JP2016160963A - Warping expansion mechanism and robot arm mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax restrictions on application environment by actualizing rounded motion.SOLUTION: A warping expansion mechanism according to an embodiment comprises: a plurality of first connection units 23 in a plate shape connected to be bendable; a plurality of connection units 24 in a channel cross-sectioned shape connected to be bendable; and an emission part 30 that has a columnar body formed as the first and second connection units 23, 24 are jointed to be restricted from being bent and also has the columnar body released as the first and second connection frames 23, 24 are separated and that constitutes the columnar body by joining the first units 23 to the second connection units 24 and also supports the columnar body. The columnar body is in an arcuately curved columnar shape. The emission part 30 includes a plurality of upper rollers 31 arranged along the columnar body so as to press the columnar body from the side of the first connection units 23, and a plurality of lower rollers 32 arrayed along the columnar body so as to press the columnar body from the side of the second connection units 24, the upper and lower rollers 31 and 32 having their positions fixed.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a bending expansion / contraction mechanism and a robot arm mechanism.

  Robot devices are applied in various fields such as production lines, medical care and nursing care, and are expected to be applied in further fields in the future. The actual production line has a wide variety of workpiece types and work contents. In addition, the work contents vary in the field of care. In addition, there are various restrictions on the surrounding environment. For example, in the conventional articulated arm mechanism, the movement of the elbow joint is very large and the movement is not predictable, so that it is limited to use in an environment where a relatively large space can be secured. In addition, the conventional articulated arm mechanism and the linear motion articulated arm mechanism are a combination of linear motions, and are applicable to environments that require curvilinear motions where obstacles are scattered. I could n’t.

International Publication No. 2011/152265

  An object is to provide a bending expansion and contraction mechanism that can alleviate restrictions on the application environment by realizing a curved movement.

  The bending expansion and contraction mechanism according to the present embodiment includes a plurality of plate-shaped first connection pieces that are connected so as to be bent, and a plurality of second connection pieces that are connected so as to be able to bend and have a U-shaped short groove in cross section. The first and second connecting pieces are joined to form a columnar body by being bent, and the first connecting piece is released by separating the first and second connecting pieces. To the second connecting piece to form the columnar body and to support the columnar body, the columnar body has a prismatic shape curved in an arc shape, the support portion, A plurality of first rollers arranged along the columnar body to hold the columnar body from the side of the first connection piece, and a line along the columnar body to hold down the columnar body from the side of the second connection piece. A plurality of second rollers arranged in a row, and the first and second rollers La is characterized in that the position is fixed.

FIG. 1 is an external perspective view of a robot arm mechanism according to the present embodiment. FIG. 2 is a cross-sectional view showing the internal structure of the robot arm mechanism of FIG. FIG. 3 is a side view of the first connecting piece of FIG. FIG. 4 is a perspective view of the first connecting piece of FIG. 1 viewed from the front lower side. FIG. 5 is a side view of the second connecting piece of FIG. FIG. 6 is a perspective view of the second connecting piece of FIG. 1 as viewed from the front upper side. FIG. 7 is a side view showing the injection unit and the drive gear of FIG. FIG. 8 is a side view showing another structure of the injection unit and the drive gear of FIG. FIG. 9 is a side view showing another structure of the injection unit and the drive gear of FIG. FIG. 10 is a side view showing another structure of the injection unit and the drive gear of FIG.

  Hereinafter, the robot arm mechanism according to the first and second embodiments will be described with reference to the drawings. The robot arm mechanism according to the first and second embodiments includes a bending expansion / contraction mechanism. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

(First embodiment)
The robot arm mechanism according to the first embodiment will be described with reference to FIG. FIG. 1 is an external perspective view of the robot arm mechanism according to the first embodiment. The robot arm mechanism has a substantially cylindrical base 1, an arm part (also referred to as a columnar body) 2 connected to the base 1, and a wrist part 4 attached to the tip of the arm part 2. The wrist part 4 is provided with an adapter (not shown). In 1st Embodiment, an adapter is provided in the rotation part of 6th rotating shaft RA6 mentioned later. A robot hand according to the application is attached through the adapter of the wrist part 4.

  The robot arm mechanism has a plurality of, here six, joint portions J1, J2, J3, J4, J5, and J6. The plurality of joint portions J1, J2, J3, J4, J5, and J6 are sequentially arranged from the base portion 1. In general, the first, second, and third joints J1, J2, and J3 are called the root three axes, and the fourth, fifth, and sixth joints J4, J5, and J6 change the posture of the robot hand 3. Called wrist 3 axis. The wrist 4 has fourth, fifth, and sixth joints J4, J5, and J6. At least one of the joint portions J1, J2, and J3 constituting the base three axes is a bending and expanding joint. Here, the third joint portion J3 is configured as a bending expansion / contraction joint portion, particularly a joint portion having a relatively long expansion / contraction distance. The arm part 2 represents the expansion / contraction part of the bending expansion / contraction joint part J3 (third joint part J3).

  The first joint portion J1 is a torsion joint centered on the first rotation axis RA1 that is supported, for example, perpendicularly to the base surface. The second joint portion J2 is a bending joint centered on the second rotation axis RA2 arranged perpendicular to the first rotation axis RA1.

  The first joint portion J1 is a torsion joint centered on the first rotation axis RA1 that is supported, for example, perpendicularly to the base surface. The second joint portion J2 is a bending joint centered on the second rotation axis RA2 arranged perpendicular to the first rotation axis RA1. A Z axis is defined parallel to the first rotation axis RA1. An orthogonal three-axis robot coordinate system (X, Y, Z) centering on the Z axis is defined.

