Robot air purge mechanism, robot, and robot air purge method

Abstract

This air purge mechanism (30) comprises: a plurality of containers (10, 25) for housing electrical connection parts; and a cable (16) that connects between the containers (10, 25). One of the containers (10) has formed therein an air supply port for supplying compressed air into the container (10). The cable (16) comprises: a wire bundle in which a group of wires connected to the electrical connection parts are bundled; and a sheath that covers the exterior surface of the wire bundle. The respective interior spaces of the two containers (10, 25) are connected to each other via gaps between the wires inside the sheath.

Description

Technical Field

[0001] The present disclosure relates to Of the robot an air purge mechanism, a robot, and Of the robot an air purge method.

Background Art

[0002] Conventionally, a structure has been known for preventing outside air from coming into contact with an electric motor of a robot (see, for example, Patent Document 1). The structure of Patent Document 1 is an explosion-proof structure for preventing external flammable gas from coming into contact with the electric motor. This structure houses the electric motor in a sealed container, provides a header for supplying a non-flammable protective gas to the base of the robot, connects the sealed container and the header with a tube, and houses a wiring cable in the tube.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a structure in which sealed containers are connected by an air supply tube and a cable is disposed in the tube, it is necessary to prepare a tube having an inner diameter slightly larger than the outer diameter of the cable. In particular, the operation of inserting the cable into the tube is not easy, and the manufacturing cost is high. Further, when a movable cable is disposed in the tube, the flexibility of the movable cable including the tube becomes lower than that of the movable cable alone.

[0005] In addition, in an environment with high humidity where water vapor and liquid droplets fall, it is necessary to prevent condensation from occurring due to outside air entering the vicinity of electrical components such as the motors of the robot. Therefore, it is desired to prevent outside air from entering the vicinity of the electrical components without increasing the wiring space and cost of the cable and without reducing the durability.

Means for Solving the Problems

[0006] One aspect of the present disclosure includes a plurality of containers that house electrical connection parts and a cable that connects between the containers. One of the containers is provided with an air supply port for supplying pressurized air into the container. The cable includes a wiring bundle that bundles a group of wirings connected to the electrical connection parts and a sheath that covers the outer surface of the wiring bundle. The spaces in two of the containers are interconnected by the gaps between the wirings in the sheath. Of the robot It is an air purge mechanism.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Mode for Carrying Out the Invention

[0008] The air purge mechanism 30, the robot 1, and the air purge method according to the first embodiment of the present disclosure will be described below with reference to the drawings. The robot 1 according to the present embodiment is, for example, a vertical six-axis articulated robot, and as shown in FIGS. 1 and 2, includes a base 2 fixed to an installation surface such as a floor surface, and a movable part 3 that is moved relative to the base 2.

[0009] The movable part 3 includes a swivel body 4 rotatably supported about a first axis A with respect to the base 2. Further, the movable part 3 includes a first arm 5 rotatably supported with respect to the swivel body 4 about a second axis B disposed in a plane orthogonal to the first axis A, and a second arm 6 rotatably supported about a third axis C parallel to the second axis B. Furthermore, the movable part 3 includes a three-axis wrist unit 7 at the tip of the second arm 6.

[0010] The robot 1 includes a first motor that rotates the swivel body 4 with respect to the base 2, a second motor that rotates the first arm 5 with respect to the swivel body 4, a third motor that rotates the second arm 6 with respect to the first arm 5, and fourth, fifth, and sixth motors that operate the wrist unit 7. Only the fourth motor 8 is shown in FIG. 3. The first motor is disposed inside the base 2. The second motor is disposed inside the swivel body 4. The inside of the base 2 and the inside of the swivel body 4 communicate with each other and are sealed from the outside.

[0011] The third motor is housed inside the second arm 6. As shown in FIG. 3, the fourth motor 8 is fixed to the second arm 6 and is sealed from the outside by a sealed container formed by the second arm 6 and a cover 9 attached to the second arm 6.

[0012] The wrist unit 7 is rotatable with respect to the second arm 6 in a state of being sealed from the second arm 6 by a rotation seal member (not shown). Thereby, the second arm 6 and the wrist unit 7 constitute a sealed container sealed from the outside. The fifth motor and the sixth motor are housed in the wrist unit 7.

