JP2013111694A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with leakage of a lubricant as quickly as possible.SOLUTION: An industrial robot 1 includes a main seal member 41 forming a sealed space 46 in which the lubricant is charged by partitioning off a gap 45 of a joint J, one or more auxiliary seal members 42, 43 arranged at an interval so as to partition off the gap 45 outward from the main seal member 41 in order, and a leakage detecting device 50 configured to detect the lubricant leaking into a space 47 between two adjacent seal members 41, 42 from the sealed space 46. The leakage detecting device 50 includes a sucking mechanism 51 which sucks the lubricant out of the space 47, and the sucking mechanism 51 includes suction piping 61 communicating with the interior of the space 47, and a negative pressure applying device 62 which applies negative pressure into the space 47 through the suction piping 61.

Description

  The present invention relates to an industrial robot provided with two or more seal members at a joint.

  An articulated robot is widely known as an example of an industrial robot. The multi-joint robot includes a plurality of arm members that are sequentially connected to be rotatable. A portion that rotatably connects the arm member to the base member, and a portion that rotatably connects the arm member on the distal end side to the arm member on the base side among the two adjacent arm members (hereinafter referred to as “joint portion”) ) Incorporates mechanical elements such as a reduction gear and a bearing. In order to smoothly operate these mechanical elements, an oil seal is provided at the joint portion to seal the lubricant.

  If the fluid or dust outside the robot enters the robot, or the fluid or dust inside the robot is discharged outside the robot, it is necessary to ensure the operational reliability of the robot and to clean the environment where the robot is installed. It is not preferable in terms of maintenance. Therefore, as disclosed in Patent Document 1, in order to seal the inside of the robot from the outside, an oil seal different from that for sealing the lubricant may be provided at the joint. Hereinafter, an oil seal for sealing a lubricant may be referred to as a “main seal”, and another oil seal may be referred to as an “auxiliary seal”.

JP 2001-254787 A

  The main seal and the auxiliary seal are consumables that cannot be deteriorated due to wear and need to be replaced. When the seal at the main seal is broken due to the progress of wear of the main seal, the lubricant leaks into the space between the main seal and the auxiliary seal. However, in the robot disclosed in Patent Document 1, even if the seal at the main seal is broken and the lubricant leaks out, it cannot be easily recognized by a worker in a production factory or a robot maintenance worker.

  The seal at the auxiliary seal is also broken, and the worker recognizes that the seal at the main seal is broken only after the lubricant leaks from the space between the main seal and the auxiliary seal to the outside of the robot. . For this reason, until the lubricant leaks to the outside of the robot, it is difficult for workers to have strong motivation to replace the main seal, and in the meantime, mechanical elements that require lubrication may not work smoothly. There is.

  Also, if the lubricant leaks outside the robot, it is difficult to ensure the cleanliness of the environment where the robot is installed. Patent Document 1 discloses that edible oil is applied to a lubricant when the robot is installed in a food factory. For example, in a pharmaceutical factory particularly sensitive to cleanliness, the leakage of lubricant is disclosed. May seriously affect product quality. For this reason, pharmaceutical factories are different from food factories, and lubricant leakage itself is not allowed regardless of the components of the lubricant. Of course, if it is possible to suppress or prevent the leakage of the lubricant itself in food and other production factories, it is beneficial because it contributes to maintaining the cleanliness of the environment where the robot is installed.

  Therefore, the present invention makes it possible to cope with lubricant leakage as quickly as possible, thereby maintaining the cleanliness of the environment in which the robot is installed, ensuring the operational reliability of the robot, and appropriately replacing the seal. The purpose is to do.

  The present invention has been made to achieve the above object. The industrial robot according to the present invention includes one or more arm members sequentially connected to a base member, and a tip side member of two adjacent members of the base member and the arm member. A joint portion rotatably connected to a proximal end member of the members, a mechanical element incorporated in the joint portion, and a gap formed between the distal end side member and the proximal end member A main seal member that forms an enclosed space in which a lubricant that lubricates the machine element is sealed so as to partition a gap that exposes the machine element and communicates with the outside, and sequentially from the main seal member to the outside. One or more auxiliary seal members arranged at intervals so as to partition the gap, and from the enclosed space into a space between two adjacent seal members of the main seal member and the auxiliary seal member Lubrication A leakage detection device for detecting that the leakage has occurred, the leakage detection device comprising a suction mechanism for sucking out lubricant from the space for detection of leakage, wherein the suction mechanism is disposed in the space. And a negative pressure application device for applying a negative pressure to the space through the suction pipe.

  According to the above configuration, the lubricant can be sucked out by the action of the negative pressure application device before all the seals of the main seal member and the auxiliary seal member are broken and the lubricant leaks to the outside of the robot. It can be detected that the lubricant has leaked from the enclosed space based on the suction of the agent. Therefore, even when the robot is installed in an environment sensitive to cleanliness, the main seal member can be replaced as quickly as possible without contaminating the environment with the lubricant. For this reason, the industrial robot can be suitably applied to an environment sensitive to cleanliness. Further, since the main seal member can be maintained while the leakage of the lubricant is relatively small, it is possible to maintain a state in which the machine element operates smoothly.

  The space between the two adjacent seal members may be a space between the main seal member and the auxiliary seal member adjacent thereto.

  According to the above configuration, it is possible to detect the leakage of the lubricant into the space closest to the main seal member among the spaces formed between the two adjacent seal members. For this reason, it is possible to quickly detect that the lubricant has leaked.

  The leak detection device has a lubricant reservoir for storing the sucked lubricant outside the joint portion, and the lubricant reservoir has a window portion that allows the inside to be visually recognized. May be.