  The third joint portion J3 is a joint in which the arm portion 2 extends and contracts along the third axis (curvature axis) RA3. The third bending axis RA3 has an arc shape with a center position C0 and a radius r0. The center position C0 of the circle is a fixed point on the moving coordinate system that moves with the rotation of the first rotation axis RA1 and the second rotation axis RA2. The radius r0 is defined by the distance from the center position C0 to the center in the thickness direction of the columnar body. That is, the arm portion 2 of the third joint portion J3 expands and contracts in an arc shape along the third bending axis RA3. The third bending axis RA3 is arranged orthogonal to the second rotation axis RA2. Since the entire arm portion 2 is curved when extended, the bending expansion / contraction joint portion J3 is also referred to as a bending expansion / contraction joint portion J3.

  The fourth joint portion J4 is a torsional joint centered on the fourth rotation axis RA4 in contact with the third bending axis RA3, and the fifth joint portion J5 is a fifth rotation axis RA5 orthogonal to the fourth rotation axis RA4. It is a bending joint centered around. The sixth joint portion J6 is a bending joint centered on the sixth rotation axis RA6 that is perpendicular to the fourth rotation axis RA4 and perpendicular to the fifth rotation axis RA5.

  The arm support body (first support body) 11a that forms the base portion 1 has a cylindrical hollow structure formed around the first rotation axis RA1 of the first joint portion J1. The first joint portion J1 is attached to a fixed base (not shown). When the first joint portion J1 rotates, the arm portion 2 pivots left and right along with the shaft rotation of the first support 11a. The first support 11a may be fixed to the ground plane. In that case, the arm part 2 is provided in a structure that turns independently of the first support 11a. A second support part 11b is connected to the upper part of the first support 11a.

  The second support portion 11b has a hollow structure that is continuous with the first support portion 11a. One end of the second support portion 11b is attached to the rotating portion of the first joint portion J1. The other end of the second support portion 11b is opened, and the third support portion 11c is fitted so as to be rotatable on the second rotation axis RA2 of the second joint portion J2. The 3rd support part 11c has a hollow structure which consists of a scale-like exterior which is connected to the 1st support part 11a and the 2nd support part. The third support portion 11c is accommodated in the second support portion 11b and sent out as the second joint portion J2 is bent and rotated. The rear part of the arm part 2 constituting the bending expansion / contraction joint part J3 (third joint part J3) of the robot arm mechanism is housed in a hollow structure in which the first support part 11a and the second support part 11b are continuous by contraction. The

  The third support portion 11c is fitted to the lower end portion of the second support portion 11b so as to be rotatable about the second rotation axis RA2 with respect to the open end lower portion of the second support portion 11b. Thereby, a second joint portion J2 as a bending joint portion around the second rotation axis RA2 is configured. When the second joint portion J2 rotates, the arm portion 2 rotates in a vertical direction around the second rotation axis RA2, that is, performs a undulation operation.

  The fourth joint portion J4 is a torsional joint having an arm central axis along the expansion / contraction direction of the arm portion 2, that is, a fourth rotation axis RA4 that typically contacts the third movement axis RA3 of the third joint portion J3. When the fourth joint portion J4 rotates, the wrist portion 4 and the robot hand attached to the wrist portion 4 rotate about the fourth rotation axis RA4. The fifth joint J5 is a bending joint having a fifth rotation axis RA5 orthogonal to the fourth rotation axis RA4 of the fourth joint J4. When the fifth joint portion J5 rotates, the fifth joint portion J5 rotates up and down (vertical direction around the fifth rotation axis RA5) together with the robot hand from the fifth joint portion J5 to the tip. The sixth joint J6 is a bending joint having a sixth rotation axis RA6 perpendicular to the fourth rotation axis RA4 of the fourth joint J4 and perpendicular to the fifth rotation axis RA5 of the fifth joint J5. When the sixth joint portion J6 rotates, the robot hand turns left and right.

  As described above, the robot hand attached to the adapter of the wrist portion 4 includes the first, second, and third joint portions J1. J2. It is moved to an arbitrary position by J3, and is arranged in an arbitrary posture by the fourth, fifth, and sixth joint portions J4, J5, and J6. In particular, the length of the extension / contraction distance of the arm part 2 of the third joint part J3 enables the robot hand to reach a wide range of objects from the proximity position of the base 1 to the remote position. Further, the curvilinear expansion / contraction operation of the arm portion 2 of the third joint portion J3 makes it possible to relax the restriction of the application environment. The third joint portion J3 is characterized by a curvilinear expansion / contraction operation realized by a bending expansion / contraction mechanism and a length of the expansion / contraction distance.

  FIG. 2 is a cross-sectional view showing the internal structure of the robot arm mechanism of FIG. As shown in FIG. 2, the arm portion 2 is composed of a first connection frame row 21 and a second connection frame row 22. The first connected frame row 21 includes a plurality of first connected frames 23. The front and rear first connecting pieces 23 are connected in a row so as to be freely bent by pins at the end portions of each other. The 1st connection top row | line | column 21 can be bent freely inside and outside.

  The second linked frame row 22 includes a plurality of second linked frames 24. The front and rear second connecting pieces 24 are connected in a row so as to be freely bent by pins at the bottom end portions of each other. The second connecting frame row 22 can be bent inward. Since the cross section of the second connecting piece 24 is U-shaped, the second connecting piece row 22 does not bend outward because the side plates of the adjacent second connecting pieces 24 collide with each other. The surface of the first connecting piece 23 (second connecting piece 24) facing the second rotation axis RA2 is referred to as the inner surface, and the opposite surface is referred to as the outer surface. A leading first linked frame 23 in the first linked frame sequence 21 and a leading second linked frame 24 in the second linked frame sequence 22 are connected by a linked frame 26. For example, the connecting piece 26 has a shape obtained by combining the first connecting piece 23 and the second connecting piece 24.

