SU1289605A1 - Apparatus for continuous pressing of elongated articles from powder - Google Patents

Abstract

The invention relates to devices for the continuous pressing of long articles from powder. The purpose of the invention is the expansion of technological capabilities by forming articles of a wider range of densities. The screw 4, through the gear wheel 6, receives rotation from the drive and moves the powder from the hopper 14 to the stepped chamber formed by the sleeve 3, the outer cup 2, the mandrel 9 and the inner cup 10. From the hydraulic cylinder 8 through the rod 7, the nut 13 and the cover 12 is created backwater Kryppka 12 is removed and the powder is extruded. The step chamber has molding zones (A), compaction (B) and calibration (C), and the length of zone B is chosen from the condition O: F - 5 / (D + d), where D is vyyt {Enny diameter of the cup 2; d is the outer diameter of the cup 10. Since the length of zone B can vary when moving the component parts forming the stepped chamber, the force of friction can also vary, which allows changing the density of products within five limits (reducing its lower limit when extruding plasticized mixtures and increase the upper limit during extrusion of low- and non-plasticized powders). 1 dw., 4 tab. С i (Л 6 5 ND 00 О5 СД Ю П 12 / Л

Description

one

The invention relates to

powder metal device, in particular, for you to continuously press HOMepFibix products made of powder materials.

The purpose of the invention is the expansion of technological capabilities by forming articles of a wider range of densities.

The drawing shows the device, General view, longitudinal section.

The device comprises a housing, an outer cup 2, installed with the possibility of axial alternation, and a sleeve 289

ay 3, inside of which a screw 4 is placed, a lug 5 is attached to the end of the body. The hollow auger is connected to a drive (not shown) by means of a gear wheel 6. A rod 7 is mounted inside the auger connected to a hydraulic cylinder 8. On the rod is mounted; , mating on a cylindrical surface with an inner cup 10, installed with the possibility of axial movement and connected to the rod by means of a nut 11. On the rod is fixed 12 by means of a nut 13 On the case there is a loading hopper 14. The sleeve, mandrel, outer and. inner glasses form a stepped chamber; The indicated chamber contains three zones A zone - forming, zone B - sealing, zone C - calibrating. The length Z of the compaction zone is determined by the conditions

About .E ..

where D is the inner diameter of the outer glass;

d is the outer diameter of the inner cup.

If the length 2 is equal to O, the product and splitting appear on the product due to the difference in tangential stresses along the outer and inner surfaces of the material being extruded. When the value of I is greater than the limiting value, the forces of friction increase significantly, which makes it impossible to extrude the product, I

The device works as follows.

Auger 4 through a gear wheel 6 receives rotation from the drive and moves the powder from the hopper 4 to the stepped chamber. Cover 12 closes the exit from the specified chamber. From hydrocyligadra 8 through

-

ten

 ,

20

25

96052

the rod 7, the nut 13 and the cover 12 provide the support necessary to achieve the desired density. The KpbiiUKa is then removed and the powder is extruded into a tubular product. At the same time, in the forming zone (zone A) of the stepped chamber, the product is molded in the form of a tubular billet, the required density is achieved in the sealing zone (zone B), and the final dimensions of the finished product are obtained in the calibrating zone (zone C). the sealing zone is filled with powder. Since the coefficient of friction of powder over powder is greater than that of powder on the smooth steel surface of a stepped chamber, the force of friction in the sealing zone also increases. The greater the force of friction, the greater the force needed to advance the powder. As is known, the density of compacts depends on the pressure of the press bar. Since the length of the sealing zone E may change as the components move, forming a stepped chamber, a change in the frictional force is possible. The latter allows smoothly varying the density of products over a wide range regardless of the material being extruded.

