accuracy of the coolant jet is proven

  insufficient, the fluid jet obtained being relatively divergent.

  In addition, certain leaks have been observed between the nozzle body and the crankcase wall, so that a portion of the coolant escapes directly between the

  nozzle and the crankcase wall, and does not reach the piston.

  The problem proposed by the present invention is to design a new piston cooling nozzle structure which can be produced by a less expensive method than the machining of a metal block of complex shape, while fulfilling all the functions centering and locking in rotation for precise positioning of the nozzle in the engine cylinder, and while increasing the precision and concentration of the jet of cooling fluid projected on the piston bottom. The present invention results from the observation that the piston cooling nozzle body has a complex shape intended to perform multiple functions: certain shaped parts are intended to fulfill the functions of centering and blocking the rotation of the nozzle body in the engine cylinder; other shaped parts are intended to fulfill the function of conduction of the coolant and the seal function between the nozzle body and the crankcase wall, as well as the function of formation and direction of the jet of coolant cooling. The idea is to produce separately, on the one hand, the form portions intended to fulfill the functions of centering and rotation blocking, on the other hand, the form portions ensuring the functions of fluid conduction and sealing, and possibly the shape portions ensuring the training function

  and direction of the coolant jet.

  For this, a piston cooling nozzle for an internal combustion engine according to the invention comprises a nozzle body bounded by a bearing face and by an opposite fixing face and provided with an axial bore intended to be traversed by a screw for fluid supply and fixing valve, the axial hole communicating with a transverse hole connected to a coolant outlet injection pipe, the screw valve being shaped and adapted to keep the nozzle body in support by its bearing face against the peripheral zone of a fluid inlet port for the cylinder block wall and for transmitting the coolant to the inlet of the transverse bore, with means of centering and locking in rotation to position the nozzle body in the engine cylinder; the nozzle body is produced by integral assembly of a generally cylindrical ring comprising the axial bore and the transverse bore, and a transverse plate comprising the centering and locking means

in rotation.

  According to an advantageous embodiment, the transverse plate has a circular fixing hole which fits by fitting onto a corresponding circular surface of the ring. The transverse plate

  can advantageously be brazed on the circular ring surface.

  To increase the seal, it is advantageous to provide a shoulder, limiting the circular bearing surface of the ring, and forming a stop against which the plate comes to bear. The thickness of the plate can then be less than the height of the circular surface between the bearing face and the shoulder, so that the nozzle body is in abutment against the cylinder block wall by a body portion sprinkler in the shape of an annular lip ensuring a reinforced seal around

the fluid supply orifice.

  To improve the concentration of the coolant jet, the coolant outlet injection duct is advantageously a curved tube, one end of which is attached in the transverse bore of the ring, and possibly brazed in the transverse bore of Ring. It appears that the jet precision obtained by bending a tube is much better than the precision obtained by machining a metal block. This improvement is probably due to the fact that, in the bent tube, the flow

of fluid remains laminar.

  Other objects, features and advantages of this

  invention will become apparent from the following description of embodiments

  particular, made in relation to the attached figures, among which: - Figure 1 is a half side view in section showing a cooling nozzle according to the invention associated with a driving cylinder in a first embodiment of the piston; - Figure 2 is a half side view in section showing a cooling nozzle according to the invention associated with a driving cylinder in a second embodiment of piston, and in a second embodiment of the nozzle body according to invention; - Figure 3 is a bottom view of the assembly of Figure 1, in a first embodiment of the nozzle body according to the invention; - Figure 4 is a bottom view of the assembly of Figure 2 in a second embodiment of the nozzle body according to the present invention; - Figure 5 is a bottom view of the nozzle body of Figure 3; and - Figure 6 is a front view in cross section along the plane A-A

in Figure 5.

  As illustrated in FIGS. 1 and 2, a piston cooling nozzle 1 is an attached piece on the cylinder crankcase wall 2, inside the engine, configured to take coolant circulating in a cooling pipe 3 and to project the coolant into the engine cylinder against the bottom 4 of the piston 5, that is to say against the face of the piston which is

  outside the explosion chamber 6.

