Stamp to restore cross-type knives

 

(57) Abstract:

The invention relates to the repair of production, namely the restoration of worn machine parts, in particular to a device for the recovery of cross knives industrial grinder hot plastic deformation. This stamp contains accommodated in the housing of the composite matrix, the punch and wedges that interact with the location in the body horizontal punches, equipped with outlet springs and stoppers, and eject the part of the matrix interacting with the ejector, and the plug are mated along the radius of the vertical surfaces of the grooves, the protrusions having equal and oppositely directed bevels. Deforming the tabs horizontal punches in the cross section are rounded, the radius of which the magnitude of the horizontal stroke of the punch is determined by the presented dependencies. Stamp allows you to increase the quality of recovery cross-type knives with simultaneous improvement of the structural performance of their cutting edge. 6 Il.

The invention relates to the repair of production, namely the restoration of worn machine parts, in particular to devices Known stamp for repair parts mainly the type of rods, comprising upper and lower plates with mounted on them accordingly punch with wedges, and a matrix made with walls, movable in the direction perpendicular to the axis of the pressure stamp (A. S. N 1250375, MKI 21 J 13/02, bull. N30, 1986). However, the design of the stamp is not possible to recover details of the type of cross knives industrial meat grinder.

Closest to the proposed stamp is a stamp to restore cross-type knives, characterized in that it contains accommodated in the housing compound mimics the shape of the knife a matrix and a punch having a deforming protrusions with bevels, centering mandrel and the ejector (Patent N2103139, MKI 23 P 6/00, bull. N 3, 1998-prototype).

The disadvantage of this stamp is uneven filling of the cutting edges of the recovered knife redistributed stock of metal, while the deformation only in the vertical plane leads to the formation of dead zones and internal voids on the surface of the most important working part of the knife, resulting in decreased performance and durability of repaired products, increasing the proportion of defective forgings, and cutting edge when sharpened "provok with geometrically-complex front surfaces, which significantly reduces the scope of such stamps. To the General lack of serial cross-type knives should be attributed to the low efficiency of the cutting process, since the profile of the blade and the angle of the knife sharpener does not correspond to the optimal settings. Most cross-type knives plane connector stamps coincides with the front surface, forming a bulge.

An object of the invention is the provision of uniformity of filling of metal worn cutting edges of the knife when restoring and improving the quality of the recovered knife with simultaneous improvement of its design.

The task is achieved by the fact that the stamp to restore cross-type knives, containing accommodated in the housing compound that mimics the shape of the knife, a matrix and a punch having a deforming protrusions with bevels, centering mandrel and the ejector equipped accommodated in the housing horizontal punches having deforming the tabs and spring-loaded to it tailrace springs, wedges, established with the opportunity to interact with the said horizontal punches, while deforming the protrusion of each of the horizontal punches at the cutting edge of the knife with regard to the allowance for cutting, mm;

H is the maximum thickness of the rear deformable knife directly at the cutting edge, mm;

the sharpening angle of the knife, appointed from conditions samosatene blade at his work, grad.;

the magnitude of the stroke m of each of the horizontal punches determined from the formula

m = R(1-sin),

the angle of the bevels deforming protrusions of the matrix and the punch is determined from the formula

< / BR>
where S is the width of the cutting edge of a knife, mm;

L1- the length of the cutting part of a knife, mm;

L is the length of the cutting part of a knife, mm;

H1- minimum thickness of the rear part from the backside of the deformable knife, mm;

l0- the width of the back surface of the deformable knife in the middle part, mm

Using the proposed stamp is not only the restoration of the pressure of a worn cutting planes cross knives industrial grinder type MP 200, but also the improvement of their design, namely the execution of the front surface of the blade in cross-section in the form of reverse curves and creation on this basis, self-sharpening cutting edges, providing long-term saving in the wear process of the initial profile of the blade of a knife, then e is eat, in existing designs of stamps to restore cross-type knife pressure is applied only vertical deforming effect, which leads to uneven filling of worn cutting edges of the blades and causes the formation of dead zones on cutting planes refurbished products, additionally, there are no such stamps that simultaneously with the restoration and thermomechanical hardening to improve the design of serial cross-type knives creation of optimum cutting angle, providing samstock during operation. The proposed stamp allows you to restore the cross knives with geometrically-complex front surfaces, for example in the form of a groove.

