JP2011101907A - Scalar robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scalar robot capable of making a vertical shaft suppressing an outflow of an atmosphere of the vertical shaft to an external environment by isolating the atmosphere and the external environment by bellows cope with higher speed vertical movement while maintaining isolation by the bellows. <P>SOLUTION: In the scalar robot, a second arm 15 rotatably provided at a support shaft 14 includes a rising and falling rotary shaft 16 penetrably supported at the second arm 15 to move the second arm 15 in at least an axial direction and the bellows 19 and 20 isolating the rising and falling rotary shaft 16 from the external environment. The scalar robot includes a communicating passage 30 for making the inside of the lower side bellows 20 communicate with the inside of the second arm 15 so that the atmosphere in the lower side bellows 20 provided between a lower end 17 of the rising and falling rotary shaft 16 and a lower part of the second arm 15 may be made to flow into the second arm 15 without being made to flow to the external environment of the lower side bellows 20 when the lower side bellows 20 contracts accompanied by a rise of the rising and falling rotary shaft 16. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a scalar robot.

As an industrial robot, as exemplified in Patent Document 1, a scalar robot (a horizontal articulated robot) in which a plurality of arms constituting the robot is sequentially connected via a horizontal joint is known. The tip of the arm of such a scalar robot is provided with a vertical rotation shaft that is rotationally driven and driven up and down, and the assembly and conveyance of the object can be performed by various hands attached to the vertical rotation shaft. well known.

By the way, as with other industrial robots, a scalar robot is required to have a high operating speed, high processing accuracy, and reliable operation in an external environment according to the production site. Under such circumstances, in recent years, high-speed operation of the scalar robot has been required even in a clean environment such as a clean room where it is not allowed to disperse dust and splashes generated from the scalar robot to the outside environment. Therefore, for example, when using a ball screw for the vertical axis as the vertical axis mechanism of a scalar robot, to prevent dust or oil generated from the vertical drive mechanism or vertical axis of the robot from being scattered in the external environment, A bellows is provided as a protective member. As a result, the vertical axis mechanism is isolated from the outside environment by the bellows, and as a scalar robot, high dust resistance and drip resistance corresponding to a clean environment are ensured.

JP-A-11-170184

However, with an increase in the speed of the scalar robot, the bellows that move up and down with the vertical movement of the vertical axis are also expanded and contracted at high speed, and the pressure fluctuation in the bellows whose volume changes due to the expansion and contraction of the bellows is increasing. In particular, when contracting, the internal pressure of the bellows increases according to the contraction speed, so the pressure inside the bellows becomes higher as the vertical axis speeds up, and the atmosphere inside the bellows becomes an external environment. There is a growing concern about the possibility of a large amount of spillage. Thus, when the air in the bellows flows out, there is a problem that the cleanness of the clean environment is deteriorated.

The present invention has been made in view of such circumstances, and its purpose is to isolate the atmosphere of the vertical axis and the external environment by bellows and suppress the outflow of the atmosphere to the external environment,
It is an object of the present invention to provide a scalar robot that can cope with higher-speed vertical movement while maintaining isolation by bellows.

A scalar robot according to the present invention includes a pivot arm rotatably provided on a base shaft, a spindle that penetrates and supports the pivot arm, and moves at least in the axial direction with respect to the pivot arm; A scalar robot provided with a bellows to be isolated from an environment, wherein an atmosphere in a lower bellows provided between a lower end portion of the main shaft and a lower portion of the rotating arm is changed to the lower position as the main shaft rises. A communication path that connects the inside of the lower bellows and the inside of the rotating arm so as to flow into the inside of the rotating arm without flowing into the outside environment of the lower bellows when the side bellows contracts; The gist.

According to such a configuration, since the atmosphere in the lower bellows flows into the rotating arm through the communication path, even if the lower bellows contracts and the volume decreases,
The excessive atmosphere remaining in the lower bellows becomes a high pressure and is prevented from flowing out to the outside environment. As a result, the atmosphere around the spindle, which may contain dust or splashes of oil, is prevented from flowing out to the outside environment, and the scalar robot is preferably used in a clean environment.

In addition, since the pressure of the atmosphere of the lower bellows that contracts does not increase, the lower bellows contraction speed is increased, that is, even if the vertical movement speed of the spindle is increased, the atmosphere does not flow out to the outside environment. Even in this case, the operation speed of the scalar robot can be increased.

