CN110894813B

CN110894813B - Cylinder liner, method for manufacturing the same, and method for manufacturing cylinder block using the same

Info

Publication number: CN110894813B
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: 2023-05-02
Anticipated expiration: 2038-08-22
Also published as: CN110894813A

Abstract

The present invention provides a cylinder liner and a method of manufacturing the cylinder liner, characterized in that an outer peripheral surface of the cylinder liner is integrally distributed with a plurality of protruding portions, and the outer peripheral surface of the cylinder liner has surface-processed portions extending downward from an upper end surface by a predetermined length in an axial direction of the cylinder liner at radially opposite sides of the cylinder liner, the surface-processed portions being located radially inward with respect to the outer peripheral surface of the cylinder liner. The invention also provides a manufacturing method of the cylinder block with the cylinder sleeve.

Description

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

Technical Field

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

Background

Cylinder blocks with cylinder liners for engines have been used in practical applications, and cylinder liners are generally applied to cylinder blocks made of aluminum alloy (aluminum silicon alloy, etc.).

With the increasing importance of the state to the conditions such as air pollution that the automotive field produced, put forward stricter energy saving and emission reduction's requirement to the engine, consequently, realize that the engine is lighter is the important measure of coping with energy saving and emission reduction now, and realize that the lightweight of cylinder jacket helps realizing the lightweight of engine. Therefore, how to achieve the weight reduction of the cylinder liner is a problem to be solved by those skilled in the art.

The engine can be light and the oil consumption can be reduced by reducing the core distance or the weight of the cylinder sleeve.

Disclosure of Invention

In view of the above object, the present invention provides a cylinder liner having surface-processed portions extending a predetermined length in an axial direction at radially opposite sides of an outer circumferential surface thereof, and a manufacturing method of the cylinder liner, in which the surface-processed portions are radially inwardly retracted a distance at an axially upper portion as compared to the outer circumferential surface, thus preventing interference between a body of the cylinder liner and a flow path through which coolant flows, thereby allowing the flow path to pass between the cylinder liners without cutting the cylinder liner, which reduces processing difficulty, and saves manufacturing cost and time.

Also, due to the presence of the surface processing portion, it is unnecessary to space adjacent cylinder liners by a predetermined distance in order to avoid interference of the outer periphery of the cylinder liner with the flow path, so that the interval (core 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 surface-machined portion is formed to be as small as possible, so that machining 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 cast material can be maintained as much as possible.

The present invention also provides a manufacturing method of a cylinder block using the cylinder liner, with which the cylinder liner can be positioned on a straight line with a simple operation and the surface-processed portions of the 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,

the cylinder liner has a plurality of protrusions integrally distributed on an outer circumferential surface thereof, an

The outer peripheral surface of the cylinder liner has surface-processed portions extending downward from an upper end surface by a predetermined length in an axial direction of the cylinder liner at radially opposite sides of the cylinder liner, the surface-processed portions being located radially inward with respect to the outer peripheral surface of the cylinder liner.

Further, the predetermined length of the surface finish portion extending is 10mm or more and 40mm or less, and a recessed depth of the surface finish portion in a radial direction with respect to an outer circumferential 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, an upper portion of the cylinder liner is covered with a sprayed layer formed of a sprayed 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 sprayed 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 first sprayed layer has a higher thermal conductivity than 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 locating portion.

Further, the position of the positioning portion is associated with the position of the surface processing portion, so that the position of the surface processing 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 forms a predetermined angle with a circumferential intermediate position of at least one of the surface processing portions in a circumferential direction, the predetermined angle being 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 triangle shape, or a trapezoid 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 comprising:

a cylinder liner positioning step of engaging at least a part of the cylinder liner with a cylinder liner engaging portion provided in a mold to position the cylinder liner in a straight line and to cause the surface-processed portions of adjacent cylinder liners among a plurality 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 cylinder liners positioned; and

and a flow path forming step of forming a flow path of 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 method of manufacturing a cylinder liner, the method comprising:

a cylinder liner casting step of casting a cylinder liner, the outer peripheral surface of which is integrally distributed with a plurality of protruding portions;

a processing portion setting step of setting a processing reference surface on a main body of the cylinder liner, and setting a processing portion to be formed with a surface processing portion at an upper portion of an outer peripheral surface of the cylinder liner in accordance with the processing reference surface such that the processing portions are located at radially opposite sides of the cylinder liner; and

and a surface-machined portion forming step of cutting an outer peripheral surface of the cylinder liner at the machined portion to form a surface-machined portion such that the surface-machined 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-machined portion is located radially inward with respect to the outer peripheral surface of the cylinder liner.

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

and 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 processing portion, so that the position of the surface processing portion can be determined by the position of the positioning portion.

Further, the positioning portion and the circumferential intermediate position of the surface processing portion are aligned with each other in the circumferential direction.

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

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

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

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

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.

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 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 upper partial enlarged view of the 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 a cylinder liner according to a third embodiment of the present invention.

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

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

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

Fig. 12 is another explanatory diagram for setting a processing portion of the manufacturing method of the cylinder liner according to the present invention.

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

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

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

Detailed Description

The technical scheme of the present invention will be clearly and completely described below in connection with specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the preferred embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

First, a 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. The inner peripheral surface of each cylinder liner 1 (see fig. 2, the inner peripheral surface 21 of the cylinder liner 1) forms the 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 a piston.

The outer peripheral surface (see fig. 2, outer peripheral surface 22) of each cylinder liner 1 is brought into contact with the cylinder block 13 by insert casting of a casting material. The cylinder block 13 may be manufactured using a well-known engine insert casting material, such as 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 near the cylinder head 12 is defined as an upper side. Similarly, a portion of the cylinder liner 1 remote from the cylinder head 12 is defined as a lower portion, and a portion of the cylinder liner 1 near the cylinder head 12 is defined as an upper portion.

< Structure of Cylinder liner >

An outer peripheral surface of the cylinder liner is distributed with a plurality of protruding portions, and the outer peripheral surface of the cylinder liner has surface-processed portions extending downward by a predetermined length in an axial direction of the cylinder liner from an upper end surface at both sides opposite in a radial direction of the cylinder liner, the surface-processed portions being located radially inward with respect to the outer peripheral surface of the cylinder liner.

Preferably, the cylinder liner further has a spray coating.

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

Wherein fig. 2 is a perspective view of a cylinder liner according to a first embodiment of the present invention. Fig. 3 is a 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 upper partial enlarged view of the 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 axial centers 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 fig. 3 for enlarged view), which are randomly formed on the outer circumferential surface of the cylinder liner, and which are casting protrusions 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 shape, 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 axially downward from an upper end along an axial direction of the cylinder liner 1 by a predetermined length L (see fig. 4), preferably, the predetermined length L is 10mm or more and 40mm or less.

The surface processed portion 2 may be formed by removing a portion of the protrusion 3 of the cylinder liner 1 by cutting such that the arcuate surfaces at the axially upper portions at the radially opposite sides of the outer peripheral surface 22 are processed into substantially rectangular-shaped flat surfaces such that the surface processed portion 2 is located radially inward with respect to the outer peripheral surface 22 of the cylinder liner 1.

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

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 surface finishing portion 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 liner 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 processing portion 2, so that the flow path P is formed without cutting the cylinder liner 1, which reduces the processing difficulty, and saves the manufacturing cost and time, while also preventing leakage of coolant from the boundary portion when interfering with the cylinder liner protrusion.

Also, due to the presence of the surface processing portion 2, it is unnecessary to space 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 (the 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, only a small portion of the outer circumferential surface is surface-machined in order to achieve avoidance of interference of the cylinder liner 1 with the flow path P, so that the size of the surface-machined portion is as small as possible, whereby machining 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 of the outer circumference of the cylinder liner 1 with the insert cast 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 parts are given the same reference numerals, and the description of the same parts as those of the first embodiment in the present embodiment will be omitted.

