KR20130070397A - Cylinder device wear resistance improved by optimal locations of micro texturing - Google Patents

Abstract

PURPOSE: A cylinder device having an improved abrasion resistance by a fine uneven part optimized arranging is provided to reduce an abrasion by a direct contact with a piston by reducing a second conduct generated by a rubbing etc. in a linear reciprocating motion of a piston by forming a fine uneven part in a thrust surface and an anti-thrust surface. CONSTITUTION: A cylinder device having an improved abrasion resistance by a fine uneven part optimized arranging comprises a first concavo-convex region(30), and a second concavo-convex region. The first concavo-convex region is formed at a bore surface of a cylinder block(10) inside. The first concavo-convex region comprises multiple fine uneven parts(31) in an area of 5% to 35% distance from a TDC(Top Dead Center) of a piston moving a linear reciprocating along the bore side of the cylinder. The second concavo-convex region is formed at the bore side of the cylinder of a cylinder block inside. The second concavo-convex region comprises multiple fine uneven parts(41) in an area of 100% to 140% distance from a TDC of a piston. [Reference numerals] (AA) CRS rotation axis

Description

Cylindrical device wear resistance improved by optimal locations of micro texturing}

According to the present invention, wear resistance is achieved by the optimum arrangement of fine recesses and recesses, which can reduce the wear of the piston ring and the cylinder bore surface due to friction by forming the fine recesses in consideration of the operating environment of the internal combustion engine near the top dead center and the bottom dead center of the piston, respectively. This improved cylinder arrangement.

In addition, the present invention relates to a cylinder device having improved wear resistance by an optimum arrangement of fine irregularities that can also reduce wear caused by direct contact with the piston by reducing secondary behavior caused by friction during linear reciprocation of the piston. .

The internal combustion engine uses a cylinder device that moves in response to the explosive force caused by fuel combustion. In a gasoline engine or a diesel engine, fuel is blown together with combustion air in the cylinder device to ignite and explode to operate the cylinder device with the explosive power.

Such a cylinder device is composed of a cylinder block 10 and a piston 20 linearly reciprocating in the cylinder block 10, as shown in FIG. A cylinder liner 11 having excellent wear characteristics may also be inserted.

Therefore, in the case of the type in which the cylinder liner 11 is not additionally inserted, the inner circumferential surface of the cylinder block 10 is the cylinder bore side BS, and in the case in which the cylinder liner 11 is additionally inserted. The inner circumferential surface of the cylinder liner 11 is the cylinder bore surface BS '.

In addition, a piston ring R is fitted to an upper portion of the piston 20 moving along the inside of the cylinder block 10, and a piston skirt 20a is provided below the piston 20, and the piston 20 is provided. ) Is connected to the connecting rod 22 through the piston pin 21, the connecting rod 22 is connected to the crank shaft 23, the CRS shaft is fitted to the crank shaft 23.

However, the piston ring (R) as described above is a linear reciprocating motion on the stroke distance (S) through the cylinder bore surface (BS, BS ') and the lubricant, the point where the moving direction of the piston 20 changes during the reciprocating motion This occurs, and the phenomenon that the speed of the piston 20 is gradually slowed to the instantaneous speed '0' occurs.

The two points where the direction of movement of the piston 20 changes in the stroke distance S are referred to as Top Dead Center (TDC) and Bottom Dead Center (BDC), and the piston 20 is connected to the top dead center (TDC). When passing through the bottom dead center (BDC), there is a lack of lubricant between the piston ring (R) and the cylinder bore surface (BS, BS ') due to the oil shortage and decrease in the ring linear velocity.

Therefore, the direct contact between the piston ring (R) and the cylinder bore surface (BS, BS ') due to the lack of lubricant, there is a problem that increases the friction loss to increase the wear of the two surfaces.

