RU2294258C2 - Rolling unit - Google Patents

Abstract

FIELD: plastic working of metals, possibly expanding tubes in tube walls.

SUBSTANCE: rolling unit includes separating housing; cone expanding rollers having rolling bands, head end portion and tail end portion; windows for mounting them; spindle passing along axis of housing. Said windows are formed on separating housing uniformly along its perimeter with central angle 120° between adjacent windows whose axes are turned by predetermined angle relative to generatrix of housing. Said windows are arranged in lengthwise rows, three different-length windows in each row. Boundary windows of lengthwise rows of housing in each row and rollers mounted in them also have different length values. Length values of rolling bands of rollers and distance between rolling bands are determined according to relations given in specification. Total length of rolling band used for expanding is equal to summed length value of rolling bands of all three rollers in window of any lengthwise row and doubled distance between rolling bands of rollers in adjacent windows of each row.

EFFECT: enhanced effectiveness of works for making heat exchange equipment.

4 dwg

Description

The invention relates to the processing of metals by pressure and can be used for flaring pipes in pipe sheets in the manufacture of heat exchangers for various fields of technology.

и рабочим диаметром веретена

в месте их контакта по достижении заданной степени развальцовки. Оно должно быть в пределах

или в среднем в пределах 0,7-0,9. Конусность роликов, как правило, в два раза меньше конусности веретена: для роликов 1:40-1:80, для веретена 1:20-1:40 (Е.И.Юзик. Развальцовка труб в судовых теплообменных аппаратах. Л.: Судостроение, 1978. с.51-58).Rollers containing a cage-separator with windows for accommodating conical milling rollers made uniformly along the perimeter along the perimeter with a rotation of the axis of the latter at a given angle to the said generatrix in a plane tangent to them, the actual milling rollers installed in the said case windows, and a spindle passing along the axis of the body is known in the art. Rolling for the distribution of the pipe installed in the hole of the tube sheet is inserted into the tube until the sleeve fixed on the roll rolling body into the surface of the tube sheet, providing a predetermined position of the rolling belt in the tube within the tube sheet. Then, the spindle is moved along the axis of the housing, spreading the rollers until a reliable grip occurs between the pipe, rollers and the spindle. Then turn on the spindle rotation drive. Due to the rotation of the axes of rotation of the rollers relative to the generatrix of the separator body and the axis of the spindle under the action of friction, the spindle is automatically further extended (self-tightening) and the diameter of the location of the rollers increases - the pipe is expanded. The angle of rotation of the axis of the rollers (γ) determines the speed of the spindle and, therefore, the speed of expansion. To increase productivity, they strive to take the rotation angle of the rollers large (within the range of 0 ° 30'-4.0 °), however, the load on the roller increases, bending forces increase and the roller resistance decreases. As the spindle self-tightens, the torque increases on the shaft of its rotation drive, which, when using an electric rotation drive, simplifies constant monitoring of the change in the torque value and allows to automatically limit its increase in excess of a predetermined value when the required degree of distribution is achieved and to prevent premature destruction of the rolling elements, increase reliability and durability in operation. Such self-tightening rolling is very widespread. To improve the performance of rolling and increase the durability in operation, the ratio between the average diameter of the roller is of great importance

and spindle working diameter

in the place of their contact upon reaching the specified degree of expansion. It must be within

or an average of 0.7-0.9. The taper of the rollers, as a rule, is two times less than the taper of the spindle: for rollers 1: 40-1: 80, for the spindle 1: 20-1: 40 (E.I. Yuzik. Pipe expansion in ship heat exchangers. L .: Shipbuilding , 1978. p. 51-58).

The positive features of such rolling include the possibility of rolling pipes from almost all materials used in heat exchangers, simplicity of design and a fairly high speed of rolling. Pipes are deformed by rollers simultaneously on the entire section of the rolling belt.

