JP5380906B2 - Caulking device and caulking method - Google Patents

Description

  The present invention relates to a caulking device, and more particularly to a caulking device capable of caulking a caulking member in an appropriate state.

  Conventionally, caulking has been used in production sites for mounting and fixing parts and members. In the conventional caulking device, the caulking member is caulked with a constant load (pressure value) and a constant crushing stroke. However, in such a method, when the mechanical characteristics of the caulking member material and the component dimensions vary greatly, the degree of crushing of the caulking member changes due to the variation, and the caulking member is disengaged due to insufficient caulking. Or the caulking member is damaged due to excessive caulking, and a problem that a desired caulking state cannot be obtained has occurred.

  In particular, in the mounting of a shape memory alloy (hereinafter referred to as SMA), which has been attracting attention as a new actuator in recent years, it is necessary to caulk SMA while applying a constant tension to the SMA. It is important to establish a caulking method that does not cause disconnection due to operating durability.

  Therefore, in Patent Document 1, for example, in an automatic pressure control device of a press device, a pressure sensor is provided in a part of the drive link mechanism to control to automatically adjust the pressure applied to the caulking member, and an origin position sensor is additionally provided. And the method of adjusting a pressurization state automatically by regulating the position of a pressure sensor is proposed.

  Further, for example, Patent Document 2 proposes a method of controlling the driving means so that the clamp height of the crimped terminal is monitored and the detected height becomes equal to a predetermined value in the control method of the terminal crimping apparatus. Yes.

Further, for example, in Patent Document 3, in a press-fitting caulking device, a change point of a load curve composed of a movement amount and a pressing force of a pressing portion at the time of caulking is obtained, and the quality of caulking is determined by comparing with a change point of a reference load curve. A determination method has been proposed.
JP-A-5-159847 Japanese Patent Laid-Open No. 10-3777 JP 2005-131777 A

  However, in the methods of Patent Documents 1 and 2, even if automatic, the load applied to the caulking member and the deformation amount of the caulking member are controlled so as to be equal to a predetermined value. It does not deal with caulking defects due to variations in material mechanical properties and component dimensions.

  Even if the method of Patent Document 3 can determine whether or not the caulking is good, it does not contribute to the reduction of caulking defects.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a caulking device that can reduce caulking defects due to variations in mechanical properties and component dimensions of the caulking members.

  The object of the present invention can be achieved by the following constitution.

1. A pressing portion that applies a pressing force to the caulking member by movement, deforms the caulking member, and fixes the caulking member;
Driving means for moving the pressing portion;
In the caulking device including the pressing unit and a control unit that controls the operation of the driving unit,
A movement amount detecting means for detecting a movement amount of the pressing portion;
The controller is
In the process of applying the pressing force by the pressing unit, an inflection point detection unit that detects an inflection point at which the deformation form of the caulking member changes;
A parameter storage unit that stores in advance a difference between the amount of movement of the pressing unit at the inflection point and the amount of movement of the pressing unit in an appropriate crimped state as a predetermined deformation amount;
A parameter reading unit for reading the predetermined deformation amount stored in the parameter storage unit;
A moving amount for moving the pressing portion to an appropriate caulking position by comparing the moving amount of the pressing portion detected by the moving amount detecting means with the predetermined deformation amount read by the parameter reading portion. have a control unit,
The caulking member is
A bar having a constricted portion and a head having a cross section perpendicular to the pressing direction and having a cross-sectional area larger than that of the constricted portion, and having a deformed portion that deforms first in the caulking process, The deforming portion to be deformed is the constricted portion, and the caulking member is sandwiched by deformation of the deforming portion to hold and fix the caulking member,
The caulking member is
A caulking device characterized by being a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less .

2. A pressing portion that applies a pressing force to the caulking member by movement, deforms the caulking member, and fixes the caulking member;
Driving means for moving the pressing portion;
In the caulking device including the pressing unit and a control unit that controls the operation of the driving unit,
A pressing force detecting means for detecting the pressing force;
The controller is
In the process of applying the pressing force by the pressing unit, an inflection point detection unit that detects an inflection point at which the deformation form of the caulking member changes;
A parameter storage unit that stores in advance a difference between the pressing force at the inflection point and the pressing force in an appropriate caulking state as a change amount of a predetermined pressing force;
A parameter reading unit for reading a change amount of the predetermined pressing force stored in the parameter storage unit;
A pressing force that pressurizes the pressing portion to an appropriate caulking state by comparing the pressing force detected by the pressing force detecting means with a change amount of the predetermined pressing force read by the parameter reading portion. have a control unit,
The caulking member is
A bar having a constricted portion and a head having a cross section perpendicular to the pressing direction and having a cross-sectional area larger than that of the constricted portion, and having a deformed portion that deforms first in the caulking process, The deforming portion to be deformed is the constricted portion, and the caulking member is sandwiched by deformation of the deforming portion to hold and fix the caulking member,
The caulking member is
A caulking device characterized by being a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less .

  3. 2. The caulking device according to 1 above, wherein the inflection point is a point at which a change rate of a movement amount of the pressing portion with respect to a change in the pressing force is equal to or less than a predetermined value.

  4). 3. The caulking device according to 2 above, wherein the inflection point is a point at which a rate of change of the pressing force with respect to a change in the amount of movement of the pressing portion becomes a predetermined value or more.

