JP2007203307A - Joining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining apparatus which can hold objects to be joined with a predetermined gripping force even when the state of the objects to be joined fluctuates. <P>SOLUTION: A control means 73 detects a pushing force, applied on the objects 9 to be joined from a clamping rod 53, by means of a clamping load-cell 80a, and controls a clamping servomotor 55 based on the detected pushing force such that the pushing force of the clamping rod 53 applied on the objects 9 to be joined becomes a predetermined force. By this method, the objects 9 to be joined can be gripped by the predetermined gripping force irrespective of the position where the objects 9 to be joined is arranged, the thickness of the objects 9 to be joined, and the existence of the clearance between respective joining members 2, 3. Further, even when a rivet 1 deeply plunges, the objects 9 to be joined are not gripped by an excessive force. As a result, the joining operation can be carried out in the state that the objects to be joined have been gripped by an suitable gripping force, and the joining quality can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joining device that joins a plurality of joining members. For example, the present invention relates to a joining device that pushes and joins a punch rivet to an object to be joined.

  FIG. 45 is a cross-sectional view showing a partial configuration of the conventional striking device 10. The striking device 10 immerses the punch rivet 17 in the workpiece 18 on which the joining members 19 and 20 are stacked, and physically joins the joining members 19 and 20. The punch rivet 17 may be referred to as a driving rivet or a self piercing rivet (abbreviated as SPR) (see, for example, Patent Documents 1 to 4).

  The striking device 10 includes a die 12, a clamp body 13, a punch 14, and a spring body 15. The hammering device 10 cooperates with the die 12 and the clamp body 13 to sandwich the workpiece 18 and pushes the rivet 17 into the workpiece 18 with the punch 14.

  The clamp body 13 is elastically connected to the punch 14 by a spring body 15. When the punch 14 is moved toward the workpiece 18, the clamp body 13 is also moved toward the workpiece 18 together with the punch 14. In the clamp body 13, the punch 14 approaches the die 12, and the pressing force P <b> 1 that presses the workpiece 18 increases.

US Pat. No. 6,276,050 US Patent Application Publication No. 2001-3859 US Patent Application Publication No. 2001-39718 US Patent Application Publication No. 2001-27597

  In the clamp body 13 of the striking device 10, the pressing force P <b> 1 that presses the workpiece 18 changes as the punch 14 moves. Moreover, it is difficult to adjust the pressing force P1 that presses the workpiece 18 to a predetermined value. Furthermore, when the dimension and position of the workpiece 18 vary, the pressing force P1 applied to the workpiece 18 also changes.

  When the pressing force P1 varies, the clamping force for clamping the workpiece 18 cannot be kept constant. For example, when the clamping force is small, the workpiece 18 is displaced during the joining process. In addition, when the clamping force is large, the workpiece 18 is deformed.

  The prior art striking device 10 applies a pressing force to the workpiece 18 so that the gap is eliminated by the clamp body 13 in consideration of a case where a gap is formed between the joining members 18. When the strength of the workpiece 18 is small, the workpiece 18 may be damaged by the pressing force applied by the clamp body 13. In particular, since the pressing force of the clamp body 13 increases as the punch 14 moves, a large pressing force is applied to the workpiece 18 at the end of the rivet immersion operation. As described above, the conventional striking device 10 has a problem that it is difficult to adjust the pressing force of the clamp body 13 and the joining quality of the joining members 19 and 20 to be joined is deteriorated.

  Further, in order to teach the joining position 21 to the striking device 10, it is necessary for the operator to confirm the contact state between the punch 14 and the workpiece 18. In the contact state, a large pressing force is applied to the workpiece 18 by the clamp body 13. Therefore, the worker needs to check the contact state carefully and carefully in order to safely perform the teaching work. Further, the punch 14 needs to be displaced against the spring force of the spring body 15, and there is a problem that the punch driving means for driving the punch 14 to be displaced is increased in size.

  The problems as described above are common problems in a joining apparatus in which an object to be joined is sandwiched between a clamp body and a support body, and the processing means and the clamp body are connected by a spring.

  Accordingly, an object of the present invention is to provide a joining device that can clamp a workpiece with a predetermined clamping force even when the state of the workpiece varies.

The present invention provides a support for supporting an object to be joined including a plurality of joining members;
A clamp body which is provided so as to be displaceable in a reference direction close to and away from the support body, and which clamps an object to be joined in cooperation with the support body;
A clamp driving means for driving the clamp body to move in a reference direction close to and away from the support; and
A processing means for bonding each bonding member of the object to be bonded sandwiched between the support and the clamp body under a set processing condition;
A pressing force detecting means for detecting the pressing force of the object to be joined by the clamp body;
And a control unit that controls the clamp driving unit so that the pressing force of the object to be joined by the clamp body becomes a predetermined value based on the detected pressing force.

  According to the present invention, the object to be joined is clamped by the clamp body and the support body, and the clamped object is joined by the processing means. The control means moves the clamp body based on the pressing force of the object to be joined by the clamp body. As a result, even if the state of the object to be bonded varies for each bonding, the object to be bonded can be pressed with a predetermined pressing force. Therefore, it is possible to prevent the object to be bonded from being shaken due to a small clamping force, and to prevent the object from being deformed due to a large clamping force, thereby improving the bonding quality. Moreover, the contact confirmation operation | work with a clamp body and a to-be-joined object can be performed, without giving big pressing force to a to-be-joined object.

  Further, for example, the joining apparatus further includes a processing state acquisition unit that acquires a joining processing state by the processing unit, and the control unit follows the joining processing state, and the pressing force of the object to be joined by the clamp body corresponds to the joining processing state. The clamp driving means may be controlled so as to obtain a value. Accordingly, the clamp driving means can be adjusted in accordance with the joining processing state that changes with time, and the object to be joined can be held with an appropriate holding force obtained by experiments.

The present invention further includes a measuring means for measuring the dimensions of the object to be joined,
The control means sets processing conditions for the processing means based on the measurement result.

  According to the present invention, the processing conditions by the processing means are set based on the acquired dimensions of the workpiece. And each joining member is joined on the set joining conditions. The bonding quality can be further improved by performing the bonding under appropriate bonding conditions according to the dimensional variation of the objects to be bonded.

  For example, when the joining device is a striking device, it is possible to adjust the push-in amount for immersing the rivet into the workpiece based on the thickness of the workpiece. As a result, the exposed surface of the punch rivet and the surface of the object to be joined can be flush with each other, and the aesthetic appearance can be improved.

According to the present invention, the measuring means includes a clamp body reference position, which is a position in the reference direction of the clamp body when the clamp body is in contact with the support body with no pressing force or a small pressing force, and a clamp with a predetermined reference pressing force. A storage unit that stores a support displacement amount that is a displacement amount in a reference direction of the support when the body presses the support;
A detection unit for detecting a clamp body pressing position, which is a position in the reference direction of the clamp body when the clamp body presses the object to be joined with the reference pressing force;
Based on the clamp body reference position, the support body displacement amount, and the clamp body pressing position, the distance from the support body to the clamp body when the clamp body presses the work piece with the reference pressing force is the dimension of the work piece. And an arithmetic unit for calculating as follows.

  According to the present invention, after storing the clamp body reference position and the support body displacement amount, the clamp body pressing position is detected. And a measurement means calculates | requires the distance between a clamp body and a support body from the support pair displacement amount with respect to a clamp body reference position, and a clamp body press position. Since the object to be bonded is sandwiched between the clamp body and the support body, the dimension of the object to be bonded can be calculated by calculating the distance between the clamp body and the support body.

The present invention further includes a support state detecting means for detecting a support state of the object to be joined by the support,
The control means controls the processing means based on the support state of the object to be joined by the support body so as to allow the joining process when the pressing force of the object to be joined by the clamp body is equal to or higher than a predetermined reference pressing force. It is characterized by.

  According to the present invention, the support state detection means detects whether or not the support supports the object to be joined. The pressing force applied from the clamp body is detected by the pressing force detection means. When the workpiece is supported by the support and the pressing force applied to the workpiece by the clamp body is equal to or greater than the reference pressing force, the workpiece is sandwiched between the support and the clamp body.

  Based on the support state detection means and the pressing force detection means, the control means determines that it is in the clamping state and allows the joining process. As a result, even if there are positional variations, dimensional variations of the objects to be joined, and gaps between the respective joining members, the joining process can be performed in a state where the objects to be joined are securely clamped, and the joining quality is improved. be able to. Furthermore, it is not necessary to accurately teach in advance the amount of movement that the support and the clamp body move to clamp the object to be joined, and the clamping work can be shortened.

The present invention also includes a base on which a support is provided;
A base driving means for displacing the base;
A deformation state detection means for detecting the deformation state of the base,
The control means controls the base drive means based on the deformation state of the base.

  When the support is pressed by at least one of the clamp body and the processing means, the base is deformed. According to the present invention, the control means controls the base drive means based on the detected deformation state of the base. Even if the base is deformed, the control means displaces the base so as to compensate for the amount of deformation. Accordingly, the position of the object to be bonded can be kept the same before and after the base deformation, and the object to be bonded can be prevented from being deformed together with the support.

The present invention also includes a base on which a support, a clamp body, a clamp driving means, and a processing means are provided.
Further includes base drive means for driving the base to displace,
The control means controls the base driving means and the clamp driving means so as to drive the clamp body while displacing the base.

  According to the present invention, the control means drives the displacement of the base and drives the displacement of the clamp body. As a result, the clamp body can be moved to the joining position in a shorter time than when only the base is moved to move the clamp body to the joining position.

In the present invention, the processing means includes
A holding part for holding the joining piece detachably;
And holding unit driving means for driving the holding unit to move in a reference direction approaching and separating from the workpiece.

  According to the present invention, the holding portion holding the joining piece is moved toward the support, and the joining piece is immersed in the article to be joined. Each joining member is physically coupled by the joining piece being immersed in the article to be joined. Such a processing means immerses the joining piece in the article to be joined, and therefore, it is necessary to apply a larger load to the article to be joined as compared with joining processing such as resistance spot joining. Therefore, it is important to set the clamping force for clamping the workpieces to an appropriate value. According to the present invention, with the above-described configuration, an optimum clamping force can be applied to the workpiece regardless of the state of the workpiece, and the bonding quality can be improved. Further, by independently driving the clamp body and the holding portion, the holding portion can be moved with high accuracy, and the joining quality can be further improved.

  As described above, according to the first aspect of the present invention, even when the objects to be joined vary, the teaching force applied to the objects to be joined can be maintained at a predetermined value. Thereby, the joining quality of each joining member to be joined can be improved regardless of the state of the object to be joined. In addition, since the pressing force of the clamp body can be adjusted, the clamping force may be changed for each workpiece, or the clamping force may be changed according to the bonding processing state. By sandwiching the workpiece with an appropriate clamping force for each processing state for each workpiece, deformation and displacement of the workpiece can be prevented, and the bonding quality can be improved.

  According to the second aspect of the present invention, the processing conditions by the processing means are set based on the acquired dimensions of the object to be joined, and the respective joining members are joined under the set joining conditions. Thus, joining quality can be further improved by joining on a suitable joining condition for every dimension of a to-be-joined object.

  For example, when the joining device is configured to include a striking device, it is possible to adjust the push-in amount for immersing the punch rivet into the article to be joined based on the thickness of the joining member to be joined. As a result, the exposed surface of the punch rivet and the surface of the object to be joined can be flush with each other, and the aesthetic appearance can be improved.

  According to the third aspect of the present invention, the dimension of the object to be joined can be calculated by calculating the distance between the clamp body and the support body. In this case, the dimensions of the workpiece can be measured in a state where the clamp body presses the workpiece with a predetermined reference pressure, so even if there is a gap in each joining member, the gap is eliminated. The plate thickness of the object to be bonded can be measured, and the plate thickness can be measured with high accuracy. Further, by calculating the distance between the clamp body and the support body based on the displacement amount of the support body, even if the support body is displaced due to the deflection due to the reference pressing force, the deflection is corrected and the more accurate. The thickness of the object to be joined can be measured.

  According to the fourth aspect of the present invention, the joining process is performed after determining that the object is sandwiched. As a result, the joining process can be prevented from being performed in a non-clamping state, and the joining quality can be kept constant. Further, it is not necessary to accurately teach in advance the amount of movement of the support body and the sandwiching body, and the time required for the teaching work can be shortened.

