CN110894813A

CN110894813A - Cylinder liner, method of manufacturing the same, and method of manufacturing cylinder block using the same

Info

Publication number: CN110894813A
Application number: CN201810977382.1A
Authority: CN
Inventors: 佐藤阳; 田山公一
Original assignee: TPR Co Ltd; TPR Industry Co Ltd
Current assignee: TPR Co Ltd; TPR Industry Co Ltd
Priority date: 2018-08-22
Filing date: 2018-08-22
Publication date: 2020-03-20
Anticipated expiration: 2038-08-22
Also published as: CN110894813B

Abstract

The present invention provides a cylinder liner and a method of manufacturing the cylinder liner, characterized in that a plurality of projections are integrally distributed on an outer circumferential surface of the cylinder liner, and the outer circumferential surface of the cylinder liner has surface-worked portions extending downward by a predetermined length from an upper end surface along an axial direction of the cylinder liner at two diametrically opposite sides of the cylinder liner, the surface-worked portions being located radially inward with respect to the outer circumferential surface of the cylinder liner. The invention also provides a manufacturing method of the cylinder block applying the cylinder sleeve.

Description

Cylinder liner, method of manufacturing the same, and method of manufacturing cylinder block using the same

Technical Field

The present invention relates to a cylinder liner, and in particular, to a cylinder liner for insert casting (insert casting) used in a cylinder block, a manufacturing method of the cylinder liner, and a manufacturing method of a cylinder block using the cylinder liner.

Background

A cylinder block with a cylinder liner for an engine has been used in practical applications, and the cylinder liner is generally applied to a cylinder block made of an aluminum alloy (aluminum-silicon alloy, etc.).

With the increasing importance of the country on the conditions of air pollution and the like generated in the automobile field, stricter requirements on energy conservation and emission reduction are put forward on the engine, so that the realization of lighter weight of the engine is an important measure for dealing with energy conservation and emission reduction at present, and the realization of lighter weight of the cylinder sleeve is beneficial to the realization of lighter weight of the engine. Therefore, how to achieve the lightweight of the cylinder liner becomes a problem to be solved urgently by those skilled in the art.

The effect of reducing the fuel consumption of the engine in light weight can be realized by reducing the cylinder center distance or the weight of the cylinder sleeve.

Disclosure of Invention

In view of the above objects, the present invention provides a cylinder liner having an outer peripheral surface with surface-worked portions extending a predetermined length in an axial direction at diametrically opposite sides, and a method of manufacturing the cylinder liner, in which interference between a body of the cylinder liner and a flow path through which coolant flows is prevented because the surface-worked portions are radially inwardly indented by a distance at an axially upper portion as compared to the outer peripheral surface, so that the flow path passes between the cylinder liners without cutting the cylinder liner, which reduces the difficulty of machining, and saves the manufacturing cost and time.

Further, due to the presence of the surface processed portion, it is not necessary to separate adjacent cylinder liners by a predetermined distance in order to avoid interference between the outer periphery of the cylinder liner and the flow path, so that the interval (cylinder center distance) between the adjacent cylinder liners can be reduced as much as possible, thereby reducing the size and weight of the entire engine.

Further, the size of the surface processed portion is formed to be as small as possible, so that the processing of the protruding portion of the outer peripheral surface can be reduced as much as possible while avoiding the aforementioned interference, and therefore the surface bonding strength of the outer periphery of the cylinder liner 1 and the insert casting material can be maintained as much as possible.

The present invention also provides a manufacturing method of a cylinder block using the cylinder liner, by which the cylinder liner can be positioned in a straight line with a simple operation and surface processed portions of adjacent cylinder liners are opposed to each other.

According to a first aspect of the present invention, there is provided a cylinder liner characterized in that,

a plurality of protrusions are integrally distributed on the outer circumferential surface of the cylinder liner, and

the outer circumferential surface of the cylinder liner has, at diametrically opposite sides of the cylinder liner, surface-worked portions that extend downward from an upper end surface along an axial direction of the cylinder liner by a predetermined length, the surface-worked portions being located radially inward with respect to the outer circumferential surface of the cylinder liner.

Further, the predetermined length over which the surface processed portion extends is 10mm or more and 40mm or less, and a recessed depth of the surface processed portion in a radial direction with respect to an outer peripheral surface of the cylinder liner is 0.3mm or more and 2.0mm or less.

Further, the cylinder liner has a sprayed layer.

Further, a portion of the cylinder liner having the surface processed portion is covered with a sprayed layer formed of a sprayed material.

Further, the upper portion of the cylinder liner is covered with a sprayed layer formed of a spray material along the entire circumferential direction.

Further, the entire outer circumferential surface of the cylinder liner is covered with a sprayed layer formed of a spray material.

Further, the spraying material is aluminum, aluminum-silicon alloy, aluminum alloy or iron alloy.

Further, the sprayed layer is composed of a first sprayed layer covering an upper portion of the outer circumferential surface of the cylinder liner and a second sprayed layer covering a lower portion of the outer circumferential surface of the cylinder liner, and

the thermal conductivity of the first sprayed layer is higher than the thermal conductivity of the second sprayed layer.

Further, the spraying material forming the first spraying layer is aluminum, aluminum-silicon alloy, aluminum alloy or iron alloy.

Further, the cylinder liner has at least one positioning portion.