The originality of the proposed technical solution is to use two-plane deforming action, which provides a more uniform filling of metal worn cutting edges of the knife and increases the intensity of movement of the metal along the planes of shear during hot plastic deformation, which contributes to the process of thermo-mechanical hardening of restored surfaces, reduces the porosity of the alloy and is guaranteed ustroennogo punch creates thereby deepening, has a cross-sectional view of the reverse curves in the shape of an arc of a circle with a sharp sharpening angle relative to the cutting edges, thereby increasing the efficiency of the cutting process and provides samosatene knife during operation. The presence of the wedges allows you to ensure that deformation of the front surface of the recovered knife rounded protrusions horizontal punches, and then back surface sloping ledges vertical punch, which significantly reduces the efforts of the deformation, since the formation process is divided according to two phases. The purpose of the angle counter directed bevels on deforming protrusions matrix and a vertical plunger depending on design parameters recovered the knife and the embedding depth of deforming protrusions horizontal punches also gives an opportunity to significantly reduce of deformation forces and more evenly fill the redistributed metal engraving stamp in areas of wear on the cutting edges.

The invention is illustrated by drawings, where Fig. 1 shows a cross section a-a of the stamp closed up; Fig. 2 - section b-B of Fig. 1; Fig. 3 - brings the CSOs punch (the arrows indicate the direction of flow of metal); in Fig. 5 is a General view of the cross knife after processing in the stamp; Fig. 6 - section G-G of Fig. 5.

In Fig. 1 shows a cross section of the stamp to restore cross-type knives closed up, which contains accommodated in the housing 1 composite matrix 2, the punch 3 and the wedges 4, interacting with located in the housing horizontal punches 5, provided with outlet springs 6 and limiters 7 /Fig. 2/, while the pushing portion 8 of the matrix 2, interacting with the ejector 9 /Fig. 1/, and the punch 3 are conjugate radius r with vertical surfaces CS and BF grooves 10, the protrusions having equal and oppositely directed bevels 11 and 12 /Fig. 3/. Deforming the protrusions 13 of the horizontal punches 5 in cross section are rounding 14, the radius R which is determined by the formula

< / BR>
where h is the height of the cutting edge of the knife with regard to the allowance for cutting, mm;

H is the maximum thickness of the rear deformable knife directly at the cutting edge, mm;

the sharpening angle of the knife, appointed from conditions samosatene blade at his work, hail,

and the value of m horizontal stroke of the punch 5 is determined from the ratio:

m = R(1-sin),

in addition, panocha cutting part of a knife, mm; /Fig. 2/;

L is the length of the cutting part of a knife, mm;

H1- minimum thickness of the rear part from the backside of the deformable knife, mm; /Fig. 3/;

l0- the width of the back surface of the deformable knife in the middle part, mm

The radius R of curvature 14 of the deforming protrusion 13 horizontal punch 5 is selected so that after the displacement of metal from the front surface of the knife 15 formed by the sharpening angle ensured the maximum effect samosatene and high quality cutting. If desired sharpening angle of the knife, of a right-angled triangle ETO, given that the angle TEO equal and THOSE = h + 1/2H, find the radius R of curvature of the deforming protrusion

< / BR>
Then the value of m horizontal stroke of the punch 5 sets of ratios

m = R(1-sin).

The punch 3 and the pushing portion 8 matrix 2 have recesses 10 recoverable under the knife edge 15.

The height t of the compensating wear of the metal that is displaced from the rear outside surface of the knife 15 bevel 12 of the punch 3 is determined from the condition of equality roaming volumes

V1+ V2= Vsymptom- V0,

where V1- the amount of metal transferred from the front surface of a knife, mm3 - the amount of the worn-out metal, mm3;

V0- the size reduction of the cutting edge due to a change in its configuration, mm3.

