RU2090339C1 - Method for machining spherical end surfaces of rodlike products - Google Patents

Abstract

FIELD: automatic machining of surfaces of rodlike products. SUBSTANCE: method involves machining part surfaces with end portion of rotary tubular tool; rotating part relative to axis positioned perpendicular to tool rotation axis, with both axes intersecting in center of spherical surface; positioning axis of part and axis of tool in plane perpendicular to axis of rotation of part; positioning axis of rotation of part at predetermined distance from cutting edge of working surface of tool. Value of mentioned distance depends on radius of spherical surface and diameter of tool cutting edge and may be determined by formula recited in Specifications. EFFECT: increased efficiency and improved quality of machined surface. 3 dwg

Description

 The present invention relates to the field of metalworking, namely the formation of spherical surfaces of rod products, such as pushers, caps and other machine parts.

 A known method of processing spherical surfaces (see, for example, ed. St. N 1094671, class B 23 V 5/40), in which the workpiece is rotated around its axis, and the tool, such as a cutter, is rotated using a special device with a rotating barrel at some angle around the axis passing through the center of the processed sphere. Previously, the cutter is gradually brought to the product until its top reaches the axis of the centers of the machines.

 The disadvantage of manufacturing spherical surfaces in a known manner is the need to create special rotary devices for universal machines. Due to the need for turning the tool, these devices have low rigidity. The accuracy of the geometric shape of the processed spheres largely depends on the amount of play in the axis support, on which the table rotates with a tool holder and a tool fixed in it. There is no possibility of continuity and automation of the process.

 A known method of processing spherical surfaces of products, which is the prototype of the proposed solution (see ed. St. N 514681, class B 24 B 11/00), devoid of these drawbacks, in which the processing is carried out by the end spherical surface of the tubular tool. In this case, the axes of the workpiece and the tubular tool intersect in the center of the spherical surface. In addition, the axis of the workpiece is placed at a certain angle to the axis of circular rotation and is additionally rotated around its own axis. This increases the accuracy and productivity of processing and allows you to automate the process.

 However, the known method has significant disadvantages. It is necessary to position the product at an angle to the axis of circular rotation and additionally rotate it around its own axis. This greatly complicates the design of the used devices for implementing the method. It is necessary to perform the end working surface of the tool of a spherical shape. If for a tool in the form of a grinding cup, this is relatively easy to accomplish by diamond dressing it, then for blade tools it significantly complicates their design, since it requires the location of cutting edges on a spherical surface. These shortcomings complicate the adjustment of the processing process and reduce productivity.

,
где
R радиус обрабатываемой сферической поверхности,
D диаметр режущей кромки инструмента ≥ диаметру обрабатываемого стержня.To increase labor productivity and the possibility of automating the processing of spherical end surfaces of rod products has been made possible by using a method in which the product is rotated about an axis perpendicular to the axis of rotation of a cylindrical tubular tool with an end working surface from the condition that the axes intersect at the center of the spherical surface, and the axis products and the axis of rotation of the tool are placed in a plane perpendicular to the axis of rotation of the tool, with p the distance between the cutting edge of the working surface of the tool and the axis of rotation of the product is selected by the formula

,
Where
R is the radius of the machined spherical surface,
D diameter of the cutting edge of the tool ≥ diameter of the workpiece.

,
где
R радиус обрабатываемой сферической поверхности,
D диаметр режущей кромки инструмента.In FIG. 1 shows a diagram of the proposed method for processing spherical end surfaces of rod products. To implement the proposed method, a rod product with a spherical end surface of radius R is rotated about an axis passing through the center O _{1 of the} treated sphere. This axis is perpendicular to the axis of rotation O ₂ O _{2 of the} cylindrical tubular tool having an end working surface. The axis of the tubular tool also passes through the center O _{1 of the} machined sphere. The axis of the product O ₃ O ₃ and the axis of rotation O ₂ O _{2 of the} tool are located in a plane perpendicular to the axis of rotation of the product. The cutting edge of the working surface of the tool is located at a distance L from the axis of rotation of the product. The distance L is selected by the formula

,
Where
R is the radius of the machined spherical surface,
D is the diameter of the cutting edge of the tool.

 The diameter of the tool must be greater than or equal to the diameter of the core of the workpiece D ≥ d.

