CN110953085A

CN110953085A - Ductile iron piston and internal combustion engine

Info

Publication number: CN110953085A
Application number: CN201911163060.4A
Authority: CN
Inventors: 丛建臣; 吕世杰; 孙军; 冯梅珍; 王旭阳; 丛红日
Original assignee: Shandong University of Technology; Tianrun Crankshaft Co Ltd
Current assignee: Shandong University of Technology; Tianrun Crankshaft Co Ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2020-04-03

Abstract

The invention provides a ductile iron piston and an internal combustion engine, and relates to the technical field of internal combustion engines, the ductile iron piston is provided with an inner cavity, the bottom of the inner cavity is provided with a piston opening, the side wall of the inner cavity is provided with a side edge part, and the side edge part is used for increasing the area of the side wall of the inner cavity; the side edge part comprises a plurality of grooves arranged at intervals, and the grooves are communicated with the inner cavity. The ductile iron piston provided by the invention increases the area of the side wall of the inner cavity, relieves the technical problem of poor heat dissipation performance of the ductile iron piston in the prior art, and is further beneficial to improving the heat dissipation efficiency of the piston.

Description

Ductile iron piston and internal combustion engine

Technical Field

The invention relates to the technical field of internal combustion engines, in particular to a ductile iron piston and an internal combustion engine.

Background

The piston is used as a main component of an internal combustion engine, and bears the action of high temperature and high pressure during working and generates high-speed reciprocating motion. An excessive piston weight will be detrimental to the operational stability of the internal combustion engine. The aluminum alloy piston can reduce the weight of the piston due to the advantage of low density, but the aluminum piston cannot meet the strength requirement of the piston under the condition that the pressure is more than 20 MPa. In addition, because the piston expands due to heating, the expanded piston is easy to generate clamping stagnation when moving along the cylinder, and therefore how to radiate the heat of the piston becomes a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a ductile iron piston and an internal combustion engine, which are used for relieving the technical problem of poor heat dissipation performance of the piston in the prior art.

In a first aspect, the present invention provides a ductile iron piston, wherein the ductile iron piston is provided with an inner cavity; the lateral wall of inner chamber is equipped with side edge portion, side edge portion is used for increasing the area of inner chamber lateral wall.

With reference to the first aspect, the present disclosure provides a first possible implementation manner of the first aspect, wherein the side edge portion includes a plurality of grooves arranged at intervals, and each of the plurality of grooves is communicated with the inner cavity.

With reference to the first possible implementation manner of the first aspect, the present invention provides a second possible implementation manner of the first aspect, wherein a plurality of the grooves are arranged at intervals from one end near the bottom of the ductile iron piston to one end near the top of the ductile iron piston; the opening area of any one groove close to the top of the ductile iron piston is smaller than that of any one groove close to the bottom of the ductile iron piston.

With reference to the first aspect, the present disclosure provides a third possible implementation of the first aspect, wherein the inner cavity includes a connecting rod cavity and a cooling oil cavity, the cooling oil cavity being in fluid communication with the connecting rod cavity; the ductile iron piston comprises a head part and a skirt part connected with the head part; the skirt part is arranged in an enclosing manner to form the connecting rod cavity; the cooling oil chamber is disposed at the head portion.

With reference to the third possible implementation manner of the first aspect, the present invention provides a fourth possible implementation manner of the first aspect, wherein a side wall of the cooling oil chamber close to the axis of the ductile iron piston is inclined in a direction away from the axis of the ductile iron piston from an end communicating with the connecting rod chamber to an end away from the connecting rod chamber.

In combination with the third possible embodiment of the first aspect, the present disclosure provides a fifth possible embodiment of the first aspect, wherein the cooling oil chamber extends in a circumferential direction of the head portion; the cooling oil cavity is provided with an oil through hole, and the oil through hole is communicated with the connecting rod cavity in a fluid mode.

With reference to the fifth possible implementation manner of the first aspect, the present invention provides a sixth possible implementation manner of the first aspect, wherein the oil through port is connected to an oil blocking member, and the oil blocking member is configured to cover the oil through port to reduce an opening degree of the oil through port.

With reference to the sixth possible implementation manner of the first aspect, the present invention provides a seventh possible implementation manner of the first aspect, wherein a fastening piece is connected in the oil through opening, and the fastening piece abuts against a side of the oil blocking piece away from the cooling oil chamber.

