JPH05212448A - Method for permanent bending of deformable body - Google Patents

Abstract

PURPOSE: To provide a method for bending to attain exact plastic deformation and permament deformation in spite of variations which may be caused in microstructure, molecular structure, and outside dimension. CONSTITUTION: Initial angular displacement of a nonfixed part of a blade 10 positioned on a fixing device is made by a cylindrical rod 40 driven by a step motor 42, the deformation is detected by a sensing device 30 equipped with a probe 31, and the information is sent to a central processing unit 50. The central processing unit 50 gives corresponding commands to a step motor 42 so as to establish a new 'annular displacement × plastic deformation' standard curve, to define a second additive angular displacement given to a nonfixed part of the blade 10 as a mathematical and new prescribed function curve, and to cause a deformation of a cylindrical rod through a micrometer table 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is directed to precise plastic or permanent deformation independent of dimensional deviations from predetermined nominal values for a given microstructure or molecular structure and / or different bodies. To achieve
Generally, it relates to an automatic bending method for different bodies such as metal rods and blades.

[0002]

BACKGROUND OF THE INVENTION Automatic bending of bodies, generally in the form of elongated rods and blades, involves only the angular displacement in the desired direction of plastic deformation of the body to which one end of the longitudinal extension is normally fixed. Achieved through the operation of applying a one-time bending operation to the non-fixed end, said displacement being
It was achieved in a single plastic deformation operation that exerted a force on the non-fixed part of the body to be bent. The displacement takes into account the values obtained from bending of multiple bodies having the same structural and operational properties, and is based on the molecular and physical structure and nominal values of the body of the body to which the bending is applied. Calculated to ensure a constant plastic deformation of the body.

[0003] In some technology applications, conventional automatic bending methods that provide a single angular displacement in a fixed direction to the unfixed portion of the body include applying the desired technology to the body being bent. Is sufficient to cause deformation within the body within strict criteria that requires

[0004]

However, in the case where it is basically necessary to achieve bending or plastic deformation within a very strict limit, these conventional automatic bending methods have a plurality of techniques of the same type. During plastic deformation of each body,
The tolerances that normally occur due to the dimensions of the body and the microstructure and molecular structure are not considered as relative parameters. This problem can be solved by a cumulative bending sequential operation on each body to be bent until the desired and accurate result is finally obtained. However, in industrial products, for example, in the manufacture of reed valves for hermetic compressors used in small refrigeration systems, the sequential deformation steps applied to each reed valve, the reed valve accuracy due to the actual manual operation of the reed valve It is impossible to achieve perfect bending.

[0005]

SUMMARY OF THE INVENTION In the currently known automatic bending methods, the angular displacement applied to the non-fixed portion of the body that is bent to ultimately achieve the desired plastic deformation is: It is calculated taking into account only one body with nominal properties for multiple bodies to be bent. Except for a special case, the body selected from the plurality of bodies to be bent actually has a predetermined outer dimension and a microstructural variation value relative to each other. Therefore, at the time determined by the reed valve of the hermetic compressor described above, the automatic operation is performed for all the bodies selected from the plurality of bodies without deviating from the strict and accurate limits set for the bodies. It is not possible to achieve a plastic deformation of uniform homogeneity.

Therefore, it is an object of the present invention, in spite of the possible variations in microstructure, molecular structure and external dimensions with respect to the desired nominal value of the deformable body, in the plastic deformation of the body by rapid automatic operation. The object is to provide an automatic and permanent bending method that guarantees a strict degree.

A further object of the present invention is to provide an automatic bending method as described above, the method being independent of the body and having a predetermined value relating to each body, which can take various values. It is also possible to determine the angle of plastic angular deformation of the body as a function of the dimension parameter, so that the plastic deformation of a given body is achieved as a function of the dimension parameter independent of said body. The method is suitable under this circumstance when the piece to be bent is assembled by other bodies or by various dimensional parts of the piece, whereby
The process of selecting and grouping pairs of dimensionally compatible pieces can be avoided.