  The nozzle 1 comprises a nozzle body 7, limited by a bearing face 8 and by a fixing face 9 opposite the bearing face. The nozzle body 7 is provided with an axial bore 10 communicating with a transverse bore 11 connected to an outlet injection pipe of

coolant 12.

  A valve screw 13, comprising a threaded rod 14 and a head, holds the nozzle body 7. The threaded rod 14 of the screw valve 13 passes through the axial bore 10 of the nozzle body 7, and is screwed into an orifice of fluid 16 formed in the wall of cylinder casing 2 and communicating with the cooling pipe 3. The head 15 of the valve screw 13 comes to bear against the fixing face 9 of the nozzle body 7, in order to maintain the body of nozzle 7 supported by its bearing face 8 against the peripheral zone of the fluid supply orifice 16

cylinder housing wall 2.

  The screw-valve 13 has an axial bore 17 in which is housed a pressure-sensitive shutter valve, suitable for transmitting the coolant when its pressure in the coolant pipe 3 is greater than a predetermined value, and for closing off the axial bore 17 when the pressure of

  coolant is less than said predetermined pressure.

  At the outlet of the valve, the cooling fluid escapes radially from the axial bore 17 through lateral holes such as the hole 18, to penetrate into the nozzle body 7 and exit through the axial bore 10 and

  the outlet injection pipe 12.

  The coolant outlet injection pipe 12 is a curved tube, one end 19 of which is fitted into the transverse bore 11 of the nozzle body 7, and the other end of which is directed towards the piston 5. In the figures 1 and 2, the piston 5 is shown in its two extreme operating positions, and the cooling fluid jet is illustrated by the dashed line 21. We understand the advantage of good orientation accuracy and concentration of the jet 21 of coolant, to strike the piston 5 in a suitable zone favoring the distribution of the coolant on the bottom 4 of the piston, whatever the position of the piston 5 along its stroke. It is therefore necessary to provide means for centering and blocking the rotation of the nozzle body 7 on the housing wall.

cylinder 2.

  According to the invention, as illustrated in more detail in Figures and 6, the nozzle body 7 is produced by integral assembly of a generally cylindrical ring 22, comprising the axial bore 10 and the transverse bore 11, and a plate transverse 23 comprising the centering and locking means in rotation. The end 19 of the curved tube forming the outlet injection duct 12 is attached in the transverse bore 11 of the ring 22, and can advantageously be brazed

in this transverse hole 11.

  The transverse plate 23 has a circular fixing hole 24 fitting by fitting onto a corresponding circular surface 25 of the ring 22. The transverse plate 23 can advantageously be brazed on the circular surface 25 of the ring, or

united by any other means.

  In the embodiment shown, the circular bearing surface 25 of the ring is limited by a shoulder 26 forming a stop against which the transverse plate 23 comes to bear. The thickness E of the transverse plate 23 is advantageously less than the height H of the circular bearing 25 between the bearing face 8 and the shoulder 26. In this way, the nozzle body 7 comes to bear against the cylinder casing wall 2 by a portion of nozzle body 7 in the form of an annular lip 27, ensuring a reinforced seal around the orifice

fluid supply 16.

  The axial bore 10 of the ring 22 advantageously comprises a part with a larger cross section 28 and a part with a reduced section 29. The part with a larger cross section 28 forms a

  coolant distribution chamber around the screw

  valve 13, opposite the transverse bore 11 of the ring 22 and opposite the lateral holes 18 of the screw-valve 13. The reduced section portion 29 has guide faces to form a transverse support between

the valve screw 13 and the ring 22.

  In the embodiment illustrated in FIGS. 1, 3, and 6, the means for centering and blocking in rotation the nozzle body 7 on the wall of cylinder housing 2 are formed by the peripheral surface of the transverse plate 23. For this, the transverse plate 23 is shaped according to a contour suitably adapted to the corresponding contour of a housing 31 formed in the wall of cylinder casing 2 and in which the transverse plate 23 is inserted. In the embodiment shown, the transverse plate 23 carries on the faces

  side of the housing 31 by the two facets 32 and 33.

