SU946801A1 - Apparatus for pressing powder articles - Google Patents

Description

one

The invention relates to powder metallurgy, in particular, devices for pressing products from powder, and can be used in the manufacture of ring cores from hard powders such as carbonic iron, molybdenum permallo, etc.

A device for pressing powder is known, comprising a die, a punch and an ejector.

However, this device does not allow pressing of products with a rounded end surface, and the dimensions of the finished product may have deviations due to the ingress of powder on the ends of the side walls.

Closest to the present invention is a device for pressing powder products, comprising a lower plate, a lower matrix, a punch with a central rod, an upper plate, an upper matrix made of conical sectors with ball sliders, and equipped with an end clamp and a unclamping mechanism, the ejector, located in the annular groove of the upper matrix, and clamps, fastener ejector with the top plate 2.

The device allows pressing products with a rounded end surface, however, when pressing difficult-to-form powders, for example, carbonyl iron powders, molybdenum permallo and some others, high pressure is required (up to 19, (20 tf / sd / Most)). In this case, the yield strength of the steel from which the press tool is made is approached. Therefore, the press tool resistance during the extrusion of articles from the mentioned powders is extremely low.

The purpose of the invention is to increase the durability of the press tool.

The goal is achieved by the device for pressing products from powder 5 containing n (a slab, a lower matrix, a punch installed in it with a central rod, an upper plate, an upper matrix made of conical sectors with ball sliders and equipped with a conical clamp and unclamping mechanism, ejector, located in the annular groove of the upper matrix, and the retainers securing the ejector to the upper plate are provided with a housing and a base rigidly attached to it; the ejector is provided with a through hole m and is provided mounted in the hole and screwed into the base of the adjustment screw and placed on the screw pruzhinoY5 and the central rod is made integral in the form of a cylindrical head, the hollow tsnpindricheskoy parts and springs arranged between them on the screw inserted into the hollow cylindrical part and is screwed into the cylinder head.

FIG. 1 shows the device in the initial position, a general view: FIG. 2 the same in the pressed position; Figure 3 shows the pressing process with a stationary ejector (press device); in fig. - pressing process with floating ejector (proposed device)

The device contains the lower matrix 1, 8 interacting with the punch 2j fixed in the holder 3 ejector c with a through hole 5 and a spring 6o located in it. In the ejector hole h an adjusting screw 7 is mounted movably on the base 8. enclosed in the housing 9. Screw 7 placed in the annular groove 10 of the upper Atrisa 11. By means of the latches 12 13, the take-out device 4 is fixed in the upper plate N. The upper matrix 11 with ball sliders 5 is placed in the cone clamp 16, the end of the groove 10 engages with the shoulder 17 and the housing 9, whereby the position in the outcome matrix 11 holds in podvalennom state. A tapered 16 with an annular spring 18 with grooves 19i e which are fitted with sliders 15 fixed in the holder

20J mounted on the top plate for unclenching is provided with a cam 21, a lever 22 and pushers 23. The lower matrix 1 is fixed on the plate 2h, which, together with the central rod made assembled, is mounted movably on the guides 25 by means of springs 26, the central stitch consists from a cylindrical head 21 acting as a pusher, a spring 28 and a screw 29 movably mounted on a cylindrical part 30 fixed on the crossbar 315 rigidly connected to the plate 24, a pusher is provided for returning to the initial position of the head 27 32, which is driven by a press hydraulic cylinder. The stop 33 limits the movement of the lower matrix up.,

The device works as follows

Claims (1)