  An injection unit 30 is provided in the vicinity of the opening of the third support 11c. A guide roller 40 and a drive gear 50 are provided behind the injection unit 30 so as to face each other with the first connecting piece row 21 interposed therebetween. The drive gear 50 is connected to the motor 55 via a speed reducer (not shown). A linear gear 239 is formed on the inner surface of the first connecting piece 23 along the connecting direction. When the plurality of first connecting pieces 23 are aligned in a straight line, the linear gears 239 are connected in a straight line to form a long linear gear 239. The drive gear 50 is engaged with a linear linear gear 239. The linear gear 239 connected in a straight line forms a rack and pinion mechanism together with the drive gear 50.

  When the arm is extended, when the motor 55 is driven and the drive gear 50 rotates forward, the first connecting piece row 21 is guided to the injection unit 30 by the guide roller 40. As the first connecting piece row 21 moves, the second connecting piece row 22 is guided to the injection unit 30 by a guide rail (not shown) disposed behind the injection unit 30. The injection unit 30 presses the first connection frame row 21 and the second connection frame row 22 to form a columnar body, and supports the columnar body vertically and horizontally. When the joined state of the first and second connection frame rows 21 and 22 is maintained, the bending of the first and second connection frame rows 21 and 22 is constrained to each other. Thereby, the 1st, 2nd connection top row | line | columns 21 and 22 comprise the columnar body provided with fixed rigidity. The columnar body refers to a columnar rod body in which the first connection frame row 21 is joined to the second connection frame row 22. In this columnar body, the second connecting piece 24 and the first connecting piece 23 are formed into cylindrical bodies having various cross-sectional shapes as a whole. The cylindrical body is defined as a shape in which the top, bottom, left, and right sides are surrounded by a top plate, a bottom plate, and both side plates, and a front end portion and a rear end portion are opened. The columnar body formed by joining the first connecting piece row 21 and the second connecting piece row 22 is sent out from the opening of the third support portion 11c with the connecting piece 26 as a starting end.

  When the arm 55 is contracted and the motor 55 is driven and the drive gear 50 is rotated in the reverse direction, the first connecting piece row 21 engaged with the drive gear 50 is pulled back into the first support 11a. The columnar body is pulled back into the third support body 11c with the movement of the first connection frame row. The pulled-back columnar body is separated from the first connection frame row 21 and the second connection frame row 22 behind the injection unit 30. For example, the first connecting piece row 21 constituting the columnar body is sandwiched between the guide roller 40 and the drive gear 50, and the second connecting piece row 22 constituting the columnar body is pulled downward by gravity, whereby the second connecting piece row 22 is drawn. The frame row 22 and the first linked frame row 21 are separated from each other. The separated second connection top row 22 and first connection top row 21 return to a bendable state, are individually bent, and are stored in the first support 11a. Details of the injection unit 30 will be described later.

  The columnar body (arm portion 2) formed by joining the first and second connecting frame rows 21 and 22 has a columnar shape curved in an arc shape with a center position C0 and a radius r0. The first and second connected frame rows 21 and 22 are configured such that the columnar bodies formed by joining have the above-described shape. Hereinafter, an example of the structure of the first and second connection tops 23 and 24 constituting the first connection top row 21 and 22 will be described with reference to FIGS. In the following description, the structure of the first connecting piece 23 and the second connecting piece 24 will be described with reference to the center position C0 of the columnar body having an arc shape.

  The first connecting piece 23 is configured as a rectangular plate having a thickness t1 that is curved in a circular arc shape (constant curvature) downward in the front-rear direction. The first connecting piece 23 has a central angle θ1 for a circle having a predetermined radius r1 with a predetermined coordinate position on the robot coordinate system defined in the vicinity of the base 1 below the injection unit 30 as the center C0. It has an arc shape as its outer shape. The second connecting piece 24 is configured as a square groove-like body curved downward in a circular arc shape (constant curvature). The second connecting piece 24 has an annular shape corresponding to a central angle θ2 (= θ1) in a circle having a radius r1 with a center C0 as its outer shape.

  FIG. 3 is a side view of the first connecting piece 23 of FIG. FIG. 4 is a perspective view of the first connecting piece 23 of FIG. FIG. 5 is a side view of the second connecting piece 24 of FIG. FIG. 6 is a perspective view of the second connecting piece 24 of FIG.

(Fitting structure of the first and second connecting pieces 23 and 24)
The 1st connection top row | line | column 21 consists of the some 1st connection top | top | piece 23 which has the same shape connected in the line form. The first connecting piece 23 is a rectangular plate that is curved in an arc shape from the front end portion to the rear end portion. The first connecting piece 23 has a rectangular cross section and a substantially arc shape in vertical section. A longitudinal section of both edge portions of the first connecting piece 23 has an arc shape with a radius r1 (> r0) and a central angle θ1. In the robot arm mechanism, when the first connecting piece row 21 and the second connecting piece row 22 form a columnar body, a circle having a radius r1 that defines the shape of both edge portions of the first connecting piece 23 is the shape of the columnar body. And a concentric circle (center position C0) with a radius r0. The radius r1 is defined by the distance from the center position C0 to the center of the first connecting piece 23 in the thickness direction. Preferably, the central angle θ1 is selected from a range of 1 degree or more and 10 degrees or less, preferably a range of 2 degrees or more and 5 degrees or less, and is preferably equivalent to a center angle θ2 described later. Both edge portions of the first connecting piece 23 have a thickness t1. The thickness t <b> 1 is designed to a thickness necessary for fitting both edge portions of the first connecting piece 23 with the upper side of the side plate of the second connecting piece 24. As shown in FIG. 3, the thickness t1 is designed to be 2 × (r1-r2).