  Further, according to the present invention, it is possible to prevent the object to be clamped from being deformed together with the support body by controlling the base driving means based on the detected deformation state of the base. Can do. Thus, joint quality can be further improved by preventing deformation of the objects to be joined.

  According to the sixth aspect of the present invention, the control means drives the displacement of the base and also drives the clamp body to move. As a result, the clamp body can be moved to the joining position in a shorter time than when only the base is moved to move the clamp body to the joining position.

  According to the seventh aspect of the present invention, since the processing means immerses the joining piece in the object to be joined, it is necessary to apply a larger load to the object to be joined than other processing means. According to the present invention, the object to be joined can be clamped without being deformed by driving the clamp body to be displaced independently of the processing means. Thereby, even when the processing means applies a large load to the workpiece, the bonding quality can be improved.

  FIG. 1 is a simplified cross-sectional view showing a striking device 40 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a part of the striking device 40 in order to explain the method of joining the joining members 2 and 3 with the punch rivet 1. FIG. 3 is an enlarged perspective view showing a plurality of punch rivets 1. The striking device 40 is included in the configuration of the joining device that joins the joining members 2 and 3 using the punch rivet 1.

  The punch rivet 1 (hereinafter simply referred to as the rivet 1) serves as a joining piece for joining the joining members 2 and 3 together. As shown in FIG. 3, the rivet 1 is formed in a bottomed short cylinder shape, and an opening 8 is formed on one side in the axial direction. The rivet 1 has a shaft portion 4 and a head portion 5. The shaft portion 4 is formed in a short cylindrical shape. The head 5 is connected to one end 6 in the axial direction of the shaft 4. The head portion 5 is formed in a substantially dish shape and closes the other opening in the axial direction of the shaft portion 4. Further, the head 5 has a protruding portion 5 a that protrudes outward in the radial direction perpendicular to the axial direction from the outer peripheral portion of the shaft portion 4 to the entire circumference in the circumferential direction.

  As shown in FIG. 2 (1), the joining method of the joining members 2 and 3 by the rivet 1 is to prepare a plurality of, for example, two joining members 2 and 3 to be joined. Next, the joining members 2 and 3 are sandwiched by the die 50 and the clamp shaft 53 in a state of being overlapped. Specifically, the striking device 40 brings the die 50 into contact with the die-side surface 9a on the one side A1 side of the workpiece 9 in the parallel direction. Further, the clamp shaft 53 is brought into contact with the punch side surface 9b which is the other side A2 side of the workpiece 9 in the parallel direction. Next, the free end portion 7 of the shaft portion 4 on the opposite side to the head portion 5 of the rivet 1 is brought into contact with the joint portion of the article 9 to be joined.

  As shown in FIG. 2 (2), the punch 51 presses the head 5 of the rivet 1 to immerse the rivet 1 into the workpiece 9. The rivet 1 is immersed in the workpiece 9. The immersed rivet 1 is caulked by being deformed inside the article 9 and is prevented from coming out of the article 9. As the rivet 1 bites into the workpiece 9 in this way, the respective joining members 2 and 3 are physically joined.

  In addition, the structure comprised including each joining member 2 and 3 is called the to-be-joined object 9. FIG. Of the two bonding members 2 and 3 to be bonded, the bonding member 2 that is on the punch side in bonding is referred to as a punch-side bonding member 2, and the bonding member 3 that is on the die side in bonding is referred to as a die-side bonding member 3. A direction in which the joining members 2 and 3 are arranged is referred to as a parallel direction A.

  The striking device 40 is used for spot bonding in which the bonding members 2 and 3 are locally bonded. Each of the plurality of joining members 2 and 3 is, for example, an aluminum alloy thin plate material that is press-formed. Further, for example, the joining with the rivet 1 is used for manufacturing a body of a household electric appliance such as a washing machine or an air conditioner and a body of an automobile. Further, the joining by the rivet 1 may be used for joining and assembling the residential structural truss.

  As shown in FIG. 1, the striking device 40 is set with a predetermined reference axis L1. The reference axis L1 is an axis that serves as a reference for the striking device 40, and is fixed to the striking device 40. When the striking device 40 performs the joining operation, the reference axis L1 extends along the parallel direction A of the joining members 2 and 3 to be joined. A direction extending along the reference axis L1 is referred to as a reference direction Z.

  The striking device 40 is configured to include a punch structure 41, a punch driving means 42, a die structure 43, and a base 45. The punch structure 41 is provided so as to detachably hold the rivet 1 and move along the reference axis L1. The punch driving means 42 drives the punch structure 41 to be displaced along the reference axis L1. The punch structure 41 and the die structure 43 are arranged along the reference axis L1 and provided at positions facing each other. The die structure 43 supports the workpiece 9 from the opposite side to the punch structure 41.

  The base 45 is formed in a substantially C shape. The base 45 is connected to the tip of the robot arm 44 and is configured to be movable in three directions orthogonal to each other. In the base 45, the punch structure 41 and the punch driving means 42 are connected to one end 47 in the circumferential direction, and the die structure 43 is connected to the other end 48 in the circumferential direction.

  The punch structure 41 holds the rivet 1 in a detachable manner. The axis of the rivet 1 to be held is coaxial with the reference axis L1. The punch structure 41 is provided so as to be displaceable in the reference direction Z with respect to the die structure 43. The punch structure 41 includes a main body portion 56, a motor housing portion 57, a punch shaft 52, a clamp shaft 53, a rotation transmission member 54, a clamping servomotor 55, load cells 80 a and 80 b, and a rotation prevention member 99. It is comprised including.

  The punch shaft 52 is formed in a cylindrical shape and is arranged coaxially with the reference axis Z. A punch 51 is formed at one axial end of the punch shaft 52. The punch 51 is a portion that contacts the rivet 1 and presses the rivet 1 against the workpiece 9. The punch 51 constitutes a part of processing means for joining the joining members 2 and 3. The clamp shaft 53 is provided so as to be displaceable in the reference direction Z with respect to the punch shaft 52. The clamp shaft 53 serves as a clamp body that presses the workpiece 9. The clamp shaft 53 is formed in a cylindrical shape and is disposed coaxially with the reference axis Z. The punch shaft 52 is accommodated in the internal space of the clamp shaft 53. The servo motor 55 for clamping serves as a clamp driving unit that drives the clamp shaft 53 to move in the reference direction Z.

  FIG. 4 is an enlarged cross-sectional view showing the punch structure 41. The main body 56 is supported by the circumferential one end 47 of the base 45 so as to be displaceable in the reference direction Z. The motor housing portion 57 is integrally connected to the main body portion 56 and protrudes from the main body portion 56 toward the die structure 43. In the motor housing portion 57, an internal space 200 having an opening coaxial with the reference axis L1 is formed.

  The clamping servomotor 55 is accommodated in the internal space 200 of the motor accommodating portion 57. The clamping servo motor 55 is realized by a hollow servo motor formed in a ring shape. The clamping servomotor 55 is fixed to the motor housing portion 57 in a state where the opening is disposed coaxially with the reference axis L1. In the present embodiment, the clamping servomotor 55 is fixed to the motor housing portion 57 via the clamping load cell 80a. The clamping load cell 80a is formed in a ring shape. The opening of the clamp load cell 80a is formed coaxially with the reference axis L1. The clamping load cell 80a is formed with a connecting portion that goes around the reference axis L1, and the clamping servomotor 55 and the motor housing portion 57 are connected by this connecting portion.

  The clamp shaft 53 and the punch shaft 52 are inserted into the internal space of the servo motor 55 for clamping. The rotation transmission member 54 is formed in a cylindrical shape. In the present invention, the ring shape and the cylindrical shape refer to shapes in which openings are formed at both ends in the axial direction, and an internal space that is inserted in the axial direction is formed. The rotation transmitting member 54 is fixed to the clamping servo motor 55 in a state of being arranged coaxially with the reference axis L1.

  The clamp shaft 53 is disposed in the internal space of the rotation transmitting member 54 in a state of being disposed coaxially with the reference axis L1. The clamp shaft 53 can protrude from the motor housing portion 57 toward the die structure 43.

  The punch shaft 52 is disposed in the internal space of the clamp shaft 53 in a state of being disposed coaxially with the reference axis L1. The punch shaft 52 is integrally fixed to the main body 56 via a punch load cell 80b. The punch shaft 52 can project from the motor housing portion 57 toward the die structure 54 through the opening of the motor housing portion 57 from the internal space of the motor housing portion 57.

  As described above, the punch shaft 52 and the clamp shaft 53 are disposed in the internal space of the motor housing portion 57 and are inserted through the opening of the clamping servo motor 55 and through the opening of the clamp load cell 80a. Extend outside.

  The clamp shaft 53 is formed to be movable in the reference direction Z with respect to the punch shaft 52. A screw groove in a ball screw is formed on the outer peripheral portion 201 of the clamp shaft 53 on the axial direction main body portion side. Further, a spline groove extending along the axial direction Z is formed on the outer peripheral portion 202 of the clamp shaft 53 on the axial die structure side.

  The clamping servomotor 55 includes a rotor side ring and a stator side ring, and rotationally drives the rotor side ring relative to the stator side ring about the axis. In the servo motor 55 for clamping, the rotor side ring is fixed to the rotation transmitting member 54, and the stator side ring is fixed to the motor housing portion 57. The rotation transmitting member 54 transmits the rotational force output from the clamping servo motor 55 to the clamp shaft 53. The rotation transmission member 54 serves as a nut portion in a so-called ball screw. The rotation transmitting member 54 is formed to be rotatable around the reference axis L <b> 1, and is screwed into a screw groove formed in the axial direction main body side outer peripheral portion 201 of the clamp shaft 53. The clamp shaft 53 is supported in the reference direction Z by screwing the clamp shaft 53 into the rotation transmitting member 54.

  A rotation preventing member 99 is fixed to the motor housing portion 57. The rotation preventing member 99 allows the clamp shaft 53 to move in the reference direction Z and prevents it from rotating around the reference axis L1. The rotation preventing member 99 is disposed closer to the die structure 43 than the clamping servomotor 55. The rotation blocking member 99 has an opening that is coaxial with the reference axis L1, and the clamp shaft 53 and the punch shaft 52 are inserted through the opening. The rotation preventing member 99 is formed with a protruding piece that fits into the spline groove of the outer peripheral portion 202 on the axial die structure side of the clamp shaft 53. For example, the rotation preventing member 99 is realized by a ball spline bush.

  When the clamping servomotor 55 is driven, the rotation transmitting member 54 rotates around the reference axis L1 together with the rotor side ring. The rotation transmission member 57 transmits power to the clamp shaft 53. Since the clamp shaft 53 is prevented from rotating around the reference axis L1 by the rotation preventing member 99, the clamp shaft 53 moves in the reference direction Z when power is supplied from the rotation transmitting member 57. In other words, since the clamp shaft 53 and the rotation transmission member 54 constitute a ball screw mechanism, when the rotation transmission member 54 is rotationally driven in a state in which the rotation of the clamp shaft 53 is prevented, the clamp shaft 53 is rotated by the rotation transmission member. 54 moves in the reference direction Z direction.

  As shown in FIG. 1, the base 45 is provided with a guide groove 58 for guiding the main body portion 56 of the punch structure 41 in the reference direction Z. The guide groove 58 is formed in the other circumferential end 47 of the base 45. The main body 56 of the punch structure 41 is provided with a fitting portion 59 that fits into the guide groove 58 of the base 45. By fitting the fitting portion 59 in the guide groove 58, the main body portion 56 of the punch structure 41 is prevented from being displaced in directions other than the reference direction Z. The guide groove 58 is realized by, for example, a rail, and the fitting portion 59 is realized by a slider.

  The punch drive means 42 includes a punch servomotor 60, a rotation transmission mechanism 62, a screw shaft 63, and a speed reducer 64. The punch servomotor 60 is supported by the base 45 and rotates its output shaft 60a. The screw shaft 63 extends coaxially with the reference axis L1 and is supported by the base 45, and is provided to be rotatable around the reference axis L1. The rotation transmission mechanism 62 applies rotation of the output shaft 60 a to the speed reducer 64 by the belt 61, and the speed reducer 64 reduces the rotational force of the output shaft 60 a and applies it to the screw shaft 63.

  The main body portion 56 of the punch structure 41 is provided with a threaded portion 65 that is threadedly engaged with the screw shaft 63. When the rotational force is applied and the screw shaft 63 rotates, the punch structure 41 screwed into the screw shaft 63 can be moved in the reference direction Z.