In addition, the piston 20 of the internal combustion engine is the piston pin 21 while reciprocating the stroke distance S under the influence of combustion pressure or friction force generated between the piston ring R and the cylinder bore surfaces BS and BS '. ) Is a pivotal motion, which is called piston secondary motion.

Therefore, the cylinder bore surfaces BS and BS 'are in direct contact with the piston 20 as well as the piston ring R due to the rocking motion during the secondary behavior, and thus the direct contact caused by the rocking motion of the piston 20. Due to this, there is a problem that the wear generation amount of the cylinder bore surfaces BS and BS 'becomes larger.

On the other hand, conventional methods such as heat treatment, surface roughness improvement, and horning have been used to reduce wear of the cylinder bore surfaces BS and BS ', but in recent years, the engine operating environment is the piston ring R and the cylinder bore. As it gradually changes in a direction vulnerable to wear of the surface (BS, BS '), a method for reducing the wear of the piston ring (R) and the cylinder bore surfaces (BS, BS') is required more effectively than the conventional method. have.

Accordingly, Korean Patent Publication No. 2011-26739 discloses a cylinder bore surface to further reduce wear of the piston ring R and the cylinder bore surfaces BS and BS 'than the heat treatment, surface roughness improvement, and honing. By processing fine roughness on (BS, BS '), we propose a processing method that improves lubrication performance while reducing manufacturing cost and processing time.

However, such a rough machining method also cannot cope with all occurrences of wear caused by a large change in instantaneous velocity at the top dead center (TDC) and the bottom dead center (BDC), respectively, during the reciprocating motion of the piston 20. It was not able to cope with the occurrence of wear caused by the oscillation motion during the movement, so it could not be regarded as a micro roughening method that could bring about the optimum effect.

The present invention has been proposed to solve the problems described above, by forming a fine roughness in consideration of the operating environment of the internal combustion engine in the vicinity of the top dead center and the bottom dead center of the piston, respectively, the friction between the piston ring and the cylinder bore surface. It is an object of the present invention to provide a cylinder device having improved wear resistance by an optimum arrangement of fine irregularities that can reduce wear.

In addition, the present invention is to provide a cylinder device having improved wear resistance by the optimum arrangement of fine roughness that can also reduce the wear caused by direct contact with the piston by reducing the secondary behavior caused by friction during linear reciprocation of the piston do.

To this end, a cylinder device having improved wear resistance by the optimum convex and concave arrangement according to the present invention is formed on a cylinder bore side inside a cylinder block, and is formed from a top dead center of a piston reciprocating linearly along the cylinder bore surface. A first uneven portion formed by processing a plurality of fine irregularities in a 5% to 35% distance area; And a second concave-convex portion formed on the cylinder bore surface inside the cylinder block, and formed by processing a plurality of fine unevennesses in a 100% to 140% distance region from the top dead center of the piston.

In this case, the second uneven portion is formed by processing a plurality of fine irregularities in the 110% to 130% distance area from the top dead center of the piston, the second uneven portion of the thrust side (thrust side) present on the cylinder bore surface It is formed in the range of 120 ° to 180 ° from the center point, or is formed in the range of 120 ° to 180 ° from the center point of the anti-thrust side existing on the cylinder bore surface, or the center point of the trust surface. It is preferably formed in the range of 120 ° to 180 ° from and 120 ° to 180 ° from the center point of the anti-trust surface, respectively.

In addition, the fine irregularities constituting the first uneven portion and the second uneven portion are preferably dimple-shaped fine grooves having a circular cross section.

In addition, the micro grooves are preferably 100 to 150um in diameter, 10 to 20um in depth, and 350um to 450um in spacing.

According to the cylinder device having improved wear resistance by the optimum arrangement of micro-corrugations according to the present invention as described above, the oil film formation is maintained in consideration of the operating environment of the internal combustion engine in the vicinity of the top dead center and the bottom dead center of the piston, and the fine wear is collected. By forming the fine irregularities, the wear of the piston ring and the cylinder bore surface caused by friction can be reduced.

