RU2424906C1 - Thermal press - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to pressure shaping and may be used in designing small-size presses developing different shaping forces. Thermal press comprises stationary bottom plate and one or two movable plates, extrusion ram, heat carrier or coolant feeder. Top plates are rigidly jointed to bottom plate via vertical columns. Every movable plate incorporates sleeve arrange therein. Columns and sleeves have heat carrier or coolant feed channels and are made from material with shape memory and processed thermo mechanically. Note here that, in feeding heat carrier or coolant in columns and sleeves, their length and ID may be varied. Extrusion ram and sleeve inner surface features mating annular grooves and ledges to allow engagement between extrusion rod and sleeves on feeding coolant into sleeve channels.

EFFECT: higher efficiency and safety.

2 cl, 1 dwg

Description

The present invention relates to the field of high and ultra-high pressures and can be used in the design of new small-sized presses, simple in design, with almost unlimited possibilities for creating a pressing force (limited only by the strength of structural parts) used for deformation of materials in the manufacture of parts, synthesis of new materials , crystals, etc.

At present, various types of presses are used to create high and ultrahigh pressures: hydraulic, mechanical (crank, screw, friction), hydromechanical (see TSB).

The disadvantages of these types of presses are large dimensions, metal consumption, design complexity, the need for complex precision parts.

For example, high-pressure hydraulic presses require powerful pumps, hydraulic cylinders and hydrostations, high pressure pipelines, seals of moving parts, and high precision machining of parts.

There are known presses whose operation is based on the principle of thermal expansion of power elements, for example, a press according to [1], which consists of two plates and long columns connecting them, the lower ends of which are pivotally attached to the lower plate, and the upper ones pass through the slots of the upper plate, they are threaded and nuts are screwed. Alternately heating and cooling the columns, you can tighten the nuts all the time, thus shifting the plates and squeezing the workpiece located between them.

The closest technical solution is the press [2] (prototype), which is a fixed lower beam and two upper movable plates, which are interconnected by vertical columns. The lower ends of the columns are embedded in the lower fixed plate, and the upper ends are embedded in two upper movable steel plates placed one above the other, with the columns embedded in them alternately, so that one is clamped by the lower plate and the next passes through it freely, but clamped by the top plate, etc. in a checkerboard pattern. Through the movable plates on the central axis of the press the press rod is passed, which can be clamped in the upper movable plates. Alternately heating and cooling the columns and, accordingly, alternately clamping the press rod in the movable plates, move it by pressing.

The advantage of this press is the simplicity of the device: oil pumps, cylinders, high-pressure pipelines, and sealing devices are not needed to prevent leakage of working fluid in moving joints.

However, this design has significant drawbacks, namely: a large inertia, the need for significant thermal transitions in the cycles of "heating - cooling" of the power elements. For example, if the power elements are made of steel with an average linear thermal expansion coefficient α of the order of 12 × 10 ^-6 deg ^-1 , then with a length of the power element of 1 m and a thermal difference of 100 ° C, the change in its length will be only 1.2 mm. Hence, to ensure speed (large thermal deformations of power elements), it is necessary to increase their length and the thermal difference of the “heating - cooling” cycle of power elements, which, ultimately, increases the dimensions of the thermal press, its energy consumption, and when heated more than 100 ° C, it increases the risk of the process .

The objective of the invention is to develop the design of the press, developing great effort, the principle of which is based on the thermal deformation of the power elements, but with high speed and small thermal differences in the cycles of "heating - cooling" of the power elements, ensuring the safety of the process.

This problem is solved due to the fact that in the known design of the press, including the lower fixed plate and one or two upper movable plates connected by vertical columns, acting as power elements, a press rod, a coolant and coolant supply device, bushings are located in the movable plates, the latter with columns have channels for input and output of coolant and coolant, and the columns and bushings are made of a material having a shape memory effect, for example, titanium nickelide, which changes its size Xer with a slight change in temperature by 10-15%. The temperature range of the change in shape (size) is only a few tens of degrees (about 27-30 ° C), and when changing the shape of a product from this material develops forces of 30-60 kg / mm ² . On the press rod and the inner surface of the bushings are made the same annular grooves and protrusions.