  The second connection frame row 22 includes a plurality of second connection pieces 24 having the same shape connected in a row. The second connecting piece 24 has a U-shaped cross section. The second connecting piece 24 is formed in a square groove shape curved in an arc shape. The side plate of the second connecting piece 24 has a curved shape from the front end portion to the rear end portion of the second connecting piece 24. Specifically, the side plate of the second connecting piece 24 has a shape defined by two concentric circles having different radii and a central angle. As shown in FIG. 5, the side plate of the second connecting piece 24 has a shape in which an annulus defined by a circle having a radius r2 and a circle having a radius r3 is divided by a central angle θ2. The circle with the radius r2 is a concentric circle of the circle with the radius r3. In other words, the side plate of the second connecting piece 24 has a shape obtained by subtracting a sector having a radius r3 and a central angle θ2 from a sector having a radius r2 and a central angle θ2. An arc with radius r2 and center angle θ2 corresponds to the upper side of the side plate, and an arc with radius r3 (<r2) and center angle θ2 corresponds to the bottom side of the side plate. The central angle θ2 is selected from a range of 1 degree or more and 10 degrees or less, preferably a range of 2 degrees or more and 5 degrees or less. In the robot arm mechanism, when the second connecting piece row 22 forms a columnar body together with the first connecting piece row 21, the circles having radii r2 and r3 that define the shape of the second connecting piece 24 define the shape of the columnar body. And a concentric circle (center position C0) with a radius r0. The bottom plate of the second connection piece 24 is configured as a rectangular plate curved outward from the front end portion to the rear end portion in accordance with the shape of the bottom side of the side plate of the second connection piece 24.

  Due to the shape of the first and second connecting pieces 23, 24, both edge portions of the first connecting piece 23 can be fitted over the upper sides of the side plates of the front and rear second connecting pieces 24. Thereby, the columnar body formed by joining the first and second connecting frame rows 21 and 22 forms a columnar shape curved in an arc shape with the center position C0 and the radius r0.

(Junction structure of the first and second connecting pieces 23 and 24)
A pinhole case 231 is provided at the rear center of the first connecting piece 23. Pinhole cases 232 and 233 are provided at both front ends of the first connecting piece 23, respectively. Each pinhole of the pinhole cases 231, 232, 233 is opened in parallel to the width direction of the first connecting piece 23. The pinhole cases 232 and 233 are distributed at both ends in the width direction with a distance substantially equivalent to the width of the rear pinhole case 231. The rear pinhole case 231 is inserted between the front pinhole cases 232 and 233. In this state, the pinholes in the front pinhole cases 232 and 233 and the pinholes in the rear pinhole case 231 are continuously connected. A single pin is inserted into the continuously connected pinhole. In this way, the plurality of first connecting pieces 23 are connected in a row to form the first connecting piece row 21. The front and rear first connecting pieces 23 can rotate with respect to each other about a pinhole. Thereby, the 1st connection top row | line | column 21 can be bent. The bending angle of the first connecting piece row 21 can be limited by the cross-sectional shape of the first connecting piece 23, the position of the pinhole, the shape of the pinhole cases 231, 232, 233, and the like. For example, the first connecting frame row 21 can be bent inward, but cannot be bent outward. Pinhole blocks 234 and 235 having a trapezoidal cross section are provided at the center on both sides of the inner surface of the first connecting piece 23. Lock pinholes are opened in the pinhole blocks 234 and 235.

  Pin hole cases 241, 242, and 243, chuck blocks 244 and 245, and lock pin blocks 246 and 247 are integrally formed in the second connecting piece 24. A pinhole case 241 is provided at the rear center of the second connecting piece 24. Pinhole cases 242 and 243 are provided at both front ends of the second connecting piece 24, respectively. Each pinhole case 241, 242, 243 has a pinhole parallel to the width direction of the second connecting piece 24. The pinhole cases 242 and 243 are distributed at both ends in the width direction with a distance substantially equivalent to the width of the rear pinhole case 241. The rear pinhole case 241 is inserted between the front pinhole cases 242 and 243. In this state, the pinholes in the front pinhole cases 242 and 243 and the pinholes in the rear pinhole case 241 are continuously connected. A single pin is inserted into the continuously connected pinhole. In this way, the plurality of second connecting pieces 24 are connected in a row to form a second connecting piece row 22. The front and rear second connecting pieces 24 can rotate with respect to each other about the pinhole. The bending angle of the second connecting piece row 22 can be limited by the cross-sectional shape, the position of the pinhole, the shape of the pinhole cases 241, 242, 243, and the like. In the first embodiment, since the connecting piece 24 has a substantially U-shaped cross section, the second connecting piece row 22 can be bent outward, but cannot be bent inward.

  Chuck blocks 244 and 245 are integrally formed inside the rear upper side of both side plates of the second connecting piece 24, respectively. Lock pin blocks 246 and 247 are integrally formed inside the front upper side of both side plates of the second connecting piece 24, respectively. The lock pin blocks 246 and 247 have lock pins that are respectively inserted into the pinholes of the pinhole blocks 234 and 235 described above. The lock pin has a central axis parallel to the length direction of the second connecting piece 24. The shape and axial length of the lock pin are designed according to the pinhole. When the second connecting piece row 22 is linearly aligned, the chuck blocks 244 and 245 of the front second connecting piece 24 and the lock pin blocks 246 and 247 of the rear second connecting piece 24 serve as fitting receiving portions. Form. The shapes and positions of the chuck blocks 244 and 245 and the lock pin blocks 246 and 247 are designed so that the fitting receiving portions have shapes substantially matching the pin hole blocks 234 and 235 of the first connecting piece 23. Has been.

  The pinhole blocks 234 and 235 constitute a lock mechanism together with the chuck blocks 244 and 245 and the lock pin blocks 246 and 247. The first connection frame row 21 and the second connection frame row 22 are joined to each other by the lock mechanism. Specifically, the first connection piece row 21 and the second connection piece row 22 are joined to each other by inserting the lock pins of the lock pin blocks 246 and 247 into the pinholes of the pinhole blocks 234 and 235, respectively. . The joining state of the 1st, 2nd connection top row | line | columns 21 and 22 is maintained when the pinhole blocks 234 and 235 are engage | inserted by a fitting receiving part.

