JP2011218488A - Joint structure - Google Patents

Abstract

The present invention contributes to miniaturization of a joint structure.
A joint structure 1 according to the present invention includes a first arm part 110, a second arm part 120 rotatably connected to the first arm part 110, and a second arm part 120. And a hollow pulley 130 for transmitting a driving force from the driving device 5. A cutout portion 131 a in which the wiring 9 is accommodated is formed on the outer peripheral portion 131 of the hollow pulley 130. As a result, the wiring 9 can be arranged almost in the plane region of the belt 11, so that it is not necessary to shake the wiring largely outward as in the prior art, and the joint structure can be downsized. Therefore, workability in a narrow space such as a drawer or a refrigerator can be improved.
[Selection] Figure 1

Description

  The present invention relates to a joint structure.

  Conventionally, as a joint structure such as a robot arm, as disclosed in Patent Documents 1 to 6, a technique for reducing the exposure of wiring arranged around the arm portion has been disclosed. That is, in the joint structures of Patent Documents 1 to 6, the wiring is accommodated in the arm portion from the outside of the rotating portion of the arm portion. In particular, in the joint structure of Patent Document 1, a hollow pulley that transmits a driving force from a driving device is connected to an arm portion, and wiring is stored in the arm portion from the outside of the arm portion via the hollow portion of the hollow pulley. is doing.

JP 11-151689 A JP-A-11-170184 JP-A-2005-66718 JP 2006-7355 A Japanese Patent No. 3848123 Japanese Patent Publication No. 5-36197

  In the joint structures of Patent Documents 1 to 6, wiring is accommodated in the arm portion from the outside of the rotating portion of the arm portion. At this time, when the hollow pulley is connected to the arm portion as in the joint structure of Patent Document 1, the wiring is routed from the outside of the arm portion so that the wiring does not contact the hollow pulley, and the wiring is connected to the hollow pulley. Pass through the hollow. For this reason, the wiring greatly protrudes outward from the rotating portion of the arm portion, resulting in an increase in the size of the joint structure.

  An object of the present invention is to solve such a problem, and contributes to miniaturization of the joint structure.

  The joint structure according to the present invention includes a first arm portion, a second arm portion rotatably connected to the first arm portion, and a driving force from a driving device to the second arm portion. And a hollow pulley for transmitting a wire, and a notch for receiving wiring is formed in an outer peripheral portion of the hollow pulley. As a result, since the wiring can be arranged almost in the plane area of the belt that transmits the driving force to the hollow pulley, it is not necessary to shake the wiring largely outward as in the prior art, and the joint structure can be downsized. it can. Therefore, when the joint structure is used for a robot arm, workability in a narrow space such as a drawer or a refrigerator can be improved. Furthermore, since a notch part is formed in a hollow pulley, it contributes to the weight reduction of a hollow pulley. In addition, since the wiring is simplified, the joint structure can be covered with a simple configuration.

  The hollow pulley is connected to the output shaft of the second arm portion, and the output shaft of the second arm portion is formed with a hollow portion continuous with the hollow portion of the hollow pulley, and the hollow pulley is cut. It is preferable that the wiring housed in the notch portion is passed through the hollow portion of the hollow pulley and the hollow portion of the second arm portion. As a result, the wiring hardly twists or hangs down even when the second arm portion rotates. Therefore, the life of the wiring can be extended.

  It is preferable that the first arm portion includes a wiring passage portion that allows the wiring to pass from one side portion of the first arm portion to the other side portion.

  It is preferable that a friction reducing member for reducing friction with the wiring is provided on the surface of the hollow pulley. Thereby, the lifetime of wiring can be prolonged.

  As described above, according to the present invention, the joint structure can be reduced in size.

It is a figure which shows the example of application of the joint structure of embodiment which concerns on this invention. It is a perspective view which shows the joint structure of embodiment which concerns on this invention. It is a horizontal sectional view showing roughly the joint structure of the embodiment concerning the present invention. It is a figure which shows the arrangement | positioning relationship between a notch part and wiring in the joint structure of embodiment which concerns on this invention. It is a figure which shows the arrangement | positioning relationship between a notch part and wiring in the joint structure of embodiment which concerns on this invention. It is a horizontal sectional view showing roughly a joint structure of a different embodiment concerning the present invention.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

  The joint structure 1 according to the present embodiment is applied to the wrist of a robot arm 2 as shown in FIG. As shown in FIGS. 2 and 3, the joint structure 1 includes a first arm portion 110, a second arm portion 120, and a hollow pulley 130.

