JP4464073B2 - Robot joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joint structure of a robot in which one arm body is connected to the other arm body so as to be conically rotatable.
[0002]
[Prior art]
6 to 8 are cross-sectional views showing joint structures 16 to 18 of a conventional robot. The prior art robot rotates the second arm body 2 conically around the tilt axis L3 with respect to the first arm body 1 by the motor 7 held by the first arm body 1. The inclination axis L3 is inclined at a predetermined angle with respect to the axes L1 and L2 of the first and second arm bodies.
[0003]
The robot has a communication body 8 that connects the first arm body 1 and the second arm body 2. The communicating body 8 is fixed to the second arm body 2 and is provided so as to be rotatable around the tilt axis L3 with respect to the first arm body 1. The communication body 8 is formed with a communication hole 5 extending along the inclined axis L3. The communication hole 5 communicates the internal space 3 of the first arm body and the internal space 4 of the second arm body. In the robot, a cable 6 extending from the internal space 3 of the first arm body through the communication hole 5 to the internal space 4 of the second arm body is disposed (see, for example, Patent Document 1 and Patent Document 2).
[0004]
[Patent Document 1]
JP-A-56-163624
[Patent Document 2]
Japanese Patent Laid-Open No. 10-225881
[0005]
[Problems to be solved by the invention]
The joint structures 16 and 17 of the prior art robot shown in FIGS. 6 and 7 transmit the rotational force from the motor 7 to the communication body 8 by the spur gear pairs 11 and 12. The motor 7 extends parallel to the tilt axis L3. That is, as the motor 7 moves away from the communicating body 8 in the axial direction A along the axis L1 of the first arm body, the motor 7 intersects the axis L1 of the first arm body 1 in the axial direction A of the first arm body 1. To go away.
[0006]
Therefore, as in the prior art shown in FIG. 6, when the first arm body 1 and the second arm body 2 have the same outer peripheral shape, the motor 7 may protrude outward from the first arm body 1. 7, when the motor 7 is built in the first arm body 1, the outer peripheral shape of the first arm body 1 may be larger than the outer peripheral shape of the second arm body 2.
[0007]
In the prior art shown in FIG. 8, the rotational force from the motor 7 is transmitted to the output unit 10 of the communication body 8 by the bevel gear pairs 13 and 14. Of the bevel gear pairs 13, 14, one bevel gear 13 is an external bevel gear provided on the motor 7, and the other bevel gear 14 is an internal bevel gear 14 provided on the inner peripheral portion of the communication body 8. It is. As a result, the external bevel gear 13 closes the communication hole 5, and there is a problem that a sufficient space for accommodating the cable 6 cannot be secured.
[0008]
Accordingly, an object of the present invention is to provide a joint structure of a robot that can reduce the outer peripheral shape of an arm body and can sufficiently secure a space for accommodating an insertion body such as a cable.
[0009]
[Means for Solving the Problems]
The present invention includes a cylindrical first arm body,
A cylindrical second arm body;
It extends along the axis of the first arm body and is held in the first arm body. motor When,
A first communication hole is formed to communicate the internal space of the first arm body and the internal space of the second arm body. The first communication hole is fixed to the second arm body and is arranged around an inclination axis that is inclined with respect to the axis of each arm body. A communicating body provided rotatably with respect to one arm body;
motor A first transmission body provided in
A second transmission body provided in the communication body, wherein a second communication hole is formed to communicate the first communication hole and the internal space of the first arm body;
The second transmission body forming the opening of the second communication hole is retracted from the space near the opening where the opening of the second transmission body faces and intersects the inclined axis, and the rotational force of the first transmission body is applied to the second transmission body. A joint structure of a robot including an intermediate transmission body for transmission.
[0010]
According to the present invention, the direction in which the rotational force is transmitted can be converted by using each transmission body. motor Is In the first arm It arrange | positions along the axis line of a 1st arm body. Therefore motor Compared to the case where is arranged in parallel to the tilt axis, in a virtual plane perpendicular to the axis of the first arm body motor The occupied area can be reduced. by this motor The outer periphery shape of the 1st arm body which incorporates can be made as small as possible.
[0011]
When an insertion object such as a cable is inserted through each arm body, the insertion object extends from the communication hole to the space near the opening and extends from the space near the opening to the open space on the opposite side of the intermediate transmission body. Since the intermediate transmission body is retracted from the space in the vicinity of the opening, the intermediate transmission body does not block the communication hole and the space in the vicinity of the opening, and a sufficient space for the inserted material to be accommodated in the first arm body is secured. can do.