5. A caulking method for applying a pressing force to a caulking member and deforming the caulking member to fix the caulking member,
The caulking member is
A bar having a constricted portion and a head having a cross-sectional area larger than the cross-sectional area of the constricted portion in a cross section perpendicular to the pressing direction;
The caulking member is
It is a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less,
An arranging step for arranging the shape memory alloy of the wire to contact the constricted portion;
A pressing step of deforming the constricted portion by moving a pressing portion that applies the pressing force to the caulking member;
An inflection point detecting step of detecting an inflection point at which the deformation form of the caulking member changes in the process of applying the pressing force;
A parameter storage step for storing in advance a difference between the amount of movement of the pressing portion at the inflection point and the amount of movement of the pressing portion in an appropriate crimped state as a predetermined deformation amount;
A parameter reading step of reading the stored predetermined deformation amount;
A movement amount detection step of detecting a movement amount of the pressing portion;
A movement amount control step of comparing the detected movement amount of the pressing portion with the predetermined deformation amount read by the parameter reading step, and moving the pressing portion to an appropriate caulking position;
A caulking method characterized by comprising:

6). A caulking method for applying a pressing force to a caulking member and deforming the caulking member to fix the caulking member,
The caulking member is
A bar having a constricted portion and a head having a cross-sectional area larger than the cross-sectional area of the constricted portion in a cross section perpendicular to the pressing direction;
The caulking member is
It is a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less,
An arranging step for arranging the shape memory alloy of the wire to contact the constricted portion;
A pressing step of deforming the constricted portion by moving a pressing portion that applies the pressing force to the caulking member;
An inflection point detecting step of detecting an inflection point at which the deformation form of the caulking member changes in the process of applying the pressing force;
A parameter storage step for storing in advance a difference between the amount of movement of the pressing portion at the inflection point and the amount of movement of the pressing portion in an appropriate crimped state as a predetermined deformation amount;
A parameter reading step of reading the stored predetermined deformation amount;
A pressing force detecting step for detecting the pressing force;
A pressing force control step of comparing the detected pressing force with the change amount of the predetermined pressing force read by the parameter reading step and pressurizing the pressing portion to an appropriate caulking state;
A caulking method characterized by comprising:

  According to the present invention, the point at which the deformation form of the caulking member changes during caulking is detected as an inflection point, and further caulking from the inflection point stored in advance to an appropriate caulking state. The pressing portion is moved or pressurized by the amount of change of the pressing portion or the pressing force. As a result, it is possible to provide a caulking device that can reduce caulking defects due to variations in the mechanical characteristics and component dimensions of the caulking member material.

  Hereinafter, the present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant description is omitted.

  First, a caulking apparatus according to the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing an outline of the caulking apparatus according to the present invention.

  In FIG. 1, a caulking device 1 includes a control unit 11, a servo motor 13, a coupling 15, a ball screw 17, a pressing unit 19, a table 31, and the like. The pressing unit 19 includes a caulking punch 21, a pressure sensor 23, a moving shaft 25, and the like. Here, the servo motor 13, the coupling 15, and the ball screw 17 function as drive means in the present invention.

  The servo motor 13 is coupled to the ball screw 17 via the coupling 15, and the ball screw 17 is rotated according to the rotation of the servo motor. The ball screw 17 is screwed to the moving shaft 25 of the pressing portion 19, and the moving shaft 25 is moved up and down in the direction of the arrow X in the drawing according to the rotation of the ball screw 17, that is, the rotation of the servo motor 13. A caulking punch 21 and a pressure-sensitive sensor 23 are stacked on the lower portion of the moving shaft 25, and the pressing force P applied to the caulking punch 21 by the pressure-sensitive sensor 23 can be measured.

  A table 31 is disposed below the pressing portion 19, and a work 33, which is a base plate on which a caulking member is caulked by a caulking member, is mounted on the table 31.

  The control unit 11 outputs a motor drive signal 13a to drive the servo motor 13, and calculates and detects the movement amount of the pressing unit 19 from the rotation amount of the servo motor 13 and the feed pitch of the ball screw 17. Further, the pressure signal 23 a from the pressure sensor 23 is received, and the pressing force P applied to the caulking punch 21 is detected. Here, the control unit 11 and the pressure sensor 23 function as a pressing force detection unit in the present invention, and the control unit 11 functions as a movement amount detection unit in the present invention.

  Next, the configuration in the vicinity of the caulking punch 21 and the workpiece 33 will be described with reference to FIG. FIG. 2 is a schematic diagram showing a configuration in the vicinity of the caulking punch 21 and the work 33.

  In FIG. 2, a lower end of a caulking member 41 having a constricted portion 47 is press-fitted into the work 33 on the table 31. A linear caulking member 51 (for example, the above-described SMA wire) is fed by a chuck member (not shown) at one end and a wire rod with a tension adjusting function (not shown) at the other end so as to be hooked on the constricted portion 47 of the caulking member 41. The portion is held in a state where a predetermined tension is applied.

  A concave portion 25 a is provided in the lower portion of the moving shaft 25, and a caulking punch 21 and a pressure-sensitive sensor 23 are stacked in the concave portion 25 a, and a push applied to the caulking punch 21 by the pressure-sensitive sensor 23. The pressure P can be measured. The tip of the caulking punch 21 is in contact with the head of the caulking member 41, and the caulking member 41 is deformed by the pressing force P, and the caulking member 51 is fixed to the work 33.

  Next, the relationship between the amount of movement of the pressing portion 19 and the pressing force during caulking will be described with reference to FIG. FIG. 3 is a schematic diagram showing the relationship between the movement amount S of the pressing portion 19 during caulking, that is, the deformation amount S of the caulking member 41 and the pressing force P. FIGS. 3 (a) to 3 (e) are caulking. FIG. 3 (f) is a graph showing the relationship between the movement amount S of the pressing portion 19, that is, the deformation amount S of the caulking member 41 and the pressing force P. FIG.