The columns and bushings of the movable plates of the press are thermomechanically processed so that their shape changes in the range of temperatures safe for humans 30-60 ° C, and when heated to 60 ° C, the columns are extended by 10-15%, and the inner diameter of the hole of the bushings of the movable plates covering the movable rod of the press during heating also increases by 10-15%. When cooled to a temperature below 30 ° C, the reverse process occurs.

The proposed device with one or two movable plates (the best option) is shown in the drawing and includes a lower fixed plate 1, a movable press rod 2, two pairs of columns 3 and 4, which act as power elements, movable plates 5 and 6, rigidly associated with columns 3 and 4, in plates 5 and 6, respectively, bushings 7 and 8, an adjustable stand 9 and a device 10 for supplying coolant and refrigerant, for example, hot and cold water, etc. are placed. Columns 3 and 4 and bushings 7 and 8 made of material with effective channels, for example, from titanium nickelide, in columns 3 and 4, channels 11 and 12 are made for introducing a coolant or refrigerant, and channels 13 and 14, respectively, are made in bushings 7 and 8. Moreover, on the press rod 2 and bushings 7 and 8 respective annular grooves 15 are made, into which protrusions 16 formed in this case on the press rod and the sleeve are included when the latter is cooled. On the stand 9 is the pressed workpiece 17.

The work of a thermal press is as follows:

From the device 10, the coolant is supplied to the channels 13 and 14 of the bushings 7 and 8; the inner diameter of the bushings 7 and 8 increases and the latter, with their protrusions 16 and grooves 15, disengage from the rod 2, then coolant is supplied to the channels 11 and 12 of columns 3 and 4, while columns 3 and 4 are extended (without a press rod) . Next, the workpiece 17 is brought to the press rod 2 with an adjustable stand 9. After this, the pressing process begins. Refrigerant is supplied to the channels 13 of the bushings 7, while the inner diameter of the bushings 7 decreases and it engages with its protrusions 16 and grooves 15 with the corresponding grooves 15 and protrusions 16 on the press rod. Then, through the channels 11, the refrigerant is supplied to the columns 3, the latter, being cooled, are shortened, moving the movable plate 5 with the sleeve 7 down and, accordingly, moving the press rod 2 downwards, the workpiece 17 is pressed. After pressing into the sleeve 7 through the channels 13 the coolant is supplied again and after heating, the sleeve disengages from the press rod and after that the coolant is supplied to column 3 through channels 11 and the movable plate 5 with the sleeve 7 rises. At the same time, the refrigerant is fed into the channels 14 of the sleeve 8, bringing it into engagement with the press rod, after which the refrigerant through the channels 12 is supplied to the columns 4, which, cooling, are shortened and move the press rod 2 down due to its engagement with the sleeve 8 of the movable plate 6, pressing the workpiece 17. Next, the coolant is introduced into the sleeve 8, freeing it from engagement with the press rod, after which the coolant is introduced into the columns 4, which move the movable plate 6 up.

And so the cycles are repeated and the press rod moves in the steps and prepress the workpiece to the desired size.

The advantages of such a press are safety (maximum temperature range 30-60 ° C), speed of action, i.e. the transience of the pressing process, and the creation of large pressing forces (from 30 to 60 kg / mm ² ).

LITERATURE

1. US Patent No. 3287486

2. Auth. St. USSR 264900 (prototype).

Claims (2)

1. A thermal press comprising a lower fixed and one or two upper movable plates rigidly connected to the lower plate by means of a pair of vertical columns, a press rod, a device for supplying a coolant or a refrigerant, characterized in that each movable plate is equipped with a sleeve housed in it, vertical columns and bushings are made with channels for supplying a coolant or a refrigerant from a device for supplying them from a material having a shape memory effect, and are thermomechanically processed to allow for supply channels in their coolant or refrigerant changes respectively the length and inner diameter, wherein the ram and the inner surface of the sleeves are made from mutually corresponding annular grooves and projections for engaging with the ram bushing by being supplied with coolant channels bushings. 2. Thermopress according to claim 1, characterized in that the columns and bushings are made of titanium nickelide.