  As a moving means for moving the clamp shaft 53, an air cylinder or a hydraulic cylinder can be used in addition to the servo motor. However, when an air cylinder is used, the operation speed and response speed are slower than those of the servo motor. This makes it difficult to operate in conjunction with the punch shaft 53 displaced by the punch servomotor 60. In addition, when using an air cylinder and a hydraulic cylinder, the clamp shaft 53 is formed in a cylindrical shape, so special measures such as the use of a hollow cylinder and the arrangement of small cylinders around the reference axis L1 are necessary. .

  On the other hand, by using a hollow servomotor to move the clamp shaft 53, the operation speed and response speed of the clamp shaft 53 can be improved, and the interlocking operation with the punch shaft 53 can be easily performed. . Further, the workpiece 9 can be uniformly pressurized by the clamp shaft 53 without performing any special processing as compared with the cylinder and without causing a single contact.

  Further, when a cylindrical electric motor is employed as the moving means for moving the clamp shaft 53, the arrangement position of the electric motor is shifted from the reference axis L1 like the punch servomotor 60. In this case, the apparatus becomes large and complicated.

  On the other hand, by adopting a hollow servo motor as the moving means for moving the clamp shaft 53, the central axis of the motor and the reference axis L1 can be matched. As a result, the rotation transmitting member 54 can be directly driven to rotate, thereby reducing the number of components and saving space.

  The central axis of the clamping servomotor 55 and the rotation transmitting member 54 is provided coaxially with the reference axis L1. When the clamp shaft 53 pressurizes the workpiece 9, a reaction force from the workpiece 9 is applied to the rotation transmission member 54 via the clamp shaft 53. The rotation transmitting member 54 transmits the reaction force in the reference direction Z and applies it to the clamping servo motor 55. As a result, even if a reaction force is applied from the workpiece 9 to the rotation transmission shaft 54 and the clamp shaft 53, the rotation transmission shaft 54 and the clamp shaft 53 can receive the reaction force stably without receiving any force other than the reference direction Z. The rotation transmission member 54 can be smoothly rotated by the servo motor 55.

  The punch shaft 52 is displaced in the reference direction one Z1 by the punch servomotor 60 at a predetermined speed, and the clamp shaft 53 is displaced in the other reference direction Z2 by the clamp servomotor 55 by the predetermined speed. The clamp shaft 53 can be arranged at a constant position in the reference direction Z regardless of the movement of If it does in this way, the area | region where the clamp axis | shaft 53 and the rotation transmission member 54 screw together can be increased as the punch axis | shaft 52 goes to the die | dye structure 43. FIG. As a result, when the rivet 1 is immersed, the coupling strength between the clamp shaft 53 and the rotation transmitting member 54 can be improved, and the clamp shaft 53 can be prevented from shaking.

  During the caulking operation, the clamping servo motor 55 is controlled to have a predetermined rotational torque so that the pressing force of the clamp shaft 53 becomes the specified pressing force. For example, when the punch component 41 is moved along the reference direction Z in a state where the workpiece 9 is clamped by the clamp shaft 53 and the die 50, the pressing force applied to the workpiece 9 by the clamp shaft 53 increases. In this case, the clamping servo motor 55 rotates in the reverse direction and displaces the clamp shaft 52 in the direction of detachment from the workpiece 9, thereby reducing the pressing force applied to the workpiece 9 by the clamp shaft 52. By doing so, the pressing force applied to the workpiece 9 by the clamp shaft 52 and the position of the clamp shaft 52 relative to the workpiece 9 can be kept constant regardless of the movement of the punch structure 41.

  The striking device 40 has a load detection means for detecting a load. For example, the load detection means is realized by the load cells 80a, 80b, 80c or the strain gauge 80d as described above. The striking device 40 includes a clamp load cell 80a, a punch load cell 80b, and a die load cell 80c. The clamp load cell 80a detects a pressing force applied to the workpiece 9 by the clamp shaft 53. In the present embodiment, the clamping load cell 80 a connects the clamping servo motor 55 and the motor housing portion 57 and is fixed to the motor housing portion 57.

  The punch load cell 80 b detects the pressing force applied to the workpiece 9 by the punch shaft 52. In the present embodiment, the punch load cell 80 b connects the punch shaft 52 and the main body 56 and is fixed to the main body 56.

  The die load cell 80 c detects the pressing force that the clamp shaft 53 and the punch shaft 52 apply to the die structure 43. In other words, the die load cell 80c detects the pressing force obtained by adding the pressing force to the workpiece 9 by the clamp shaft 53 and the punch shaft 52. The die load cell 80 c is provided in the die structure 43. In the present embodiment, the die load cell 80 c is fixed to a die support member 69 that supports the die 50.

  In order to further detect the pressing force applied to the die structure 43, a die strain gauge 80d may be provided on the die structure 43 side of the base 45. The strain gauge detects the amount of strain of the base 45. When the die structure 43 is pressed, the pressing force applied to the die structure 43 can be calculated by detecting the strain amount from the strain gauge.

  In this way, by measuring the pressing force by each of the load cells 80a, 80b, 80c and the strain gauge 80d, the pressing force applied to the workpiece 9 by the punch shaft 52 and the clamp shaft 53 can be accurately detected. Each of the load cells 80a, 80b, 80c and the strain gauge 80d gives information indicating the detected pressing force to the control means 73 described later.

  FIG. 5 is a perspective view showing the clamp load cell 80a. FIG. 6 is a cross-sectional view showing a clamp load cell 80a. As described above, the clamp load cell 80a is formed in a ring shape coaxial with the reference axis L1. The punch shaft 52 and the clamp shaft 53 are inserted through openings formed in the clamp load cell 80a.

  In the clamp load cell 80a, a motor connecting portion 98 for fixing the clamp servomotor 55 is formed around the reference axis L1. The clamping servomotor 55 is formed with a flange portion 95 projecting radially outward over the entire circumference in one end portion in the axial direction. The flange portion 95 and the motor connecting portion 98 are connected by a screw member.

  At the time of clamping, the clamping servomotor 55 is given a reaction force F <b> 1 from the workpiece 9 via the clamp shaft 53 and the rotation transmission member 54. At this time, the clamping servomotor 55 pulls the motor connecting portion 98 in the reference direction Z by the flange portion 95. The motor connecting portion 98 is given a tensile force F2 that goes around the reference axis L1 and is uniform in the circumferential direction. Thus, the clamping load cell 80a can accurately detect the pressing force applied from the clamping servomotor 55.

  FIG. 7 is a perspective view showing a punch load cell 80b. FIG. 8 is a sectional view showing a punch load cell 80b. The punch load cell 80b is formed in a ring shape coaxial with the reference axis L1. The punch load cell 80b has an inner thread formed on the inner periphery. An external thread is formed at one end 97 in the axial direction of the punch shaft 52. One end 97 in the axial direction of the punch shaft 52 is screwed into the inner thread portion of the punch load cell 80b, so that the punch shaft 52 and the punch load cell 80b are detachably fixed. The punch load cell 80 b is fixed to the main body 56 directly or indirectly at the end surface opposite to the punch shaft 52. The punch load cell 80 b is fixed to the main body 56 by a screw member 94.

  At the time of punching, the punch shaft 52 is given a reaction force F3 from the workpiece 9. At this time, the punch shaft 52 presses the punch load cell 80b in the reference direction Z. Since the punch load cell 80b is formed coaxially with the punch shaft 52, the pressing force applied from the punch shaft 52 can be accurately detected. As the punch load cell 80b, for example, a tension / compression load cell is used.

  A rivet holding means for holding the rivet 1 is provided at the tip of the punch shaft 52. The rivet holding means can suck and release air. The rivet holding means sucks air in the filling space 67 serving as the inner peripheral space of the clamp shaft 53 through a suction hole formed in the punch 51. By sucking the air in the filling space 67, the rivet 1 disposed in the filling space 67 is sucked and held by the punch 51.

  A filling hole (not shown) that connects the filling space 67 and the outer peripheral space 68 is formed in the outer peripheral portion of the clamp shaft 53. The filling hole is a hole for filling the rivet 1 from the outer peripheral space 68 to the filling space 67. The rivet 1 is transported by a rivet filling device and filled into the filling space 67 through the filling hole. The rivet 1 filled in the filling space 67 is attracted and held by the punch 51.

  FIG. 9 is an enlarged perspective view showing the die structure 43. FIG. 10 is a plan view showing the die structure 43. The die structure 43 includes a die support member 69 and a die 50. The die support member 69 supports the die 50 and is connected to one circumferential end 48 of the base 45. The die 50 is fixed to the free end portion of the die support member 69.

  The die 50 serves as a support that supports the workpiece 9. The die 50 is formed in a substantially cylindrical shape, and is formed coaxially with the reference axis L1. The die 50 is formed with a contact portion 81 that faces the punch structure 41. The contact portion 81 is formed in a ring shape centered on the reference axis L1. The contact portion 81 has a contact surface 83 that is perpendicular to the reference axis L1. In addition, the die 50 is formed with an immersion portion 82 that is immersed from the contact portion 81. The immersion part 82 is provided radially inward of the contact part 81. Further, the die 50 is formed with a conical protrusion 50 a that protrudes from the immersion portion 82 toward the punch structure 41. The protrusion 50a is provided coaxially with the reference axis L1.

  Thus, by forming the immersion part 82 and the protrusion part 50a, the rivet 1 pushed into the article 9 can be deformed into a predetermined shape. In a state where the workpiece 9 is sandwiched, the contact surface 83 and the workpiece 9 are in surface contact.

  The die structure 43 is provided with a contact state detection sensor 84 that detects a contact state between the die 50 and the workpiece 9. The contact state detection sensor 84 is provided so as to be able to detect a relative position and a relative posture between the workpiece 9 and the die 50 held in advance. For example, the contact state detection sensor 84 is realized by at least three displacement sensors 84a, 84b, and 84c. The displacement sensors 84a, 84b, 84c are provided on the die 50 at different positions. Each displacement sensor 84a, 48b, 84c can detect the relative displacement and relative posture between the die 50 and the workpiece 9 by detecting the amount of displacement of the workpiece 9 with respect to each other. In addition, it is possible to detect whether or not the contact surface 83 of the die 50 is in contact with the die side surface 9a of the article 9 to be bonded.

  Each displacement sensor 84 a, 84 b, 84 c measures the distance from the three or more measurement parts to the workpiece 9 in the contact part 81 of the die 50. Each measurement part is arranged so that a two-dimensional region having a straight line connecting three or more measurement parts as edges is formed. For example, three measurement parts are provided 120 degrees apart in the circumferential direction of the die 50 and are provided as far as possible on the radially outer side of the contact part 81. As a result, the measurement accuracy can be improved.

  Each displacement sensor 84a, 84b, 84c is realized by, for example, a contact displacement sensor. The contact-type displacement sensor includes a contact pin that is provided so as to be movable in the reference direction Z from the contact surface 83, and a detection unit that detects the amount of movement of the pin. The contact pin is given a spring force in a direction protruding from the contact surface 83 in the axial direction Z. When the die 50 is brought closer to the workpiece 9, each pin comes into contact with the workpiece and is displaced in the reference direction Z. In a state where each contact pin is in contact with the die side surface 9a of the article 9 to be bonded, the displacement amount of each contact pin is given, and the relative distance from the center position of the die 50 to the article 9 to be bonded, and the die 50 The relative posture between the contact surface 83 and the die side surface 9a of the workpiece 9 can be obtained. By using the spring-type contact displacement sensors 84a, 84b, and 84c in this way, the contact state detection sensor 84 can be reduced in size. Moreover, such a displacement sensor is an example of implementation, and other displacement sensors may be used. For example, a contact state detection sensor can also be realized using a non-contact displacement sensor such as a laser distance sensor.

  FIG. 11 is a perspective view showing the rivet filling device 78. The rivet filling device 78 includes an alignment holding unit 90, a rivet standby unit 91, a transport path forming unit 92, and a power supply unit 93. The alignment holding unit 90 aligns and holds a plurality of rivets 1. The rivets 1 held in the alignment holding unit 90 move to the rivet standby unit 91 one by one. The power supply unit 93 applies power to the rivet 1 of the rivet standby unit 91 so as to pass through the transport path forming unit 92 and move to the striking device 40. Since the conveyance path forming unit 92 is made of a flexible material, the rivet 1 can be supplied to the striking device 40 even when the base 45 is moving. Such a rivet filling device 78 is an example of implementation and may have other configurations.

