JP4645191B2 - Laser type coordinate measuring machine - Google Patents

Description

  The present invention relates to a laser type three-dimensional measuring machine that measures a three-dimensional position of a fixed gun tip of a welding gun.

  2. Description of the Related Art Conventionally, a welding robot for welding a vehicle body includes a robot main body 102 installed on a floor F at a welding site and a welding gun 103 rotatably attached to the robot main body 102 as in the welding robot 101 shown in FIG. ing.

  The welding gun 103 includes a U-shaped arm 104 rotatably attached to the robot body 102, a fixed-side gun 105 provided on one end side of the arm 104 and fixed in position, and the other end side of the arm 104. The movable side gun 106 is provided opposite to the fixed side gun 105 and moves forward and backward with respect to the fixed side gun 105.

  As shown in FIG. 5 (only the fixed-side gun 105 is shown), both the guns 105 and 106 are composed of a gun main body 107 attached to the arm 104 and a gun tip 108 attached to the tip of the gun main body 107. The tip 111 of the gun tip 108 constitutes the tip of both guns 105 and 106.

  Inside the gun body 107, a cooling water return channel 109 is formed up to the tip along the gun body 107, and a cooling water supply pipe is provided in the cooling water return channel 109 along the cooling water return channel 109. 110 is arranged.

  On the other hand, when creating teaching data of the welding robot 101, three-dimensional position data of the tip 111 of the gun tip 108 of the normal fixed side gun 105 (hereinafter referred to as the fixed side gun tip 108) is necessary. The original position is measured by a laser type coordinate measuring machine. As this laser type coordinate measuring machine, a laser type coordinate measuring machine 201 as shown in FIG. 4 is known.

  The laser type three-dimensional measuring machine 201 includes a laser measuring machine main body 202 and a control device 203 connected to the laser measuring machine main body 202 via a cable.

  In order to measure the position of the tip 111 of the fixed-side guntip 108, the control device 203 controls the laser measuring machine main body 202 to irradiate the tip 111 of the guntip 108 from the laser measuring machine main body 202 and reflect from the tip 111. The detected laser is detected again by the laser measuring machine main body 202, and the detection signal is output to the control device 203.

  Based on this detection signal, the control device 203 measures the time from laser irradiation to detection, calculates the distance from the laser measuring machine body 202 to the tip 111 of the fixed-side guntip 108, and measures the irradiation angle to the tip 111. From this distance and angle, the position of the gun tip tip 111 is measured by a trigonometric function.

  However, in such a laser type three-dimensional measuring machine 201, when the welding gun 103 is inclined, the fixed-side gun 105 is also inclined, so that the laser is accurately applied to the tip 111 of the gun tip 108. It was difficult to measure the position of the tip 111 easily.

  In order to solve this problem, a three-dimensional position of the tip 111 of the gun tip 108 is obtained by attaching an attachment having a reflector that reflects the laser instead of the gun tip 108 to the fixed gun body 107 and irradiating the center of the reflector with the laser. It is also conceivable to measure

  However, in this case, it is necessary to significantly modify the fixed-side gun 105 including the cooling water return channel 109 and the cooling water supply pipe 110 so that both the attachment and the gun tip 108 can be attached and detached. Therefore, in addition to the manufacturing cost of the attachment, the remodeling cost of the fixed side gun 105 is also required, so that the cost for measuring the position of the fixed side gun tip 111 is greatly increased.

  The present invention has been made in view of such a conventional problem, and is capable of easily measuring the position of the fixed-side gun tip while suppressing a significant increase in cost even when the welding gun is inclined. The purpose is to provide a measuring machine.

