JPS63313649A - Production of cast-in liner member - Google Patents

Abstract

PURPOSE:To form hardened layer on inner peripheral face of a liner member and to improve quality of a casting by projecting high energy beam on outer peripheral face of the lower member to form recessed part and controlling irradiating energy and interval of irradiating positions. CONSTITUTION:While rotating the liner member 10, the high energy beam 3 is projected, to form the recessed part 12. While controlling the irradiating energy and the interval (l) of the irradiating positions, almost uniform quenching hardened layer is formed in the inner part of the liner member 10. By this method, the liner member having excellent quality can be efficiently formed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method of manufacturing a liner member that is cast into, for example, the cylinder block of an engine. Attempts have been made to form the cylinder block from aluminum or its alloys. In this case, the inner circumferential surface of the cylinder is formed of a liner member made of cast iron, etc., and this is then filled with molten base metal (aluminum or its alloy) during casting, but generally aluminum and iron have good metallurgical properties. Therefore, a problem arises in that the cylinder block body and the liner member are not firmly connected.

To solve this problem, for example, as shown in Japanese Patent Application Laid-Open No. 55-8370, by providing unevenness on the outer peripheral surface of a cast iron sleeve and surrounding it with aluminum alloy,
An invention is disclosed in which the body and the sleeve are mechanically coupled, and according to this invention, a cylinder block in which the block main body (body) and the liner member (sleeve) are firmly coupled can be obtained. Become.

On the other hand, the liner member cast into this type of cylinder block is usually hardened to improve the wear resistance of the inner circumferential surface, which is the sliding surface with the piston ring. A laser beam may be used for this hardening process. In that case, as shown in FIG. 5, a reflecting mirror B is arranged in an inclined manner inside the liner member A, and the laser beam is irradiated from one opening of the liner member A while rotating and moving it in the axial direction. A method is used in which the laser beam C is reflected by the reflecting mirror B to irradiate the entire inner circumferential surface A' of the liner member with the laser beam C, thereby hardening the core portion A' by quenching.

(Problems to be Solved by the Invention) By the way, when the liner member is cast into the base material as described above, in order to mechanically connect them, the outer peripheral surface of the liner member is provided with irregularities, and the inner peripheral surface is When performing hardening treatment to improve the wear resistance of the surface, these two processes must be performed on the outer circumferential surface and the inner circumferential surface, respectively. Therefore, manufacturing this type of liner member becomes extremely troublesome, and the hardening method using a laser beam as shown in FIG. 5 requires a complicated device for driving the reflecting mirror B. Since the reflecting mirror B is damaged early by the energy of the laser beam C, it must be replaced frequently, resulting in a problem of high costs.

In addition, not only when a laser beam is used, but in hardening treatment in general, it is difficult to confirm the hardened state of the surface to be treated, so it is difficult to finish the hardness of the core part to the optimum value, and quality variations are likely to occur. There is a problem.

The present invention addresses the above-mentioned problems when a liner member is cast with molten base metal, such as an aluminum alloy cylinder block. It is possible to easily manufacture a cast liner member in which irregularities are formed, and a quenched hardened layer is formed on the inner circumferential surface for improving wear resistance, etc., and the hardened layer is precisely controlled to the desired hardness. The object of the present invention is to realize a method that allows stable formation.

(Means for Solving the Problems) That is, the method for manufacturing a cast liner member according to the present invention includes forming a recess by irradiating the outer peripheral surface of the liner member with a high-energy beam such as a laser beam or an electron beam. On the other hand, the method is characterized in that a thermal effect caused by this irradiation is exerted on the inner circumferential surface of the liner member to form a quenched hardened layer in the core portion. In this case, the irradiation energy of the high-energy beam to the outer peripheral surface, specifically, the irradiation output, beam scanning speed, etc., and the interval between irradiation positions are controlled so that the cured layer is substantially uniform.

(Function) According to the above configuration, on the outer circumferential surface of the liner member that is directly irradiated with the high-energy beam, the metal structure is partially eluted to form a concave portion, so that the liner member is exposed to the molten base material. When a product such as a cylinder block is cast by casting, the liner member and the base material are mechanically and firmly connected. In addition, during irradiation with the high-energy beam, the thermal influence extends to the inner circumferential surface of the liner member, forming a hardened layer in the core, and the irradiation energy and spacing of irradiation positions are appropriately controlled. Therefore, the hardened layer is formed substantially uniformly on the inner circumferential surface. Therefore, when the inner circumferential surface of the liner member is a sliding surface with a piston ring or the like, good wear resistance can be obtained.

It should be noted that the size of the recess formed on the outer peripheral surface approximately corresponds to the thermal influence on the inner peripheral surface, that is, the quenching and hardening state of the inner peripheral surface, so by observing or detecting the formation state of the recess mentioned above, The hardening state of the inner circumferential surface can be indirectly understood. Therefore, it is possible to control the irradiation output of the high-energy beam and the like while giving feedback so that an optimal hardened layer is formed on the inner circumferential surface.

