JP2016160962A - Warping expansion mechanism and robot arm mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a warping expansion mechanism and a robot arm mechanism that can 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; 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 connection units 23 to the second connection units 24 and also supports the columnar body; and a drive gear 50 which sends the columnar body from the emission part 30 and draws the columnar body back to the emission part 30. The columnar body is in an arcuately curved columnar shape.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.

  An object of the present invention is to provide a bending and expanding / contracting mechanism and a robot arm 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 connected to bendable, a plurality of second connection pieces having a U-shaped cross-section connected to bendable, 1. A columnar body is formed by constraining bending by joining a second connecting piece, and the columnar body is released by separation of the first and second connecting pieces. A support part configured to join the second connecting piece to form the columnar body and support the columnar body; and an expansion / contraction part that sends the columnar body out of the support part and pulls the columnar body back to the support part; The columnar body has a columnar shape curved in an arc shape.

FIG. 1 is an external perspective view of the robot arm mechanism according to the first 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 perspective view of the first connecting piece of FIG. FIG. 6 is a side view of the second connecting piece of FIG. FIG. 7 is a perspective view of the second connecting piece of FIG. FIG. 8 is a perspective view of the second connecting piece of FIG. FIG. 9 is a side view of the joint portion of the first and second connecting pieces in FIG. FIG. 10 is a side view of an arm unit according to Modification 1 of the first embodiment. FIG. 11 is a side view of the first connecting piece according to the second embodiment. FIG. 12 is a perspective view of the first connecting piece of FIG. 11 as viewed from the front lower side. FIG. 13 is a perspective view of the first connecting piece of FIG. FIG. 14 is a side view of a second connecting piece according to the second embodiment. FIG. 15 is a perspective view of the second connecting piece of FIG. 14 as viewed from the front upper side. FIG. 16 is a perspective view of the second connecting piece of FIG. FIG. 17 is a side view of the joint portion of the first and second connecting pieces according to the second embodiment. FIG. 18 is a side view of the arm portion according to the second embodiment.

  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 FIGS. FIG. 1 is an external perspective view of the robot arm mechanism according to the first embodiment. FIG. 2 is a cross-sectional view showing the internal structure of the robot arm mechanism of FIG. The robot arm mechanism has a substantially cylindrical base 1, an arm 2 connected to the base 1, and a wrist 4 attached to the tip of the arm 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 corresponding to the application is attached to 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. 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 realized by the shapes of the first and second connecting pieces 23 and 24 that constitute the arm portion 2. The structure of the first and second connecting pieces 23 and 24 will be described later. 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. The bending expansion / contraction mechanism has an arm part 2 and an injection part 30. 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. Note that the surface of the first connecting piece 23 and the second connecting piece 24 facing the second rotation axis RA2 is referred to as an inner surface, and the opposite surface is referred to as an 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.

  The injection unit 30 includes a plurality of upper rollers 31 and a plurality of lower rollers 32. 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. The drive gear 50 is meshed with a linear linear gear. 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 and the motor 55 is driven and the drive gear 50 rotates in the forward direction, the first connecting top row 21 is guided between the upper roller 31 and the lower roller 32 by the guide roller 40. Along with the movement of the first connection piece row 21, the second connection piece row 22 is guided between the upper roller 31 and the lower roller 32 of the injection unit 30 by a guide rail (not shown) disposed behind the injection unit 30. . The injection unit 30 presses the first connecting piece row 21 and the second connecting piece row 22 with each other by the upper roller 31 and the lower roller 32 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 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.

  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.

(First connection piece 23)
The structure of the 1st connection top 23 which comprises the 1st connection top row | line | column 21 is demonstrated with reference to FIGS. 3-5. 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 perspective view of the first connecting piece 23 of FIG.