  FIG. 12 is a side view showing the joining equipment 100 including the striking device 40. The joining facility 100 includes a joining device 101, a rivet filling device 78, a holding device 102, and a safety fence 104. In the present embodiment, the joining device 101 includes the above-described striking device 40 and the articulated robot 103 that moves and moves the striking device 40.

  The articulated robot 103 has a robot arm 77 that can move in three directions orthogonal to each other, and a base 45 of the striking device 40 is connected to the tip of the robot arm 77. When the robot arm 77 is driven to be displaced by the robot arm driving means, the base 45 can be displaced to a predetermined joining position. The articulated robot 103 serves as a base drive means for driving the base 45 of the striking device 40 to be displaced.

  The holding device 102 holds the workpiece 9 when the bonding members 2 and 3 are bonded. The rivet filling device 78 supplies rivets to the striking device 40. When the rivet 1 is supplied and displaced to the joining position, the striking device 40 immerses the rivet into the joining position of the article 9 to join the joining members 2 and 3.

  The safety fence 104 is provided to prevent an operator from entering the movable range of the joining apparatus 101. The safety fence 104 has an intrusion prevention sensor. The intrusion prevention sensor issues a warning and gives an operation stop command to the joining apparatus 101 when an operator enters the operable range of the articulated robot 103.

  FIG. 13 is a block diagram showing an electrical configuration of the striking device 40. As described above, the striking device 40 includes the punch servomotor 60, the clamp servomotor 55, the load cells 80a, 80b, and 80c, the contact state detection sensor 84, the rivet holding means 74, and the control means 73. including.

  Each servo motor 55, 60 and robot arm driving means 77 is provided with an encoder. Each encoder gives an encoder value indicating the angular displacement amount of each output shaft of the servo motor 66 and the robot arm driving means 77 to the control means 73. The control means 73 can determine the positions of the base 45, the clamp shaft 53, and the punch shaft 52 based on information given from the encoder.

  The control means 73 further controls the punch servomotor 60, the clamp servomotor 55 and the rivet holding means 74 based on information given from the load cell 80 and the contact state detection sensor 84.

  The servo motors 55 and 60 control the motor current so as to rotate at a predetermined rotational speed, detect the motor current, and provide it to the control means 73. The motor current is proportional to the amount of torque required to rotate at a predetermined rotational speed. The control means 73 can determine the pressing force applied to the clamp shaft 53, the punch shaft 52, and the die structure 43 based on the motor current. The control means 73 may calculate the pressing force from the motor current instead of each load cell 80a, 80b, 80c.

  Moreover, the control means 73 of this Embodiment controls the joining equipment 100. FIG. In this case, the control means 73 further controls the robot arm driving means 77 that drives the robot arm 44 to move and the rivet filling device 78.

The control means 73 includes a calculation unit 75 that executes a predetermined control program, and a program storage unit 76 that stores the control program. The calculation unit 75 is a CPU (Central
Realized by Processing Unit). The program storage unit 76 is a ROM (Read
(Only Memory). The control means 73 performs a joining operation by executing a control program stored in the program storage section 76, and each servo motor 55, 60, rivet holding means 74, robot arm driving means 77, and rivet filling device 78 are respectively connected. Control.

  FIG. 14 is a flowchart showing a procedure of main joining operations of the joining apparatus 101. First, in step a0, when the preparation related to the bonding operation is completed, the process proceeds to step a1, and the control means 73 starts the bonding operation.

  In step a1, the control means 73 gives rivet filling command information to the rivet filling device 78. The rivet filling device 78 given the rivet filling command information supplies the rivet 1 to the filling space 67. The control unit 73 operates the rivet holding unit 74 to hold the rivet 1 on the punch 51. When the control means 73 holds the rivet 1 on the punch 51, the control means 73 proceeds to step a2.

  In step a <b> 2, the control unit 73 controls the robot arm driving unit 77 and the servo motor 55 for clamping, and sandwiches the workpiece 9 between the die 50 and the clamp shaft 53. When the clamping of the workpiece 9 is completed, the process proceeds to step a3.

  In step a3, the control means 73 controls the punch servomotor 60. The rivet 1 is brought into contact with the workpiece 9 by the punch 51, and the rivet 1 is further immersed in the workpiece 9. The joining members 2 and 3 are physically joined by the rivet 1 being deformed and immersed in the article 9 to be joined. When the rivet 1 is immersed in the workpiece 9 in this way, the process proceeds to step a4, and the control means 73 ends the joining operation in step a4.

  FIG. 15 is a flowchart showing the procedure of the die contact operation of the joining apparatus 101. FIG. 16 is a side view for explaining the procedure of the die contact operation of the joining apparatus 101. The bonding apparatus 101 performs a die contact operation before pressing the workpiece 9 by the clamp member 53 in step a2 of the bonding operation described above. Specifically, the control means 73 controls the robot arm driving means 77 to move the base 45 to bring the die 50 into surface contact with the workpiece 9.

  First, in step b0, when the preparation for the die contact operation is completed, the process proceeds to step b1, and the control means 73 starts the die contact operation. In step b1, the control means 73 controls the robot arm drive means 77 to move the die 50 to a predetermined standby position as shown in FIG. The standby position is a position where the arrangement position of the die 50 is closer to the one side A1 in the parallel direction of the article 9 to be joined than the assumed joining position taught in advance. If the control means 73 moves the base 45 so that the die | dye 50 may come to a standby position, it will progress to step b2.

  In step b <b> 2, the control unit 73 moves the base 45 in the reference direction Z so that the die 50 comes close to the workpiece 9. In step b2, it is preferable to move the base 45 at a speed lower than that in step b1. As a result, the article 9, the die 50, and each displacement sensor 84 can be prevented from being damaged.

  The control means 73 moves the base 45 and brings the contact pins of each displacement sensor 84 into contact with the workpiece 9 as shown in FIG. Thus, when each displacement sensor 84 becomes a state which can measure the relative distance of the die | dye 50 and the to-be-joined object 9, it progresses to step b3.

  In step b3, each displacement sensor 84 gives the detection result to the control means 73. The control means 73 acquires the relative distances D1, D2, D3 between the position where each displacement sensor 84 is provided and the workpiece 9 and proceeds to step b4.

  In step b4, the control means 73 determines the target position and target of the base 45 such that the contact surface 83 of the die 50 comes into surface contact with the workpiece 9 based on the acquired relative distances D1, D2, and D3. Calculate posture. When the die side surface 9a is a plane perpendicular to the parallel direction A, a target position and a target posture for moving the base 45 are expressed by a movement amount calculation formula described later.

  When the control means 73 substitutes the relative distances D1, D2, and D3 into the predetermined movement amount calculation formula to determine the target position and the target posture to move the base 45, the process proceeds to step b5.

  In step b5, the control means 73 moves the base 45 so as to be in the target posture as shown in FIG. 16 (3). When the base 45 is moved to the target posture, the parallel direction A of the workpiece 9 and the reference direction Z coincide. That is, the die side surface 9a of the workpiece 9 and the contact surface 83 of the die 50 are parallel to each other. Further, the reference axis L1 of the striking device 40 passes through the joining position 85 provided on the article 9 to be joined. If it moves in this way, it will progress to step b6.

  In step b6, the control means 73 moves the base 45 to the target position along the reference axis L1. The target position is the position calculated in step b4. As shown in FIG. 16 (4), when the base 45 is moved to the target position, the contact surface 83 of the die 50 does not come into contact with the workpiece 9 and comes into surface contact with the workpiece 9. .

  When the displacement amounts D1, D2 and D3 given from the displacement sensors 84 become the displacement amounts representing the state in which the workpiece 9 and the contact surface 83 are in contact, the control means 73 causes the die 50 to move to the workpiece 9. Judged to be in surface contact. For example, the displacement amount representing the contact state is a displacement amount at which the gap between the die 50 and the workpiece 9 becomes zero. As described above, when the control unit 73 brings the die 50 into surface contact with the workpiece 9, the control unit 73 proceeds to step b <b> 7 and ends the die contact operation.

  17-20 is a figure for demonstrating the movement amount calculation formula. The die 50 extends perpendicularly to a first straight line K1 that connects two of the three displacement sensors 84a, 84b, 84c, for example, the first displacement sensor 84c and the second displacement sensor 84a, and sets the reference axis L1. The reference axis L1 is displaced by the first angle θ1 around the first rotation axis N1 that passes. Further, the reference axis L1 is displaced by the second angle θ2 around the second rotation axis N2 that is parallel to the first straight line K1 and passes through the reference axis L1. Note that the virtual end face of the die 50 extends parallel to the reference axis L1.

FIG. 17 is a front view showing the die 50 in a simplified manner, and FIG. 18 is a cross-sectional view showing the die structure 43 as viewed from the section line S18-S18 in FIG. Of the three displacement sensors 84a, 84b, 84c, the distance between the first displacement sensor 84c and the second displacement sensor 84a on the virtual end face of the die 50 is M1. The first displacement amount detected from the first displacement sensor 84c is D1, and the second displacement amount detected from the second displacement sensor 84a is D3. In this case, the first angle θ1 described above is expressed by the following equation.
θ1 = tan−1 ((D3−D1) / M1)
Here, tan-1 is an inverse trigonometric function of a tangent function, and is a so-called arc tangent.

  For example, the first rotation axis N1 is a straight line N1 perpendicular to the first straight line K1 connecting the first displacement sensor 84c and the second displacement sensor 84a, and passes through the intersection of the virtual end face of the die 50 and the reference axis L1.

FIG. 19 is a simplified front view showing the die 50, and FIG. 20 is a cross-sectional view showing the die structure 43 as viewed from the section line S20-S20 in FIG. Of the three displacement sensors 84a, 84b, 84c, the distance between the intermediate point C between the first displacement sensor 84c and the second displacement sensor 84a on the virtual end face of the die 50 and the third displacement sensor 84b is M2, When the third detection amount detected from the third displacement sensor 84b is D2, the second angle θ2 described above is washed by the following equation.
θ2 = tan−1 (Q−D2) / M2)
Q = (D3-D1) / 2
Here, tan-1 is an inverse trigonometric function of a tangent function, and is a so-called arc tangent.

  For example, the second rotation axis N2 is a straight line N2 perpendicular to the second straight line K2 connecting the intermediate point C between the first displacement sensor 84c and the second displacement sensor 84a and the third displacement sensor 84b. It passes through the intersection of the end surface and the reference axis L1.

  The control means 73 calculates the first angle θ1 and the second angle θ2 described above based on the given angular displacement sensors 84a, 84b, 84c, and sets the reference axis L1 around the first rotation axis N1 at the first angle θ1. In addition to the angular displacement, the angular displacement is performed around the second rotation axis N2 by the second angle θ2. Thus, as shown in FIG. 16 (3), the virtual end face of the die 50 and the surface of the workpiece 9 can be adjusted to be parallel. In other words, the joining surface of the workpiece 9 and the reference axis L1 can be adjusted to a vertical posture.

  When the posture is adjusted, the displacement amounts detected from the displacement sensors 84a, 84b, 84c become equal. When the die 50 is displaced along the reference axis L1 so that the amount of displacement detected from each of the displacement sensors 84a, 84b, 84c becomes zero in this state, the die 50 is moved as shown in FIG. 16 (4). It can move to the position which contacts the to-be-joined object 9 without hitting. The movement amount calculation formula described above is an example of the present embodiment, and other calculation formulas may be used.

  Further, another method for calculating the movement amount of the die 50 will be described. 21 and 22 are diagrams for explaining another calculation method. It is assumed that the displacement sensors 84a, 84b, and 84c are arranged at 120 ° intervals at positions that are separated from the reference axis L1 by a predetermined distance R in the radial direction. Further, the protruding amounts from the die 50 are α, β and γ, respectively.

  In the tool coordinate system, a virtual plane ABC including a movement amount for moving the tool by (α + β + γ) / 3 in the Z-axis direction in which the reference axis L1 extends, and tip positions A, B, C of the displacement sensors 84a, 84b, 84c. If the normal vector V is combined with the rotational movement to coincide with the reference axis L1, the workpiece lower surface and the die 50 can be brought into close contact with each other by a single robot movement operation.