In the initial position, a cavity formed by the lower die 1 and the cylindrical head 27, which acts as an ejector, poured the pressed powder. The press drive is turned on and the plate 14 is lowered onto the plates 24, while the upper matrix 11 is placed on the lower matrix 1 and under the action of the springs 26 rises upward along the guide columns 25 relative to the sleeve 20 together with the cone clip 1b. Having reached the moment, the ejector 4 with its end in contact with the end face of the cylindrical head 27., the latter, under the action of the screw 7, begins to descend j causing the spring 28 to compress. Simultaneously with the screw 7, the ejector 4. moves under the action of the spring 65 to take place of the cylindrical With the head 27, the cone clamp 16, moving along the tapered hole of the sleeve 20, compresses the upper matrix 11, eliminating the gaps between sectors. As the plate 14 is further lowered, the springs 26 are compressed, the plate 24 is lowered. At the same time, the cylindrical head 27 continues to be lowered onto the cylindrical part 30 and the pusher 32 returns to its lower position, as shown in FIG. 4. Gradual compaction of the powder occurs. As the pressing force increases, the ejector 4 overcomes the resistance of the springs 28, perematsa up, its rounded surface interlocks with the rounded surface of the matrix 11, the final shaping of the product takes place (Fig. 4). After the forming process is completed, the plate And begins to rise. Upper 11 IniNi 1, the matrices move upward together until the plate 2k comes into contact with the stops 33. The upper matrix 11 separates from the lower one. The pusher 32 returns the cylindrical head 27 to its original position. When lifting the plate 1, the lever 22 comes into contact with the working section of the copier 21 and through the pushers 23 acts on the cone clamp 16, which is displaced downward relative to the holder 20, and its split parts are moved apart from the center to the periphery Simultaneously with the cone the clamp 16 moves downward of the upper matrix 11 and opens it through rigid communication of its sectors through the ball sliders 15. When the upper matrix 11 is opened, the elastic deformations are removed from the pressed product The product moves smoothly along the ejector k, which, under the action of spring 6, returns to its original position. The product is removed from the ejector k by the end part of the forming elements of the upper matrix 11 and remains on the surface of the lower plate 1, since the finished product exceeds the size of the hole diameter in the lower matrix. The rotation of the lever 22 is pumped by coming out of contact with the working section of the copier 21 and the groove torus 10 on the matrix enters the frosting with the collar 17 of the housing 9, the ejector t is located in the torus, and the further displacement of the matrix relative to the ejector ends. The upper matrix 11 is exposed and the ejector 4, together with the plate 14, rises up to its original position. FIG. Figure 3 illustrates the initial moment of compaction of the powder when the ejector does not move. The arrow indicates the direction of pressing, which undergoes a seal of the defect. Since in this case the process of one-sided pressing is carried out, the highest density of the powder is at the end of the pressing punch, the smallest is on the rounded surface of the product (in Fig. 3 the layer of greatest density is shown darker). Pressing the punch moves relative to the die along the pressing axis until the pressing force exerts an equal resistance to the forces of friction of the powder against the walls of the matrix and the cylindrical protrusion of the ejector on the surfaces I and I and the internal friction of the powder grains. Fig. 4 shows the start of compaction for a press case with a floating, movable ejector. At the intermediate and final stages of pressing (Fig. 4), the displacement of the pressing punch takes place with less effort than according to the scheme shown in FIG. 3. This is explained by the fact that in this case the resistance of the friction forces on the outer surface 1 is significantly less than when pressing, according to the first scheme due to the fact that the powder has the ability to flow into the zone P of the ejector having a lower density, since the compaction in zone II is not carried out on a rigid support. There is no resistance to movement of the pressing punch on the surface P, since the ejector moves by compressing the spring together with the punch. The action of friction forces on the surface Iff is also significantly less compared to pressing according to the first scheme, since the movement of the surface of the CG sign occurs in the zone of least compaction, and not the greatest in the first case, with a stationary ejector. The use of a floating ejector allows to obtain an effect that is equivalent to the effect of double-sided pressing, carried out with a pressure of about 2 times less than with a single-sided pressing. For extrusion of products with a rounded surface, two-sided extrusion of hard-to-deform powders cannot be used at all, since the punch that forms the rounded surface in this case must have sharp edges that will be painted and the punches after the first few pressings will go out of order. It should also be noted that the pressing pressure depends on the volume of the powder in the cavity formed by the different positions of the rounded surface of the ejector relative to the rounded surface of the die. It is practically established that the larger the volume of the powder (i.e., the greater the height of the cavity), the less pressing pressure is required. However, the cavity height must be up to TQ% of the height of the finished product. With a greater height, therefore, with a larger volume of powder enclosed in a cavity, there is a noticeable difference in the density of the external and. The inner layers of the product (by adjusting the size of the cavity; by changing its height, it is possible to obtain an optimal pressing pressure. Depending on the plasticity and particle size composition, the pressure decreases in sizes from 0-501 for carbonyl iron products and to 25-30%, for products from molybdenum permallo powder. The technical and economic efficiency of the present invention is determined by a decrease in the pressing pressure. This allows the use of less dimensional presses for pressing, therefore, cheaper presses. with less effort, it reduces power consumption. But the greatest effect is achieved by increasing the durability of the press tool. So, if you press a press ((18-20 Tc / CM jc of the mold before its wear, you can get 100018 800 pieces of suitable products, then at a pressure of 13.72., (1415 tf / cm; -6000-500 pieces. Thus, the decrease in pressure by 2 ° / 0 achieved by the application of the invention increases the durability of the molds by 5-7 times. Device for pressing products from nopOtUKa, containing the bottom plate, the bottom matrix installed in it punch with a central rod, upper plate, upper matrix made of conical sectors with ball sliders and equipped with a conical clip and unclamping mechanism, an ejector located in the annular groove of the upper matrix, and clamps, fastening: (ejector with the upper plate, characterized in that, in order to increase the durability of the press tool, it is supplied. but the casing and the base rigidly bonded to the NIN, the ejector is made with a through hole and is provided with an adjusting screw installed in the hole and screwed into the base and placed on the screw by a spring, and the central rod is made composite in the form of a cylindrical head, a hollow cylindrical part and a spring placed between them on the screw inserted into the hollow cylindrical part and screwed into the cylindrical head. Sources of information. Taken into account in examination 1, USSR Copyright Certificate No., cl. B 28 B 7/10, 1972. 2, USSR Copyright Certificate No. 7536if4, Clo 28 B 3/02, 1978. / 7yffffco fig. 3 a / 7f u yfrTf / 76 np (