JPS625696B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a composite cylinder liner raw material, and in particular, the wear resistance of the inner surface of the cylinder liner is extremely high on the piston top dead center side, and the other parts have normal wear resistance. The present invention relates to a method for manufacturing a composite cylinder liner raw material that can sufficiently cope with the wear characteristics between the cylinder liner inner surface and the piston during up-and-down strokes and prevent uneven wear on the cylinder liner inner surface. Conventional cylinder liner rough material is generally obtained by casting. When obtained by casting in this way, the material of the cylinder liner rough material is a wear-resistant metal such as cast iron (pearlite cast iron, high carbon eutectic cast iron, high carbon bainitic cast iron, etc.) or Al- Consisting only of aluminum alloys that contain more Si than the eutectic component (12.2% by weight) of Si-based alloys, the cylinder liner is machined by cutting, honing, etc. after casting, and the wear resistance of the inner surface of the cylinder liner is maintained over the entire range. It is uniform. By the way, changes in the wear characteristics between the inner surface of the cylinder liner and the piston during the reciprocating stroke of the piston are as follows:
The amount of wear is large near the top dead center of the piston (the top spring position at the top dead center), and it is small near the bottom dead center of the piston, so the wear resistance of the inner surface of the cylinder liner is large near the top dead center of the piston, and the wear resistance of the other parts is large. Then, it is sufficient to have normal abrasion resistance, that is, a certain degree of abrasion resistance. As a manufacturing method for obtaining a composite cylinder liner rough material in which the wear resistance of the cylinder liner inner surface changes as described above, surface treatment techniques such as plating or thermal spraying may be used. In the case of the plating described above, the inner diameter of the piston top dead center side of the inner surface of the cylinder liner rough material obtained by casting is expanded by an amount corresponding to the thickness of the plating layer from other parts, and the wear-resistant part is By separately plating a metal or the like with excellent durability and then honing the entire inner surface of the cylinder liner, it is possible to obtain a cylinder liner in which the wear resistance of the inner surface of the cylinder liner changes. However, in the case of plating, there are many problems with waste liquid treatment in the plating process, the plating process takes a relatively long time, and the machining of the inner surface of the cylinder liner as a pre-processing is complicated. There is a problem that the manufacturing cost becomes significantly high. In addition, in the case of thermal spraying, the inner diameter of the cylinder liner rough material on the piston top dead center side is expanded by an amount corresponding to the thickness of the thermal sprayed layer, as in the case of plating, and the inner diameter of the cylinder liner rough material on the piston top dead center side is expanded from other parts. This method involves thermal spraying a metal etc. with excellent abrasion resistance, and then honing the entire inner surface of the cylinder liner raw material to obtain a cylinder liner whose inner surface has variable wear resistance. However, it takes a very large number of man-hours to form a sprayed layer with a uniform thickness, and the machining of the inner surface of the cylinder liner rough material as a pre-process is also complicated, which raises the problem of extremely high manufacturing costs. be. Therefore, in order to solve the above-mentioned problems based on surface treatment techniques such as plating or thermal spraying, the inventors made the inner part of the piston, which corresponds to the top dead center side, a material with low plastic deformability and excellent wear resistance. Composite cylinder liner rough material that achieves the intended purpose by molding composite cylinder liner rough material, which is made of a material that has plastic deformability and a certain degree of wear resistance, and the other parts are made of a material that has plastic deformability and a certain degree of wear resistance. Developed a manufacturing method. That is, to explain the outline thereof, Fig. 1a shows an example of the process of obtaining a composite cylinder liner raw material by the above manufacturing method, and in the same figure, material A having excellent wear resistance and low plastic deformability, and material A having low plastic deformability. Using a laminated disc slag M' made of material B which has high wear resistance and a certain degree of wear resistance, material A with better wear resistance is used on the punch 1 side, and material A with better plastic deformability is used on the die 2 side. Charge the laminated disc slug M' so that the material B is located, and after charging, move the punch 1 downward to pressurize the upper end M'a of the laminated disc slag M', and push the punch 1 out by pushing out the rear container. The composite cylinder liner raw material P' (container raw material) is formed by extruding the laminated disk slug M' from the gap 2a between the cylinder liner and the die 2 in the direction opposite to the downward movement direction of the punch 1. . In the composite cylinder liner raw material P' obtained by the above manufacturing method, since the material B has better plastic deformability than the material A, when it becomes the container raw material P', the material cross section in the axial symmetry plane is As shown in Figure 2a, a hollow composite cylinder liner rough material is obtained in which the wear resistance of the inner surface of the cylinder liner rough material is high near the top dead center of the piston, and which has a certain degree of wear resistance elsewhere. However, unless material B has a considerably higher plastic deformability than material A, it will be difficult to form it. Further, as a modification of the above manufacturing method, if the manufacturing method is as shown in FIG. 1b, the interface of the laminated disc slug M' does not come into contact with the die inner wall 2b, and has the material cross section shown in FIG. 2a. Container raw materials can be obtained. However, in the manufacturing method shown in FIG. 1b, the degree and angle of chamfering of the laminated disk slug M' must be determined, and in the manufacturing method shown in FIG. 1c, the size of the clearance x must be determined. Depending on the extent, a problem arose in that it was difficult to reliably obtain the desired ratio of L _A :L _B in the cross section of the material shown in FIG. 1a. Furthermore, as shown in Figure 1d, material A with better wear resistance is replaced with material B with better plastic deformability.