In addition, according to the cylinder device with improved wear resistance by the optimum arrangement of micro-corrugation according to the present invention, the secondary behavior generated by friction during linear reciprocation of the piston is formed by forming the micro-corrugation as described above on the thrust surface and the anti-trust surface. By reducing the pressure, wear caused by direct contact with the piston can also be reduced.

1 is a front sectional view showing a general cylinder device.
FIG. 2 is a partial view showing a cylinder device having improved wear resistance by micro-convex optimal arrangement according to an embodiment of the present invention.
Figure 3 is an enlarged view showing the fine irregularities of the cylinder device is improved wear resistance by the fine irregularities in accordance with an embodiment of the present invention.
Figure 4 is a partial view showing a cylinder device with improved wear resistance by the fine concave-convex optimal arrangement according to another embodiment of the present invention.
Figure 5 is a graph showing the wear distribution of the cylinder bore surface of the cylinder device is improved wear resistance by the fine concave-convex optimal arrangement according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described with respect to the cylinder device is improved wear resistance by the fine concave-convex optimal arrangement according to an embodiment of the present invention.

However, the cylinder bore side described below means a surface directly contacting the piston 20 linearly reciprocating. In the case of the type in which the cylinder liner 11 is not additionally inserted as shown in FIG. The inner peripheral surface of the cylinder block 10 will be the cylinder bore surface BS.

On the other hand, in the case where the cylinder liner 11 is additionally inserted, the inner circumferential surface of the cylinder liner 11 will be the cylinder bore surface BS ', and a coating layer coated with various films on the inner circumferential surface of the cylinder block 10. If present, the coating will be a cylinder bore surface.

As shown in FIG. 2, the cylinder device having improved wear resistance by the optimum irregularities in accordance with an embodiment of the present invention is formed on the cylinder bore surfaces BS and BS ′ within the cylinder block 10. (S) the first uneven portion 30 formed near the top dead center (TDC) of the piston 20 linearly reciprocating within the range and the second unevenness formed near the bottom dead center (BDC) A portion 40 is included.

At this time, in order to reduce friction and wear by forming fine irregularities on the cylinder bore surfaces BS and BS ', the shape, arrangement method, and processing area of the fine irregularities should be optimally determined. The shape, the arrangement method and the processing area are greatly influenced by the operating conditions such as the contact form of the two surfaces, the load and the sliding speed.

For example, the shape and arrangement method of the unevenness for minimizing friction and wear vary depending on whether the contact portion is linear, dot-shaped or planar. Therefore, the development of surface irregularities technology for reducing friction and wear should first define the operating environment or operating conditions, and the shape and arrangement of the fine roughness should be selected under the predetermined operating environment or operating conditions.

Thus, in one embodiment of the present invention, the first uneven portion 30 is 5% to 35% distance from the top dead center (TDC) of the piston 20 linearly reciprocating along the cylinder bore surface (BS, BS ') A plurality of fine irregularities 31 are formed in the regions A to B.

In addition, the second uneven portion 40 is formed on the cylinder bore surfaces BS and BS ′ in the cylinder block 10, and has a distance of 100% to 140% from the top dead center TDC of the piston 20. C-D) is formed by processing a plurality of fine irregularities 41.

The first concave-convex portion 30 is formed of a plurality of fine irregularities 31 and is continuously formed along the circumferential direction of the cylinder bore surfaces BS and BS '. In addition, each fine groove 31 has a dimple-shaped microgroove having a circular cross section as shown in FIG. 3, and the diameter Db of the microgroove is 100 to 150um, and the depth Dc. Is 10 to 20 um, and the arrangement interval Da is preferably 350 um to 450 um.

As described above, when the fine concavities (31, 41) are processed at an optimal density at the optimal positions of the cylinder bores (BS, BS '), the liquid lubricant trapped in the fine concavities (31, 41) maintains the oil film formation. This contributes to improving lubrication and reducing wear at the interface.

