KR200247917Y1 - Touch Sensor of Industrial Robot - Google Patents

Abstract

The present invention relates to a touch sensor for emergency stop of an industrial robot. The present invention is coupled to the upper arm (2) of the robot via the adapter (4) on the same axis in the axial line, the head member 11 is formed with a space 10 therein; A hollow cylindrical housing member 13 coupled to the space 10 of the head member 11 with a sufficient clearance for angular movement; The axial movement of the housing member 13 with respect to the head member 11 is squeezed in the circumferential direction between the one end of the housing member 13 and the boss portion 16 extending coaxially within the head member 11. A plurality of positioning balls 20 to assist; A main spring 12 adapted to elastically press the housing member 13 against the head member 11 via the positioning ball 20; Composed between the rear end of the housing member 13 and the bracket (6) is made of an elastic control means 15 to be able to vary the elastic force of the main spring (12).

Therefore, when the torch or the like collides with another object during the welding operation, even if an external force is applied in any direction and the external force is small, the housing member rotates relative to the head member to operate the switch means, thereby controlling the robot through the controller. Emergency stop. In addition, the same product can be used universally according to the robot's capacity by varying the elastic force of the main spring, and tool center pointing can be easily done without any tools, so that productivity can be expected as well as stable and reliable operation. have.

Description

Touch Sensor of Industrial Robot

The present invention relates to a touch sensor of an industrial robot, and in particular, it can operate with high reliability in response to the direction and magnitude of external force transmitted when the torch part collides with a surrounding object during the operation of the welding robot. It relates to a touch sensor of an industrial robot that can be used universally.

In general, in the case of industrial robots, for example, welding robots, the torch is mounted on the tip of the upper arm via a torch holder to perform welding work. Alternatively, when a torch holder or a welding torch collides with an object due to immature operation, an impact force is applied to the robot, which may cause a malfunction, damage to a part, or seriously damage to a person.

To this end, a touch sensor that detects the impact force when the robot collides with surrounding objects and stops the robot via a control unit has been developed and installed between the tip of the upper arm of the robot and the torch holder.

Looking at an example of such a touch sensor of the industrial robot of the prior art, the touch sensor is detachably mounted via a bracket with an on-off switch made of an electrical contact at the tip of the upper arm of the industrial robot. The welding torch is installed in the torch holder fixed to the housing. The housing is spring-loaded with respect to the guide shaft fastened to the bracket vertically, and is moved upward toward the guide shaft when an external force is applied. A positioning ball is press-fitted between the flange portion of the guide shaft and the upper inner wall of the housing at a predetermined angle in the circumferential direction, that is, at intervals of 120 °.

Therefore, when an external impact force is applied to the housing of the touch sensor, the housing rotates and rises while compressing the spring, and the upper end presses the on / off switch of the bracket to energize the electrical contact. Accordingly, the emergency stop signal is transmitted to the robot controller. It is to stop the robot by outputting.

However, in the conventional touch sensor having the above configuration, the mounting position of the housing for sensing the external force is perpendicular to the axial direction of the upper arm of the robot, and the tip portion of the upper arm with the torch holder fixed to the outer circumferential surface of the housing. Since the structure is offset by a predetermined distance, there is a problem that a separate jig is required to perform a tool center pointing operation for matching the center line of the touch sensor with the welding line of the tip of the torch.

In addition, since the on-off switch has a single contact method, there is a problem in that the switch method must be changed when the characteristics of the controller are changed according to the type of the robot. In addition, since the spring's elastic force, that is, the spring constant is set consistently according to the robot's capacity (load), it is necessary to replace the spring load with a separate touch sensor in order to apply it to other robots. There was a flaw that this fell,

Since the positioning ball is press-installed at an angle, that is, 120 ° interval, between the inner wall of the housing and the flange of the guide shaft, an external force acts on the housing and a force of more than a predetermined size is required to rotate the housing by 120 °. Therefore, there was a problem that there is a limit in the ability to detect external forces.

The present invention is devised to solve the above problems, the object of the present invention is to ensure the reliability of the operation can be detected even in the external shock in any direction and the size of the external force is small. To provide a touch sensor for an industrial robot.

Another object of the present invention is to simplify the management of the industrial robot that can improve the productivity as the same product of a simplified configuration by varying the elastic force of the main spring corresponding to the capacity of several robots It is to provide a touch sensor.

