RU2207223C2 - Groove milling method - Google Patents

Abstract

FIELD: technological processes in machine engineering, metal cutting tools. SUBSTANCE: method comprises steps of mounting milling cutter on milling mandrel having set of spacing clamping rings whose ends are designed for engaging with ends of milling cutter; in order to enlarge manufacturing possibilities using milling cutter whose height is more than width half of groove and less than width of groove; using spacing clamping rings whose peripheral cutting portion and ends are in the form of turn of screw surface with pitch equal to difference between width of worked groove and height of disc milling cutter. EFFECT: enlarged manufacturing possibilities of method. 5 dwg

Description

 The invention relates to mechanical engineering technology for a metal-cutting tool, in particular for milling, and can be used for processing grooves.

 There is a method of milling the sides of the grooves with a set of milling cutters, which contains a milling mandrel with a set of spacer rings, between which a set of two disk milling cutters is installed, the seating surfaces of which are made with forming along an arc of a circle [1, 2]. The cylindrical surfaces of the spacer clamping rings are made with curvilinear generators and are installed between the spacer rings and a set of disk cutters. The ends of the clamping rings, designed to interact with the ends of the cutters, are made at an angle to the axis of the mandrel, equal in direction and magnitude, which is proportional to the distance between the facing ends of the cutters and the size of their diameter.

 A significant drawback of the known method of milling grooves with a set of milling cutters is that after maximum buckling of the disks during compression of the milling cutters and setting to the maximum width of the bore, it is impossible to restore the original minimum width due to residual deformations and because the planarity of the ends of the milling cutters is violated. Another disadvantage is that with this set of cutters it is impossible to process the bottom part of the groove, which makes the processing process more expensive and forces an additional operation to be introduced.

 The closest analogue of the proposed invention is a known method of milling grooves with a rotating disk mill, in which a mill with a height less than the width of the groove is mounted on a milling mandrel with a set of spacer clamping rings, the ends of which are designed to interact with the ends of the mill (see [3]).

 The objective of the invention is the expansion of technological capabilities by changing the width of the machined grooves when installing the peripheral cutting part of the cutter in the form of a coil of a helical surface and adjusting its pitch.

The problem is solved using the proposed method of milling grooves with a rotating disk mill, in which the mill is mounted on a milling mandrel with a set of spacer clamping rings, and the mill is taken with a height less than the width of the groove, but more than half of it, while the peripheral cutting part of the disk mill is made in the form of a coil a screw surface with a pitch P, in addition, the ends of the spacer clamping rings, designed to interact with the ends of the cutter, are also made in the form of a screw surface with the same step, defined divisible by the formula
P = In _p -In _FR ,
where In _p - the width of the processed groove;
In _fr - the height of the disk cutter.

 Figure 1 presents a diagram of a method of milling a groove and a General view of the cutter with a set of clamping spacer rings; figure 2 - clamping spacer ring with a screw end, side view; figure 3 is also a left view along A in figure 2; in Fig.4 is a scan of the workpiece spacer ring shown in Fig. 2-3; figure 5 is a section along b - B in figure 1.

 The method of milling grooves is implemented using a rotating disk mill (saw), which has some design feature.

The grooving tool contains a milling mandrel 1 with a set of spacer rings 2, between which a disk mill (saw) 3 is installed, the peripheral cutting part of which is made in the form of a coil of a helical surface with a step determined by the formula
P = In _p -In _FR ,
where In _p - the width of the processed groove;
In _fr - the height of the disk cutter.

 This design of a disk cutter (saw) 3 can be obtained by cutting the hub and periphery along the radius and diluting the formed ends by the value of step R.

 Between the spacer rings 2 and the disk cutter 3, spacer clamping rings 4 and 5 are installed on both sides. The ends of the rings, designed to interact with the ends of the cutter, are made in the form of a coil of a screw surface of the same step P.