 As a cylindrical tubular tool, a cutter head, an end mill, or a grinding wheel having the shape of a cylindrical cup can be used. When used as a grinding wheel tool, diameter D corresponds to the inside diameter of the wheel.

The product is informed about the rotation around the axis O ₁ with a frequency of n ₁ , and the instrument around its axis O ₂ O ₂ with a frequency of n ₂ .

 As a result of two rotational movements of the cutting movement made by the cutting tool and the running movement performed during rotation of the product, the processed surface of the product is obtained in an ideal spherical shape.

 The frequency of rotation of the product is less than the frequency of rotation of the tool. The smaller their ratio, the smaller the surface roughness of the treated sphere.

 If the known method for processing spherical surfaces uses three movements of the rotational movement of the tool and the product and the additional rotation of the product around its own axis, then the proposed method requires only two rotational movements of the product and the tool around mutually perpendicular axes. This greatly simplifies both the processing process and the design of the device for its implementation.

 The proposed method, unlike the known one, does not require giving the end working part of the tool a spherical shape. This simplifies the design of the tool and its operation, increasing processing productivity.

 At the same time, the proposed method provides, as is known, the continuity of the process, creating the possibility of easy automation.

 In contrast to the known, the proposed method for processing spherical end surfaces can be successfully performed on universal machines, for example, turning. In this case, the tool is installed in the spindle of the machine, and the fixture with the products installed in it on the support of the machine. Rotation to the workpiece is transmitted from the support of the machine using gears.

 The following is an example showing that the use of the proposed method when processing spherical surfaces of the pushers makes it easy to automate the processing process.

To implement the proposed method use (see Fig. 2) the rotor 1, rotating around the axis O ₁ O ₁ with a frequency of n ₁ . Radial holes are made in the rotor, into which the processed pushers are installed. The figures show the installation of two such pushers 2 and 3. Pushers in the radial holes of the rotor are installed so that their machined surfaces are located at a distance from its axis equal to the radius R of the machined spherical surface. Pushers are installed manually or automatically, using a drive 4 with pusher blanks 5 placed in it and a rammer 6 moving reciprocally and associated with the rotation of the rotor.

Perpendicular to the axis of the rotor in the plane of rotation of the axes of the pushers set the axis O ₂ O _{2 of the} cylindrical tool 7 with the end working part, rotating with a frequency of n ₂ .

 The working end face of the tool 8 is placed at a distance L from the axis of the rotor. The rotor and tool are informed of the rotation around its axes.

 The fastening and unfastening of the processed pushers in the radial holes of the rotating rotor is carried out automatically by lever mechanisms driven by means of copiers. The figures show one of the possible options for copying the machined pushers using a two-shouldered lever 9 mounted in the rotor on the axis 10. The clamping pressure on the lever shoulders is carried out through balls or rollers 11 from a spring-loaded copier 12 located in the rack 13 of the housing in which it rotates rotor (not shown). The pressure on the arms of the lever, and therefore, the fastening force of the pusher being processed, is determined by the stiffness of the spring 14. The compression of the spring is regulated by the nut 15. In the position shown in FIG. 2, the right end of the two-arm lever is raised, and the pusher blank 3 is freely mounted in the radial hole.

 At the same time, the pusher blank 2, which is located in an adjacent radial hole, is securely fixed to the left lowered end of the two-shouldered lever. At this time, it is processed with a cutting tool.

When the rotor rotates 90 ^o in the direction of rotation (see figure 3), the right end of the two shoulders of the lever 9 falls under the action of the copier 12, clamping the installed workpiece 3 of the pusher, and when approaching the tool it is securely fixed.

At the same time, the left end of the two-shouldered lever rises under the action of the copier, freeing the already processed workpiece 2. Under the influence of its own weight, it falls on the receiving tray 16, and from it into the container. After turning the rotor to the next 90 ^{o the} process is repeated.

Claims (1)

A method of processing the spherical end surfaces of rod products, in which the product is rotated about an axis perpendicular to the axis of rotation of the cylindrical tubular tool with the end working surface from the condition of intersection of the mentioned axes in the center of the spherical surface, characterized in that the axis of the product and the axis of rotation of the tool are placed in a plane, perpendicular to the axis of rotation of the product, while the distance between the cutting edge of the working surface of the tool and the axis of rotation of the product t according to the formula

where R is the radius of the processed spherical surface;
D the diameter of the cutting edge of the tool is greater than or equal to the diameter of the workpiece.

Images