  3A, the caulking member 41 is a bar composed of a head portion 43, a tapered portion 45, a constricted portion 47, a trunk portion 49, and the like. As described with reference to FIG. Is pressed into the work 33 and fixed. The caulking member 51 (for example, the above-described SMA wire) is disposed so as to contact the constricted portion 47 of the caulking member 41. This state is defined as (a) in FIG.

  In FIG. 3B, when the caulking member 41 receives the pressing force P applied from the caulking punch 21 of the pressing portion 19, the stress received by the constricted portion 47 having a small diameter increases. Starts to transform. This state is shown in (b) of FIG.

  In FIG. 3C, when the deformation progresses and the constricted portion 47 is almost completely deformed, the deformation form of the caulking member 41 is changed, and then the entire caulking member 41 starts to deform. At this time, since the cross-sectional area of the caulking member 41 is larger than that of the constricted portion 47, the pressing force P necessary for the deformation of the caulking member 41 is increased, and the change in the deformation amount S of the caulking member 41 with respect to the change in the pressing force P is increased. The rate is small. Alternatively, the rate of change of the pressing force P with respect to the change in the deformation amount S of the caulking member 41 is increased. This state is (c) in FIG. 3 (f), and this change is an inflection point W at which the relationship between the pressing force P and the deformation amount S of the caulking member 41 shown in the graph of FIG. Can be detected. As shown in FIG. 3F, it is assumed that the deformation amount S = Sw and the pressing force P = Pw at the inflection point W.

  In addition, since the deformation | transformation of the crimping member 41 mentioned above is mainly plastic deformation, the relationship between the pressing force P and the deformation amount S does not necessarily show the linearity as shown in FIG. However, even in the case of plastic deformation, the relationship between the pressing force P and the deformation amount S is that the caulking member 41 is deformed from the state in which the constricted portion 47 is mainly deformed to the state in which the entire caulking member 41 is deformed as described above. Inflection points can be detected because of the large change at the point where.

  In FIG. 3D, in the state immediately after the inflection point W in FIG. 3C, the caulking state in which sufficient holding and fixing of the caulking member 51 is not yet obtained. Therefore, in order to obtain an appropriate caulking state B, the state in which the deformation amount S of the caulking member 41 is further deformed by a predetermined deformation amount ΔSb from the state of FIG. 3C, or the pressing force P changes to a predetermined pressing force. The deformation must proceed until the pressure is further increased by the amount ΔPb. This state is (d) in FIG. As shown in FIG. 3F, it is assumed that the deformation amount S = Sb = Sw + ΔSb and the pressing force P = Pb = Pw + ΔPb in an appropriate caulking state B.

  The proper caulking state B mentioned here means that the caulking part 51 does not loosen or come off due to insufficient holding force of the caulking part in actual use, including durability operation, and the caulking member 51 is damaged due to excessive caulking. This refers to a state where there is no problem such as disconnection. In other words, the caulking member 51 is held at a predetermined holding force amount or more, and the deformation of the caulking member 51 is within a predetermined amount.

  In FIG. 3 (e), when the deformation further proceeds from the appropriate caulking state B in FIG. 3 (d), not only the deformation of the entire caulking member 41 further proceeds, but also the deformation of the caulking member 51 proceeds. The member 51 is in a state where damage remains. This state is (e) in FIG. As described above, if damage remains in the caulking member 51, it will adversely affect durability such as disconnection during actual use, so that the state shown in FIG. It is necessary to stop the caulking in the proper caulking state B.

  As described above, by controlling the caulking to an appropriate caulking state B shown in FIG. 3D, the diameter of 10 μm or more and 1 mm or less that has been used as an actuator in recent years as well as a general wire rod is used. Even in the case of SMA wire caulking with a thin wire diameter, it is possible to caulk so as not to cause disconnection due to SMA wire disconnection or operation durability in a state where a constant tension is applied to the SMA wire.

  Next, a first embodiment of the caulking device of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram showing a detailed configuration of the control unit 11 in the first embodiment of the caulking device 1 shown in FIG. 1, and FIG. 5 is a flowchart showing the operation of the first embodiment. .

  4, the control unit 11 of the caulking apparatus 1 includes a CPU 110, a motor driving unit 211, a ROM (Read Only Memory) 213, a parameter storage unit 214, a RAM (Random Access Memory) 215, and the like.

  The CPU 110 expands and executes a program stored in advance in the ROM 213 on the RAM 215, thereby executing the parameter reading unit 111, the motor drive control unit 112, the current detection unit 113, the inflection point detection unit 114, and the movement amount detection unit 115. Also, it functions as the movement amount control unit 116 and the like.

  The motor drive unit 211 outputs a motor drive signal 13a to drive the servo motor 13 in FIG. The ROM 213 stores a program for controlling the caulking device 1 in advance.

  The parameter storage unit 214 is configured by a PROM (Programmable ROM) or the like, and from a predetermined value ΔIw of a change amount of torque current for detecting an inflection point W described later in FIG. Parameters such as a predetermined deformation amount ΔSb up to the proper caulking state B are stored in advance. Parameters such as ΔIw and ΔSb may be stored in the ROM 213 in advance, or may be set by a numeric keypad, a dial-type preset unit or the like without using a memory.

  The parameter reading unit 111 of the CPU 110 reads from the parameter storage unit 214 a predetermined value ΔIw of the amount of change in torque current for detecting the inflection point W stored in advance, or from the inflection point W to the appropriate caulking state B. Parameters such as a predetermined deformation amount ΔSb are read out and stored in a predetermined area on the RAM 215. The motor drive control unit 112 controls the motor drive unit 211 to output a motor drive signal 13a, and drives the servo motor 13 of FIG. The current detection unit 113 detects a torque current It flowing through the servo motor 13.