Since

< / BR>
V2= 1/2tl0L and Vsymptom= ShL,

where R is the radius of the deforming protrusion horizontal punch, mm;

the sharpening angle of the knife, deg;

t - the height of the compensating wear of the metal, mm;

L1- the length of the cutting part of a knife, mm; /Fig. 2/;

L is the length of the cutting part of a knife, mm;

l0- the width of the back surface of the deformable knife in the middle part, mm.

S - width of the cutting edge of a knife, mm; /Fig. 3/;

h - the height of the cutting edge of the knife with regard to the allowance for cutting, mm,

we have:

< / BR>
After transformations we obtain the expression

< / BR>
Where can we find the size of the stroke "m1" punch 3

< / BR>
The optimum angle of inclination of the beveled lugs 11 and 12, allowing to minimize the flow resistance of the redistributed metal under the action of the punch 3 and the pushing portion 8 of the matrix 2, is determined from the rectangular triangle ABM /Fig. 3/, which AM=l0and

< / BR>
After substitution of the expression for t we get:

< / BR>
The presence of the chamfers 11 and 12 on d to reduce the deformation force P1in the vertical plane, which is determined by the formula

< / BR>
where N is the number of cutting elements of a knife;

L is the length of the cutting part of a knife, mm; (Fig. 2);

tthe yield strength of the metal, PA;

l0- the width of the back surface of the deformable knife in the middle part, mm.

secondly, to provide a gradual increase in the contact area between the pushing portion 8 of the matrix 2 and the plug 3 from the rear outside surface of the knife 15 /Fig. 3/, which will increase the uniformity of the filling metal worn cutting edges and will bring the deformation zone to the place wear.

The force of the P2required for deformation of the front surface of the knife 15 horizontal punches 5, is based on constructing the fields of slip lines with the deformation element of the knife is rounded protrusion 13 /Fig. 4/. Slip lines intersect the contact surface EN angle . Designating by the angle between the vertical to the contact surface EN and radius R, held at the point of a section, find the rotation angle of slip lines 18 from point a to point b

< / BR>
moreover, belongs to the interval from 0 to happy, appointed by the sharpening angle of the knife, I am glad.

Then taking into account that P2= Ft(1+aABis ugenia deforming protrusion horizontal punch, mm;

L1- the length of the cutting part of a knife, mm; /Fig.2/.

The concentrations of the recovered knife 15 in the stamp is on the mandrel 16 /Fig. 1/.

Forming elements 2,3,8,5 stamp closed up to form a cavity in cross section having the form located on the axis of symmetry of the isosceles trapezoid ABCD and rectangle FENK, paired with the segment of a circle radius R /Fig. 3/.

The dashed line in Fig. 3 shows the contour 17 of the worn-out knife 15.

Restore cross-type knives in the stamp is as follows. Heated to the temperature 110050oC worn cross knife 15 /Fig. 1/ set the matrix 2, the mandrel 16 to contact with the surface 11 eject part 8 matrix 2 /Fig. 3/. When working stroke of the press wedges 4 interact with the horizontal punches 5, the last rounded protrusions 13 deform the front surface of the knife blade 15 on the value of "m" by moving the metal in the notches 10 provided on the punch 3 and the pushing portion 8 of the matrix 2, and in the space between the beveled lugs 11, 12 and the rear surface of recoverable knife 15 /Fig. 4/. At the end of the horizontal stroke of the punches 5 and complete FM 12 punch 3 rear outside surface of the knife 15 to a depth of t /Fig. 3/, and the metal fills the recess 10 until full compensation of wear of the cutting plane of the knife 15 and the simultaneous creation of allowances for subsequent processing by cutting.

To restore the cross knife industrial grinder type MP 200 and the formation of self-sharpening surface grinding angle equal to 60othe radius R of curvature 14 of the deforming protrusions 13 horizontal punches 5 results of calculations should be 21 mm, the magnitude of the horizontal stroke of the punches 5 m=2.8 mm, the deformation force P2=90 kN, while the angle of the bevels 11, 12, select equal to 8oand the deformation force P1and the magnitude of the stroke m1punch 3, respectively 230 kN and 0.5 mm

The use of two-plane deforming impact enables you to evenly fill the notches 10, avoids the formation of dead zones, internal voids, and other defects, in addition, it enables additional thermomechanical hardening of the cutting edges of the recovered knife 15 and the formation of wear-resistant front surface with a given profile of the blade.