To make rolling joints with pipes of small internal diameter, for example, less than 13 mm, with the necessary length of the rolling belt more than 30-40 mm, it is not possible to design rolling of sufficient strength even in the case of adjusting (limiting) the torque. Therefore, rolling joints with a ratio of the total length of the rolling belt to the optimal working length of the roller more than 1.0 (with a large tube sheet thickness) is performed in successive sections with a length shorter than the working length of the roller, in several transitions with overlapping rolling sections to ensure the necessary density of joints. This is one of the significant drawbacks of rolling of the considered type, since it limits the productivity of work and increases their complexity.

This drawback is partially eliminated by the well-known self-tightening rolling, the design feature of which is that it is equipped with an additional (along the perimeter of the housing) row of cylindrical rollers having a diameter equal to the largest diameter of the main tapered rollers and placed in the separator windows made in front of the windows of the main row of tapered rollers in the spaces between them with a partial mutual overlap of the end sections of the rolling belt of the rollers in the specified rows.

This rolling can be considered as the closest analogue of the claimed - its prototype - in technical essence and in the achieved effect (increase in the total length of the rolling belt).

The design features of the considered known rolling determine some of the features of its work. So, after the rotational motion is communicated to the spindle, it begins to “be pulled” by a series of conical rollers due to the rotation of the axes of the latter by a certain angle relative to the axis of the spindle - as in the previously known rolling. In the process of "self-tightening" the spindle moves in the axial direction, pushing the conical and cylindrical rollers in the radial direction and deforming the pipe. Moreover, the cylindrical rollers begin to deform the pipe at first with its end, partially overlapping the rolling belts of the main conical rollers, and then during the distribution of the pipe when the spindle moves, the width of the contact line of the cylindrical rollers with the pipe surface continuously increases until the cylindrical rollers begin to deform the pipe with its entire length. At this point, the flaring process is stopped, the spindle is informed to rotate in the opposite direction, and the rolling is removed from the pipe. Setting the axis of the cylindrical rollers parallel to the axis of the spindle ensures a smooth change in the deformation of the pipe (contact stresses at the interface between the pipe and the tube sheet) from the required minimum values at the pipe exit to the heat exchange cavity to the maximum values in the zone of partial mutual overlapping of the rolling belts of cylindrical and conical rollers throughout the length of the latter.

In this case, the longitudinal axis of the windows of the separator housing for installing additional milling rollers are parallel to the longitudinal axis of the housing and the axis of the spindle (see ed. St. USSR No. 1459778, IPC V 21 D 39/06, 1987).

At the same time, in the text of the description of the invention for the considered rolling, the rationale for increasing the reliability of the rolling joints by increasing their vibration-resistant strength, which is indicated as the purpose of the invention, is not given at all. This allows you to doubt the achievement of this goal in the implementation of rolling according to the specified invention. And although the noted rolling does provide a larger overall length of the rolling belt compared to the previously described rolling, it is not without some other disadvantages:

- insufficient strength and reliability in operation of the housing for rolling pipes with an outer diameter of 20 mm or less due to a strong decrease in the area of the "live" section of the housing in the area of mutual overlapping of the rolling belt of the rollers;

- a slight increase in the total length of the rolling belt;

- contact pressures (stresses) at the pipe-to-tube lattice interfaces after flaring the pipe from the side of the tube bundle entrance (annular space) are much less than at the pipe lattice exit, which increases the probability of the joint density violation from the pipe bundle from accelerated corrosion development namely in this zone.

The invention is aimed at solving the problem of increasing the total length of the rolling milling belt while providing a reliable density of the pipe-tube grating connection, reliability and durability in operation of the milling itself.

The technical result, which is achieved by solving the task, is to increase the productivity of work in the manufacture of heat exchange equipment, in particular when expanding pipes in tube sheets with a thickness of the latter exceeding the optimal working length of the roller.