  According to the said structure, the worker of the robot maintenance and the worker of the production factory where the robot is installed can confirm the quantity of the lubricant sucked out through the window part. Therefore, the worker can easily detect that the lubricant has leaked out, and can prompt the worker to replace the seal member appropriately.

  The leak detection device further includes a pressure sensor that detects an internal pressure of the suction pipe, and a detection control unit that determines that the lubricant has leaked when the internal pressure detected by the pressure sensor increases. Also good.

  If the lubricant enters the suction pipe, the internal pressure of the suction pipe increases. According to the said structure, it can detect automatically that the lubricant has leaked using this.

  A filter medium may be provided inside the suction pipe.

  According to the said structure, if the joint of a filter medium will be clogged with the sucked-out lubricant, an internal pressure can be raised notably. For this reason, it is possible to accurately detect whether or not the lubricant has leaked using the pressure sensor.

  The suction pipe has a composite pipe structure including a first pipe and a second pipe that forms a passage independent of the first pipe and surrounds the first pipe, and the first pipe and Both of the second pipes communicate with the space, and the negative pressure application device is configured to apply a negative pressure to the space via the first pipe, and the suction mechanism is configured to apply the negative pressure. During operation of the application device, fluid may be supplied into the space via the second pipe.

  According to the above-described configuration, a smooth flow can be generated from the space to the passage of the first pipe by the fluid fed into the space where the lubricant has leaked through the second pipe, and lubrication in the space can be performed. It becomes easy to suck out the agent well. Since the first pipe and the second pipe have a composite pipe structure, the handling of the suction pipe becomes compact.

  The suction pipe has a plurality of branch portions branched into two or more at one end thereof, and an opening is provided in each of the plurality of branch portions, and the openings are adjacent to each other to define the space. You may arrange | position at intervals in the circumferential direction of the seal member of the two seal members near the said enclosure space.

  According to the configuration, the leaked lubricant can be sucked out satisfactorily regardless of the leak position in the circumferential direction. In the case where the suction pipe includes the first pipe and the second pipe, at least one of the first pipe and the second pipe only needs to have a plurality of branch portions.

  According to the present invention, it is possible to cope with the leakage of the lubricant as quickly as possible, thereby maintaining the cleanliness of the environment in which the robot is installed, and ensuring the operation reliability of the robot. And the seal member can be appropriately replaced. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

It is a side view showing the whole industrial robot composition concerning a 1st embodiment of the present invention. It is a schematic diagram which shows the structure of the joint part of the industrial robot shown in FIG. 1, and a leak detection apparatus. FIG. 3A is a schematic diagram showing the configuration of the joint part and the leak detection device of the industrial robot according to the second embodiment of the present invention. FIG. 3B is a cross-sectional view of the suction pipe cut along the line bb in FIG. It is a schematic diagram which shows the structure of the joint part and leak detection apparatus of the industrial robot which concern on 3rd Embodiment of this invention. FIG. 5A is a schematic diagram showing the configuration of the joint portion and the leak detection device of the industrial robot according to the fourth embodiment of the present invention. FIG.5 (b) is sectional drawing of the joint part cut | disconnected and shown along the bb line of Fig.5 (a).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is the same or respond | corresponds through all the figures, and the detailed description which overlaps is abbreviate | omitted.

[First Embodiment]
(Overall configuration of industrial robot)
FIG. 1 is a side view showing the overall configuration of the industrial robot according to the first embodiment of the present invention. As shown in FIG. 1, the industrial robot 1 includes a base member 2 and a plurality of arm members 3 to 8 that are sequentially connected from the base member 2. A tool 9 for performing a required work is detachably attached to the tips of these members 3-8. The tool 9 can be applied with a torch or gun for performing a welding operation, or a gun for performing a painting operation, in addition to a gripping tool or a suction tool for performing a picking operation. In FIG. 1, a so-called vertical articulated 6-axis robot is illustrated as the industrial robot 1 according to this embodiment, but this is merely an example, and the present invention is applied to other types of robots. Can also be suitably applied.

  The base member 2 is installed at a work site in a production factory such as a food factory or a pharmaceutical factory. In addition, in FIG. 1, although the case where the base member 2 is fixed on the horizontal floor surface of a work site is illustrated, it may be installed on the non-horizontal surface and is suspended from the top. Or it may be movably installed. The plurality of arm members 3 to 8 include a first arm member 3, a second arm member 4, a third arm member 5, a fourth arm member 6, a fifth arm member 7 and a sixth arm member 8. In this order, the arm members 3 to 8 are sequentially connected from the base member 2. That is, the first arm member 3 is connected to the base member 2 at the base end portion, the second arm member 4 is connected to the tip end portion of the first arm member 3 at the base end portion, and so on. The arm member 8 is connected to the distal end portion of the fifth arm member 7 at the proximal end portion. The tool 9 is detachably attached to the distal end portion of the sixth arm member 8.

  The industrial robot 1 includes a plurality of joint portions J1 to J6. Each joint part J1-J6 is the base member 2 among the two members adjacent to the base member 2 and the arm members 3-8 connected sequentially, and the base end member of the two members. Are connected to be rotatable. The “tip-side member” is a member disposed on the tool 9 side among two adjacent members. The “proximal end member” is a member disposed on the opposite side. In the present embodiment, since the total number of the base member 2 and the arm members 3 to 8 is 7, the number of pairs of the adjacent proximal side member and the distal side member is 6, and the number of joint portions J1 to J6. Is also six. However, the number of the joint portions J1 to J6 is not particularly limited, just as the industrial robot 1 is not limited to the six-axis robot.