(Example) Hereinafter, an example of the method for manufacturing a cast liner member according to the present invention will be described.

First, as shown in FIG. 1, a rotating jig 1 and a laser beam irradiation device 2 are used in this method. A liner member 10 made of cast iron is formed in advance on the rotating jig 1.
and drive it to rotate around its axis.
The irradiation device 2 is moved in the axial direction of the liner member 10 while irradiating the outer circumferential surface 11 of the liner member 10 with the laser beam 3 by the irradiation device 2 . As a result, the laser beam 3 is continuously irradiated onto the outer circumferential surface 11 of the liner member 10 in a spiral manner, as shown in FIG.
A part of the metal structure is eluted from the outer circumferential surface 11 of the liner member 10 along the irradiation trajectory, and a spirally continuous recess 1!412 is formed on the surface 11.

At this time, in the metallographic structure of the liner member 10, a hardened layer is formed centering on the groove 12 due to the energy of the laser beam 3, but as shown in FIG. Each groove 12a...1
As a result of the cured layers 2a being centered on each other, a cured layer 14 is formed on the inner circumferential surface 13 of the liner member 10, which is continuous over the entire surface 13. In that case,
The irradiation energy of the laser beam 3 corresponding to the irradiation output of the laser beam 3, the scanning speed of the laser beam 3 depending on the rotation speed of the liner member 10 and the feed speed of the irradiation device 2, and the pitch of the spiral recess 11112, that is, the By appropriately setting the interval η between the grooves 12a .

In this way, by irradiating the outer circumferential surface 11 of the liner member 10 with the laser beam 3 while appropriately controlling the irradiation energy, the interval between the irradiation positions, etc., the grooves 12 are formed on the outer circumferential surface 11. At the same time, a substantially uniform quenched hardened layer 14 can be formed on the inner circumferential surface 13, and if this is used, for example, as a cast member when casting an aluminum cylinder block for an engine,
The liner member 10 is firmly connected to the base material, and the inner circumferential surface 13 exhibits good wear resistance against sliding parts 5 such as piston rings.

Incidentally, since the overall temperature of the liner member 10 gradually increases as time elapses from the start of irradiation with the laser beam 3, it is possible to form grooves 12 of uniform depth throughout the member 10 and to form a uniform hardened layer. 14, it is desirable to gradually reduce the irradiation output of the laser beam 3 from the start of irradiation, or to gradually increase the scanning speed.

Further, the recess formed in the outer circumferential surface 11 of the liner member is not limited to the spiral groove 12 as in the above embodiment, but may be an annular groove 12' as shown in FIG. But that's fine. In either case, by appropriately setting the irradiation energy of the laser beam and the interval between the irradiation positions, a substantially uniform hardened layer can be formed on the inner circumferential surface.

(Effects of the Invention) As described above, according to the method of the present invention, irradiation energy and irradiation position are applied to the outer peripheral surface of a liner member made of cast iron or the like that is cast into a base material made of aluminum or its alloy. Since the high-energy beam is irradiated by appropriately controlling the interval between the two, a concave portion is formed on the outer circumferential surface, and at the same time, a substantially uniform hardened layer is formed on the inner circumferential surface.

Therefore, when used as a liner member for an engine cylinder block, for example, the outer peripheral surface must be processed to strengthen the bond with the base material, and the inner peripheral surface must be improved in wear resistance against sliding of piston rings, etc. processing will be carried out simultaneously and very easily, resulting in a reduction in the cost of this type of liner element. In addition, by observing the state of the recesses formed on the outer circumferential surface, it is possible to grasp the formation state of the quenched hardened layer on the inner circumferential surface, so the hardened layer can be accurately and stably formed to the desired hardness. It becomes possible to do so.

[Brief explanation of the drawing]

Figures 1 to 4 show examples of the method of the present invention, in which Figure 1 is a cross-sectional view showing the state of high-energy beam irradiation, Figure 2 is an external view of a liner member with a recess formed on its outer peripheral surface, FIG. 3 is a partially enlarged cross-sectional view of the liner member showing the state of formation of the quench-hardened layer, and FIG. 4 is an external view of the liner member showing the state of formation of the recess in another embodiment. Furthermore, FIG. 5 is a schematic explanatory diagram of a conventional method for forming a hardened layer on the inner circumferential surface of a liner member. 10...Liner member, 11...Outer peripheral surface, 12°1
2'... Recessed portion, 13... Inner peripheral surface, 14... Quenched hardened layer.

Claims (1)

[Claims] (1) A method for manufacturing a cast liner member that is cast with molten base metal during casting, in which the outer peripheral surface of the liner member is irradiated with a high-energy beam to form a recess, and the irradiation energy and irradiation position are A method for producing a cast liner member, comprising controlling the interval between the liner member and the liner member so that a substantially uniform hardened layer is formed on the inner circumferential surface of the liner member.