JP3151729U - Rods such as piston rods and welding overlays thereof - Google Patents

Abstract

A piston rod that wears by reciprocating up and down in a cylinder and a crankcase together with a piston of a crosshead type diesel engine or the like is made by machining the outer peripheral surface of the rod to have a small diameter and a different diameter. Without causing surface peeling, the compatibility with other cylinders can be maintained, quality can be maintained sufficiently, and the piston rod has been repaired so as to improve durability, and the weld overlay used for that purpose. I will provide a. Carbon steel forged steel is used in which a welding metal 4 for welding build-up is coated on the outer peripheral sliding surface of a rod 1 such as a piston rod that is used in a sliding state and wears on the sliding surface. Products and machine structural carbon steel steel rods are welded to the outer peripheral sliding surfaces of the rods to cover the required weld overlay. [Selection] Figure 1

Description

  The present invention relates to a rod such as a piston rod of a ship crosshead type diesel engine or the like and a weld overlay apparatus thereof in the field of repairing mechanical elements.

  In a crosshead type diesel engine or the like, a piston rod is connected to a lower part of a piston, and reciprocates up and down in the cylinder and the crankcase together with the piston. A packing box is installed at the boundary between the cylinder case and the crankcase to prevent the combustion products from the explosion from entering the crankcase.

  However, the packing of this packing box wears the outer peripheral surface of the piston rod, and finally the sealing effect is lost, and combustion products from the explosion in the cylinder enter the crankcase, deteriorating the lubricating oil of the engine and lubricating it. It could endure use as an oil or, in the worst case, could lead to a fire in the crank.

Therefore, the rod outer peripheral surface of the piston rod that has reached the wear limit is rectified, and the piston rod and the packing of the packing box are made to have a small diameter and a different diameter so as to continue use.
Yes.

  However, in this case, compatibility with other cylinders is lost, and maintenance management becomes complicated. In addition, the repair cost becomes enormous, and there is a limit to the dimensions that can be repaired for piston rods of different diameters. Furthermore, although repair by thermal spraying is also conceivable, there are cases in which surface layer peeling occurs during use, and there are problems such as lack of reliability.

  The present invention has been made in view of the above points, and in order to solve the above-described problems, the present invention is used in an outer peripheral sliding surface of a rod such as a piston rod which is used in a sliding state and wears on the sliding surface. The present invention provides a rod such as a piston rod, which is coated with a required weld metal for welding overlay.

  In addition, welding is performed on the outer peripheral sliding surfaces of rods of carbon steel forged products (JIS-G3201 and the same) and carbon steel materials for machine structures (JIS-G4051 and the same) to cover the required weld overlay welding metal. It provides rods such as piston rods that have been repaired.

  Further, a preheat temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to a predetermined carbon equivalent Ceq (%) on the outer peripheral sliding surface of a piston rod of a crosshead type diesel engine or the like that has been worn out by a predetermined amount. Pre-heat the rod to be welded, coat the welded outer welded metal on the outer peripheral sliding surface of the worn rod, and heat-treat at 350 to 400 ° C x 1.5 to 2.0 hours after welding. In addition, a rod such as a piston rod that has been repaired by heating and cooling for about 10 hours is provided.

  Further, a preheat temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to a predetermined carbon equivalent Ceq (%) on the outer peripheral sliding surface of a piston rod of a crosshead type diesel engine or the like that has been worn out by a predetermined amount. The rod to be welded is preheated, and the outer peripheral sliding surface of the worn rod is covered with a weld metal for welding overlay repair. After welding, the rod is heated to a temperature of 500 to 600 ° C. The present invention provides a rod such as a piston rod that has been repaired by performing a heat treatment in which the temperature is lowered at 30 to 80 ° C./h over each stage and held at each stage for 1 hour or more.

  Furthermore, when the sliding surface is worn, the sliding surface is worn and the outer peripheral sliding surface is covered with the required welding metal for welding overlay, and the rod such as a piston rod is leveled to the swivel device. In addition to being arranged so as to be rotatable at a rotational speed, a carriage is arranged so as to run parallel to the upper surface of the rod at a predetermined speed with the welding nozzle facing the upper surface of the outer peripheral sliding surface of the horizontal rod. One or a plurality of preheating burners are arranged in front of the rod welding nozzle and welded at a preheating temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to the carbon equivalent Ceq (%). Providing a rod welding and overlaying device for piston rods, etc., characterized in that the rod to be built up is preheated and the outer peripheral sliding surface of the worn rod is covered with a weld metal for welding overlay repair by welding It is.

  Furthermore, the present invention provides a rod welding build-up device such as a piston rod that detects the temperature of the upper surface of the rod with a temperature sensor and adjusts the amount of preheating of one or more preheating burners.