  For example, the first joint portion J1 connects the distal end side member (first arm member 3) to the proximal end side member (base member 2) so as to be rotatable around the first rotation axis A1. The second joint portion J2 connects the distal end side member (second arm member 4) to the proximal end side member (first arm member 3) so as to be rotatable around the second rotation axis A2, and the third to sixth portions. The joints J3 to J6 are similar to this. In FIG. 1, reference symbol A3 is a third rotation axis that serves as the rotation center of the distal end side member (third arm member 5) in the third joint portion J3. Reference sign A4 is a fourth rotation axis that is the center of rotation of the distal end side member (fourth arm member 6) in the fourth joint portion J4. Reference sign A5 is a fifth rotation axis serving as the rotation center of the distal end side member (fifth arm member 7) in the fifth joint portion J5. Reference symbol A6 is a sixth rotation axis serving as a rotation center of the distal end side member (sixth arm member 8) in the sixth joint portion J6. The 1st-6th arm members 3-8 become a front end side member in each of the 1st-6th joint parts J1-J6, and can rotate mutually independently around the corresponding axis of rotation A1-A6. In the present embodiment, the joints J1 to J6 allow the tip side member to rotate about one axis, but the tip side member may allow rotation about two axes or three axes.

  FIG. 2 is a conceptual diagram showing the configuration of the joint J and the leak detection device 50 of the industrial robot 1 shown in FIG. In FIG. 2, of the six joint portions J1 to J6, the first joint portion J1 in which the base member 2 becomes the proximal end member 11 and the first arm member 3 becomes the distal end side member 21 is representatively illustrated. However, the other joint portions J2 to J6 have the same configuration. Therefore, hereinafter, matters that can correspond to any of the first to sixth joint portions J1 to J6 will be described using the reference symbol “J” attached to the joint portion shown in FIG. Similarly, the rotation axis will be described using the reference symbol “A”. The leak detection device 50 is a device for detecting leakage of the lubricant applied to the joint portion J. The leak detection device 50 may be provided corresponding to all the joint portions J1 to J6, or may correspond to only one or a plurality of partial joint portions.

(Joint part)
As shown in FIG. 2, the joint portion J can rotate the distal end coupling portion 22 provided at the proximal end portion of the distal end side member 21 to the proximal end coupling portion 12 provided at the distal end portion of the proximal end side member 11. It is comprised so that it may connect. For example, the two connecting portions 12 and 22 are formed in a cylindrical shape having openings at end portions in the axial direction. The connecting portions 12 and 22 are fitted coaxially and so that the two openings face each other in the axial direction. In addition, although the case where the front-end | tip connection part 22 is fitted by the outer side of the base end connection part 12 is illustrated in FIG. 2, you may reverse inside and outside.

  By fitting the connecting portions 12 and 22 in this way, a gap 45 is formed between the two connecting portions 12 and 22. The tip connecting portion 22 has an inner wall 23 protruding from the inner peripheral surface, and the inner wall 23 is provided at a position deeper in the axial direction than the opening of the tip connecting portion 22. A mechanical element for rotationally driving the distal end side member 21 is accommodated in the gap 45 on the proximal end side when viewed from the inner wall 23.

  The machine elements include, for example, a motor unit 31, a reduction gear unit 32, and an output shaft 33. The output shaft 33 is connected to the central portion of the inner wall 23 at one end thereof, and extends from the inner wall 23 toward the inside of the proximal end connecting portion 12. The reduction gear unit 32 is formed in a substantially cylindrical shape and is disposed so as to surround the output shaft 33. The motor unit 31 extends from the reduction gear unit 32 toward the inside of the proximal end connecting portion 12. When the motor unit 31 operates, the rotation of the motor unit 31 is transmitted to the output shaft 33 via the reduction gear unit 32, and the rotation of the output shaft 33 is transmitted to the inner wall 23. As a result, the central axis of the output shaft 33 becomes the rotational axis A of the distal end side member 21, and the distal end side member 21 rotates around the rotational axis A. Although not shown in detail, other machine elements include a bearing (not shown) that rotatably supports the output shaft 33.

  The gap 45 is a portion where the connecting portions 12 and 22 face each other in the axial direction, a portion where the reduction gear unit 32 installed in the base end connecting portion 12 and the distal end connecting portion 22 overlap in the radial direction, or the connecting portion 12. , 22 are communicated (opened) to the outside of the industrial robot 1 through the overlapping portion in the radial direction. Further, the mechanical element is housed in the gap 45, and thus is incorporated in the joint portion J so as to be exposed in the gap 45.

  On the other hand, it is necessary to lubricate the speed reducer unit 32, the bearing that supports the output shaft 33, and the like in order to smoothly operate the mechanical element and rotate the distal end side member 21 smoothly. Therefore, a main seal member 41 is provided at the joint portion J. The main seal member 41 forms a sealed enclosure space 46 so as to partition the gap 45. A lubricant for lubricating the machine element is enclosed in the enclosure space 46. The main seal member 41 is, for example, an annular oil seal, and forms a sealed enclosure space 46 while allowing the output shaft 33 to rotate. When an oil seal is applied to the main seal member 41, the oil seal may take any form, and may or may not have a spring, or may have a dust guard. The outer peripheral surface may be made of rubber, metal, or resin. The lubricant in the enclosed space 46 may be in any form as long as it can lubricate the machine element. For example, a sponge body soaked with a lubricant may be enclosed in the enclosed space 46, or a liquid lubricant may be enclosed in the enclosed space 46 as it is. The lubricant may be a mineral oil-based lubricating oil, an edible lubricating oil, or a lubricating oil of other components.