In FIG. 2 and 3 show the construction of a spacer clamping ring made of a trapezoidal plate, the difference of the bases of which is equal to the step P shown in FIG. 4. Since the cut and divorced disk mill (saw) 3 has elasticity, the final adjustment of the mill to the desired pitch and groove width In _{p is} carried out by spacer clamping rings 4 and 5.

 The proposed method of milling grooves is as follows.

A disk mill (saw) 3 is selected with a height of _{FR fr} not more than the width of the milled groove V _p and not less than 0.5 V _p , i.e.

V _p > V _fr > 0.5 V _p
Adjustment of the cutter 3, cut along the radius and separated by steps P, to the groove width dimension by interchangeable spacer clamping rings 4 and 5. The design rigidity of the cutter with a screw cutting surface is reduced by cutting and spreading the ends into step P. This disadvantage is easily eliminated, for example by increasing the diameter of Dg. spacer clamping rings or fixed connection of the diluted ends of the cutter by spot welding, soldering, etc.

 Compared with a conventional milling cutter operating according to a profile cutting scheme, a tool that implements the proposed method additionally removes the allowance from the side edges in the form of narrow layers normal to the machined bottom surface of the groove. This cutting scheme is called sequential or generator [3].

 The generator circuit is designed to process blanks after forging or stamping, having a crust on the surface.

 The proposed method, carried out using a milling cutter with a helical cutting surface, provides a greater thickness and a smaller width of the cut, which intensifies the process, increases processing productivity and tool life, while not requiring pre-processing of the workpiece and allows milling on the crust.

The method allows to save tool consumption, since a mill with a helical cutting surface has a lower height In _FR compared to a traditional one.

 The proposed method allows the use of a standard tool that requires minimal finishing before operation.

In addition, the existing ability to adjust the tool to the width of the machined groove In _p allows you to reduce the number of passes and processing time.

Example. On a horizontal milling machine mod. 82G is made 6M disk milling cutter groove width B _f = 10 mm, a depth of 6 mm and a length of 250 mm. Processed material - steel 40X with tensile strength σ _in = 700 MN / m ² ; the blank is forged. The groove was machined with a slotted cutter (according to GOST 2679-83) from high-speed steel D _fp = 80 mm, V _fr = 6 mm, d = 22 mm with the number of teeth z = 64.

The cutter is cut in radius with the ends to width _W = 10 mm, with the formation of a helical peripheral cutting surface with a pitch of P = 4 mm and mounted on a milling mandrel with a set of spacer clamping rings in which one end face is made in the form of a helical surface with a step of 4 mm and D _to = 56 mm. Feed per tooth s _z = 0.08 mm / tooth, cutting speed v _fr = 30 m / min (~ 0.5 m / s), spindle speed n = 125 min ^-1 . Minute feed s _m = 320 mm / min.

 The piece time for processing is 1.13 minutes, which is two times more productive compared to traditional milling, carried out in two passes.

 Thus, the proposed method of milling grooves expands technological capabilities by changing the width of the machined grooves when installing the peripheral cutting part of the mill in the form of a coil of a helical surface and adjusting its pitch, increases processing productivity and reduces tool consumption.

Sources of information taken into account
1. SU 1756034, B 23 C 3/28, 1992.

 2. SU 1796359, B 23 C 3/28, 1993.

 3. SU 917963, B 23 C 3/28, 1982.

 4. RODIN P.R. "Metal-cutting tools", Textbook for universities, 3rd ed. reslave. and ext., Kiev: Vishka school. Head Office, 1986, p. 218, 219.

Claims (1)

A method of milling grooves with a rotating disk mill, comprising installing a mill on a milling mandrel with a set of spacer clamping rings, the ends of which are designed to interact with the ends of the mill, characterized in that they use a mill whose height is more than half the width and less than the width of the groove, while the peripheral cutting part and the ends of the spacer clamping rings are made in the form of a coil of a helical surface in increments
P = In _p -In _FR ,
where In _p - the width of the processed groove;
In _fr - the height of the disk cutter.

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