  A rod such as a piston rod of the present invention is a weld metal for welding build-up required on the outer peripheral sliding surface of a rod such as a piston rod that is used in a sliding state and wears on the sliding surface as in claim 1. By covering the cylinder, compatibility with other cylinders can be maintained, maintenance can be easily managed, repair costs can be reduced, piston rods can be repaired multiple times, surface peeling does not occur, and quality Can be sufficiently retained, and durability can be improved.

  Further, as described in claim 2, the welding is performed on the outer peripheral sliding surface of the rod of the carbon steel forged product or the carbon steel material for mechanical structure, and the above-described welding metal is covered and repaired. So that effective repairs can be made.

  Furthermore, the preheating temperature PT (° C.) = Ceq × K (K) with respect to a predetermined carbon equivalent Ceq (%) on the outer peripheral sliding surface of the piston rod of a crosshead type diesel engine or the like worn as in claim 3. = 350 to 500) Preheating the rod to be welded and welding the outer peripheral sliding surface of the worn rod with a weld metal for welding overlay repair, and 350 to 400 ° C x 1.5 to 1.5 after welding By performing a heat treatment of 2.0 hours, and further repairing by maintaining the temperature for about 10 hours, the piston rod of a crosshead type diesel engine or the like can be repaired with high durability as described above.

  Furthermore, the preheating temperature PT (° C.) = Ceq × K (K) with respect to a predetermined carbon equivalent Ceq (%) on the outer peripheral sliding surface of a piston rod of a crosshead type diesel engine or the like worn as in claim 4. = 350 to 500) Preheat the rod to be welded, and cover the outer peripheral sliding surface of the worn rod with a weld metal for welding overlay repair. After welding, the rod is heated to a temperature of 500 to 600 ° C. For high-carbon carbon steel forgings and machine structures by heating and then repairing them by performing heat treatment that lowers the temperature at 30 to 80 ° C / h over multiple stages and maintains each stage for 1 hour or more. It is possible to effectively prevent stress removal and cold cracking of the carbon steel rod, and as described above, it is possible to repair the piston rod of a crosshead type diesel engine or the like with high durability.

  Furthermore, the rod such as a piston rod that is used in a sliding state as in claim 5 and wears on the sliding surface and covers the outer peripheral sliding surface with the required welding metal for welding overlay is leveled. The swiveling device is rotatably arranged at a predetermined rotational speed, and the welding nozzle is opposed to the upper surface of the outer peripheral sliding surface of the horizontal rod so that it can run parallel to the upper surface of the rod at a predetermined speed. And a preheating temperature PT (° C.) = Ceq × K (K = K = with respect to the carbon equivalent Ceq (%) by disposing one or more preheating burners in front of the rod welding nozzle. 350 to 500), the rod that is welded is preheated, and the outer peripheral sliding surface of the worn rod is coated with the weld metal for welding overlay repair by welding. A piston rod or other lock that causes wear on the moving surface. The piston rod of such a cross-head diesel engine the outer peripheral sliding surface can preheated to the required preheating temperature uniform shape without causing cold cracking, it can be repaired good durability.

  Furthermore, as described in claim 6, by detecting the temperature of the upper surface of the rod with a temperature sensor and adjusting the preheating amount of one or more preheating burners, the outer peripheral sliding surface of a rod such as a piston rod can be adjusted. It can be preheated uniformly to the required preheating temperature and repaired with good durability as described above.

The side view of the piston rod of the crosshead type diesel engine of one example of the present invention, Outline explanatory diagram of weld overlay repair of the same submerged arc welding equipment, Outline processing explanatory diagram of heat treatment after welding overlay as above, Sectional drawing for preheating description of the rod welding overlay repair of another Example same as the above.

  The rod of the present invention, such as a piston rod, and its welding build-up device are used in a sliding state, and wear occurs on the sliding surface. It is characterized by covering with metal.

  As shown in FIG. 1, the piston rod 1 slides on the outer peripheral surface of the piston rod of a crosshead type diesel engine used in a ship or the like, or the packing or bushing of a piston rod of a forging hydraulic press, injection molding device, or the like. It can be applied to those that are worn and reused. As its material must be durable under heavy loads and severe use conditions, it can be applied to carbon steel forgings and carbon steel materials for machine structures that have a relatively large diameter and deserve reuse. is there.

  For example, when a piston rod 1 having a diameter of 100 to 500 mm and a length of 1000 to 4000 mm of a crosshead type diesel engine used in a ship or the like is used for 3 to 5 years, the outer peripheral sliding surface of the rod 1 is 1 It wears out by about 4 mm, and it causes trouble to use continuously. Therefore, in order to overhaul, the piston head 2 is removed as shown in FIG. 2, and the roughed base processing piston rod 1 is rotatably mounted in a horizontal state on a welding device 3 such as a submerged arc to weld the required weld metal 4. Overlay, cover and repair.