In order to solve the above-mentioned problem, in the laser type three-dimensional measuring machine according to claim 1 of the present invention, the measuring machine main body and an attachment that is externally fitted to a fixed gun tip of a welding gun are attached, An outer fitting portion that is externally fitted to the fixed-side guntip, a reflector mounting portion that extends forward from the outer fitting portion along the extending direction of the fixed-side guntip, and the reflector mounting portion that is on the fixed side A pair of reflectors that are located at the tip of the guntip and are spaced apart along the extending direction of the fixed-side guntip and reflect the laser;
Both reflectors pass along an extension line whose center extends from the tip of the fixed-side guntip to the front along the extending direction of the fixed-side guntip in a state where the outer fitting portion is externally fitted to the fixed-side guntip. The mounting position on the reflector mounting portion is set so that the distance from the tip of the fixed guntip to the center of the reflector closer to the fixed guntip is the same as the distance between the centers of both reflectors. On the other hand, the measuring machine main body irradiates the centers of the two reflectors with lasers and detects the laser beams reflected from the centers of the two reflectors to detect the three-dimensional positions (Rax, Rby) of the centers of the two reflectors. , Rcz), (Rdx, Rdy, Rfx) measuring means, and far from the fixed-side guntip The three-dimensional position (Rdx, Rey, Rfz) at the center of both reflectors is reduced by subtracting the three-dimensional position (Rdx, Rey, Rfz) at the center of the reflector closer to the fixed guntip from the three-dimensional position (Rax, Rby, Rcz) at the center of the two reflectors. From the first calculation means for calculating the position difference (Rax-Rdx, Rby-Rey, Rcz-Rfz) and the three-dimensional position (Rdx, Rey, Rfz) of the center of the reflector closer to the fixed guntip The third order of the center of the reflector closer to the fixed-side guntip by subtracting the difference (Rax-Rdx, Rby-Rey, Rcz-Rfz) of the three-dimensional positions of the centers of the reflectors calculated by the first calculating means. The difference (Rdx− (Rax−R) between the original position and the three-dimensional position of the center of both reflectors calculated by the first calculating means. x), Rey− (Rby−Rey), Rfz− (Rcz−Rfz)), and a second calculation means for calculating the difference (Rdx− (Rax−Rdx), Rey− (Rby−Rey), A value of Rfz− (Rcz−Rfz)) is a three-dimensional position of the fixed-side guntip.

  In such a configuration, since the distance from the tip of the fixed guntip to the center of the closer reflector and the distance between the centers of both reflectors are the same distance, the difference between the three-dimensional positions of the centers of both reflectors and the fixed The difference in three-dimensional position between the tip of the side gun tip and the center of the reflector closer is the same. For this reason, the difference in the three-dimensional position calculated by the second calculation means becomes the three-dimensional position of the tip of the fixed guntip.

  Therefore, since the position of the tip of the fixed side gun tip is calculated by measuring the positions of both reflectors away from the fixed side gun tip, the position of the tip of the fixed side gun tip can be easily measured regardless of the posture state of the welding gun. .

  In addition, since the attachment is attached to the fixed-side gun tip by fitting, it is not necessary to modify the fixed-side gun to attach the attachment, so the cost of measuring the position of the fixed-side gun tip is the manufacturing cost of the attachment. Can only be.

  As described above, in the laser type three-dimensional measuring machine according to claim 1 of the present invention, the position of the tip of the fixed side gun tip is calculated by measuring the positions of both reflectors separated from the fixed side gun tip. Regardless of the posture state, the position of the tip of the fixed gun tip can be easily measured.

  In addition, since the attachment is attached to the fixed-side gun tip by fitting, it is not necessary to modify the fixed-side gun to attach the attachment, so the cost of measuring the position of the fixed-side gun tip is the manufacturing cost of the attachment. Can only be.

  Therefore, even when the welding gun is inclined, it is possible to easily measure the position of the tip of the fixed gun while suppressing a significant increase in cost.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a main part of a welding site showing an embodiment of the present invention. On the floor F at the welding site, there are a jig 10 for positioning and supporting a workpiece, a welding robot 101 arranged on one side of the jig 10 and a laser coordinate measuring machine 1 arranged on the other side. Each is installed.

  The welding robot 101 includes a robot main body 102 installed on the floor F, and a welding gun 103 rotatably attached to the robot main body 102.