(Injection part 30)
Hereinafter, the structure of the injection portion 30 of the bending expansion / contraction mechanism will be described with reference to FIG. FIG. 7 is a side view showing the injection unit 30 and the drive gear 50 of FIG. The columnar body has a columnar shape curved in an arc shape with a center position C0 and a radius r0.
The injection unit 30 includes a plurality of upper rollers 31 and a plurality of lower rollers 32. The plurality of upper rollers 31 are arranged along the columnar body (third curved axis RA3) in order to hold the curved columnar body from the first connecting piece 23 side. Similarly, the plurality of lower rollers 32 are arranged along the third bending axis RA3 in order to hold the curved columnar body from the second connecting piece 24 side. The shafts of the plurality of upper rollers 31 and the shafts of the plurality of lower rollers 32 are fixed by a curved rectangular tube-shaped frame (not shown).

  The plurality of upper rollers 31 are arranged in parallel with each other in an arc shape along a circle concentric with the arc-shaped center C0 of the columnar body (arm portion) 2. The rotation shafts of the plurality of upper rollers 31 are arranged in a circular arc shape around a circumference whose radius is a distance obtained by adding the roll radius of the upper roller 31 to the radius r7 of the outer periphery of the columnar body 2 around the center position C0. The Similarly, the plurality of lower rollers 32 are arranged in parallel with each other in an arc shape along a circle concentric with the arc-shaped center C0 of the columnar body 2. The rotation shafts of the plurality of lower rollers 32 are arranged in an arc shape along a circumference whose radius is a distance obtained by adding the roll radius of the lower roller 32 to the radius r8 of the inner periphery of the columnar body 2 around the center position C0. Is done.

  The plurality of upper rollers 31 and the plurality of lower rollers 32 are the distances between the support surfaces defined by the plurality of upper rollers 31 and the support surfaces defined by the plurality of lower rollers 32, that is, the radius r7 and the radius r8. These are arranged so that the difference between them is substantially equivalent to the thickness of the columnar body 2. Thereby, the central axis of the injection part 30 substantially coincides with the third bending axis RA3, and the curved columnar body can be supported from above and below by the plurality of upper rollers 31 and the plurality of lower rollers 32.

In addition, the rigidity of the arm part 2 can be improved by arranging a plurality of upper rollers 31 and a plurality of lower rollers 32 as described below.
That is, the plurality of upper rollers 31 and the plurality of lower rollers 32 are the distances between the support surfaces defined by the plurality of upper rollers 31 and the support surfaces defined by the plurality of lower rollers 32, that is, the radius r7 and the radius. It arrange | positions so that the difference with r8 may become slightly shorter than the thickness of a columnar body. At this time, the plurality of upper rollers 31 and the plurality of lower rollers 32 can support the columnar body in a state where a preload is applied between the columnar bodies. By applying an appropriate preload between the injection unit 30 and the columnar body, rattling at the time of arm expansion / contraction is reduced, and noise can be prevented by reducing rattling. Moreover, the holding | maintenance precision of the arm part 2 by the injection part 30 can be made high. Furthermore, the rigidity of the arm part 2 can be improved.

  The plurality of upper rollers 31 arranged on the arc having the radius r <b> 7 are arranged such that one of the adjacent upper rollers 31 is inclined with respect to the central angle θ <b> 7 from the other upper roller 31. The plurality of lower rollers 32 arranged on the arc of radius r8 are arranged such that one of the adjacent lower rollers 32 is inclined with respect to the other lower roller 32 by a central angle θ8. Preferably, the adjacent upper rollers 31 are arranged such that the central angle θ7 is substantially equivalent to or smaller than the central angle θ1 that defines the shape of the first connecting piece 23. Similarly, the adjacent lower rollers 32 are preferably arranged such that the central angle θ8 is substantially equivalent to or smaller than the central angle θ2 that defines the shape of the second connecting piece 24. Yes. By arranging in this way, it is possible to prevent the connecting portions of the first and second connecting frame rows 21 and 22 from rising inward or outward due to some factor.

  Further, as shown in FIG. 7, the plurality of upper rollers 31 and the plurality of lower rollers 32 are arranged so that the central angle θ7 and the central angle θ8 are equivalent. Accordingly, the plurality of upper rollers 31 and the plurality of lower rollers are arranged to make a pair with each other. That is, the pair of upper roller 31 and lower roller 32 are arranged to face each other with the curved columnar body interposed therebetween. The pair of upper roller 31 and lower roller 32 arranged in this way are located on the same radius of a circle (center position C0, radius r0) that defines the shape of the columnar body. As a result, the direction in which the columnar body is supported by the pair of upper roller 31 and lower roller 32 is in a straight line and orthogonal to the third bending axis RA3, so that the rigidity of the arm portion 2 can be improved.

  According to the injection part 30 of the bending expansion / contraction mechanism described above, a columnar body curved on an arc can be supported. Thereby, the robot arm mechanism according to the first embodiment can provide the arm portion 2 that expands and contracts along the third bending axis RA3. Thereby, the robot hand attached to the adapter of the wrist part 4 can be made to reach the target position in a curve. For example, even when there is an obstacle on a straight line connecting the opening of the third support 11c and the target position, the obstacle can be avoided and the target position can be reached. Therefore, the robot arm mechanism according to the first embodiment can alleviate restrictions on the application environment.

