JP2010012935A - Automatic tire assembling method and automatic tire assembling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic tire assembling method and an automatic tire assembling device capable of relatively easily assembling the tire even to a vehicle having a small clearance between the tire and a fender. <P>SOLUTION: In a tire positioning step (S6, S16 in Fig.14 (not shown)) and a nut fastening step (S8, S18 in Fig.14 (not shown), and S37, S46 in Fig.15 (not shown)), positions where a pair of grasp arms 62 grasp the tire W are restricted to an upper part and a lower part of the tire W. Thereby, the tire W can be relatively easily assembled even to a vehicle body 16 of an automobile having the small clearance 222 between the tire W and the fender 220. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic tire assembling method and an automatic tire assembling apparatus for automatically assembling a tire with respect to a hub bolt of a vehicle.

  In an automobile assembly line, an operation of automatically assembling a tire, which is one of heavy parts, to a car body using a robot is performed.

  A tire assembling apparatus applied to this type of work usually includes a tire gripping part for gripping a tire and a plurality of nut runners for tightening nuts on a hub bolt provided on the vehicle body side.

  For example, as disclosed in Patent Document 1, this type of tire assembling apparatus includes a plurality of nut runners that can arrange nuts corresponding to the number of hub bolts of a vehicle at predetermined circumferential intervals, respectively. A tire assembly mechanism that automatically assembles tires to the vehicle, a nut supply mechanism that supplies the nuts one by one in a vertical posture, and the nut that is fed from the nut supply mechanism are all arranged around the nut runner. And a nut arrangement mechanism for delivering the nuts to the nut runners while being arranged around the circumference.

JP 2000-210825 A

  In the tire assembling apparatus, the nut is fastened to the hub bolt while the tire is gripped by the tire gripping means for gripping the tire.

  Recently, it has been desired to reduce the clearance between the fender and the tire due to the relationship with the design of the vehicle.

  The present invention responds to this type of request, and provides an automatic tire assembling apparatus and an automatic tire assembling method capable of assembling a tire relatively easily even in a vehicle having a small clearance between a tire and a fender. For the purpose.

  An automatic tire assembling method according to the present invention comprises an automatic tire assembling apparatus comprising a tire transport mechanism having a pair of arms for gripping a tire, and a nut tightening mechanism for tightening a plurality of nuts to a plurality of hub bolts. The automatic tire assembly method includes: a tire gripping step of gripping the tire by the pair of arms; and a tire positioning for positioning the tire with respect to a tire assembly portion of a vehicle by the pair of arms. And a nut tightening step of tightening each of the plurality of nuts to each of the plurality of hub bolts by the nut tightening mechanism in a state where the tire is gripped by the pair of arms, and the tire positioning step; In the nut tightening step, the position at which the pair of arms grips the tire is set to the position of the tire. And limits parts and the lower part.

  According to the present invention, a tire can be assembled relatively easily even in a vehicle having a small clearance between the tire and the fender.

  That is, generally, when the tire is not in contact with the ground, the tire and the tire mounting portion are biased by the suspension, but are not subjected to a reaction force from the ground, and therefore are positioned below when the tire is in contact with the ground. For this reason, the clearance between the tire attachment portion (particularly the upper portion thereof) and the fender before attaching the tire is larger than the clearance after the tire is attached and grounded. According to the present invention, in the step of positioning the tire on the tire assembly portion (tire positioning step) and the step of tightening the nut on the hub bolt (nut tightening step), the position at which the pair of arms grips the tire is set at the upper portion of the tire. And limit to the bottom. As a result, when the tire is in contact with the ground, the clearance between the left and right and upper sides of the tire and the fender is small, and even in a vehicle in which it is difficult to grip the tire with any arm, the tire can be gripped in the clearance. Therefore, the tire can be assembled relatively easily.

  The upper portion of the tire includes the uppermost portion of the tire, and an imaginary axis passing through the center of the tire and the uppermost portion of the tire is set as the symmetry axis, and 360 ° is divided by the number of bolt holes of the tire. The lower portion of the tire includes the lowermost portion of the tire, the imaginary axis is the axis of symmetry, and 360 ° is divided by the number of bolt holes in the tire. The number of the bolt holes may be four or more.

  Thereby, the suitable restriction | limiting range which considered the relationship between the position where a pair of arms hold | grips a tire, and the bolt hole of a tire can be set.

  That is, in general, the plurality of bolt holes are arranged at equal angles on concentric circles. For this reason, the bolt hole located on the uppermost side with respect to the height direction of the vehicle always exists within a predetermined angle range on the concentric circle from the uppermost portion on the concentric circle. Since the angle between the bolt holes is an angle obtained by dividing 360 ° by the number of bolt holes, the predetermined angle is obtained by dividing the angle into two equal parts (an angle obtained by dividing 180 ° by the number of bolt holes). It becomes the value of. Accordingly, in order to match the positions (rotation angles) of the plurality of bolt holes with the hub bolts while restricting the position where the pair of arms grips the tire to the upper and lower portions of the tire, the pair of arms One of the tires includes the uppermost portion of the tire, and the imaginary axis connecting the center of the tire and the uppermost portion of the tire is the axis of symmetry and 360 ° is equal to an angle obtained by dividing the tire by the number of bolt holes. An angle obtained by gripping a portion corresponding to one central angle, the other of the pair of arms including the lowermost portion of the tire, the imaginary axis as the axis of symmetry, and 360 ° divided by the number of bolt holes of the tire A portion corresponding to the second central angle equal to may be gripped. As described above, by limiting the position where the pair of arms grips the tire as described above, a suitable limit range is set in consideration of the relationship between the position where the pair of arms grips the tire and the bolt hole of the tire. can do.