Further, the position of the positioning portion is associated with the position of the surface finished portion, so that the position of the surface finished portion can be determined using the position of the positioning portion.

Further, the positioning portion is located at a lower end of the cylinder liner.

Further, the positioning portion and a circumferential intermediate position of at least one of the surface processed portions form a predetermined angle in the circumferential direction, and the predetermined angle is any angle in a range of 0 ° or more and 90 ° or less.

Further, the positioning portion has a notch shape in a plan view.

Further, the positioning portion has a rectangular shape, an arc shape, a triangular shape, or a trapezoidal shape in a plan view.

According to a second aspect of the present invention, there is provided a manufacturing method of a cylinder block including the cylinder liner in the first aspect, the method including:

a cylinder liner positioning step of fitting at least a portion of the cylinder liner with a cylinder liner fitting portion provided in a mold to position the cylinder liner in a straight line and to cause the surface processed portions of adjacent ones of the cylinder liners to oppose each other;

a cylinder block casting step of casting a body of the cylinder block for the plurality of positioned cylinder liners; and

a flow path forming step of forming a flow path of a coolant in a space formed by the surface processed portions of the adjacent cylinder liners in the body of the cylinder block after casting.

Further, in the cylinder liner positioning step, the positioning portions of the plurality of cylinder liners are brought into contact with a linear positioning shaft to position the plurality of cylinder liners on a predetermined straight line.

According to a third aspect of the present invention, there is provided a manufacturing method of a cylinder liner, the method including:

a cylinder liner casting step of casting a cylinder liner, the outer circumferential surface of which is integrally distributed with a plurality of projections;

a machining-site setting step of setting a machining reference surface on a main body of the cylinder liner, and setting machining sites where surface machined portions are to be formed, at an upper portion of an outer circumferential surface of the cylinder liner, in accordance with the machining reference surface, so that the machining sites are located at diametrically opposite sides of the cylinder liner; and

a surface processed portion forming step of performing cutting processing on an outer circumferential surface of the cylinder liner at the processing site to form a surface processed portion such that the surface processed portion extends downward by a predetermined length in an axial direction of the cylinder liner from an upper end surface of the cylinder liner, and the surface processed portion is located radially inward with respect to the outer circumferential surface of the cylinder liner.

Further, the manufacturing method of the cylinder liner further includes:

a positioning portion forming step of forming, at a lower end of the cylinder liner, a positioning portion whose position is associated with the surface processed portion so that the position of the surface processed portion can be determined by the position of the positioning portion.

Further, the positioning portion and a circumferential intermediate position of the surface processed portion are circumferentially aligned with each other.

Further, the manufacturing method of the cylinder liner further includes:

and a spray coating forming step of spraying the outer circumferential surface of the cylinder liner to form a spray coating.

Further, at least a portion of the cylinder liner having the surface finished portion is covered with the sprayed layer.

The technical solutions of the present invention will be described in further detail below with reference to the drawings and preferred embodiments of the present invention, and the advantageous effects of the present invention will be further apparent.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention.

Fig. 1 is a schematic view of an engine to which a cylinder liner according to the present invention is applied.

Fig. 2 is a perspective view of a cylinder liner according to a first embodiment of the present invention.

Fig. 3 is a cross-sectional view of the cylinder liner according to the first embodiment of the present invention, taken along line III-III in fig. 2.

Fig. 4 is an enlarged, upper partial view of the cross-sectional view shown in fig. 3.

Fig. 5 is a sectional view taken along line I-I in fig. 1.

Fig. 6 is a perspective view of a cylinder liner according to a second embodiment of the present invention.

Fig. 7 is a perspective view of a first example of a cylinder liner according to a third embodiment of the present invention.

Fig. 8 is a perspective view of a second example of the cylinder liner according to the third embodiment of the present invention.

Fig. 9 is a perspective view of a third example of the cylinder liner according to the third embodiment of the present invention.

Fig. 10 is a perspective view of a fourth example of the cylinder liner according to the third embodiment of the present invention.

Fig. 11 is an explanatory view for setting a machining portion of the manufacturing method of the cylinder liner according to the present invention.

Fig. 12 is another explanatory view for setting a machining site of the manufacturing method of the cylinder liner according to the present invention.

Fig. 13 is a flowchart of a manufacturing method of a cylinder liner according to the present invention.

Fig. 14 is a flowchart of a manufacturing method of a cylinder block using the cylinder liner according to the present invention.

Fig. 15 is a schematic view showing the periphery of the flow path of the cylinder liner according to the present invention.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are only a few of the presently preferred embodiments of the invention, and not all embodiments. 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.

First, the basic configuration of an engine 11 to which the cylinder liner 1 according to the present invention is applied will be described with reference to fig. 1.

< Structure of Engine >

As shown in fig. 1, fig. 1 is a perspective view of an engine 11 to which a cylinder liner 1 according to the present invention is applied.

The engine 11 includes a cylinder block 13 and a cylinder head 12. The cylinder block 13 includes a plurality of cylinders 14, and each cylinder 14 includes one cylinder liner 1. An inner peripheral surface of each cylinder liner 1 (see fig. 2, an inner peripheral surface 21 of the cylinder liner 1) forms an inner wall of the cylinder 14, and the inner peripheral surface 21 of each cylinder liner 1 defines a cylinder bore 23 (see fig. 2) for the piston.