At this time, the normal vector V of the virtual plane ABC is expressed by the following equation.
V = (− √3 · (β + γ) / (α + β + γ), (2 · α−β−γ) /
(Α + β + γ), −3 · R / (α + β + γ))
Therefore, if the rotation amount is calculated so that the direction coincides with the Z-axis direction vector (0, 0, 1) and the die 50 is moved according to the rotation amount, the work lower surface and the die 50 are brought into close contact with each other. be able to.

  As described above, when the control means 73 performs the die contact operation, the die 50 can be reliably brought into surface contact even when the shape and the arrangement position of the article 9 are varied. Accordingly, it is possible to prevent the joining operation from being performed in a state where a gap is generated between the die 50 and the workpiece 9. Even if a large force is applied to the workpiece 9 to push the rivet 1, the die 50 and the workpiece 9 are in surface contact, and the workpiece 9 is supported by the entire contact surface of the die 50. Can do. As a result, it is possible to prevent the workpiece 9 from being deformed undesirably and to improve the bonding quality.

  Further, when the moving position of the base 45 is clamped, the die 50 and the workpiece 9 can be brought into surface contact without clamping the accurate bonding position in advance, so that it is necessary to clamp the accurate bonding position. In addition, the time spent for teaching work can be reduced. Further, the teaching work does not have skill, and convenience can be improved. Further, based on the detection value of the die load cell 80c, the die 50 presses the workpiece 9 by moving the base 45 so that the pressing force applied to the workpiece 9 by the die 50 falls within a predetermined range. The pressing force can be set to a predetermined value, and the pressing force can be applied to the workpiece 9 without excess or deficiency.

  In addition, the die 50 can be brought into close contact with the workpiece 9 while the die side surface 9a of the workpiece 9 and the contact surface 83 of the die 50 are kept parallel. Accordingly, the die 50 does not come into contact with each other and come into contact with each other, and it is possible to prevent the article 9 and the die 50 from being damaged. Furthermore, by arranging the base 45 so that the reference axis L1 passes through the joining position of the article 9 to be joined, the rivet 1 can be accurately immersed in the joining position of the article 9 to be joined. Further, when moving the base 45 to the target position and the target posture, the operation of moving to the target posture and the operation of moving to the target position may be performed at the same time. Can be contacted.

  Further, even when the die side surface 9a of the workpiece 9 is formed into a curved surface, the surface information indicating the form of the die side surface 9a of the workpiece 9 is given in advance, so that the target position and target posture can be determined. It is possible to calculate with high accuracy. For example, the surface information is created based on CAD (Computer Aided Design) data obtained in advance for design.

  Further, the target position and the target posture can be set based on the detection result of the contact state detection sensor 84 described above, but it is sufficient that only the contact surface 83 of the die 50 is brought into contact with the workpiece 9. Alternatively, other configurations may be used. For example, as another embodiment, the contact state detection sensor 84 may use one displacement sensor instead of the three displacement sensors. This displacement sensor detects the relative distance between the die 50 and the workpiece 9 and gives the detection result to the control means 73. The control means 73 controls the robot arm 44 and moves the die 50 along the reference axis L1 until the relative distance given from the displacement sensor reaches a predetermined contact distance. Here, the contact distance is a distance at which the die 50 reliably contacts the workpiece 9. In this way, the die 50 can be brought into contact with the workpiece 9.

  As still another embodiment, the contact state detection sensor 84 may use one load sensor instead of the three displacement sensors. This load sensor detects a load applied from the workpiece 9 to the die 50 and supplies the detection result to the control means 73. The load sensor is realized by the above-described die load cell 80c. The control means 73 controls the robot arm 44 and moves the die 50 along the reference axis L1 until the load applied from the die load cell 80c reaches a predetermined contact load. Here, the contact load is a load applied from the workpiece 9 when the die 50 comes into contact with the workpiece 9. Even in this way, the die 50 can be reliably brought into contact with the workpiece 9.

  FIG. 23 is a flowchart illustrating the procedure of the plate thickness measurement operation of the bonding apparatus 101. FIG. 24 is a cross-sectional view for illustrating the procedure of the plate thickness measurement operation of the bonding apparatus 101. In step a2 of the bonding operation described above, the bonding apparatus 101 performs a plate thickness measurement operation for measuring the plate thickness of the workpiece 9 while sandwiching the workpiece 9 therebetween. The plate thickness of the workpiece 9 is a dimension in the parallel direction A of the workpiece 9 and is a dimension obtained by adding the parallel dimensions of the respective joining members 9 together. The control means 73 obtains the distance in the reference direction Z between the position of the die 50 and the punch 51 when the work piece 9 is sandwiched between the die 50 and the punch 51, and the distance is determined as the plate thickness of the work piece 9. To do.

  First, at step c0, as shown in FIG. 24 (1), when the rivet 1 is pressed against the reference member 86 with a predetermined load P determined by the punch 51, a reference displacement amount T2 that is a displacement amount of the punch 51 is obtained. It is obtained in advance. The displacement amount of the punch 51 can be obtained based on the encoder value of the punch servomotor 60. The predetermined load P is preferably a load before the rivet 1 is immersed in the workpiece 9 and is a load that hardly deforms the base 45. The reference displacement amount T2 is a distance by which the punch 51 moves from the predetermined reference position toward the workpiece 9.

  The control means 73 stores the plate thickness dimension T1 and the reference displacement amount T2 of the reference member 86 in advance, and when preparation for the plate thickness measurement operation is completed, the process proceeds to step c1, and the control means 73 starts the plate thickness measurement operation. To do.

  In step c 1, the control means 73 controls the punch servomotor 60 and presses the rivet 1 against the workpiece 9 by the punch 51. As shown in FIG. 24 (2), the rivet 1 is pressed against the workpiece 9 with the first load P 1 that is smaller than the predetermined load P by the variable load. The control means 73 obtains a first displacement amount T3 that is the displacement amount of the punch 51 at the first load P1, and proceeds to step c2. The first displacement amount T3 is the distance that the punch 51 moves toward the workpiece 9 from a predetermined reference position.

  In step c <b> 2, the control means 73 controls the punch servomotor 60 to further press the rivet 1 against the workpiece 9 by the punch 51. As shown in FIG. 24 (3), the rivet 1 is pressed against the workpiece 9 with the second load P 2 that is larger than the predetermined load P by the variable load. The control means 73 obtains the second displacement amount T4 that is the displacement amount of the punch 51 at the second load P2, and proceeds to step c3. The second displacement amount T4 is a distance that the punch 51 moves toward the workpiece 9 from a predetermined reference position.

  In step c3, the control means 73 obtains the plate thickness of the workpiece 9 based on the displacement amounts T3 and T4 obtained in step c2 and step c3. First, the first displacement amount T3 and the second displacement amount T4 are interpolated and the third displacement amount T5, which is the displacement amount of the punch 51 when the workpiece 9 is pressed with a predetermined load P, is obtained. As the interpolation calculation, the displacement amount at the predetermined load P is obtained by interpolating the first displacement amount T3 and the second displacement amount T4.

  As a specific example, the first displacement amount T3 is obtained with a load P1 that is 200 N (20 kgf) smaller than the predetermined load P in step c2, and the second displacement amount T4 is obtained with a load P2 that is 200 N (20 kgf) larger than the predetermined load P in step c3. When obtained, the third displacement amount T5 is an average value of the first displacement amount T3 and the second displacement amount T4.

  After obtaining the third displacement amount T5, the control means 73 then subtracts the third displacement amount T5 from the reference displacement amount T2, and adds the plate thickness dimension T1 of the reference member 86 to the subtraction result T6. This addition result is set as the plate thickness dimension of the workpiece 9. That is, the plate thickness dimension is indicated by T2−T5 + T1. Here, T2 is the reference displacement amount T2, T5 is the third displacement amount, and T1 is the plate thickness dimension T1 of the reference member 86. When the thickness of the workpiece 9 is calculated, the control unit 73 proceeds to step c4, and ends the plate thickness measurement operation in step c4.

  As described above, the control unit 73 performs the plate thickness measurement operation, whereby the plate thickness of the workpiece 9 can be accurately obtained for each bonding. By obtaining the plate thickness of the workpiece 9 for each bonding and changing the bonding conditions according to the plate thickness, even if the plate thickness of the workpiece 9 varies, the bonding quality can be kept constant. it can.

  It is difficult to measure the displacement T5 at the predetermined load P while maintaining the predetermined load P during the joining operation. In the present embodiment, the displacement amounts T3 and T4 are obtained before and after the predetermined load P, and the values are interpolated, whereby the displacement amount T5 at the predetermined load P can be easily obtained.

  Further, by obtaining the reference displacement amount T2 in advance and comparing the reference displacement amount T2 with the displacement amounts T3 and T4 when the workpiece is actually measured, the influence of the deflection of the base 45 is reduced. Measurement accuracy can be improved. Moreover, by setting the predetermined load P to a load with a small deflection of the base 45, the influence of the deflection of the base 45 can be reduced, and the measurement accuracy can be further improved. Further, by measuring the dimension of the rivet 1 in the axial direction and calculating the thickness of the workpiece 9 in consideration of the dimension, the thickness of the workpiece 9 can be obtained more accurately.

  Further, as shown in FIGS. 24 (1) to 24 (3), the reference displacement amount T2, the first and second displacement amounts T3, T4 in a state where the workpiece 9 is sandwiched between the clamp shaft 53 and the die 50. By measuring this, it is possible to measure the plate thickness of the article 9 without a gap formed between the joining members 2 and 3. Further, by measuring the plate thickness of the workpiece 9 after performing the die contact operation as described above, the plate thickness measurement accuracy can be further improved. Further, by obtaining the axial displacement amount of the punch 51 from the encoder value of the punch motor, it is not necessary to separately provide a measuring means for measuring the member to be joined, and the structure can be simplified.

  As another embodiment, a clamp shaft 53 may be used instead of the punch shaft 52 in the above-described embodiments. By using the clamp shaft 53, the thickness of the workpiece 9 can be measured without the rivet 1, and the thickness of the workpiece 9 can be measured more accurately. As yet another embodiment, a plate thickness measuring means for accurately measuring the plate thickness of the article 9 may be provided separately.

  FIG. 25 is a flowchart showing a procedure of another plate thickness measurement operation of the present embodiment. FIG. 26 is a cross-sectional view for illustrating the procedure of another plate thickness measurement operation. As described above, the plate thickness of the workpiece 9 may be measured using the clamp shaft 53 as another plate thickness measurement operation.

  The plate thickness measuring means for measuring the plate thickness is realized by the control means 73 and the encoders of the punch servomotor 60 and the clamp servomotor 55. The control means 73 includes a clamp body reference position that is a position in the reference direction Z of the clamp shaft 53 when the clamp shaft 53 contacts the die 50 with no pressing force or a small pressing force, and a reference pressing force determined in advance by the clamp shaft 53. A storage unit is provided for storing the die displacement amount in the reference direction Z of the die 50 when pressure is applied to the die 50.

  The encoder serves as a detection unit that detects a clamp shaft pressing position in the reference direction of the clamp shaft 53 when the workpiece 9 is pressed by the clamp shaft 53 with a predetermined reference pressing force.

  Further, the control device 73 acquires the clamp shaft reference position, the die displacement amount, and the clamp shaft pressing position from the storage unit and each encoder, and the die 50 when the reference pressing force is applied to the die 50 by the clamp shaft 53. To the clamp shaft 53 is calculated as the dimension of the workpiece 9.

  The control device 73 measures the plate thickness by performing the operations of steps h0 to h3. First, in step h0, as shown in FIG. 26 (1), the clamp shaft 53 when the clamp shaft 53 is brought into direct contact with the die 50 without arranging a member between the die 50 and the clamp shaft 53 is provided. Is determined as a zero position O. The setting of the zero position is obtained in a state where the clamp shaft 53 is brought into contact with the die 50 with no pressing force or as small a pressing force as possible. In addition, a coordinate axis for thickness measurement is set based on the obtained zero position O. The coordinate axis for measuring the plate thickness has the zero position O as the origin, the reference direction Z from the zero position O toward the die structure 43 as a negative direction, and the reference direction Z from the zero position O toward the punch structure 41 as a positive direction. And In this way, the state in which the clamp axis coordinate Zc and the punch axis coordinate Zp are in contact with the die 50 without being pressed is set to zero, and the direction of the coordinates is shown in FIG.