Using the embedded composite disc slug M' embedded in the mold, the composite interface of this material is molded so as not to come into contact with the inner wall of the die during the initial process of extruding the rear container. This ensures that the desired L _A :L _B ratio is obtained. However, if the bottom P'c of the composite cylinder liner rough material P' of FIG. 2a is punched out as shown in FIG. 2b,
Since the composite interface P'a is exposed on the inner surface of the cylinder, it is necessary to remove the portion P'b corresponding to the material B by cutting or the like, resulting in a problem of poor material yield. The present invention has been made for the purpose of providing a manufacturing method for a composite cylinder liner that can further improve the above-mentioned method and solve the above-mentioned problems. As a composite cylinder liner that is large in the vicinity and has normal wear resistance in other parts, it prevents uneven wear on the inner surface of conventional cylinder liners, eliminates problems with solutions such as plating or thermal spraying, and also In order to avoid the influence of frictional force due to the inner wall of the die at the material interface and further improve the material yield, a concentric composite disc material is used as the composite cylinder liner raw material, and the interface of this material is used for rear container extrusion. In the initial process, the cylinder liner material is formed by backward container extrusion while avoiding contact with the inner wall of the die, thereby producing a composite cylinder liner material that has the initial material surface and the bottom of the container is made of a material with excellent wear resistance. This makes it easy to use, significantly increases productivity, and greatly contributes to cost reduction. Next, the present invention will be explained with reference to the embodiments shown in FIGS. 3 to 5. FIG. 3 shows an outline of the manufacturing process of the material used in the present invention. Material B, which has plastic deformability and a certain degree of abrasion resistance, is pressed or machined into a disc-shaped material with an inner diameter of a circular center. [Figure 3a]. Next, the above material B
A concentric composite disk material M is obtained by compounding the material A with excellent wear resistance inside the cylinder, that is, in the hollow portion 4. The burying process of the above material A is shown in Figures 3b to 3e.
There is a method shown below. That is, the method shown in FIG. 3b is obtained by filling the hollow portion 4 of material B with powder of material A and then sintering it. Further, in the method shown in FIG. 3c, the cylindrical material B is placed on the mold 21, and the mold 21
Boiled water is poured into the hollow part 4 of the material B which has been heated in advance. Furthermore, the method of FIG.
A material B is placed on top of the material B, a billet of the raw material A is inserted into the hollow part 4 of the material B, and the material B is pressed in the direction of the arrow 31 and rotated in the direction of the arrow 32 to perform friction welding.
After pressing, material A and material B are combined by cutting along virtual line C to obtain a composite material. Furthermore, in the method shown in FIG. 3e, the material B is placed on the mold 22.
Then, after placing the material A in the hollow part 4 of the material B, pressure is applied in the direction of the arrow 31 and welded together by forging to form a composite disk material M as shown in FIG. 3f. get. In addition to the method shown in FIG. 3, an extrusion process as shown in FIG. 4 may be used to continuously composite material A and material B. That is, the fourth
As shown in Figure a, an extruded tube made of cylindrical material B that has some degree of wear resistance is filled with powder of material A that has wear resistance, one end of which is closed with a disc B' made of material B, and waxed. A composite billet S is obtained by fixing by bonding, welding, etc. [Fig. 4b]. The billet S thus obtained is heated and charged into a container 13 as shown in FIG. Shape. By hot forward extrusion of the composite billet S, the powder made of material A is sintered and firmly joined to the hollow tube made of material B, resulting in a powder made of material A and material B as shown in Fig. 4d. A composite rod T is obtained. By cutting this composite rod T along the imaginary line C shown in FIG. 4d, the concentric disk material M shown in FIG.
is obtained. In addition, when obtaining a composite rod T made of material A and material B by hot forward extrusion shown in FIG. 4, as material A shown in FIG. It may also be cast into a pipe. The hot forward extrusion shown in FIG. 4c eliminates casting defects (pores such as cavities) in the material A, and provides a strong bond between the materials A and B. By the method described above, the diameter d as shown in FIG.