Still another object of the present invention is to provide a touch sensor of an industrial robot, which can easily perform a tool center pointing operation without a separate tool, thereby shortening the preparation time of the robot.

The present invention for achieving the above object is mounted between the front end of the upper arm and the torch of the industrial robot so that the switch means is operated by an external force transmitted from the torch to stop the robot by means of a control unit. A touch sensor of an industrial robot, comprising: a head member coupled to an axial line in the axial direction through an adapter to an upper arm of the robot and having a space formed therein; A hollow cylinder-shaped housing member coupled with a sufficient clearance for angular movement in the space of the head member; A plurality of positioning balls each pressed in a circumferential direction between one tip of the housing member and a boss portion extending coaxially within the head member to assist the angular movement of the housing member relative to the head member; A main spring configured to elastically press the housing member against the head member via a positioning ball; It is characterized in that the touch sensor of the industrial robot including an elastic control means coupled to the rear end of the housing member and the bracket to change the elastic force of the main spring.

According to the present invention having the above-described configuration, when the torch collides with the surrounding object and receives an external force during welding, the housing member may correspond to the head member even if the external force acts in any direction and the size thereof is small. By operating the internal switch means while rotating and sliding relative to the predetermined angle with respect to the output signal to the control unit, it is possible to emergency stop the robot. In addition, since the housing member of the touch sensor is connected on the same axial line of the upper arm, it can be easily matched with the welding line of the torch, so that the tool center pointing operation can be easily performed without a separate tool. According to the capacity, the user can adjust the elastic force of the main spring by means of elastic adjustment means, so that it can be used universally.

1 is a front view of the touch sensor mounted on the welding robot according to an embodiment of the present invention,

2 is a longitudinal sectional view of a touch sensor according to an embodiment of the present invention;

3 is similar to FIG. 2, and shows a state in which the touch sensor of the present invention is operated while the housing member is rotated in response to an external force.

FIG. 4 is a perspective view as viewed in the direction A of FIG. 1, illustrating an operation direction of an external force, a moment, and a torsion angle acting on the touch sensor.

5 is a front view seen from the direction A of FIG.

♣ Explanation of symbols for the main parts of the drawing

1: Touch sensor 3: Torch

4: adapter 6: bracket

7: torch holder 9: switch means

11: head member 12: main spring

13 housing member 16 boss

17: guide ring 18: spring

19: protrusion 20: positioning ball

21: guide shaft 24: sealing member

25 cap member 26 pressurizing member

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the touch sensor of the industrial robot according to the present invention will be described in detail.

1 is a front view of a touch sensor according to an embodiment of the present invention, Figure 2 is a longitudinal cross-sectional view of the touch sensor according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 2, the present invention touch sensor 1 is mounted between the tip of the upper arm 2 of the industrial robot and the welding torch (hereinafter referred to as torch). When (3) collides with the surrounding object and an external force is transmitted therefrom, the control signal is output to a controller (not shown) to emergency stop the robot.

One end of the touch sensor 1 is detachably mounted on the same line as the axial direction of the upper arm 2 of the robot with the bolt 5a via the adapter 4, and the other end thereof is the bolt 5b. Bolts (5c) to the torch holder (7) for supporting the torch (3) via a bracket (6) detachably coupled to each other to adjust the position of the torch (3) with respect to the bracket (6). It is supposed to be. Here, the adapter 4 does not have a specific structure, and the shape and structure are different for each manufacturer, but there is no limitation as long as the adapter 4 can be connected to the upper arm 2 of the robot.

The touch sensor 1 of the present invention is located on the same line as the axial direction of the upper arm 1 of the robot, and thus the intersection point P with the tip extension line L2 of the torch 3 on the extension line L1. That is, the tool center pointing operation to set the initial position in the space of the touch sensor 1 to enter the robot control unit (not shown) so as to meet the position point where the actual welding is made by the ejection of the welding arc becomes extremely simple.

The touch sensor 1 is fastened to the adapter 4 with a bolt 8, has a switch means, and has a space 10 formed therein, and a space portion of the head member 11. 10) and the housing member 13 of a hollow cylindrical shape having a diameter smaller than the diameter of the space portion 10 so as to be coupled at a sufficient interval for angular movement by the elastic force of the main spring 12 in the The rear end of the housing member 13 is provided with an elastic control means 15 is fastened to the bracket 6 by the bolt 14 to adjust the elastic force of the spring 12.