  The inflection point detection unit 114 is a predetermined value of the torque current change amount ΔIt detected by the current detection unit 112 and the torque current change amount for detecting the inflection point W read by the parameter reading unit 111. By comparing with ΔIw, the inflection point W shown in FIG. 3F is detected. Details will be described with reference to FIG.

  The movement amount detection unit 115 is based on the rotation amount of the servo motor 13 controlled by the motor drive control unit 112 and the feed pitch of the ball screw 17. A deformation amount ΔS from the inflection point W is calculated and detected. Here, the movement amount detection unit 115 and the motor drive control unit 112 function as movement amount detection means in the present invention.

  The movement amount control unit 116 drives the servo motor 13 until the movement amount ΔS detected by the movement amount detection unit 115 becomes equal to the predetermined deformation amount ΔSb read by the parameter reading unit 111. By the way, the drive of the servo motor 13 is controlled via the motor drive control part 112 and the motor drive part 211 so that it may stop.

  5, in step S101, the parameter reading unit 111 of the CPU 110 detects a predetermined value ΔIw of the change amount of the torque current It for detecting the inflection point W stored in the parameter storage unit 214 in advance, or the inflection point W. To a proper caulking state B, parameters such as a predetermined deformation amount ΔSb are read out and stored in a predetermined area on the RAM 215 (parameter reading step).

  In step S103, the motor drive control unit 112 controls the motor drive unit 211 to output the motor drive signal 13a, and the drive of the servo motor 13 is started (pressing process). The servo motor 13 is rotated at a constant speed, and the pressing portion 19 also descends at a constant speed as the servo motor 13 rotates.

  In step S111, the current detection unit 113 detects the torque current It flowing through the servo motor 13 (current detection step).

  In step S113, the inflection point detecting unit 114 determines whether or not the rate of change ΔIt of the torque current It is greater than the predetermined value ΔIw read in step S101, that is, whether or not the inflection point W has been reached. Confirmed (inflection point detection step). If the value is equal to or less than the predetermined value (step S113; No), the process returns to step S111 and steps S111 and S113 are repeated.

  The principle of inflection point detection described above is as follows. In the state up to the inflection point W where the constricted portion 47 of the caulking member 41 is deformed (the state shown in FIG. 3B), the torque current It is almost constant, but the servo motor approaches the inflection point W. Since the drive load 13 increases, the torque current It increases rapidly. Therefore, the inflection point W can be detected as a point at which the rate of change of the torque current It is greater than a predetermined value.

  Originally, the change rate ΔIt of the torque current It needs to be obtained as the change rate of the torque current It per unit time. Here, it is assumed that the detection operation of torque current It (repetition of steps S111 and S113) is repeated almost every constant time, and torque current It (current) detected in current step S111 is detected in previous step S111. The increment from the torque current It (previous) is regarded as the change rate ΔIt.

  When the rate of change ΔIt of the torque current It becomes larger than the predetermined value ΔIw (step S113; Yes), in step S121, the movement amount detection unit 115 calculates the rotation amount of the servo motor 13 and the feed pitch of the ball screw 17 from A movement amount ΔS from the inflection point W of the pressing portion 19 is detected (movement amount detection step). In step S123, the movement amount control unit 116 confirms whether or not the movement amount ΔS from the inflection point W of the pressing unit 19 is greater than or equal to the predetermined movement amount ΔSb (movement amount confirmation step). When it is smaller than the predetermined movement amount ΔSb (step S123; No), the process returns to step S121, and steps S121 and S123 are repeated.

  When the movement amount is larger than or equal to the predetermined movement amount ΔSb (step S123; Yes), in step S131, the movement amount control unit 116 controls the motor driving unit 211 via the motor driving control unit 112, and the servo motor 13 is moved. The operation is stopped (pressing stop process), and the caulking operation is completed.

  As described above, according to the first embodiment, the inflection point W is detected from the rate of change ΔIt of the torque current It of the servo motor 13 and the pressing portion 19 is moved from the inflection point W by a predetermined movement amount ΔSb. By further moving, it is possible to provide a caulking apparatus that can realize an appropriate caulking state B and can reduce caulking defects due to variations in the mechanical characteristics and component dimensions of the caulking member material.

  In the first embodiment described above, the inflection point W is detected from the rate of change ΔIt of the torque current It of the servo motor 13, but instead, the servo is detected using the movement amount detection unit 115 described above. The movement amount S of the pressing portion 19 is calculated from the rotation amount of the motor 13 and the feed pitch of the ball screw 17, and the press of the caulking punch 21 is determined from the pressure signal 23a of the pressure sensor 23 as described later in the second embodiment. The pressure P may be detected, and the inflection point W shown in FIG. 3F may be obtained from the relationship between the movement amount S and the pressing force P.

  Next, a second embodiment of the caulking device of the present invention will be described with reference to FIGS. FIG. 6 is a block diagram showing a detailed configuration of the control unit 11 in the second embodiment of the caulking device 1 shown in FIG. 1, and FIG. 7 is a flowchart showing the operation of the second embodiment. .

  In FIG. 6, the control unit 11 of the caulking apparatus 1 includes a CPU 120, a motor driving unit 211, a ROM 213, a parameter storage unit 214, a RAM 215, a pressing force detection unit 217, and the like.

  The CPU 120 develops and executes a program stored in advance in the ROM 213 on the RAM 215, thereby executing a parameter reading unit 121, a motor drive control unit 112, a current detection unit 113, an inflection point detection unit 114, and a pressing force detection control unit. 125 and the pressing force control unit 126.

  The motor drive unit 211 outputs a motor drive signal 13a to drive the servo motor 13 in FIG. The ROM 213 stores a program for controlling the caulking device 1 in advance.