According to the invention, for determining two parts of a dihedral angle which are joined together in said body by a bending line which is at least substantially transverse to the longitudinal axis of the body. An automatic bending method for a plastically deformable, elongated body, comprising: a) different angles applied around the bending line with respect to a portion of the longitudinal portion of the same type of body that undergoes plastic deformation. Empirically setting the displacement relationship between the two, and defining the formula for the "angular displacement x plastic deformation" standard curve for the type of body being bent, b) bending the other longitudinal part of each body Fixing from the working line to the fixing device, c) measuring at least one of the basic positions of the non-fixed part of the body relative to the reference fixing point and recording the initial value of this relative position, d Step a, around the bending line and in the direction of the desired plastic deformation, at an angle corresponding to achieving a deformation value between 60% and 90% and 110% and 120% per interval. Giving a first angular displacement to the non-fixed part of the body to be bent, taking into account the defined formula, and e) the plasticity obtained by said angular displacement given to the non-fixed part of the body. Measuring a point at a new angle of the non-fixed part of the body to determine the degree of deformation and comparing the point with a position before the angular displacement is given; f) obtained in step e Based on the degree of plastic deformation, a new formula for the "angular displacement x plastic deformation" curve, which is specific to the body for each bending phase, is set, and mathematical and new formulas are established to achieve the desired plastic deformation. As a specific curve formula Determining the additional angular displacement applied to the non-fixed part of the body, g) corresponding to the angle determined in step f around the bending line, in the non-fixed part of the body to be bent. Applying a new angular displacement, h) applying at least one sequence of steps e, f and g to the body to be bent in order to finally achieve the desired plastic deformation, i) finally disengaging the body exhibiting the desired plastic deformation from the securing device.

The operating sequence includes only one second plastic deformation angular displacement in order to achieve the bending of the body within the tolerance required for the application under consideration. However, as defined above, steps e, f, and g are performed until the desired precise plastic angular deformation of the body being bent is achieved.
It may be repeated sequentially.

The bending method further comprises automatically determining the degree of plastic deformation imparted to the body as a function of external dimension parameters which take various values of other factors with which the body must be operatively matched. Is possible.

Another possibility of the present invention is the use of the partial reverse bending method technique (after the initial bending, to obtain a residual tension relaxation effect, if necessary, in the body to be bent. ) Is possible, and even in that case, highly accurate bending can be finally achieved.

[0012]

The bending method of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of an apparatus for carrying out the permanent bending process of the present invention.

FIG. 2 shows the nominal reference curve of "angular displacement * plastic deformation" of the longitudinal part in a plurality of bodies in the form of metal blades. This metal blade is used for manufacturing a reed valve for a small hermetic compressor, and a reference fixing point which is a basic position of a body is spaced from a basic position in a deformation direction.

FIG. 3 is a schematic front view of an apparatus for performing permanent bending.

As described above, the object of the present invention is particularly effective for the accurate and automatic bending (industrial product standard) of a metal blade used for manufacturing a reed valve for a hermetic compressor. As a more specific application, the method is an invention of the same applicant as the applicant of the present invention. British Patent Application No. BR 9002967
(Corresponding to US Serial No. 715,818 / 91) An accurate plastic deformation method for a metal blade that functions as a blade propulsion means for an intake valve and a discharge valve described in US Pat.

According to the accompanying drawings, the method of the present invention involves bending one end of a metal blade or rod 10 about a bending line transverse to the longitudinal axis of the blade 10. It is used to achieve precise plastic deformation. In this example, said patent application no. BR 900
As described in 2967, the blade 10 means a small rod used as an elastic propulsion means for a reed valve of a small hermetic compressor. To begin the process of a predetermined plastic deformation of a plurality of blades 10 which are homomorphic with respect to outer dimensions, molecular structure and microstructure, it is empirically necessary to establish the relationship between the different angles of angular displacement.
The angular displacement is applied around the bending line in the plastic deformation that occurs in part of the longitudinal portion of the blade 10 and in the aforementioned part.