(Second Embodiment)
The injection unit 30 of the robot arm mechanism according to the second embodiment supports an arm unit 2 that is not an arc shape, for example, an arm unit 2 having a combined shape in which an arc-shaped portion and a linear shape portion are combined. Is assumed. Hereinafter, the structure of the injection unit 30 of the robot arm mechanism according to the second embodiment will be described with reference to FIG.
FIG. 8 is a side view showing another structure of the injection unit 30 and the drive gear 50 of FIG. FIG. 8A shows the injection unit 30 that supports the linear portion of the arm portion 2, and FIG. 8B shows the injection portion 30 that supports the arc-shaped portion of the arm portion 2. The first connecting piece row 21 constituting the arm unit 2 includes a plurality of first connecting pieces 23, third connecting pieces 25, and fifth connecting pieces 27. The plurality of first connecting pieces 23 are linear flat plates having the same shape and size. The third connecting piece 25 is a plate made up of a plate whose front half in the length direction is a straight plate and whose rear half is curved on an arc. The fifth connecting piece 27 is a plate in which the front half in the length direction is a curved plate and the rear half is a straight plate. A fifth connection piece 27 is connected after the third connection piece 25. Further, the second connection piece row 22 constituting the arm unit 2 includes a plurality of second connection pieces 24 and a fourth connection piece 26. The second connecting piece 24 is a short groove-like body having a square or rectangular side plate. The fourth connecting piece 26 is a short groove-like body curved from the front end portion to the rear end portion. Accordingly, the fourth connecting piece 26 has a side plate and a bottom plate that are curved from the front end portion to the rear end portion. The rear half of the third connection piece 25 and the front half of the fifth connection piece 27 can be fitted to the upper side of the side plate of the fourth connection piece 26. Thereby, the arm part 2 comprises the composite shape with which the circular-arc shaped part and the linear shape part were combined.

  The injection unit 30 includes a plurality of upper rollers 31 and a plurality of lower rollers 32. The plurality of upper rollers 31 are arranged along the columnar body in order to hold the partially curved columnar body 2 from the first connecting piece 23 side. Similarly, the plurality of lower rollers 32 are arranged along the columnar body 2 in order to press the partially curved columnar body from the second connecting piece 24 side. The plurality of upper rollers 31 and the plurality of lower rollers 32 are rotatably supported by an upper frame 35 and a lower frame 36, respectively. The upper frame 35 and the lower frame 36 are fixed to the third support 11c, for example.

  The plurality of upper rollers 31 are arranged at equal intervals in the direction (the + X-axis direction in the figure) in which the columnar body 2 is sent out. Similarly, the plurality of lower rollers 32 are arranged at equal intervals in the direction in which the columnar body 2 is sent out. The distance W31 between the rotation axes of the adjacent upper rollers 31 is designed to be equivalent to the length of the first connecting piece 23 or shorter than the length of the first connecting piece 23. Similarly, the distance W32 between the rotation axes of the adjacent lower rollers 32 is designed to be equivalent to the length of the second connecting piece 24 or shorter than the length of the second connecting piece 24. By arranging in this way, it is possible to prevent the connecting portions of the first and second connecting frame rows 21 and 22 from rising outward.

  As shown in FIG. 8, the distance W31 between the rotation axes of the adjacent upper rollers 31 is designed to be equivalent to the distance W32 between the rotation axes of the adjacent lower rollers 32. At this time, the plurality of upper rollers 31 and the plurality of lower rollers 32 are arranged to make a pair with each other. The pair of upper roller 31 and lower roller 32 arranged in this manner face each other across the linear portion of the columnar body. Thus, when the linear portion of the columnar body is supported by the injection unit 30, the direction in which the columnar body is supported by the pair of upper roller 31 and lower roller 32 is aligned. Therefore, the rigidity of the arm part 2 can be improved.

  The rearmost upper roller 31 among the plurality of upper rollers 31 and the foremost lower roller 32 among the plurality of lower rollers 32 are fixed to the upper frame 35 and the lower frame 36, respectively. As shown in FIG. 8A, the rearmost upper roller 31 and the foremost lower roller 32 are the last in the thickness direction of the columnar body when the injection portion 30 supports the linear portion of the columnar body. The distance between the support surface on which the tail upper roller 31 supports the columnar body 2 and the support surface on which the foremost lower roller 32 supports the columnar body 2 is substantially equivalent to the thickness of the columnar body or shorter than the thickness of the columnar body. It is arranged as follows. When the distance between the support surface where the rearmost upper roller 31 supports the columnar body 2 and the frontmost lower roller 32 supports the columnar body 2 is slightly shorter than the thickness of the columnar body, the rearmost upper roller 31 and the foremost lower roller 32 can support the columnar body 2 in a state in which a preload is applied between the linearly shaped portion of the columnar body. Thereby, the rigidity of the arm part 2 can be improved.

  The other upper rollers 31 among the plurality of upper rollers 31 are supported so as to be movable in a direction approaching and separating from the columnar body with respect to the upper frame 35. Similarly, the other lower rollers 32 among the plurality of lower rollers 32 are supported so as to be movable in a direction approaching and separating from the columnar body 2 with respect to the lower frame 36. Specifically, the other upper roller 31 and the other lower roller 32 are supported by the upper frame 35 and the lower frame 36 via coil springs 39, respectively. The other upper roller 31 and the other lower roller 32 are urged toward the columnar body 2 by the coil spring 39. The biasing force by the coil spring 39 always presses the other upper roller 31 and the other lower roller 32 against the surface of the columnar body. Even when the thickness of the columnar body is partially different or the shape of the columnar body is partially different due to the urging force of the coil spring 39, it is between the other upper roller 31 and the columnar body and between the other lower roller 32 and the columnar body. Preload can be applied to the body at all times. Thereby, the injection | emission part 30 can support a columnar body in the state in which the preload was applied between columnar bodies. Thereby, the rigidity of the arm part 2 can be improved.

  According to the injection part 30 of the bending expansion / contraction mechanism described above, the arm part 2 having a composite shape in which the arc-shaped part and the linear part are combined can be supported. Thereby, the robot hand attached to the adapter of the wrist part 4 can be made to reach the target position in a trajectory other than a straight line and a curved line. Therefore, the robot arm mechanism according to the second embodiment can ease restrictions on the application environment.