  The joint portion J is provided with one or more auxiliary seal members 42 and 43 arranged at intervals so as to partition the gap 45 in order from the main seal member 41 to the outside. In this embodiment, the 1st auxiliary seal member 42 and the 2nd auxiliary seal member 43 are provided in this order toward the exterior from the main seal member 41 as one or more such auxiliary seal members. Since the two auxiliary seal members 42 and 43 are provided in this way, the gap 45 is formed in the first space 47 formed between the aforementioned enclosed space 46 and the main seal member 41 and the first auxiliary seal member 42. And a second space 48 formed between the first auxiliary seal member 42 and the second auxiliary seal member 43. The enclosure space 46, the first space 47, and the second space 48 approach the outside in this order. In other words, the enclosed space 46 is adjacent to the first space 47 via the main seal member 41, the first space 47 is adjacent to the second space 48 via the first auxiliary seal member 42, The second space 48 is adjacent to the outside through the second auxiliary seal member 43.

  In the present embodiment, the speed reducer unit 32 is installed at the edge of the opening of the proximal end connecting portion 12, so that the outer peripheral surface of the speed reducer unit 32 is close to and opposed to the inner peripheral surface of the distal end connecting portion 22. Yes. Therefore, the gap 45 communicates (opens) to the outside via a ring-shaped clearance between the outer peripheral surface and the inner peripheral surface. Therefore, both the first auxiliary seal member 42 and the second auxiliary seal member 43 are fitted into a ring-shaped clearance between the inner peripheral surface of the tip connecting portion 22 and the outer peripheral surface of the reduction gear unit 32. When the reduction gear unit 32 is disposed inside the proximal end connecting portion 12, the gap 45 provides a clearance between the inner peripheral surface of the distal end connecting portion 22 and the outer peripheral surface of the proximal end connecting portion 12. It communicates with the outside through. In such a case, the first auxiliary seal member 42 or the second auxiliary seal member 43 may be provided so as to be in close contact with the outer peripheral surface of the proximal end connecting portion 12. Both the first auxiliary seal member 42 and the second auxiliary seal member 43 are, for example, O-type oil seals, which are suitably fitted into a ring-shaped clearance. Similar to the main seal member 41, any form of oil seal may be applied to the first auxiliary seal member 42 and the second auxiliary seal member 43.

  When the main seal member 41 and the auxiliary seal members 42 and 43 are provided in this way, the machine element is always lubricated with the lubricant enclosed in the enclosed space 46, and the distal end side member 21 operates smoothly. Further, even if dust such as abrasion powder is discharged from the machine element into the gap 45, the dust can be captured in the enclosed space 46, the first space 47, or the second space 48. Therefore, it can suppress that the dust generated inside the industrial robot 1 is discharged | emitted outside, and can keep a work site clean. Conversely, even when cleaning the industrial robot 1, the sealing action of the second auxiliary seal member 43 prevents moisture, detergent, or dust from entering the inside of the industrial robot 1 from the outside. Can do.

  Since the main seal member 41 and the auxiliary seal members 42 and 43 function as packings, they are worn with the rotation of the distal end side member 21. If the seal of the main seal member 41 is broken due to the progress of wear of the main seal member 41, the enclosed space 46 is undesirably communicated with the first space 47, and the lubricant can leak into the first space 47. There is sex. If the sealing at the first auxiliary seal member 42 is also broken, the lubricant may leak from the first space 47 to the second space 48, and if the sealing at the second auxiliary seal member 43 is also broken. The lubricant may leak out from the second space 48 to the outside. In order to deal with such a situation as quickly as possible, the industrial robot 1 according to the present embodiment includes a leak detection device 50 for detecting leakage of the lubricant. Hereinafter, the configuration and operation of the leak detection device 50 according to the present embodiment will be described.

(Leakage detection device)
In the leak detection device 50, the lubricant leaks from the enclosed space 46 into the space 47 (or 48) between two adjacent seal members of the main seal member 41 and the auxiliary seal members 42 and 43. It is a device for detecting. In the present embodiment, the two adjacent seal members are the main seal member 41 and the first auxiliary seal member 42, and the space between the two adjacent seal members is the first space 47 described above.

  The leak detection device 50 includes a suction mechanism 51 that sucks out lubricant from the first space 47 in order to detect leakage. The suction mechanism 51 includes a suction pipe 61 and a negative pressure application pump 62. The suction pipe 61 is a circular pipe made of a flexible material, and has an opening 61a at one end. The opening 61 a of the suction pipe 61 is disposed in the first space 47, whereby the inside of the suction pipe 51 communicates with the first space 47. The other end of the suction pipe 61 is drawn out of the industrial robot 1. In order to handle in this way, in the present embodiment, a through-hole 34 that penetrates the motor unit 31, the speed reducer unit 32, and the output shaft 33 in the axial direction is provided. In addition, the inner wall 23 has a central port 23 a communicating with the through hole 34 at the center thereof. Furthermore, the inner wall 23 has a pipe insertion port 23b that faces the first space 47 in a portion separated from the center port 23a in the radial direction. Since the pipe insertion port 23 b faces the first space 47, the pipe insertion port 23 b is located on the radially outer side with respect to the outer peripheral surface of the output shaft 33. On the other hand, the proximal end member 11 is also provided with a pipe insertion port 13.

  When the suction pipe 61 is viewed from the outside of the industrial robot 1, first, the suction pipe 61 enters the inside of the proximal end side member 11 through the pipe insertion port 13 and is directed toward the joint portion J. The suction pipe 61 enters the inside of the through hole 34 from the end opposite to the inner wall 23 in the proximal end connecting portion 12, passes through the through hole 34, and passes from the center port 23 a of the inner wall 23 to the distal end side member 21. Inside. Further, the suction pipe 61 is folded inside the distal end side member 21 and enters the inside of the first space 47 through the pipe insertion port 23 b of the inner wall 23. One end of the suction pipe 61 is opened in the first space 47. Thus, the suction pipe 61 extends through the through hole 34 and is disposed on the rotation axis A or in the vicinity thereof. For this reason, even if the front end side member 21 rotates around the rotation axis A, it is possible to suppress the suction pipe 61 from swinging greatly. Further, since the suction pipe 61 has flexibility, it easily follows the movement of the distal end side member 21.