This setting can be done by any suitable method that allows the determination of a sampling of the "angular displacement x plastic deformation" relationship of a plurality of blades 10 of the same type to be bent.

This experimental process allows the determination of the equation of the "angular displacement × plastic deformation" standard curve depending on the type of blade 10 to be bent. An example of this type of curve is shown in Figure 2.
Is shown in. In the figure, the abscissa axis represents the plastic or permanent deformation obtained from the piece, and the ordinate axis represents the angular displacement imparted to the piece to achieve this deformation. This curve shows the desired nominal plastic or permanent deformation expected from the type of blade or piece being bent.

It will be appreciated that the curve or plastic deformation begins after a certain initial displacement of the ordinate axis. This axial displacement is determined by the initial distance D0 between the blade that is not bent and the reference points that are spaced in the direction in which bending is performed, and the initial elastic deformation amount EDe of the piece that is bent. caused by.

After the step of determining the "angular displacement × plastic deformation" standard curve of the type of piece to be bent, effective bending of the plurality of blades 10 is possible.

For this purpose, each of the blades 10 to be bent has a longitudinal extension.
The extension portions are located on both sides of the lateral bending line and attached to the fixing device 20. The fixing device 20 consists of two blocks or pads 21 made of hard alloy in FIG. One of the pads 21, relative to the other pad, whether automatic or not, can be moved and compressed by any suitable means. The two blocks 21 of the fixing device 20 must be made to allow an accurate and complete fixing of the fixing part 11 of the blade 10 held on the fixing device 20. The fixed part 11 usually coincides with the shortest part in the longitudinal direction with respect to the bending line of the piece.

The positioning of each blade 10 on the fixing device 20 should preferably be done by an automatic device which can ensure equal positioning of the blades 10 with respect to the fixing device 20 when the blades are fed to the fixing device 20. It is understood that there is.

After each blade 10 is fixed,
It is necessary to record the original position of the non-fixed portion 12 to be bent in order to receive as a parameter the final angular displacement given to the ten non-fixed portion 12.

One way of recording the basic position of the blade 10 is to provide a plane parallel to the bending direction of the blade between the reference point fixed with respect to the fixing device 20 and the point of the non-fixed part 12 of the blade. There is a way to measure the distance along.

1 to 3, the sensing device 30 is shown schematically. The sensing device 30 is fixed to the fixing device 20 and includes a tracing stylus 31 that is movable from a retracted position corresponding to the reference point until it touches a point on the non-fixed portion 12 of the blade 10. The probe 31 is a blade
It moves according to the bending direction of 10, that is, in the orthogonal plane to the non-fixed part 12. When the probe 31 contacts the blade 10, it is possible for the sensing device 30 to detect new information corresponding to the distance D0 between the reference fixed point and the basic position of the non-fixed part of the blade.

After these initial stages, the non-fixed portion 12 of the blade 10 may be subjected to an angular displacement about the bending line, which laterally or nearly laterally causes the blade's fixed portion 11 and At the connecting portion of the non-fixed portion 12,
It may be determined by the fixing device 20 itself.
The angular displacement of the non-fixed part 12 can be obtained in the bending direction to be achieved, for example by a cylindrical rod 40. This cylindrical rod 40 is arranged parallel to the bending line, and is driven by a step motor 42 (for example, winding 0.5 step).
Effectively linked (for example, 0.5 steps of winding).

The initial angular displacement of the non-fixed portion 12 of the blade 10 is made by moving the step motor 42 so that the cylindrical rod 40 is about the bending line and in a direction such that plastic deformation is obtained. The non-fixed part 12 is bent at an angle α corresponding to 60% to 90% of the desired value of the plastic angular deformation, taking into account the standard formula shown in FIG. 2 for a plurality of blades. In order to obtain a plastic angular deformation smaller than the angle α due to the plastic deformation of the non-fixed portion 12, the angle α shown in FIG. 3 should correspond to the angular displacement given to the non-fixed portion 12. To be observed. Said deformation has already been taken into account in the setting of the "angular displacement x plastic deformation" standard curve of a piece to be subjected to multiple bendings.