[0013] As shown in FIG. 4, a distribution box (container) 10 is fixed to the base 2. The distribution box 10 constitutes a rectangular parallelepiped box-shaped sealed container sealed from the outside. On the outer surface of the distribution box 10, a connector 11 to which a cable (not shown) extending from a control device (not shown) can be connected is arranged.

[0014] The connector 11 is fixed at a position closing a through hole (not shown) penetrating one side wall 10a of the distribution box 10 in the plate thickness direction. Inside the distribution box 10, wirings 12 are respectively connected to a plurality of terminals (electrical connection portions, not shown) of the connector 11 arranged inside the distribution box 10 by soldering.

[0015] As shown in FIG. 4, each wiring 12 is bundled for each connection destination, and a plurality of wiring bundles are covered with sheaths 13 on the outer surfaces to form a plurality of cables 14, 15, 16, 17, 18. The cables penetrate the other side wall 10b of the distribution box 10 arranged at a position closing the opening 19 of the base 2 and are led into the base 2. Each sheath 13 is made of, for example, an electrically insulating and water-resistant material such as PVC (polyvinyl chloride).

[0016] Each of the cables 14, 15, 16, 17, 18 is fixed to the side wall 10b of the distribution box 10 through a plurality of through holes 10c penetrating the side wall 10b of the distribution box 10 in the plate thickness direction by a known cable gland 20, and is fixed to the side wall 10b of the distribution box 10 in a state of penetrating the through holes 10c. The cable gland 20 can seal the gap around the outer surface of the sheath 13 by tightening the nut, and can fix the cables 14, 15, 16, 17, 18 so as not to move in the longitudinal direction and the circumferential direction by the friction between the outer surface of the sheath 13 and the cable gland 20.

[0017] The cables 14, 15, 16, 17, 18 penetrating the side wall 10b of the distribution box 10 by the cable gland 20 include a first cable 14 connected to the first motor, a second cable 15 connected to the second motor, and a third cable 16 connected to the third to sixth motors. Further, the cables 14, 15, 16, 17, 18 penetrating the side wall 10b of the distribution box 10 by the cable gland 20 include a fourth cable 17 connected to a battery 23 to be described later, a signal line 21 for the user, and a fifth cable 18 including an air tube 22.

[0018] As shown in FIG. 4, the robot 1 includes a battery 23 for data holding. The battery 23 is detachable from the side surface of the base 2 and is housed in a battery container (container) 24 disposed inside the base 2 in a sealed state. Further, as shown in FIGS. 1 and 2, the robot 1 includes a distribution box (container) 25 at the rear end of the second arm 6.

[0019] The robot 1 according to the present embodiment includes an air purge mechanism 30. The air purge mechanism 30 includes a plurality of containers such as a distribution box 10, a battery container 24, a distribution box 25, a cover 9, and a second arm 6, and cables 14, 15, 16, 17, 18 connecting these containers.

[0020] In the distribution box 10, as an electrical connection part, the soldered part between the terminal of the connector 11 and the wiring 12 is accommodated. In the battery container 24, as an electrical connection part, the connection part between the terminal of the battery 23 and the wiring 12 by a screw is accommodated. As shown in FIG. 5, on one wall surface 25a of the distribution box 25, the third cable 16 that covered the wiring bundles for the third to sixth motors together with the sheath 13 penetrates through the through hole 25c and is fixed in a state sealed by the cable ground 20.

[0021] Inside the distribution box 25, the wirings 12 for the third to sixth motors exposed from one end of the sheath 13 of the third cable 16 are branched into wiring bundles bundled for each motor. Three of the wiring bundles are shown in FIG. 5.

[0022] Also, on the other wall surface 25b of the distribution box 25, the branch cables 26, 27, 28, 29 for the third to sixth motors penetrate through the through holes 25d and are each fixed in a state sealed by the cable ground 20. Each of the branch cables 26, 27, 28, 29 is configured by covering the outer surface of the wiring bundle for the third to sixth motors with the sheath 13. Each of the branch cables 26, 27, 28, 29 is respectively connected to a plurality of wiring bundles of the third cable 16 by a connector 31.

[0023] That is, in the distribution box 25, as an electrical connection part, a connector 31 for detachably connecting the wiring 12 of the third cable 16 and the wiring 12 of the branch cables 26, 27, 28, 29 is accommodated. Among the branch cables 26, 27, 28, 29 fixed to the distribution box 25, the branch cable 27 for the fourth motor 8 penetrates through the through hole 9c provided in the cover 9 and is fixed to the cover 9 in a state where the cable ground 20 seals the space between the sheath 13 and the through hole 9c.