The specified technical result during the implementation of the invention is achieved by the fact that the rolling includes a cage-separator, conical milling rollers having milling belts and head and tail end sections, windows for their installation, made on the casing-separator uniformly around the perimeter with a central angle of 120 ° between adjacent windows and a rotation of the axis of the latter at a given angle to the generatrix of the housing, the spindle passing along the axis of the housing, wherein, according to the invention, said windows are arranged in longitudinal rows of three windows of different lengths, the extreme windows of the longitudinal rows of the case in each row and the rollers installed in them are also made of different lengths, while the distance between the rolling belts of the rollers in the adjacent windows of each row along the length of the case is the same and equal to the sum of the selected lengths of the body jumpers between the said windows and made equal rounding lengths of the head and tail end sections of each roller adjacent to the corresponding boundaries of the rolling belt, the length of the rolling belt of the first roller in the window of the first the origin of the longitudinal row is less than the length of the rolling belt of the first roller in the window of the second longitudinal row along the perimeter of the casing by the sum of the distance indicated above between the rolling belts of the rollers in the adjacent windows of each row and the selected constant value of the mandatory overlap of the end sections of the rolling belts of the second rollers in the corresponding windows of each row the counter section of the rolling belt of at least one roller in the window of one of the adjacent rows along the perimeter of the housing, the length of the rolling belt and the first roller in the window of the second longitudinal row is less than the length of the rolling belt of the first roller in the window of the third row by the same amount, while the length of the last does not exceed the established allowable value according to the strength conditions, the length of the rolling belt of the third roller in the window of the first longitudinal row is equal to the length of the rolling belt the first roller in the window of the third longitudinal row, the length of the rolling belt of the third roller in the window of the second longitudinal row is equal to the length of the rolling belt of the first roller in the window of the same row, and the rolling belt of the third roller in the window of the third longitudinal row is equal to the length of the rolling belt of the first roller in the window of the first longitudinal row, and the length of the rolling belts of the second rollers in the windows of each longitudinal row is the same, and the total length of the rolling belt of rolling is equal to the sum of the lengths of the rolling belts of all three rollers in the windows of any longitudinal row and the aforementioned doubled distance between the rolling belts of the rollers in the adjacent windows of each row.

Indeed, the housing of the inventive rolling compared to the prototype has greater strength, since the main and additional milling rollers, also made conical, are arranged sequentially in each longitudinal row with gaps between the milling belts of the rollers in the adjacent windows of each row, overlapped by the milling belts of the rollers in the windows of adjacent rows along the perimeter of the body, the end sections of the rolling belts of the second (middle) rollers in the corresponding windows of each row are made with mandatory mutual overlapping by the opposite end portion of the rolling belt of the roller in the window of one of the adjacent rows along the perimeter of the housing, and the length of the mutual overlapping of the end sections of the rolling belts of these rollers is chosen to be the same and should be within a given value.

Running along the generators of the separator case in one row of three windows of different lengths and the indicated placement of the main and additional rolling rollers in them provided, in comparison with the prototype, a larger increase in the total length of the rolling belt, which will allow for a given contact voltage (pressure) between the pipe and with the wall of the hole in the tube sheet, to connect, if not from one rolling unit, then with a smaller number of transitions, which will increase the productivity of work without reducing the operational qualities of the rolling.

The implementation of the extreme rolling rollers in each longitudinal row of the inventive rolling of different lengths provides the specified density of the connection (contact stress) between the pipe and the wall of the hole of the tube sheet on the length of the rolling belt of the end roller of a shorter length along the perimeter of the pipe after the pipe flare as from the side of the tube bundle into the tube sheet (annular space), and from the side of its exit.

The declared mutual dependences of the lengths of the rolling belts of the rolling rollers, taking into account the recommended limitations and sizes of the individual elements of the rollers and the rolling body, allow you to determine the geometric parameters of each roller, its specified elements and choose the optimal value of the total length of the rolling belt of the rolling itself to solve specific technological problems.

The analysis of the prior art by the applicant but to available sources did not reveal information about analogues that are characterized by features that are identical (identical) to all the essential features of the claimed invention. The identification of the closest but the totality of the essential features of the analogue made it possible to identify the totality of the essential features but in relation to the previously indicated technical result from the use of distinctive features in the claimed device set forth in the claims.