An operation command to the step motor 42 can be accessed by an operator, and a digital interface 51 incorporating a special control unit for the step motor 42 is provided.
Commanded to the stepper motor 42 via, for example, a central processing unit 50 represented as a microcomputer in FIG.

Thus, when the angle α reaches the initial angular displacement of the non-fixed portion 12 of the blade 10, the cylindrical rod 40 is retracted by 41 and 42 constituting the table motor, so that the non-fixed portion 12 is It is possible to return to the first position P1 of each plastic deformation shown in FIG.

The central processing unit 50 then commands the stylus 31 of the sensing device 30 to move until the stylus 31 again contacts the non-fixed portion 12 of the blade 10 and, as a result, the sensing device 31.
The 30 can send the obtained information of the first plastic deformation amount D1 to the central processing unit 50 via the gauge head signal adjuster 52 and the digital interface 51. Central processing unit 50
Establishes a new standard curve for the piece to be bent and uses the blade 10 as a mathematical and new normal function curve.
The second additional angular displacement β given to the non-fixed portion 12 of is defined. The second additional angular displacement β is applied to the non-fixed portion 12 of the blade 10.
In order to cause a deformation of the cylindrical rod 40 via the micrometer table 41, a corresponding command is given to the step motor 42, the cylindrical rod 40 being required for a specific application with a corresponding correction of a specific curve. The second plastic deformation position P2, which is in the value, becomes the inactive state so that the non-fixed portion 12 is assumed to be the first bending approach function.

After this, the blade 10 may be removed from the fixture 20.

The initial distance D0 between the reference point and the base position of the blade 10 is determined by the sensing device 30 to be subtracted from the distance D1 measured after the first plastic angular deformation of the blade 10. Similarly, it can be seen that it is registered in the central processing unit 50.

As shown in FIG. 1, the central processing unit 50 has another sensing device through the analog interface 60.
Can be effectively connected to 70. The sensing device 70 is
For example, as a variation value of at least a linear function in the piece or element coupled with each specific blade, in order to determine the value of the plastic deformation given to the blade 10, for each blade subjected to bending It is installed to measure the depth of a specific seat.

In another possible embodiment, the information received from the opposite faces of both laminae is used to determine which portion of the blade will be bent. The measured values obtained from the opposite faces of the two lamellae can be obtained directly by the two sensing devices and, in the case of optical sensing devices, indirectly by reflection.

The automatic activation of the fixing device for fixing the deformed lamina signals the central processing unit to reveal the presence of the pieces around it and then to the permanent sensing that begins the bending process. Done by the device. In a possible embodiment, the central processing unit initiates the bending process,
An instruction is sent back to the fixing device to fix the longitudinal portions of both lamellas opposite the non-fixed portion of the body. Another embodiment comprises a fixing device next to the fixing device which automatically fixes the lamina when its presence is sensed. In both embodiments, the already bent pieces are automatically processed by the central processing unit upon completion of each bending means.

Activation of the deformer on the lamina is provided in the process of bending, which moves equally on the lamina on the lamina, both forward and backward, of the deformer and the sensing device. It is related to the movement of a micrometer table equipped with both. In the contrary situation, if the micrometer table comprises lamina to be bent, the body moves forward or backward in relation to the movement of the position sensing device and the deformation device.

Although only one embodiment of the present invention is described here, in that embodiment, an angular displacement by plastic deformation in the same direction as the initial angular displacement of two steps is performed at one time,
This bending process is, in addition to the primary deformation, -all additional displacements in the same direction and in the same direction as the primary displacement, -all additional displacements in the same direction, and the primary displacement In opposite directions, some additional displacements in the same direction as the primary displacement, other additional displacements in the opposite direction to the primary displacement, the last displacement can be either multiple additional displacements Is understood to include.

It is also possible to carry out the process here with two angular displacements of opposite direction, in which case the first angular displacement is finally 110% to 120% of the desired angular displacement value.
To be within the range. In this case, like all other cases where there is at least one additional angular displacement, in the opposite direction to the forward displacement, which may be a primary displacement or additional displacement, an angular displacement in the opposite direction. Is
It allows the residual tension of the previous displacement to be released.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus for performing a permanent bending method.