  The welding gun 103 includes a U-shaped arm 104 rotatably attached to the robot body 102, a fixed-side gun 105 provided on one end side of the arm 104 and fixed in position, and the other end side of the arm 104. The movable side gun 106 is provided opposite to the fixed side gun 105 and moves forward and backward with respect to the fixed side gun 105.

  As shown in FIG. 2 (only the fixed-side gun 105 is shown), both guns 105 and 106 are composed of a gun main body 107 attached to the arm 104 and a gun tip 108 attached to the tip of the gun main body 107. The tip 111 of the gun tip 108 constitutes the tip of both guns 105 and 106.

  Inside the gun body 107, a cooling water return channel 109 is formed up to the tip along the gun body 107, and a cooling water supply pipe is provided in the cooling water return channel 109 along the cooling water return channel 109. 110 is arranged.

  On the other hand, as shown in FIGS. 1 and 2, the laser type three-dimensional measuring machine 1 is externally fitted to the measuring machine body 2 installed on the floor F at the welding site and the fixed-side guntip 108 of the welding gun 103. Attachment 3 is provided.

Further, the measuring machine main body 2 includes a laser measuring machine 4 that irradiates and detects a laser, and a control device 5 that is connected to the laser measuring machine 4 via a cable.
The measuring machine main body 2 measures a three-dimensional position of an object to be measured using a laser. For example, a laser tracker manufactured by API or Leica is known.

  The laser measuring machine 4 is provided on the head unit 42, a laser measuring unit body 41 that stands on the floor F and rotates left and right, a head unit 42 that is provided above the laser measuring unit body 41 and rotates up and down. And an irradiation detection unit 43 that performs laser irradiation and detection.

  On the other hand, the control device 5 is composed of a personal computer, and is configured around a CPU 501 as shown in FIG. The CPU 501 is connected to a ROM 502, a RAM 503, a display control unit 505, a transmission control unit 506, a drive control unit 507, an interface 508, and the like.

  The ROM 502 stores a program and the like according to the measurement unit and calculation unit of the present invention, and the RAM 503 stores data being processed.

  A CRT 504 is connected to the display control unit 505, and the display of the CRT 504 is controlled by the display control unit 505. The laser measuring device 4 is connected to the transmission control unit 506 via a cable, and a laser detection signal detected by the laser measuring device 4 is input thereto.

  The laser control device 4 is also connected to the drive control unit 507 via a cable, and the drive control unit 507 controls the operation of the laser measurement device 4 based on a control signal from the CPU 501. A keyboard 509 and a mouse 510 are connected to the interface 508.

  On the other hand, as shown in FIG. 2, the attachment 3 includes an outer fitting portion 31 that fits outside the fixed-side guntip 108, and an extension direction X of the fixed-side guntip 108 that extends outside the fixed-side guntip 108 from the outer fitting portion 31. A reflector mounting portion 32 that extends upward (forward), and is located above the fixed-side gun tip 108 by the reflector mounting portion 32 and is spaced apart vertically along the extending direction X of the fixed-side gun tip 108. It is composed of a pair of reflectors 33 and 34 that are attached and reflect the laser.

  The outer fitting portion 31 is provided with a mounting hole 31d having a round hole shape that can be fitted into the fixed-side gun tip 108 and has a bottom formed in a substantially vertical U-shape so as to cover the fixed-side gun tip 108. In addition, the reflector mounting portion 32 is formed with an upward extending portion 32 a that is integrally formed from the upper surface 31 a of the outer fitting portion 31 and extends upward.

  A pair of through holes 32c and 32c penetrating horizontally (in a direction orthogonal to the extending direction X) in the drawing are formed in the upper extending portion 32a so as to be separated from each other in the vertical direction.

  Further, the reflectors 33 and 34 are a pair of reflector seats that are attached to the reflector main body 33a, 34a having a laser reflecting surface that reflects the laser that hits the reflector and the fixed side gun chip 108 of the upper extension portion 32 so as to be spaced apart vertically. The reflector seats 32b and 32b are formed in a T-shaped cross section. The base 32e is in contact with the inner surface 32d of the upper extension 32a, and protrudes upward from the base 32e. It is comprised from the insertion leg parts 32f and 32f inserted by the through-holes 32c and 32c of the part 32a.

