RU2685935C1 - Piston rings workpieces manufacturing method - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method includes introduction of metered volume of molten metal into central hole of multi-seat casting block and hardening of workpieces. Robotic complex (RC) is used, containing continuously rotating centrifugal unit with vertical axis, on spindle of which cylindrical receiver is fixed with holes, with balancing and shutoff devices, robot with rotary gripper, accelerating and brake tables, vessel with molten metal, manipulator and periodically moving conveyor. Wherein multi-cavity casting block is pressed into steel barrel with holes on cylindrical part to be heated in furnace to 200 °C and delivered to RC, fixing the barrel in the rotor gripper of the robot, spinning it on the accelerating table and installing into the receiver, dosed volume of molten metal is fed into the central hole of the casting block by means of a manipulator. After solidification of workpieces, the receiver is cooled down with water-based liquid by sprayed compressed air, the barrel is removed from the receiver by means of a robot, its rotation is stopped on brake table and barrel is placed in asbestos cement container located on periodically moving conveyor. At that, after preset time, which can be equal to 1 hour, foundry block is pressed out of barrel, obtained workpieces are subjected to shot blasting and runner system elements are removed.

EFFECT: higher quality of workpieces of piston rings, reduced labor intensity and prime cost of their production.

1 cl

Description

The invention relates to mechanical engineering, in particular, to the production of piston rings for internal combustion engines. The most productive method of manufacturing piston ring blanks is centrifugal casting. However, due to the complexity of manufacturing the shaped profiles of the outer and inner surfaces of the rings, this method is most often used for the manufacture of oil. The latter are cylindrical sleeves. They are cut into separate blanks and subjected to mechanical processing, which is characterized by increased complexity.

The known method of centrifugal casting of piston ring blanks (Patent SU 1694334. Authors: Vainer M.I., Sakhnovsky V.E., Bulaevskaya M.Ya. Class IPC: B22D 13/04. Published 11/30/1991. Copyright Holder: "Odessa Design technological institute for piston rings ". Access mode http: www.findpatent.ru). This method is the closest to the claimed and selected as a prototype.

Among the disadvantages of this method include the low accuracy of the blanks and the increased complexity of their manufacture.

The alleged invention allows to reduce the cost of manufacturing piston rings by reducing the complexity of the machining of workpieces: eliminates the operation of copy turning-boring blanks, significantly reduces the complexity of the operation of grinding the ends

The technical objectives of the claimed invention are: improving the quality of the piston ring blanks, increasing the reliability and stability of the technological processes of their manufacture, reducing the labor intensity and cost of manufacturing one blank, increasing the reliability and durability of the equipment.

The technical result of the claimed invention is achieved due to the fact that the billet piston rings are made on a robotic complex (RTK). All technological processes at the RTK are controlled by a numerical control unit (CNC) device. Details of casting molds are processed with diamond tools at five-coordinate machining centers (OC), and the programs for them are adjusted according to the measurement results of the obtained castings on the measuring machine.

The essence of the claimed invention is as follows. Piston ring blanks are cast on RTK. Its equipment: centrifugal installation, a robot with a rotating tong, accelerating and brake tables, a container with a melt, a manipulator, a periodically moving conveyor.

The vertical spindle of the centrifugal unit rotates continuously. Its bearings cool and lubricate the air-oil mixture. A cylindrical receiver with holes is attached to the spindle. In the upper and lower parts of it have devices for automatic balancing. They are made in the form of closed cavities filled with viscous engine oil and bearing balls. The latter occupy about 2/3 of the cavity volume. In the receiver also install the locking device that secures the glass. Inside the glass with holes, a multi-part casting block is pressed in, containing up to 30 molds.

Each mold consists of a half-form, the working surfaces of which form the lower end and side surfaces of the piston ring billet, and the base of the upper half-form. Last draws the upper end of the workpiece. In the manufacture of half-molds, three slots (gating channels) are extruded on their bases. The height and width of the grooves decrease as they get closer to the workpiece. The half-form consists of two parts: basic and auxiliary. They are made according to the usual technology - they are pressed from fine-grained quartz sand and a binder, and then they are sintered.