The head member 11 has a hollow boss portion 16 extending from the center of the space portion 10, and one end of the boss portion 16 has a ring-shaped ring formed with a radial flange 17a. The guide ring 17 is slidably inserted so that the guide ring 17 acts as a spring support for the spring 18 to be elastically installed between the inner circumferential surface of the head member 11 and the elastic force of the spring 18. It is to be able to slide in the horizontal direction in FIG.

On the other hand, the other end of the boss portion 16 is formed with a projection 19 having a diameter larger than the guide ring 17 in the radial direction, on one side of the projection 19 a plurality of grooves at a predetermined angle in the circumferential direction 19a are formed, and a plurality of grooves 13a are formed at one end inner circumferential surface of the housing member 13 in the circumferential direction at a closer spacing at positions facing the grooves 19a.

A plurality of steel positioning balls 20 are press-fitted into the grooves 13a and selectively coupled to the grooves 19a by rolling contact with the grooves 19a, thereby providing the housing member 13 to the head member 11. Housing relative to the boss part 16 by adjusting the number of balls 20 inserted between these grooves 13a and 19a according to the environment of the work site or the characteristics of the robot. The relative rotation angle of the member 13, that is, the external force sensing performance can be arbitrarily adjusted. In other words, as the number of balls 20 increases, the rolling contact area of the housing member 13 with respect to the head member 11 increases, so that the housing member 13 can easily rotate relative to a small external force. As a result, the sensing performance of external force is increased.

For example, when 12 positioning balls 20 are press-fitted into the grooves 19a of the boss portion 16 at intervals of 30 °, the housing member 13 has a 30 ° angle with respect to the head member 11. Relative rotation is possible, and similarly, when the three positioning balls 20 are press-fitted into the grooves 19a at 60 ° intervals or three at 120 ° intervals, respectively, the housing members at 60 ° and 120 ° angles, respectively. 13) can be rotated relative to the head member 11, but the smaller the number of the ball 20, the greater the angular range to be rotated, so that a small external force cannot be easily detected.

On the other hand, inside the hollow boss portion 16 of the head member 11, the guide shaft 21, which is generally 'T' shaped and hollow, is fitted so that one end thereof is freely slidable. The other end of the 21 is generally formed integrally with a disk-shaped extension 21a. The main spring 12 is elastically installed between the extension part 21a and the protrusion part 19 of the boss part 16 so that the guide shaft 21 may be elastically supported with respect to the boss part 16.

In addition, the leg 22 of the switch 9 having the electrical contacts 23a, 23b, 23c therein is elastically contacted on the upper surface of the flange 17a of the guide ring 17 of the head member 11, and the guide ring ( According to the sliding operation of 17, the internal electrical contacts 23a, 23b, 23c of the switch 9 are selectively turned on and off to output a control signal to a controller (not shown). Ring 17, spring 18 and leg 22 constitute the switching means.

Here, looking at the configuration of the electrical contact of the switch 9, the electrical contact 23b in the center as a common terminal, the electrical contact 23a to be a normally open terminal and the electrical contact 23c to be a normally closed terminal It is provided so that the connection relationship of these electrical contacts 23a, 23b, 23c can be selected and connected according to the kind of robot.

In addition, a ring-shaped sealing member 24 is mounted between one end of the housing member 13 and the space portion 10 of the head member 11 to block the inflow of foreign matter from the outside.

On the other hand, the elastic adjustment means 15 is fastened to the other end of the housing member 13 by a bolt 14 has a ring-shaped cap member 25 with a threaded portion 25a formed on the inner circumferential surface, and the threaded portion of the cap member 25. The threaded portion 26a is formed on the outer circumferential surface thereof so as to be screwed with the 25a, and the inner circumferential surface of the guide shaft 21 rotates forward and backward in the longitudinal direction of the housing member 13, that is, in the left and right directions in FIG. It is composed of a pressing member 26 in contact with the rear end and pushing it.