As shown in fig. 6, the cylinder liner 1 further 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, since the surface processed portion 2 is formed at diametrically opposite sides in the outer peripheral surface 22, it is difficult to quickly and accurately determine the position of the surface processed portion 2 in the circumferential direction. Therefore, by correlating the position of the positioning portion 4 with the position of the surface processing portion 2, the position of the surface processing portion 2 can be determined simply and quickly by the positioning portion 4 to ensure that the surface processing portions 2 of adjacent cylinder liners 1 are opposed to each other when the cylinder liner 1 is applied.

The position of the positioning portion 4 may be aligned with a substantially middle position in the circumferential direction of the surface processing portion 2 at either side in the circumferential direction. And the position of the positioning portion 4 may be offset by a predetermined angle in the circumferential direction with respect to a substantially intermediate position in the circumferential direction of the surface processing 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 processing portion 2 by the positioning portion 4.

The number of the positioning portions 4 is not limited to 1 shown in fig. 6, and may be plural, for example, two positioning portions 4 opposed to each other in the radial direction, or four positioning portions 4 having an angle of 90 ° between any two of them, and 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 triangle shape, a trapezoid 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. 7-10 show a cylinder liner 1 according to a third embodiment of the invention, which differs from the first and second embodiments only in that the cylinder liner 1 also has a sprayed layer 5. Also, in the present embodiment, the same or similar parts are given the same reference numerals, and the description of the same parts as those of the first embodiment in the present embodiment will be omitted.

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

In addition, since different spray materials have different properties, for example, adhesion and thermal conductivity of iron and aluminum are not greatly different, and aluminum has a cost advantage over aluminum-silicon alloy. Therefore, any of the above-mentioned spray materials may be selected according to the production environment and 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 concave 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 present invention, the sprayed layer 5 is formed to cover at least the surface processed portion 2.

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

As shown in fig. 8, the sprayed layer 5 may also be formed to cover the upper portion of the outer circumferential surface 22 of the cylinder liner 1 along the entire circumferential direction. Thereby improving the cooling performance (heat radiation performance) 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 is improved, so that the usability of the engine can be further improved.

Also, in addition to the same material being used to cover the entire outer circumferential surface 22 as shown in fig. 9, as shown in fig. 10, different spray materials may be used for the upper and lower portions to form the spray layer 51 and the spray layer 52, wherein the upper spray layer 51 covers the upper half of the outer circumferential surface 22 of the cylinder liner 1, the lower spray layer 52 covers the lower half of the outer circumferential 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, aluminum alloy, aluminum silicon alloy, 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 upper temperature of the cylinder liner 1 than the lower temperature, 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 sprayed layer 51 of the upper portion is made to have a higher thermal conductivity than the sprayed layer 52 of the lower portion, the heat dissipation 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 temperature and the lower temperature, and thus suppressing the deformation of the cylinder liner to reduce friction with the piston.

The structure of the cylinder liner 1 in the second embodiment is employed in fig. 7 to 10, however, not limited thereto, but any structure of the first embodiment and modifications and variations of the first and second embodiments may be employed.

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 the heat radiation property. Further, the cylinder liner 1 in the third embodiment can also achieve the same actions and effects as those of the foregoing first and second embodiments.

< method for producing 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 method for manufacturing the cylinder liner according to the present invention includes a protrusion forming step, a processing portion setting step, and a surface processing portion forming step.

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

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

Step S101, a cylinder liner casting step: the cylinder liner is cast to form a cylinder liner in which a plurality of projections are integrally distributed on an outer peripheral surface.