  In step h0, when a predetermined load Pc is applied to the die 50, an amount of deflection of the base 45 is obtained. Specifically, when a predetermined load Pc is applied to the die 50 by the clamp shaft 53, a deflection displacement amount ΔC that the die 50 is displaced from the zero position O in the reference normal direction Z is obtained.

  The control means 73 stores the coordinate axis for thickness measurement and the deflection displacement amount ΔC in advance, and when preparation for the thickness measurement operation is completed, the control means 73 proceeds to step h1, and the control means 73 starts the thickness measurement operation.

  In step h <b> 1, the control means 73 controls the clamping servo motor 55 and presses the workpiece 9 by the clamp shaft 53. As shown in FIG. 26 (2), the workpiece 9 is pressed with a predetermined load Pc by the clamp shaft 53. The control means 73 obtains the coordinate Zc of the clamp shaft 53 and the coordinate Zp of the punch shaft 52 in the plate thickness measurement coordinate axes. The coordinates of the clamp shaft 53 and the punch shaft 52 on the coordinate axes for measuring the plate thickness can be obtained based on the encoder value of the servo motor 55 for clamping and the encoder value of the servo motor 60 for punch. When the coordinates Zc and Zp of the clamp shaft 53 and the punch shaft 52 are obtained, the process proceeds to step h2.

In step h2, the thickness dimension of the workpiece 9 is calculated by substituting the coordinates Zc and Zp of the clamp shaft 53 and the punch shaft 52 into a predetermined thickness measurement formula. When the control means 73 calculates the plate thickness T10 of the article 9 to be joined, the control means 73 proceeds to step h3 and ends the plate thickness measurement operation at step h3. For example, a predetermined plate thickness measurement formula is given by the following formula.
T10 = Zc−ΔC
Here, T10 is the thickness of the workpiece. Zc is a Z-axis coordinate calculated from the encoder value of the clamp shaft when pressurization is completed at a predetermined pressure Pc. ΔC is the amount of deflection of the C frame which is the base 45 due to the load at the time of clamping.

  The plate thickness measurement may be performed by performing such a plate thickness measurement operation. By performing the plate thickness measurement procedure shown in FIG. 25, the plate thickness can be measured in a state where the workpiece 9 is clamped, and the bonding operation and the plate thickness measurement can be performed simultaneously. It can be carried out. In this case, since the plate thickness which is the dimension of the workpiece 9 can be measured in a state where the clamp shaft 53 presses the workpiece 9 with a predetermined reference pressure, there is a gap between the bonding members 2 and 3. Even in the case, the thickness of the workpiece 9 in the state where the gap is eliminated can be measured, and the thickness can be measured with high accuracy. Further, by calculating the distance between the clamp shaft 53 and the die 50 on the basis of the die displacement amount, even when the die 50 is displaced due to the deflection caused by the reference pressing force, the deflection is corrected to be more accurate. It is possible to measure the thickness of the object 9 to be joined.

  FIG. 27 is a graph showing the relationship between the coordinate Zp of the punch shaft 52 and the plate thickness of the rivet workpiece 9 when the caulking operation is completed. The plot points 87 shown in FIG. 27 indicate the punch shaft 52 such that the punch-side surface 9b of the rivet 1 and the punch contact surface 1a of the workpiece 9 are substantially flush for each plate thickness of the workpiece 9. The absolute value | Zp | of the coordinate Zp, in other words, the distance from the die 50 of the rivet is shown.

Even if the thickness ratios of the bonding members 2 and 3 constituting the workpiece 9 are different, if the plate thickness of the workpiece 9 is the same, the punch-side surface 9b of the rivet 1 and the workpiece 9
The coordinate Zp of the punch shaft 52 that is flush with the punch contact surface 1a is determined as one. By immersing the rivet 1 up to the coordinate Zp of the punch shaft 52, the surface of the rivet immersed in the workpiece 9 can be flush with the surface of the workpiece.

  The relationship between the plate thickness of the workpiece 9 and the target coordinate Zp of the punch shaft 52 is represented by a linear straight line 88 on the graph. That is, as the plate thickness of the workpiece 9 increases, the coordinate Zp of the target punch shaft 52 is increased, in other words, the distance from the large rivet 50 is increased, thereby increasing the distance between the rivet 50 and the rivet 9. Can be leveled.

  Ideally, the coordinate Zp of the punch shaft 52 is equal to the thickness of the joined portion of the object to be joined, as indicated by the dashed line 89 having a slope of 1 on the graph. However, in reality, the object to be joined is plastically deformed due to rivet driving, resulting in a change in plate thickness. Therefore, by predicting the plate thickness change resulting from this rivet driving based on experimental data, and correcting the target coordinate Zp of the punch shaft 52 according to the predicted amount, the rivet 1 and the object to be joined can be more accurately obtained. The surface with 9 can be made flush.

  FIG. 28 is a flowchart showing the procedure of the rivet pushing amount determination operation of the joining apparatus 101. The joining apparatus 101 determines an appropriate rivet pushing amount according to the target coordinate Zp of the punch shaft 52 based on the measured thickness of the workpiece 9 in step a3 of the joining operation described above. The rivet 1 is pushed into the workpiece 9 with the determined pushing amount.

  Based on the thickness of the workpiece 9, the control means 73 stores an arithmetic expression for calculating the amount of rivet pushing so that the punch contact surface 1 a of the rivet 1 is flush with the punch side surface 9 b. Select an appropriate push amount each time you perform an action. First, at step d0, the control means 73 stores an arithmetic expression in advance, and when preparation for the pushing amount determining operation is completed, the control means 73 proceeds to step d1, and the control means 73 starts the rivet pushing amount determining operation.

  In step d1, the operations of steps c1 to c4 described above are performed, and the thickness of the workpiece 9 is acquired. If the control means 73 acquires the plate | board thickness of the to-be-joined object 9, it will progress to step d2.

  In step d2, the control means 73 calculates the pushing amount by which the rivet 1 can be pushed flush with the workpiece 9 from the arithmetic expression based on the measured thickness of the workpiece 9 and step d3. Proceed to In step d3, the control means 73 ends the pushing amount determining operation. The control means 73 controls the punch servomotor 60 so as to push the rivet 1 by the calculated pushing amount in the joining operation.

  Moreover, the control means 73 may memorize | store the database which shows the relationship between the plate | board thickness of the to-be-joined thing 9 used as the same surface, and the pressing amount instead of a computing equation. In this case, the control means 73 calculates the indentation amount with reference to the database based on the plate thickness of the workpiece 9 measured for each joining.

  In this way, the plate thickness is measured for each object 9 to be bonded, and the rivet 1 and the punch side surface of the object to be bonded are flush with each other by determining the amount of pushing the rivet 1 in accordance with the measurement result. be able to. This can improve the aesthetics and improve the bonding quality.

  FIG. 29 is a side view for explaining deflection correction of the base 45 by the robot arm 44. FIG. 29 (1) shows a state where the base 45 is not bent, and FIGS. 29 (2) and 29 (3) show a state where the base 45 is bent. FIG. 29 (2) shows an embodiment of the present invention in which the deflection of the base 45 is corrected, and FIG. 29 (3) shows a comparative example in which the deflection of the base 45 is shown. Indicates a state in which no correction is made. FIG. 30 is a graph showing the relationship between the pressing force applied to the die structure 43 and the deflection of the base 45. In FIG. 30, a solid line 90 indicates the relationship between the first deflection amount ΔZ deflected in the direction along the reference axis L1 and the pressing force with which the punch shaft 52 presses the workpiece. In FIG. 30, the broken line 89 shows the relationship between the second deflection amount ΔY that is perpendicular to the reference axis L <b> 1 and away from the robot 44 and the pressing force with which the punch shaft 52 presses the workpiece. The first deflection amount ΔZ and the second deflection amount ΔY increase proportionally as the pressing force increases.

  When the punch 51 immerses the rivet 1 in the workpiece 9, a large force is applied to the workpiece 9. For example, in spot resistance welding, the force applied to the workpiece 9 is 10 kilonewtons (1 ton weight), whereas in the joining using the rivet 1, the force applied to the workpiece 9 is 50 kilonewtons. (5 tons). Therefore, the deflection of the circumferential end 48 of the base 45 that supports the workpiece 9 also increases. In the present embodiment, a load applied to one end 48 in the circumferential direction of the base 45 is detected by a die load cell 80 c provided on the die support member 69. Then, information indicating the load is given to the control means 73. The control means 73 can reduce the deformation of the article 9 due to the deflection of the base 45 by moving the base 45 based on the detected load. On the other hand, in the form of a comparative example, the to-be-joined object 9 may deform | transform according to the bending of the base 45, and there exists a possibility that joining quality may fall.

  FIG. 31 is a flowchart illustrating the procedure of the deflection amount correcting operation of the joining apparatus 101. The bonding apparatus 101 moves the robot arm 44 so as to correct the deformation of the base 45 based on the load detected from the die load cell 80c in step a3 of the bonding operation described above.

  The control means 73 stores a database indicating the amount of movement of the robot arm 44 that keeps the position of the die 50 constant even if the base 45 is deformed. The database moves the base 45 in the direction intersecting the reference direction Z and the amount of movement to move the base 45 in the reference direction Z in order to maintain the position of the die 50 for each load applied to the base 45. At least two pieces of information on the amount of movement are shown.

  First, at step e0, the control means 73 stores the above-described database, and when preparation for the deflection amount correction operation is completed, the process proceeds to step e1, and the control means 73 starts the deflection amount correction operation.

  In step e1, the load applied to the die 50 by the die load cell 80c is detected and applied to the control means 73. The control means 73 acquires the load detected by the die load cell 80c, and proceeds to step e2. In step e2, the control means 73 refers to the database based on the acquired load, calculates the robot arm movement amount that keeps the position of the die 50 constant, and proceeds to step e3. In step e3, the control means 73 controls the robot arm driving means 77, moves the robot arm 44 by the calculated robot arm movement amount, and proceeds to step e4. In step e4, the control means 73 determines whether or not the state where the load is applied is continued, and when it is determined that the state is continued, returns to step e1. If it is determined that the state in which the load is applied has been completed, the process proceeds to step e5, and the deflection amount correcting operation is terminated in step e5.

  Thus, by moving the base 45 in accordance with the deformation of the base 45, it is possible to prevent the article 9 to be joined held by the holding device 102 from being deformed together with the base 45. In particular, the striking device 40 has a larger load applied to the workpiece 9 and a larger deflection of the base 45 than other joining devices. As in the present embodiment, according to the deformation of the base 45, the base 45 is moved in at least two directions of the reference direction Z and the direction intersecting the reference direction, so that the article 9 is joined to the base 45. In addition, deformation can be prevented.

  FIG. 32 is a flowchart showing the procedure of the clamp pushing load adjustment operation of the joining apparatus 101. In step a3 of the above-described joining operation, the control device 101 adjusts the pressing force of the workpiece 9 by the clamp member 53 to a predetermined value.

  First, at step g0, the control means 73 stores an appropriate pressing force of the clamp shaft 53 applied to the workpiece 9, and when the preparation of the clamp pushing load is completed, the control means 73 proceeds to step g1 and the control means 73 pushes the clamp pushing Start the load adjustment operation.

  In step g1, the control means 73 acquires the pressing force that the clamp shaft 53 applies to the workpiece 9 from the clamp load cell 80a, and proceeds to step g2. In step g2, the control means 73 determines whether or not the acquired measured pressing force is a preset pressing force that is set in advance. The preset pressing force that is set in advance is a pressing force that can hold the workpiece 9 without any problem during the bonding process. If the measured pressing force does not match the set pressing force, the process proceeds to step g3. When the measured pressing force matches the set pressing force, the process proceeds to step g4.

  In step g3, the control means 73 controls the servo motor 55 for clamping, displaces the clamp shaft 53 so that the pressing force applied to the workpiece 9 by the clamp shaft 53 becomes the set pressing force, and proceeds to step g4. . In step g4, the control means 73 determines whether or not to continue the indentation load adjustment operation. If the indentation load adjustment operation is to be continued, the process returns to step g1. If the load adjustment operation is to be terminated, the process proceeds to step g5, and the load adjustment operation is terminated at step g5.