The pressure member 26 is a pair of screws 27 are fastened through the bracket 6, and when it is necessary to adjust the elastic force of the main spring 12 according to the capacity of the robot or according to the working conditions, the screw Loosen the 27 and insert a tool such as a wrench into the bolt groove 26b formed at the center of the rear end of the pressing member 26 and turn it clockwise or counterclockwise. Rotating while receiving the guide, the guide shaft 21 is pushed or the pressing force is reduced while advancing to or retracting from the head member 11.

Accordingly, the elastic force of the main spring 12 elastically installed between the extension part 21a of the guide shaft 21 and the protrusion part 19 of the boss part 16 can be adjusted, and as a result, the positioning ball 20 By varying the mutual coupling force between the head member 11 and the housing member 13 via the medium, the housing member 13 is switched to match the operating range of the present invention touch sensor 1, that is, the capacity or working conditions of the robot. It is possible to set the range of the external force, that is, the external force sensing performance, that can emergency stop the robot.

On the other hand, the bolt groove 26b formed at the center of the rear end of the pressing member 26 is also used in the tool center pointing operation for aligning the relative position between the touch sensor 1 and the torch 3, that is, the upper of the robot. In order to align the position of the touch sensor 1 mounted on the arm 2 and input the corresponding coordinate value to the robot controller (not shown), the tool center gauge of the tool center gauge is inserted into the bolt groove 26b of the pressing member 26. When the tip is inserted, it is positioned at the extension line L1 in the axial direction of the upper arm 1, so that when the intersection point P between the tip extension line L2 of the torch 3 is adjusted, the tool center pointing operation is performed. This is made simple, it is possible to eliminate the inconvenience of using a separate jig conventional.

As described above, the cap member 25 is firmly coupled to the bracket 6 by a bolt 5b fastened through the housing member 13 together with the housing member 13, and the pressing member 26. A plurality of circular grooves 26c are formed on the rear surface of the groove at predetermined intervals in the circumferential direction, and the tip portion of the screw 27 is inserted into these grooves 26c to prevent the pressing member 26 from rotating arbitrarily. (6) is firmly supported.

On the other hand, as shown in Figure 1 so that the angle position of the torch holder (7) relative to the bracket (6) during the tool center pointing operation, a plurality of brackets at a predetermined interval, as shown in Figure 1, in this embodiment Two bolt holes 6a are formed, and correspondingly, a long hole 7a is formed at the lower end of the torch holder 7, and the position of the long hole 7a with respect to the hole 6a is varied to correspond thereto. By fastening the adjusting bolt 28, the installation angle of the torch 3 with respect to the upper arm 2 of the robot can be adjusted according to the working environment.

The following describes the operation of the touch sensor of the industrial robot according to the present invention having such a configuration.

During the welding operation using the welding robot equipped with the present invention touch sensor 1, the torch 3 hits the surrounding object due to an accidental failure of the control device, an inexperienced operation of the operator, or an unexpected reason. The external force according to the impact is transmitted to the touch sensor 1 through the torch holder 7 and the bracket 6.

That is, as shown in Figure 4, when the external force due to the impact on the touch sensor 1 in any direction based on the X, Y, Z coordinates, the moment Mx of a predetermined size according to the direction and magnitude of the external force , My and Mz act on the touch sensor 1, respectively. Accordingly, the housing member 13 of the touch sensor 1 is pushed toward the head member 11 to rotate relative to the predetermined angles θX, θY, θZ.

This operation will be described in detail with reference to FIG. 3. When the external force from the torch 3 is transmitted to the housing member 13 via the bracket 6 and the cap member 25 in the state of FIG. While the member 13 is compressed toward the head member 11 while compressing the main spring 12, the member 13 is rotated relative to the member 13 and is inclined by a predetermined angle.

At this time, the degree of inclination of the housing member 13 with respect to the head member 11 will vary depending on the magnitude of the external force transmitted, that is, the positioning ball press-fitted into the groove 19a of the boss portion 16 ( 20, the housing member 13 is maintained by the size of the moment corresponding to the external force while maintaining the elastic rolling contact state by the elastic force of the groove 13a and the main spring 12 of the rotating housing member 13 When rotated, it is seated in the recesses 13a of the housing member 13 and remains in such a state that the housing member 13 with respect to the head member 11 is at an angle, that is, for example, 30 °, 60, Relative rotation is maintained at °, 120 °, etc.

