CN104126068B - Piston cooling device - Google Patents

Abstract

Cooling device for the reciprocating-piston (2) of explosive motor includes the cooling medium injector (5 for being used to be ejected into cooling oil in the space (10) positioned at the lower section of piston top (2a) and between piston (2) and cylinder sleeve (1), 5 '), for by cooling oil from positioned at piston top (2a) lower section space (10) introduce cooling oil passage (7) opening (8), and for cooling oil to be supplied into cooling medium injector (5,5 ') cooling medium pipeline (6,6 ').Cooling medium injector (5,5 ') in such height placement in cylinder, i.e., the height is caused, when piston (2) is positioned at bottom dead centre, the top (5a, 5a ') of cooling medium injector (5,5 ') is located at the top of the central axis (4a) of the piston pin (4) of piston (2).

Description

Piston cooling device

technical field

The invention relates to a cooling device for a reciprocating piston of an internal combustion engine. The invention also relates to a cylinder liner for a piston engine.

Background technique

In large medium speed engines, piston cooling is typically performed by drilling holes in the crankshaft, connecting rods and piston pins. In high speed engines, piston cooling is usually performed using oil injection. Ejection cooling is also advantageous in medium speed engines as it omits the need for oil drilling in the crank gear components and thus allows higher loads and lower manufacturing costs. In a typical jet cooling arrangement, the cooling arrangement is provided with a separate lubricating oil system for piston cooling. Oil injection nozzles for atomizing cooling oil are arranged in the engine block. Via spray nozzles, oil is sprayed onto the underside of each piston. The piston skirt is provided with a space for receiving oil. Bores in the oil receiving space lead to cooling channels in the piston crown. A disadvantage of this piston cooling device is that the injection distance is relatively long, which has a detrimental effect on the function of the cooling system. Cooling was also a challenge to implement because of the limited space within the engine block and especially below the cylinders due to the moving connecting rods and counterweights.

Contents of the invention

The object of the present invention is to provide a cooling device for reciprocating pistons of an internal combustion engine. A piston is disposed within a cylinder liner of the engine and includes a crown and a skirt. Another object of the present invention is to provide an improved cylinder liner for a piston engine.

The cooling device according to the invention comprises a cooling oil channel arranged at least partially in the piston crown, a coolant injector for injecting cooling oil into the space located below the piston crown and between the piston and the cylinder liner, the arrangement On the bottom surface of the cooling oil passage are openings for introducing cooling oil from a space below the piston crown to the cooling oil passage, and cooling medium pipes for supplying cooling oil to the cooling medium injector. The coolant injector is arranged in the cylinder at a height such that, when the piston is at bottom dead center, the top end of the coolant injector is above the central axis of the piston pin of the piston.

Since the cooling medium sprayer is arranged close to the bottom surface of the cooling oil passage, the spraying distance is short and the cooling effect of the cooling oil is improved.

According to the embodiment of the present invention, when the piston is at the bottom dead center, the top end of the injector is above the entire piston pin.

According to a further embodiment of the invention, the piston is a box-shaped piston, wherein the piston skirt is open in the direction of the plug pin. According to a further embodiment of the invention, the coolant injector is arranged protruding into the cylinder in the direction of the piston pin. In the case of a box piston, the coolant injector may be fastened directly to the cylinder liner and positioned close to the bottom surface of the cooling oil passage.

According to an embodiment of the invention, a part of the coolant injector is arranged in the wall of the cylinder liner parallel to the longitudinal axis of the cylinder liner. According to another embodiment of the invention, the lower end surface of the cylinder liner is provided with openings for introducing cooling oil into the cooling medium duct located in the wall of the cylinder liner. According to another embodiment of the invention, the device comprises a bore in the engine block for introducing cooling oil into the cooling medium duct located in the wall of the cylinder liner. If the cooling medium duct is arranged in the wall of the cylinder liner, the need for a separate pipe can be omitted. By arranging bore holes in the lower radial support of the cylinder liner, the cooling oil can also serve as a damping medium for reducing wear and corrosion of the contact surfaces between the engine block and the cylinder liner.

According to an embodiment of the invention, the outer surface of the cylinder liner is provided with openings arranged opposite the bearing surface of the engine block for introducing cooling oil into the cooling medium duct. According to another embodiment of the invention, the bearing surface of the engine block is arranged to support the lower end of the cylinder liner in radial direction.

According to yet another embodiment of the invention, the device comprises a clearance between the engine block and the cylinder liner, from which clearance the cooling oil is introduced into the cooling medium injector. The cooling oil can thus also serve as a damping and cooling medium for the cylinder liner. Therefore, effective cooling of the cylinder liner can be achieved, and due to the damping effect, wear and corrosion between the engine block and the cylinder liner are also reduced.

The cylinder liner according to the present invention includes a cooling medium duct arranged in the wall of the cylinder liner and a cooling medium duct arranged on the inner surface of the cylinder liner and in fluid communication with the cooling medium duct to supply cooling oil to the cooling medium injector and further to the engine Piston opening. The outer surface of the cylinder liner is provided with openings for introducing cooling oil into the cooling medium duct, the openings may be disposed opposite to a surface disposed in the engine block to support a lower end of the cylinder liner in a radial direction.