  The parameter storage unit 214 is composed of a PROM (Programmable ROM) or the like, and from the inflection point W shown in FIG. 3 or the predetermined value ΔIw of the change amount of the torque current for detecting the inflection point W described in FIG. Parameters such as a change amount ΔPb of a predetermined pressing force up to an appropriate caulking state B are stored in advance. Parameters such as ΔIw and ΔPb may be stored in advance in the ROM 213, or may be set using a numeric keypad, a dial type preset means, or the like without using a memory.

  The pressing force detection unit 217 receives the pressure signal 23 a of the pressure sensor 23 and detects the change ΔP in the pressing force from the inflection point W.

  The parameter reading unit 121 of the CPU 120 has a predetermined value ΔIw of the amount of change in torque current for detecting the inflection point W stored in advance in the parameter storage unit 214 and a predetermined value from the inflection point W to the appropriate caulking state B. Are read out and stored in a predetermined area on the RAM 215. The motor drive control unit 112, the current detection unit 113, and the inflection point detection unit 114 are the same as those in the first embodiment shown in FIG.

  The pressing force detection control unit 125 receives the pressure signal 23a of the pressure sensor 23 via the pressing force detection unit 217, and calculates and detects the change ΔP in the pressing force from the inflection point W. Here, the pressure sensor 23, the pressing force detection unit 217, and the pressing force detection control unit 125 function as a pressing force detection unit in the present invention.

  In the pressing force control unit 126, the change ΔP in the pressing force from the inflection point W detected by the pressing force detection control unit 125 is equal to the predetermined change ΔPb in the pressing force read by the parameter reading unit 121. Until the servo motor 13 is driven, the drive of the servo motor 13 is controlled via the motor drive control unit 112 and the motor drive unit 211 so that the servo motor 13 is stopped at the same time.

  In FIG. 7, in step S201, the parameter reading unit 111 of the CPU 120 performs appropriate caulking from the predetermined value ΔIw of the torque current change amount for detecting the inflection point W stored in the RAM 215 or the inflection point W. Parameters such as a change amount ΔPb of a predetermined pressing force up to the state B are read and stored in a predetermined area on the RAM 215 (parameter reading step). Steps S103 to S113 are the same as those in the first embodiment shown in FIG.

  When the rate of change ΔIt of the torque current It becomes larger than the predetermined value ΔIw (step S113; Yes), the pressure sensor 23 controls the pressure sensor 23 through the pressing force detection unit 217 by the pressing force detection control unit 125 in step S221. A change ΔP in the pressing force from the inflection point W is detected from the pressure signal 23a (pressing force detection step).

  In step S223, the pressing force control unit 126 checks whether or not the pressing force change ΔP from the inflection point W is greater than or equal to a predetermined pressing force change ΔPb (pressing force checking step). ). When it is smaller than the predetermined change amount ΔPb of the pressing force (step S153; No), the process returns to step S221, and steps S221 and S223 are repeated.

  If it is greater than or equal to the predetermined change amount ΔPb of the pressing force (step S223; Yes), the motor driving unit 211 is controlled by the pressing force control unit 126 via the motor driving control unit 112 in step S131, and the servo The motor 13 is stopped (pressing stop process), and the caulking operation is finished.

  As described above, according to the second embodiment, the inflection point W is detected from the rate of change ΔIt of the torque current It of the servo motor 13, and a predetermined pressing from the inflection point W to the appropriate caulking state B is performed. A caulking device capable of realizing an appropriate caulking state B by further pressurizing the pressing force P by the pressure change amount ΔPb and reducing caulking defects due to variations in the mechanical characteristics of the caulking member material and component dimensions. Can be provided.

  Next, a third embodiment of the caulking device of the present invention will be described with reference to FIGS. FIG. 8 is a block diagram showing a third embodiment of the caulking device 1 of the present invention, FIG. 9 is a block diagram showing a detailed configuration of the control unit 11 in the third embodiment, and FIG. It is a flowchart which shows operation | movement of this embodiment.

  In FIG. 8, the caulking device 1 includes a control unit 11, a hydraulic cylinder 61, a pressing unit 19, a position sensor 63, a table 31, and the like. The pressing unit 19 includes a caulking punch 21, a pressure sensor 23, a moving shaft 25, and the like. A work 33 is arranged on the table 31. Here, the control unit 11 and the hydraulic cylinder 61 function as drive means in the present invention, and the control unit 11 and the position sensor 63 function as movement amount detection means.

  The hydraulic cylinder 61 has an action portion 61a. The action portion 61a is coupled to the moving shaft 25 of the pressing portion 19, and the moving shaft 25 is moved up and down in the direction of the arrow X in the drawing as the action portion 61a is driven. The action part 61a is driven so that the pressing force increases in proportion to time, for example. The movement amount S of the moving shaft 25, that is, the movement amount S of the pressing unit 19, is detected by the position sensor 63 and transmitted to the control unit 11 as a position signal 63a. The other configuration is the same as that shown in FIG.

  In FIG. 9, the control unit 11 includes a CPU 130, a ROM 213, a parameter storage unit 214, a RAM 215, a cylinder driving unit 221, a pressing force detection unit 217, a movement amount detection unit 219, and the like.

  The CPU 130 develops and executes a program stored in advance in the ROM 213 on the RAM 215, thereby executing the parameter reading unit 131, the cylinder drive control unit 132, the movement amount detection control unit 133, the pressing force detection control unit 125, the inflection inspection. It functions as the exit part 134, the movement amount control part 136 and the like. Instead of the movement amount control unit 136, it may function as the pressing force control unit 126.

  The cylinder driving unit 221 outputs a cylinder driving signal 61b to drive the hydraulic cylinder 61 in FIG. The ROM 213 stores a program for controlling the caulking device 1 in advance.

