RU2360765C2 - Device for punching from liquid metal of tail cutting tool on die casting machine with horizontal compression box - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention can be used in devices for punching from liquid metal of cutting tool on die casting machines with horizontal compression box. Device contains compression box (1), press mold from mobile and immovable half-molds (10, 14), replaceable brasses (2, 3) with reach-through hole (5), additional brass (9) with salient recess (8) on butt and air duct (11) on its surface. Additional brass is implemented as stepless with reach-through air duct, connected in different sides with shape-generating salient recess and with air duct, communicating with vertical joint of press mold, and its outer diametre is equal to outer diametre of replaceable brasses and it is installed together with replaceable brasses with ability of blanking by travelling half-mold (10) and its change in compression box. Additional brass can be implemented in the form of cylindrical discs with projections and grooves, located in plane of vertical joint of discs diametrically from both sides of each of discs and providing its fixation to each other.

EFFECT: reduction of downtimes at changing of additional brasses and reduction of workload at processing of cutting tool.

2 cl, 4 dwg

Description

The invention relates to foundry and can be used for stamping a tail cutting tool from liquid metal on injection molding machines with a horizontal pressing chamber.

A device is known for pressing metal on an injection molding machine with a horizontal pressing chamber, including a pressing chamber and a mold made in the form of replaceable liners and mounted in a glass of a pressing chamber, while the inner surface of the pressing chamber is made stepwise along with the press liners -forms are installed in steps of a larger diametric size (ed. St. USSR No. 499961, MKI B22D 17/10, decl. 12.03.74, publ. 01.25.1976, BI No. 3).

Among the existing disadvantages of the device, it is necessary to note the limited options for the implementation of the forming cavity, because the liners have a longitudinal connector along the axis of the pressing chamber. The device can be used mainly for feather drills or surgical scalpels.

A chamber for pressing injection molding machines is also known, mainly for stamping from liquid metal castings of ferrous and refractory metals, having a stepwise lengthwise inner surface and a filling window in the wall of a step of a smaller diameter, while an additional filling window is made in the wall of a step of a larger diameter (see Autobahn of the Soviet Union No. 605680, MKI B22D 17/10, declared 12.02.1975, published 05.05.1978, BI No. 17).

Among the significant drawbacks of the device, it is necessary to note the impossibility of quality control of a molded replaceable mold insert, into which steel is then poured into the same pressing chamber for stamping from molten metal, for example a shaped drill (ed. St. USSR No. 605680, figure 1 ... 5).

The manufacture of the mold is combined in one pressing chamber with the manufacture of steel castings. However, the closest analogue adopted by the authors as a prototype is a device for stamping from a liquid metal a tail cutting tool on an injection molding machine with a horizontal pressing chamber, containing a mold in the form of a movable and fixed half-mold, a pressing chamber with a stepped inner surface, interchangeable inserts with a forming cavity installed in the pressing chamber in steps of a larger diameter, while the cavity in interchangeable inserts is made through for forming vostovoy part of the tool, and the mold is provided with an additional liner secured in the movable mold half and having at the end a relief cavity for forming the cutting part of the tool, wherein the upper portion of the cylindrical surface thereof is formed an air passage communicated with a relief cavity and the plane of the die slot; in addition, the additional liner is made of copper or an alloy based on it; or iron-based alloy, or bimetallic - the forming part of the liner is made of an iron-based alloy, and the rest is made of copper or an alloy based on it (RF Patent No. 2075368, MKI B22D 18/02, filed September 25, 1992, publ. March 20, 1997, BI No. 8).

Among the disadvantages of the prototype should be noted the impossibility of quick replacement of the additional liner, which is associated with a halt to the operation of the injection molding machine, since the additional liner is fixed in a movable half mold. This leads to machine downtime. The heat is accumulated mainly in the surface layer of the forming relief cavity and does not have time to be removed inside, because The next heat input follows from the next metal fitting. For brass casting, the average resistance of a steel mold ranges from 3,000 to 5,000 press fittings. For aluminum alloy, the highest mold resistance at the world level is 100 thousand press-fits (J.Valesky Liti kovu pod tlaken. Prague. 1963).

Special studies of various materials were carried out to determine their applicability in the manufacture of brass injection molds. Studies have shown that ceramics are too susceptible to destruction from heat and mechanical shock. Graphite-based materials have insufficient resistance to the corrosive effects of liquid brass. Alloys based on tantalum and niobium have low thermal conductivity and are also too expensive.

A mold made of GE22 material (a metal powder made of pure molybdenum, which is then sintered and pressed) withstood 36 thousand fillings, while the surface quality deteriorated slightly, but edge chipping was noted.