With reference to the fifth possible implementation manner of the first aspect, the present invention provides an eighth possible implementation manner of the first aspect, wherein the oil through port includes: the first oil through opening and the second oil through opening; the first oil through opening and the second oil through opening are arranged at intervals along the circumferential direction of the head part, and the first oil through opening and the second oil through opening are respectively communicated with the fluid of the connecting rod cavity.

In a second aspect, the present invention provides an internal combustion engine comprising: the ball iron piston is inserted in the cylinder.

The embodiment of the invention has the following beneficial effects: adopt the ductile iron piston to be equipped with the inner chamber, the lateral wall of inner chamber is equipped with the mode of side portion of following, and the side portion of following is used for increasing the area of inner chamber lateral wall, makes fluid get into the inner chamber through the piston opening to the area of inner chamber lateral wall has been increased through side portion of following, thereby increased the area of contact of ductile iron piston with fluid, and then be favorable to improving ductile iron piston radiating efficiency.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a cross-sectional view of a ductile iron piston according to an embodiment of the present invention;

FIG. 2 is a front view of a ductile iron piston according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a bottom view of a ductile iron piston according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a ductile iron piston according to an embodiment of the present invention.

Icon: 001-head; 010-lumen; 101-a link cavity; 102-a cooling oil cavity; 1021-a first oil through opening; 1022-a second oil through port; 011-combustion chamber recess; 012-a recess; 013-annular grooves; 014-side groove; 020-side edge portion; 021-pin hole; 002-skirt portion; 003-oil blocking member; 031-a first oil-retaining disc; 032-second oil retaining disk; 004-a card fastener; 041-first circlip; 042-second circlip.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "physical quantity" in the formula, unless otherwise noted, is understood to mean a basic quantity of a basic unit of international system of units, or a derived quantity derived from a basic quantity by a mathematical operation such as multiplication, division, differentiation, or integration.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

As shown in fig. 1, the ductile iron piston provided in the embodiment of the present invention is provided with an inner cavity 010; the side wall of the inner cavity 010 is provided with a side edge portion 020, and the side edge portion 020 is used for increasing the area of the side wall of the inner cavity 010.

Specifically, the bottom of the inner cavity 010 has a piston opening for sleeving the connecting rod, thereby pivotally connecting the small end of the connecting rod in the inner cavity 010. When the ductile iron piston reciprocates along the cylinder, oil in the internal combustion engine flows through the piston opening under the stirring action of the crank connecting rod to enter the inner cavity 010, and the oil is contacted with the side wall of the inner cavity 010, so that the heat dissipation of the ductile iron piston is realized through the heat exchange between the ductile iron piston and the oil; or when the ductile iron piston moves to the bottom dead center, oil is injected into the inner cavity 010 through the piston opening through the oil injection nozzle, and the oil contacts the side wall of the inner cavity 010, so that heat of the ductile iron piston is absorbed.

In some embodiments, the side portion 020 includes a plurality of protruding blocks protruding towards the inner portion of the inner cavity 010, the plurality of protruding blocks are arranged at intervals, the plurality of protruding blocks and the ductile iron piston are integrally formed through a casting process, the surface area of the side wall of the inner cavity 010 is increased through the protruding blocks, the contact area of oil and the ductile iron piston is further increased, and therefore the heat dissipation efficiency of the ductile iron piston is improved.

In the embodiment of the present invention, the side portion 020 includes a plurality of grooves disposed at intervals, and the plurality of grooves are all communicated with the inner cavity 010. The groove comprises a pit with a circular or oval cross section, and the pit is communicated with the inner cavity 010; or, the recess includes a plurality of annular grooves that extend along ball iron piston circumference, and the annular groove communicates with inner chamber 010. The surface area of the side wall of the inner cavity 010 is increased through the grooves, and oil entering the inner cavity 010 splashes and flows into the pits, so that the oil and the ductile iron piston have a large heat exchange area, and the heat dissipation efficiency of the ductile iron piston is improved. In addition, the volume of the inner cavity 010 is increased through the groove, so that more oil can be contained in the inner cavity 010, and heat dissipation of the ductile iron piston is further facilitated. In addition, the side wall of the inner cavity 010 is provided with the groove, so that the wall thickness of the inner cavity 010 is reduced, and the weight of the ductile iron piston is reduced.

Furthermore, the ductile iron piston is cast by ductile cast iron, and the wear resistance is superior to that of a forged steel ductile iron piston; and the strength of the nodular cast iron is higher than that of the aluminum alloy, so that the nodular cast iron piston can be applied to an internal combustion engine with the pressure of more than 20 MPa.