[0024] The branch cable 27 fixed to the cover 9 is connected by a connector 32 to the fourth motor 8 which is hermetically accommodated in the cover 9, with the wiring 12 for the fourth motor 8 exposed from the end face of the sheath 13 in the space within the cover 9. That is, a connector 32 for connecting to the fourth motor 8 is accommodated in the cover 9 as an electrical connection part.

[0025] Similarly, the other branch cables 26, 28, 29 fixed to the distribution box 25 penetrate through a plate 33 that hermetically closes an opening 34 provided in the second arm 6 as shown in FIG. 6, and are fixed to the plate 33 by a cable ground 20. The plate 33 is detachably fixed to the outer surface of the second arm 6 by screws with a gasket (not shown) interposed therebetween.

[0026] The tip of one branch cable 26 fixed to the plate 33 is connected in the space inside the second arm 6 to the third motor, with the wiring 12 for the third motor exposed from the end face of the sheath 13 hermetically accommodated in the space inside the second arm 6.

[0027] Also, the tips of the other branch cables 28, 29 fixed to the plate 33 are connected in the space inside the wrist unit 7 to the fifth motor and the sixth motor, with the wiring 12 for the fifth motor and the sixth motor hermetically accommodated in the space inside the wrist unit 7. That is, connectors for connecting to the third, fifth, and sixth motors are also accommodated as electrical connection parts in the spaces inside the second arm 6 and the wrist unit 7.

[0028] As shown by way of example in FIG. 7, each of the cables 14, 15, 16, 17, 18 includes a wiring bundle in which a group of wirings 12 are bundled together, and a sheath 13 that covers the wiring bundle so as to be in close contact with the outer surface of the wiring bundle. Each wiring 12 has, for example, a circular cross-sectional shape, and gaps are formed between the wirings 12 in the bundled wiring bundle. The sheath 13 is shaped so as to clamp the wiring bundle from the radially outer side, and the covering of each wiring 12 is compressed in the radial direction but does not enter the gaps between the wirings 12. As a result, gaps extending over the entire length in the longitudinal direction of the cables 14, 15, 16, 17, 18 are formed between the group of wirings 12 constituting the wiring bundle within the sheath 13 of each of the cables 14, 15, 16, 17, 18.

[0029] The space inside the distribution box 10 is connected to the space inside the branch box 25 and the space inside the battery container 24 through the gaps formed in the third cable 16 and the fourth cable 17, respectively. Further, the space inside the branch box 25 is connected to the space inside the cover 9 and the space inside the second arm 6 and the wrist unit 7 through the gaps formed in the branch cables 26, 27, 28, 29, respectively.

[0030] The distribution box 10 is also provided with a tube joint (air supply port) 35 to which a tube extending from an external air pressure supply source is detachably connected. By connecting the tube to the tube joint 35, pressurized air supplied from the air pressure supply source via the tube can be supplied into the space inside the distribution box 10.

[0031] In this embodiment, as shown in FIG. 8, a rectangular frame-shaped spacer 36 equivalent to the contour of the connector 11 is disposed between the connector 11 of the distribution box 10 and the side wall 10a that fixes the connector 11. A tube joint 35 is fastened to a screw hole 37 penetrating the side wall 10a in the spacer 36. The space between the spacer 36 and the side wall 10a and the space between the spacer 36 and the connector 11 are sealed by a gasket (not shown). The inner opening of the spacer 36 has a size that allows the connector 11 with the wiring 12 connected to the terminal to pass through it with a proper orientation.

[0032] The air purge mechanism 30 and the air purge method using the robot 1 according to this embodiment configured as described above will be described below. The air purge method according to this embodiment includes connecting the spaces in the distribution box 10, the distribution box 25, the battery container 24, the cover 9, the second arm 6, and the wrist unit 7 by the third cable 16, the fourth cable 17, and the branch cables 26, 27, 28, 29, and supplying dry air to the distribution box 10.

[0033] Specifically, a tube led from a dry air supply device disposed outside is connected to a tube joint 35 provided in the spacer 36 of the distribution box 10, and dry air is supplied via the tube. The dry air supply device is, for example, a device that removes dust and moisture in the air supplied from an air supply source provided in a factory.