According to the above graph of the roughness of castings of copper alloys on the number of fillings, the surface roughness of the castings remains stable at 2.5 μm (25.4 · 10 ^-6 ) up to 26,000 fillings (cM.Machonis Al-vinA.Precis. Metal, 1968, 26, No. 7, p. 54-56; TOLP EI No. 41, 1968, p. 22-23).

Comparative durability of mold inserts when casting brass in C.T. (cycles heat exchange) steel N13 (4X5 MFS) 6000.

Ceramic-metal alloy:

tungsten 20,000;

molybdenum 28,000.

I.I. Goryunov. Injection molds. Reference manual. L .: Engineering, 1973, p. 135.

The task at hand is to increase the productivity of injection molding machines by reducing downtime associated with the replacement of additional forming inserts with a relief internal cavity, and reducing the amount of work involved in cutting the manufactured cutting tool.

This is achieved by the fact that the device for stamping from a liquid metal of a tail cutting tool on an injection molding machine with a horizontal pressing chamber comprises a mold in the form of a movable and fixed half-mold, a pressing chamber with a stepped inner surface, interchangeable inserts with a through inner cavity for forming a tail parts of the tool installed in the pressing chamber in a step of a larger diametric size, an additional insert having a relief cavity for shaping at the end the cutting part of the tool, and in the upper part of its cylindrical surface there is a blind ventilation channel communicated with its embossed cavity and the vertical plane of the mold connector, the difference being that the additional insert is made of quick-change, stepless with a through ventilation channel on its cylindrical the surface connected on the one hand with the forming relief cavity, and on the other hand with the ventilation channel in the mold connector, and the additional liner is made out the same diameter equal to the outer diameter of the interchangeable liners, is installed together with the mentioned interchangeable liners with the possibility of locking and quick replacement in the pressing chamber by the next liners after pushing the casting and returning the pressing plunger to its original position, or the additional liner is made in the form of two cylindrical disks connected between protrusions and mating grooves located in the plane of the vertical disk connector diametrically on both sides of each of the disks, ensuring matches halves of mold cavities zatylovannyh cutter teeth and fixing them relative to one another.

Among the well-known technical solutions, objects of a similar purpose, containing distinctive features from the prototype, were not found, and therefore, the claimed technical solution has novelty. The significance of the differences lies in the fact that the casting is separated from the shells outside the injection molding machine, and the next set of shells is fed into the pressing chamber after the casting is pushed out together with the shells and the pressing plunger returns to its original position. This solution allows you to carefully monitor the forming inserts and to timely replace them until the next press-fit of the molten metal, preventing the quality of castings (roughness and precision of manufacturing of the tool). Observing a certain sequence of installation of sets in the pressing chamber, favorable conditions for the operation of the mold are created.

If between the two fillings the interval necessary to reduce thermal stresses is possible, then crack cracks in the mold can be completely eliminated (see V.M. Plyatsky. Stamping from liquid metal. Publishing House. Engineering. M.L., 1964, p. 255).

The proposed technical solution is illustrated by drawings, which show:

figure 1 - a device for stamping from liquid metal tail cutting tool on a die casting machine with a horizontal pressing chamber;

figure 2 is the same for milling cutters with a backed cutting teeth;

figure 3 is the same; an additional insert for milling cutters with a backed cutting teeth (FIG. 2, item 21);

figure 4 is the same; an additional insert for milling cutters with a backed cutting teeth (Fig.2, pos.22).

A device for stamping from liquid metal on an injection molding machine with a horizontal pressing chamber includes a pressing chamber 1 with a stepwise lengthwise inner surface, a mold in the form of interchangeable liners 2 and 3 installed in a step 4 of a larger diametrical cup size of the pressing chamber 1. In interchangeable inserts 2 and 3, a through hole 5 is provided, located in the insert connector and forming the tail portion 6 of the cutting tool 7. The shaped relief cavity 8 of the cutting part of the tool 7 is made in the end part of the additional insert 9, which is locked by a movable half-mold 10. In the upper part of the cylindrical surface additional liner 9 made the ventilation channel 11, in communication with the vertical connector of the mold. Figure 1 shows: a fixed plate 12 of an injection molding machine, a mold holder 13, on which a movable half-mold 10 is fixed, a fixed plate 14 of a mold, a filling window 15, a pressing plunger 16, a dosed portion of the cast metal 17. The arrow 18 denotes a conical the surface of the interchangeable liners 2 and 3, which serves to ensure separation of the liners from the casting, and the ventilation duct 19.

Figure 2 shows the casting of a cutting tool 7 with a press residue 20.