[0012]
Further, by using the intermediate transmission body, the degree of freedom of the rotational force that can be transmitted to the communication body can be expanded. This allows existing communicators and motor It is not necessary to greatly change the torque and the rotational speed necessary for rotating the arm body.
[0013]
Further, the present invention is characterized in that the intermediate transmission body decelerates the rotational force of the first transmission body and transmits it to the second transmission body.
[0014]
According to the present invention, through the intermediate transmission body, motor A torque larger than the torque generated by is transmitted. For example, when the torque to be transmitted to the second arm body is set, motor Even if the generated torque is small, the set torque can be applied to the second arm body. in this way motor Because the torque generated can be reduced, motor Can be reduced, and as a result, the outer peripheral shape of the first arm body can be reduced.
[0015]
In the present invention, the first transmitter is motor A first gear fixed to the
The second transmission body has a second gear fixed to the communication body,
The intermediate transmission body has a first intermediate gear that meshes with the first gear, a second intermediate gear that meshes with the second gear, and a gear shaft that coaxially connects the first intermediate gear and the second intermediate gear. It is characterized by.
[0016]
According to the present invention, a rotational force with a large torque can be transmitted by transmitting the rotational force via the gear. Further, the rigidity of the rotational force transmission system can be increased as compared with belt transmission and the like, and the arm body can be rotated with high accuracy even when the torque to be transmitted is large. Also, by adjusting the gear ratio between the first intermediate gear and the first gear and the gear ratio between the second intermediate gear and the second gear, motor The torque and rotational speed of the generated rotational force can be easily converted, and the converted rotational force can be transmitted to the communicating body.
[0017]
In the present invention, the first axis angle formed by the axis of the first gear and the axis of the first intermediate gear is selected to be 90 degrees or less, and the second axis formed by the axis of the second gear and the axis of the second intermediate gear. The angle is chosen to be over 90 degrees,
The first and second gears and the first and second intermediate gears are respectively composed of external bevel gears, and the first intermediate gear is farther away from the tilting axis in the intersecting direction than the second intermediate gear and is inclined. It is characterized by being arranged on the same side in the crossing direction as the second intermediate gear with respect to the axis.
[0018]
According to the present invention, the gear shaft is inclined in the direction away from the communication body in the tilt axis direction as it is moved away from the communication body in the crossing direction. The first intermediate gear is disposed at a position farther from the space near the opening than the second intermediate gear. As a result, the gear shaft and the second intermediate gear can be arranged at positions away from the communicating body, and a large space for accommodating the insertion object can be secured. In addition, the first gear can be arranged at a position retracted from the communicating body in the axial direction of the first arm body, and a large space for accommodating the insertion object can be secured.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view schematically showing a joint structure 20 of a robot according to an embodiment of the present invention. The robot is an articulated robot having first and second arm bodies 21 and 22. The robot bends the second arm body 22 with respect to the first arm body 21 and moves the object provided on the second arm body 22.
[0020]
The robot includes a first arm body 21, a second arm body 22, a speed reducer 26, a rotation transmission mechanism 24, and a rotation drive source 25 as a joint structure. Each arm body 21 and 22 is formed in a cylindrical shape, and internal spaces 30 and 31 are formed. The arm bodies 21 and 22 are coupled to each other around the inclined axis L3 so as to be rotatable.
[0021]
The rotation axis L3 is inclined with respect to the axis L1, L2 of each arm body 21, 22. Accordingly, the second arm body 22 can be conically rotated with respect to the first arm body 21. That is, the second arm body 22 rotates around the tilt axis L3 about the intersection S between the axis L2 of the second arm body and the tilt axis L3. In the present invention, the rotation includes a case of angular displacement.
[0022]
Each arm body 21, 22 incorporates a cable 23, which is an insert, in the internal spaces 30, 31. The cable 23 is inserted through the second arm body 22 from the first arm body 21 and extends along the arrangement direction of the arm bodies 21 and 22. The cable 23 has flexibility and is provided so as to be deformable as the second arm body 22 rotates. The cable 23 is a cable for electrical wiring, for example.
[0023]
The rotational drive source 25 has a columnar outer shape. The rotational drive source 25 extends in the axial direction A of the first arm body and is disposed in the internal space 30 of the first arm body 21. Specifically, the rotational drive source 25 has an axis L25 extending coaxially, parallel, or substantially parallel to the axis L1 of the first arm body. The rotation drive source 25 is realized by a servo motor and has a rotation shaft 25a. The rotational drive source 25 is connected to the control device, and rotationally drives the rotary shaft 25a based on a command from the control device.