  The automatic tire assembly method further includes a bolt hole position information acquisition step of detecting a bolt hole of the tire and acquiring bolt hole position information, and the pair of arms gripping the uppermost part and the lowermost part of the tire. In the state, a tire alignment step of aligning the tire in front of the tire mounting portion of the vehicle, a hub bolt position information acquisition step of detecting the hub bolt and acquiring hub bolt position information, the plurality of bolt holes, A rotation angle calculation step of calculating a rotation angle of the tire for matching the positions of a plurality of hub bolts, and a tire rotation step of rotating the tire according to the calculated rotation angle, and calculating the rotation angle In the process, the rotation angle of the tire can be limited to a value obtained by dividing 180 ° by the number of the hub bolts.

  Thereby, after positioning a tire in front of a tire attaching part, rotation of a tire can be minimized. Therefore, the work efficiency for assembling the tire can be improved.

  A tire assembly apparatus according to the present invention includes a tire transport mechanism having a pair of arms for gripping a tire, and a nut tightening mechanism for tightening each of a plurality of nuts to each of a plurality of hub bolts. The tire is positioned with respect to the tire assembly portion of the vehicle by the arms, and the nuts are clamped to the hub bolts by the nut tightening mechanism in a state where the tire is gripped by the pair of arms. The positioning of the tire and the tightening of the nut restrict the positions where the pair of arms grips the tire to the upper and lower portions of the tire.

  According to the present invention, a tire can be assembled relatively easily even in a vehicle having a small clearance between the tire and the fender.

  That is, generally, when the tire is not in contact with the ground, the tire and the tire mounting portion are biased by the suspension, but are not subjected to a reaction force from the ground, and therefore are positioned below when the tire is in contact with the ground. For this reason, the clearance between the tire attachment portion (particularly the upper portion thereof) and the fender before attaching the tire is larger than the clearance after the tire is attached and grounded. According to this invention, in the step of contacting the tire with the tire assembly portion (tire contact step) and the step of tightening the nut on the hub bolt (nut tightening step), the position where the pair of arms grips the tire is Restrict to the top and bottom of As a result, when the tire is in contact with the ground, the clearance between the left and right and upper sides of the tire and the fender is small, and even in a vehicle in which it is difficult to grip the tire with any arm, the tire can be gripped in the clearance. Therefore, the tire can be assembled relatively easily.

  The upper portion of the tire includes the uppermost portion of the tire, and an imaginary axis passing through the center of the tire and the uppermost portion of the tire is set as the symmetry axis, and 360 ° is divided by the number of bolt holes of the tire. The lower portion of the tire includes the lowermost portion of the tire, the imaginary axis is the axis of symmetry, and 360 ° is divided by the number of bolt holes in the tire. The number of the bolt holes may be four or more.

  Thereby, the suitable restriction | limiting range which considered the relationship between the position where a pair of arms hold | grips a tire, and the bolt hole of a tire can be set.

  That is, in general, the plurality of bolt holes are arranged at equal angles on concentric circles. For this reason, the bolt hole located on the uppermost side with respect to the height direction of the vehicle always exists within a predetermined angle range on the concentric circle from the uppermost portion on the concentric circle. Since the angle between the bolt holes is an angle obtained by dividing 360 ° by the number of bolt holes, the predetermined angle is obtained by dividing the angle into two equal parts (an angle obtained by dividing 180 ° by the number of bolt holes). It becomes the value of. Accordingly, in order to match the positions (rotation angles) of the plurality of bolt holes with the hub bolts while restricting the position where the pair of arms grips the tire to the upper and lower portions of the tire, the pair of arms One of the tires includes the uppermost portion of the tire, and the imaginary axis connecting the center of the tire and the uppermost portion of the tire is the axis of symmetry and 360 ° is equal to an angle obtained by dividing the tire by the number of bolt holes. An angle obtained by gripping a portion corresponding to one central angle, the other of the pair of arms including the lowermost portion of the tire, the imaginary axis as the axis of symmetry, and 360 ° divided by the number of bolt holes of the tire A portion corresponding to the second central angle equal to may be gripped. As described above, by limiting the position where the pair of arms grips the tire as described above, a suitable limit range is set in consideration of the relationship between the position where the pair of arms grips the tire and the bolt hole of the tire. can do.

  According to the present invention, a tire can be assembled relatively easily even in a vehicle having a small clearance between the tire and the fender.

  That is, generally, when the tire is not in contact with the ground, the tire and the tire mounting portion are biased by the suspension, but are not subjected to a reaction force from the ground, and therefore are positioned below when the tire is in contact with the ground. For this reason, the clearance between the tire attachment portion (particularly the upper portion thereof) and the fender before attaching the tire is larger than the clearance after the tire is attached and grounded. According to this invention, in the step of contacting the tire with the tire assembly portion (tire contact step) and the step of tightening the nut on the hub bolt (nut tightening step), the position where the pair of arms grips the tire is Restrict to the top and bottom of As a result, when the tire is in contact with the ground, the clearance between the left and right and upper sides of the tire and the fender is small, and even in a vehicle in which it is difficult to grip the tire with any arm, the tire can be gripped in the clearance. Therefore, the tire can be assembled relatively easily.

  FIG. 1 is a perspective explanatory view of an assembly line 10 in which a pair of tire assembly devices 12 according to an embodiment of the present invention are arranged.

  The assembly line 10 includes the tire assembly device 12 and a conveyance path 14. The conveyance path 14 conveys the pitch to the tire assembly position with the automobile body (vehicle) 16 placed on the carriage 14a. That is, in the conveyance path 14, the first mounting portion 18a on the front wheel side of the vehicle body 16 and the second mounting portion 18b on the rear wheel side of the vehicle body 16 are sequentially arranged at the tire mounting work station. Thus, the automobile body 16 is intermittently conveyed.

  The tire assembly device 12 is disposed on both sides of the conveyance path 14 (only one side is shown in FIG. 1), and the tire W is automatically assembled to the hub bolt 20 of the automobile body 16 (see FIG. 2). The tire assembly device 12 includes a first work mechanism 22 and a second work mechanism 24.