By insert casting the casting material, the outer peripheral surface (see fig. 2, outer peripheral surface 22) of each cylinder liner 1 is in contact with the cylinder block 13. The cylinder block 13 can be manufactured using a known engine insert casting material, for example, an aluminum alloy, an aluminum-silicon alloy, or the like.

As shown in fig. 1, a side of the cylinder liner 1 remote from the cylinder head 12 is defined as a lower side, and a side of the cylinder liner 1 close to the cylinder head 12 is defined as an upper side. Similarly, a portion of the cylinder liner 1 away from the cylinder head 12 is defined as a lower portion, and a portion of the cylinder liner 1 close to the cylinder head 12 is defined as an upper portion.

< Structure of Cylinder liner >

The outer circumferential surface of the cylinder liner has a plurality of protrusions distributed thereon, and the outer circumferential surface of the cylinder liner has, at diametrically opposite sides of the cylinder liner, surface-worked portions that extend downward from an upper end surface along an axial direction of the cylinder liner by a predetermined length, the surface-worked portions being located radially inward with respect to the outer circumferential surface of the cylinder liner.

Preferably, the cylinder liner further has a sprayed layer.

Preferably, the cylinder liner further has at least one positioning portion.

The specific structure of each embodiment of the cylinder liner 1 according to the present invention will be described below with reference to fig. 2 to 10.

< first embodiment >

First, a specific structure of a cylinder liner 1 according to a first embodiment of the present invention will be described with reference to fig. 2 to 5.

Fig. 2 is a perspective view of a cylinder liner according to a first embodiment of the present invention. Fig. 3 is a cross-sectional view of the cylinder liner according to the first embodiment of the present invention, taken along line III-III in fig. 2. Fig. 4 is an enlarged, upper partial view of the cross-sectional view shown in fig. 3. Fig. 5 is a sectional view taken along line I-I in fig. 1. The line I-I is a straight line connecting the axes of the adjacent cylinder liners 1.

As shown in fig. 3, the cylinder liner 1 of the present embodiment is formed in a substantially cylindrical shape, and the outer circumferential surface 22 of the cylinder liner 1 is integrally formed with a plurality of projections 3 (see an enlarged view of fig. 3), the plurality of projections 3 being randomly formed on the outer circumferential surface of the cylinder liner, the projections being casting projections formed at the time of casting to increase the surface bonding strength of the cylinder liner 1 with the insert casting material. The partially enlarged sectional view in fig. 3 is only one example of the shape of the protruding portion, and the shape of the protruding portion is not limited thereto, and may be, for example, a triangular protrusion, a cylindrical protrusion, or other irregular protrusion shapes, or the like.

The cylinder liner 1 according to the first embodiment of the present invention has surface processed portions 2 at diametrically opposite sides, and the surface processed portions 2 extend downward in the axial direction from the upper end along the axial direction of the cylinder liner 1 by a predetermined length L (see fig. 4), preferably 10mm or more and 40mm or less.

This surface processed portion 2 may be formed by removing a part of the protrusion 3 of the cylinder liner 1 by cutting so that arc-shaped surfaces at axially upper portions at diametrically opposite sides of the outer circumferential surface 22 are processed into flat surfaces of a substantially rectangular shape, so that the surface processed portion 2 is located radially inward with respect to the outer circumferential surface 22 of the cylinder liner 1.

As shown in fig. 4, the recess depth h of the surface finished part 2 in the radial direction with respect to the outer circumferential surface 22 of the cylinder liner 1 is 0.3mm or more and 2mm or less, and the difference (length a in fig. 3) between the radial width (wall thickness) of the cylinder liner 1 and the recess depth h is 1mm or more to secure the strength of the cylinder liner at the surface finished part.

When the first embodiment according to the present invention is applied to the engine 11 as shown in fig. 1, the surface processed portions 2 of the adjacent cylinder liners 1 are opposed to each other, so that a space S is formed between the adjacent cylinder liners 1 due to the surface processed portions 2 as shown in fig. 5.

< action of the surface-treated component 2 >

In the engine 11 shown in fig. 1, the flow path P of the coolant passes between the adjacent cylinders 14, so that in the engine 11 to which the cylinder liner 1 of the present embodiment is applied, the flow path P passes through the space S between the mutually opposed surface processed portions 2 of the adjacent cylinder liners 1.

Therefore, in the present embodiment, the flow path P can be formed without interfering with the outer periphery of the cylinder liner 1 due to the presence of the surface processed portion 2, so that the flow path P is formed without cutting the cylinder liner 1, which reduces the difficulty of processing, and saves manufacturing cost and time, while also preventing the coolant from leaking from the boundary portion when interfering with the cylinder liner protrusion portion.

Further, due to the presence of the surface processed portion 2, it is not necessary to separate adjacent cylinder liners 1 by a predetermined distance in order to avoid interference between the outer periphery of the cylinder liner 1 and the flow path P, and thus the interval (cylinder center distance) between the adjacent cylinder liners can be reduced as much as possible, thereby reducing the size and weight of the entire engine.