[0024]
The speed reducer 26 shown in FIG. 1 is shown in a simplified manner for easy understanding. The speed reducer 26 also serves as an articulated body for connecting the arm bodies 21 and 22, and connects the arm bodies 21 and 22 so as to be rotatable around the tilt axis L3.
[0025]
The reduction gear 26 is formed in a hollow cylindrical shape and is provided coaxially with the tilt axis L3. The speed reducer 26 is a communication body in which a first communication hole 33a that connects the internal space 30 of the first arm body and the internal space 31 of the second arm body is formed. The first communication hole 33a extends coaxially along the tilt axis L3.
[0026]
The speed reducer 26 includes a holding portion 27, an input portion 28, and an output portion 29, which are formed in a cylindrical shape centered on the tilt axis L3. The holding unit 27 is fixed to the first arm body 21, and the output unit 29 is fixed to the second arm body 22. The input unit 28 and the output unit 29 are supported by the holding unit 27 and are provided to be rotatable around the tilt axis L3. The input unit 28 is at least partially disposed in the internal space of the first arm body 21. Moreover, the input part 28 and the output part 29 are connected so that a rotational force can be transmitted mutually.
[0027]
The rotational force transmitted to the input unit 28 is amplified by a predetermined amplification ratio, and the rotational speed is decelerated by a predetermined reduction ratio and transmitted from the output unit 29 to the second arm body 22. . The second arm body 22 to which the rotational force is transmitted rotates with respect to the first arm body 21 around the tilt axis L3. Such a reduction gear 26 is realized by a hollow wave gear mechanism, for example, a harmonic drive (registered trademark).
[0028]
The rotation transmission mechanism 24 converts the rotational force generated by the rotational drive source 25 into a rotational force that rotates about the tilt axis L <b> 3 and transmits the rotational force to the input unit 28 of the speed reducer 26. The rotation transmission mechanism 24 includes a first transmission body 40, a second transmission body 41, and an intermediate transmission body 42. The first transmission body 40 transmits the rotational force generated by the rotational drive source 25 to the intermediate transmission body 42. The intermediate transmission body 42 converts the rotational force transmitted from the first transmission body 40 into a rotational force that rotates around the tilt axis L <b> 3 and transmits the rotational force to the second transmission body 41. The second transmission body 41 transmits the rotational force transmitted from the intermediate transmission body 42 to the input unit 28 of the speed reducer 26.
[0029]
The rotation transmission mechanism 24 transmits the rotational force using a plurality of gears. The first transmission body 40 includes a first gear 46 that is fixed coaxially with the rotation shaft 25 a of the rotation drive source 25. The first gear 46 is formed with a plurality of teeth over the entire circumference in the circumferential direction of the rotary shaft 25a.
[0030]
The second transmission body 41 has a second gear 47 that is coaxially fixed to the input portion 28 of the speed reducer 26. The second gear 47 has an inner diameter equal to or larger than the inner diameter of the first communication hole 33a and is formed in a cylindrical shape. As a result, the second gear 47 is formed with a second communication hole 33b that communicates the first communication hole 33a with the internal space 30 of the first arm body, and the second communication hole 33b is an inner portion larger than the first communication hole 33a. It has a circumference. Further, the second gear 47 is formed with a protruding portion 47a protruding outward in the radial direction over the entire circumference in the circumferential direction of the input portion 28, and a plurality of teeth are formed over the entire circumferential direction of the protruding portion 47a.
[0031]
The intermediate transmission body 42 includes a first intermediate gear 43, a second intermediate gear 44, and a gear shaft 45. The first intermediate gear 43 meshes with the first gear 46 and is formed so as to be able to transmit rotational force. The second intermediate gear 44 meshes with the second gear 47 and is formed so as to be able to transmit rotational force. The gear shaft 45 connects the first intermediate gear 43 and the second intermediate gear 44 coaxially, and is rotatably supported by the first arm body 21. The first gear pair 48 constituted by the first gear 46 and the first intermediate gear 43 constitutes an external bevel gear pair. Similarly, the second gear pair 49 constituted by the second gear 47 and the second intermediate gear 44 also constitutes an external bevel gear pair.