  The first working mechanism 22 transports and positions the tire W carried by the tire loading conveyor 26 to the first mounting portion 18a or the second mounting portion 18b, and receives supply of a plurality of nuts 30 from the nut supply mechanism 28. The nut 30 is fastened to the hub bolt 20 by the rotational driving force transmitted from the second working mechanism 24.

  The nut supply mechanism 28 includes a nut stock portion 32 that accommodates the nut 30, and a nut that takes out a predetermined number (five or four) of the nuts 30 from the nut stock portion 32 and arranges them on the nut stand 34. A picking robot 36. At the tip of the arm of the nut picking robot 36, there is provided an openable / closable nut chuck portion 38 for taking out the nut 30 accommodated in the nut stock portion 32 and placing it on the nut stand 34.

  As shown in FIG. 1, the first working mechanism 22 includes a robot body 40, and a rotatable index base 46 is attached to a wrist portion 44 provided at the tip of an arm portion 42 of the robot body 40. As shown in FIGS. 3 and 4, the index table 46 includes a tire gripping mechanism 50 for gripping the tire W, a nut tightening mechanism 52 for tightening the nut 30 to the hub bolt 20 on which the tire W is disposed, and nut tightening. A lock mechanism 54 (see FIG. 9) for attaching / detaching a nut tightening unit 122 (described later) of the mechanism 52 is provided.

  Further, as shown in FIG. 1, two nut fastening unit stands 56 a and 56 b (hereinafter also referred to as “stands 56 a and 56 b”) are arranged in the vicinity of the first working mechanism 22. Of the two stands 56a and 56b, a nut fastening unit 122b different from the nut fastening unit 122a attached to the indexing base 46 is placed on the stand 56b. The nut tightening unit 122b is different from the nut tightening unit 122a in the arrangement of the nut tightening portion 126.

  As shown in FIGS. 3 and 4, the tire gripping mechanism 50 includes a linear guide 60 that is driven by a motor (not shown). The linear guide 60 has a drive shaft (not shown) therein, and when the drive shaft is driven and rotated by the motor, the two gripping arms 62 are displaced along the linear guide 60. The drive shaft is formed with screw threads that are screwed in opposite directions with respect to the center, and when the drive shaft rotates, the two gripping arms 62 move while centering in opposite directions. In this way, the tire W can be gripped and released by approaching or separating the two gripping arms 62.

  Before describing the nut tightening mechanism 52 and the lock mechanism 54 of the first working mechanism 22, the second working mechanism 24 will be described.

  As shown in FIG. 1, the second working mechanism 24 is provided with a wrist portion 74 at the tip of an arm portion 72 constituting the robot body 70. An index table 76 is rotatably mounted on the wrist 74. As shown in FIG. 5, the index base 76 includes a rotational driving force generator 78 that generates a rotational driving force for tightening the nut 30 to the hub bolt 20 by the first mounting portion 18 a and the second mounting portion 18 b, and the hub bolt 20. CCD cameras 80 and 82 (hereinafter also referred to as “cameras 80 and 82”) for taking images of the first attachment portion 18a and the second attachment portion 18b are mounted. Hereinafter, the CCD camera is also simply referred to as a camera.

  The rotational driving force generator 78 includes two motors 84 and two rotational driving force transmitters 86 that are connected to the motors 84 and transmit the rotational driving force generated by the motors 84.

  As shown in FIG. 6, the rotational driving force transmission portion 86 includes a first rod 90, a first connecting member 92, a second rod 94, a second connecting member 96, a cylindrical recess 98, and a coil spring 100.

  One end of the first rod 90 is connected to an output shaft (not shown) of the motor 84, and the other end is connected to the first connecting member 92. The first connecting member 92 has a hollow shape, and is interposed between the first cylindrical portion 102, the second cylindrical portion 104 having a smaller diameter than the first cylindrical portion 102, and the first cylindrical portion 102 and the second cylindrical portion 104. And a first tapered portion 106 formed. The first cylindrical portion 102 is threaded, and is screwed with the end of the first rod 90 that is also threaded. The second connecting member 96 has the same configuration as the first connecting member 92, and includes a third cylindrical portion 108, a fourth cylindrical portion 110 having a smaller diameter than the third cylindrical portion 108, the third cylindrical portion 108, and the fourth cylindrical portion 108. And a second tapered portion 112 formed between the cylindrical portion 110 and the second tapered portion 112. The third cylindrical portion 108 is threaded and is screwed into the end of the cylindrical recess 98 in which the thread is also formed.

  The second rod 94 includes a cylindrical portion 114, and a third tapered portion 116 and a fourth tapered portion 118 that are formed at both ends thereof and increase in diameter toward the end portion. The diameter of the cylindrical portion 114 of the second rod 94 is slightly smaller than the diameter of the first cylindrical portion 102 of the first connecting member 92 and the fourth cylindrical portion 110 of the second connecting member 96. The third taper portion 116 of the second rod 94 is accommodated in the first connecting member 92 (first taper portion 106) and has a diameter larger than that of the second cylindrical portion 104. The fourth taper portion 118 of the second rod 94 is accommodated in the second connecting member 96 (second taper portion 112) and has a diameter larger than that of the fourth cylindrical portion 110. The coil spring 100 covers the second rod 94 and is sandwiched between the first connecting member 92 and the second connecting member 96.

  Since the rotational driving force transmission part 86 is configured as described above, the rotational axis can be displaced (offset) as shown in FIG. That is, even if the rotation axis Y1 of the first connection member 92 and the rotation axis Y2 of the second connection member 96 are deviated (offset), the rotational driving force is transmitted from the first connection member 92 to the second connection member 96. can do. That is, a universal joint mechanism is formed by the first connecting member 92, the second rod 94 and the second connecting member 96. As a result, as will be described later, even if the arrangement of the nut tightening unit 122 changes in the first working mechanism 22, it is possible to transmit the rotational driving force from the second working mechanism 24 to the first working mechanism 22. Become.