  On the other hand, the reflector bodies 33a and 34a are respectively attached to the base portions 32e and 32e of the reflector seats 32b and 32b, and formed with L-shaped concave surfaces 35 and 35 that form a laser reflecting surface for reflecting the laser. .

  The concave surfaces 35 and 35 are formed in the shape of L-shaped mirrors that face sideways from the base portion 32d of the reflector seat 32b, and the centers of the concave surfaces 35 and 35 constitute the centers 33z and 34z of the reflectors 33 and 34, respectively. ing.

  Further, the reflectors 33 and 34 have the centers 33z and 34z along the extending direction X of the fixed-side guntip 108 from the tip 111 of the fixed-side guntip 108 in a state where the outer fitting portion 31 is externally fitted to the fixed-side guntip 108. The contact portion 31c passes through the extension line Y extending upward, and contacts the tip 111 at the same position as the tip 111 of the fixed-side guntip 108 at the inner surface 31b of the mounting hole 31d formed in the outer fitting portion 31. Reflector mounting so that the distance L1 to the center 34z of the lower reflector 34, which is the reflector closer to the contact portion 31c, and the distance L2 between the centers 33z, 34z of both reflectors 33, 34 are the same distance. It is attached to the part 32.

  In such a configuration, the following procedure is used to measure the three-dimensional position of the tip 111 of the fixed guntip 108 with the laser type three-dimensional measuring machine 1.

  First, the keyboard 509 and the mouse 510 of the control device 5 are operated to rotate the laser measurement unit main body 41 to the left and right, and the head unit 42 to rotate up and down, so that the external fitting is performed on the attachment 3 attached to the fixed-side guntip 108. Aiming at the center 33z of the upper reflector 33, which is a reflector far from the abutting portion 31c of the portion 31, is aimed.

  Then, the laser is emitted from the irradiation detection unit 43 to the center 33z of the upper reflector 33, and the laser reflected from the center 33z of the reflector 33 is detected again by the irradiation detection unit 43 (see FIG. 1).

  The detection signal detected by the irradiation detection unit 43 is output to the control device 5, and the control device 5 performs the center of the reflector 33 from the irradiation detection unit 43 by the CPU 501 based on the input detection signal and the program stored in the ROM 502. The distance to 33z and the rotation angle of the head unit 42, which is the irradiation angle, are calculated, and the three-dimensional position (Rax, Rby, Rcz) of the center 33z of the upper reflector 33 is calculated from the distance and angle by a trigonometric function. .

  Next, the coordinate measuring machine 1 performs the same three-dimensional position (Rdx, Rby, Rcz) measurement procedure of the center 33z of the reflector 33 as described above in accordance with the three-dimensional position (Rdx) of the center 34z of the lower reflector 34. , Rey, Rfz).

  Next, the control device 5 determines the center 34z of the lower reflector 34 from the three-dimensional position (Rax, Rby, Rcz) of the center 33z of the upper reflector 33 measured by the CPU 501 based on the program stored in the ROM 502. The three-dimensional positions (Rdx, Rey, Rfz) are subtracted to calculate the difference (Rax-Rdx, Rby-Rey, Rcz-Rfz) between the centers 33z, 34z of the reflectors 33, 34.

  And the difference (Rax-Rdx, Rby-Rey, Rcz-Rfz) of the three-dimensional positions of the centers 33z, 34z of the reflectors 33, 34 from the three-dimensional position (Rdx, Rey, Rfz) of the center 34z of the lower reflector 34. ) To calculate the difference between the three-dimensional positions (Rdx− (Rax−Rdx), Rey− (Rby−Rey), Rfz− (Rcz−Rfz)), and the measurement is completed.

  In the present embodiment, since the distance L1 from the contact portion 31c of the outer fitting portion 31 to the lower reflector center 34z and the distance L2 between the centers 33z and 34z of both reflectors are the same distance, The difference between the three-dimensional positions of the centers 33z and 34z is the same as the difference between the three-dimensional positions of the fixed guntip tip 111 and the center 34z of the lower reflector. For this reason, the difference between the calculated three-dimensional positions (Rdx− (Rax−Rdx), Rey− (Rby−Rey), Rfz− (Rcz−Rfz)) is the three-dimensional position of the fixed-side guntip tip 111.