  The negative pressure application pump 62 is installed, for example, outside the industrial robot 1 and connected to the other end of the suction pipe 61. When the negative pressure application pump 62 operates, a negative pressure can be applied to the first space 47 through the suction pipe 61. Here, the “negative pressure” may be a pressure smaller than the atmospheric pressure or a pressure smaller than the internal pressure of the enclosed space 46.

  If the seal at the main seal member 41 is broken and the lubricant leaks from the enclosed space into the first space 47, a negative pressure is applied to the first space 47 via the suction pipe 61. Together with the air in the first space 47, the lubricant is guided to the inside of the suction pipe 61 through the opening 61 a. The lubricant sucked out from the first space 47 flows out along the suction pipe 61 to the outside of the joint portion J (that is, outside the industrial robot 1). As described above, in the industrial robot 1 according to the present embodiment, the lubricant is sucked out before the main seal member 41 and the auxiliary seal members 42 and 43 are all broken and the lubricant leaks outside the industrial robot 1. be able to. For this reason, even if the industrial robot 1 is installed in an environment sensitive to cleanliness, the environment is not contaminated with the lubricant.

  The leak detection device 50 further includes a lubricant reservoir 52, a pressure sensor 53, a detection control unit 54, an alarm device 55, and a filter 56 in order to automatically detect or support detection of lubricant leakage. The lubricant reservoir 52 is provided outside the joint portion J (that is, outside the industrial robot 1) and stores the lubricant sucked out by the suction mechanism 51. The lubricant reservoir 52 is formed in a sealed container shape, for example, and is connected to the suction pipe 61. The lubricant reservoir 52 has a window portion 62a made of a light-transmitting material on part or all of the side wall.

  When such a lubricant reservoir 52 is provided, the worker can visually recognize the inside of the lubricant reservoir 52 through the window 62a while staying at the work site of the industrial robot 1 without disassembling the industrial robot 1. So that it is easy to know how much lubricant is being sucked out. Therefore, the worker can appropriately determine whether or not the lubricant has leaked from the enclosed space 46 based on the amount of lubricant stored in the lubricant reservoir 52. In this way, the worker is motivated to replace the main seal member 41 before the lubricant breaks the seal at the second auxiliary seal 42 and leaks to the outside of the joint portion J. Appropriate replacement of the member 41 can be promoted.

  The pressure sensor 53 detects the internal pressure of the suction pipe 61. The detection control unit 54 includes a CPU, a memory, and an input / output interface. The detection control unit 54 is connected to the negative pressure application pump 623, and the negative pressure application pump 62 is operated so that the negative pressure application pump 62 is activated and stopped at a required timing. 62 is controlled. The negative pressure application pump 62 may operate constantly when the industrial robot 1 is operating, or may operate intermittently while the industrial robot 1 is operating. Moreover, it may operate when the industrial robot 1 is stopped, or may operate intermittently regardless of whether the industrial robot 1 is operating or stopped. In order to control the start timing and stop timing of the negative pressure application pump 62, the detection control unit 54 includes a robot operation signal indicating that the industrial robot 1 is operating, or a start command for the negative pressure application pump 62 and A stop command may be input.

  As described above, when the negative pressure application pump 62 operates, a negative pressure is applied in the first space 47. When the seal at the main seal member 41 is broken and the lubricant leaks into the first space 47, the lubricant passes from the first space 47 through the opening 61 a of the suction pipe 61 into the suction pipe 61. It is guided and flows in the suction pipe 61 toward the other end. When the lubricant flows in the suction pipe 61 in this way, the internal pressure of the suction pipe 61 increases. The detection control unit 54 monitors the internal pressure of the suction pipe 61 sent from the pressure sensor 53 when the negative pressure supply pump 62 is operating. Then, when the value of the internal pressure sent from the pressure sensor 53 increases, the detection control unit 54 determines that the lubricant has leaked into the first space 47 based on this. When the detection control unit 54 determines that the lubricant has leaked into the first space 47, the detection control unit 54 operates the alarm device 55.

  As described above, when the leakage detection device 50 includes the pressure sensor 53 and the detection control unit 54, it is possible to automatically detect leakage of the lubricant. For this reason, it contributes to reduction of a worker's work burden. Further, when the leakage of the lubricant is automatically detected, the alarm device 55 is automatically activated to warn the worker. For this reason, it is possible to prompt the operator to replace the main seal member 41 appropriately. The alarm device 55 may be one that appeals to the hearing of the worker by, for example, a buzzer or voice guidance, or may appeal to the worker's vision by a display that prompts replacement on the display device.

  In the present embodiment, a filter 56 is provided inside the suction pipe 61. If the filter 56 is provided, the internal pressure of the suction pipe 61 can be remarkably increased when the joint of the filter 56 is clogged with the lubricant sucked out from the first space 47. Thereby, it is possible to accurately detect whether or not the lubricant has leaked using the pressure sensor 53. The filter 56 may be applied in any form, may be made of sintered metal, may be made of a non-woven fabric having oil adsorption properties, or may be made of a highly porous material. It may be made of a molecular compound.

  As described above, according to the leak detection device 50 according to the present embodiment, it becomes possible to automatically detect the leak of the lubricant based on the sucked-out lubricant, and sufficiently support the worker to detect the leak. be able to. Therefore, the main seal member 41 can be appropriately replaced without contaminating the work site of the industrial robot 1 with the lubricant. Therefore, the industrial robot 1 can be suitably applied to an environment sensitive to cleanliness.

