RU2008136C1 - Method of deep boring of fine cylinders - Google Patents

Abstract

FIELD: metal working. SUBSTANCE: cutting tool 3 is installed in the through groove of body 1 on axle 2 perpendicular to the axial plane of the body. Positioned in the body bore is spring-loaded tie 5, whose one end is hinged-joined with tool 3 and the other-with double-arm levers 8; turning axle 9 of the levers are located in body 1. The levers carry weights 11. Due to centrifugal forces the levers turn displacing the tie, which in turn actuates cutting tool 3 placing it in the working position. EFFECT: facilitated procedure. 5 dwg

Description

 The invention relates to metal processing and can be used for processing closed ends in machines operating in an automatic cycle.

 The well-known countersink of the company Erix (Kuznetsov Yu. I., Maslov A. R., Baykov A. N. Tooling for CNC machines. Handbook. M.: Engineering, 1990, Fig. 24, p. 242), in the mandrel of which is mounted a folding tool rotating on an axis parallel to the axis of the mandrel and brought into working or inoperative state under the action of centrifugal forces.

 The disadvantage of the core drill is its low reliability, since the cutter is retracted by the forces of friction upon contact of the cutter with the machined surface during the reverse stroke of the mandrel. With a sufficiently quick removal of the mandrel, it is possible to jam the cutter and break the device.

 Known cutter head containing a movable tool holder, connected by means of a hinged spring-loaded rod with a centrifugal mechanism for mixing it, including the load.

 The disadvantage of this head is the low reliability of the spring removal of the load and the cutter with the tool holder to its original position. With prolonged use of the head in mass production, a spring may weaken, which will lead to a decrease in its durability. This is especially true for large movements of the tool holder, i.e., the processing of thick-walled parts, such as pipes. An increase in spring stiffness with a reserve entails an increase in the mass of the load, which will lead to an increase in the weight (metal consumption) of the head as a whole.

 The purpose of the invention is to create a device for processing closed ends, which provided an increase in its reliability and durability.

 This is achieved by the fact that in the device the centrifugal mechanism is made in the form of a two-shouldered lever, rotatable around an axis located on the ledge of the housing. The load of the calibrated mass is fixed at one end of the lever, the other end of the lever with a groove made in it is pivotally connected to the rod.

 The proposed device due to the rotation of the two shoulders of the lever under its own weight helps the spring to retract the cutting tool into the housing, increasing its durability and reliability of the removal of the cutter.

 In FIG. 1 to 4 show a device; in FIG. 5 is a sequence diagram of its operation in FIG. 5.

 The device consists of a mandrel body 1, in the groove of which a rotary cutting tool 3 is mounted on the axis 2, and its axis 4 is pivotally connected to the rod 5. The latter is installed in the body bore and is preloaded by the force of levers 8 created by the mass of loads 11 and spring 6. Rod 5 s using the axis 7 is pivotally connected to the rotary two-arm levers 8 having axes of rotation 9 located on the protrusions 10 of the housing. At the opposite ends of the levers fixed loads 11 calibrated mass.

 The device operates as follows.

The mandrel body 1 of length L is installed in diameter d in the spindle of the boring head. The rod 5 is in its highest position under the influence of the leverage 8, created by the mass of goods 11 and the spring 6. The rotary cutting tool 3 is located in the housing. After positioning and inserting the mandrel into the pre-drilled hole of the part (d + Δ) (coordinate S _max in Fig. 5), the spindle of the boring head (ω _p ) is turned on. Due to the centrifugal forces acting on loads 11 of mass M, the two shoulders levers 8 are rotated through an angle β, compressing the spring 6 and moving the rod 5 by a distance h, turning the cutting tool into the working position until it stops in the lower wall of the groove of the housing 1 (see Fig. 1 and 2). After that, a quick approach (coordinate S _bp ) and a stroke (S _r.h. ) of the mandrel are carried out.

After standing for cleaning the surface, the mandrel quickly returns to the position with the coordinate S _max, the spindle rotation stops, the thrust under the action of the levers 8 created by the mass of loads 11 and the spring 6 returns to its original position and the cutting tool is rotated and installed in the mandrel body, after which the mandrel returns to its original position.

The relationship of the design parameters of the device with the mass of goods M and the rotation frequency ω _{p is} described by the expression obtained by solving the static equation for the pivot arm:
M = M = K · h · l ₁ · sinβ ₁ / ω $\genfrac{}{}{0ex}{}{\text{2}}{\text{p}}$ L $\genfrac{}{}{0ex}{}{\text{2}}{\text{2}}$ · Cos (β ₁ + β ₂ ), where β ₁ is the angle of inclination of the lever to the axis of the mandrel in the initial position;
β ₂ - the angle of rotation during rotation of the spindle with a frequency ω _p ,
K - spring stiffness;
l ₁ and l ₂ - the length of the corresponding shoulders of the lever.

 This expression allows, for example, to calculate the required mass of goods at a given value of displacement h, spring stiffness K and given design dimensions of the mandrel. (56) Copyright certificate of the USSR N 1242312, cl. B 23 B 29/03, 1986.

Claims (1)

 CUTTER HEAD PRIMARY FOR PROCESSING CLOSED END BODIES, in the body of which a cutting tool is mounted, connected by means of a hinged spring-loaded rod with a centrifugal mechanism made in the form of weights connected to movable elements, characterized in that the movable elements are made in the form of two-arm levers whose rotation axes are located on the body, and pivotally connected to the said rod.

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