  As the piston rod 1, for carbon steel forgings and carbon steel materials for machine structures, those containing chemical components C, Si, Mn, P, S, Cr, Mo in the corresponding weld metal material are used. For example, for carbon steel forgings such as SF490A and SF590A and carbon steel materials for mechanical structures such as S45C and S55C, the weld metal material is G50 / US-511 JIS-Z3183 S641-1CM or G80 / US-511 JIS-Z3183 S641- Required products such as 1CM (both Kobe Steel products) can be used in accordance with JIS-Z3183 S641-1CM.

In addition, for example, overlay welding by a welding device 3 such as a submerged arc is performed with respect to the carbon equivalent that is repaired by covering the outer peripheral sliding surface of the rod 1 with the weld metal 4 of the above-described weld overlay repair in one layer or multiple layers. (%) = C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15 (1)
Preheating temperature of rod 1 for welding overlay PT (° C.) = Ceq × K (K = 350 to 500) (2) Preheat the rod 1 for welding overlay. A heat treatment at 350 to 400 ° C. × 1.5 to 2.0 Hr is performed after welding, and a heat insulation and cooling treatment is performed for about 10 hours in a heat insulating material immediately after the heat treatment.

  As preheating of the welding device 3 such as a submerged arc, the piston rod 1 is mounted on the horizontal roller 5 as shown in FIG. 2, one end is mounted on the swiveling device 6, and a preheating burner is provided on the front side of the welding nozzle 7. One or more heating means 8 such as heaters or heaters are arranged opposite to the surface of the rod 1 through an expansion / contraction device or the like at regular intervals, etc., and mounted on the carriage 9 so that it can be driven at a required speed. The heat adjustment can be performed so as to maintain the above-described preheating temperature relatively corresponding to the feed amount of the welding nozzle 7.

  Further, as another heat treatment after overlay welding of the rod 1, the temperature of the rod 1 is raised to a temperature of 500 to 600 ° C. in a heat treatment furnace such as an electric furnace as shown in FIG. It is possible to reduce the temperature at 30 to 80 ° C./h over multiple stages and repair by carrying out heat treatment that keeps the temperature at each stage for 1 hour or more. It is possible to remove the stress of rods of carbon steel forgings and carbon steels for machine structures, increase the uniform slow cooling effect of the weld metal and HAZ part, make the structure uniform, and effectively remove the causes of cold cracks, etc. Can be. The heat treatment over several stages to several tens of stages can be appropriately determined according to the material, diameter, length, etc. of the rod 1, and the temperature is lowered at 30 to 80 ° C./h for 1 hour or longer, preferably Is preferably maintained for 2 to 4 hours for stress relief and homogenization of the structure of the weld metal and the HAZ part.

  Further, as shown in FIG. 4, it is preferable that the heat retaining cylinder 10 such as a heat-resistant bellows is covered around the piston rod 1 to be welded so that the heating means 8 can save energy.

  In this way, it is understood that cold cracking can be prevented and stress can be removed by performing the required preheating temperature and heat treatment corresponding to the carbon equivalent of the treated material. The piston rod can be repaired twice, the surface layer does not peel off, the quality can be maintained sufficiently, and the durability can be improved.

Table 1 is a chemical composition table of the piston rod 1 of the crosshead type diesel engine according to one embodiment of the present invention.
Table 1 Chemical composition table of piston rod

Table 2 is a chemical composition table of the weld metal of overlay welding by the welding apparatus 3 corresponding to Table 1 above.
Table 2 Example of chemical composition of welding rod of overlay welding rod

  As shown in FIG. 2, the repair by the welding device 3 is performed by removing the piston 2 and mounting the piston rod 1 which has been subjected to a predetermined roughing process on the horizontal roller 5 and mounting one end on the swivel device 6 and rotating at a constant rotational speed. A plurality of heating means 8 of a preheating burner are arranged on the front side of the welding nozzle 7 so as to face the surface of the rod 1 at a predetermined interval, and are preheated to the above preheating temperature. Then, the amount of feeding of the welding nozzle 7 is adjusted so as to perform overlay welding. The welding apparatus 3 used alternating current arc current, and was performed by automatic welding downward, single pass, welding current 400-420A, welding voltage 30-35V, welding speed about 58 cm / min.