  Further, since the lubricant leakage can be detected before the lubricant passes through the first space 47 and the second space 48 and leaks to the outside, as a result, the leaked amount is relatively small. The main seal member 41 can be replaced within a short time. Therefore, the main seal member 41 can be replaced while maintaining the state in which the machine element operates smoothly. In particular, in the present embodiment, the lubricant is sucked out from the first space 46 between the main seal member 41 and the first auxiliary seal member 42 adjacent thereto. For this reason, it is possible to detect the leakage of the lubricant into the space near the main seal member 41 in the gap 45, and it is possible to quickly detect that the lubricant has leaked.

[Second Embodiment]
FIG. 3A is a conceptual diagram showing the configuration of the joint J and the leak detection device 250 of the industrial robot 201 according to the second embodiment of the present invention. FIG. 3B is a cross-sectional view of the suction pipe 261 shown cut along the line bb in FIG. In the second embodiment, the configuration of the joint portion J is the same as that of the first embodiment, but the configuration of the leak detection device 250 including the configuration of the suction mechanism 251 is different from that of the first embodiment. . Hereinafter, the industrial robot 201 according to the second embodiment will be described focusing on differences from the first embodiment.

  As shown in FIG. 3A, the leak detection device 250 according to the second embodiment includes a suction mechanism 251 and a detection control unit 254. Although not shown in FIG. 3A, the leak detection device 250 according to the second embodiment also includes a lubricant reservoir, a pressure sensor, and an alarm device similar to those in the first embodiment. Therefore, the worker can detect the leakage of the lubricant using the lubricant pool, and the detection control unit 254 can automatically detect the leakage of the lubricant based on the input from the pressure sensor. It is possible to alert the worker of the leakage of the lubricant.

  The suction mechanism 251 includes a suction pipe 261, a negative pressure supply pump 262, and a fluid supply pump 263. The suction pipe 261 has an opening 261 a at one end, and the opening 261 a is located in the first space 47. In the present embodiment, the suction pipe 261 has a so-called double pipe structure or a composite pipe structure. In other words, the suction pipe 261 includes a first pipe 266 having a small diameter and a second pipe 267 that surrounds the first pipe 266, and the first pipe 266 and the second pipe 267 constitute mutually independent passages. doing.

  As shown in FIG. 3B, a circular section passage surrounded by the inner peripheral surface of the first pipe 266 is provided in the central portion of the suction pipe 261, and the outer periphery of the first pipe 266 is provided outside the passage. A passage having an annular cross section surrounded by the surface and the inner peripheral surface of the second pipe 267 is provided, and these two passages are isolated by the wall of the first pipe 266. The opening 261a of the suction pipe 261 includes an opening 266a of the first pipe 266 arranged at the center and an opening 267a of the second pipe 267 arranged outside the first pipe 266. Both openings 266 a and 267 a are located in the first space 47, and both the first pipe 266 and the second pipe 267 communicate with the first space 47.

  As shown in FIG. 3A, the first pipe 266 is connected to the negative pressure application pump 262 at the other end. The second pipe 267 is connected to the fluid supply pump 263 at the other end. The detection control unit 254 is connected to the negative pressure application pump 262 and the fluid supply pump 263, and has a required period so as to start and stop the negative pressure application pump 262 and the fluid supply pump 263 synchronously at a required timing. The negative pressure application pump 262 and the fluid supply pump 263 are controlled so that the negative pressure application pump 262 and the fluid supply pump 263 are operated in synchronization. When the negative pressure application pump 262 operates is the same as in the first embodiment. The fluid supply pump 263 is controlled to operate during operation of the negative pressure application pump 262.

  When the fluid supply pump 263 operates, the fluid flows from the other end portion to the one end portion through the second pipe 267, and the fluid is supplied into the first space 47 through the opening 267a of the second pipe 267. The This fluid may be a liquid or a gas. When the fluid is a liquid, the liquid does not corrode the machine elements, the base end side member 11 and the front end side member 21, and maintains cleanliness in the environment where the industrial robot 201 is installed. What does not affect is applied.

  At the same time, the negative pressure application pump 262 is operating. Then, the fluid supplied from the second pipe 267 is guided into the first pipe 266 through the opening 266a of the first pipe 266. Thereby, a smooth flow of the fluid can be formed in the first pipe 266 from the first space 47 toward the other end of the first pipe 266. Therefore, if the sealing at the main seal member 41 is broken and the lubricant leaks into the first space 47, the leaked lubricant can be smoothly sucked into the first pipe 266 together with the fluid.

  As described above, in the present embodiment, the suction pipe has a double pipe structure or a composite pipe structure having a pipe dedicated for introducing fluid and a pipe dedicated for suction. The fluid supply pump 263 and the pipe structure The fluid flow is positively formed in the pipe dedicated to the suction. As a result, even if a small amount of lubricant leaks out, the amount of lubricant can be satisfactorily sucked out, improving the effect of preventing leakage to the outside and reducing the lubricant leakage. It can be detected more accurately.

  When the fluid is a liquid, it is preferable that the suction side of the fluid supply pump 263 and the discharge side of the negative pressure application pump 262 are connected to a pan for storing the liquid so that the liquid is circulated. Moreover, it is preferable that a liquid changes color by mixing with a lubricant. Then, the worker can determine the presence or absence of the leakage of the lubricant based on the presence or absence of the color change of the liquid sucked through the first pipe 266, and further the lubricant based on the degree of the color change. The amount of leakage or the progress of wear of the main seal member 41 can be determined.