(Modification 1)
The ejection unit 30 of the robot arm mechanism according to the first modification of the second embodiment is assumed to support an arm unit 2 that is not in an arc shape, for example, an arm unit 2 having a polygonal shape. Hereinafter, the structure of the injection unit 30 of the robot arm mechanism according to Modification 1 of the second embodiment will be described with reference to FIG.
FIG. 9 is a side view showing another structure of the injection unit 30 and the drive gear 50 of FIG. The second connecting piece 24 has a short groove shape with a U-shaped cross section and a trapezoidal side surface. The side plate of the second connecting piece 24 has an inner angle at the front end of the base of 90 degrees, the inner angle of the rear end of the base is (90 degrees + θ5), the inner angle of the front edge of the upper side is 90 degrees, (90 degrees -θ5). The first connecting piece 23 has a shape that fits into the shape of the upper side of the side plate of the second connecting piece 24. For example, the first connecting piece 23 has a plate shape with a vertical cross section. The bending angle of the first connecting piece 23 is equivalent to θ5. Thereby, the columnar body (arm part 2) by joining the 1st, 2nd connection top row | line | columns 21 and 22 has a polygonal shape whose interior angle is 180 degree | times-(theta) 5. In other words, the bending expansion / contraction joint part J3 has a polygonal third bending axis RA3 having an inner angle of 180 degrees −θ5. The center position of the circumscribed circle of the third bending axis RA3 is C0.

  The injection unit 30 includes a plurality of upper rollers 31 and a plurality of lower rollers 32. The plurality of upper rollers 31 are arranged along the columnar body in order to press the columnar body curved in a polygonal shape from the first connecting piece 23 side. Similarly, the plurality of lower rollers 32 are arranged along the columnar body in order to press the columnar body curved in a polygonal shape from the second connecting piece 24 side. The plurality of upper rollers 31 and the plurality of lower rollers 32 are rotatably supported by an upper frame 35 and a lower frame 36, respectively. The upper frame 35 and the lower frame 36 are fixed to the third support 11c, for example.

  The plurality of upper rollers 31 and the plurality of lower rollers 32 are arranged in accordance with the shape of the columnar body 2. The rearmost upper roller 31 among the plurality of upper rollers 31 is fixed to the upper frame 35. The foremost lower roller 32 of the plurality of lower rollers 32 is fixed to the lower frame 36. The difference between the distance from the center position C0 to the support surface on which the rearmost upper roller 31 supports the columnar body and the distance from the center position C0 to the support surface on which the foremost lower roller 32 supports the columnar body is the difference between the columnar body The distance is equal to or greater than the length corresponding to the thinnest portion and equal to or less than the length corresponding to the thickest portion of the columnar body.

  Of the plurality of upper rollers 31, the other upper rollers 31 other than the last are supported so as to be movable in the direction of approaching and separating from the columnar body with respect to the upper frame 35. Similarly, the lower rollers 32 other than the foremost among the plurality of lower rollers 32 are supported so as to be movable in a direction approaching and separating from the columnar body with respect to the lower frame 36. Specifically, the other upper roller 31 and the other lower roller 32 are fixed to the upper frame 35 and the lower frame 36 via coil springs 39, respectively. The other upper roller 31 and the other lower roller 32 are urged toward the columnar body by the coil spring 39. The other upper roller 31 and the other lower roller 32 are urged in a linear direction with the center position C0 as the center. The biasing force by the coil spring 39 always presses the other upper roller 31 and the other lower roller 32 against the surface of the columnar body. Even when the thickness of the columnar body is partially different or the shape of the columnar body is partially different due to the urging force of the coil spring 39, it is between the other upper roller 31 and the columnar body and between the other lower roller 32 and the columnar body. Preload can be applied to the body at all times. Thereby, the injection | emission part 30 can support a columnar body in the state in which the preload was applied between columnar bodies. Thereby, the rigidity of the arm part 2 can be improved.

  The pair of upper roller 31 and lower roller 32 are arranged on the same straight line passing through the center position C0. The pair of upper rollers 31 and the lower rollers 32 are disposed at positions inclined by a central angle θ9 from the pair of adjacent upper and lower rollers 31 and 32. Preferably, the central angle θ9 is equivalent to or smaller than the angle θ5. By arranging in this way, it is possible to prevent the connected portions of the first and second connected frame rows 21 and 22 from rising upward due to some factor. According to the injection part 30 of the bending expansion / contraction mechanism described above, the columnar body curved in a polygonal shape can be supported.

(Modification 2)
In the injection unit 30, the second connecting piece 24 is joined to the aligned first connecting piece 23 while being aligned to form a columnar body. Specifically, among the front and rear second connection pieces 24, the chuck blocks 244 and 245 of the front second connection piece 24 and the lock pin blocks 246 and 247 of the rear second connection piece 24 are the first connection pieces. 23 pinhole blocks 234 and 235 are sandwiched. At this time, the lock pins of the lock pin blocks 246 and 247 are inserted into the pinholes of the pinhole blocks 234 and 235. Thereby, the 1st, 2nd connection top row | line | columns 21 and 22 are mutually joined, and comprise a columnar body.

  As shown in FIG. 9, when the second connecting piece 24 has a trapezoidal side plate, when the first and second connecting piece rows 21 and 22 are joined to each other at the injection unit 30, the side plate of the second connecting piece 24. May collide with the inner surface of the first connecting piece 24. In such a case, the first and second connecting piece rows 21 and 22 may be joined to each other by a lock mechanism as shown in FIG. FIG. 10 is a side view showing another structure of the injection unit and the drive gear of FIG. The lock mechanism shown in FIG. 10 is configured such that the lock pins 61 and 62 provided on the first connection piece 23 are inserted into the pin holes 63 and 64 provided on the second connection piece 24, thereby The frame rows 21 and 22 are joined to each other. Specifically, the lock pins 61 and 62 have a cylindrical shape. The lock pins 61 and 62 are fixed obliquely toward the front on both edge portions that are fitted to the side plates of the second connection piece 24 at the rear of the inner surface of the first connection piece 23. The pinholes 63 and 64 have shapes that substantially match the lock pins 61 and 62. The pinholes 63 and 64 are provided obliquely toward the front end in front of the side plate of the second connecting piece 24.