  The parameter storage unit 214 is composed of a PROM (Programmable ROM) or the like, and a predetermined value ΔSw / ΔPw of the ratio of the moving amount of the pressing unit 19 and the pressing force for detecting an inflection point W described later in FIG. Parameters such as a predetermined deformation amount ΔSb from the inflection point W shown in 3 to the appropriate caulking state B are stored in advance. Parameters such as ΔSw / ΔPw and ΔSb may be stored in the ROM 213 in advance, or may be set using a numeric keypad, a dial type preset means, or the like without using a memory.

  The movement amount detection unit 219 receives the position signal 63 a of the position sensor 63 and detects the movement amount S of the pressing unit 19. The pressing force detection unit 217 receives the pressure signal 23 a of the pressure sensor 23 and detects the pressing force P applied to the caulking punch 21.

  The parameter reading unit 131 of the CPU 130 shows a predetermined value ΔSw / ΔPw of the ratio between the moving amount of the pressing unit 19 and the pressing force for detecting the inflection point W stored in advance in the parameter storage unit 214, as shown in FIG. Parameters such as a predetermined deformation amount ΔSb from the inflection point W to an appropriate caulking state B are read and stored in a predetermined area on the RAM 215. The cylinder drive control unit 132 controls the cylinder drive unit 221 to output a cylinder drive signal 61b, and drives the hydraulic cylinder 61 in FIG.

  The movement amount detection control unit 133 receives the position signal 63 a of the position sensor 63 via the movement amount detection unit 219 and detects the movement amount S of the pressing unit 19. Here, the position sensor 63, the movement amount detection unit 219, and the movement amount detection control unit 133 function as movement amount detection means in the present invention. The pressing force detection control unit 125 is the same as that shown in the second embodiment in FIG.

  The inflection point detection unit 134 is based on the movement amount S of the pressing unit 19 detected by the movement amount detection control unit 133 and the pressing force P applied to the caulking punch 21 detected by the pressing force detection control unit 125. The inflection point W shown in FIG. 3 (f) is detected.

  The movement amount control unit 136 includes the hydraulic cylinder 61 until the movement amount ΔS from the inflection point W detected by the movement amount detection control unit 133 becomes equal to the predetermined deformation amount ΔSb read by the parameter reading unit 131. The hydraulic cylinder 61 is controlled to be driven via the cylinder drive control unit 132 and the cylinder drive unit 221 so as to stop at the same time.

  When the CPU 130 functions as the pressing force control unit 126 instead of the movement amount control unit 136, the parameter reading unit 131 causes the parameter reading unit 131 to replace the predetermined deformation amount ΔSb from the inflection point W to the appropriate crimped state B. The change amount ΔPb of the predetermined pressing force from the inflection point W is read out.

  Then, the pressing force control unit 126 determines the amount of change ΔPb in the pressing force from the inflection point W detected by the pressing force detection control unit 125 from the predetermined amount ΔPb of the pressing force read by the parameter reading unit 131. The hydraulic cylinder 61 is driven until it becomes equal to, and the drive of the hydraulic cylinder 61 is controlled via the cylinder drive control unit 132 and the cylinder drive unit 221 so as to stop when it becomes equal.

  In FIG. 10, in step S301, the parameter reading unit 131 of the CPU 130 detects a predetermined value ΔSw / ΔPw of the ratio between the moving amount of the pressing unit 19 and the pressing force for detecting the inflection point W stored in the RAM 215 in advance. Then, parameters such as a predetermined deformation amount ΔSb from the inflection point W shown in FIG. 3 to the appropriate caulking state B are read (parameter reading step).

  In step S303, the cylinder drive control unit 132 controls the cylinder drive unit 221 to output the cylinder drive signal 61b, the drive of the hydraulic cylinder 61 in FIG. Lower (pressing process).

  In step S311, the movement amount detection control unit 133 detects the movement amount S of the pressing unit 19 from the position signal 63a of the position sensor 63 via the movement amount detection unit 219 (movement amount detection step). In step S313, the pressing force detection control unit 125 detects the pressing force P applied to the caulking punch 21 from the pressure signal 23a of the pressure sensor 23 via the pressing force detection unit 217 (pressing force detection step). .

  In step S315, it is confirmed from the movement amount S detected in step S311 and the pressing force P detected in step S313 whether the current caulking state is the inflection point W in FIG. (Inflection point detection process). When it is determined that the point is not an inflection point (step S315; No), the process returns to step S311 and steps S311, S313, and S315 are repeated.

  Whether or not the current caulking state is the inflection point W in FIG. 3 (f) is determined by repeating steps S311 to S315, as shown in FIG. 3 (f), the previous step S311 and the current step. The ratio ΔS / ΔP between the change amount ΔS of the movement amount S of the pressing portion 19 relative to S311 and the change amount ΔP of the pressing force P between the previous step S313 and the current step S313 is smaller than the predetermined value ΔSw / ΔPw. Whether or not the change in the movement amount S with respect to the change in the pressing force P is small.

  In addition, while step S311 is repeated, it is determined whether or not the time change rate ΔS / Δt of the movement amount S of the pressing portion 19 between the previous step S311 and the current step S311 is smaller than a predetermined value ΔSw / Δt. You can also Alternatively, it is possible to determine whether or not the time change rate ΔP / Δt of the pressing force P between the previous step S313 and the current step S313 is larger than the predetermined value ΔPw / Δt while step S313 is repeated.

  If it is determined that the point is an inflection point (step S315; Yes), the process proceeds to step S121. Steps S121 and S123 are the same as those in the first embodiment shown in FIG.