  As described above, in the coordinate measuring machine 1 of the present embodiment, the position of the fixed-side guntip tip 111 is calculated by measuring the positions of the reflectors 33 and 34 separated from the fixed-side guntip 108, so that the welding gun 103 The position of the fixed-side guntip tip 111 can be easily measured regardless of the posture state.

  Furthermore, since the attachment 3 is attached by being fitted around the fixed-side gun tip 108, it is not necessary to modify the fixed-side gun 105 in order to attach the attachment 3. For this reason, the cost for measuring the position of the fixed-side gun tip 111 can be reduced to the manufacturing cost of the attachment 3 only.

  Therefore, even when the welding gun 103 is inclined, it is possible to easily measure the position of the fixed-side gun tip 111 while suppressing a significant increase in cost.

It is a principal part perspective view of the welding field which shows one embodiment of this invention. It is a partial cross section figure which shows the stationary side gun of the welding gun with which the attachment of the laser type coordinate measuring machine was attached. It is a block diagram which shows the structure of the control apparatus of a laser type coordinate measuring machine. It is a principal part perspective view of the welding field where the conventional laser type three-dimensional measuring machine is arranged. It is a partial sectional view showing a fixed side gun of a welding gun.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser type three-dimensional measuring machine 2 Measuring machine main body 3 Attachment 31 Outer fitting part 32 Reflector attachment part 33 Reflector 33z center 34 Reflector 34z center 103 Welding gun 105 Fixed side gun 108 Gun tip 111 Tip X Gun tip extending direction Y Extension line

Claims (1)

A measuring machine main body and an attachment that is externally fitted to the fixed gun tip of the welding gun,
The attachment is
An outer fitting portion that is fitted on the fixed-side guntip;
A reflector mounting portion provided extending from the outer fitting portion along the extending direction of the fixed-side guntip;
The reflector mounting portion is located at the front of the fixed-side guntip and is spaced apart along the extending direction of the fixed-side guntip, and includes a pair of reflectors that reflect the laser, and
Both reflectors pass along an extension line whose center extends from the tip of the fixed-side guntip to the front along the extending direction of the fixed-side guntip in a state where the outer fitting portion is externally fitted to the fixed-side guntip. The mounting position on the reflector mounting portion is set so that the distance from the tip of the fixed guntip to the center of the reflector closer to the fixed guntip is the same as the distance between the centers of both reflectors. While
The measuring machine body is
The centers of both reflectors are irradiated with lasers, and the lasers reflected from the centers of both reflectors are detected to detect the three-dimensional positions (Rax, Rby, Rcz), (Rdx, Rey, Measuring means for measuring Rfz);
By subtracting the three-dimensional position (Rdx, Rey, Rfx) of the center of the reflector closer to the fixed-side guntip from the three-dimensional position (Rax, Rby, Rcz) of the reflector far from the fixed-side guntip. First calculating means for calculating a difference (Rax−Rdx, Rby−Rey, Rcz−Rfz) of the three-dimensional position of the center of the reflector;
The difference (Rax−Rdx, Rby) between the centers of the two reflectors calculated by the first calculation means from the three-dimensional position (Rdx, Rey, Rfz) of the center of the reflector closer to the fixed guntip. −Rey, Rcz−Rfz) is subtracted, and the difference (Rdx−) between the three-dimensional position of the center of the reflector closer to the fixed guntip and the center of both the reflectors calculated by the first calculation means (Rax−Rdx), Rey− (Rby−Rey), Rfz− (Rcz−Rfz)), and a second calculating unit.
Laser type three-dimensional measurement characterized in that the value of the difference (Rdx- (Rax-Rdx), Rey- (Rby-Rey), Rfz- (Rcz-Rfz)) is the three-dimensional position of the fixed-side guntip. Machine.

Images