  Returning to the description of the first working mechanism 22, as shown in FIGS. 3 and 4, the nut tightening mechanism 52 includes a mounting plate 120 fixed to the index base 46 and a nut that is detachable from the mounting plate 120. And a tightening unit 122a. The mounting plate 120 is provided with the two locking mechanisms 54 described above for fixing the nut tightening unit 122a to the mounting plate 120. In the present embodiment, the nut tightening unit 122a can be replaced according to the arrangement of the hub bolt 20 and the bolt hole Wa (that is, the type of the tire W), and the stand 56b includes a replacement nut tightening unit 122b. Is arranged.

  As shown in FIG. 2, the mounting plate 120 is provided with a plurality of opening guide portions 124 to which the rotational driving force transmission portion 86 of the second working mechanism 24 is coupled.

  As shown in FIGS. 3 and 4, the nut tightening unit 122 a has five nut tightening portions 126. The number of nut tightening portions 126 is the same as the number of hub bolts 20 and bolt holes Wa.

  As shown in FIG. 8, each nut tightening portion 126 includes a third rod 128, a bearing 130, a wrench portion 132, and a coil spring 134.

  The end portion 128 a of the third rod 128 is disposed in the opening guide portion 124 of the mounting plate 120. The end 128a has a tapered tip. The end 128 a is connected to the cylindrical recess 98 of the rotational driving force transmitting portion 86 of the second working mechanism 24, so that the rotational driving force is transmitted from the second working mechanism 24 to the third rod 128. As a result, the third rod 128 rotates while being supported by the bearing 130. Two columnar protrusions 136 are formed on the third rod 128, and the rotational driving force is transmitted from the third rod 128 to the wrench 132 via the protrusions 136.

  The wrench part 132 is formed with a hole part 138 for accommodating each protrusion part 136. The hole 138 is formed in the longitudinal direction (axial direction) of the nut tightening unit 122, and the width thereof is slightly larger than the diameter of the protrusion 136. Therefore, the protrusion 136 can be displaced in the axial direction of the nut tightening unit 122 in the hole 138. The wrench portion 132 is formed with a recess 140 that holds the nut 30. The cross-sectional shape of the recess 140 is substantially equal to the cross-sectional shape of the nut 30. For this reason, when the recessed part 140 rotates, the nut 30 also rotates.

  The coil spring 134 is sandwiched between the third rod 128 and the wrench portion 132. In the third rod 128, the axial displacement of the nut tightening unit 122a is restricted. On the other hand, the wrench portion 132 can be displaced in the axial direction as far as the projection 136 can be displaced in the hole 138. Accordingly, the coil spring 134 biases the wrench portion 132 in a direction away from the third rod 128. Therefore, as the wrench portion 132 rotates, the wrench portion 132 is also separated from the third rod 128 as the nut 30 is tightened to the hub bolt 20. Thereby, the nut 30 can be tightened to a desired position with respect to the hub bolt 20.

  Next, the lock mechanism 54 and the stands 56a and 56b of the first working mechanism 22 will be described with reference to FIGS. As described above, the lock mechanism 54 fixes the nut tightening unit 122a to the mounting plate 120, and the nut tightening unit 122a can be detached from the mounting plate 120 by releasing the fixing by the lock mechanism 54.

  The locking mechanism 54 includes a stopper 142, a switching lever 144, and a link member 146 (only one locking mechanism 54 is shown in FIGS. 10A and 10B). The stopper 142 can selectively press the nut tightening unit 122a. When the stopper 142 presses the nut tightening unit 122a, the nut tightening unit 122a is fixed to the mounting plate 120. When the stopper 142 does not press the nut tightening unit 122a, the nut tightening unit 122 can be removed from the mounting plate 120. The switching lever 144 switches the pressing state of the stopper 142 according to the position. The link member 146 cooperates with the switching lever 144 to hold the pressed state or the non-pressed state of the nut tightening unit 122a by the stopper 142.

  Specifically, the switching lever 144 has a roller 148 disposed at one end thereof and a cam portion 150 formed at the other end thereof, and the switching lever 144 is bent at substantially the center thereof. The switching lever 144 is supported by the first support shaft A1 so as to be turnable. In addition, one end of the link member 146 is rotatably supported by the second support shaft A2 formed in the cam portion 150. At the other end of the link member 146, a bending member 152 that supports the stopper 142 is supported by the third support shaft A3 so as to be rotatable. The bending member 152 is also supported by the fourth support shaft A4 so as to be able to turn.

  FIG. 11 is a perspective view of the stand 56a that does not hold the nut tightening units 122a and 122b. As shown in FIG. 11, the stand 56 a is provided at the base 156, the substantially U-shaped holding plate 158, the two positioning pins 160, the two cylinders 162, and the distal ends of the cylinders 162. A substantially L-shaped engagement member 164 having a 164a and a vertical portion 164b, and a first support member 166 fixed to the second support member 168 that supports the engagement member 164 so as to be pivotable about the support shaft B1. With. For this reason, when the pressing portion 170 of the cylinder 162 rises, the horizontal portion 164a and the vertical portion 164b pivot around the support shaft B1.

  Next, a case where the nut tightening units 122a and 122b are replaced (a case where the nut tightening unit 122a is placed on the stand 56a) will be described with reference to FIG. The case where the nut tightening units 122a and 122b are replaced is a case where the type of the vehicle to which the tire W is attached is changed and the arrangement of the hub bolt 20 and the bolt hole Wa (FIG. 1) is changed accordingly.

  When replacing the nut tightening unit 122a and the nut tightening unit 122b, the nut tightening unit 122a currently mounted on the first working mechanism 22 is removed from the mounting plate 120 and placed on the stand 56a. Specifically, the arm portion 42 of the first working mechanism 22 is displaced, and the nut tightening unit 122a is positioned directly above the stand 56a. Then, the nut tightening unit 122a is lowered in the vertical direction, and the positioning hole 172 of the nut tightening unit 122a and the positioning pin 160 are engaged. Thereby, the position of the nut fastening unit 122a can be stabilized.