[Third Embodiment]
FIG. 4 is a conceptual diagram showing the configuration of the joint J and the leak detection device 350 of the industrial robot 301 according to the third embodiment of the present invention. In 3rd Embodiment, while the structure of the joint part J is the same as that of the said embodiment, the structure of the leak detection apparatus 350 including the structure of suction piping is different from the thing of the said embodiment. Hereinafter, the industrial robot 301 according to the third embodiment will be described focusing on differences from the above embodiment.

  As shown in FIG. 4, the leak detection device 350 according to the third embodiment includes a suction mechanism 351 and a detection control unit 354. As in the second embodiment, the leak detection device 350 according to the third embodiment also includes a lubricant reservoir, a pressure sensor, and an alarm device.

  The suction mechanism 351 includes a suction pipe 361 and a negative pressure supply pump 362. The suction pipe 361 is similar to that of the second embodiment. That is, the suction pipe 361 includes a first pipe 366 having a small diameter and a second pipe 367 surrounding the first pipe 366, and has a so-called double pipe structure or a composite pipe structure. The first pipe 366 and the second pipe 367 constitute mutually independent passages. The suction pipe 361 has an opening 361a at one end, and the opening 361a has an opening 366a of the first pipe 366 arranged at the center and an opening 367a of the second pipe 367 arranged outside the opening 361a. included. Both openings 366 a and 367 a are located in the first space 47, and both the first pipe 366 and the second pipe 367 communicate with the first space 47.

  The first pipe 366 is connected to the negative pressure application pump 362 at the other end. The second pipe 367 has a fluid supply port 367b open to the atmosphere at the other end. The detection control unit 354 is connected to the negative pressure application pump 362 and controls the negative pressure application pump 362 as in the first embodiment.

  When the negative pressure application pump 362 is activated, a negative pressure is applied to the first space 47 through the first pipe 366. Thereby, the atmosphere is drawn into the first space 47 from the fluid supply port 367b via the second pipe 367. The air drawn into the first space 47 is guided into the first pipe 366 through the opening 366 a of the first pipe 366. As a result, a smooth air flow can be formed in the first pipe 366 from the first space 47 toward the other end of the first pipe 366. Therefore, if the sealing at the main seal member 41 is broken and the lubricant leaks into the first space 47, the leaked lubricant is contained in the first pipe 366 together with the air drawn into the first space 47. It is sucked in smoothly. As a result, similarly to the second embodiment, even if the leaked lubricant is a very small amount, the small amount of the lubricant can be satisfactorily sucked out.

  In this embodiment, since the atmosphere is used for the fluid, it is not necessary to install a pan for storing the fluid, and the leaked lubricant can be suitably stored in the lubricant reservoir. In addition, since a dedicated device for pumping fluid such as a pump is not provided, the overall device configuration of the industrial robot 1 can be simplified. In using the atmosphere, the suction pipe 361 has a so-called double pipe structure or a composite pipe structure, and a fluid supply port 367b communicating with the atmosphere is provided at the other end of the second pipe 367 drawn to the outside of the joint portion J. It has been. It is possible to avoid providing a hole for air communication in the base end connection part 12 or the front end connection part 22, and it is possible to prevent dust and moisture from passing between the inside and outside of the robot through such a hole.

[Fourth Embodiment]
FIG. 5A is a conceptual diagram showing the configuration of the joint J and the leak detection device 450 of the industrial robot 401 according to the fourth embodiment of the present invention. FIG. 5B is a cross-sectional view of the joint portion J cut along the line bb in FIG. In the fourth embodiment, the configuration of the joint portion J is substantially the same as that of the above embodiment, but the configuration of the leak detection device 450 including the suction pipe 461 is different from that of the above embodiment. Accordingly, the structure of the tip connecting portion 22 is different from that of the above embodiment. Hereinafter, an industrial robot 401 according to the fourth embodiment will be described focusing on differences from the above embodiment.

  As shown in FIG. 5A, the leak detection device 450 according to the fourth embodiment includes a suction mechanism 451, a lubricant reservoir 52, and a filter 56. Although not shown in FIG. 5A, the leak detection device 450 according to the fourth embodiment also includes the same pressure sensor, detection control unit, and alarm as those in the first embodiment, and the detection control unit is a pressure sensor. It is possible to automatically detect the leakage of the lubricant based on the input from the engine, and to alert the worker of the leakage of the lubricant.

  The suction mechanism 451 includes a suction pipe 461 and a negative pressure supply pump 462. The suction pipe 461 according to the present embodiment has a single-pipe structure as in the first embodiment (unlike the second and third embodiments). The suction pipe 461 has a common portion 471 and a plurality of branch portions 472 branched from one end of the common portion 471 into two or more. Each branch portion 472 has an opening 472 a at one end, and each opening 472 a is located in the first space 47.

  When the suction pipe 461 is viewed from the outside of the industrial robot 1, first, the common portion 471 enters the inside of the base end side member 11 through the pipe insertion port 13 of the base end side member 11, and enters the joint portion J. Is heading. The common portion 471 enters the inside of the through hole 34 from the end opposite to the inner wall 23, passes through the through hole 34, and enters the inside of the distal end side member 21 from the center port 23 a of the inner wall 23.

  The plurality of branch portions 472 are branched from the common portion 471 inside the distal end side member 21. The inner wall 23 has a plurality of pipe insertion ports 23b in a portion away from the center port 23a radially outward. The plurality of pipe insertion ports 23b are arranged at equal intervals in the circumferential direction around the rotation axis A. Each branch portion 472 enters the first space 47 through the corresponding pipe insertion port 23 b, and each opening 472 a is opened in the first space 47.

