SU1253731A1 - Unit for pressing articles having stepped cavity - Google Patents

Description

"one

The invention relates to powder metallurgy, in particular, devices for pressing metal powders of a replaceable form.

The aim of the invention is to increase the equal density of the product

Fig. 1 shows the pressing unit in the initial position, the cross section of Fig. 2 shows the mutual position of the punches 1, 9, 12, 13 and the die 4 at the time the upper punch 1 enters the die 4 on the size H (pre-pressing); Fig. 3 shows the moment of location of the punches in the pressing unit relative to each other and the die at the end of the slide stroke.

In the drawings, the following notation is accepted: H is the size characterizing the mutual position of the central punch 13 and the die A (bulk height of the upper part of the compact); Hj is the size that determines the mutual position of the punches 12 and 13 (bulk height of the middle part of the compact); H is the size that determines the mutual position of the punches 9 and 12 (the bulk height of the lower part of the compact); H is the size that determines the mutual position of the punch 9 and the die 4; h, is the size that determines the mutual position of the punches 1 and 13 (the height of the upper part of the compact); h is the size that determines the mutual position of the punches 12 and 13 (the height of the middle part of the pressing); hj is the size that determines the mutual position of the punches 9 and 12 (the height of the lower part of the compact) 4, the size that determines the mutual position of the upper punch 1 and the stopper 2 in the pressing unit; H - size, determining the mutual position of the punch 9 and the matrix 4 "

The pre-compressed unit for pressing articles with a stepped cavity contains the upper punch 1 and the stop 2 mounted on the upper plate 3, the die 4 installed in the mounting hole of the movable plate 5 connected through guide columns to the lower press drive (not shown), the lower plate 6 through prisms 7 is mounted on a press table. An intermediate plate 8 is fixed to the bottom plate through supports (not shown). On the plate 8 is fixed punch 9. Between the fixed plates 6 and 8 are movable plates 10 and 11, on which

a set of lower punches 12 and 13 is installed, on the movable plates 10 and 11, lugs 14 and 15 are fixed, which cooperate with lugs 16,

All slabs of the unit are centered by guide bushings (not shown),

The choice of the ratio of the distance H, and H is determined taking into account the density of the bedded powder and pressing and the pre-pressing ratio; a value of H of 0.26-0.3 N is optimal.

The pressing unit works as follows.

With a press feeder (not shown), the powder material is poured into the chamber formed by the die 4 and the punches 9, 12 and 13. After filling the chamber, the press slide moves downward with the punch 1 fixed on it, stopper 2, plate 3,. The puncheon 1 enters the die 4 on size H, Matrix 4, punches 9, 12 and 13 are at this time still in the initial position (pre-pressing on size H occurs.), Density

 4 pressed compacts with

the density of the powder y is equal to

J iHj. + |) g (H, +,) - Nd

With one-sided pressing, the density is higher on the rolling punch side, therefore, in the lower part of the pressing, the density is lower than the specified value.

With the further progress of the press ram, when limiter 2 is abutted into matrix 4 and sets it in motion,

the die 4 together with the punch 1, the stopper 2, the punches 12 and 13 will move relative to the punch 9 to the stops 16 (final pressing occurs by the punch 9). When the desired pressing pressure is reached, the slide moves up, and the die 4 moves down, releasing the compact. The block operation cycle is completed. Due to the fact that during pre-pressing in the upper part of the pressing the density is equal to the value, and in the lower part this value is less, then at the final pressing there is no redistribution (overflow) of the powder in the radial

312537314

direction from the punch 9 under the punch: iHj. +

Sleep 12 and from the punch 12 Nojot Poin- (H) Sleep 13. Therefore, the density after the windows is such that it is possible to regrow

the pressing of the pressing is the equal-distribution of the powder from the punch 9 under

dimensional height pressing. The punch 12 and from the punch 12 under the puncher 2 does not allow the process 13

pressing the punch 1 into the mat-In connection with this after the final

Ritsu 4 for a larger size than N. Pressing at the bottom of the pressing

At a size greater than H, the density is less than at the top.

overcompaction of the upper part of the press (table 1 and 2),

scoops with pre-press-In table. The values of density are given, which leads to uneven density of the pressing elements when the height of the pressing after the window-press of the press unit without limiter, coherent pressing is worn. With the size, Table 2 shows the values of denser-smaller H, with the preliminary npec-t5. According to the elements of the compactor, when working, popping the value of the press-block with the stopper.

. , one

Work time, min

Density, g / cm Start | -j - 111

10 20 30 40 50 60

Upper part 6.3 6.3 6.4 6.45 6.45 6.44 6.46 Medium 6.3 6.3 6.3 6.34 6.35 6.36 6.35 6.35

Lower part 6,3 6,25 6,15 6,01 6,0 6,05 6,0

Table 2

Work time, min. Beginning .-. ™ ----- ------ -.-------

 102030405060

Upper part6,36,32. 6.31 6.346.35 6.33 6.33

one

Middle section 6.3 6.27 6.29 6.31 6.32 6.3 6.31

Lower part

6.3 6.28 6.29 6.3

6.32 6.31 6.3

FIG. 2

Editor T. Parfenova

Compiled by G, Zagorsk Tehred L. Serdyukova

Order 4665/15 Circulation 757 Subscription

VNIIPI USSR State Committee

for inventions and discoveries I3035, Moscow, Zh-35, Raushsk nab, d. A / 5

Production and printing company, Uzhgorod, st. Project, 4

Proofreader L. Patay

Claims (1)

BLOCK FOR PRESSING PRODUCTS WITH A STEPED CAVITY, containing a matrix, an upper punch, a set of lower punches and intermediate plates with stops placed on them, characterized in that, in order to increase the uniformity of height of the product, the upper punch is equipped with a stopper and the distance between their working ends is selected from the ratio of 0.26-0, ZN ₍ , where H <is the distance to the trader by the upper ends of the matrix and the central lower punch. FIG. 1 & (L a 1253731 A1 12.53