The gist of this scalar robot is that the communication path is provided outside the rotating arm.
According to such a configuration, since the communication path is provided outside the rotating arm, there are few restrictions due to the structure of the arm. That is, since the rotating arm is provided with a large number of supporting mechanisms for supporting the main shaft and driving mechanisms for driving the main shaft, a passage for circulating air between the lower bellows and the rotating arm. It is not easy to secure. As a result, it is possible to easily secure an air flow path between the lower bellows and the rotating arm. In addition, since the communication path is provided outside, application to an existing scalar robot is facilitated.

The scalar robot is characterized in that the communication path is made of a resin material.
According to such a configuration, since the communication path is formed of a resin material, it is easy to adapt the outer shape of the rotating arm and to form a communication path having airtightness suitable for the external environment.

In this scalar robot, an upper bellows communicating with the rotating arm is provided between the upper end portion of the main shaft and the upper portion of the rotating arm, and the atmosphere in the upper bellows and the lower bellows The gist is that the atmosphere can be mutually distributed via the rotating arm.

According to such a configuration, since the upper and lower bellows of the main shaft are communicated with each other, the pressure of the atmosphere in the lower bellows that contracts and increases as the main shaft moves upward is absorbed in the expanded upper bellows. Become so. On the contrary, the lower bellows expanded as the main shaft moves downward absorbs the pressure of the atmosphere in the upper bellows that is contracted and increased. As a result, it becomes possible to prevent the pressure in the bellows from becoming high and to prevent an increase in pressure in the rotating arm.

The gist of this scalar robot is that the atmospheric pressure in the rotating arm is a negative pressure.
According to such a configuration, since the atmospheric pressure in the rotating arm is set to a negative pressure, when the lower bellows is contracted, the atmosphere in the lower bellows is moved more smoothly into the rotating arm. become. Thereby, the possibility that the atmosphere in the lower bellows flows out to the outside environment due to the contraction of the lower bellows is further reduced, and the applicability of the scalar robot to the clean environment is further enhanced.

The front view which shows the front structure of the one Embodiment about the scalar robot concerning this invention. Sectional drawing which shows the operation | movement aspect of the bellows of the scalar robot of the embodiment. Sectional drawing which shows the operation | movement aspect of the bellows of the scalar robot of the embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the front structure of a scalar robot (horizontal articulated robot).
As shown in FIG. 1, the scalar robot is a base 11 as a support body installed on a floor surface or the like.
And a connecting shaft 12 is provided at the upper end of the first arm 13 so that the base end of the first arm 13 can be rotated. The connecting shaft 12 is formed in a columnar shape having an axis C1 and is provided so as to be rotatable around the coaxial core C1 in the base 11, and is rotated forward and reverse by a first motor M1 provided in the base 11. It has come to be. That is, as a result, the first arm 13 rotates in the horizontal direction with respect to the base 11 about the axis C1 of the connecting shaft 12 rotated by the first motor M1.

A support shaft 14 is connected to the distal end portion of the first arm 13 so that the base end portion of the second arm 15 is a rotating body and is rotatably supported. The support shaft 14 is provided so as to be rotatable about the axis C <b> 2 with respect to the second arm 15, and is drivingly connected to a second motor M <b> 2 disposed at the base end portion of the second arm 15. The second motor M2 rotates forward and backward. As a result, the second arm 15 rotates in the horizontal direction with respect to the first arm 13 about the axis C2 as a rotation center by the reaction force of the second motor M2.

The second arm 15 includes a housing portion 15a that maintains the rigidity of the arm 15, and a cover portion 15b that protects equipment provided on the housing portion 15a. A vertical rotation shaft 16 is supported at the distal end portion of the second arm 15 so as to be movable in the vertical direction and to be rotatable as a rotating body. Further, a ball screw nut 21 and a spline nut 22 are provided on the housing portion 15 a at the tip of the second arm 15.

The ball screw nut 21 has the vertical rotation shaft 16 inserted in the center thereof and the vertical rotation shaft 16 based on the rotational power transmitted from the lifting motor M4 provided in the housing portion 15a in the second arm 15. Is moved up and down. On the other hand, the spline nut 22 is vertically rotated based on the rotational power transmitted from the third motor M3 provided in the housing portion 15a in the second arm 15 while the vertical rotation shaft 16 is inserted in the center thereof. The shaft 16 is rotated. In other words, the vertical rotation shaft 16 includes the ball screw nut 21 and the spline nut 22.
Thus, the second arm 15 is supported so as to be rotatable and vertically movable.

A tool such as a hand for gripping the object to be conveyed is attached to the lower end portion 17 of the vertical rotation shaft 16, and various operations on the object can be performed through the tool moved by the rotation and vertical movement. It is supposed to be done.