  When the roller 148 of the lock mechanism 54 comes into contact with the horizontal portion 164a of the engaging member 164 of the stand 56, the roller 148 is displaced upward by the weight of the nut tightening mechanism 52 (see FIG. 10A). As a result, the stopper 142 changes from a pressed state to a non-pressed state, and the nut tightening unit 122a can be removed from the mounting plate 120.

  In this state, when the arm portion 42 of the first working mechanism 22 moves upward, the nut tightening unit 122a is left mounted on the stand 56a, and the nut tightening unit 122a is attached to the mounting plate 120. It will be in the state which is not done.

  Then, this time, the arm portion 42 is moved to the stand 56 b on which another nut tightening unit 122 b is placed, and the positioning pin 160 is engaged with the mounting plate 120. In a state where the mounting plate 120 is in contact with the nut tightening unit 122b, the cylinder 162 is operated, and the horizontal portion 164a and the vertical portion 164b of the engaging member 164 are turned around the support shaft B1. Accordingly, the vertical portion 164 b displaces the roller 148 downward, and the nut tightening unit 122 b is fixed to the mounting plate 120 by the stopper 142. Then, the tire W is attached using the new nut tightening unit 122b. As described above, the nut tightening unit 122a and the nut tightening unit 122b differ in the arrangement of the nut tightening portion 126. That is, the diameter of the concentric circle formed by the nut tightening portion 126 is different. In addition, both may differ in the point from which the magnitude | size of the nut 30 which the nut fastening part 126 hold | maintains, and the number of the nut fastening parts 126 differ.

  FIG. 13 shows a control system of the tire assembly device 12. As shown in FIG. 13, the cameras 80 and 82 of the second working mechanism 24 output image information of the first attachment portion 18 a and the second attachment portion 18 b to the first image processing apparatus 200.

  The first image processing apparatus 200 further receives image information of the tire W (bolt hole Wa of the tire W) from a camera 202 (bolt hole detection sensor) for photographing the tire W disposed on the tire loading conveyor 26. Entered.

  In the vicinity of the nut picking robot 36 of the nut supply mechanism 28, a camera 204 that captures an image of the nuts 30 arranged on the nut stand 34 is fixed. Image information of the nut 30 photographed by the camera 204 is input to the second image processing device 206.

  The first image processing apparatus 200 is connected to a calculation unit 208, where the position of the hub bolt 20 of the first mounting portion 18a, the position of the hub bolt 20 of the second mounting portion 18b, and the tire on the tire loading conveyor 26 are connected. The relative position of the W bolt hole Wa is calculated and output to the main controller (control mechanism) 210. The second image processing device 206 is connected to the calculation unit 208, and the image information of the nut 30 photographed by the camera 204 is calculated by the calculation unit 208 and output to the main control device 210.

  The main control device 210 calculates the calculation information input from the calculation unit 208, the position information of the first work mechanism 22 (position information of the arm part 42, the position information of the gripping arm 62, etc.) and the position information of the second work mechanism 24. Based on (position information of the arm part 72, position information of the rotational driving force transmission part 86, etc.), the operation of the first work mechanism 22 is controlled, and the operation of the second work mechanism 24 and the nut supply mechanism 28 is also controlled. .

  The tire assembling apparatus 12 according to the present embodiment is configured as described above. Next, referring to the flowcharts shown in FIGS. 14 and 15 and the timing chart shown in FIG. The operation of will be described. FIG. 14 shows an operation centered on the first work mechanism 22, and FIG. 15 shows an operation centered on the second work mechanism 24. FIG. 16 shows the relevance of the operations of the first working mechanism 22, the second working mechanism 24, and the nut supply mechanism 28.

  First, the operation centering on the first work mechanism 22 will be described. In step S1 of FIG. 14, the first work mechanism 22 uses five nuts 30 arranged on the nut stand 34 as five wrenches. It is held by the part 132.

  In subsequent step S2, the tire gripping mechanism 50 grips the tire W on the tire loading conveyor 26. Specifically, as shown in FIGS. 3 and 4, the linear guide 60 is driven by a motor (not shown) with the tire W positioned between the two gripping arms 62 of the tire gripping mechanism 50. As a result, the two gripping arms 62 move in a direction approaching each other, and the outer peripheral surface (ground contact surface) of the tire W is gripped.

  When gripping the tire W, the two gripping arms 62 have a position (rotation phase) of each bolt hole Wa of the tire W and a position (rotation phase) of each nut tightening portion 126 of the nut tightening mechanism 52. Positioned to match. As a result, each nut 30 is arranged corresponding to each bolt hole Wa of the tire W.

  The positioning is performed as follows, for example. That is, main controller 210 detects the position of each bolt hole Wa of tire W and the position of each nut tightening portion 126. The position of each bolt hole Wa is detected based on the image information of the camera 202. In addition, since the relative positions of the two gripping arms 62 and the nut tightening portions 126 are fixed, the position of each nut tightening portion 126 supports the position of the two gripping arms 62 or the gripping arms 62. It detects based on the position of the index stand 46 to be performed. Then, the gripping arm 62 is positioned by moving the index base 46 to a position where the position of each bolt hole Wa and the position of each nut tightening portion 126 coincide. Thus, since the grip position of the grip arm 62 and each bolt hole Wa of the tire W are associated with each other, the position of each bolt hole Wa can be determined by grasping the position of the grip arm 62 and the position of the index base 46. You can also know.

  In step S <b> 3, the first working mechanism 22 that holds the nut 30 and the tire W moves to the attachment standby position under the turning action of the robot body 40. In that case, the vehicle body 16 has the first mounting portion 18a on the front wheel side disposed at the tire mounting work station. Further, at the attachment standby position, the two grip arms 62 are arranged so as to be aligned in the vertical direction.