During the relative rotation and sliding of the housing member 13 as described above, the tip of the housing member 13 presses the guide ring 17, and thus the guide ring 17 is a spring 18. While sliding to the left in FIG. 3 while compressing the pressure, the legs 22 of the switch 9 are pressed, whereby the contact 23b of the switch 9 is alternatively turned on or off with the other contacts 23a and 23c. While the corresponding electric signal is output to the controller (not shown), the emergency stop operation of the welding robot is made, so that the operator can check the robot in the stopped state and take necessary measures.

On the other hand, when the operation of the touch sensor 1 as described above is completed, the operator grasps the outer peripheral surface of the housing member 13 to return to the original position while rotating the housing member 13 in the reverse direction of the operation As a result, the housing member 13 returns to the initial position of the boss 16 and the guide shaft 21 by the restoring force of the main spring 12, that is, the state of FIG.

That is, the alignment of the housing member 13 with respect to the head member 11 is made by the elastic force of the main spring 12, wherein the positioning ball 20 is elastic between the grooves 13a and 19a. Rolling contact movement, and returning to the initial position, the housing member 13 by the elastic force of the main spring 12 to maintain the close contact with the head member 11 while the external force is detected. It becomes.

As described above, the touch sensor of the present invention, when the torch collides with the surrounding object during the operation of the welding robot receives the external force, the external force acts in any direction and even if the size of the external force is correspondingly corresponding to the housing As the member rotates and slides, the switch means is operated to output a control signal, thereby enabling the emergency stop operation of the welding robot with high reliability.

In addition, it is configured to easily adjust the elastic force of the main spring even with the same product according to the capacity of the robot, and can be used universally for various robots with different robots or different payloads. Of course, the productivity of the touch sensor can also be improved. When the initial position is set in preparation for the operation of the robot, or even when the torch is shaken or the work point is out of operation, the tool center gauge is inserted into the bolt groove of the pressure member and the toe of the bracket is adjusted by the adjustment bolt. By adjusting the relative position of the anchor holder, the tool center pointing operation is simplified, and the workability of the user can be eliminated, and the workability can be improved.

Claims (4)

In the touch sensor of the industrial robot mounted between the tip of the upper arm of the industrial robot and the torch, the switch means is operated by an external force transmitted from the torch to stop the robot emergencyly through the control unit. A head member (11) coupled to the upper arm (2) of the robot via an adapter (4) on the same axial line and having a space (10) formed therein; A hollow cylindrical housing member (13) coupled to the space (10) of the head member (11) with a sufficient clearance for angular movement; The housing member with respect to the head member 11 is press-fitted in the circumferential direction between one end of the housing member 13 and the boss portion 16 extending coaxially in the head member 11. A plurality of positioning balls 20 for assisting the angular motion of 13); A main spring 12 configured to elastically press the housing member 13 against the head member 11 via the positioning ball 20; Touch sensor of the industrial robot, characterized in that it is coupled between the rear end and the bracket (6) of the housing member 13 so as to vary the elastic force of the main spring (12). A ring-shaped guide ring (17) according to claim 1, wherein said switch means is provided with a radial flange (17a) at one end thereof and slidable with respect to said boss portion (16), and said guide ring (17). ) And a spring (18) for elastically supporting the inner peripheral surface of the head member 11 and the electrical contacts (23a, 23b, 23c) while the contact / separation by the forward and backward movement of the guide ring 17 And a switch (9) having legs (22) for selectively turning on and off. The method of claim 1, wherein the elastic means 15 is slidably along the interior of the boss portion 16 to elastically press the main spring 12 against the boss portion 16. A guide shaft 21 to be fitted, a cap member 25 attached to the housing member 13 and having a threaded portion 25a formed on an inner circumferential surface thereof, and an outer circumferential surface thereof to be screwed into the threaded portion 25a of the cap member 25. The screw member 26a is formed to correspond to the pressing member 26 so that the inner circumferential surface thereof is in contact with the rear end of the guide shaft 21 to push or release the pressing force while being able to move back and forth in the longitudinal direction of the housing member 13. Touch sensor of the industrial robot comprising a. The cap member 25 is formed with a plurality of circular grooves 26b in the circumferential direction on the rear end surface thereof, and the tip end portion of the screw 27 is inserted into these grooves 26b so that the bracket ( 6) Touch sensor of the industrial robot, characterized in that it is supported to be firmly supported while being rotated arbitrarily