Next, the internal structure of the tip of the second arm 15 will be described with reference to FIGS. FIG. 2 is a diagram showing a cross-sectional structure of the bellows operation mode when the vertical rotation shaft 16 protrudes upward, and FIG. 3 shows a cross-sectional structure of the bellows operation mode when the vertical rotation shaft 16 projects downward. FIG.

2 and 3, the vertical rotary shaft 16 has a spiral ball screw groove 16 on its outer peripheral surface.
b and spline grooves 16 s parallel to the axis C <b> 3 are respectively formed in a carved shape. The ball screw groove 16b is configured as a female screw for the ball screw nut 21.
The spline groove 16 s is configured as a female thread for the spline nut 22.

That is, the ball screw nut 21 is fixed to the housing portion 15a of the second arm 15, and the vertical rotary shaft 16 is rotatably inserted so that the ball screw groove 16b is screwed into the inside thereof. Further, the inner side of the ball screw nut 21 is rotationally driven by rotational power transmitted from the elevating motor M4 via a belt (not shown) or the like. Thereby, when the inside of the ball screw nut 21 rotates and moves the ball screw groove 16b of the vertical rotation shaft 16 in the vertical direction, the vertical rotation shaft 16 is moved in the vertical direction.

The spline nut 22 is fixed to the nut support portion 18 below the housing portion 15a of the second arm 15, and the vertical rotary shaft 16 can be rotated so that the spline groove 16s is fitted inside the spline nut. It is inserted. The spline nut 22 is rotationally driven by the rotational power transmitted from the third motor M3 via the rotational power transmission mechanism. The rotational power transmission mechanism includes a pulley 23 coupled to the output shaft DS3 of the third motor M3, a pulley 25 of an intermediate shaft 24 installed in parallel near the vertical rotation shaft 16, and the pulleys 23.
, 25, and a timing belt 26. The rotational power transmission mechanism includes a gear 27 supported by the intermediate shaft 24 and connected to the pulley 25, and a gear 28 fixedly connected to the inside of the spline nut 22 with the shaft center C3 as the center of rotation. As a result, the rotational power output from the third motor M3 is transmitted to the inside of the spline nut 22, and when the inside of the spline nut 22 rotates to rotate the spline groove 16s of the vertical rotating shaft 16 in the rotational direction, The rotation shaft 16 is rotated in the rotation direction.

Thus, the housing portion 15a of the second arm 15 holds the third motor M3 and the spline nut 22 while maintaining the rigidity of the third motor M3 and the spline nut 22.
And a transmission mechanism for transmitting rotational power between the upper and lower rotary shafts 1 at the tip thereof.
There are few empty spaces around 6 to support the equipment and maintain rigidity.

The vertical rotation shaft 16 includes an upper bellows 19 between the upper end portion and the cover portion 15b. The upper bellows 19 is formed of a flexible resin or the like so that it can expand and contract. The lower part of the upper bellows 19 is airtight and fixed to the cylindrical part 15H communicating with the cover part 15b. Airtight and fixed to the upper end of the. Thus, the vertical rotation shaft 16
The portion projecting upward from the cover portion 15b of the upper part of the upper bellows 19
It is isolated by. The upper bellows 19 expands and contracts in accordance with the vertical movement of the upper end portion of the vertical rotation shaft 16. For example, when the upper end portion of the vertical rotation shaft 16 extends upward, as shown in FIG. 2, the upper bellows 19 also expands to increase the internal volume, and conversely, the upper end portion of the vertical rotation shaft 16 extends downward. When retreating, as shown in FIG. 3, the upper bellows 19 is reduced and the internal volume is reduced. The increase or decrease in the internal volume of the upper bellows 19 increases or decreases the atmosphere around the vertical rotation shaft 16, but the upper bellows 19 creates an atmosphere around the vertical rotation shaft 16 from within the second arm 15 communicated via the cylindrical portion 15H. Intake can be performed, or the atmosphere around the vertical rotation shaft 16 can be exhausted into the second arm 15.