[0032]
Such an intermediate transmission body 42 is retracted from the near-opening space 32 and arranged. The near-opening space 32 is a space where the opening of the second gear 47 that forms the opening of the second communication hole 33b faces. The size of the opening vicinity space 32 is determined by the bending state of the cable 23 that has come out of the second communication hole 33b. Even if the cable 23 is most deformed, the opening vicinity space 32 is set to a size such that the cable 23 and the intermediate transmission body 42 do not come into contact with each other. In other words, the intermediate transmission body 42 is disposed at a position retracted from the deformable range of the cable 23.
[0033]
The cable 23 is inserted through the first and second communication holes 33a and 33b and extends from the second communication hole 33b to the near-opening space 32. Further, the cable 23 extends from the near-opening space 32 to the open space 34 opposite to the intermediate transmission body 42 and extends along the axial direction A of the first arm body. The cable 23 is locked in a state where flexibility is maintained by a locking piece 50 provided on each arm body 21, 22. This prevents the cable 23 from being greatly deformed in the arm body. Even if the cable 23 is deformed with the rotation of the second arm body 22, the locking piece 50 locks the cable 23 so that the cable 23 does not move toward the intermediate transmission body 42 beyond the space near the opening 32.
[0034]
FIG. 2 is a side view showing the rotation transmission mechanism 24 according to the embodiment of the present invention. FIG. 3 is a side view showing the rotation transmission mechanism 124 of the first comparative example. FIG. 4 is a side view showing the rotation transmission mechanism 224 of the second comparative example. About the structure of the 1st comparative example corresponding to one Embodiment of this invention, 100 is added and attached to the reference symbol of one Embodiment. The configuration of the second comparative example corresponding to the embodiment of the present invention is given by adding 200 to the reference numeral of the embodiment.
[0035]
The rotation drive source 25 extends in parallel or substantially in parallel with the axial direction A along the axis L1 of the first arm body, and preferably extends coaxially with the axis L1 of the first arm body. The rotational drive source 25 is disposed at a predetermined distance away from the speed reducer 26 along the axial direction A of the first arm body.
[0036]
When the inclination angle α at which the inclination axis L3 is inclined with respect to the virtual axis L4 parallel to the axis L1 of the first arm body is determined, the first axis angle γ that is the axis angle of the first gear pair 48, and the second The second shaft angle β which is the shaft angle of the gear pair 49 is selected by the following relational expression.
α = 180− (β + γ)
[0037]
Here, α is an inclination angle, γ is a first axis angle, and β is a second axis angle.
[0038]
As shown in FIG. 2, in the present embodiment, the first axis angle γ is selected to be 90 degrees or less, and the second axis angle β is selected to be 90 degrees or more. Further, the first intermediate gear 43 is separated from the second intermediate gear 44 in the intersecting direction B with respect to the tilt axis L3 with respect to the tilt axis L3 and further away from the second intermediate gear 44 in the intersecting direction B intersecting the tilt axis L3. Arranged on the same side. As a result, the gear shaft 45 extends away from the speed reducer 26 in the crossing direction B with respect to the inclined axis L3 as it moves away from the first arm body in the axial direction A.
[0039]
In the first comparative example, the first axis angle γ is selected to exceed 90 degrees, and the second axis angle β is selected to be less than 90 degrees. The first intermediate gear 143 is closer to the intersecting direction B than the second intermediate gear 144 with respect to the tilt axis L3, and is disposed on the same side as the second intermediate gear 144 with respect to the tilt axis L3.
[0040]
In the second comparative example, the first axis angle γ is selected to be less than 90 degrees, and the second axis angle β is selected to be less than 90 degrees. The first intermediate gear 243 is disposed on the opposite side to the second intermediate gear 244 in the intersecting direction B with respect to the tilt axis L3.
[0041]
In the present embodiment, as shown in FIG. 2, the first intermediate gear 43 is disposed at a position farther away from the near-opening space 32 in the intersecting direction B than the second intermediate gear 44. Further, the gear shaft 45 does not need to protrude from the second intermediate gear 44. Accordingly, the first intermediate gear 43 and the gear shaft 45 can be arranged at positions away from the speed reducer 26. In addition, the extended space obtained by extending the first and second communication holes 33a and 33b in the direction along the inclined axis L3 is not blocked by the first intermediate gear 43 and the gear shaft 45, and can be a space that can accommodate the cable 23. It can be secured greatly.
[0042]
In contrast, in the first comparative example shown in FIG. 3, the extension space is blocked by the first intermediate gear 143, and the opening vicinity space 132 cannot be enlarged. Further, in the second comparative example shown in FIG. 4, the extension space is blocked by the gear shaft 245, and a large space that can accommodate the cable 23 cannot be secured.