Therefore, the claimed invention meets the eligibility condition "novelty."

An additional search carried out by the applicant on available sources of information did not reveal known solutions, the essential features of which would coincide with the distinctive features of the claimed device. This confirms that the claimed invention does not derive for a specialist explicitly from the prior art.

Therefore, the claimed invention meets the eligibility condition "inventive step".

The absence of technical, technological or other obstacles to the industrial implementation of the invention ensures its compliance with the eligibility criterion of "industrial applicability".

The invention is illustrated by the following examples of its specific implementation, which, however, do not exclude other possible options within the scope of the claimed claims, and the drawings, on which:

- figure 1 - the inventive rolling in a longitudinal axial section;

- figure 2 is a section aa in figure 1 (enlarged and rotated), explaining the relative position of the rolling rollers and spindles in the rolling body;

- figure 3 is a diagram of the location of all the rolling rollers of the inventive rolling on a scan of its side surface, taking into account the dependencies indicated in the claims between the sizes of the rolling belts of the rollers and their relative position with the optimal length of the rolling belt of the second rollers in each row but the length of the rolling body;

- figure 4 is the same, with a permissible reduction in the length of the milling belt of the second rollers in each row along the length of the milling body.

The inventive rolling includes a cage-separator 1, along the axis of which a spindle 2 passes with a nut 3 at its front working end and a shank 4 made on the opposite end for connecting to the spindle rotation drive 2. The front working part of the cage-separator 1 is made with windows for installing conical rolling rollers 5, made along the generatrix of the housing 1 evenly around its perimeter with a Central angle of 120 ° between adjacent windows along the perimeter of the housing (see figure 2) with a turn of the axis of the windows and the rollers installed in them under a predetermined angle to said generatrix of the housing in a plane tangent to them. To set the specified rolling interval on the housing 1, a thrust sleeve 6 mounted along the axis of the housing is installed in the rear part thereof, connected through a bearing 7 to a casing 8. The thrust sleeve 6 is tilted on the casing 1 in the desired position by means of a locking screw 9, while the end face of the casing 8 after the separator body 1 is inserted into the roll pipe 10, it usually rests against the tube sheet 11 and determines the location of the common rolling belt of the roll relative to the tube sheet 11 by the thickness of the latter.

One of the features of the inventive rolling is that along the mentioned generators of the cage-separator 1 there are three windows of different lengths arranged in a row and rolling rollers 5 of the corresponding length are placed in them, while, unlike the prototype, all the rolling rollers 5 are conical, the windows of each row of the housing 1 for their installation have a corresponding shape and are located along the generatrix of the housing common to them, which intersects with the middle of the longitudinal axis of each roller 5 and, accordingly, the windows for its installation, and the longitudinal axis l the latter are rotated relative to the mentioned generators around the indicated point of their intersection in the plane tangent to them at a given angle γ (within 0 ° 30 '... 4 °). These and other distinctive features of the structural design of the rolling elements, their relative relative position and the interdependence of the sizes of the parts of the rolling elements indicated in the claims, is more clearly illustrated by figure 3 of the attached drawings, which shows the layout of the rolling rollers 5 of the claimed rolling relative to each other. In view of the designations of the parts of the roller elements of the inventive rolling shown in this figure and the mutual dependence of their sizes indicated in the claims, the following can be written:

if l ₁₁ , l ₂₁ , l ₃₁ - the lengths of the rolling belts of the first (leftmost in FIG. 3 and FIG. 4), second and third rollers of the first row from the origin (top in the drawings),

l ₁₂ , l ₂₂ , l ₃₂ - the lengths of the rolling belts, respectively, of the first, second and third rollers of the second row,

l ₁₃ , l ₂₃ , l ₃₃ - the lengths of the rolling belts of the first, second, and third rollers, respectively, of the third row,

b is the length of the jumper between adjacent windows of the housing in each longitudinal row,

- длина округления хвостового концевого участка каждого ролика,

- the length of the rounding of the tail end portion of each roller,

- длина округления головного концевого участка каждого ролика,

- the rounding length of the head end portion of each roller,

then the gap "B" between the rolling belts of adjacent rollers in the windows of any longitudinal row is determined by the expression

примет видand when

will take the form

where l _c is the length of the fillet end ends of each roller.