Further, in the present embodiment, in order to avoid interference between the cylinder liner 1 and the flow path P, only a small portion of the outer circumferential surface is subjected to surface processing so that the size of the surface processed portion is as small as possible, and thus the processing of the protruding portion 3 of the outer circumferential surface can be reduced as much as possible while avoiding the aforementioned interference, and therefore the surface bonding strength between the outer circumference of the cylinder liner 1 and the insert casting material can be maintained as much as possible.

< second embodiment >

Fig. 6 shows a cylinder liner 1 according to a second embodiment of the present invention, which differs from the first embodiment only in that the cylinder liner 1 further has a positioning portion 4. Also, in the present embodiment, the same or similar components are given the same reference numerals, and the description of the same portions as those of the first embodiment in the present embodiment will be omitted.

As shown in fig. 6, the cylinder liner 1 also has a positioning portion 4, and the positioning portion 4 has a notch shape.

As shown in fig. 6, the positioning portion 4 is formed as a portion for positioning the surface processed portion 2, making it difficult to quickly and accurately determine the position of the surface processed portion 2 in the circumferential direction because the surface processed portion 2 is formed at diametrically opposite sides in the outer circumferential surface 22. Therefore, by correlating the position of the positioning portion 4 with the position of the surface processed portion 2, it is possible to easily and quickly determine the position of the surface processed portion 2 by the positioning portion 4 to ensure that the surface processed portions 2 of the adjacent cylinder liners 1 are opposed to each other when the cylinder liners 1 are applied.

The position of the positioning portion 4 may be aligned in the circumferential direction with a substantially middle position in the circumferential direction of the surface processed portion 2 at either side. And the position of the positioning portion 4 may be offset by a predetermined angle in the circumferential direction with respect to the substantially middle position in the circumferential direction of the surface processed portion 2 at either side. The predetermined angle may be any angle in the range of 0 ° to 90 ° as long as it can easily and quickly determine the position of the surface processed portion 2 by the positioning portion 4.

The number of the positioning portions 4 is not limited to 1 as shown in fig. 6, and may be a plurality of, for example, two positioning portions 4 opposed to each other in the radial direction, or four positioning portions 4 having an included angle of 90 ° between any two of them, or the like.

Further, it is preferable that the positioning portion 4 is located at the lower end of the cylinder liner 1 as shown in fig. 6.

Further, the notch shape of the positioning portion 4 is not limited to the rectangular shape in the plan view shown in fig. 6, and it may also be an arc shape, a triangular shape, a trapezoidal shape, or the like as long as it has a positioning function.

In addition to the above-described effects, the cylinder liner 1 in the second embodiment can also achieve the same actions and effects as those of the foregoing first embodiment.

< third embodiment >

Fig. 7 to 10 show a cylinder liner 1 according to a third embodiment of the present invention, which differs from the first and second embodiments only in that the cylinder liner 1 further has a sprayed layer 5. Also, in the present embodiment, the same or similar components are given the same reference numerals, and the description of the same portions as those of the first embodiment in the present embodiment will be omitted.

The sprayed layer 5 is formed by spraying a spray material, which may be aluminum, an aluminum alloy, an aluminum-silicon alloy, iron, an iron alloy, or the like. Among them, preferably, an aluminum-silicon alloy containing 12% Si (silicon) content may be used so that the composition of the spray material is the same as the material forming the cylinder block 13.

In addition, since different spray materials have different properties, for example, iron and aluminum do not differ much in adhesion and thermal conductivity, and aluminum has a cost advantage over aluminum-silicon alloys. Therefore, any of the above-described spray materials may be selected according to the production environment and the specific requirements.

Moreover, the thickness of the sprayed layer 5 is set to achieve this effect: when the cylinder liner 1 is cast using the casting material of the cylinder block 13, the anchoring effect by the protruding portion 3 is obtained by flowing the casting material of the cylinder block 13 into the recessed hole portion.

Fig. 7 to 10 show first to fourth examples of a cylinder liner 1 according to a third embodiment of the present invention. In the cylinder liner 1 according to the third embodiment of the invention, the sprayed layer 5 is formed so as to cover at least the surface processed portion 2.

As shown in fig. 7, the sprayed layer 5 is formed so as to cover a portion of the outer circumferential surface 22 of the cylinder liner 1 where the surface processed portion 2 is formed, that is, a portion (a substantially rectangular shaped flat surface) of the cylinder liner 1 extending downward by a predetermined length L from an upper end at both sides opposed to each other in the radial direction, so as to be able to cover at least the surface processed portion 2.

As shown in fig. 8, the sprayed layer 5 may also be formed to cover the upper portion of the outer peripheral surface 22 of the cylinder liner 1 along the entire circumference. Thereby improving the cooling property (heat radiation property) at the upper portion of the cylinder liner 1.

Further, as shown in fig. 9, the sprayed layer 5 can also be formed to cover the entire outer circumferential surface 22 of the cylinder liner 1. By forming the sprayed layer 5 so as to cover the entire outer peripheral surface 22, the bonding strength between the cylinder liner 1 and the cylinder block 13 is maximized, and the overall heat radiation performance is improved, so that the usability of the engine can be further improved.