Figure 2 ... 4 shows a device with an additional liner in the form of two disks 21 and 22, interconnected by protrusions 23 and 24 and mating grooves 25 and 26 located diametrically on both sides of each of the disks in the plane of the disk connector to ensure that the halves of the forming cavities of the backed teeth 27 and 28 of the cutter. Ventilation of the mold cavity is provided by ventilation ducts 29, 30 and 31.

The operation of the device is as follows.

After installing the removable liners 2 and 3 in the step 4 of the larger diametrical size of the glass of the pressing chamber 1, fixed by means of the fixed plate 14 on the fixed plate 12 of the injection molding machine, the additional liner 9 is installed and the mold is closed, with the additional liner 9 and interchangeable the liners 2 and 3 are locked by a movable half-mold 10, mounted on the mold holder 13. Through the filling hole 15, a metered portion of molten metal 17 is fed into the glass 17. The pressing plunger 16, moving left, presses the molten metal 17 through the hole 5, into the shape-forming relief cavity 8, from which air and gases are removed through the ventilation channels 11 and 19 in the mold connector. After exposure to the hardening of the casting, the movable half-mold 10 is moved to the extreme left position, while the pressing plunger 16, while continuing to move to the left, pushes the casting with the tail part 6 and the press residue 20 (FIG. 2) from the pressing chamber 1. After separating the casting from the forming inserts 2, 3 and 9, which is greatly facilitated by the presence of a conical surface 18, and returning the pressing plunger 16 to the extreme right position, the next removable inserts 2, 3 and the additional insert 9 are installed in the glass of the pressing chamber 1, and the cycle operations repeated.

Similarly, a milling cutter is made with backed teeth, which are formed in the shaping cavities of the teeth 27-28 in an additional insert in the form of two disks 21 and 22, fixed relative to each other by the protrusions 23-24 and the response grooves 25-26, while the protrusion 24 of the disk 22 is included the response groove 25 of the disk 21, and the protrusion 23 is included in the response groove 26 of the disk 22. After installing removable inserts 2-3 in the pressing chamber 1 (Fig. 1), an additional insert is assembled in the form of two disks 21-22 and the movable half-mold 10 is locked pressing chamber 1, and the cycle of operations is carried out It works the same way as with the optional insert 9.

The removal of air and gases from the working cavity of the mold is made through the ventilation channels 29-30-31. After cutting off the press residue 20 and separating the casting from the inserts, a shank (for example, steel 45) is welded to the resulting cutting tool (if required), from which the Morse taper is machined or a cylindrical shank from a cast billet is machined.

Thus, the proposed device not only solves the task - increasing the productivity of injection molding machines and reducing the amount of work involved in cutting the manufactured cutting tool, but also expands the range of manufactured cutting tools - milling cutters with backed teeth associated with large losses in the chips of expensive tool steel , losses of electricity, losses associated with the wear of a tool for processing a tool intended for processing grooves shaped o or the profile of a part rounded over the radius of the cross section (see V.A. Korolev, P.M. Zotov, L.S. Margolin. Toolkeeper's reference book. Publishing House Belarus. Minsk. 1976, p. 269, tab. .136). The casting crust of each cutter tooth has increased wear resistance, despite sharpening, along the front edge of the teeth of the cutting tool.

The tail cutting tool allows the use of an electric drill as a drive.

Claims (2)

1. A device for stamping from a liquid metal of a tail cutting tool on an injection molding machine with a horizontal pressing chamber, comprising a mold with a movable and fixed half-molds, a pressing chamber with a stepwise lengthwise inner surface, interchangeable inserts with a through cavity for shaping the tail portion tools installed in the pressing chamber in a step of a larger diametric size, and an additional liner, on the end part of which a relief cavity is made for I shaping the cutting part of the tool, and in the upper part of its cylindrical surface there is a ventilation channel communicated with a relief cavity and a vertical mold connector, characterized in that the additional insert is stepless, and the ventilation channel on its cylindrical surface is made through and connected to one sides with a forming relief cavity, and on the other hand, with a ventilation channel in communication with the vertical mold connector, with an additional liner made from the outside with a diameter equal to the outer diameter of the interchangeable liners, is installed together with the mentioned interchangeable liners with the possibility of locking them with a movable half-mold and quick replacement in the pressing chamber by regular liners after pushing the casting. 2. The device according to claim 1, characterized in that the additional liner is made in the form of two cylindrical disks connected by protrusions and mating grooves located in the plane of the vertical disk connector diametrically on both sides of each of the disks, ensuring the matching of the halves of the forming cavities of the backed teeth milling cutters and fixing them relative to each other.

Images