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 200-400 c and in a rotating state, thereby forming a coating layer on the inner surface of the die, the thickness of the coating layer being, for example, 0.5 to 1.1mm. 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 mold in a rotated state. At this time, the concave holes of the coating layer are filled with molten metal, and a plurality of projections 3 are formed. After the molten metal is solidified to form the cylinder liner 1, the coating layer is taken out of the mold together with the cylinder liner 1. The coating agent is removed by, for example, shot peening, thereby manufacturing the basic structure of the cylinder liner 1 having the plurality of projections 3 on the outer peripheral surface thereof. By the above casting process, the plurality of projections 3 are formed randomly on the outer peripheral 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 portion setting step of setting a machining reference plane on a basic structure of the cylinder liner, and setting machining portions to be formed with surface machining portions at an upper portion of an outer circumferential surface of the cylinder liner according to the machining reference plane such that the machining portions are located at diametrically opposite sides of the cylinder liner.

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

By the above-described setting steps, it is possible to determine the upper end portions A1, A2 of the cylinder liner 1 through which the straight line L2 passes, and the upper end portions A1, A2 at the radially opposite sides of the cylinder liner 1 are processing portions to form the surface processing portion 2 at the upper portion of the outer peripheral surface 22 of the cylinder liner 1. Preferably, the plane in which the surface processing portion 2 is located is perpendicular to the straight line L2.

The above setting process of the machining portion of the surface machining portion 2 is only one example, and the present invention is not limited to the above setting process. For example, the straight line in which the processing portion of the surface processing portion 2 is located does not necessarily have to be parallel to the straight line L1, but may be a predetermined angle α with the straight line L1, and the magnitude of the angle α may be set as needed, preferably 0 ° Σ. For example, as shown in fig. 12, a straight line (broken line) L3 is perpendicular to the straight line L2, and thus perpendicular to the straight line L1. In this case, the upper end portions A1 'and A2' through which the straight line L3 passes may be used as the formation portions of the surface processing portion, and in this case, the processing portion of the surface processing portion 2 is perpendicular to the processing reference line L1 (α is 90 °).

Step S103, a surface processing portion forming step of cutting an outer peripheral surface of the cylinder liner at the processing portion to form a surface processing portion such that the surface processing 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 processing portion is located radially inward with respect to the outer peripheral surface of the cylinder liner.

Specifically, at the machining site determined in step S102, the outer peripheral surface 22 of the cylinder liner 1 is subjected to cutting machining by means of cutting machining such as turning machining, milling machining, or the like to cut the plurality of projections 3 at the machining site, thereby machining the arcuate surface at the machining site into a substantially rectangular-shaped flat surface, forming the surface machined portion 2. As shown in fig. 4, the surface processed portion 2 may be formed to extend a predetermined length L (i.e., a rectangular side length L) 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 processed portion 2 in the radial direction with respect to the outer peripheral 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) of the radial width (wall thickness) of the cylinder liner 1 from the recess depth h is 1mm or more to secure the strength of the cylinder liner at the surface processed portion.

The method of manufacturing a cylinder liner according to the present invention further includes a positionable 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 portions B1, B2 can be set as the formation portions of the positioning portions. At the formation site of the positioning portion, the body of the cylinder liner is subjected to cutting processing in the radial direction (from the outer peripheral surface to the inner peripheral surface), thereby forming the positioning portion 4 having a notch shape.

Through the above-described process, the positioning portion 4 makes a predetermined angle α with the surface processing portion 2. For example, when the machining portions A1 and A2 are formed, α is 0 °, and at this time, the position of the positioning portion 4 and the substantially intermediate position in the circumferential direction of the surface machining portion 2 are aligned with each other in the circumferential direction; when the machining portions are A1', A2', α is 90 °, that is, the position of the positioning portion 4 is shifted by a predetermined angle α, α is 90 °, in the circumferential direction with respect to the substantially intermediate position in the circumferential direction of the surface machining portion 2. Thus, the position of the surface processing portion 2 can be determined from the angle α set in advance and the position of the positioning portion 4.

The number of the positioning portions 4 is not limited to the two, and may be 1 as shown in fig. 4, or may be 3 or more, for example, 4 positioning portions having an angle of 90 ° with respect to each other.