From the claims and figure 3 of the drawings it follows that the total length of the rolling belt of the rolling itself L _Σ can be determined by any of the following expressions:

From the claims it also follows that

where C is the value of the mandatory mutual overlap of the end sections of the rolling belts of the second (middle) rollers in the windows of each longitudinal row by the counter end sections of the rolling belts of at least one of the rollers in the windows of one of the adjacent longitudinal rows of the housing along its perimeter, and also:

where l _add - the permissible length of the rolling belt of the first roller of the third row according to the strength conditions;

If now we substitute the value of l ₁₂ from expression (6) into expression (5), we obtain

Dependence (11) is confirmed from consideration of the graphic image of the sizes of the milling belts of the rollers indicated in it in the diagram of FIG. 3. This scheme allows you to write another dependency

Where from

From a consideration of the graphic image of the sizes and relative relative positions of the rollers of the inventive rolling in the diagram of Fig. 3, it is obvious that the length of the second (middle) rollers of each row can be reduced without violating the set of essential features specified in the claims. Their length in this case can be

The layout of all the rolling rollers of the inventive rolling on a scan of its lateral surface, taking into account the reduced length of the second (middle) rollers of each row to the indicated in relation (14), is shown in figure 4 of the attached drawings. The dependence of the size of the remaining rollers and the total length of the rolling milling belt according to the scheme in figure 3 and figure 4 remains unchanged. The difference in rolling according to the scheme in figure 3 is that the gaps "B" between the rolling belts of adjacent rollers of all the rolling rows but the length of its rolling belt L _Σ do not coincide and are shifted relative to each other by at least the specified value "C" of the obligatory overlapping of the end sections of the rolling belts of the second (middle) rollers in the respective windows of each row with the counter end section of the rolling belt of the roller in the window of one of the adjacent rows around the perimeter of the housing. And this means that the contact stresses at the pipe-to-tube lattice interface after tube expansion in equal sections of length equal to the length of the rolling belt of the first roller of the first row (l ₁₁ ) and the third roller of the third row (l ₁₁ ) from the corresponding ends of the tube sheet identical and will have a maximum predetermined value, and between the indicated sections these voltages will periodically decrease slightly at the same length equal to the distance "B" between the rolling belts of adjacent rollers of any row, and again in to turn to the maximum value in adjacent sections with a length equal to the value "C" of the specified mandatory mutual overlap of the end sections of the milling belts of the second (middle) rollers of each row. In the rolling according to the scheme in Fig. 4, this pattern is partially violated: in the middle part along the length of the rolling belt L _{Σ, there} is a combination of the gap "B" between the rolling belts of the rollers 5 of two longitudinal rows (the first and third according to the scheme in Fig. 4), and a decrease in contact stresses at the pipe-tube lattice interface in this section will be more noticeable. However, this fact will practically not affect the overall density of the rolling joints and will not cause a deterioration in the reliability and other indicators of the connection.

Therefore, the inventive rolling, ceteris paribus, can be made with the length of the rolling belt L _Σ in a certain range of values.

If we substitute the value l ₁₁ from expression (11) into expression (2), replacing l ₁₃ in the latter based on expression (7), equal to l ₃₁ equal to

Then, after replacing l _{21 with} its value from expression (13) for rolling according to the scheme in Fig. 3, we obtain:

and after replacing l _{21 with} its value from expression (14) for rolling according to the scheme in Fig. 4, we get:

In other words, ceteris paribus, the rolling in accordance with this invention can be made with a total length of the rolling belt at least in the range from 2l ₃₁ +2 (B + C) to 2l ₃₁ + B + C due to the possible change in the length of the second (medium ) rollers of all longitudinal rows of rolling ranging from l ₂₁ = l ₂₂ = l ₃₁ = 2B + 3C from expression (13) to

l ₂₁ = l ₂₂ = l ₃₁ = B + 2C from expression (14).