[0034] When the dry air supplied via the tube is supplied into the distribution box 10 via the tube joint 35, the pressure in the distribution box 10 is increased. The internal space of the distribution box 10 is connected to the internal spaces of the battery container 24 and the distribution box 25 via the gaps in the sheaths 13 of the third cable 16 and the fourth cable 17. Thereby, the dry air supplied into the distribution box 10 is supplied to the internal spaces of the battery container 24 and the distribution box 25 via the gaps.

[0035] Also, the space inside the distribution box 25 is connected to the space inside the cover 9, the space inside the second arm 6, and the space inside the wrist unit 7 via the gaps inside the sheaths 13 of the branch cables 26, 27, 28, 29. As a result, the dry air supplied into the distribution box 25 is supplied to the spaces inside the cover 9, the second arm 6, and the wrist unit 7 via the gaps.

[0036] As a result, the spaces inside the battery container 24, the distribution box 25, the cover 9, the second arm 6, and the wrist unit 7 are filled with pressurized dry air, so that the entry of external water vapor and the like into these spaces can be blocked. And by keeping the humidity of the spaces inside the battery container 24, the distribution box 25, the cover 9, the second arm 6, and the wrist unit 7 low, the occurrence of condensation inside the spaces can be prevented, and the occurrence of short - circuit and rust of the electrical connection parts can be prevented.

[0037] In this case, according to the present embodiment, since the gap formed between the wirings 12 inside the sheath 13 is used as the passage for the dry air, there is no need to provide a separate tube for forming a flow path around each of the cables 14, 15, 16, 17, 18. Therefore, it is possible to prevent an increase in the wiring space due to a tube that is slightly larger in diameter than the outer diameters of the cables 14, 15, 16, 17, 18.

[0038] Also, the operation of inserting the cables 14, 15, 16, 17, 18 into the tube is unnecessary, and the manufacturing cost can be kept low. Furthermore, it is possible to prevent a decrease in flexibility due to the arrangement of the tube outside the cables 14, 15, 16, 17, 18. In particular, there is an advantage that the ease of deformation of a movable cable such as the third cable 16 can be maintained, and the durability of the cables 14, 15, 16, 17, 18 can be maintained.

[0039] Further, according to the robot 1 according to the present embodiment, when it is not necessary to fill the spaces inside the battery container 24, the distribution box 25, the cover 9, the second arm 6, and the wrist unit 7 with dry air, it is not necessary to supply dry air to the power distribution box 10. In this case, the tube joint 35 for connecting the tube from the dry air supply device is unnecessary, and the tube joint 35 may be removed together with the spacer 36.

[0040] That is, if the robot 1 used in an environment where air purge is unnecessary is regarded as a standard robot, a robot used in an environment where air purge is necessary can be configured with a minimum modification of retrofitting the spacer 36 with the tube joint 35 attached. Therefore, regardless of the presence or absence of air purge, there is an advantage that many parts can be shared, and the time and cost related to the modification can be reduced.

[0041] In the present embodiment, a vertical six-axis articulated robot is exemplified as the robot 1, but the present invention is not limited thereto, and it can be applied to any other type of robot. Further, as the containers for performing air purge with dry air, the power distribution box 10, the battery container 24, the distribution box 25, the cover 9, the second arm 6, and the wrist unit 7 are exemplified, but the present invention is not limited thereto. For example, it may be applied to an electric component attached to an arm or a wrist by a user, such as a solenoid valve or a container or a cover for housing a motor for driving a tool.

[0042] Further, for example, a pressure sensor for detecting the pressure inside the distribution box 25 may be attached to the distribution box 25, or a tube joint (pressure detection port) to which the pressure sensor can be attached as needed may be provided. Thereby, when an abnormality such as a hole opening in the sheaths 13 of the cables 14, 15, 16, 17, 18 occurs, this can be detected as a pressure drop, and it can be confirmed whether the air purge is surely performed.

[0043] In this case, if the pressure sensor has a communication means and the pressure is lower than a predetermined threshold value, it may be notified to that effect by the control device or other notification means. The pressure sensor or the pressure detection port may be provided in any one of the other containers 24, 25 other than the distribution box 10.