  In the embodiment illustrated in FIGS. 2 and 4, the means for centering and blocking the rotation of the nozzle body 7 further comprise an off-center axial pin 34, protruding from one face of the transverse plate 23, and coming from engage in a hole

  corresponding 35 of the cylinder block wall 2.

  It will be noted, in FIG. 2, a particular embodiment of the piston 5, comprising a gallery 36 for the passage of cooling fluid inside the piston 5 itself. It is also understood, in this embodiment, the advantage to provide a particularly precise and concentrated coolant jet, making it possible to inject all of the coolant inside the

  gallery 36, even when the piston is distant from the injection pipe 12.

  An internal combustion engine can thus advantageously comprise cooling nozzles 1 according to the invention, as described above, fixed in the piston chamber or chambers and adapted to each project the cooling fluid in a jet.

  concentrated on the bottom 4 of a piston 5.

  The present invention is not limited to the embodiments which have been explicitly described, but it includes the various thereof.

  variants and generalizations contained in the field of claims

below.

Claims (11)

  1 - Nozzle (1) for cooling the piston (5) for an internal combustion engine, comprising a nozzle body (7) bounded by a support face (8) and by a fixing face (9) opposite and provided with '' an axial bore (10) intended to be traversed by a screw-valve (13) for supplying fluid and for fixing, the axial bore (10) communicating with a transverse bore (11) connected to an injection pipe of coolant outlet (12), the valve screw (13) being shaped and adapted to keep the nozzle body (7) in abutment by its bearing face (8) against the peripheral zone of an orifice fluid supply (16) from the cylinder block wall (2) and for transmitting the coolant to the inlet of the transverse bore (11), with means for centering and locking in rotation for positioning the nozzle body ( 7) in the engine cylinder, characterized in that the nozzle body (7) is produced by integral assembly of a ring (22) -generally cylindrical comprising the axial bore (10) and the transverse bore (11), and of a transverse plate (23) comprising the centering and locking means in rotation.   2 - Sprinkler according to claim 1, characterized in that the transverse plate (23) has a circular hole (24) for fixing which fits by fitting onto a corresponding circular surface (25) of the ring (22).   3 - Sprinkler according to claim 2, characterized in that the transverse plate (23) is also brazed on the circular surface (25) of ring.   4 - Sprinkler according to one of claims 2 or 3, characterized   in that the circular bearing surface (25) of the ring is limited by a shoulder (26) forming a stop against which the plate comes to bear transverse (23).   5 - Sprinkler according to claim 4, characterized in that the thickness (E) of the transverse plate (23) is less than the height (H) of the circular surface (25) between the bearing face (8) and the shoulder (26), so that the nozzle body (7) bears against the cylinder casing wall (2) by a portion of the nozzle body in the form of an annular lip (27), ensuring a seal   reinforced around the fluid supply orifice (16).   6 - nozzle according to any one of claims 1 to 5,   characterized in that the coolant outlet injection pipe (12) is a bent tube, one end (19) of which is   reported in the transverse bore (11) of the ring (22).   7 - Nozzle according to claim 6, characterized in that the attached end (19) of the coolant outlet injection pipe (12) is also brazed in the transverse bore (11) of ring.   8 - Sprinkler according to any one of claims 1 to 7,   characterized in that the axial bore (10) of the ring (22) comprises: - a part with a larger cross section (28), forming a coolant distribution chamber around the screw-valve (13) and facing of the transverse bore (11), - a reduced section (29) comprising guide faces for   constitute a transverse support between the valve screw (13) and the ring (22).   9 - nozzle according to any one of claims 1 to 8,   characterized in that the means for centering and blocking the rotation of the nozzle body (7) are formed by the peripheral surface (30) of the transverse plate (23).   10 - Sprinkler according to any one of claims 1 to 9,   characterized in that the means for centering and for blocking the rotation of the nozzle body (7) comprise an axial pin (34) which is offset and protrudes from one side of the transverse plate (23) and which engages   in a corresponding hole (35) in the cylinder block wall (2).   11 - Internal combustion engine comprising spray nozzles   cooling (1) according to any one of claims 1 to 10,   fixed in the piston chamber (s) and adapted to each project the coolant in a concentrated jet on the bottom (4) of a piston (5).