Also, in addition to covering the entire outer peripheral surface 22 with the same material as shown in fig. 9, different spray materials may be used for the upper and lower portions as shown in fig. 10 to form the spray layer 51 and the spray layer 52, wherein the upper spray layer 51 covers the upper half of the outer peripheral surface 22 of the cylinder liner 1, the lower spray layer 52 covers the lower half of the outer peripheral surface 22 of the cylinder liner 1, and the thermal conductivity of the spray layer 51 is higher than that of the spray layer 52, and in the case where the spray layer is composed of the upper spray layer 51 and the lower spray layer 52, it is preferable that the spray material forming the upper spray layer 51 is aluminum, an aluminum alloy, an aluminum-silicon alloy, iron, an iron alloy, or the like.

During use of the engine 11, since the lower portion of the cylinder liner 1 is less affected by the combustion gas and the upper portion of the cylinder liner 1 is more affected by the combustion gas, resulting in a higher temperature of the upper portion of the cylinder liner 1 than the lower portion, the temperature difference during this process may cause deformation of the cylinder liner 1 to increase friction with the piston.

However, in the present embodiment, since the sprayed layer 5 is formed only at the upper portion, or the thermal conductivity of the sprayed layer 51 of the upper portion is made stronger than that of the sprayed layer 52 of the lower portion, the heat loss of the upper portion of the cylinder liner 1 is greater than that of the lower portion of the cylinder liner 1, thereby lowering the temperature of the upper portion, reducing the temperature difference between the upper and lower temperatures, and further suppressing deformation of the cylinder liner to reduce friction with the piston.

The structure of the cylinder liner 1 in the second embodiment is adopted in fig. 7 to 10, but not limited thereto, and the first embodiment and any structure that is modified or changed to the first and second embodiments may also be adopted.

Forming the sprayed layer 5 (or 51 and 52) on the outer circumferential surface of the cylinder liner 1 can enhance the bonding strength between the cylinder liner 1 and the cylinder block 13 and improve heat radiation. Further, the cylinder liner 1 in the third embodiment is also capable of achieving the same actions and effects as those of the foregoing first and second embodiments.

< method for manufacturing cylinder liner >

Hereinafter, a manufacturing method of manufacturing the cylinder liner having the configuration in the above-described embodiment will be described with reference to fig. 11 to 15.

The manufacturing method of a cylinder liner according to the present invention includes a protrusion forming step, a processed portion setting step, and a surface processed portion forming step.

Preferably, the manufacturing method of a cylinder liner according to the present invention further includes a pilot portion forming step.

Preferably, the manufacturing method of the cylinder liner according to the present invention further includes a spray coating layer forming step.

Step S101, a cylinder sleeve casting step: the cylinder liner is cast to form a cylinder liner having a plurality of protrusions integrally distributed on an outer circumferential surface thereof.

Specifically, for example, diatomaceous earth having an average particle diameter of 0.002 to 0.02mm, bentonite (binder), water, and a surfactant are mixed in a predetermined ratio to prepare a coating agent. The coating agent is sprayed on the inner surface of a mold (die) heated to 200 and 400 ℃ in a rotating state to form a coating layer on the inner surface of the die, the coating layer having a thickness of, for example, 0.5 to 1.1 mm. Under the action of the surfactant, steam bubbles generated in the coating form a plurality of concave holes on the coating. After the coating has dried, cast iron is poured into the rotating mold. At this time, the concave hole of the coating layer is filled with molten metal, and a plurality of protrusions 3 are formed. After the molten metal solidifies to form the cylinder liner 1, the coating is taken out of the mold together with the cylinder liner 1. The coating agent is removed by, for example, shot blasting, thereby manufacturing the basic configuration of the cylinder liner 1 having a plurality of projections 3 on the outer circumferential surface thereof. Through the above casting process, the plurality of projections 3 are randomly formed on the outer circumferential surface 22 of the substantially cylindrical cylinder liner 1, so that the entire area of the outer surface of the cylinder liner 1 can be increased.

Step S102, a machining site setting step of setting a machining reference plane on a basic configuration of the cylinder liner, and setting machining sites where surface machined portions are to be formed at an upper portion of an outer circumferential surface of the cylinder liner in accordance with the machining reference plane so as to be located at diametrically opposite sides of the cylinder liner.

Specifically, an end portion of the cylinder liner 1 where the surface processed portion 2 is to be formed is defined as an upper end, and an end portion opposite to the surface processed portion 2 is defined as a lower end, and the lower end of the cylinder liner 1 is cut into a machining reference plane. On the machining reference plane, any straight line passing through the axial center of the cylinder liner 1 is defined as a machining reference line, for example, a straight line (broken line) L1 shown in fig. 11. Subsequently, at the upper end of the cylinder liner 1, a straight line parallel to the machining reference line passing through the axial center of the cylinder liner 1, for example, a straight line (broken line) L2 parallel to a straight line L1 shown in fig. 11, is defined. That is, when the straight line L1 and the straight line L2 overlap each other in the plan view of the cylinder liner 1, the cut portion of the finished surface portion 2 can be specified.

By the above-described setting procedure, it is determined that the upper end portions a1, a2 of the cylinder liner 1 through which the straight line L2 passes are the processed portions where the surface processed portion 2 is to be formed at the upper portion of the outer circumferential surface 22 of the cylinder liner 1, the upper end portions a1, a2 at the diametrically opposite sides of the cylinder liner 1. Preferably, the plane of the surface processed portion 2 is perpendicular to the straight line L2.