[0043]
In the embodiment of the present invention, the first intermediate gear 43 and the second intermediate gear 44 are arranged on the same side in the cross direction B with respect to the tilt axis L3. Thereby, the side opposite to the side where the second intermediate gear 44 is disposed in the opening vicinity space 32 can be opened. As a result, the cable 23 can be disposed along the inclined axis L3. Further, by forming the open side of the near-opening space 32 on the extended line side of the inclined axis L3 with respect to the axis L1 of the first arm body, the cable 23 is disposed on the first arm body 21 without being largely bent. be able to.
[0044]
Thus, by selecting the first shaft angle γ and the second shaft angle β as shown in the embodiment of the present invention, the first intermediate gear 43 and the gear shaft 45 are prevented from blocking the extension space, and the cable A large space for accommodating 23 can be secured. Further, by arranging the first intermediate gear on the same side in the intersecting direction B with the second intermediate gear 44 with respect to the inclined axis L3, the arranged cable 23 does not have to be greatly bent.
[0045]
For example, when the inclination angle is 15 degrees, the first gear pair 48 is selected such that the module is 1.5 and the first shaft angle γ is 45 degrees. The second gear pair 49 has a module of 1.5, and its second shaft angle β is selected to be 120 degrees. Further, the number of teeth of the driving gear 46 is selected as 16, and the number of teeth of the first intermediate gear 43 is selected as 24. The number of teeth of the second gear 47 is selected as 32, and the number of teeth of the second intermediate gear 44 is selected as 24. By using such a rotation transmission mechanism, a torque 2.4 times the torque that can be generated by the rotation drive source 25 can be transmitted to the input unit 28 of the speed reducer. Further, the torque transmitted to the second arm body is further amplified by the speed reducer 26. For example, the reduction gear 26 outputs a torque 100 times the torque transmitted to the input unit 28 from the output unit 29 and transmits the torque to the second arm body 22.
[0046]
A specific example of such a joint structure is an exemplification, and the outer peripheral diameters of the arm bodies 21 and 22, the torque and rotational speed necessary for rotating the second arm body 22, the thickness of the cable 23, the cable The optimum shape is selected according to the design conditions such as 23 flexibility.
[0047]
As described above, according to the embodiment of the present invention, the rotational force generated by the rotational drive source 25 is transmitted through the first transmission body 40, the intermediate transmission body 42, and the second transmission body 41 in order. 26 to the input unit 28. As a result, the second arm body 22 receives a rotational force that rotates about the tilt axis L3 with respect to the first arm body 21, and rotates about the tilt axis L3 with respect to the first arm body 21.
[0048]
By using each of the transmission bodies 40, 41, 42, the direction in which the rotational force is transmitted can be changed. In the present invention, the rotational drive source 25 is disposed along the axis L1 of the first arm body. Therefore, compared with the prior art shown in FIG. 6 and FIG. 7, the area occupied by the rotational drive source 25 in the virtual plane perpendicular to the axis L1 of the first arm body can be reduced, and the outer peripheral shape of the first arm body 21 Can be made as small as possible.
[0049]
In order to reduce the outer peripheral shape of the first arm body 21, it is necessary to reduce the size of the rotational drive source 25. However, when the motor is downsized, it is necessary to increase the reduction ratio of the rotational force transmitted from the rotational drive source 25 to the reduction gear 26 in order to obtain the torque necessary for rotating the second arm body 22. .
[0050]
When the first transmission body 40 and the second transmission body 41 are directly connected, in order to obtain a necessary reduction ratio, the first transmission body 40 or the second transmission body is enlarged and the first arm body 21 is enlarged. The outer peripheral shape of the will become large. In the embodiment of the present invention, by using the intermediate transmission body 42, the individual gears of the first and second transmission bodies 40 and 41 can be downsized to obtain a necessary reduction ratio. In other words, the necessary torque can be transmitted to the speed reducer 26 using the small first and second transmission bodies 40 and 41 and the small rotational drive source 25, and the outer peripheral shape of the first arm body 22 is reduced in size. be able to.
[0051]
Further, there is no need to perform a special control operation of the rotational drive source 25, the speed reducer 26, and the rotational drive source 25, and the rotational force generated by the rotational drive source 25 is suitable for the rotational force to be transmitted to the second arm body 22. It can be easily converted into rotational force. As a result, the existing speed reducer 26 and the rotational drive source 25 can be used, and it is not necessary to greatly change the torque and rotational speed of the rotational drive source 25 required for rotating the second arm body 22.