  If the movement amount ΔS of the pressing portion 19 from the inflection point W is greater than or equal to the predetermined movement amount ΔSb in step S123 (step S123; Yes), the movement amount control unit 136 controls the cylinder drive in step S331. The cylinder driving unit 221 is controlled via the unit 132, the hydraulic cylinder 61 is stopped (pressing stop process), and the caulking operation is finished.

  Note that the same effect can be obtained by using step S221 and step S223 shown in the second embodiment in FIG. 7 instead of step S121 and step S123.

  As described above, according to the third embodiment, the inflection point W is detected from the movement amount S of the pressing portion 19 and the pressing force P applied to the caulking punch 21, and the appropriate inflection point W is detected. The pressing portion 19 is further moved by a predetermined movement amount ΔSb up to the caulking state B, or the pressing force P is increased by a predetermined pressing force change amount ΔPb from the inflection point W to the appropriate caulking state B. Thus, it is possible to provide a caulking device that can realize an appropriate caulking state B and can reduce caulking defects due to variations in the mechanical characteristics and component dimensions of the caulking member material.

  Next, another example of the caulking member and the caulking member will be described with reference to FIG. FIG. 11 is a schematic diagram illustrating another example of the caulking member and the caulking member.

  In the caulking of the present invention, the caulking state can be grasped if the inflection point W described above can be detected. Therefore, the caulking member has a deformed portion for deforming first and is deformed by the deformation of the deforming portion. As long as the caulking member can be sandwiched and held and fixed, the bar may have any shape as long as it is not a bar having a constricted portion as shown in FIG. Further, the caulking member may have any shape as long as the caulking member can be held and fixed by being clamped by the caulking member.

  In FIG. 11, the caulking member 71 is, for example, a metal flat plate. The caulking member 53 is a flat plate member such as a SMA plate or foil, or a shim plate of a bimorph piezoelectric element.

  In the caulking in this example, as shown in FIG. 11A, the caulking member 53 is sandwiched between the caulking members 71 that are bent in advance by the deformable portion 71 a, and the bent portion 71 b of the caulking member 71 is pressed by the caulking punch 21. Go. Then, as shown in FIG. 11B, when the bent portion 71b of the caulking member 71 completely contacts the caulking member 53, the deformation of the deforming portion 71a is almost completed.

  Thereafter, by further applying a pressing force with the caulking punch 21, the caulking member 71 is compressed and deformed, and the caulking member 53 is sandwiched between the caulking members 71 and held and fixed. At this time, as shown in FIG. 3 (f), an inflection point W is obtained, and further caulking from the inflection point W by a predetermined amount of movement ΔSb or a predetermined amount of change ΔPb of the pressing force, thereby achieving an appropriate caulking state. B can be obtained. When the pressing force is further increased, compression deformation of the caulking member 53, caulking into the caulking member 71, and the like occur, which causes caulking failure.

  As described above, even in a caulking member and a caulking member having an arbitrary shape, an inflection point of the relationship between the moving amount of the pressing portion and the pressing force is detected, and a predetermined moving amount or a predetermined pressing force is detected from the inflection point. Further, it is possible to provide a caulking apparatus that can obtain an appropriate caulking state by further caulking, and can reduce caulking defects due to variations in the mechanical properties and component dimensions of the caulking member material.

  As described above, according to the present invention, the point at which the deformation form of the caulking member changes during caulking is detected as an inflection point, and an appropriate point is determined from the inflection point stored in advance. The pressing portion is moved or pressurized by the amount of movement or pressing force of the pressing portion for caulking up to the caulking state. As a result, it is possible to provide a caulking device that can reduce caulking defects due to variations in the mechanical characteristics and component dimensions of the caulking member material.

  It should be noted that the detailed configuration and detailed operation of each component constituting the caulking device according to the present invention can be changed as appropriate without departing from the spirit of the present invention.

It is a schematic diagram which shows the outline of the crimping apparatus of this invention. It is a schematic diagram which shows the structure of a caulking punch and a workpiece | work vicinity. It is a schematic diagram which shows the relationship between the movement amount of the press part at the time of caulking, and the pressing force P. FIG. It is a block diagram which shows the structure of the detail of the control part in 1st Embodiment of a crimping apparatus. It is a flowchart which shows operation | movement of 1st Embodiment of a crimping apparatus. It is a block diagram which shows the structure of the detail of the control part in 2nd Embodiment of a crimping apparatus. It is a flowchart which shows operation | movement of 2nd Embodiment of a crimping apparatus. It is a block diagram which shows 3rd Embodiment of a crimping apparatus. It is a block diagram which shows the structure of the detail of the control part in 3rd Embodiment of a crimping apparatus. It is a flowchart which shows operation | movement of 3rd Embodiment of a crimping apparatus. It is a schematic diagram which shows the other example of a caulking member and a caulking member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Caulking device 11 Control part 13 Servo motor 13a Motor drive signal 15 Coupling 17 Ball screw 19 Press part 21 Caulking punch 23 Pressure sensor 23a Pressure signal 25 Moving shaft 31 Table 33 Work piece 41 Caulking member 43 Head part 45 Taper part 47 Constriction part 49 body 51 caulking member 53 caulking member 61 hydraulic cylinder 61a (hydraulic cylinder) action part 61b cylinder drive signal 63 position sensor 71 caulking member 71a deforming part 71b (one end of caulking member 71) 110, 120, 130 CPU
111, 121, 131 Parameter reading unit 112 Motor drive control unit 113 Current detection unit 114, 134 Inflection point detection unit 115 Movement amount detection unit 116, 136 Movement amount control unit 125 Pressing force detection control unit 126 Pressing force control unit 132 Cylinder Drive control unit 133 Movement amount detection control unit 211 Motor drive unit 213 ROM
215 RAM
217 Pressing force detection unit 219 Movement amount detection unit 221 Cylinder driving unit W Inflection point B Proper caulking state S Movement amount (of pressing unit 19) or deformation amount (caulking member 41) ΔS Movement from inflection point W Amount ΔSb predetermined movement amount or predetermined deformation amount P pressing force ΔP amount of change in pressing force from the inflection point W ΔPb amount of change in predetermined pressing force