However, the total length of the rolling belt of rolling (L _Σ ) can be further increased if the length of the rolling belt of the second (middle) rollers of each longitudinal row is increased to the size of the rolling belt of the third roller of the first longitudinal row or equal to the rolling belt of the first roller of the third row, i.e. .

l ₂₁ = l ₂₂ = l ₃₂ = l ₃₁ .

If in expression (2) l _{21 is} replaced by l ₃₁ , and instead of l ₁₁ substitute its value from (11), we obtain:

и

или "l_c" (при

) и "С" выбирать и конкретное значение общей длины вальцовочного пояса самой вальцовки L_Σ с последующим расчетом остальных параметров элементов вальцовки. Возможен предварительный выбор и длины вальцовочного пояса первого ролика в окне первого продольного ряда в схеме на фиг.3 или фиг.4 или равной ему длины вальцовочного пояса третьего ролика третьего продольного ряда, поскольку она определяет длину входного и выходного участков в соединении труба-трубная решетка с заданной максимальной плотностью соединения после развальцовки труб.This allows when choosing for technical, technological or other reasons, specific values of the values of "b",

and

or "l _c " (at

) and "C" choose a specific value of the total length of the rolling belt of the rolling itself L _Σ with the subsequent calculation of the remaining parameters of the rolling elements. It is possible to preselect the lengths of the rolling belt of the first roller in the window of the first longitudinal row in the diagram of FIG. 3 or FIG. 4 or equal to the length of the rolling belt of the third roller of the third longitudinal row, since it determines the length of the input and output sections in the pipe-tube grating connection with a given maximum joint density after pipe expansion.

The values of the above rolling elements selected for calculation can have an absolute value within the following limits:

- "b" - from 3 to 6 mm - according to the conditions of strength of the material of the rolling mill and the magnitude of the possible loads;

и

- от 2 до 4 мм - из практических данных;-

and

- from 2 to 4 mm - from practical data;

- "C" - from 2 to 4 mm - to ensure guaranteed overlap of the boundary sections of the rolling belts of the respective rollers.

Given that the maximum length of the rolling belt of the third roller in the window of the first longitudinal row, equal to the length of the rolling belt of the first roller in the window of the third longitudinal row, should not exceed 40 mm for pipes with an inner diameter of up to 13 mm, the possible maximum length of the rolling belt of the first roller in the window the first longitudinal row is determined from expression (11). The maximum length of the rolling belt of the first roller of the first longitudinal row depends on the rigidity of the requirements for the density of the inlet and outlet sections of the pipe-tube grating connection, but it is desirable that it be at least 6 mm. In this case, the minimum length of the rolling belt of the third roller in the window of the first longitudinal row is determined from the same expression (11):

For the expansion of pipes with a diameter of 16 mm with a wall thickness of 1.2 mm and 1.4 mm in tube sheets with a thickness of 125 mm, 140 mm and 170 mm, in the manufacture of heat exchangers for various power plants, the applicant has developed one standard size of the inventive rolling NTTsT-270. In this case, the following dimensions were adopted for the above selected rolling elements:

, с=3 ммb = 4 mm

, s = 3 mm

Then from the expression (1) the length of the gap "B" between the rolling belts of adjacent rollers in the windows of any longitudinal row is determined, which will be:

B = b + 2l _c = 4 + 2 × 3 = 10 (mm)

Based on the requirements for the quality (density) of the joints of the inlet and outlet pipe sections in the tube sheets for the manufactured heat exchangers of power plants, the length of the rolling belt of the first roller of the first longitudinal row "l ₁₁ " is taken to be

l ₁₁ = 10.5 (mm),

and the length of the rolling belt of the third roller in the window of the first row is determined from the expression (11) and is

l ₃₁ = l ₁₁ +2 (B + C) = 10.5 + 2 (10 + 3) = 36.5 mm

Since the expansion of pipes in tube sheets of the indicated series of thicknesses can be carried out in only two transitions, to ensure normal operation and durability of the rolling, the optimal total length of its rolling belt is selected from the calculation of the complete overlap of the largest thickness of the tube sheet (170 mm) from the specified row in two transitions with ensuring mutual overlapping of rolled sections with a length of 4 mm, i.e.