In the case of the cylinder liner according to the invention, cooling oil can be introduced via the lower end of the cylinder liner into a cooling medium injector positioned close to the piston crown.

According to an embodiment of the invention, the opening on the inner surface of the cylinder liner is located at such a height that, when the piston is at bottom dead center, the tip of the coolant injector can be arranged on the central axis of the piston pin of the piston above.

According to an embodiment of the invention, at least a part of the cooling medium duct in the wall of the cylinder liner is parallel to the longitudinal axis of the cylinder liner.

Description of drawings

Fig. 1 shows a piston cooling device according to an embodiment of the present invention.

Fig. 2 shows a cross-sectional view of Fig. 1 along the line A-A.

Fig. 3 shows a piston cooling device according to another embodiment of the present invention.

Fig. 4 shows a piston cooling device according to yet another embodiment of the present invention.

detailed description

Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

FIG. 1 shows a cooling device for a reciprocating piston 2 of an internal combustion engine according to an embodiment of the invention. In Fig. 1, the piston 2 is located at the bottom dead center. Engines using piston cooling are large medium or high speed internal combustion engines. The engine can be used, for example, as the main or auxiliary engine in a boat or in a power plant for generating electric power. The engine may have any reasonable number of cylinders, which may, for example, be arranged in an inline or V configuration. Each cylinder of the engine is provided with a cylinder liner 1 . The cylinder liner 1 is arranged in an engine block 12 . The upper end of the cylinder liner 1 is provided with a collar 1 which leans against the upper surface of the engine block 12 . The engine block 12 includes a protrusion 19 extending towards the longitudinal axis of the cylinder liner 1 and supporting the upper end of the cylinder liner 1 in the radial direction. The second protrusion 13 forms a radial support for supporting the lower end of the cylinder liner 1 in the radial direction. Piston 2 is arranged inside the cylinder. The piston includes a piston crown 2a and a piston skirt 2b. Piston 2 is connected to connecting rod 3 via piston pin 4 . The piston 2 is a so-called box piston, wherein the piston skirt 2 b is open in the direction of the piston pin 4 . Therefore, at both ends of the piston pin 4, an empty space 10 is formed between the cylinder liner 1 and the piston 2 and below the piston crown 2a.

In order to cool the piston 2, the engine is provided with a cooling device. The cooling device serves to introduce cooling oil onto the bottom surface of the piston 2 and further into a cooling oil channel 7 arranged at the upper end of the piston 2 and at least partially in the piston crown 2a. The cooling device includes a coolant injector 5 arranged inside the cylinder. A cooling pump (not shown) is connected to the cooling medium injector 5 with a cooling medium pipe 6 for supplying cooling oil to the cooling medium injector 5 . The coolant injector 5 is located at such a height in the cylinder that the tip 5a of the coolant injector 5 is located above the central axis of the piston pin 4 when the piston 2 is at the bottom dead center. In the embodiment of FIG. 1 , the top end 5 a of the coolant injector 5 is located above the entire piston pin 4 . Since the cooling medium injector 5 is positioned close to the lower surface of the cooling oil passage 7, a short spray distance and efficient cooling are achieved. Cooling oil is sprayed into a space 10 located below the piston crown 2 a and between the cylinder liner 1 and the piston 2 . The cooling medium sprayer 5 is arranged to spray cooling oil toward the upper part of the piston 2 . From the space 10 below the piston crown 2 a, cooling oil can flow into the cooling oil channel 7 through the opening 8 arranged in the bottom of the cooling oil channel 7 .

In the embodiment of FIG. 1 , the coolant duct 6 is arranged partially within the wall of the cylinder liner 1 . Using this arrangement, the need for separate plumbing can be reduced. Coolant injectors 5 are arranged protruding from the wall of the cylinder liner 1 into the cylinder in the direction of the piston pin 4 . However, it is also possible that the coolant injector 5 protrudes into the cylinder at a different angle. The coolant injector 5 can also be offset from the center line of the piston pin 4 . The coolant injector 5 is L-shaped, and the open end of the coolant injector 5 faces the cylinder head. The cooling oil spray is thus directed towards the lower surface of the cooling oil channel 7 . The lower end of the cylinder liner 1 is provided with an opening 9 for introducing cooling oil into the cooling medium pipe 6 located in the wall of the cylinder liner 1 . The opening 9 is located on the end face of the cylinder liner 1 .