  As shown in FIG. 10, a guide roller 42 is disposed behind the injection unit 30 in order to align the second connection piece 24 before the first connection piece 23 is aligned. The drive gear 50 and the guide roller 40 are arranged such that the first connection piece 23 covers the second connection piece 24 after alignment from above. When the first connecting piece 23 and the second connecting piece 24 are guided to the injection unit 30, the first and second connecting pieces 23 and 24 are pressed against each other by the rearmost upper roller 31 and the rearmost lower roller 32. Is done. At this time, the first connecting piece 23 is covered with the second connecting piece 24 from above, and the lock pins 61 and 62 of the first connecting piece 23 are inserted into the pin holes 63 and 64 of the second connecting piece 24. It is. Accordingly, the first and second connection piece rows 21 and 22 can be joined to each other by the injection unit 30 without the front end portion of the side plate of the second connection piece 24 colliding with the inner surface of the first connection piece 24.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Base part, 2 ... Arm part, 4 ... Wrist part, J1, J2, J4, J5, J6 ... Rotary joint part, J3 ... Bending (curvature) expansion-contraction joint part, 11a ... 1st support body, 11b ... 2nd Support body 11c 3rd support body 21 First connection frame row 22 Second connection frame row 23 First connection frame 24 Second connection frame 26 Connection frame 30 Injection unit 40, 42 ... guide roller, 50 ... drive gear, 55 ... motor

Claims (10)

A plurality of plate-shaped first connecting pieces connected to bendable;
A plurality of second connection pieces having a U-shaped short cross-sectional shape that are connected so as to be bendable, and the first and second connection pieces are joined together to form a columnar body by restraining bending. 1. The columnar body is released by the separation of the second connecting piece.
The first connecting piece is joined to the second connecting piece to form the columnar body and support the columnar body,
The columnar body has a columnar shape curved in an arc shape,
The support portion is configured to hold a plurality of first rollers arranged along the columnar body in order to press the columnar body from the first connecting piece side, and to hold the columnar body from the second connecting piece side. A plurality of second rollers arranged along the columnar body,
A bending expansion / contraction mechanism characterized in that the positions of the first and second rollers are fixed.   2. The bending expansion / contraction mechanism according to claim 1, wherein each of the first rollers is positioned on the same arc radius of the pair of the second roller and the columnar body. A plurality of first connecting pieces connected to bendable;
Separation of the first and second connecting pieces, wherein a plurality of second connecting pieces connected to bendable and the first and second connecting pieces are joined to form a columnar body by restraining the bending. The columnar body is released by
The first connecting piece is joined to the second connecting piece to form the columnar body and support the columnar body,
At least two of the first connecting pieces have a plate shape curved in an arc shape, and the other first connecting pieces have a flat plate shape,
At least one of the second connecting pieces has a short groove shape with a U-shaped cross section curved in an arc shape, and the other second connecting piece has a shape of a straight cross section with a U-shaped short groove shape. ,
The support portion is configured to hold a plurality of first rollers arranged along the columnar body in order to press the columnar body from the first connecting piece side, and to hold the columnar body from the second connecting piece side. A plurality of second rollers arranged along the columnar body,
The last first roller of the plurality of first rollers is fixed,
A bending expansion / contraction mechanism, wherein a foremost second roller of the plurality of second rollers is fixed. The first rollers other than the last first roller among the plurality of first rollers are supported so as to be movable toward and away from the columnar body, and are urged in a direction approaching the columnar body,
Of the plurality of second rollers, the second rollers other than the foremost second roller are supported so as to be movable toward and away from the columnar body, and are urged in a direction approaching the columnar body. The bending and extending / contracting mechanism according to claim 3.   4. The bending expansion and contraction mechanism according to claim 3, wherein each of the first rollers is located on the same arc radius of the pair of the second roller and the columnar body.   5. The bending expansion / contraction mechanism according to claim 4, wherein the other first roller and the other second roller are supported so as to be movable on the same arc radius of the columnar body. A plurality of plate-shaped first connecting pieces connected to bendable;
Separation of the first and second connecting pieces, wherein a plurality of second connecting pieces connected to bendable and the first and second connecting pieces are joined to form a columnar body by restraining the bending. The columnar body is released by
The first connecting piece is joined to the second connecting piece to form the columnar body and support the columnar body,
The first connecting piece has a vertical cross-sectional shape,
The second connecting piece has a U-shaped cross section, a side-trapezoidal short groove shape,
The support portion is configured to hold a plurality of first rollers arranged along the columnar body in order to press the columnar body from the first connecting piece side, and to hold the columnar body from the second connecting piece side. A plurality of second rollers arranged along the columnar body,
The last first roller of the plurality of first rollers is fixed,
A bending expansion / contraction mechanism, wherein a foremost second roller of the plurality of second rollers is fixed. The first rollers other than the last first roller among the plurality of first rollers are supported so as to be movable toward and away from the columnar body, and are urged in a direction approaching the columnar body,
Of the plurality of second rollers, the second rollers other than the foremost second roller are supported so as to be movable toward and away from the columnar body, and are urged in a direction approaching the columnar body. The bending and extending / contracting mechanism according to claim 7.   8. The bending expansion / contraction mechanism according to claim 7, wherein each of the first rollers is located on the same arc radius of the pair of second rollers and the columnar body. 9. The bending expansion / contraction mechanism according to claim 8, wherein the other first roller and the other second roller are supported so as to be movable on the same arc radius of the columnar body.