As shown in fig. 1, 2 and 3, a plurality of grooves are arranged at intervals from one end close to the bottom of the ductile iron piston to one end close to the top of the ductile iron piston; the opening area of any groove close to the top of the ductile iron piston is smaller than that of any groove close to the bottom of the ductile iron piston.

Specifically, the grooves are configured as dimples, and the radial dimension of any dimple near the top of the ductile iron piston is less than the radial dimension of any dimple near the bottom of the ductile iron piston. A combustion chamber is formed between the top of the ductile iron piston and the cylinder, so that the structural strength required by the top of the ductile iron piston is high, and the radial size of a pit close to the top of the ductile iron piston is small, so that the structural strength of the ductile iron piston is prevented from being insufficient. In addition, the ductile iron piston is cast, and the radial size of a pit at the top of the ductile iron piston is smaller than that of a pit close to the bottom of the ductile iron piston, so that the die is conveniently pulled out from the opening of the piston when the die is opened.

Further, the inner cavity 010 includes a link cavity 101 and a cooling oil cavity 102, and the cooling oil cavity 102 is in fluid communication with the link cavity 101; the ductile iron piston comprises a head 001 and a skirt section 002 connected with the head 001; the skirt section 002 is encircled to form a connecting rod cavity 101; the cooling oil chamber 102 is provided at the head 001. Wherein, the side edge portion 020 is arranged on the side wall of the cooling oil cavity 102, the skirt portion 002 is provided with a pin hole 021, the small end of the connecting rod is inserted in the connecting rod cavity 101, and the ductile iron piston pin passes through the pin hole 021 and the connecting rod, so that the connecting rod is pivoted in the connecting rod cavity 101. When the ductile iron piston reciprocates along the axial direction of the cylinder, the connecting rod swings around the ductile iron piston pin in a reciprocating mode, the connecting rod stirs oil, and therefore the oil flows into the cooling oil cavity 102 from the connecting rod cavity 101; alternatively, when the ductile iron piston moves to the bottom dead center, oil is injected into the cooling oil chamber 102 through the piston opening by the oil injection nozzle.

Further, from the end communicating with the connecting rod cavity 101 to the end away from the connecting rod cavity 101, the side wall of the cooling oil cavity 102 close to the axis of the ductile iron piston is inclined away from the axis of the ductile iron piston.

Specifically, the side wall of the cooling oil cavity 102 close to the axis of the ductile iron piston is inclined, so that the width dimension of the cooling oil cavity 102 is gradually reduced from one end close to the bottom of the ductile iron piston to one end close to the top of the ductile iron piston, and the mold is conveniently pulled out of the cooling oil cavity 102 during mold opening. In addition, the top of the ductile iron piston is provided with a combustion chamber groove 011, and the side wall of the cooling oil cavity 102 close to the axis of the ductile iron piston from the end close to the bottom of the ductile iron piston to the end close to the top of the ductile iron piston inclines towards the direction departing from the combustion chamber groove 011, so that the wall thickness between the cooling oil cavity 102 and the combustion chamber groove 011 is uniform, and the problem of uneven expansion with heat and contraction with cold caused by uneven wall thickness is avoided. That is, the wall thickness between the combustion chamber and the cooling oil chamber 102 is uniform, thereby facilitating uniform transfer of heat in the combustion chamber to the oil in the cooling oil chamber 102.

Further, the head 001 is provided with a depressed part 012 towards one side of the connecting rod cavity 101, the combustion chamber groove 011 surrounds the depressed part 012 along the circumference of the ball iron piston, thereby increasing the area of the top of the ball iron piston, and the depressed part 012 recesses the top of the ball iron piston to make the wall thickness of the top of the ball iron piston approach to uniform distribution.

As shown in fig. 5, the tip of the head 001 is provided with a plurality of side grooves 014 communicating with the combustion chamber groove 011, and the side grooves 014 are provided at intervals in the circumferential direction of the ductile iron piston. One end of the side groove 014 extends and is communicated with the combustion chamber groove 011, and the side groove 014 penetrates through the side wall of the ductile iron piston, so that the wall thickness of the top of the ductile iron piston is further reduced, and the surface area of the top of the ductile iron piston is increased. A space for avoiding the valve is formed by the side groove 014 and the combustion chamber groove 011, so that the tappet is prevented from impacting the ductile iron piston when the valve is opened.

As shown in fig. 1, 3, and 4, the cooling oil chamber 102 extends in the circumferential direction of the head portion 001; the cooling oil cavity 102 is provided with an oil through opening which is in fluid communication with the connecting rod cavity 101.