FIG. 2 shows a nominal reference curve of “angular displacement × plastic deformation” of a longitudinal section of a plurality of bodies in the form of a metal blade. This metal blade is used for manufacturing a reed valve for a small hermetic compressor, and a reference fixing point which is a basic position of a body is spaced from a basic position in a deformation direction.

FIG. 3 is a schematic front view of an apparatus for performing permanent bending.

[Explanation of symbols]

 10 Blade 11 Fixed part 12 Non-fixed part 20 Fixing device 21 Pad 30 Sensing device 31 Measuring element 40 Cylindrical rod 41 Micrometer table 42 Step motor 50 Central processing unit 51 Digital interface 52 Measuring element signal conditioner 60 Analog interface

Claims (11)

[Claims] 1. For determining in the elongated body two parts which are joined to one another via a bending line which is at least substantially transverse to the longitudinal axis of the body and which are dihedral. , A method of bending a deformable body, a) experience the relationship of different angular displacements applied around the bending line to a portion of the longitudinal portion of the same type of body that undergoes plastic deformation To define the formula of the standard curve of "angular displacement x plastic deformation" for the type of body to be bent, and b) the other longitudinal part of each body from the bending line to the fixing device. Fixing, c) measuring at least one of the basic positions of the non-fixed part of the body relative to the reference fixing point and recording the initial value of this relative position, d) around the bending line and Consider the formula defined in step a, in the direction of favorable plastic deformation, with angles corresponding to the achievement of deformation values between 60% and 90% and 110% and 120% per interval. And applying a first angular displacement to the non-fixed part of the body to be bent, and e) determining the degree of plastic deformation obtained by the angular displacement given to the non-fixed part of the body. In order to measure a point at a new angle of the non-fixed portion of the body and compare the point with the position before giving the angular displacement, and f) the degree of plastic deformation obtained in step e. Based on this, set a new formula of "angular displacement x plastic deformation" curve that is specific to the body for each bending phase, and as a mathematical and new specific curve formula to achieve the desired plastic deformation. Given to the non-fixed part of the body Determining the additional angular displacement, and g) applying a new angular displacement corresponding to the angle determined in step f around the bending line to the non-fixed portion of the body to be bent. , H) applying at least one sequence of steps e, f and g to the body to be bent to achieve the final desired plastic deformation, and i) the final desired plastic deformation. And a step of removing the body exhibiting from the fixing device from the fixing device. 2. At least one additional angular displacement is in the direction of the finally desired plastic deformation, said displacement being closest to the finally desired plastic deformation and causing each plastic deformation associated with the preceding plastic deformation. The method of claim 1. 3. The method of claim 2, wherein a plurality of additional angular displacements are in the direction of the finally desired plastic deformation, the displacements causing each of the plastic deformations to be cumulatively closest to the finally desired plastic deformation. .. 4. The method of claim 3, wherein the additional angular displacements occur sequentially. 5. The method of claim 4, wherein the additional angular displacements are all in the same direction. 6. The method of claim 5, wherein the additional angular displacements are all in the same direction as the finally desired direction of plastic deformation. 7. The method according to claim 6, wherein at least the last additional angular displacement occurs in the opposite direction to the previous displacement. 8. The method of claim 7, wherein at least the final additional angular displacement occurs in the opposite direction to the first stage displacement. 9. The method of claim 1, wherein the at least one additional angular displacement is in the direction of the last plastic deformation and, as a result, corresponds to the at least one corrected angular displacement in the opposite direction. 10. The method of claim 1, wherein the at least one additional angular displacement occurs in a direction opposite to the finally desired direction of plastic deformation. 11. A new position angle of a non-fixed portion point of an elongated body is measured before the body is removed, and that point and the point at which the desired plastic deformation state should be present are used to determine the acceptability of the piece. The method of claim 1, further comprising the step of comparing to.