  The first arm part 110 is a flat plate member. As shown in FIG. 3, a ring-shaped connecting portion 111 is formed at one end of the first arm portion 110 so as to be substantially orthogonal to the flat plate portion. The connecting portion 111 of the first arm portion 110 is rotatably connected to the base portion 210 via the bearing 3. That is, the first arm part 110 has a rotation center O <b> 1 in a direction orthogonal to the base part 210. However, the rotation direction of the first arm unit 110 is not particularly limited.

  A through hole is formed in the other end portion of the first arm portion 110, and the bearing 4 is fitted into the through hole. A hollow pulley 130 is disposed on one side of the bearing 4. A second arm portion 120 is disposed on the other side of the bearing 4. A rotation shaft 121 of the second arm portion 120 is passed through the bearing 4. That is, the second arm portion 120 has a rotation center O2 in a direction orthogonal to the first arm portion 110.

  On the side surface of the first arm portion 110 on the side where the second arm portion 120 is disposed, the electric motor 5 that is a driving device is disposed. That is, the reduction gear 6 that amplifies the driving torque of the electric motor 5 is provided in the vicinity of one end of the first arm portion 110 so as to penetrate therethrough. At this time, the input shaft of the reduction gear 6 is disposed on the side where the electric motor 5 is disposed with the first arm portion 110 interposed therebetween. The rotation shaft of the electric motor 5 is connected to the input shaft of the reduction gear 6. On the other hand, the output shaft of the reduction gear 6 is disposed on the side where the hollow pulley 130 is disposed with the first arm portion 110 interposed therebetween. A pulley 7 is connected to the output shaft of the reduction gear 6.

  A through hole 8 is formed as a wiring passage portion at a position between the bearing 4 and the reduction gear 6 in the first arm portion 110. As shown in FIG. 3, a wiring 9 extending from the base 210 is passed through the through hole 8. The wiring 9 passing through the through hole 8 is arranged on the side where the pulley 7 is arranged from the side where the electric motor 5 is arranged across the first arm part 110.

  The second arm portion 120 is also a flat plate member. A rotating shaft 121 is formed at one end of the second arm portion 120. The rotating shaft 121 is passed through the bearing 4. As a result, the second arm portion 120 is coupled to the first arm portion 110 so as to be rotatable about the rotation center O2. In the second arm portion 120, a hollow portion 121 a is formed on the rotation shaft 121. As shown in FIG. 1, a robot hand 2a is connected to the other end of the second arm portion 120. The second arm unit 120 is provided with a control device 10 for the robot hand 2a, for example.

  The hollow pulley 130 is connected to the rotation shaft 121 of the second arm unit 120. The belt 11 is passed between the hollow pulley 130 and the pulley 7. As a result, the rotational driving force of the electric motor 5 is transmitted to the hollow pulley 130 via the reduction gear 6, the pulley 7, and the belt 11. A hollow portion 130 a is formed in the hollow pulley 130 so as to be continuous with the hollow portion 121 a of the rotating shaft 121 in the second arm portion 120.

  Further, a cutout portion 131 a in which the wiring 9 is accommodated is formed on the outer peripheral portion 131 of the hollow pulley 130. That is, as shown in FIG. 3, the wiring 9 is disposed on the side where the hollow pulley 130 is disposed with the first arm portion 110 interposed therebetween through the through hole 8 of the first arm portion 110. . Then, the wiring 9 is passed through the hollow portion 130a of the hollow pulley 130 and the hollow portion 121a of the rotating shaft 121 in the second arm portion 120 through the notch 131a of the hollow pulley 130, and the control device 10. Connected to. As a result, the wiring 9 can be disposed substantially in the plane area of the belt 11, so that it is not necessary to shake the wiring 9 outward as in the prior art, and the joint structure can be downsized. Therefore, when the joint structure 1 is used for a robot arm as in the present embodiment, workability in a narrow space such as a drawer or a refrigerator can be improved. Furthermore, since the notch 131a is formed in the hollow pulley 130, it contributes to weight reduction of the hollow pulley 130. Further, since the handling of the wiring 9 is simplified, the joint structure can be covered with a simple configuration.