Specifically, the cross section of the cooling oil cavity 102 is annular, that is, the cooling oil cavity 102 surrounds the combustion chamber groove 011, and oil entering the cooling oil cavity 102 can flow along the circumferential direction of the ductile iron piston, so that the cooling of all positions in the circumferential direction of the ductile iron piston is realized. In the compression stroke of the internal combustion engine, the ductile iron piston moves away from the crankshaft, and oil in the cooling oil cavity 102 flows through the oil port and the connecting rod cavity 101 under the action of inertia and is discharged through the piston opening; in the power stroke of the internal combustion engine, the ductile iron piston moves towards the direction close to the crankshaft, and the crankshaft rotates to stir oil to flow through the piston opening, the connecting rod cavity 101 and the oil through opening and enter the cooling oil cavity 102; alternatively, when the ductile iron piston moves to the bottom dead center, oil is injected into the cooling oil chamber 102 through the piston opening by the oil injection nozzle. The top of the ductile iron piston is heated in the fuel combustion process, and the temperature of oil entering the cooling oil cavity 102 is lower than that of the top of the ductile iron piston, so that the heat of the ductile iron piston can be transferred to the oil in the cooling oil cavity 102, and the cooling effect on the ductile iron piston is realized.

Further, the oil passing port is connected with an oil blocking piece 003, and the oil blocking piece 003 is used for covering the oil passing port to reduce the opening of the oil passing port. Wherein, fender oil spare 003 configuration is to baffle or dog, keeps off oil spare 003 and is connected to the oil feed-through mouth through welding or buckle to thereby realize sheltering from the part of oil feed-through mouth through keeping off oil spare 003, and then reduce the open area who leads to the oil feed-through mouth, slow down the outflow speed of fluid in the cooling oil pocket 102 from this, and then prolong the heat exchange time of fluid and ductile iron piston.

Further, a clamping piece 004 is connected in the oil through hole, and the clamping piece 004 abuts against one side of the oil blocking piece 003 departing from the cooling oil cavity 102.

Specifically, the ductile iron piston is provided with a clamping groove, the clamping piece 004 is connected in the clamping groove, and the clamping piece 004 abuts against one side of the oil blocking piece 003 departing from the cooling oil cavity 102, so that the oil blocking piece 003 is fixed through the clamping piece 004. For example: the clamping piece 004 is configured to be an elastic retainer ring, and the clamping groove is formed in the side wall of the oil through hole. When the elastic retainer ring is inserted into the clamping groove, the elastic retainer ring abuts against the end face of the oil blocking piece 003 departing from the cooling oil cavity 102, so that the oil blocking piece 003 can be prevented from falling off. In addition, the area of the oil blocking member 003 is smaller than the opening area of the oil passage opening, so that the oil blocking member 003 can only partially block the oil passage opening, so that oil can flow into and out of the cooling oil chamber 102 through the non-shielded region of the oil passage opening.

Further, lead to the oil mouth and include: a first oil through port 1021 and a second oil through port 1022; the first oil through port 1021 and the second oil through port 1022 are arranged at intervals along the circumferential direction of the head 001, and the first oil through port 1021 and the second oil through port 1022 are respectively in fluid communication with the link cavity 101.

Specifically, the first oil through port 1021 and the second oil through port 1022 are centrosymmetric with respect to the axis of the ball iron piston, in other words, the first oil through port 1021 and the second oil through port 1022 are symmetrically arranged with respect to the axis of the pin hole 021, so that the weight of the ball iron piston is symmetrically distributed with respect to the axis of the pin hole 021, and further, in the reciprocating motion process of the ball iron piston, the center of mass of the ball iron piston, the moving direction line of the ball iron piston and the axis of the pin hole 021 are all located in the same plane, so that the eccentric friction of the ball iron piston on the inner wall of the cylinder due to the increase of the center of mass deflection can be avoided.