  The 1st connection top row | line | column 21 consists of the some 1st connection top | top | piece 23 connected in the line form. The plurality of first connecting pieces 23 have the same shape and size. The 1st connection piece 23 is comprised by the rectangular board curved in the circular arc shape from the front-end part to the rear-end part. The first connecting piece 23 has a substantially rectangular cross section and a substantially arcuate vertical cross section. The bottom sides of both edge portions of the first connection piece 23 have a shape for fitting into the side plate of the second connection piece 24. Specifically, the 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. Both edge portions of the first connecting piece 23 have a thickness t1. 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. 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. Accordingly, the bottom sides of both edge portions of the first connecting piece 23 have an arc shape with a radius (r1-t1 / 2) 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.

  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.

(Second connection piece 24)
The structure of the 2nd connection top 24 which comprises the 2nd connection top row | line | column 22 is demonstrated with reference to FIGS. 6-8. FIG. 6 is a side view of the second connecting piece 24 of FIG. FIG. 7 is a perspective view of the second connecting piece 24 of FIG. FIG. 8 is a perspective view of the second connecting piece 24 of FIG.

  The 2nd connection top row 22 consists of a plurality of 2nd connection top 24 connected in the shape of a line. The plurality of second connecting pieces 24 have the same shape and size. The second connecting piece 24 is configured as a rectangular groove-like body curved in an arc shape. The second connecting piece 24 has a U-shaped cross section. The side plate of the second connecting piece 24 has a curved shape from the front end portion to the rear end portion. The shape of the side plate of the second connecting piece 24 is defined by two concentric circles having different radii and a central angle. As shown in FIG. 6, the side plate of the second connecting piece 24 has a shape in which a ring defined by a circle with a radius r2 and a circle with a radius r3 (<r2) is divided by a central angle θ2. In other words, the side plate of the second connecting piece 24 has a shape obtained by subtracting a sector having a radius r3 (<r2) 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. 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. 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.

  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 and second connecting frame rows 21 and 22 are joined to each other by the locking mechanism, and the joined state is maintained. 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.

  FIG. 9 is a side view of a joint portion of the first and second connecting frame rows 21 and 22 in FIG. 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 an arc shape corresponding to a central angle θ1 in a circle having a radius r1 with a predetermined coordinate position on the robot coordinate system defined in the vicinity of the base 1 and near the base 1 as the center C0. 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. The upper side of the side plate of the second connecting piece 24 corresponds to an arc having a radius r2 (> r3) and a central angle θ2. The bottom side of the side plate of the second connecting piece 24 corresponds to an arc having a radius r3 (<r2) and a central angle θ2. The thickness t1 of both edge portions of the first connecting piece 23 is designed to a thickness necessary for fitting the bottom sides of both edge portions of the first connecting piece 23 to the upper side of the side plate of the second connecting piece 24. For example, as shown in FIG. 9, the thickness t1 is designed to be 2 × (r1-r2). The first and second connecting pieces 23 and 24 are configured such that the circles having radii r1, r2, and r3 (r1> r2> r3) are concentric circles centered on the center position C0. Further, the central angle θ1 that defines both edge portions of the first connecting piece 23 is preferably equivalent to the central angle θ2 that defines the shape of the side plate of the second connecting 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 can be formed into a columnar shape curved in an arc shape with the center position C0 and the radius r0.

  According to the bending expansion / contraction mechanism described above, the arm portion 2 that extends and contracts downward along the third bending axis RA3 having an arc shape with a radius r0 centered on the position C0 below the injection portion 30 is provided. Can be provided. 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 if there is an obstacle on a straight line connecting the opening of the third support 11c and the target position, the robot hand can reach the target position while avoiding the obstacle. Therefore, the robot arm mechanism according to the first embodiment can alleviate restrictions on the application environment.