L _Σ = (1704 + 4) / 2 = 87 (mm)

Then the length of the second (middle) rollers in the windows of each longitudinal row is determined from expression (2) and will be (after transformations of expression 2):

l ₂₁ = l ₂₂ = l ₂₃ = L _Σ -l ₁₁ -l ₃₁ -2V = 87-10.5-36.5-2 × 10 = 20 (mm),

and the length of the first and third rollers in the windows of the second longitudinal row can be determined by any of the above expressions (3), (5), (6) and will be (from expression 5):

l ₁₂ = l ₃₂ = l ₁₁ + B + C = 10.5 + 10 + 3 = 23.5 (mm)

Now, it is easy to determine the full dimensions of all, without exception, rollers of the inventive rolling and the associated dimensions of the separator body, the full length of which is determined by technological considerations (the number of milling transitions when rolling the same pipes in tube sheets of greater thickness) and the structural dimensions of the assembly of the thrust sleeve ( 6) clip (8).

From the foregoing, it is possible to calculate the minimum and maximum length of the total rolling belt of the inventive rolling.

To calculate the minimum total length of the rolling milling belt, it is necessary to take the minimum of the recommended (or permissible) values of the length of the milling belt of the first roller in the window of the first longitudinal row, in particular:

l ₁₁ = 6 mm

Then the minimum length of the rolling belt of the third roller in the window of the first longitudinal row is determined from the expression (11):

l ₁₁ = l ₁₃ -2 (B + C) or l ₁₈ = l ₁₁ +2 (B + C) = 6 + 2 (10 + 3) = 32 (mm)

The minimum length of the second (middle) rollers in the window of any longitudinal row is determined by expression (14) and is:

l ₂₁ = l ₂₂ = l ₂₃ = B + 2C = 10 + 2 × 3 = 16 (mm).

Then the minimum total length of the rolling belt of the inventive rolling from the expression (2) will be:

The maximum total length of the rolling belt of the claimed rolling is determined from expression (18), if the length of the rolling belts of the second and third rollers in the corresponding windows of the first longitudinal row is taken to be equal to the maximum permissible value of 40 mm for pipes with an inner diameter of 13 mm. She will make:

However, in any of the cases considered, the inventive rolling retains all the essential features indicated in the claims.

The work of the inventive rolling when connecting pipes of a specified size with tube sheets of the aforementioned series of thicknesses in the manufacture of heat exchangers is as follows.