Further, the oil blocking member 003 includes a first oil blocking disc 031 and a second oil blocking disc 032, and the locking member 004 includes a first elastic retaining ring 041 and a second elastic retaining ring 042. The first oil blocking disc 031 covers the first oil through port 1021, the first elastic retainer ring 041 is connected in the first oil through port 1021, and the first elastic retainer ring 041 abuts against the end face, away from the cooling oil cavity 102, of the first oil blocking disc 031; the second oil blocking disk 032 covers the second oil through opening 1022, the second elastic check ring 042 is connected in the second oil through opening 1022, and the second elastic check ring 042 abuts against an end surface of the second oil blocking disk 032, which is away from the cooling oil cavity 102. The first oil blocking disc 031 blocks part of the first oil through port 1021, and a first oil opening is formed between the first oil blocking disc 031 and the first oil through port 1021; the second oil blocking disk 032 partially blocks the second oil through hole 1022, and a second oil opening is formed between the second oil blocking disk 032 and the second oil through hole 1022. The first oil opening and the second oil opening are symmetrical relative to the axis center of the ductile iron piston, and the central angle corresponding to the circular arc between the first oil opening and the second oil opening along the circumferential direction of the ductile iron piston is 180 degrees, so that the weight of the ductile iron piston on two sides of the axis of the pinhole 021 is balanced.

As shown in fig. 2, an annular groove 013 is provided on an outer side wall of the head 001, and the annular groove 013 extends in a circumferential direction of the ductile iron piston. The annular grooves 013 are provided in plurality, and the plurality of annular grooves 013 are arranged at intervals along the axial direction of the ductile iron piston. An oil ring or an air ring can be matched and connected in the annular groove 013, so that the sealing performance between the ductile iron piston and the cylinder wall is improved.

Example two

As shown in fig. 1, an internal combustion engine according to an embodiment of the present invention includes: the cylinder and the ductile iron piston provided by the first embodiment are inserted into the cylinder. Specifically, when the internal combustion engine works, the heat of fuel combustion is transferred to the head 001 of the ductile iron piston, and the crank connecting rod has a stirring effect on oil in a crank cavity of the internal combustion engine and enables the oil to flow into the cooling oil cavity 102; alternatively, when the ductile iron piston moves to the bottom dead center, oil is injected into the cooling oil chamber 102 through the piston opening by the oil injection nozzle. Under the action of the side edge portion 020, the contact area of the oil and the inner wall of the cooling oil cavity 102 is increased, and therefore the heat dissipation efficiency of the ductile iron piston is improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ductile iron piston characterized in that it is provided with an inner cavity (010);

the lateral wall of inner chamber (010) is equipped with side portion (020), side portion (020) is used for increasing the area of inner chamber (010) lateral wall.

2. A ductile iron piston according to claim 1 wherein the side edge portion (020) comprises a plurality of spaced grooves, and wherein each of the plurality of grooves is in communication with the inner cavity (010).

3. The ductile iron piston of claim 2 wherein a plurality of said grooves are spaced from an end proximate a bottom of said ductile iron piston to an end proximate a top of said ductile iron piston;

the opening area of any one groove close to the top of the ductile iron piston is smaller than that of any one groove close to the bottom of the ductile iron piston.

4. The ductile iron piston of claim 1 wherein the inner cavity (010) comprises a connecting rod cavity (101) and a cooling oil cavity (102), the cooling oil cavity (102) being in fluid communication with the connecting rod cavity (101);

the ductile iron piston comprises a head (001) and a skirt (002) connecting the head (001);

the skirt (002) is arranged in a surrounding mode to form the connecting rod cavity (101);

the cooling oil chamber (102) is provided in the head portion (001).

5. The ductile iron piston of claim 4, wherein a side wall of the cooling oil chamber (102) near the axis of the ductile iron piston is inclined away from the axis of the ductile iron piston from an end communicating with the connecting rod chamber (101) to an end facing away from the connecting rod chamber (101).

6. The ductile iron piston of claim 4 wherein said cooling gallery (102) extends circumferentially of said head (001);

the cooling oil cavity (102) is provided with an oil through hole, and the oil through hole is communicated with the connecting rod cavity (101) in a fluid mode.

7. The ductile iron piston according to claim 6, wherein the oil passing port is connected with an oil blocking member (003), and the oil blocking member (003) is used for covering the oil passing port to reduce the opening degree of the oil passing port.

8. The ductile iron piston according to claim 7, wherein a fastener (004) is connected in the oil through hole, and the fastener (004) abuts against a side of the oil blocking member (003) away from the cooling oil cavity (102).

9. The ductile iron piston of claim 6, wherein the oil through port comprises: a first oil through opening (1021) and a second oil through opening (1022);

the first oil through hole (1021) and the second oil through hole (1022) are arranged at intervals along the circumferential direction of the head (001), and the first oil through hole (1021) and the second oil through hole (1022) are respectively communicated with the connecting rod cavity (101) in a fluid mode.

10. An internal combustion engine, comprising: a cylinder and a ductile iron piston according to any one of claims 1-9 inserted in said cylinder.