  As the welding apparatus 3, the carbon equivalent of the rod 1 to be welded is heated at a preheating temperature of 180 to 250 ° C. based on the Ceq of the above formula (1), and the required welding rod described above is applied to the welding nozzle 7; Flux welding material is supplied, and the surface temperature of the rod 1 is measured with a surface thermometer 11 to confirm the preheating temperature, and the SF 590A, 300 mm diameter, 3000 mm length of the piston rod 1 is worn on the outer peripheral sliding surface. One layer of weld metal 4 was coated. And it heat-processed 350-400 degreeC * 1.5-2.0Hr after welding build-up, and about 10Hr heat insulation cooling was performed in the heat insulating material immediately after the heat treatment.

  As a heat treatment after build-up welding, the rod 1 is heated to a temperature of about 580 ° C. as shown in FIG. 3, then cooled to 70 ° C./h, lowered to a temperature of about 510 ° C. and held for 3 hours. In addition, it can be cooled at 80 ° C./h, lowered to a temperature of about 430 ° C. and held for 3 hours, further cooled at 80 ° C./h and held at a temperature of 350 ° C. for 3 hours. The heat treatment is performed in three stages and then gradually cooled to effectively prevent the stress removal of the rod and the low-temperature cracking due to the welding overlay.

  After welding overlaying, heat treatment was performed as described above, heat insulation and cooling were performed, finish polishing was performed with a predetermined accuracy, and appearance inspection and nondestructive inspection were performed to produce a product. As a result, there was no cold cracking, the appearance and the internal condition were good, and the quality could be sufficiently guaranteed.

  Although the submerged arc welding apparatus 3 has been described above, it can also be applied to covered arc welding, TIG welding, carbon dioxide arc welding, plasma arc welding, and the like, and the piston rod 1 is made of high carbon steel of carbon steel forgings. However, the present invention can also be applied to high carbon steels for machine structural carbon steel. Further, not only the repaired product but also a new product if necessary, the outer circumferential surface of the piston rod can be preliminarily welded and finished as described above to improve the durability.

  The piston rod of the present invention and its weld build-up device are worn out by sliding the outer peripheral surface of the rod with the above-described crosshead type diesel engine piston rod, packing or bushing of the piston rod of a forging hydraulic press, injection molding device, etc. And can be used for re-used items.

    DESCRIPTION OF SYMBOLS 1 ... Piston rod 2 ... Piston head 3 ... Welding device 4 ... Weld metal

Claims (6)

A rod, such as a piston rod, which is used in a sliding state and is coated with a required welding metal for welding build-up on the outer peripheral sliding surface of the rod, such as a piston rod, which causes wear on the sliding surface. The rod such as a piston rod according to claim 1, wherein the outer peripheral sliding surface of the rod of carbon steel forged steel or carbon steel for machine structure is welded and covered with a weld metal of a required weld overlay. A welded meat with a preheating temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to a predetermined carbon equivalent Ceq (%) on an outer peripheral sliding surface of a piston rod of a crosshead type diesel engine or the like worn out by a predetermined amount. Preheat the rod to be built up, coat the welded metal for welding overlay repair on the outer peripheral sliding surface of the worn rod, and perform heat treatment at 350 to 400 ° C. × 1.5 to 2.0 Hr after welding buildup, Furthermore, rods, such as a piston rod of Claim 2, which carried out repair by carrying out about 10Hr heat insulation slow cooling. A welded meat with a preheating temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to a predetermined carbon equivalent Ceq (%) on an outer peripheral sliding surface of a piston rod of a crosshead type diesel engine or the like worn out by a predetermined amount. The rod to be built up is preheated, and the outer peripheral sliding surface of the worn rod is covered with a weld metal for welding overlay repair. After welding, the rod is heated to a temperature of 500 to 600 ° C. The rod such as a piston rod according to claim 1 or 2, which has been repaired by performing a heat treatment in which the temperature is lowered at 30 to 80 ° C / h and maintained at each stage for 1 hour or more. When used in a sliding state, the sliding surface is worn and the outer peripheral sliding surface is covered with the required welding metal for welding overlay, and the rod such as a piston rod is leveled to the swivel device at a predetermined rotational speed. The rod is disposed rotatably, and a carriage is disposed in parallel with the upper surface of the rod at a predetermined speed so that the welding nozzle faces the upper surface of the outer peripheral sliding surface of the horizontal rod. One or a plurality of preheating burners are disposed in front of the welding nozzles of the steel, and welding is performed at a preheating temperature PT (° C.) = Ceq × K (K = 350 to 500) with respect to the carbon equivalent Ceq (%). A rod welding build-up device, such as a piston rod, characterized in that the rod is preheated and the welded metal for welding build-up repair is coated on the outer peripheral sliding surface of the worn rod by welding. 6. A rod welding and building apparatus for a piston rod or the like according to claim 5, wherein the temperature of the upper surface of the rod is detected by a temperature sensor to adjust the amount of preheating of one or more preheating burners.

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