Further, the upper and lower rotary shaft 16 is provided with a lower bellows 20 between a lower end portion 17 thereof and a nut support portion 18 of the casing portion 15a. Similar to the upper bellows 19, the lower bellows 20 is formed to be stretchable by a flexible resin or the like, and an upper portion thereof is a casing portion 15a.
The lower nut support portion 18 is airtight and fixed, and the lower portion is the lower end portion 1 of the vertical rotation shaft 16.
7 is airtight and fixed. As a result, the portion of the vertical rotating shaft 16 that protrudes downward from the housing portion 15 a is separated from the periphery and the outside environment by the lower bellows 20. The lower bellows 20 expands and contracts in accordance with the vertical movement of the lower end portion 17 of the vertical rotation shaft 16. For example, when the lower end portion 17 of the vertical rotation shaft 16 is retracted upward, as shown in FIG. 2, the lower bellows 20 is reduced to reduce the internal volume, and conversely, the lower end portion 1 of the vertical rotation shaft 16 is reduced.
When 7 extends downward, as shown in FIG. 3, the lower bellows 20 also expands and the internal volume increases. Note that a spline nut 22 is disposed in the nut support portion 18, and air circulation between the lower bellows 20 and the second arm 15 through the nut support portion 18 is not high. In this embodiment, the communication path 30 is provided between the nut support portion 18 and the lower surface of the housing portion 15a to improve the air flow between the lower bellows 20 and the second arm 15. Yes.

That is, a predetermined arcuate vent hole 18H with respect to the axis C3 is formed in the upper side surface of the nut support portion 18 than the lower bellows 20 is connected, and the bottom surface of the housing portion 15a is vented. The openings 32 and 33 are formed, and the communication path 30 is connected to the ventilation holes 18H and the ventilation holes 32 and 3.
3 is in communication with the outside environment. The communication path 30 is formed of a resin material, and the shape of the upper side 30A is formed so as to match the lower surface of the housing portion 15a.
The shape of B is formed so as to fit the ventilation hole 18H, and the lower surface of the housing portion 15a and the ventilation hole 18H are communicated with each other while having airtightness with the outside environment. As a result, when the atmosphere around the vertical rotary shaft 16 becomes excessive due to the reduction in the internal volume of the lower bellows 20, the lower bellows 20 uses the atmosphere inside the vent hole 18H, the communication passage 30 and the vent of the nut support portion 18. The air can be exhausted into the second arm 15 through 32 and 33.
Conversely, when the atmosphere around the vertical rotation shaft 16 decreases due to the increase in the internal volume of the lower bellows 20, the lower bellows 20 changes the atmosphere inside the vents 32 and 33, the communication passage 30 and the nut support portion 18. The air can be sucked from the second arm 15 through the hole 18H.

As a result, even if the lower bellows 20 expands and contracts at a high speed due to the vertical movement of the vertical rotation shaft 16, the pressure inside the lower bellows 20 fluctuates so as to be significantly higher than the pressure in the outside environment. Will be suppressed. If the pressure in the lower bellows 20 is not significantly higher than the pressure in the outside environment, the air tightness between the lower end of the lower bellows 20 and the lower end 17 of the vertical rotating shaft 16 or the upper end of the lower bellows 20 The airtightness between the nut support portion 18 and the nut support portion 18 is suitably maintained, and the possibility that the atmosphere around the vertical rotary shaft 16 flows out to the outside environment is reduced. That is,
Suitable isolation between the lower bellows 20 and the outside environment is maintained.

In addition, vents 34 and 35 are provided on the upper surface of the housing portion 15a and between the cover portion 15b, and the air flow between the housing portion 15a and the cover portion 15b is maintained high. Thereby, the upper bellows 1 in which the increase or decrease in volume occurs in the opposite direction due to the vertical movement of the vertical rotation shaft 16.
9 and the lower bellows 20 are communicated with each other. That is, the exhaust from the upper bellows 19 is sucked into the lower bellows 20, and conversely, the exhaust from the lower bellows 20 is taken into the upper bellows 19.
As a scalar robot, the atmospheric pressure of the second arm 15 is prevented from rising due to the vertical movement of the vertical rotation shaft 16.

As described above, according to the scalar robot of this embodiment, the effects listed below can be obtained.
(1) Since the atmosphere in the lower bellows 20 flows into the second arm 15 through the communication path 30, even if the lower bellows 20 contracts and the volume decreases,
It is possible to suppress the excessive atmosphere remaining in the lower bellows 20 from becoming a high pressure and flowing out to the outside environment. As a result, the atmosphere around the vertical rotation shaft 16 that may contain dust or oil splashes is prevented from flowing out to the outside environment, and the scalar robot is suitably used in a clean environment.

(2) Since the pressure of the atmosphere of the lower bellows 20 that contracts does not increase, even if the contraction speed of the lower bellows 20 is increased, that is, when the vertical movement speed of the vertical rotation shaft 16 is increased, the atmosphere remains outside. Therefore, the operation speed of the scalar robot can be increased even in a clean environment.