If too many fine irons (31, 41) are processed, the area of the frictional portion in which the fine irons (31, 41) are not processed is too small, and the surface pressure concentrates and increases in the frictional portion, which deteriorates the frictional characteristics, and conversely, Processing too little of (31, 41) results in a slight improvement and increases fuel consumption or engine oil consumption.

Therefore, the present invention, by forming the fine irregularities (31, 41) as described above, even if the piston 20 linearly reciprocates on the cylinder bore surface (BS, BS '), the piston ring (R) and the cylinder bore surface It suppresses the phenomenon that a lubricant runs short between (BS, BS '). In addition, due to the high combustion pressure and the heat of combustion due to the operating characteristics of the internal combustion engine, the cylinder bore surfaces BS and BS 'are prevented from operating in a state in which engine oil is insufficient.

Hereinafter, a cylinder device in which wear resistance is improved by an optimum irregularities arrangement according to another embodiment of the present invention will be described.

As shown in (a) of FIG. 4, a cylinder device having improved wear resistance due to the finely concave-convex optimal arrangement according to another embodiment of the present invention may be formed on the cylinder bore surfaces BS and BS 'inside the cylinder block 10. The first uneven portion 30 formed near the top dead center TDC of the piston 20 linearly reciprocating within the range of the stroke distance S, and the second uneven portion 40a formed near the bottom dead center BDC. ).

The first concave-convex portion 30 includes a plurality of fines in a 5% to 35% distance region A to B from a top dead center TDC of the piston 20 linearly reciprocating along the cylinder bore surfaces BS and BS '. The unevenness 31 is formed by processing. The first uneven portion 30 is formed throughout the circumferential direction of the cylinder bore surfaces BS and BS ', and is the same as the embodiment of the present invention described above.

However, the second uneven portion 40a is formed by processing a plurality of fine irregularities 41 in the region 110% to 130% of the distance C'-D 'from the top dead center TDC of the piston 20. Is different from one embodiment of the present invention in which the fine concavities and convexities 41 are formed in the region 100 to 140% from the top dead center TDC of the piston 20.

In addition, another embodiment of the present invention, as shown in Fig. 4 (b), the second uneven portion 40a is 120 ° from the center point of the thrust side (thrust side) present in the cylinder bore surface (BS, BS ') Or 180 ° to 180 ° from the center of the anti-thrust side.

Of course, it is obvious that the angle of 120 ° to 180 ° from the center point of the trust surface and 120 ° to 180 ° range from the center point of the anti-trust surface may be formed, respectively. , BS ') is different from the embodiment of the present invention, which is formed throughout the circumferential direction.

As shown in (b) of FIG. 4, the second uneven portion 40a has a direction perpendicular to the 'CRS rotation axis', which is the rotation axis of the crankshaft 23 (that is, the center point of the thrust surface or the anti-trust surface). The reference point may be formed in the range of 120 ° to 180 ° in the clockwise direction, or may be formed in the range of 120 ° to 180 ° in the counterclockwise direction.

The fine roughness 41 of the second uneven portion 40a is made of a fine groove of a dimple shape having a circular cross section as in the embodiment of the present invention described with reference to FIG. 3. The diameter Db of each microgroove is 100 to 150um, the depth Dc is 10 to 20um, and the arrangement interval Da is 350um to 450um.

As described above, another embodiment of the present invention corresponds to the top dead center (TDC) and the bottom dead center (BDC) where the instantaneous speed of the piston 20 linearly reciprocates rapidly, and the oscillation motion during the piston secondary motion. Fine irregularities (31, 41) are formed on the trust surface and the anti-trust surface, which cause the occurrence of cracks.

That is, the piston 20 is the piston pin 21 by the pressure distribution that the explosion pressure of the engine combustion chamber is applied to the upper surface of the piston 20 or the friction force between the piston ring (R) and the cylinder bore surface (BS, BS '). It will descend to one side with respect to the center.