In addition to this, under the action of the elastic deflection forces at the entrance to the sealing zone, there is an increase in the size of the extruded product, which

35 causes shear deformations in the radial direction. In this zone, friction against the chamber walls leads to shear deformations in the axial direction. At the exit from the compaction zone, the size of the product is reduced to the specified ones, which leads to shear deformations in the radial direction. The intense shear of the particles relative to each other in the sealing zone contributes to a more dense packing of the powder particles.

Tables 1-4 show comparative data on the density of products obtained through the known and proposed devices, with different contents of plasticizer.

thirty

40

45

55

If the mixture contains a smaller amount of plasticizer, then it is impossible to obtain the product in a known device, since a plug forms in the conical part of the matrix.

rotka, containing corg: ch oon 5, pressure member and oir.chg. rod, about those with a view that, with the aim of expanding technological capabilities of them through a wider range of products 5, it is provided with a sleeve covering the pressing member, onp with a stepped outer surface, placed on the rod after the pressing member, with an outer section, covering the sleeve, and an inner cup, conjugated with (rub, while the glasses made with a version in the bottom and installed with the possibility of axial movement The sleeves, sleeve, mandrel, and glasses are installed to form a stretch center with forming areas, sealed 1 or 20 calibrations, and the length of the sealing area is determined by

five

D + d

f5

ABOUT

R

As follows from the table below, the proposed device, in contrast to H3BecTf oro, at small values of 1 and x of value F ensures the production of less dense products. This is due to the fact that in the known device the powder is crimped in the radial direction in the tapered part of the matrix. At the same time, even if the amount of reduction is small, the density will be 6–7% higher than when extruded per pass. The upper density value (50%) is the same for both devices, since with a density density the maximum possible particle packing is for a mixture with a given plasticizer content.

Thus, the proposed device allows expanding the density control range of products by reducing the lower limit by 6-7% while extruding plasticized mixtures and increasing the upper limit by 36-44% when manufacturing products from little and not plasticized, where D is the inside diameter of the outer powders of his cup;

Claims (1)

Claim d - outer diameter inner Device for continuous press glass; The length of long products from G is the length of the compaction zone.  a b and c a 1 Device p,% of the density of a compact material at 6 mm O 30 60 I 90 I 120 I150 I 180 I 200 Known 27 27 32 39 42 46 50 50 Proposed 20 21 27 34 39 44 50 50 Note: The content of the plasticizer - ПЖЗМЗ + 12% paraffin; E is the distance from the screw end to the die in the known device and the length of the stepped chamber in the proposed device. table 2 Device p,% of the density of a compact material at t, mm About I 30 I 60 I 90 I 120 150 180 Weights;} You are not extruded ProposedTre- 24 37 49 59 71 86 women Note: The content of the plasticizer - ПЖЗМЗ + 8% pa rafipa. rotka, containing corg: ch-unk 5, pressure member and air.hg. chnp rod, which is designed to expand technological capabilities of a wider range of densities 5, it is provided with a sleeve enclosing the pressing body, onpai with a stepped outer surface placed on the rod after the pressing body, an external glass enclosing the sleeve, and an internal glass adjacent to (trace, the glasses being made with a hole in the bottom and installed with the possibility of an axle th movement, sleeve, and the mandrel cups ustanovle-, us to form stug.enchltoy ry with zones molding uplotn1 -No sizing and 20, and the length of sealing area is determined from the condition five D + d f5 ABOUT R  where D is the inner diameter of the outer glass; Device is about,% of the density of a compact material at 2 mm O 30 I 60 I 90 120 I 150 Known Not Extruded The proposed Tre- 29 44 57 69 91 women Note: The content of the plasticizer - ПЖЗМЗ + + 3% paraffin. Table 4 Device p,% of the density of a compact material with i, mm O 30 60 I 90 I120 I 150 Known Not Extruded Proposed27 34 46 60 74 94 Note: The content of the plasticizer ПЖЗМЗ + + 0% paraffin. Compiled by G. Zagorsk Editor N. Slobod nickname Tehred N. Gluttsenko Proofreader I. Korol Order 7847/1 Circulation 763 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4 Table 3