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

In the above 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 may be formed 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 spray coating 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 be employed. It is to be noted in setting the thickness of the sprayed layer 5 that the concave hole portions formed between the adjacent protruding portions 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 concave hole portion to obtain the anchoring effect by the protruding portion 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 site of the spray coating 5) of the spray coating according to the present invention can cover at least the surface processed portion 2. Specifically, for example, a portion of the outer peripheral surface 22 of the cylinder liner 1 where the surface processed portion 2 is formed is sprayed to form a sprayed layer 5 as shown in fig. 7. It is also possible to spray the upper portion of the outer circumferential surface 22 covering the cylinder liner 1 in the entire circumferential direction to form a sprayed layer 5 as shown in fig. 8. Further, the entire outer circumferential surface 22 of the cylinder liner 1 can also be sprayed to form a sprayed layer 5 as shown in fig. 9. The above-mentioned spray coating 5 is preferably formed as a high thermal conductive spray coating, in which, for example, aluminum alloy, aluminum silicon alloy, iron alloy, or the like is used as a spray coating material to form a high thermal conductive spray coating.

In addition, different spray materials may be used to form the spray layers, for example, different spray materials may be used 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 spray coating 51 is formed as a spray coating of high thermal conductivity, and the lower spray coating 52 is formed as a spray coating of low thermal conductivity. The low thermal conductivity lower spray coating 52 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 spray coating 52 may be composed of the following materials: a spray coating of a ceramic material (alumina, zirconia, etc.), a spray coating of an iron-based material containing a large amount of oxide and pores, a release agent for die casting formed by coating (a release agent formed by mixing vermiculite, hitazoru, water glass, etc.), a coating of a release agent formed by mixing a liquid material containing silicon as a main component and water glass, etc.), a coating of a coating agent for die centrifugal casting 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 metal coating layer formed by coating, a coating of a low adhesion agent formed by coating (a low adhesion agent formed by mixing graphite, water glass, a low adhesion agent formed by mixing boron nitride and water glass, etc.), a heat-resistant resin layer formed by a resin coating, a chemical conversion treatment layer formed by a chemical conversion treatment (a chemical conversion treatment layer of phosphate, or a chemical conversion treatment layer of iron tetraoxide), etc.

However, in the present embodiment, since the sprayed layer 5 is formed only at the upper portion, or the sprayed layer 51 of the upper portion is made to have a stronger thermal conductivity than the sprayed layer 52 of the lower portion, the heat dissipation 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 temperature and the lower temperature, and thus suppressing the deformation of the cylinder liner to reduce friction with the piston.

< method for producing Cylinder Block >

The method of manufacturing the cylinder liner according to the present invention is described in detail above by referring to fig. 11 to 13. A method of manufacturing 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 14-15.

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

In the 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 surface processed portions of adjacent cylinder liners among the plurality of cylinder liners are opposed in parallel to each other. Specifically, a predetermined cylinder liner mating portion that mates with at least a portion of the cylinder liner 1 to position the cylinder liner 1 such that a plurality of cylinder liners are aligned in a straight line and surface-processed portions of adjacent cylinder liners among the plurality of cylinder liners are opposed to each other may be formed in the mold.

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 positioning portions 4 are provided at points B1, B2 as shown in fig. 11, and a straight line L2 in which the two positioning portions 4 are located is parallel to a straight line L1 in which the surface processing portion 2 is located, the cylinder liner engagement portion for positioning may be formed as a straight line type positioning shaft, and by engaging the positioning portions 4 of the cylinder liners 1 with the straight line type positioning shaft, a plurality of the cylinder liners 1 may be positioned on one straight line. At this time, since the positioning shaft is positioned at the opposite position of the mold along the length direction of the cylinder block 13, when the cylinder liner 1 is 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. If the surface-processed portions 2 of adjacent cylinder liners can be positioned at predetermined positions that are opposite to each other, the positioning portion 4 at the lower end does not have to be located directly under the surface-processed portions 2, 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 cylinder block casting step S202, the aluminum alloy molten metal forming the body of the cylinder block 13 is filled into the 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 a flow path P (see fig. 15) for the coolant. The flow path P passes through a space S (see fig. 5) between the surface-processed portions of the adjacent cylinder liners 1 as shown in fig. 15. 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 circumference of the cylinder liner 1, without cutting the cylinder liner 1, which reduces the difficulty of processing, and saves the 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 30mm. In addition, the inner peripheral surface 21 of the cylinder liner 1 is also subjected to finishing. After the completion of the processing, the wall thickness of the cylinder liner 1 is preferably 1.0 to 2.5mm.