Claims (6)

A pressing portion that applies a pressing force to the caulking member by movement, deforms the caulking member, and fixes the caulking member;
Driving means for moving the pressing portion;
In the caulking device including the pressing unit and a control unit that controls the operation of the driving unit,
A movement amount detecting means for detecting a movement amount of the pressing portion;
The controller is
In the process of applying the pressing force by the pressing unit, an inflection point detection unit that detects an inflection point at which the deformation form of the caulking member changes;
A parameter storage unit that stores in advance a difference between the amount of movement of the pressing unit at the inflection point and the amount of movement of the pressing unit in an appropriate crimped state as a predetermined deformation amount;
A parameter reading unit for reading the predetermined deformation amount stored in the parameter storage unit;
A moving amount for moving the pressing portion to an appropriate caulking position by comparing the moving amount of the pressing portion detected by the moving amount detecting means with the predetermined deformation amount read by the parameter reading portion. have a control unit,
The caulking member is
A bar having a constricted portion and a head having a cross section perpendicular to the pressing direction and having a cross-sectional area larger than that of the constricted portion, and having a deformed portion that deforms first in the caulking process, The deforming portion to be deformed is the constricted portion, and the caulking member is sandwiched by deformation of the deforming portion to hold and fix the caulking member,
The caulking member is
A caulking device characterized by being a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less . A pressing portion that applies a pressing force to the caulking member by movement, deforms the caulking member, and fixes the caulking member;
Driving means for moving the pressing portion;
In the caulking device including the pressing unit and a control unit that controls the operation of the driving unit,
A pressing force detecting means for detecting the pressing force;
The controller is
In the process of applying the pressing force by the pressing unit, an inflection point detection unit that detects an inflection point at which the deformation form of the caulking member changes;
A parameter storage unit that stores in advance a difference between the pressing force at the inflection point and the pressing force in an appropriate caulking state as a change amount of a predetermined pressing force;
A parameter reading unit for reading a change amount of the predetermined pressing force stored in the parameter storage unit;
A pressing force that pressurizes the pressing portion to an appropriate caulking state by comparing the pressing force detected by the pressing force detecting means with a change amount of the predetermined pressing force read by the parameter reading portion. have a control unit,
The caulking member is
A bar having a constricted portion and a head having a cross section perpendicular to the pressing direction and having a cross-sectional area larger than that of the constricted portion, and having a deformed portion that deforms first in the caulking process, The deforming portion to be deformed is the constricted portion, and the caulking member is sandwiched by deformation of the deforming portion to hold and fix the caulking member,
The caulking member is
A caulking device characterized by being a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less . The caulking device according to claim 1, wherein the inflection point is a point at which a change rate of a movement amount of the pressing portion with respect to a change in the pressing force is equal to or less than a predetermined value. The caulking device according to claim 2, wherein the inflection point is a point at which a rate of change of the pressing force with respect to a change in the amount of movement of the pressing portion becomes a predetermined value or more.   A caulking method for applying a pressing force to a caulking member and deforming the caulking member to fix the caulking member,
  The caulking member is
A bar having a constricted portion and a head having a cross-sectional area larger than the cross-sectional area of the constricted portion in a cross section perpendicular to the pressing direction;
  The caulking member is
It is a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less,
  An arranging step for arranging the shape memory alloy of the wire to contact the constricted portion;
  A pressing step of deforming the constricted portion by moving a pressing portion that applies the pressing force to the caulking member;
  An inflection point detecting step of detecting an inflection point at which the deformation form of the caulking member changes in the process of applying the pressing force;
  A parameter storage step for storing in advance a difference between the amount of movement of the pressing portion at the inflection point and the amount of movement of the pressing portion in an appropriate crimped state as a predetermined deformation amount;
  A parameter reading step of reading the stored predetermined deformation amount;
  A movement amount detection step of detecting a movement amount of the pressing portion;
  A movement amount control step of comparing the detected movement amount of the pressing portion with the predetermined deformation amount read by the parameter reading step, and moving the pressing portion to an appropriate caulking position;
A caulking method characterized by comprising:   A caulking method for applying a pressing force to a caulking member and deforming the caulking member to fix the caulking member,
  The caulking member is
A bar having a constricted portion and a head having a cross-sectional area larger than the cross-sectional area of the constricted portion in a cross section perpendicular to the pressing direction;
  The caulking member is
It is a shape memory alloy of a wire having a diameter of 10 μm or more and 1 mm or less,
  An arranging step for arranging the shape memory alloy of the wire to contact the constricted portion;
  A pressing step of deforming the constricted portion by moving a pressing portion that applies the pressing force to the caulking member;
  An inflection point detecting step of detecting an inflection point at which the deformation form of the caulking member changes in the process of applying the pressing force;
  A parameter storage step for storing in advance a difference between the amount of movement of the pressing portion at the inflection point and the amount of movement of the pressing portion in an appropriate crimped state as a predetermined deformation amount;
  A parameter reading step of reading the stored predetermined deformation amount;
  A pressing force detecting step for detecting the pressing force;
  A pressing force control step of comparing the detected pressing force with the change amount of the predetermined pressing force read by the parameter reading step and pressurizing the pressing portion to an appropriate caulking state;
A caulking method characterized by comprising:

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