  That is, the main controller 210 determines that the position at which one of the gripping arms 62 grips the tire W is based on the position information of the arm portion 42, the position information of the gripping arm 62, etc. (the position Pu1 in FIG. 17). And the position where the other gripping arm 62 grips the tire W is the lowermost part of the tire W (the position corresponding to the position Pl1 in FIG. 17). The other gripping arm 62 is arranged so as to be.

  Then, in a state where the first work mechanism 22 is disposed at the attachment standby position, the cameras 80 and 82 of the second work mechanism 24 acquire image information of the first attachment portion 18a (hereinafter also referred to as “front wheel image information”). When the first image processing device 200 calculates the correction amount for the reference position of each hub bolt 20 based on the front wheel image information (step S4: YES), the main control device 210 grips the tire W in step S5. An amount (hereinafter also referred to as “arm displacement amount”) for displacing the gripping arm 62 is calculated. The arm displacement amount includes the displacement amount of the grip arm 62 in the X-axis direction, the Y-axis direction, and the Z-axis direction (see FIG. 1) and the rotation angle of the tire W. The rotation angle of the tire W is such that when the tire W is arranged in front of the hub bolt 20 and the center O of the tire and the center of the concentric circle formed by the hub bolt 20 coincide with the Y direction in FIG. Is the angle at which the tire W is rotated by the gripping arm 62 in order to match the position (rotation phase) of the bolt hole Wa, and is calculated as the angle at which the tire W is rotated with reference to the center O of the tire W.

  In the present embodiment, the main controller 210 limits the rotation angle of the tire W to ± 36 ° (see FIG. 17). This is due to the following reason. That is, the bolt holes Wa are arranged at equiangular angles on a concentric circle. For this reason, the bolt hole Wa positioned on the uppermost side with respect to the vehicle height direction (Z direction in FIG. 1) is always within a predetermined angle range of the positive and negative on the concentric circle from the uppermost portion on the concentric circle. Exists. Since the angle between the bolt holes Wa is an angle obtained by dividing 360 ° by the number of bolt holes Wa, the predetermined angle is an angle obtained by further dividing the angle into two (180 ° divided by the number of bolt holes Wa). ). In the present embodiment, since the number of bolt holes Wa is five, the predetermined angle is ± 36 °. Therefore, even if the rotation angle of the tire W is limited to ± 36 ° at the maximum, the position (rotation phase) of the hub bolt 20 and the bolt hole Wa can always be matched.

  As described above, in order to match the position (rotation phase) of the hub bolt 20 and the bolt hole Wa while limiting the rotation angle of the tire W to ± 36 °, the following calculation is performed. That is, the position (rotation phase) of the hub bolt 20 is determined based on image information from the cameras 80 and 82 of the second working mechanism 24. For example, a virtual axis Z1 extending in the height direction (Z direction in FIG. 1) from the center of the concentric circle of the hub bolt 20 is set. Next, the highest one of the five hub bolts 20 is detected, and the position (rotation) of the hub bolt 20 is determined according to which side the hub bolt 20 is located with respect to the virtual axis Z1 and the distance of the hub bolt 20 with respect to the virtual axis Z1. Phase).

  Further, the position (rotational phase) of the bolt hole Wa can be specified by the relative position between the gripping arm 62 and the bolt hole Wa calculated in step S2.

  In subsequent step S6, main controller 210 displaces gripping arm 62 based on the amount of arm displacement calculated in step S5, and positions tire W on first mounting portion 18a. Thereby, the tire W is arranged at a position waiting for tightening of the nut 30.

  As described above, in the present embodiment, the grip arm 62 grips the uppermost and lowermost portions of the tire W in the mounting standby position, and restricts the rotation angle of the tire W to ± 36 °. Yes. For this reason, as shown in FIG. 17, the gripping arm 62 that grips the upper portion of the tire W has a virtual axis Z2 that passes through the center O of the tire W and the uppermost portion Pu1 of the tire W (the virtual axis Z1 described above). And a portion of the contact surface of the tire W corresponding to the first central angle α1 of 72 °. Similarly, the gripping arm 62 that grips the lower part of the tire W grips any part of the contact surface of the tire W with the virtual axis Z2 as the axis of symmetry and corresponding to the second central angle α2 of 72 °. To do. In other words, in the present embodiment, the range of the ground contact surface that can be gripped by the gripping arm 62 under the above limitation is the upper and lower portions of the tire W.

  As a result, the gripping arm 62 that grips the upper portion of the tire W is displaced between the fender 220 of the automobile body 16 and the clearance 222 between the tires W.

  In order to limit the position where the grip arm 62 grips as described above, the grip arm 62 does not have to grip the uppermost part and the lowermost part of the tire W at the attachment standby position. For example, by rotating the tire W when positioning the tire W with respect to the automobile body 16, the position where the grip arm 62 grips the tire W can be limited to the above range.

  In addition, the limitation on the gripping position as described above is not very effective when the number of bolt holes Wa or hub bolts 20 is small (specifically, when the number is three or less). Therefore, it is preferable to perform the restriction when the number of bolt holes Wa or hub bolts 20 is four or more.

  When the positioning of the tire W is completed, the main controller 210 connects the second work mechanism 24 to the first work mechanism 22 in step S7. That is, the cylindrical concave portion 98 of the rotational driving force generating portion 78 of the second working mechanism 24 is engaged with the third rod 128 of the nut tightening mechanism 52 of the first working mechanism 22. In step S <b> 8, the rotational driving force is transmitted from the second working mechanism 24 to the first working mechanism 22, and the nut 30 is fastened to the hub bolt 20. Specifically, the rotational driving force is transmitted from the rotational driving force generator 78 to the nut tightening mechanism 52. As a result, the wrench portion 132 of the first working mechanism 22 rotates, whereby the nut 30 held by the wrench portion 132 is fastened to the hub bolt 20. During the tightening, the position of the gripping arm 62 is fixed and maintained within the limit range described above.

