JP3454480B2 - Permanent bending method for deformable body - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is directed to precise plastic or permanent deformation which does not depend on 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 plastic deformation direction 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 accomplished 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 the bending of multiple bodies with the same structural and operational properties, based on the molecular and physical structure of the bodies to be bent and the nominal values of the dimensions, Calculated to ensure a constant plastic deformation of the body.

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 sequential bending operation for each body to be bent until the desired 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 imparted 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 unfixed 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 impossible to achieve a plastic deformation with a uniform degree of 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. It 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, which method is independent of the body and which has 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 a formula for the "angular displacement x plastic deformation" standard curve for the type of body to be bent, b) bending the other longitudinal part of each body Fixing from the working line to a 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 the position before the angular displacement is given; f) obtained in step e Based on the degree of plastic deformation, a new formula of “angular displacement × 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 portion of the body, and g) corresponding to the angle determined in step f around the bending line, in the non-fixed portion 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 removing the body exhibiting the desired plastic deformation from the fixing device.

The operating sequence includes only one second plastic deformation angular displacement in order to achieve the bending of the body within the tolerances 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 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 which the bending is applied. ) Is possible, and even in that case, high precision 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 effective for particularly accurate and automatic bending (industrial product standard) of a metal blade used for manufacturing a reed valve for a hermetic compressor. In 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) A method for accurate plastic deformation of a metal blade which 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 comprises bending one end of a metal blade or rod 10 about a bending line transverse to the longitudinal axis of the blade 10. Used to achieve exact plastic deformation. In this example, said patent application number BR 900
As described in 2967, the blade 10 refers to 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 that are homomorphic with respect to outer dimensions, molecular structure and microstructure, it is empirically necessary to establish a relationship between different angles of angular displacement.
The angular displacement is applied around the bending line in the plastic deformation that has occurred 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 the 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 enables 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 the initial distance D0 between the blade that is not bent and the reference points that are spaced in the direction in which the bending is applied, 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 determining 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, i.e. in a plane orthogonal 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 step 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. Bending the non-fixed portion 12 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 multiple blades. In order to make the 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 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 step 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 part 12 of the blade 10, the cylindrical rod 40 is retracted by 41 and 42 constituting the table motor, so that the non-fixed part 12 is moved. 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 particular application together with a corresponding correction of a particular curve. The second plastic deformation position P2, which is in the value, is inactivated 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 and 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 measurement 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 sends a signal to the central processing unit, revealing the presence of the pieces around it and then the permanent sensing which 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 located 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, after each bending propulsion means, the already bent pieces are automatically processed by the central processing unit.

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. It is related to the movement of a micrometer table equipped with both. In the contrary situation, if the micrometer table comprises lamina that are 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 first angular displacement of two stages 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 Opposite directions-several additional displacements are in the same direction as the primary displacement, other additional displacements are in the opposite direction to the primary displacement and 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 deformation value.
To be within the range. In this case, like all other cases with 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 a permanent bending process.

[Explanation of symbols] 10 blade 11 Fixed part 12 Non-fixed part 20 Fixing device 21 pads 30 Sensing device 31 Stylus 40 cylindrical rod 41 micrometer table 42 step motor 50 Central processing unit 51 digital interface 52 Measuring element signal conditioner 60 analog interface

Continuation of front page (56) Reference JP 61-129522 (JP, A) JP 61-232018 (JP, A) JP 61-63317 (JP, A) JP 61-229421 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 5/00-9/18

Claims (13)

(57) [Claims] Claim: What is claimed is: 1. An elongated body for defining two parts which are connected to each other via a bending line which is at least substantially transverse to the longitudinal axis of the body and which are dihedral. A method of permanent bending of a deformable body, a) various angular displacements applied around a bending line with respect to one longitudinal portion of each body of the same type, resulting By empirically setting the relationship between plastic deformation and the "angular displacement
Determining the expression of plastic deformation "standard curve and the other longitudinal portion of b) each body, and the step of fixing the fixing device from the bending line, c) with respect to a reference fixed point, in the non-fixed portion of the body Measuring the initial position of at least one point and recording the initial value of this relative position; d) taking into account the formula defined in step a, for the non-fixed part of the body to be bent. Desired plastic angle
Desirably around the bending line at an angle corresponding to the realization of a deformation value that is between 60% and 90% and between 110% and 120% of the desired plastic angular deformation, which is intentionally different from the deformation A first angular displacement in the direction of plastic deformation of the body; and e) non-fixation of the body to define the degree of plastic deformation obtained by the angular displacement applied to the non-fixed portion of the body. Measuring the new angular position of said point in the part and comparing the angular position with the position before giving the displacement, f) the plastic deformation obtained in step e in order to achieve the desired plastic deformation. Based on the degree of As a specific curve formula Defining step; and g) applying another angular displacement around the bending line at an angle corresponding to the angle defined in step f with respect to the non-fixed part of the body to be bent. H) Steps e, f and g are performed on the body to be bent in order to realize the finally desired plastic deformation.
Applying the sequence consisting of at least once, and i) removing the body exhibiting the finally desired plastic deformation from the fixing device.
The method. 2. The method according to claim 1, wherein the at least one additional angular displacement is in the direction of the finally desired plastic deformation, the displacement causing a plastic deformation closer to the finally desired plastic deformation. 3. The method of claim 2, wherein a plurality of additional angular displacements in the direction of the finally desired plastic deformation are provided, the displacements causing each of the plastic deformations to become progressively closer to the finally desired plastic deformation. The method described. 4. The method according to claim 3, wherein the additional angular displacement is performed continuously. 5. The method of claim 4, wherein the additional angular displacements are all in the same direction. 6. The method according to claim 5, wherein the additional angular displacements are all in the same direction as the finally obtained direction of plastic deformation. 7. The method of claim 6, wherein at least the last additional angular displacement occurs in the opposite direction to the previous displacement. 8. The method according to claim 7, wherein at least the last additional angular displacement occurs in the opposite direction to the first angular displacement. 9. The method according to claim 1, wherein the at least one angular displacement in the direction of the last plastic deformation corresponds to the resulting at least one corrected angular displacement in the opposite direction. 10. The method according to claim 1, wherein at least one angular displacement occurs in a direction opposite to the direction of the finally desired plastic deformation. 11. A new angular position of a point in the non-fixed portion of the elongated body is measured prior to releasing the body to define the pass / fail of the part and the point at which the desired plastic deformation state should be exhibited. The method of claim 1, further comprising the step of comparing 12. A method of bending a first part of a body to a second part up to a required plastic deformation, the method comprising: (i) calculating from a relationship between displacement and deformation empirically determined in advance. Intentionally different from the required plastic deformation
Between 60% and 90% of the required plastic deformation, or 11
Corresponding to the expected plastic deformation between 0% and 120% ,
Determining a first angular displacement to be applied, (ii) applying the first angular displacement to the first portion, (iii) measuring the obtained plastic deformation, (iv) From the measured plastic deformation, a new relationship between subsequent angular displacement and plastic deformation is determined, and a second angular displacement to be applied is determined to approach or achieve the required plastic deformation. And (v) applying the second angular displacement to the first portion of the body. 13. A method of bending a metal blade according to claim 12, wherein the blade is of a type adapted to be used in a reed valve of a hermetic compressor. A method of bending a blade.