At this time, the outer diameter surface of the inclined direction of the piston 20 is referred to as the thrust surface and the direction opposite thereto is called the anti-trust surface, the present invention is the thrust surface and the anti-trust surface of the cylinder bore surface BS, BS The irregularities 31 and 41 are formed on the surface corresponding to the friction and wear.

Therefore, the entire piston 20 including the piston skirt 20a, as well as the cylinder bore surfaces BS and BS 'and the piston ring R, due to the rocking motion during the secondary behavior, is the cylinder bore surface BS, Severe wear caused by direct contact with the BS 'can also be significantly reduced.

Hereinafter, the abrasion test results of the cylinder device with improved wear resistance by the micro-roughness optimum arrangement according to the present invention will be described.

First, a seal is used as shown in FIG. 5 to confirm an optimum processing area of the fine concave-convexities 31 and 41 that can reduce wear of the piston ring R and the cylinder bore surfaces BS and BS 'of the internal combustion engine. The wear state of the cylinder bore surfaces BS and BS 'was measured.

Looking at Figure 5, it can be seen that a large wear occurs in the 16 ~ 19cm region and 4 ~ 6cm region. The stroke S of this engine is 12.6cm, and the wear area of FIG. 5 is expressed as A, B, C, D, S of FIG. 4, where A / S = 8%, B / S = 32%, and C / S = 110% and D / S = 135%.

That is, in the cylinder bore surfaces BS and BS 'used for the internal combustion engine, an area of 8 to 32% of the stroke distance S and 110 to 135 from the top dead center TDC of the cylinder bore surfaces BS and BS'. It can be seen that the most wear occurs in the% area.

As described above, the oil film thickness between the piston ring R and the cylinder bore surfaces BS and BS 'decreases in the stroke distance S at both ends of the stroke 20 in which the direction of movement of the piston 20 changes, thereby increasing friction. This means that large wear occurs.

In addition, when the micro-roughness (31, 41) proposed in the present invention is processed in the optimum placement area in consideration of the above operating characteristics, the optimum that the wear of the piston ring (R) and the cylinder bore surface (BS, BS ') can be reduced It can be improved to the state of.

Next, in order to confirm the wear improvement effect of the piston ring (R) and the cylinder bore through the optimum arrangement of the fine concave-convex (31, 41) proposed in the present invention, the wear test was performed as shown in Table 1 below.

The fine irregularities 31 and 41 were processed into a rectangular array in such a manner that the diameter Db of the fine irregularities 31 and 41 was 100 mm, the depth Dc was 15 mm, and the arrangement interval Da was 350 mm. As shown in FIG. 4, the first uneven portion 30 near the top dead center TDC is machined on the entire cylinder bore surfaces BS and BS ', and the second uneven portion 40a near the bottom dead center BDC is formed of the engine. Only part of the trust / anti-trust region was machined.

This is because the bottom dead center (BDC) region is more likely to be in direct contact between the piston 20 and the cylinder bore surfaces BS and BS 'according to the secondary behavior than the top dead center (TDC) region. This is because the machining area is set in consideration of the skirt 20a of the piston 20.

[Table 1]

Test Results The wear improvement effect of 'Example 2' and 'Example 5' of [Table 1] was excellent, but this is not an optimized embodiment, so the 9 test results of [Table 1] were statistically analyzed for the maximum improvement effect. Derived the expected 'Example 10'.

The results are shown in [Table 2]. "Comparative Example" shown in [Table 2] is a test result for not processing the fine iron (31, 41), as can be seen in the [Table 2] the amount of wear of 'Example 10' is 'Comparative Example' Abrasion was improved by more than 45% of the amount of wear, and the wear improvement effect was superior to 'other examples 1 to 9'.

That is, in the area of 10-30% and 110-130% at the top dead center (TDC) based on the total stroke distance S, and at 150 ° in the cylinder bore planes (BS, BS ') in the trust / anti-trust direction. It was confirmed that the arrangement of the microconvexities (31, 41) can reduce the wear by more than 45%.