  After the tire W is assembled as a front wheel to the first mounting portion 18a, when the second work mechanism 24 is moved out of interference (step S9: YES), the robot body 40 of the first work mechanism 22 is moved to step S10. The first mounting portion 18a is moved away from the first mounting portion 18a to the original position on the nut stand 34 side.

  The processing for the first mounting portion 18a described above is performed similarly for the second mounting portion 18b. That is, steps S11 to S20 similar to steps S1 to S10 are performed for the second attachment portion 18b. In addition, between steps S10 to S14, the automobile body 16 is intermittently conveyed in the X direction in FIG. For this reason, as for the vehicle body 16, the 2nd attachment part 18b which is the rear-wheel side is arrange | positioned at a tire attachment work station.

  When the attachment of the tire W to the second attachment portion 18b is completed, the same processing is performed for another automobile body 16.

  Next, the operation centering on the second working mechanism 24 will be described below with reference to FIG.

  In the second work mechanism 24, cameras 80 and 82 are disposed corresponding to the tire mounting work station under the action of the robot body 70. When the first mounting portion 18a, which is the front wheel side of the automobile body 16, is disposed at the tire mounting work station (step S31: YES), the second working mechanism 24 moves the cameras 80 and 82 in step S32. Then, the image information of the front wheel hub bolt 20 of the first mounting portion 18a is read.

  The read image information of the cameras 80 and 82 is output to the first image processing apparatus 200. In step S33, the first image processing apparatus 200 calculates a correction amount with respect to the reference position of each hub bolt 20. For example, assuming a virtual axis Z1 extending in the height direction of the vehicle body 16 from the center of the concentric circles of the five hub bolts 20, the hub bolt 20 at the highest position among the five hub bolts 20 is on the virtual axis Z1. The case can be used as a reference position. The correction amount is output from the calculation unit 208 to the main controller 210.

  In step S34, the second working mechanism 24 moves to a position where it does not interfere with the work by the first working mechanism 22 in the first mounting portion 18a. When the first work mechanism 22 completes the positioning of the tire W (step S35: YES), the second work mechanism 24 is coupled to the first work mechanism 22 in step S36. That is, in the first attachment portion 18 a, the rotational driving force transmission portion 86 of the second working mechanism 24 is connected to the nut tightening portion 126 of the first working mechanism 22.

  In step S <b> 37, the second working mechanism 24 generates a rotational driving force by the motor 84 and transmits this rotational driving force from the rotational driving force transmission unit 86 to the nut tightening unit 126. Thereby, the nut 30 is fastened to the hub bolt 20 and the tire W is attached to the first attachment portion 18a. Note that the number of the rotational driving force transmission portions 86 is two, while the number of the nut tightening portions 126 is five. For this reason, the rotation driving force transmission part 86 and the nut tightening part 126 are connected a plurality of times (the nut 30 is fastened to the hub bolt 20 in the order of two, two, and one).

  After the tire W is attached to the first attachment portion 18a, in step S38, the second working mechanism 24 moves out of interference. Next, in step S39, the second working mechanism 24 moves to the rear wheel hub bolt detection position. In step S40, the second working mechanism 24 determines whether the vehicle body 16 has been transported along the transport path 14 by a half pitch. Determine whether.

  If it is determined that the vehicle body 16 has been transported by a half pitch (step S40: YES), that is, if it is determined that the second mounting portion 18b on the rear wheel side is disposed at the tire mounting work station, steps S32 to S38. Steps S41 to S47 similar to the above are performed for the second mounting portion 18b. In step S48, the second working mechanism 24 moves to the front wheel hub bolt position.

  When the attachment of the tire W to the second attachment portion 18b is completed, the same processing is performed on another automobile body 16.

  As shown in FIG. 16, the nut supply mechanism 28 is configured to transfer and align the front wheel nut 30 from the nut stock portion 32 to the nut stand 34 via the nut chuck portion 38 and the rear wheel nut. 30 conveyance and alignment operations are repeated.

  Further, as described above, in the assembly line 10, the tire assembly devices 12 are arranged on both sides of the automobile body 16, and operations similar to the above are performed substantially simultaneously.

  Furthermore, the replacement of the nut tightening units 122a and 122b is performed according to the position of the hub bolt 20 and the bolt hole Wa. For example, the main controller 210 determines whether or not the position of the bolt hole Wa based on the image information obtained by the first image processing apparatus 200 is different from the position of the nut tightening units 122a and 122b currently used. If different, the nut tightening units 122a and 122b can be exchanged from one to the other.

  As described above, according to the present embodiment, in the tire positioning step (S6, S16 in FIG. 14) and the nut tightening step (S8, S18 in FIG. 14, S37, S46 in FIG. 15), a pair of gripping arms 62 is provided. The position where the tire grips the tire W is limited to the upper part and the lower part of the tire W. Thereby, the tire W can be assembled relatively easily even in the automobile body 16 having a small clearance 222 between the tire W and the fender 220.

  That is, in general, when the tire W is not in contact with the ground, the tire W and the first mounting portion 18a and the second mounting portion 18b are urged by a suspension (not shown), but do not receive a reaction force from the ground. It is positioned below when W is grounded. Therefore, the clearance 222 between the first mounting portion 18a and the second mounting portion 18b (particularly the upper portion) before the tire W is mounted and the fender 220 is the clearance 222 after the tire W is mounted and grounded. Bigger than. According to the present embodiment, the pair of gripping arms 62 grips the tire W in the step of positioning the tire W on the tire assembly portion (tire positioning step) and the step of tightening the nut 30 on the hub bolt 20 (nut tightening step). The position to be limited is limited to the upper part and the lower part of the tire W. Thus, in a state where the tire W is in contact with the ground, the clearance 222 between the left and right and upper sides of the tire W and the fender 220 is small, and even in a vehicle in which it is difficult to grip the tire W by any gripping arm 62, the tire W Therefore, the tire W can be assembled relatively easily.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the description in this specification.