It is possible to obtain a concentric composite disc material M having a thickness of _A and a thickness h and incorporating the material A in the hollow portion 4. However, in the figure, _dB and h are the diameter and thickness of material B, respectively. Note that the method for compounding material B with material A is not limited to the above five methods. Next, in order to form a hollow composite cylinder liner raw material by extruding the concentric composite disk material M formed as described above into a rear container, a punch 1 and a stripper 3 are used as shown in FIG. 5a. The concentric composite disc material M is charged into the mold. Next, as shown in FIG. 5b, when the punch 1 is operated to pressurize the upper end Ma of the concentric composite disc material M, the punch 1 moves from the gap 2a between the punch 1 and the die 2 in a direction opposite to the downward movement direction of the punch 1. The material M is extruded. In the initial stage of backward extrusion due to the pressurization of the punch, that is, in the process until the extruded tip of the material M leaves the die inner wall 2b [Fig. As can be seen from Figure 5 b and c above, a force will be applied.
The composite interface between material A and material B constituting the concentric composite disc material M does not contact the die inner wall 2b at all, and therefore both material A and material B forming the material M are punched at the same time. Extrusion is started by applying pressure by No. 1. On the other hand, in the process from the middle to late stage of backward extrusion [Fig. 5 d], material B has better plastic deformability than material A, so the material cross section in the axially symmetrical plane of container raw material P is It becomes the shape shown in the figure. Further, since the composite shape of the material A and the material B is made concentric, the bottom part Pc of the container raw material P formed by rear container extrusion can be made of only the raw material A, as shown in FIG. Furthermore, Fig. 5 e and f
As shown in , the container blank P is taken out from the mold, and then the bottom Pc of the container blank P is punched out to obtain a hollow composite cylinder blank. In addition, the material A having excellent wear resistance constituting the concentric composite disk material M is a material having a higher Si content than the eutectic component (12.2 wt% Si) of the Al-Si alloy.
For example, an Al alloy containing 22 wt% Si is used as a material B having plastic deformability and a certain degree of wear resistance.
Al alloy containing 12.2 wt% Si (JIS standard A4032
equivalent) is used. Al containing 22 wt% Si as mentioned above
Because the alloy has a large amount of primary Si,
Increases Si surface area and significantly improves wear resistance. However, because the amount of primary Si that does not deform increases, its plastic deformability is significantly inferior. In addition, the JIS standard A4032 alloy is for die forging.
It is a type of Al alloy, and is usually forged at 350 to 450°C, and its plastic deformability is high. By laminating this alloy with the aforementioned Al alloy containing 22% Si by weight, the lack of plastic deformability of the alloy is compensated for. In this case, the processing temperature is 350 to 450°C, and the shape ratio of material A and material B, that is, the diameter ratio d
By appropriately changing _A / _dB [FIG. 3f], it was possible to change the portions L _A :L _B with different Si contents on the inner surface of the cylinder liner. Furthermore, as another example, as shown in Fig. 4, when a concentric composite material M is continuously made by hot forward extrusion, as a material A having excellent wear resistance, (1) Copper coating graph Aito powder - Cu powder - Si powder - Mg powder - balance Al powder (2) Copper-coated MoS ₂ powder - Cu powder - Si powder - Mg powder - balance Al powder (3) Si powder - Cu powder - Mg powder - Pb powder - Ceramic (e.g. Al ₂ O ₃ · SiO ₂ · Si ₃ N ₄ ) powder - remainder
An Al powder alloy consisting of Al powder is used. The specific composition is shown in Table 1. In addition, as material B having plastic deformability and wear resistance to a certain extent, A390 alloy (16 to 18 wt% Si-4.0 to 5.0 wt% Cu-0.6 to
1.15wt%Fe−0.45~0.65wt%Mg−0.1wt%
Mn - 0.1% by weight or less Zn - 0.2% by weight or less Ti - 0.02
An extruded tube with a weight % or less of P) is used. Among the Al powder alloys shown in Table 1, the wear resistance of powders (1) and (2) sintered under normal molding and sintering conditions was measured by the Chimken wear test, and the wear amount was 3.8 for each. mm and 2.5 mm. On the other hand, the Al-hypereutectic Si alloy material of the former example has a thickness of about 5.0 mm, and is therefore suitable for cases with more severe wear conditions. In addition, the Chemtin wear test conditions were a load of 20 bs and a circumferential speed of 2 m/min.