[Table 2]

Based on the test results, the diameter (Db), depth (Dc), and arrangement of the round micro-convexities (31, 41) are further optimized to further reduce wear of the piston ring (R) and the cylinder bore surfaces (BS, BS '). The wear test was performed as shown in [Table 3] using the distance Da as a design variable. At this time, the processing region of the fine roughness 31, 41 was set in the same manner as in Example 10.

[Table 3]

As a result of the test, 'Example 12' and 'Example 15' were excellent in improving abrasion, but this was not an optimized embodiment, and thus the maximum improvement effect was expected by statistically analyzing the nine test results of [Table 3]. Example 20 was derived and the results are shown in [Table 4].

[Table 4]

Example 10 shown in [Table 4] is the test result before optimizing the design variables of the circular fine irregularities (31, 41) and 'Comparative example' is the test result for not machining the fine irregularities (31, 41). to be.

As can be seen in Table 4, the wear amount of 'Example 20' was improved by more than 58% of the wear amount of 'Comparative Example', and the wear improvement effect was superior to that of 'Example 10'.

That is, when the circular micro-convexities 31 and 41 having a diameter Db of 120 mm, a depth Dc of 15 mm, and an array gap Da of 400 mm are disposed in the region of the 'Example 10', the piston ring R and the cylinder are processed. Abrasion of the bore surface (BS, BS ') was confirmed to be reduced by nearly 60%.

The specific embodiments of the present invention have been described above. It is to be understood, however, that the scope and spirit of the present invention is not limited to these specific embodiments, and that various modifications and changes may be made without departing from the spirit of the present invention. If you have, you will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

10: cylinder block 11: cylinder liner
20: piston 20a: skirt
21: piston pin 22: connecting rod
23: crankshaft (CRS) 30: first groove portion
40, 40a: second recess 31, 41: uneven
BS, BS ': Cylinder bore surface R: Piston ring

Claims (4)

It is formed in the cylinder bore surface (BS, BS ') in the cylinder block 10, from 5% to the top dead center (TDC) of the piston 20 linearly reciprocating along the cylinder bore surface (BS, BS') A first concave-convex portion 30 formed by processing a plurality of fine concave-convex portions 31 in a 35% distance region; And
It is formed on the cylinder bore surfaces BS and BS 'inside the cylinder block 10, and processes the plurality of fine rough grooves 41 at a distance of 100% to 140% from the top dead center TDC of the piston 20. The second concave-convex portion (40) formed by; and the cylinder device is improved wear resistance by the fine concave-convex optimal arrangement, characterized in that it comprises a. The method of claim 1,
The second uneven portion 40,
It is formed by processing a plurality of fine irregularities 41 in the region 110% to 130% distance from the top dead center (TDC) of the piston 20, the second uneven portion 40a is the cylinder bore surface (BS, BS The center point of the anti-thrust side which is formed in the range of 120 ° to 180 ° from the center point of the thrust side present at '), or which exists on the cylinder bore surfaces BS and BS'. It is formed in the range from 120 ° to 180 ° from, or 120 ° to 180 ° from the center point of the trust surface and 120 ° to 180 ° from the center point of the anti-trust surface, respectively, characterized in that the fine Cylinder device with improved wear resistance due to uneven optimum placement. The method according to claim 1 or 2,
The fine irregularities 31 and 41 constituting the first uneven portions 30 and the second uneven portions 40 and 40a, respectively,
A cylinder device with improved wear resistance by an optimal convex-concave arrangement, characterized in that the groove is a dimple-shaped fine groove having a circular cross section. The method of claim 3,
The fine groove,
Diameter (Db) is 100 to 150um, depth (Dc) is 10 to 20um, the arrangement interval Da is 350um to 450um, characterized in that the wear resistance is improved cylinder arrangement improved by fine concavity.

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