For example, the straight line where the machining site of the surface machining section 2 is located is not necessarily parallel to the straight line L1, but may be at a predetermined angle α with respect to the straight line L1, and the size of the angle α may be set as necessary, preferably, 0 ° ≦ α ≦ 90 °. for example, as shown in fig. 12, the straight line (broken line) L3 is perpendicular to the straight line L2 and thus to the straight line L1, in which case, upper end portions a1 'and a 2' through which the straight line L3 passes may be employed as the forming portions of the surface machining section, at which time the machining site of the surface machining section 2 is perpendicular to the machining reference line L1 (α is 90 °).

Step S103, a surface processed portion forming step of performing cutting processing on an outer circumferential surface of the cylinder liner at the processing site to form a surface processed portion such that the surface processed portion extends downward by a predetermined length in an axial direction of the cylinder liner from an upper surface of the cylinder liner and the surface processed portion is located radially inward with respect to the outer circumferential surface of the cylinder liner.

Specifically, the outer circumferential surface 22 of the cylinder liner 1 is subjected to cutting processing at the processing site determined in step S102 by cutting processing means such as turning, milling, or the like to cut the plurality of projections 3 at the processing site, thereby processing the arc-shaped surface at the processing site into a substantially rectangular flat surface to form the surface processed portion 2. As shown in fig. 4, the surface processed portion 2 may be formed to extend a predetermined length L (i.e., a side length L of a rectangle) downward in the axial direction from the upper end in the axial direction of the cylinder liner 1, preferably, the predetermined length L is 10mm or more and 40mm or less. And as shown in fig. 4, the recess depth h of the surface finished part 2 in the radial direction with respect to the outer circumferential surface 22 of the cylinder liner 1 is preferably 0.3mm or more and 2mm or less, and the difference (length a in fig. 3) between the radial width (wall thickness) of the cylinder liner 1 and the recess depth h is 1mm or more to secure the strength of the cylinder liner at the surface finished part.

The manufacturing method of the cylinder liner according to the present invention further includes a locatable portion forming step S104. The positioning portion forming step will be specifically described below.

In the positioning portion forming step, at the lower end of the cylinder liner, a positioning portion whose position is associated with the surface processed portion is formed so that the position of the surface processed portion can be determined by the position of the positioning portion.

Specifically, as described in step S102, the machining reference line L1 on the machining reference plane passes through the points B1, B2 at the lower end of the cylinder liner 1, so that the sites B1, B2 can be set as the formation sites of the positioning portions. At the formation site of this positioning portion, the body of the cylinder liner is subjected to cutting work in the radial direction (from the outer peripheral surface to the inner peripheral surface), thereby forming a positioning portion 4 having a notch shape.

Through the above process, the positioning portions 4 are at the predetermined angle α with the surface processed portion 2, for example, α is 0 ° when the processing portions are a1, a2, at which time the positions of the positioning portions 4 and the substantially middle position in the circumferential direction of the surface processed portion 2 are aligned with each other in the circumferential direction, α is 90 ° when the processing portions are a1 ', a 2', that is, the positions of the positioning portions 4 are shifted by the predetermined angle α of 90 ° in the circumferential direction from the substantially middle position in the circumferential direction of the surface processed portion 2, whereby the positions of the surface processed portion 2 can be determined according to the preset angle α and the positions of the positioning portions 4.

Further, the number of the positioning portions 4 is not limited to the above two, and may be formed only by 1 as shown in fig. 4, or may be formed by 3 or more, for example, 4 positioning portions which form an angle of 90 ° therebetween.

Further, the notch shape of the positioning portion 4 may be a rectangular shape, and may also be an arc shape, a triangular shape, a trapezoidal shape, or the like, as long as it has a positioning function.

In the above-described manufacturing method, the order of the surface processed portion forming step and the positioning portion forming step may be reversed, that is, the surface processed portion may be formed first and then the positioning portion as described above, or the positioning portion may be formed first and then the surface processed portion may be formed.

The manufacturing method of the cylinder liner according to the present invention may further include a sprayed layer forming step S105.

In the sprayed layer forming step, the outer circumferential surface of the cylinder liner is sprayed to form a sprayed layer.

Specifically, the sprayed layer 5 is formed by ion spraying, arc spraying, or HVOF spraying. The method of forming the sprayed layer 5 is not limited thereto, and a method such as plating may also be employed. When setting the thickness of the sprayed layer 5, it is to be noted that the concave hole portions formed between the adjacent protrusions 3 cannot be filled with the sprayed layer 5. That is, the thickness of the sprayed layer 5 is set to achieve this effect: when the cylinder liner 1 is cast using the casting material of the cylinder block 13, the casting material passing through the cylinder block 13 flows into the recessed hole portion to obtain the anchor effect by the protrusion 3. By forming the sprayed layer 5, the bonding strength between the cylinder liner 1 and the cylinder block 13 can be improved, and the heat radiation property can be improved, so that the usability of the engine can be further improved.