sec, lubricating oil (machine oil #50) 0.5 cylinder liner/
min, test time is 50 hours. Gray cast iron (equivalent to JIS standard FC20) was used as the mating material, and this was made into a ring shape, and the width of the wear scar formed on the example test piece made of the powders (1) and (2) was determined. Furthermore, among the Al powder alloys shown in Table 1, powders (3A), (3B), and (3C) were molded using the normal molding method and sintering conditions, and the wear amount was measured using a pin disc type abrasion tester. and measured the friction coefficient. The results are shown in Table 2. In the Al-hypereutectic Si alloy material of the former example, the wear amount and friction coefficient of the pin and disk were 250 μm, 20 μm, and 0.04 μm, respectively.
Therefore, it is suitable for cases with more severe wear conditions. The pin disk type wear test was carried out using a test machine shown in FIGS. 7a and 7b, using a 5 mm x 10 mm prismatic pin as a test piece. That is, a rotating member 60 and a disk 6 whose surface is plated with chrome.
The test piece 61 is held between the load cell 65 and the load cell 65, and a predetermined amount of oil is injected from the oil inlet and pressurized in the direction of the arrow 64, and the rotating member 60 is rotated to cause friction in the direction of the arrow 67. The load is recorded by the recorder 66. The wear test conditions and friction coefficient test conditions for determining the wear coefficient are shown in Tables 3 and 4, respectively.
Shown in the table. In addition, when the A390 alloy is heated to 400°C or higher, it has sufficient forgeability and high plastic deformability (8th
(Fig.), the above-mentioned Al
Compensates for the lack of plastic deformability of powder alloys. After filling the above-mentioned Al alloy powder (material A) into the above-mentioned A390 alloy hollow tube (material B) and compacting it,
One end is closed with a disk B' made of A390 alloy and soldered [Fig. 4 a, b]. Then, as shown in FIG. 4c, the composite billet S heated to 450 DEG C. is charged into the preheated container 13 and extruded forward by the ram 11. The A390 alloy hollow tube used for hot forward extrusion has an outer diameter of 199 mm, an inner diameter of 148 mm,
They are 125mm and 102mm. A hollow tube of the above dimensions and
A composite billet S made of an Al powder alloy is hot forward extruded at an extrusion ratio (cross-sectional area before/cross-sectional area after extrusion) set to 5. Thereafter, it is sawn to a thickness of 49 mm as shown in Figure 4. By the above method, the dimensions d _A and d _B shown in Fig. 3 f are obtained.
and h are 89, 66, 49mm, 89, 56, 49 respectively
Three types of concentric composite disc materials M with sizes of 1.5 mm, 89 mm, 46 mm, and 49 mm were obtained [Fig. 9a]. FIG. 9b shows the composite interface of the X section when powder 3A was used, and complete bonding of material A and material B was achieved by the above method. Next, the concentric composite disk material M formed as described above is extruded into a rear container by the method shown in FIG. 5, and a hollow composite cylinder liner raw material P as shown in FIG. Obtained. Fig. 10b shows the composite interface of the Y section in Fig. 10a, but as shown in Fig. 6, the inner surface of the hollow composite cylinder liner rough material is L _A : L _B , and at the same time the bottom part Pc is also made of material. B, and all you need to do is punch out the bottom part Pc. FIG. 10c shows a hollow composite cylinder liner raw material P' in which rear container extrusion is performed using the embedded composite disk material M' as shown in FIG. 1d. The inner surface of the embedded composite cylinder liner rough material can be L _A :L _B , but the first
As seen in Figure 0d, the bottom part P'c consists of material A and material B, and when the bottom part is punched out, the composite interface P'b is exposed. Note that Table 5 shows the processing conditions for extruding the rear container shown in FIG. A hollow composite cylinder liner material P having an outer diameter of 89 mm, an inner diameter of 76 mm, a container height of 155 mm, and a container bottom thickness of 10 mm was formed from a concentric composite disk material M with a diameter of 88 mm and a thickness of 49 mm. Also, the diameters d _A / d _B of material A and material B shown in Fig. 3 f = 88/66, 88/56
From the 88/46 concentric composite disc material M, hollow composite cylinder liner rough material P shown in FIG. 6 with L _A :L _B =140/15, 112/43 and 70/85 was obtained. Furthermore, graphite, activated carbon, ceramics (Al ₂ / SiO ₂ / Si ₃ N ₄ , etc.) are used as materials A with excellent wear resistance when manufacturing concentric composite disk material M by hot forward extrusion as shown in Fig. 4. Contains wear-resistant particles such as
Al composite cast material can also be used. The specific composition is Al-2 to 4% by weight Cu-8.5
~10.5wt%Si−0.5~15.0wt%Mg−0.50~1.50
It is an Al casting alloy of 5% by weight Ni (AC8B of JIS standard) and 5% by weight Al ₂ O ₃ -5% by weight graphite, and the above-mentioned
An Al composite cast material obtained by stirring the Al casting alloy in a solid-liquid coexistence state and adding the wear-resistant particles described above is cast into an extruded tube made of A390 alloy. Next, material A (Al composite cast material) and material B (A390
A composite rod T of the alloy (alloy) is produced and cut along the imaginary line C shown in FIG. 4d to obtain a concentric composite disc material M. The composite interface between materials A and B is similar to the photograph shown in FIG. 9, and complete bonding was achieved by the method described above. In addition, the above Al composite cast material (AC85-5
(wt% Al ₂ O ₃ -5 wt% graphite), the wear and friction coefficients of the pin and disk were 30 μm and 5, respectively, in the pin-disc wear test under the conditions described above.