  As shown in FIG. 5B, the plurality of branch portions 472 include a main seal member 41 that is closer to the enclosed space 46 among the main seal member 41 and the first auxiliary seal member 42 that define the first space 47. Are arranged at equal intervals in the circumferential direction. Although not shown in FIG. 5B, the arrangement of the openings 472a is the same as this. In the present embodiment, the case where the number of the branch portions 472 is four is illustrated, but the number of the branch portions 472 is not particularly limited.

  As shown in FIG. 5A, the negative pressure application pump 472 is installed, for example, outside the industrial robot 1 and is connected to the other end of the common portion 471 of the suction pipe 461. When the negative pressure application pump 462 operates, a negative pressure can be applied in the first space 47 through the suction pipe 461. In the present embodiment, the suction pipe 461 has a plurality of branch portions 472 at one end, and the opening 472 a of each branch portion 472 is located in the first space 47. For this reason, when the lubricant leaks from the enclosed space 46 into the first space 47, it is not affected by the position in the circumferential direction where the seal of the main seal member 41 is broken, The leaked lubricant can be sucked out through any of the plurality of branch portions 472.

[Modification]
From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  For example, the lubricant reservoir may be omitted and only automatic detection by the detection control unit may be performed. Conversely, the detection control unit may be omitted and only detection by an operator using a lubricant reservoir may be performed. In any case, leakage of the lubricant can be detected by sucking out the lubricant using the suction mechanism. When both the lubricant reservoir and the detection control unit are provided, the leak detection device may include a liquid level sensor that detects that the level of the lubricant reservoir exceeds a predetermined level. At this time, the detection control unit can automatically determine the leakage of the lubricant based on the input from the liquid level sensor. At this time, a pressure sensor may be used together or may be omitted. Further, the device for applying the negative pressure is not limited to the pump, and may be another device such as a compressor.

  Even when the suction pipe has the first pipe and the second pipe, the suction pipe may have a plurality of branch portions at one end. In this case, both the 1st piping and the 2nd piping may comprise the branching part, and only any one may comprise the branching part.

  The number of auxiliary seal members is not particularly limited. When one auxiliary seal member is provided, the opening of the suction pipe is arranged in a space formed between the main seal member and the one auxiliary seal member. When providing a some auxiliary seal member, the opening of suction piping may be arrange | positioned in the space formed between adjacent auxiliary seal members.

  The present invention can cope with the leakage of the lubricant as quickly as possible, thereby maintaining the cleanliness of the environment where the robot is installed, ensuring the operation reliability of the robot, and appropriately replacing the seal. The present invention is advantageous when applied to an industrial robot having a joint portion in which a mechanical element requiring lubrication is incorporated.

1, 201, 301, 401 Industrial robot 2 Base members 3-8 Arm member 11 Base end side member 21 Front end side member 31 Motor unit 32 Reducer unit 33 Output shaft 41 Main seal member 42 First auxiliary seal member 43 2 Auxiliary seal member 45 Gap 46 Enclosed space 47 First space 48 Second space 50, 250, 350, 450 Leak detector 51, 251, 351, 451 Suction mechanism 52 Lubricant reservoir 52 a Window 53 Pressure sensors 54, 254 354 Detection control unit 55 Alarm 56 Filter 61, 261, 361, 461 Suction piping 61a, 261a, 361a, 461a Opening 62, 262, 362, 462 Negative pressure application pump 263 Fluid supply pump 266, 366 First piping 266a, 366a Openings 267, 367 Second piping 267a, 367a Openings 36 7b Fluid supply port 471 Common part 472 Branch part 472a Opening J Joint part A Rotation axis

Claims (7)

One or more arm members sequentially connected from the base member;
A joint portion that rotatably connects a distal end member of two adjacent members of the base member and the arm member to a proximal end member of the two members;
A mechanical element incorporated into the joint;
A lubricant that lubricates the machine element is sealed by partitioning a gap formed between the distal end side member and the proximal end side member, where the machine element is exposed and communicated with the outside. A main seal member that forms a sealed space;
One or more auxiliary seal members arranged at intervals so as to partition the gap sequentially from the main seal member toward the outside;
A leak detection device for detecting that the lubricant has leaked from the enclosed space into the space between two adjacent seal members of the main seal member and the auxiliary seal member,
The leak detection device includes a suction mechanism for sucking out lubricant from the space for detection of leakage, and the suction mechanism has a suction pipe communicating with the space, and a negative pressure in the space via the suction pipe. An industrial robot, comprising:   The industrial robot according to claim 1, wherein the space between the two adjacent seal members is a space between the main seal member and an auxiliary seal member adjacent to the main seal member.   The leak detection device has a lubricant reservoir for storing the sucked-out lubricant, and the lubricant reservoir is provided outside the joint portion, and has a window portion that allows the inside to be visually recognized. The industrial robot according to claim 1 or 2.   The leak detection device further includes: a pressure sensor that detects an internal pressure of the suction pipe; and a detection control unit that determines that the lubricant has leaked when the internal pressure detected by the pressure sensor increases. Item 4. The industrial robot according to any one of Items 1 to 3.   The industrial robot according to claim 4, wherein a filter medium is provided inside the suction pipe. The suction pipe has a composite pipe structure including a first pipe and a second pipe that forms a passage independent of the first pipe and surrounds the first pipe, and the first pipe and Both of the second pipes communicate with the space,
The negative pressure application device is configured to apply a negative pressure to the space via the first pipe,
The industrial robot according to claim 1, wherein the suction mechanism supplies a fluid into the space through the second pipe during the operation of the negative pressure applying device.   The suction pipe has a plurality of branch portions branched into two or more at one end thereof, and an opening is provided in each of the plurality of branch portions, and the openings are adjacent to each other to define the space. The industrial robot according to any one of claims 1 to 6, wherein the robot is disposed at intervals in a circumferential direction of a seal member on a side close to the enclosed space among the two seal members.

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