It is a perspective explanatory view of an assembly line in which a tire assembly device according to an embodiment of the present invention is arranged. It is a perspective explanatory view showing the state where the tire is assembled by the tire assembling apparatus. It is principal part perspective explanatory drawing of the 1st working mechanism which comprises the said tire assembly apparatus. It is principal part front explanatory drawing of a said 1st working mechanism. It is principal part perspective explanatory drawing of the 2nd working mechanism which comprises the said tire assembly apparatus. It is principal part cross-sectional explanatory drawing of the rotational drive force transmission part which comprises the said 2nd working mechanism. It is principal part cross-sectional explanatory drawing which shows an example of the state which the said rotational driving force transmission part is act | operating. FIG. 5 is a partial cross-sectional explanatory view of a main part of a nut tightening unit and the rotational driving force transmission unit constituting the first working mechanism. It is principal part explanatory drawing of the lock mechanism which comprises the said 1st working mechanism, and the said nut fastening unit. FIG. 10A is an explanatory front view of the lock mechanism in a state where the nut tightening unit is not fixed. FIG. 10B is an explanatory front view of a state in which the lock mechanism fixes the nut tightening unit. It is a perspective explanatory view of a nut tightening unit stand that constitutes the tire assembling apparatus. It is front explanatory drawing which shows the state which replaces | exchanges the said nut fastening unit using the said nut fastening unit stand. It is a block diagram of the control system of the said tire assembly apparatus. It is a flowchart explaining the operation | movement centering on a said 1st working mechanism. It is a flowchart explaining the operation | movement centering on a said 2nd working mechanism. It is a timing chart which the said tire assembly apparatus assembles | assembles a tire on a motor vehicle body. It is explanatory drawing which shows the positional relationship of the holding | grip arm which comprises the said 1st working mechanism, a tire, and a fender.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Tire assembly apparatus 16 ... Automobile body 18a ... 1st attaching part (tire attaching part) 18b ... 2nd attaching part (tire attaching part)
20 ... hub bolt 22 ... first working mechanism (tire transport mechanism)
24 ... Second working mechanism 30 ... Nut 50 ... Tire gripping mechanism 52 ... Nut tightening mechanism 62 ... Grip arm 80, 82, 202, 204 ... CCD camera O ... Center of tire W ... Tire Wa ... Bolt hole Z1, Z2 ... Virtual axis α1 ... first central angle α2 ... second central angle

Claims (5)

An automatic tire assembling method using a tire assembling apparatus comprising a tire conveying mechanism having a pair of arms for gripping a tire and a nut tightening mechanism for tightening each of a plurality of nuts to each of a plurality of hub bolts,
The automatic tire assembly method is:
A tire gripping step of gripping the tire by the pair of arms;
A tire positioning step of positioning the tire with respect to the tire assembly portion of the vehicle by the pair of arms;
A nut tightening step of tightening each of the plurality of nuts to each of the plurality of hub bolts by the nut tightening mechanism in a state where the tire is gripped by the pair of arms;
Have
In the tire positioning step and the nut tightening step, a position where the pair of arms grips the tire is limited to an upper portion and a lower portion of the tire. In the automatic tire assembling method according to claim 1,
The upper portion of the tire includes the uppermost portion of the tire, and an imaginary axis passing through the center of the tire and the uppermost portion of the tire is set as the symmetry axis, and 360 ° is divided by the number of bolt holes of the tire. A portion corresponding to a first central angle equal to the angle;
The lower portion of the tire includes a lowermost portion of the tire and is a portion corresponding to a second central angle equal to an angle obtained by dividing the virtual axis by the number of bolt holes of the tire with the imaginary axis as the axis of symmetry. ,
The number of the bolt holes is four or more. An automatic tire assembling method, wherein: In the automatic tire assembling method according to claim 1 or 2,
The automatic tire assembly method further includes:
A bolt hole position information acquisition step of detecting the bolt hole of the tire and acquiring bolt hole position information;
A tire alignment step of aligning the tire in front of a tire mounting portion of the vehicle with the pair of arms gripping the uppermost portion and the lowermost portion of the tire;
A hub bolt position information acquisition step of detecting the hub bolt and acquiring hub bolt position information;
A rotation angle calculating step of calculating a rotation angle of the tire for matching the positions of the plurality of bolt holes and the plurality of hub bolts;
A tire rotation step of rotating the tire according to the calculated rotation angle;
Have
In the rotation angle calculation step, the rotation angle of the tire is limited to a value obtained by dividing 180 ° by the number of hub bolts. A tire transport mechanism having a pair of arms for gripping the tire;
A nut tightening mechanism for tightening each of the plurality of nuts to each of the plurality of hub bolts;
A tire assembly apparatus comprising:
The tire is positioned with respect to the tire assembly portion of the vehicle by the pair of arms,
In a state where the tire is gripped by the pair of arms, each of the plurality of nuts is tightened to each of the plurality of hub bolts by the nut tightening mechanism,
An automatic tire assembling apparatus, wherein a position at which the pair of arms grips the tire is limited to an upper portion and a lower portion of the tire when the tire is positioned and the nut is tightened. In the automatic tire assembling apparatus according to claim 4,
The upper portion of the tire includes the uppermost portion of the tire, and an imaginary axis passing through the center of the tire and the uppermost portion of the tire is set as the symmetry axis, and 360 ° is divided by the number of bolt holes of the tire. A portion corresponding to a first central angle equal to the angle;
The lower portion of the tire includes a lowermost portion of the tire and is a portion corresponding to a second central angle equal to an angle obtained by dividing the virtual axis by the number of bolt holes of the tire with the imaginary axis as the axis of symmetry. ,
The automatic tire assembling apparatus, wherein the number of the bolt holes is four or more.

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