μm and 0.028, and is suitable for cases with more severe wear conditions. The above Al composite cast material (material A) and the above
When a concentric composite disc material M made of A390 alloy (material B) is extruded into a rear container in the manner shown in Fig. 5 under the aforementioned processing conditions (Table 5),
A hollow composite cylinder liner rough material P shown in Figure a was obtained. As is clear from the above description, according to the present invention, a centrifugal composite disk material composed of a material with excellent wear resistance and a material with plastic deformability and a certain degree of wear resistance is used. The concentric composite disc material is extruded into a rear container with a punch, and while the rear container extrusion is continued so that the composite interface of the concentric composite disc material does not contact the inner wall of the die during the initial process, the inner surface of the cylinder liner in the up and down process of the piston is It is possible to reliably and easily form a hollow composite cylinder liner raw material in which the wear resistance near the top dead center of the piston on the inner surface of the cylinder liner is greater than that of other parts according to the wear characteristics of the cylinder liner. can. Furthermore, since the concentric composite disk blank is used, the container bottom of the hollow composite cylinder liner raw material can also be made of a material with excellent wear resistance, which improves material yield. Therefore, it is possible to increase the productivity of this type of hollow cylinder liner and greatly contribute to cost reduction while improving material yield.

【table】

【table】 [Brief explanation of the drawing]

In Fig. 1, a, b, c, and d are explanatory diagrams showing problems in the inventive process of the present invention, and Fig. 2 a, b are hollow composite cylinder liner roughness when laminated or embedded composite disc materials are used. A half-cut longitudinal sectional front view of the material, FIGS.
Figures a, b, c, and d are explanatory diagrams showing an example of manufacturing a concentric composite disk material by hot forward extrusion in the present invention, and Figures a, b, c, d, e, and f are manufacturing steps of the present invention. FIG. 6 is a half-cut longitudinal sectional front view of the hollow cylinder liner rough material according to the present invention, and FIG. 7a
is a schematic cross-sectional view of the pin disk type abrasion tester, No. 7
Figure b is a front view of the testing machine, Figure 8 is a graph showing the relationship between plastic deformability of A390 alloy and temperature, and Figure 9 a is a cross-sectional view of the concentric composite disc material used in one embodiment of the present invention. , FIG. 9b is a photograph showing the metallographic structure of the composite interface part of the X section in FIG. 9a, FIG. 10a is a half-cut longitudinal sectional view of the hollow cylinder liner rough material formed by the method of the present invention, FIG. b is a photograph showing the metal structure of the composite interface part of the Y part in Fig. 10a, Fig. 10c
10 is a half-cut vertical cross-sectional view when an embedded composite disk material is used, and FIG. 10 d is a photograph showing the metal structure of the composite interface portion of the Z section in FIG. 10 c. 1... Punch, 2... Die, 3... Stripper, 4... Hollow part, A, B... Material, M... Concentric composite disc material, 11... Ram, 12... Die, 1
3... Container, S... Billet, T... Compound rod, 21, 22... Mold.

Claims (1)

[Claims] 1 Using a concentric composite disc material in which a material with excellent wear resistance is combined into the hollow part of a disc-shaped material that has plastic deformability and a certain degree of wear resistance, a hollow composite cylinder liner raw material is made by extruding a rear container. A method for producing a composite cylinder liner rough material, characterized by molding.