[0052]
Further, by using the intermediate transmission body 42, the degree of freedom of the arrangement position where the rotation drive source 25 can be arranged can be expanded, and the rotation drive source 25 can be arranged close to the axis L1 of the first arm body. . By making the rotational drive source 25 as close as possible to the axis L1 of the first arm body 21, the outer peripheral shape of the first arm body 21 can be made smaller. Further, the rotational drive source 25 can be retracted from the speed reducer 26 in the axial direction A of the first arm body, and the space near the opening 32 can be formed large.
[0053]
The cable 23 extends from the second communication hole 33 b to the near-opening space 32 and extends from the near-opening space 32 to the open space 34 on the opposite side of the intermediate transmission body 42 in the cross direction B. By arranging the intermediate transmission body 42 so as to be retracted from the near-opening space 32, even if the cable 23 is deformed in the near-opening space, it is possible to prevent the cable 23 and the intermediate transmission body 42 from contacting each other.
[0054]
Further, a torque larger than the torque generated by the rotation drive source 25 is transmitted to the speed reducer 26 by the rotation transmission mechanism 24. When the torque to be transmitted to the second arm body 22 is determined in advance, the torque to be generated by the rotation drive source 25 can be reduced, and consequently the rotation drive source 25 can be reduced in size. Therefore, the outer peripheral shape of the first arm body 21 incorporating the rotation drive source 25 can be further reduced. Further, by using the intermediate transmission body 42, a large torque can be transmitted without increasing the size of the first transmission body 40 and the second transmission body 41, and the first and second arm bodies 21 and 22 can be transmitted. Can be formed in substantially the same outer peripheral shape.
[0055]
Moreover, a rotational force with a large torque can be transmitted by transmitting the rotational force via the gear. Further, the rigidity of the power transmission system can be increased as compared with belt transmission, and the second arm body 22 can be accurately rotated even when the torque to be transmitted is large. Further, by adjusting the gear ratio between the first intermediate gear 43 and the first gear 46 and the gear ratio between the second intermediate gear 44 and the second gear 47, the torque generated by the rotary drive source 25 is amplified. It can be transmitted to the output unit 28 of the speed reducer 26.
[0056]
Further, by selecting the first shaft angle γ and the second shaft angle β as shown in the embodiment, the first intermediate gear 43 and the gear shaft 45 cause the first and second communication holes 33a and 33b to be inclined axis L3. The extended space extended along the line is not blocked, and a large space for accommodating the cable 23 can be secured. Further, the first intermediate gear 43 can be easily arranged on the same side in the intersecting direction B with the second intermediate gear 44 with respect to the inclined axis L3, and the cable 23 does not have to be greatly bent. As a result, the cable 23 can be more reliably accommodated in the first arm body. Further, the teeth of the second gear 47 are formed on the protruding portion 47a protruding outward in the radial direction of the input portion 28, so that the space near the opening 32 can be further increased.
[0057]
Further, in a virtual plane including the tilt axis L3 and the axis L1 of the first arm body, a virtual line extending in the tilt axis direction from the intersection S toward the second arm body, and an axis of the first arm body from the intersection S toward the first arm body The intermediate transmission body 42 is arranged in a region where the angle around the intersection S is small in a region divided into two by a virtual line formed by a virtual line extending in the direction A. As a result, the first gear 46 and the second gear 47 can be connected at a short distance, and the occupied volume of the intermediate transmission pair 42 can be reduced.
[0058]
The configuration of the present invention as described above is an example of the invention, and the configuration can be changed within the scope of the invention. For example, when the rotational force from the rotational drive source 25 is transmitted to the second arm body 22 via the speed reducer 26, when it is not necessary to transmit a large torque, the rotational force is transmitted without using the speed reducer 26. May be. Further, although the gear transmission mechanism is used as the rotation transmission mechanism 24, another transmission mechanism may be used. For example, in the embodiment, the rotation transmission mechanism 24 is realized by using two gear pairs 48 and 49, but another spur gear pair, a bevel gear pair, a belt transmission mechanism including a belt and a pulley, a rack and a pinion, The torque transmission mechanism which consists of may be included. Further, rotation transmission may be performed by two or more gear pairs. Further, the tilt axis L3 and the first arm axis L1 may not be arranged on the same plane.
[0059]
In the present embodiment, it is assumed that the second arm body 22 rotates around the tilt axis L3 with respect to the first arm body 21. As another embodiment, when a rotational force is transmitted to the second arm body 22, the first arm body 21 may rotate around the tilt axis L <b> 3 with respect to the second arm body 22 by a reaction force. .