Because the redistribution of reserves compensating wear metal cutting edge, the degree of deformation of the rear surface is reduced in comparison with a vertical scheme of deformation, and therefore, retains strength restored knife.

The formation of the optimal shape of the edge and corner of sharpening the cutting edges of the knife 15 is facilitated by the configuration of the cavity engraving stamp in close position in the form of symmetrical isosceles trapezoid AVSD, quadrangle FENK and it is associated with the segment of a circle radius R

The presence of analytically adjusted the angle of the bevels 11, 12 and ahead of the curve horizontal deforming influence of vertical provide a significant reduction efforts deformation with a corresponding increase in the resistance of die tooling.

After removal of the punch 3 and pins 4, attached to the cross beam press, horizontal punches 5 under the action of springs 6 are assigned to the stop limiter 7 in the die wall 2 /of Fig. 2/, then forged knife is removed from the matrix 2 4 sectional ejector 9 /Fig. 1/.

The stamp can be pertalian to restore cross-type knives with geometrically-complex front surfaces due to mastroyannis composite matrix 2 and the horizontal poinsette technical requirements applicable to serial knifes, thus formed, the front surface 19 /Fig. 6/ with an acute angle sharpening ensures lasting in operation the original shape of the blade and contributes to the stability of the grinding process of the processed product.

Along with improving the quality of recovery of worn-out cross-type knives stamp allows you to improve the configuration of their front surfaces in order to allow the effect of samosatene.

Thus, the use of the invention allows to achieve the following results:

1. Improve recovery cross knife with a simultaneous strengthening of the working surface.

2. Improvement of the structural performance of the front surface of the knife, which gives the effect of samosatene cutting edges during operation of the grinder and the efficiency of cutting.

3. Reduction efforts deformation due to the introduction of analytically adjusted the angle of the bevels on the edges of the matrix and punch, as well as the timing of the horizontal deforming influence of vertical.

4. Extend the effective application of the stamp is P> The realization of the potentialities of the present invention can improve the quality of the repair cross-type knives with simultaneous improvement of the structural performance of their cutting edge.

Stamp to restore cross-type knives, containing accommodated in the housing compound that mimics the shape of the knife a matrix and a punch having a deforming protrusions with bevels, centering mandrel and the piston, characterized in that it has placed in the enclosure horizontal punches having deforming the tabs, and spring-loaded to it tailrace springs, wedges, established with the opportunity to interact with the said horizontal punches, while deforming the protrusion of each of the horizontal punches in cross section is made with a curvature, the radius R is determined by the formula

< / BR>
where h is the height of the cutting edge of the knife with regard to the allowance for cutting, mm;

H is the maximum thickness of the rear deformable knife directly at the cutting edge, mm;

the sharpening angle of the knife, appointed from conditions samosatene blade at his work, hail,

the magnitude of the stroke m of each of the horizontal punches determined from fly

< / BR>
where S is the width of the cutting edge of a knife, mm;

L1- the length of the cutting part of a knife, mm;

L is the length of the cutting part of a knife, mm;

H1- minimum thickness of the rear part from the backside of the deformable knife, mm;

l0- the width of the back surface of the deformable knife in the middle part, mm.

 

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FIELD: metal working.

SUBSTANCE: hard alloy matrix has casing, bushing pressed in the case and hard alloy insertion. Bushing has multifaced hole. Hard alloy insertion is composed by several sections made in form of trapezoidal-section prisms which have cut angles at their non-working edges. Number of sections corresponds to number of faces of item to be headed. Cuts of angles are made symmetrically to faces of working edge. Slits are made in several places of multifaced hole bushing at the ponts where faces cross each other.

EFFECT: improved resistance of matrix; simplified assembly.

3 cl, 1 dwg

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