Since when connecting pipes to the tube sheet of heat exchangers manufactured by the applicant, it is necessary to pre-connect the output ends of the tube bundle to the tube sheet by welding to the last pipe ends along their perimeter, pipe expansion in the holes of the tube sheet in this case can be started from the outlet end of the pipes or by slightly departing from it . To do this, when the locking screw 9 is released, the thrust sleeve 6 is moved along the housing 1 to a position in which the working end of the clip 8 is in a predetermined position relative to the boundary of the tail section of the total rolling belt of the rolling, after which the position of the sleeve 6 (and, respectively, the clip 8) is again fixed by the locking screw 9. In this position, the rolling body 1 with the spindle 2 installed along its axis, the front end of the latter with a nut 3 is inserted into the rolling pipe 10 until the end of the sleeve 8 rests in the tube sheet 11 or protrudes out of it hydrochloric end of the tube 10. Then the axial displacement of the spindle 2 carried a radial displacement of rolling rollers 5 before the pipe 10 between, the rollers 5 and reliable coupling shank 2. Then, the spindle 2 is informed of the rotation from the drive associated with the shank 4 of the spindle 2. As the drive, electric or pneumatic motors with a torque limit on its shaft are used to end the flaring. When the spindle 2 rotates due to the rotation of the axes of rotation of the rollers 5 relative to the generators of the separator housing 1 and the spindle axis 2 under the action of friction forces, the spindle 2 is automatically further extended (self-tightening) and the diameter of the rollers 5 is increased - pipe expansion. This increases the torque on the motor shaft. For a given degree of expansion of the pipe 10 in the hole of the tube sheet 11, the torque on the motor shaft reaches the set value and the automatic engine shutdown system is activated. Now the spindle 2 is reported to rotate in the opposite direction and the rolling is removed from the pipe 10. To complete the expansion of the pipe 10 in the hole of the tube sheet 11, the locking screw 9 is released over the entire thickness of the latter and the thrust sleeve 6 with the cage 8 is moved until the working end face is installed at a distance from the border the head portion of the total rolling belt of rolling, equal to the thickness of the tube sheet 11. After that, the position of the thrust sleeve 6 with a clip 8 is again fixed with a locking screw 9, the rolling is introduced into a partially expanded pipe 10 until the end of the end of the cage 8 in the tube sheet 11 and repeat all the operations of the first transition of the expansion. After the flaring of one pipe 10 in the tube sheet 11 is transferred to the flaring of the next pipe. To increase the productivity of work, it is possible to perform the first flare transition in series for all pipes installed in the tube sheet, followed by the sequential execution of the second flare transition.

Tests conducted at the applicant’s tests of manufactured pipe-to-pipe connection units made using the inventive rolling confirmed the quality of the joints made to meet the established requirements while increasing work productivity by more than 30% by reducing technological transitions of pipe expansion in pipe sheets of the same thickness from three to four transitions when using known self-tightening rolling up to two transitions by increasing the total length of the rolling belt ama rolling.

Therefore, the inventive rolling provides a solution to the problem with the achievement of the above technical result and can be recognized as an invention with the provision of legal protection.

Claims (1)

Rolling, comprising a cage-separator, conical milling rollers having milling belts and head and tail end sections, windows for their installation, made on the separator casing uniformly around the perimeter with a central angle of 120 ° between adjacent windows and a rotation of the axis of the latter at a given angle to spindle forming along the axis of the housing, characterized in that the said windows are arranged in longitudinal rows of three windows of different lengths, the extreme windows of the longitudinal rows of the housing in each row and the roles established therein ki are also made of different lengths, while the distance between the rolling belts of the rollers in the adjacent windows of each row along the length of the case is the same and equal to the sum of the selected lengths of the body jumpers between the said windows and the equal rounding lengths of the head and tail end sections of each roller adjacent to the corresponding to the boundaries of the rolling belt, the length of the rolling belt of the first roller in the window of the first from the origin of the longitudinal row is less than the length of the rolling belt of the first roller in the window the circumferential length of the longitudinal row for the sum of the above-mentioned distance between the rolling belts of the rollers in adjacent windows of each row and the selected constant value of the mandatory overlap of the end sections of the rolling belts of the second rollers in the corresponding windows of each row with the counter section of the rolling belt of at least one roller in the window of one of the adjacent rows along the perimeter of the housing, the length of the rolling belt of the first roller in the window of the second longitudinal row is less than the length of the rolling belt of the first the length of the third roller in the window of the first longitudinal row is equal to the length of the rolling belt of the first roller in the window of the third longitudinal row, the length of the rolling belt of the third roller in the window of the second longitudinal row is equal to the length of the rolling belt of the first roller in the window of the same row, the length of the rolling belt of the third roller in the window of the third longitudinal row is equal to the length of the rollers full-length belt of the first roller in the window of the first longitudinal row, and the length of the rolling belts of the second rollers in the windows of each longitudinal row is the same, and the total length of the rolling belt of rolling is equal to the sum of the lengths of the rolling belts of all three rollers in the windows of any longitudinal row and the aforementioned double distance between the rolling belts rollers in adjacent windows of each row.

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