[0060]
FIG. 5 is a cross-sectional view showing a part of a wind tunnel test support device 300 in which the joint structure 20 of the robot of the present invention is used. The wind tunnel model support device 300 supports the test model 327 so that the posture can be changed in the wind tunnel in which the airflow 324 is formed in a predetermined flow direction. The wind tunnel model support apparatus 300 includes first to fourth arm bodies 340, 341, 333, and 334 and first to third arm bodies 335, 336, and 337.
[0061]
The first arm body 340 supports the test model 327 on the downstream side in the flow direction with respect to the test model 327 and has a predetermined first axis L301. The second arm body 341 supports the first arm body 340 so as to be rotatable around the first axis L301 on the downstream side in the flow direction with respect to the first arm body 340.
[0062]
The third arm body 333 is downstream of the second arm body 341 in the flow direction 324 and rotatably supports the second arm body 341 around a second axis L302 inclined with respect to the first axis L301. The third axis L303 is inclined with respect to the second axis L302. The fourth arm body 334 supports the third arm body rotatably around the third axis L3 on the downstream side in the flow direction with respect to the third arm body 333.
[0063]
Each of the rotational drive sources 335 to 337 is incorporated in any of the rotational drive sources. The first rotational drive source 335 rotationally drives the first arm body 340 around the first axis L301 with respect to the second arm body 341. The second rotational drive source 336 rotationally drives the second arm body 341 around the second axis L302 with respect to the third arm body 333. The third rotational drive source 337 rotationally drives the third arm body 333 around the third axis L303 with respect to the fourth arm body 334.
[0064]
The wind tunnel model test apparatus 300 further includes a support body that supports the fourth arm body 337 and a relative displacement rotation drive source that drives the support body to perform relative displacement in three directions orthogonal to each other. By adjusting the posture of the test model 327 mainly by the first to third rotation driving sources 335 to 337 and adjusting the position of the test model 327 mainly by the relative displacement rotation driving source, the position and posture of the test model 327 are adjusted. Can be adjusted.
[0065]
The test model 327 is connected to detection means 329 for detecting the state of the test model 327. The measurement result measured by the detection unit 329 is transmitted to the measurement result processing device 356 through the state signal cable 344. Further, a power supply cable 345 and a drive amount transmission cable 346 are connected to each of the rotational drive sources 335 to 337.
[0066]
Each of these cables 344 to 346 becomes an insertion object that passes through the internal spaces 361, 363, and 365 of each arm body. Each cable 344 to 346 is arranged to be able to pass through the internal space of each arm body even when each arm body rotates.
[0067]
The first to third rotational drive sources 335 to 337 and the cables 44, 45, and 46 are built in any one of the arm bodies and do not protrude from the outer peripheral surface of each arm body. Thereby, the outer shape of each arm body can be formed in a sharp shape along the flow direction of the airflow. Therefore, the wind tunnel model support apparatus 300 can be brought close to a streamlined shape, and the turbulence of the airflow caused by the rotation drive sources 335 to 337 and the cables 344 to 346 can be eliminated.
[0068]
The wind tunnel model support apparatus 300 has the joint structure 20 of the robot according to an embodiment of the present invention with respect to the joint structure that transmits the rotational force from the second rotational drive source 336 to the second arm body 361. Thereby, the outer peripheral shape of the second arm body 333 can be reduced in size. Therefore, the airflow state in the wind tunnel test can be brought close to a realistic airflow state, and the measurement accuracy of the wind tunnel test can be improved.
[0069]
Further, the joint structure 20 of the robot of the present invention can be used other than the wind tunnel model support device 300. For example, the robot having the joint structure 20 of the robot of the present invention can reduce the outer peripheral shape of the arm body, so that the occupied area can be reduced, and interference with other devices and wall surfaces is prevented. be able to. This makes it possible to widen the movable region even in a narrow work space. Moreover, the joint structure 20 of the robot of the present invention may be provided in some joint structures among the robots having a plurality of joint structures.
[0070]
【The invention's effect】
As described above, according to the first aspect of the present invention, the outer peripheral shape of the first arm body can be made as small as possible. As a result, the occupation area of the robot can be reduced, and interference with other devices and walls can be prevented and the movable area can be expanded.
[0071]
Moreover, since the accommodation space for accommodating the insert can be sufficiently secured, even when the insert is thick, it can be reliably accommodated in the first arm body. Further, even when the radius of curvature at which the insert is curved is small, it can be accommodated. Further, it is possible to prevent the inserted article and the intermediate transmission body from coming into contact with each other, thereby preventing the robot from being damaged.