  In this way, the pressing force that the clamp shaft 53 applies to the workpiece 9 is acquired, and the clamp shaft 53 is moved based on the acquired measured pressing force. As a result, the measured pressing force and the set pressing force can be matched. For example, even when the position where the workpiece 9 is provided and the thickness of the workpiece 9 vary, or when a gap is formed between the respective joining members 2 and 3, the workpiece can be joined with an appropriate clamping force. Can be pinched. Thereby, it can prevent that the to-be-joined object 9 shakes or deform | transforms, and can improve joining quality.

  Further, the control means 73 may acquire information indicating the movement state of the punch 51 from the encoder value of the punch servomotor 60 and adjust the pressing force of the clamp shaft 53 based on the acquired encoder value. In this case, the encoder of the punch servomotor 60 serves as a processing state acquisition unit that acquires a joining processing state by the processing unit. The control means 73 may control the servo motor 55 for clamping so that the pressing force of the workpiece 9 by the clamp shaft 53 becomes a value corresponding to the bonding processing state following the bonding processing state.

  33 and 34 are flowcharts specifically showing an example of the joining operation. 35 to 39 are cross-sectional views of the striking device 40 showing a procedure for specifically explaining the joining operation, and FIG. 35 is a cross-sectional view showing a start state of the joining operation. FIG. 36 is a cross-sectional view showing a state in which the die 50 is in contact with the workpiece. FIG. 37 is a cross-sectional view showing a state in which the clamp shaft 53 is in contact with the workpiece. FIG. 38 is a cross-sectional view showing a state in which the rivet 1 is in contact with an object to be joined. FIG. 39 is a cross-sectional view showing a state where the rivet 1 is immersed in the workpiece. 40 and 41 are cross-sectional views showing the striking device 40 in the ready state. In the joining operation, the control means 73 performs the above-described die contact operation, plate thickness measurement operation, rivet push amount determination operation, deflection correction operation, and clamp push load adjustment operation.

  First, in step f0, a preparatory operation for performing the joining operation is performed, and when the joining operation can be performed, the process proceeds to step f1. In Step f1, the power for starting the joining operation is turned on to the joining equipment 100. The control means 73 determines that a joining operation start command has been given by turning on the power, and proceeds to step f2.

  In step f2, the control means 73 sets the intruder detection sensor of the safety fence 104 in a movable state, checks whether there is any abnormality in the joining equipment 100, and proceeds to step f3 when determining that there is no abnormality. If it is determined that there is an abnormality in the joining facility 100, a warning is issued and the joining operation is stopped until the abnormality is resolved.

  In step f3, the control means 73 controls the robot arm drive means 77 to move the base 45 to a predetermined initial position. When the base 45 is displaced to the initial position, the process proceeds to step f4. In step f4, the striking device 40 is brought into the first preparation state. The first preparation state is a state in which the rivet 1 supplied from the rivet filling device 78 is easily held. For example, as shown in FIG. 40, the first preparation state is a state in which the punch 51 is immersed closer to the main body side of the punch shaft 52 than the filling hole 66 and the punch 51 is disposed at a position close to the filling hole 66. When the striking device 40 is in the first state, the process proceeds to step f5.

  In step f5, the control means 73 controls the rivet holding means 74 so that the rivet 1 can be held. Specifically, the suction air valve provided in the rivet holding means 74 is opened, and the process proceeds to step f6. In step f6, the control means 73 controls the rivet filling device 78. The rivet 1 is supplied to the filling space 67 by the rivet filling device 78, and the process proceeds to step f7.

  In step f7, the control means 73 determines whether or not the rivet 1 is held. For example, the control means 73 is given information indicating the air flow rate from a sensor that detects the flow rate of air adsorbed by the rivet holding means 74. The control means 73 determines that the rivet 1 is held by the change in the air flow rate. If it is determined that the rivet 1 is held, the process proceeds to step f8. If it is determined that the rivet 1 is not determined, the process returns to step f6.

  In step f8, the control means 73 sets the striking device 40 in the second preparation state. The second preparation state is a position where rivet driving is started. Therefore, the robot arm driving means 77 is controlled to move to a position close to the joining position of the workpiece 9. In moving to the second preparation state, a die contact operation is performed as shown in FIGS. By performing the die contact operation, the contact surface 83 of the die 50 is brought into surface contact with the punch side surface 9a of the workpiece 9 and the axis of the die 50 and the joining position of the workpiece 9 are arranged coaxially. Can do.

  The control means 73 controls the clamp servo motor 55 to move the clamp shaft 53 relative to the workpiece 9. The control means 73 controls the punch servomotor 60 to move the punch shaft 52 relative to the workpiece 9. Thus, the control means 73 moves the clamp shaft 53 and the punch shaft 52 independently.

  For example, in the second preparation state, as shown in FIG. 41, the clamp shaft 53 is moved to a position close to the workpiece 9 and the punch shaft 52 is moved away from the workpiece 9 by a predetermined running distance. It is in the state. When the second preparation state is thus established, the process proceeds to step f9.

  In step f9, the control means 73 shifts to the automatic driving operation mode and proceeds to step f10. In step f10, the control means 73 measures the state quantity given from each means. The predetermined state quantity includes each position command value of each of the clamping servo motor 55 and the punch servo motor 60, each actual position value, each motor current, and each detected value of the load cells 80a, 80b, and 80c. The motor position command value is a command value commanded by the control means 73. The actual position value of the motor can be obtained by an encoder. The motor current is a current value required to rotate the motor at a predetermined moving speed. Such measurement of each state continues until the bonding is completed. When the state measurement is started, the process proceeds to step f11.

  In step f <b> 11, the control unit 73 controls the clamp servo motor 55 to move the clamp shaft 53 toward the workpiece 9. The control means 73 controls the clamping servomotor 55 based on the detected load value given from the clamping load cell 80a. The workpiece 9 is pressed with a predetermined load by the clamp shaft 53. The predetermined load determined in advance is a load that can eliminate the gap between the joining members 2 and 3 and can clamp the article 9 to be joined. The predetermined load of the clamp shaft 53 is set to about 6 kilonewtons (600 kgf) for a rivet having a diameter of 4 mm, for example. As a result, as shown in FIG. 37, the workpiece 9 is clamped and held by the clamp shaft 53 and the die 50, and the process proceeds to step f12.

  In step f <b> 12, the control unit 73 controls the punch servomotor 60 to move the punch shaft 52 toward the workpiece 9. The control means 73 controls the punch servomotor 60 based on the detected load value given from the punch load cell 80b. Then, as described above, the punch 51 obtains the first displacement amount T3 that is smaller than the predetermined load P by the variation load and the second displacement amount T4 that is larger than the predetermined load P by the variation load, and proceeds to step f13. For example, in a rivet having a diameter of 4 mm, the predetermined load P of the punch 51 is set to 50 kilonewtons (5 tons). The variable load may vary from measurement to measurement.

  In step f13, the control means 73 performs the plate thickness measurement operation described above. Based on the displacement amounts T3 and T4 obtained in step f12 and the plate thickness dimension T1 and the reference displacement amount T2 of the reference member 86 stored in advance, the control means 73 performs the plate of the workpiece 9 to be joined. Calculate the thickness. When the thickness of the workpiece 9 is calculated by the punch 51, the process proceeds to step f14. The plate thickness measurement operation may be obtained according to another plate thickness measurement operation shown in FIG.

  In step f14, it is determined whether or not the plate thickness of the workpiece 9 calculated in step f13 exceeds a predetermined plate thickness range. When the plate thickness of the workpiece 9 exceeds a predetermined plate thickness range, a warning is issued and the process proceeds to step f23 to end the bonding operation. On the other hand, when the plate thickness of the article 9 is within a predetermined plate thickness range, the process proceeds to step f15.

  In step f15, the control means 73 checks whether or not an operation for adjusting the pushing amount for pushing the rivet is set according to the thickness of the article 9 to be joined. This setting is preset. If the operation for adjusting the pushing amount is set, the process proceeds to step f16, and the rivet pushing amount determining operation is performed in step f16. The control means 73 calculates an appropriate pushing amount and proceeds to step f17.

  If it is determined in step f15 that the pressing amount adjusting operation is not set, the process proceeds to step f17 using a predetermined pressing amount as a setting condition. In step f17, as shown in FIG. 38, the rivet 1 is moved toward the workpiece 9 so that the set push amount is reached, and the process proceeds to step f18.

  In step f18, the control means 73 adjusts the clamp pushing load with the movement of the punch 51 so as to keep the pressing force by the clamp shaft 53 constant. At this time, the control means 73 performs a deflection amount correcting operation along with the movement of the punch 51 so that the article 9 is not displaced.

  In step f18, it is checked whether or not the pressing force applied to the workpiece 9 by the clamp shaft 53 exceeds a predetermined pressing force range. If the predetermined pressing force range is exceeded, a warning is issued and the process proceeds to step f23 to end the joining operation. Further, when the pressing force that the clamp shaft 53 applies to the workpiece 9 in step f18 falls within a predetermined pressing force range, the joining process is permitted. Proceed to step f19. Further, if the pressing force of the workpiece 9 by the clamp shaft 53 is equal to or higher than a predetermined reference pressing force, the joining process is allowed.

  In step f19, it is checked whether or not the punch 51 has been pushed by the determined pushing amount. In other words, it is determined whether or not the position of the punch 51 has reached the set push amount. If the set push amount has not been reached, the process returns to step f17. In step f19, when the position of the punch 51 reaches the set pressing amount, the control means 73 determines that the rivet 1 has reached the target pressing amount, as shown in FIG. move on. In step f20, the control means 73 sets the striking device 40 in the first preparation state, and proceeds to step f21.

  In step f21, the control means 73 ends the measurement of the state quantity given from each means, and proceeds to step f22. In step f22, the control means 73 closes the suction air valve provided in the rivet holding means 74, and proceeds to step f23. In Step f23, the clamping servomotor 55 and the punching servomotor 60 are turned off, the intruder detection sensor of the safety fence 104 is stopped, and the joining operation is finished.

  The striking device 40 has a large pressing force applied to the workpiece 9 by the rivet 1. As a result, the deformation of the workpiece 9 and the deformation of the striking device 40 greatly affect the bonding quality. Therefore, in order to improve the bonding quality, it is very important to correct the deformation and prevent the deformation.

  According to the embodiment of the present invention, the object 9 is pressed by the rivet 1 in a state where the contact surface 83 of the die 50 is in surface contact with the object 9 reliably. This prevents the workpiece 9 from being deformed and allows the joining members 2 and 3 to be joined. Further, by using the three displacement sensors 84a, 84b, 84c as in the present embodiment, the joining position and the protrusion 50a of the die 50 can be moved to a position aligned along the reference axis L1. As a result, the rivet can be reliably immersed in the joining position, and the rivet 1 can be prevented from being immersed in the workpiece 9 at a position shifted from the joining position.

  In this embodiment, the robot arm 44 is moved not only in the reference direction Z but also in a direction perpendicular to the reference direction Z, and the workpiece 9 is held at a fixed position regardless of the deformation of the base 45. Accordingly, the displacement and deformation of the workpiece 9 due to the deformation of the base 45 can be prevented. In this case, it is not necessary to separately provide a means for correcting the deflection of the base 45, such as an equalizer, in the striking device 40, and the striking device 40 can be reduced in weight.

  Further, when the load is obtained from the motor current of the servo motor, the current necessary for acceleration / deceleration is superimposed and an accurate load cannot be calculated. The servo motors 55 and 60 are affected by the inertial force during rotation, and the motor current changes depending on the difference in the initial speed. In the present embodiment, the load applied to the base 45 is measured by the die load cell 80c. As a result, the load applied to the base 45 can be measured with higher accuracy than when the load is obtained from the motor current.

  In addition, regardless of how the rivet 1 is immersed, the pressing force of the clamp shaft 53 can be kept constant, and the workpiece 9 is not clamped with an excessive clamping force. As a result, the deformation of the workpiece 9 due to the clamping of the workpiece 9 can be prevented. Further, by moving the clamp shaft 53, the operation of teaching the position of the base 45 and the operation of confirming the clamping of the object to be bonded can be performed without applying a pressing force to the object 9 to be bonded. Can be improved.

  The clamping servomotor 55 can arbitrarily adjust the pressing force by the clamp shaft 53 as compared with other driving means such as a spring body, air, and hydraulic pressure. The pressing force by the clamp shaft 53 can be easily adjusted according to the degree of immersion and the shape of the rivet 1. As a result, the bonding quality can be further improved.