(3) Since the communication path 30 is provided outside the second arm 15, there are few restrictions due to the structure of the arm when the communication path 30 is installed. That is, since the second arm 15 is provided with a number of drive mechanisms such as a support mechanism for supporting the vertical rotation shaft 16 and a ball screw nut 21 and a spline nut 22 for driving the vertical rotation shaft 16. It is not easy to secure a passage for allowing air to flow between the lower bellows 20 and the second arm 15. As a result, an air flow path between the lower bellows 20 and the second arm 15 can be easily secured. Further, since the communication path 30 is provided outside, application to an existing scalar robot is facilitated.

(4) Since the communication path 30 is made of a resin material, it is easy to form the communication path 30 that is suitable for the outer shape of the second arm 15 and has airtightness suitable for the external environment.
(5) Since the upper and lower bellows 19 and 20 of the vertical rotation shaft 16 are communicated, the pressure of the atmosphere in the lower bellows 20 contracted as the vertical rotation shaft 16 moves upward is expanded in the upper bellows 19 Will be absorbed. On the contrary, the inside of the lower bellows 20 expanded as the vertical rotation shaft 16 moves downward absorbs the pressure of the atmosphere in the upper bellows 19 that is contracted.
As a result, it becomes possible to prevent the pressure in the bellows 19 and 20 from becoming high, and to prevent an increase in pressure in the second arm 15.

(6) Since the atmospheric pressure in the second arm 15 is set to a negative pressure, when the lower bellows 20 is contracted, the atmosphere in the second bellows 20 is moved more smoothly into the second arm 15. I made it. Thereby, the possibility that the atmosphere in the lower bellows 20 flows out to the outside environment due to the contraction of the lower bellows 20 is further reduced, and the applicability of the scalar robot to the clean environment is further enhanced.

In addition, the said embodiment can also be implemented in the following aspects, for example.
In the above embodiment, the case where the vent hole 18H is formed in a predetermined arc shape with respect to the axis C3 is exemplified, but the present invention is not limited to this, and the pressure inside the lower bellows is set to a pressure that can maintain airtightness. If possible, the shape of the vent hole may be circular or elliptical, and the number thereof may be one or two or more.

-In above-mentioned embodiment, although the case where the exhaust_gas | exhaustion of the lower bellows 20 was collect | recovered by the 2nd arm 15 was illustrated, not only this but the inside of a 2nd arm may be maintained at the negative pressure. According to this, the exhaust of the lower bellows is more preferably moved to the second arm.

DESCRIPTION OF SYMBOLS 11 ... Base, 12 ... Connection shaft, 13 ... 1st arm, 14 ... Support shaft as a base shaft, 15 ...
A second arm as a rotating arm, 15a ... a housing part, 15b ... a cover part, 15H ... a cylinder part,
16: Vertical rotary shaft as the main shaft, 16b: Ball screw groove, 16s: Spline groove, 17 ...
Lower end, 18 ... Nut support, 18H ... Vent hole, 19 ... Upper bellows, 20 ... Lower bellows, 21 ... Ball screw nut, 22 ... Spline nut, 23,25 ... Pulley, 24 ... Intermediate shaft, 26 ... Timing Belt, 27, 28 ... gear, 30 ... communication path, 30A ... upper side, 30
B: shaft side, 32 to 35 ... vent, M1 ... first motor, M2 ... second motor, M3 ... third
Motor, M4 ... Lifting motor, DS3 ... Output shaft.

Claims (5)

A pivot arm rotatably provided on a base shaft includes a main shaft penetrating and supported by the pivot arm and moving at least in the axial direction with respect to the pivot arm, and a bellows that isolates the main shaft from an external environment. A scalar robot provided,
The atmosphere in the lower bellows provided between the lower end portion of the main shaft and the lower portion of the rotating arm is caused to flow to the outside environment of the lower bellows when the lower bellows contracts as the main shaft rises. A scalar robot comprising: a communication path that allows the lower bellows and the rotation arm to communicate with each other so as to flow into the rotation arm. The scalar robot according to claim 1, wherein the communication path is provided outside the rotating arm. The scalar robot according to claim 1, wherein the communication path is made of a resin material. An upper bellows communicating with the rotating arm is provided between the upper end portion of the main shaft and the upper portion of the rotating arm,
The scalar robot according to any one of claims 1 to 3, wherein an atmosphere in the upper bellows and an atmosphere in the lower bellows can be circulated through the rotating arm. The scalar robot according to any one of claims 1 to 3, wherein the atmospheric pressure in the rotating arm is a negative pressure.

Images