[0044] Also, in the present embodiment, each of the cables 14, 15, 16, 17, 18 is attached to the container by the cable gland 20. In this case, since the sheath 13 of the cables 14, 15, 16, 17, 18 is tightened from the outer surface by the cable gland 20, it is conceivable that the gap between the wirings 12 is reduced and the air flow cross-sectional area is decreased. Therefore, as shown in FIG. 9, the cables 14, 15, 16, 17, 18 may include one or more tubes 38 in the wiring bundle, or as shown in FIG. 10, a reinforcing tube 39 made of a rigid material for securing a gap only in the portion tightened by the cable gland 20 may be inserted and arranged. Also, the branch cables 26, 27, 28, 29 may similarly include one or more tubes 38 in the wiring bundle, or the reinforcing tube 39 may be inserted and arranged only in the portion tightened by the cable gland 20.

[0045] Also, in the present embodiment, pressurized air is supplied into the distribution box 10, but instead, an inert gas such as pressurized nitrogen gas may be supplied. Also, although the dry air supply device is arranged outside the robot 1, the dry air supply device may be attached to the distribution box 10. Thereby, by simply passing the pressurized air supplied from the pneumatic supply source of the factory through the dry air supply device, the pressurized air used for air purging can be dehumidified and dried.

[0046] Also, instead of the spacer 36, the distribution box 10 may be provided with a screw hole that can be opened and closed by a plug or the like, and when the supply of dry air is required, the tube joint 35 may be attached to the screw hole with the plug removed. Also, although the cables 14, 15, 16, 17, 18 were to be attached to the respective containers 6, 7, 9, 10, 24, 25 by the cable gland 20, as shown in FIG. 11, they may be connected by a connector 40 that has a waterproof function only when fitted and allows the spaces within the sheaths 13 of the cables 14, 15, 16, 17, 18 to communicate with each other.

[0047] Specifically, the connector 40 includes a first housing 41 attached to each of the containers 6, 7, 9, 10, 24, 25, a second housing 42 attached to the cable gland 20, an O-ring 43 disposed between the first housing 41 and the second housing 42, and contacts 46, 47 having connection portions 44, 45 to which the wirings 12 are respectively connected on one end side to the first housing 41 and the second housing 42. When the pin-shaped contact 47 is inserted inside the cylindrical contact 46, the contacts 46 and 47 are adapted to fit together.

[0048] Thereby, when the first housing 41 and the second housing 42 are fitted, the O-ring 43 disposed between the first housing 41 and the second housing 42 is compressed and the first housing 41 and the second housing 42 are brought into close contact, so that the connector 40 has its interior sealed and is waterproof against the outside. Also, since the spaces between the contacts 46, 47 and the first housing 41 and the second housing 42 are not sealed, it is possible to supply the pressurized air supplied through the space within the sheath 13 into each of the containers 6, 7, 9, 10, 24, 25 through the respective gaps inside the connector 40. Here, there are gaps between a plurality of components inside the connector 40, or holes in the components due to manufacturing or other reasons.

Explanation of Reference Numerals

[0049] 1 Robot 2 Base 3 Movable Part 10 Distribution Box (Container) 12 Wiring 13 Sheath 14, 15, 16, 17, 18 cables 24 Battery container (container) 25 Distribution box (container) 30 Air purge mechanism 31 Connector (electrical connection part) 35 Tube joint (air supply port)

Claims

1. A plurality of containers for housing electrical connection parts, and a cable for connecting between the containers, and one of the containers is provided with an air supply port for supplying pressurized air into the container, and the cable includes a wiring bundle bundling a group of wirings connected to the electrical connection parts, and a sheath covering the outer surface of the wiring bundle, and An air purge mechanism of a robot in which spaces in two of the containers are interconnected by a gap between the wirings in the sheath.

2. The air purge mechanism of the robot according to claim 1, wherein the container is a sealed container.

3. The air purge mechanism of the robot according to claim 2, wherein a pressure detection port or a pressure sensor for detecting the pressure inside the container is provided in any one of the containers not provided with the air supply port.

4. The air purge mechanism of the robot according to any one of claims 1 to 3, further comprising a dry air supply device connected to the air supply port.

5. A base fixed to the installation surface, a movable part provided movably with respect to the base, and an air purge mechanism according to any one of claims 1 to 4, and one of the containers provided with the air supply port is fixed to the base, and A robot in which the other container not provided with the air supply port is fixed to the movable part.

6. Connecting between a plurality of containers for housing electrical connection parts by a cable including a wiring bundle bundling a group of wirings connected to the electrical connection parts and a sheath covering the outer surface of the wiring bundle, Supplying pressurized air into one of the containers, and An air purge method of a robot for supplying the pressurized air supplied into the one container to the other containers via a gap between the wirings in the sheath of the cable.

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