The spray coating range (the formation portion of the spray coating 5) of the spray coating according to the present invention can cover at least the surface finished part 2. Specifically, for example, the portion of the outer circumferential surface 22 of the cylinder liner 1 where the surface processed portion 2 is formed is sprayed to form the sprayed layer 5 as shown in fig. 7. It is also possible to coat the upper portion of the outer peripheral surface 22 of the cylinder liner 1 along the entire circumference with paint to form a sprayed layer 5 as shown in fig. 8. Further, it is also possible to spray the entire outer peripheral surface 22 of the cylinder liner 1 to form the sprayed layer 5 as shown in fig. 9. The above-mentioned sprayed layer 5 is preferably formed as a highly thermal conductive sprayed layer using, for example, aluminum, an aluminum alloy, an aluminum-silicon alloy, iron, an iron alloy, or the like as a spray material.

Further, it is also possible to use different spray materials for forming the spray layers, for example, different spray materials for the upper and lower portions to form the upper spray layer 51 and the lower spray layer 52 as shown in fig. 10. Wherein the thermal conductivity of the sprayed layer 51 is higher than that of the sprayed layer 52. Preferably, the upper sprayed layer 51 is formed as a high thermal conductive sprayed layer, and the lower sprayed layer 52 is formed as a low thermal conductive sprayed layer. The lower sprayed layer 52 of low thermal conductivity is formed of a material capable of reducing the thermal conductivity between the cylinder liner 1 and the body of the cylinder block 13.

Specifically, the low thermal conductivity lower sprayed layer 52 may be composed of: a ceramic material (alumina, zirconia, etc.) spray coating layer, an iron-based material spray coating layer containing a large amount of oxides and pores, a coating layer of a die casting mold release agent formed by coating (a mold release agent formed by mixing vermiculite, Hitazoru and water glass, or a mold release agent formed by mixing a liquid material containing silicon as a main component and water glass, etc.), a coating layer of a coating agent for centrifugal casting of a mold formed by coating (a coating agent formed by mixing diatomaceous earth as a main component, a coating agent formed by mixing graphite as a main component, etc.), a metallic coating layer formed by coating, a coating layer of a low adhesion agent formed by coating (a low adhesion agent formed by mixing graphite, water glass and water, or a low adhesion agent formed by mixing boron nitride and water glass, etc.), a heat-resistant resin layer formed by resin coating, a chemical conversion treatment layer formed by chemical conversion treatment (a chemical conversion treatment layer of phosphate, or a chemical conversion-treated layer of iron tetraoxide).

< method for producing Cylinder Block >

The manufacturing method of the cylinder liner according to the present invention is described in detail above with reference to fig. 11 to 13. A manufacturing method of the cylinder block 13 to which the cylinder liner according to the present invention is applied will be described below with reference to fig. 1 and 14 to 15.

The manufacturing method of a cylinder block including the cylinder liner according to the present invention includes a cylinder liner positioning step S201, a block casting step S202, and a flow path forming step S203.

In the cylinder liner positioning step S201, a plurality of cylinder liners are positioned in a mold such that the plurality of cylinder liners are arranged side by side and the surface processed portions of adjacent ones of the plurality of cylinder liners are opposed in parallel to each other. Specifically, a predetermined cylinder liner fitting portion that fits at least a portion of the cylinder liner 1 to position the cylinder liner 1 may be formed in the mold so that the plurality of cylinder liners are arranged in a straight line and surface processed portions of adjacent ones of the plurality of cylinder liners are opposed to each other.

For example, in order to arrange cylinder liners side by side in the left-right direction in the drawing in the cylinder block as shown in fig. 1, the following procedure may be adopted. In the case where two positioners 4 are provided at points B1, B2 as shown in fig. 11, and the straight line L2 on which the two positioners 4 are located is parallel to the straight line L1 on which the surface processed portion 2 is located, the cylinder liner fitting portion for positioning may be formed as a straight positioning shaft, and by fitting the positioners 4 of the cylinder liner 1 to the straight positioning shaft, a plurality of cylinder liners 1 may be positioned on a straight line. At this time, since the positioning shaft is positioned at a relative position of the mold along the longitudinal direction of the cylinder block 13, when the cylinder liners 1 are positioned by the positioning shaft, the surface processed portions 2 of the adjacent cylinder liners 1 are disposed in a state of being opposed to each other. The positioning portion 4 at the lower end does not have to be located directly below the surface processed portion 2 if the surface processed portions 2 of the adjacent cylinder liners can be located at predetermined positions opposed to each other, and the position of the positioning portion 4 is not particularly limited as long as the cylinder liner 1 can be positioned at the predetermined positions in the mold.

In the block casting step S202, an aluminum alloy molten metal forming the body of the cylinder block 13 is filled into a mold, whereby the cylinder liner 1 is cast to form the basic structure of the cylinder block 13.

In the flow path forming step S203, the basic structure of the cylinder block 13 is cut to form the flow path P of the coolant (see fig. 15). The circulation path P passes through the space S between the surface processed portions of the adjacent cylinder liners 1 as shown in fig. 15 (see fig. 5). Therefore, it is preferable to set the size of the flow path to be smaller than the size of the space S, so that the flow path P can be formed without interfering with the outer periphery of the cylinder liner 1, and thus the flow path P is formed without cutting the cylinder liner 1, which reduces the difficulty of processing, and saves manufacturing cost and time, while also preventing the coolant from leaking from the boundary portion when interfering with the cylinder liner protrusion.

Preferably, the flow path P may be set to have a width of 3mm and a depth of 10 to 30 mm. In addition, the inner peripheral surface 21 of the cylinder liner 1 is also finished. After the completion of the processing, the wall thickness of the cylinder liner 1 is preferably 1.0 to 2.5 mm.