The above is only one 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 columnar 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 using the above-described method, it is unnecessary to space adjacent cylinder liners 1 by a predetermined distance in order to avoid interference of the outer circumference of the cylinder liner 1 with the flow path P, so that the interval (the 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 circumference of the cylinder liner 1 in the cylinder liner and the cylinder block to which the cylinder liner is applied of the present invention, the flow path P is not required to be formed by cutting the cylinder liner 1, which reduces the difficulty of processing and saves manufacturing costs and time.

Further, in the present embodiment, only a small portion (near the upper end portion) of the outer circumferential surface is surface-machined in order to achieve avoidance of interference of the cylinder liner 1 with the flow path P, so that the size of the surface-machined portion is made as small as possible, whereby machining 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 of the outer circumference of the cylinder liner 1 and the insert cast material can be maintained as much as possible.

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

The above description is only an example of the present application and is not intended to limit the present invention, but various modifications and changes will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. 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 is characterized in that,

The outer peripheral surface of the cylinder liner has surface-processed portions extending downward from an upper end surface by a predetermined length in an axial direction of the cylinder liner at radially opposite sides of the cylinder liner, the surface-processed portions being located radially inward with respect to the outer peripheral surface of the cylinder liner,

wherein the cylinder sleeve is also provided with at least one positioning part,

wherein the position of the positioning portion is correlated with the position of the surface processing portion so that the position of the surface processing portion can be determined using the position of the positioning portion,

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

wherein the positioning portion has a notch shape.

2. The cylinder liner of claim 1, wherein,

the predetermined length of the surface finish portion extending is 10mm or more and 40mm or less, and a recessed depth of the surface finish portion in a radial direction with respect to an outer circumferential 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 layer.

4. The cylinder liner of claim 3, wherein,

the 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 the 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, wherein,

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

8. The cylinder liner of claim 7, wherein said aluminum alloy comprises an aluminum-silicon alloy.

9. 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

10. The cylinder liner of claim 9, wherein,

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

11. The cylinder liner of claim 10, wherein the aluminum alloy comprises an aluminum-silicon alloy.

12. The cylinder liner of claim 1, wherein,

the positioning portion forms a predetermined angle with a circumferential intermediate position of at least one of the surface processing portions in a circumferential direction, the predetermined angle being an arbitrary angle in a range of 0 ° or more and 90 ° or less.

13. The cylinder liner of claim 12, wherein,

the positioning portion has a rectangular shape, an arc shape, a triangle shape, or a trapezoid shape.

14. The cylinder liner of claim 12, wherein

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

15. A method of manufacturing a cylinder block including a plurality of cylinder liners according to claim 14, the method comprising:

a cylinder liner positioning step of engaging at least a part of the cylinder liner with a cylinder liner engaging 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 cylinder liners among the plurality of the cylinder liners are opposed to each other;

16. The manufacturing method according to claim 15, 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 cylinder liners among the plurality of cylinder liners are made to oppose each other.

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

a surface-machined portion forming step of cutting an outer peripheral surface of the cylinder liner at the machined portion to form a surface machined portion such that the surface machined 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 machined portion is located radially inward with respect to the outer peripheral surface of the cylinder liner,

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,

wherein the positioning portion has a notch shape.

18. The manufacturing method according to claim 17, wherein

19. The manufacturing method according to claim 18, wherein

20. The manufacturing method according to any one of claims 17 to 19, further comprising:

21. The manufacturing method according to claim 20, wherein

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