In contrast to the known methods, both parts after sintering process (grind or grind) with diamond tools at the OC. They are glued with hot melt to the satellites and fixed on the OC. When machining the base part, they first grind its outer cylindrical surface, all internal and end surfaces draw a control risk with a diamond needle. Then the end of the diamond wheel grind the base on which the gating channels are pressed out. Similarly processed auxiliary item. The base part is pressed into the technological mandrel. Put a binder. Combine the risks and press the auxiliary part into the base. The assembled mold is sent to the oven. After polymerization of the binder, the finished mold is pressed out of the mandrel and controlled.

An additional increase in the accuracy of castings is achieved due to the fact that the programs for the OC are adjusted several times according to the results of measurements of the obtained castings on the measuring machine.

The final assembly of casting blocks is carried out in interchangeable glasses. To reduce the imbalance, the molds in the glass are arranged in a spiral, turning each of them relative to the previous one through an angle of 360 ° / number of blanks in the casting block. The upper part of the block is a funnel. It is made from the same material using a similar technology. On its basis there are also three gating channels. At the base of the funnel and all half-forms, except the first, put a binder. The collected glass is placed in the oven.

The production of a batch of blanks at the RTK (full cycle) is as follows. The glass with the casting block is heated in a furnace to 200 ° C and delivered to the RTK on a periodically moving conveyor. The robot removes it from the conveyor, spins on the stage and installs it in the receiver. The manipulator introduces the metered volume of the melt through a funnel into the central hole of the casting block. After solidification of the metal in the working part of the mold, the areas for placing the blanks are cooled with a spray of compressed air water-based liquid, for example, a three percent solution of soda ash. After quenching and cooling the workpieces to a temperature of 50 ° C, the robot spins its tong on the acceleration table, takes the cup out of the receiver, sets it in the asbestos-cement container, which is on the conveyor, and closes it with a lid.

The melt in the central part of the casting block does not have time to harden. Due to the release of heat, tempering of castings occurs. Changing the diameter of the central hole in the casting block, set the specified time for the release of blanks.

The manufacture of identical blanks at the RTK is performed by the flow method. In serial production for each batch of blanks set their program in the CNC. In the manufacture of billet piston rings of a smaller diameter in the receiver set adapter sleeves. In the manufacture of blanks with a diameter greater than permissible install a new receiver. Centrifugal installation is equipped with several replaceable receivers to ensure processing of the entire range of piston rings manufactured at the enterprise.

Claims (2)

1. A method of manufacturing piston ring blanks by centrifugal casting, including the introduction of a dosed volume of molten metal into the central hole of a multi-unit casting block and solidification of blanks, characterized in that they use a robotic complex (RTK) containing a continuously rotating centrifugal unit with a vertical axis, on which spindle is attached cylindrical receiver with holes, with balancing and locking devices, a robot with a rotating tong, accelerating and brake tables, capacity with molten metal, a manipulator and a periodically moving conveyor, while a multi-position casting unit is pressed into a steel cup with holes on the cylindrical part, which is heated in the furnace to 200 ° C and delivered to the RTC, fix the cup in the rotating bracket of the robot, unwind it on the acceleration table and install the metered volume of molten metal into the receiver in the receiver, inject it into the central hole of the casting block with the aid of the manipulator, and after solidification of the workpieces, the receiver is cooled with sprayed compressed air using a water-based fluid, remove the cup from the receiver by means of a robot, stop its rotation on the brake table and place the cup in an asbestos-cement container on a periodically moving conveyor, and after a specified time, the casting unit is pressed out of the cup, the resulting blanks are subjected to shot blasting and remove the elements gating system. 2. The method according to p. 1, characterized in that the time after which the casting unit is pressed out of the glass, set to 1 hour.