The above is only an example of the flow path P, and the shape and size of the flow path are not limited thereto, and for example, the flow path may be a cylindrical hollow hole or the like.

By manufacturing the cylinder liner according to the present invention and the cylinder block to which the cylinder liner is applied by using the above method, it is not necessary to separate adjacent cylinder liners 1 by a predetermined distance in order to avoid interference of the outer periphery of the cylinder liner 1 with the flow path P, so that the interval (cylinder center distance) between the adjacent cylinder liners can be reduced as much as possible, thereby reducing the size and weight of the entire engine. Further, since the flow path P can be formed without interfering with the outer periphery of the cylinder liner 1 in the cylinder liner of the present invention and the cylinder block to which the cylinder liner is applied, the flow path P is formed without cutting the cylinder liner 1, which reduces the difficulty of processing and saves the manufacturing cost and time.

Further, in the present embodiment, in order to avoid interference between the cylinder liner 1 and the flow path P, only a small portion of the outer circumferential surface (near the upper end portion) is subjected to surface processing so that the size of the surface processed portion is as small as possible, and thus the processing of the protruding portion 3 of the outer circumferential surface can be reduced as much as possible while avoiding the aforementioned interference, and therefore the surface bonding strength between the outer circumference of the cylinder liner 1 and the insert cast material can be maintained as much as possible.

Further, according to the manufacturing method of the cylinder block using the cylinder liner, the cylinder liners can be positioned on a straight line by a simple operation, and the surface processed portions of the adjacent cylinder liners can be opposed to each other.

The above description is only an example of the present application and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A cylinder liner, characterized in that,

2. The cylinder liner of claim 1, wherein,

the predetermined length over which the surface processed portion extends is 10mm or more and 40mm or less, and a recessed depth of the surface processed portion in a radial direction with respect to an outer peripheral surface of the cylinder liner is 0.3mm or more and 2.0mm or less.

3. The cylinder liner according to claim 1 or 2, wherein,

the cylinder liner has a sprayed coating.

4. The cylinder liner of claim 3, wherein,

a portion of the cylinder liner having the surface processed portion is covered with the sprayed layer formed of a sprayed material.

5. The cylinder liner of claim 3, wherein,

an upper portion of the cylinder liner is covered with the sprayed layer formed of a sprayed material along an entire circumferential direction.

6. The cylinder liner of claim 3, wherein,

the entire outer circumferential surface of the cylinder liner is covered with the sprayed layer formed of a sprayed material.

7. The cylinder liner according to any one of claims 4 to 6, characterized in that,

the spraying material is aluminum, aluminum-silicon alloy, aluminum alloy or iron alloy.

8. The cylinder liner of claim 3, wherein,

the sprayed layer is composed of a first sprayed layer covering an upper portion of the outer circumferential surface of the cylinder liner and a second sprayed layer covering a lower portion of the outer circumferential surface of the cylinder liner, and

9. The cylinder liner of claim 8, wherein,

the spraying material for forming the first spraying layer is aluminum, aluminum-silicon alloy, aluminum alloy or iron alloy.

10. The cylinder liner according to any one of claims 1-2, 4-6 and 8-9, characterized in that,

the cylinder liner has at least one locating portion.

11. The cylinder liner of claim 10, wherein,

the position of the positioning portion is associated with the position of the surface finished portion, so that the position of the surface finished portion can be determined using the position of the positioning portion.

12. The cylinder liner of claim 11,

the positioning portion is located at a lower end of the cylinder liner.

13. The cylinder liner of claim 12,

the positioning portion and the circumferential middle position of at least one of the surface processing portions form a predetermined angle in the circumferential direction, and the predetermined angle is any angle within a range of 0 ° or more and 90 ° or less.

14. The cylinder liner according to any one of claims 11 to 13, characterized in that,

the positioning portion has a notch shape in a plan view.

15. The cylinder liner of claim 14, wherein,

the positioning portion has a rectangular shape, an arc shape, a triangular shape, or a trapezoidal shape in a plan view.

16. The cylinder liner of claim 13, wherein

The positioning portion and a circumferential intermediate position of the surface processing portion are circumferentially aligned with each other.

17. A manufacturing method of a cylinder block including a plurality of the cylinder liner of claim 16, the method comprising:

a cylinder liner positioning step of fitting at least a portion of the cylinder liner with a cylinder liner fitting portion provided in a mold, wherein a plurality of the cylinder liners are positioned on a straight line, and the surface processed portions of adjacent ones of the cylinder liners are opposed to each other;

18. The method of manufacture of claim 17, wherein

In the cylinder liner positioning step, the positioning portions of the plurality of cylinder liners are brought into contact with a linear positioning shaft to position the plurality of cylinder liners on a predetermined straight line, and the surface processed portions of adjacent ones of the plurality of cylinder liners are made to oppose each other.

19. A method of manufacturing a cylinder liner, the method comprising:

20. The manufacturing method of claim 19, further comprising:

21. The method of manufacture of claim 20, wherein

22. The method of manufacture of claim 21, wherein

23. The manufacturing method according to any one of claims 19 to 22, further comprising:

24. The method of manufacture of claim 23, wherein

At least a portion of the cylinder liner having the surface finish is covered with the sprayed layer.