In Figures 1 and 2, a second cooling medium injector 5' is also shown. The second cooling medium duct 6' is arranged partly in the wall of the cylinder liner 1 for connecting the second cooling medium injector 5' to the cooling oil pump. Cooling oil is introduced into the second cooling medium duct 6 ′ in the wall of the cylinder liner 1 via the bore hole 11 in the lower radial support 13 of the cylinder liner 1 . The cylinder liner 1 is provided with an opening 17 arranged on the outer surface of the cylinder liner 1 . The opening 17 is arranged to face the surface of the engine block which supports the lower end of the cylinder liner 1 in the radial direction. The opening 17 is aligned with the bore 11 of the engine block 12 . A seal 21 is arranged between the cylinder liner 1 and the engine block 12 around the opening 17 . Through the opening 17 cooling oil can be introduced into the cooling medium duct 6 ′ in the wall of the cylinder liner 1 . By arranging the borehole 11 in the protrusion 13 supporting the cylinder liner 1 , the cooling oil can also be used as a damping medium for reducing wear and corrosion of the contact surfaces between the engine block 12 and the cylinder liner 1 . The inner surface of the cylinder liner 1 is provided with openings 20, which are in fluid communication with the cooling medium ducts 6, 6'. Through the opening 20 cooling oil can be supplied to the cooling medium injector 5'. The opening 20 is at such a height that the tip 5a' of the coolant injector 5' can be arranged above the central axis 4a of the piston pin 4 when the piston 2 is at bottom dead center. Although two different cooling arrangements are shown in FIG. 1 , each cylinder of the engine is preferably provided with the same cooling arrangement at both ends of the piston pin 4 .

In the embodiment of FIG. 3 , the cooling medium duct 6 for introducing the cooling oil into the cooling medium injector 5 is partially arranged inside the engine block 12 . Cooling oil is introduced in the coolant line 6 into the recess 14 between the engine block 12 and the cylinder liner 1 . The cylinder liner 1 is provided with bore holes 16 for introducing cooling oil from a clearance 14 between the engine block 12 and the cylinder liner 1 to the cooling medium injector 5 . By arranging the supply of cooling oil via the clearance 14 between the engine block 12 and the cylinder liner 1, the cooling oil can also be used as a damper for reducing wear and corrosion of the contact surfaces between the engine block 12 and the cylinder liner 1. shock medium. This arrangement also enables effective cooling of the cylinder liner 1 . The embodiment of FIG. 4 is similar to the embodiment of FIG. 3 . The difference is that the cooling oil is introduced into the volume 14 via the upper end of the volume 14 between the engine block 12 and the cylinder liner 1 . A separate pipe piece 15 is used to introduce cooling oil into the coolant line 6 of the engine block 12 .

It will be appreciated by a person skilled in the art that the invention is not limited to the embodiments described above but that changes may be made within the scope of the application. For example, features of different implementations may be combined.

Claims (9)

1. a kind of cooling device of reciprocating-piston (2) for explosive motor, the piston (2) is arranged in the engine In cylinder sleeve (1) and including piston top (2a) and piston skirt (2b), the cooling device includes：

- cooling oil passage (7), the cooling oil passage is at least partially disposed in the piston top (2a),

- cooling medium injector (5,5'), the cooling medium injector is used to for cooling oil spurts to be extremely located at the piston top In the lower section of (2a) and the space (10) between the piston (2) and the cylinder sleeve (1), the cooling medium injection Device (5,5') is in such height placement in cylinder, i.e. the height is caused, described when the piston (2) is positioned at bottom dead centre The top (5a, 5a') of cooling medium injector (5,5') is located at the central axis (4a) of the piston pin (4) of the piston (2) Top,

- opening (8), the opening is arranged on the basal surface of the cooling oil passage (7), for by cooling oil from positioned at the work The space (10) of the lower section of plug top (2a) introduces the cooling oil passage (7), and

- cooling medium pipeline (6,6'), the cooling medium pipeline be used for by cooling oil supplied to the cooling medium injector (5, 5'),

Characterized in that, described device includes the allowance (14) being located between engine body (12) and the cylinder sleeve (1), it is cold But oil introduces the cooling medium injector (5) from the allowance (14).

2. device according to claim 1, it is characterised in that when the piston (2) is positioned at bottom dead centre, the cooling is situated between The top (5a, 5a') of matter injector (5,5') is located at the top of the whole piston pin (4).

3. device according to claim 1 and 2, it is characterised in that the piston (2) is box-type piston (2), wherein, institute Piston skirt (2b) is stated to be opened wide towards the direction of the piston pin (4).

4. device according to claim 3, it is characterised in that the cooling medium injector (5,5') is arranged to along described The direction of piston pin (4) is projected into the cylinder.

5. device according to claim 1, it is characterised in that a part for the cooling medium pipeline (6,6') with institute The mode for stating the longitudinal axis parallel of cylinder sleeve (1) is arranged in the wall of the cylinder sleeve (1).

6. device according to claim 5, it is characterised in that the rear surface of the cylinder sleeve (1) is provided with opening (9), cooling oil is introduced the cooling medium pipeline (6) in the wall of the cylinder sleeve (1).

7. device according to claim 5, it is characterised in that described device includes the brill in engine body (12) Hole (11), the drilling is for cooling oil to be introduced the cooling medium pipeline in the wall of the cylinder sleeve (1) (6').

8. device according to claim 7, it is characterised in that be provided with opening on the outer surface of the cylinder sleeve (1) (17), the opening (17) is arranged against the supporting surface of the engine body (12) for cooling oil is introduced into described Cooling medium pipeline is (6').

9. device according to claim 8, it is characterised in that the supporting surface arrangement of the engine body (12) Radially to support the lower end of the cylinder sleeve (1).