[0072]
In addition, existing communicators and motor Since the torque and the rotational speed are not significantly changed, the convenience can be improved and the manufacturing can be performed at a low cost.
[0073]
According to the present invention as set forth in claim 2, motor The torque generated can be reduced, motor Can be miniaturized. Therefore, the outer peripheral shape of the first arm body can be further reduced in size.
[0074]
According to the third aspect of the present invention, a large torque torque can be transmitted by transmitting the torque via the gear. Therefore, even when the torque required for rotating the arm body is large, the arm body can be rotated with high accuracy. Also, by adjusting the gear ratio between the first intermediate gear and the first gear and the gear ratio between the second intermediate gear and the second gear, motor It is possible to easily change the torque and the rotation speed of the rotational force generated by the transmission force and transmit the changed rotational force to the communication body.
[0075]
Moreover, according to this invention of Claim 4, a gear shaft, a 2nd intermediate | middle gear, and a 1st gear can be arrange | positioned in the position away from the communicating body, and it can ensure large space which can accommodate an insertion thing. it can. This prevents the insert from coming into contact with the gear shaft, the second intermediate gear, and the first gear, thereby preventing damage to the robot.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a joint structure of a robot according to an embodiment of the present invention.
FIG. 2 is a side view showing a rotation transmission mechanism 24 according to an embodiment of the present invention.
FIG. 3 is a side view showing a rotation transmission mechanism 124 of a first comparative example.
FIG. 4 is a side view showing a rotation transmission mechanism 224 of a second comparative example.
FIG. 5 is a cross-sectional view showing a part of a wind tunnel test support apparatus 300 in which the joint structure of the robot of the present invention is used.
FIG. 6 is a cross-sectional view showing a joint structure which is a first prior art robot.
FIG. 7 is a cross-sectional view showing a joint structure which is a second prior art robot.
FIG. 8 is a cross-sectional view showing a joint structure which is a third prior art robot.
[Explanation of symbols]
20 Robot joint structure
21 First arm body
22 Second arm body
23 Cable
24 Rotation transmission mechanism
25 Rotation drive source
26 Reducer
28 Input section
29 Output section
30 Internal space of the first arm body
31 Internal space of the second arm body
32 Space near the opening
33a First communication hole
33b Second communication hole
40 First transmission body
41 Second transmitter
42 Intermediate transmission
43 1st intermediate gear
44 Second intermediate gear
45 Gear shaft
46 1st gear
47 Second gear
48 First gear pair
49 Second gear pair
L1 Axis of first arm body
L2 Axis of second arm body
L3 tilt axis
L25 Axis of rotation drive source

Claims (4)

A cylindrical first arm body;
A cylindrical second arm body;
A motor extending along the axis of the first arm body and held in the first arm body;
A first communication hole is formed to communicate the internal space of the first arm body and the internal space of the second arm body. The first communication hole is fixed to the second arm body and is arranged around an inclination axis that is inclined with respect to the axis of each arm body. A communicating body provided rotatably with respect to one arm body;
A first transmission body provided in the motor ;
A second transmission body provided in the communication body, wherein a second communication hole is formed to communicate the first communication hole and the internal space of the first arm body;
The second transmission body forming the opening of the second communication hole is retracted from the space near the opening where the opening of the second transmission body faces and intersects the inclined axis, and the rotational force of the first transmission body is applied to the second transmission body. A joint structure of a robot comprising an intermediate transmission body for transmission.   The joint structure of the robot according to claim 1, wherein the intermediate transmission body decelerates the rotational force of the first transmission body and transmits it to the second transmission body. The first transmission body has a first gear fixed to the motor ,
The second transmission body has a second gear fixed to the communication body,
The intermediate transmission body has a first intermediate gear that meshes with the first gear, a second intermediate gear that meshes with the second gear, and a gear shaft that coaxially connects the first intermediate gear and the second intermediate gear. The joint structure of a robot according to claim 1 or 2, wherein The first axis angle formed by the first gear axis and the first intermediate gear axis is selected to be 90 degrees or less, and the second axis angle formed by the second gear axis and the second intermediate gear axis is 90 degrees or more. Chosen
The first and second gears and the first and second intermediate gears are respectively composed of external bevel gears, and the first intermediate gear is farther away from the tilting axis in the intersecting direction than the second intermediate gear and is inclined. 4. The joint structure of the robot according to claim 3, wherein the joint is disposed on the same side in the direction intersecting with the second intermediate gear with respect to the axis.

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