  Further, the punch servomotor 60 can directly apply the driving force to the punch shaft 52 without having to resist the spring force as in the prior art, and the punch servomotor 60 can be downsized. Further, since it is not necessary to resist the spring force, it is not necessary to excessively increase the structural strength, and the weight can be reduced. Further, the accuracy of plate thickness measurement by the clamp shaft 53 can be improved.

  In addition, by measuring the state quantity given from each means in step f10, it is possible to confirm the joining state and obtain the rivet length, and the convenience can be further improved. The rivet length can be obtained based on the encoder values of the servo motors 55 and 60. The control means 73 can further improve the joining quality by setting the pushing amount based on the rivet length in addition to the thickness of the object to be joined.

  FIG. 42 is a perspective view showing a moving path of the clamp shaft 53 in the present invention. FIG. 43 is a perspective view showing a moving path of the clamp shaft 53 in the comparative example. When a plurality of joining positions are set on the workpiece 9, the striking device 40 is sequentially moved to each joining position by the robot arm driving means 77 and pushes the rivet 1.

  When the clamp shaft 53 moves from the standby position 201 at one joining position 200 to the standby position 203 at the other joining position 202, the control means 73 drives the base 45 to move and simultaneously displaces the clamp shaft 53. As a result, the control means 73 can move the clamp shaft 53 along a path that shortens the moving path after avoiding the obstacle 204.

  Further, the control means 73 moves the clamp shaft 53 in the reference direction Z as indicated by an arrow 207 by the clamp servomotor 55. Further, the control means 73 moves the clamp shaft 53 in the direction outside the reference direction Z as indicated by an arrow 209 by the robot arm 44. That is, the energy required for moving the base 45 can be reduced without moving the base 45 itself in the reference direction Z.

  Further, by performing the rivet holding operation while moving from one standby position 201 to the other standby position 203, the joining operation can be further shortened in a short time. The controller 73 may displace the clamp shaft 53 by using not only the clamp servomotor 55 but also the punch servomotor 60 in moving the joining position.

  On the other hand, in the hammering device of the comparative example shown in FIG. 43, the clamp shaft 53 cannot be moved independently with respect to the base 45. Therefore, it is necessary to move the clamp shaft 53 in the direction other than the reference direction Z and the reference direction as indicated by the arrow 205 by the robot arm 44. In this case, the movement path of the base 45 becomes long, energy required for moving the base 45 becomes large, and it takes time to move the clamp.

  Therefore, as in the present embodiment, by separately displacing the clamp shaft 53 and the punch shaft 52 with respect to the base 45, the time required for a plurality of joints can be shortened as compared with the joining device of the comparative example. And the required energy can be reduced.

  FIG. 44 is a cross-sectional view schematically showing a striking device 440 according to another embodiment of the present invention. The striking device 440 differs from the striking device 40 shown in FIG. 1 in the configuration for moving the clamp shaft 53, and the same configuration is shown for the remaining configuration. About the same structure, the same referential mark as the striking device 40 shown in FIG. 1 is attached | subjected, and description is abbreviate | omitted.

  In the punch structure 41, a clamping servo motor 55 is fixed to the main body 56. The servo motor 55 for clamping is formed in a ring shape and is arranged coaxially with the reference axis L1. The clamping servo motor 55 is connected to the rotation transmitting member 54 via a hollow clamping load cell 80a. The clamping load cell 80a is formed in a ring shape. The rotation transmission member 454 is formed in a cylindrical shape. The clamp load cell 80a and the rotation transmission member 454 are arranged coaxially with the reference axis L1.

  The rotation transmitting member 454 extends from the main body portion 56 toward the die structure 43, and the clamp shaft 453 is accommodated therein. The punch shaft 51 is accommodated in the internal space of the clamp shaft 453.

  The clamp shaft 453 has an outer screw formed on the outer peripheral portion. Further, the rotation transmission member 454 has an inner screw formed on the inner periphery. The clamp shaft 453 is supported by the rotation transmission member 454 by being screwed to the rotation transmission member 454. Further, the clamp shaft 453 is formed with a clamp engagement portion extending along the reference axis direction on the inner peripheral portion. The punch shaft 51 is formed with a punch engaging portion extending along the reference axis direction on the outer peripheral portion. The punch shaft 52 is accommodated in the internal space of the clamp shaft 53, and the clamp engaging portion engages with the punch engaging portion, whereby the rotation of the clamp shaft 53 is prevented.

  When the servo motor 55 for clamping rotationally drives the rotation transmitting member 454, the rotation transmitting member 454 transmits a rotational force to the clamp shaft 53. The clamp shaft 53 is displaced along the reference direction Z because angular displacement is prevented by the punch shaft 53. Even with such a configuration of the punch structure 441, it is possible to obtain the same effect as the striking device shown in FIG.

  The above-described embodiment of the present invention is an embodiment, and the configuration may be changed within the scope of the invention. For example, the number of members 2 and 3 is two, but may be three or more. Moreover, although the hammering apparatus 40 which joins a joining member with the punch rivet 1 was demonstrated as one Embodiment, if the apparatus which joins in the state which clamped the to-be-joined object 9, it can achieve the same effect. it can. For example, a friction stir welding apparatus and a resistance spot welding apparatus may be used.

  Each load cell 80a, 80b, 80c is used to detect each pressing force. However, the control means 73 determines each load based on the motor current values of the clamping servo motor 55 and the punch servo motor 60. You may ask for it. Thus, by obtaining each pressing force based on the motor current value of each servo motor, the load cell described above becomes unnecessary, and the structure can be simplified.

  Further, the pressing force for pressing the workpiece 9 by the clamp shaft 53 may not be constant, and may be changed according to the bonding processing state. Since the clamp shaft 53 can be displaced and moved independently of the punch shaft 52, the pressing state of the clamp shaft 53 can be easily changed according to the bonding processing state.

  The striking device 40 is an end effector provided at the tip of the robot arm 44, but may not be provided in the robot arm 44, and may be fixed at a predetermined position. That is, the joint device 101 may not include an articulated robot.

It is sectional drawing which simplifies and shows the striking device 40 which is one Embodiment of this invention. FIG. 3 is a cross-sectional view showing a part of the striking device 40 for explaining a method of joining the joining members 2 and 3 with the punch rivet 1. 2 is an enlarged perspective view showing a plurality of punch rivets 1. FIG. 4 is an enlarged cross-sectional view showing a punch structure 41. FIG. It is a perspective view which shows the load cell 80a for a clamp. It is sectional drawing which shows the load cell 80a for a clamp. It is a perspective view which shows the load cell 80b for punches. It is sectional drawing which shows the load cell 80b for punches. It is a perspective view which expands and shows die composition object 43. 4 is a plan view showing a die structure 43. FIG. It is a perspective view which shows the rivet filling apparatus 78. FIG. 1 is a side view showing a joining facility 100 including a striking device 40. FIG. 4 is a block diagram showing an electrical configuration of the striking device 40. FIG. 3 is a flowchart showing a procedure of main joining operations of the joining apparatus 101. 4 is a flowchart showing a procedure of a die contact operation of the bonding apparatus 101. It is a side view for demonstrating the procedure of die contact | abutting operation | movement of the joining apparatus 101. FIG. FIG. 3 is a front view showing the die 50 in a simplified manner. FIG. 18 is a cross-sectional view showing the die structure 43 as viewed from the S18-S18 cut line in FIG. 17. FIG. 3 is a front view showing the die 50 in a simplified manner. FIG. 20 is a cross-sectional view showing the die structure 43 as viewed from the section line S20-S20 in FIG. 19.

It is a figure for demonstrating the other calculating method. It is a figure for demonstrating the other calculating method. 4 is a flowchart showing a procedure of plate thickness measurement operation of the bonding apparatus 101. It is sectional drawing for showing the procedure of the plate | board thickness measurement operation | movement of the joining apparatus. It is a flowchart which shows the procedure of other plate | board thickness measurement operation | movement of this Embodiment. It is sectional drawing for showing the procedure of other plate | board thickness measurement operation | movement. It is a graph which shows the relationship between the pushing amount of the rivet 1, and the board thickness of the to-be-joined object 9. 4 is a flowchart showing a procedure of a rivet pushing amount determination operation of the joining apparatus 101. 6 is a side view for explaining deflection correction of a base 45 by a robot arm 44. FIG. 5 is a graph showing the relationship between the pressing force applied to the die structure 43 and the deflection of the base 45. 3 is a flowchart showing a procedure of a deflection amount correcting operation of the joining apparatus 101. It is a flowchart which shows the procedure of the clamp pushing load adjustment operation | movement of the joining apparatus 101. FIG. It is a flowchart which shows an example of joining operation | movement concretely. It is a flowchart which shows an example of joining operation | movement concretely. It is sectional drawing which shows the start state of joining operation | movement. It is sectional drawing which shows the state which die | dye 50 contact | abutted to the to-be-joined object. It is sectional drawing which shows the state which the clamp axis | shaft 53 contact | abutted to the to-be-joined object. It is sectional drawing which shows the state which the rivet 1 contact | abutted to the to-be-joined object. It is sectional drawing which shows the state where the rivet 1 was immersed in the to-be-joined object. It is sectional drawing which shows the striking device 40 in a 1st preparation state, respectively.

It is sectional drawing which shows the striking device 40 in a 2nd preparation state, respectively. It is a perspective view which shows the movement path | route of the clamp axis | shaft 53 in this invention. It is a perspective view which shows the movement path | route of the clamp axis | shaft 53 in a comparative example. It is sectional drawing which simplifies and shows the striking device 440 which is other embodiment of this invention. It is sectional drawing which shows a part of structure of the hitting apparatus 10 of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Punch side joining member 3 Die side joining member 9 To-be-joined object 40 Punching device 41 Punch structure 42 Punch drive means 43 Die structure 44 Robot arm 45 Base 50 Die 51 Punch 53 Clamp shaft 55 Clamp servo motor 60 Punch Servo motor 73 Control means 80a, 80b, 80c Load cell 84a, 84b, 84c Displacement sensor

Claims (7)

A support for supporting an object to be joined including a plurality of joining members;
A clamp body which is provided so as to be displaceable in a reference direction close to and away from the support body, and which clamps an object to be joined in cooperation with the support body;
A clamp driving means for driving the clamp body to move in a reference direction close to and away from the support; and
A processing means for bonding each bonding member of the object to be bonded sandwiched between the support and the clamp body under a set processing condition;
A pressing force detecting means for detecting the pressing force of the object to be joined by the clamp body;
And a control unit that controls the clamp driving unit so that the pressing force of the object to be joined by the clamp body becomes a predetermined value based on the detected pressing force. A measuring means for measuring the dimensions of the object to be joined;
The joining apparatus according to claim 1, wherein the control means sets processing conditions by the processing means based on the measurement result. The measuring means includes a clamp body reference position which is a position in the reference direction of the clamp body when the clamp body abuts on the support body with no pressing force or a small pressing force, and the clamp body presses the support body with a predetermined reference pressing force. A storage unit for storing a support body displacement amount that is a displacement amount of the support body in a reference direction when pressing;
A detection unit for detecting a clamp body pressing position, which is a position in the reference direction of the clamp body when the clamp body presses the object to be joined with the reference pressing force;
Based on the clamp body reference position, the support body displacement amount, and the clamp body pressing position, the distance from the support body to the clamp body when the clamp body presses the work piece with the reference pressing force is the dimension of the work piece. The joining apparatus according to claim 2, further comprising: a calculation unit that calculates the following. A support state detecting means for detecting a support state of the object to be joined by the support;
The control means controls the processing means based on the support state of the object to be joined by the support body so as to allow the joining process when the pressing force of the object to be joined by the clamp body is equal to or higher than a predetermined reference pressing force. The joining apparatus according to any one of claims 1 to 3. A base on which a support is provided;
A base driving means for displacing the base;
A deformation state detection means for detecting the deformation state of the base,
The joining apparatus according to claim 1, wherein the control means controls the base driving means based on a deformation state of the base. A base on which a support, a clamp body, a clamp driving means and a processing means are provided;
Further includes base drive means for driving the base to displace,
6. The joining apparatus according to claim 1, wherein the control means controls the base driving means and the clamp driving means so as to drive the clamp body while displacing the base. . Processing means
A holding part for holding the joining piece detachably;
The joining apparatus according to claim 1, further comprising a holding unit driving unit that drives the holding unit to move in a reference direction that approaches and separates from the workpiece.

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