  At this time, since the wire 9 is once passed through the hollow portion 130a of the hollow pulley 130 and the hollow portion 121a of the rotating shaft 121 in the second arm portion 120, the wire 9 is connected to the control device 10, so Even if the second arm portion 120 is rotated, it hardly twists or hangs down. Therefore, the life of the wiring 9 can be extended.

  Here, as shown in FIGS. 4 and 5, the notch 131 a is preferably formed so that the wiring 9 does not contact the outer peripheral portion 131 of the hollow pulley 130 when the hollow pulley 130 rotates. As a result, the life of the wiring 9 can be extended. Incidentally, FIG. 4 shows the positional relationship between the notch 131a and the wiring 9 when the rotation angle of the second arm 120 is 0 °. . FIG. 5 shows an arrangement relationship between the notch 131a and the wiring 9 when the second arm 120 is rotated by 45 ° in the direction of arrow A. That is, the formation region of the notch 131 a depends on the rotation angle of the hollow pulley 130. At this time, if it is desired to ensure a large rotation angle of the second arm portion 120, the rotation angle of the hollow pulley 130 is inevitably large, and therefore the notch 131a needs to be formed large. In this case, the rotation angle of the second arm portion 120 is ensured to be large by increasing the diameter of the pulley 7 and decreasing the winding angle θ of the belt 11 around the hollow pulley 130 compared to the diameter of the hollow pulley 130. be able to.

  In order to reduce friction between the hollow pulley 130 and the wiring 9 when the hollow pulley 130 rotates, a friction reducing member 12 may be provided on the surface of the hollow pulley 130 as shown in FIG. preferable. The friction reducing member 12 may be provided at least in a region surrounded by a line connecting the rotation center O2 of the hollow pulley 130 and the end of the notch 131a. Thereby, the lifetime of the wiring 9 can be further prolonged.

The embodiment of the joint structure according to the present invention has been described above. However, the present invention is not limited to the above configuration, and can be changed without departing from the technical idea of the present invention.
In the said embodiment, although the joint structure is applied to the wrist part of a robot arm, the location applied is not specifically limited.
In the above embodiment, the pulleys are connected to each other by a belt, but may be connected by a wire or a chain.
In the above embodiment, the wiring 9 is connected to the control device, but the element to which the wiring 9 is connected is not particularly limited. Therefore, the wiring 9 may be an air supply line, a signal line, or a power supply line.

DESCRIPTION OF SYMBOLS 1 Joint structure 2 Robot arm, 2a Robot hand 5 Electric motor 6 Reduction gear 7 Pulley 8 Through hole 9 Wiring 10 Controller 11 Belt 12 Friction reduction member 110 1st arm part 111 Connection part 120 2nd arm part, 121 rotation Shaft, 121a hollow part 130 hollow pulley, 130a hollow part 131 outer peripheral part, 131a notch part 210 base

Claims (4)

A first arm part;
A second arm portion rotatably connected to the first arm portion;
A hollow pulley that transmits a driving force from a driving device to the second arm portion,
A joint structure characterized in that a cutout portion for accommodating a wiring is formed on an outer peripheral portion of the hollow pulley. The hollow pulley is connected to the output shaft of the second arm portion;
The output shaft of the second arm portion is formed with a hollow portion continuous with the hollow portion of the hollow pulley,
2. The joint structure according to claim 1, wherein the wiring housed in the cutout portion of the hollow pulley is passed through the hollow portion of the hollow pulley and the hollow portion of the second arm portion.   The joint according to claim 1, wherein the first arm portion includes a wiring passage portion that allows the wiring to pass from one side portion to the other side portion of the first arm portion. Construction.   The joint structure according to any one of claims 1 to 3, wherein a friction reducing member that reduces friction with the wiring is provided on a surface of the hollow pulley.

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