  In the first embodiment, the first connecting piece 23 may be configured as a rectangular plate curved in an arc shape (constant curvature) upward and backward. For example, the first connecting piece 23 has, as its outer shape, an arc shape corresponding to the central angle θ1 in a circle having a radius r0 centered on the position C0 above the injection unit 30. At this time, the second connecting piece 24 is formed in a square groove-like body that is curved upward 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. The upper side of the side plate of the second connecting piece 24 corresponds to an arc having a radius r2 (> r1) and a central angle θ2. The bottom side of the side plate of the second connecting piece 24 corresponds to an arc having a radius r3 (> r2> r1) and a central angle θ2. As a result, it is possible to provide the arm portion 2 that is curved upward and downward along the third bending axis RA3 having an arc shape centered on the position C0 above the injection portion 30.

  The third bending axis RA3 is realized mainly by the outer shape of the first connecting piece 23 and the inner shape of the second connecting piece 24. Accordingly, the shape of the mating surfaces of the first and second connecting pieces 23 and 24 and the shape of the mating surfaces of the side plates of the second connecting piece 24 are any of a linear shape, an arc shape, a staircase shape, etc. The shape may also be

(Modification)
In the first embodiment, the plurality of second connection pieces 24 constituting the second connection piece row 22 have been described as having the same shape and the same size, but the first embodiment is not limited thereto. For example, at least one side plate of the plurality of second connection pieces 24 constituting the second connection piece row 22 may be formed in a shape defined by two concentric circles having different radii and a central angle.

  FIG. 10 is a side view of the arm unit 2 according to a modification of the first embodiment. As shown in FIG. 10, the second connection frame row 22 includes a second connection frame 24 and a plurality of fourth connection frames 26 connected in a row. The second connecting piece 24 and the fourth connecting piece 26 have a U-shaped cross section. The second connecting piece 24 is a groove-like body that is curved in an arc shape from the front end portion to the rear end portion. The side plate of the second connecting piece 24 has a shape in which a ring defined by a circle having a radius r5 and a circle having a radius r6 (<r5), which are concentric with each other, is divided by a central angle θ6. An arc having a radius r5 and a central angle θ6 corresponds to the upper side of the side plate, and an arc having a radius r6 (<r5) and the central angle θ6 corresponds to the bottom side of the side plate. 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. The fourth connecting piece 26 is configured as a rectangular groove. The side plate of the fourth connection piece 26 has a rectangular shape or a square shape.

  The first linked frame row 21 includes a first linked frame 23, a third linked frame 25, and a plurality of fifth linked frames 27. The first, third, and fifth connecting pieces 23, 25, and 27 have a thickness t1. The first connecting piece 23 is a rectangular plate that is linear from the front end to the center and curved in an arc shape from the center to the rear end. The third connecting piece 25 is a linear rectangular plate that is curved in an arc shape from the front end portion to the center portion and from the center portion to the rear end portion. The rear half of the first connecting piece 23 and the front half of the third connecting piece 25 have an arc shape with a radius r4 and a central angle θ6 / 2. When the third connecting piece 25 is connected to the rear of the first connecting piece 23, the rear half of the first connecting piece 23 and the front half of the third connecting piece 25 form a continuous arc having a radius r4 and a central angle θ6. Form. The fifth connection piece 27 is a linear rectangular plate. The thickness t1 is designed to a thickness necessary for the upper side of the side plate of the second connection piece 24 to fit over the rear half of the first connection piece 23 and the front half of the third connection piece 25.

  Due to the shape of the first and third connecting pieces 23 and 25, the rear half of the first connecting piece 23 and the front half of the third connecting piece 25 can be fitted to the side plate of the second connecting piece 24. it can. Thereby, the columnar body formed by joining the first and second connecting frame rows 21 and 22 does not expand and contract in an arc shape with a constant curvature, but a combined form in which the arc-shaped portion and the linear shape portion are combined. Can be expanded and contracted.

  According to the bending expansion / contraction mechanism described above, it is possible to provide the arm portion 2 that is partially curved downward. Thereby, the robot hand attached to the adapter of the wrist part 4 can be made to reach the target position along a track other than the straight track. Therefore, the robot arm mechanism according to the modified example of the first embodiment can ease restrictions on the application environment.

(Second Embodiment)
As long as the arm part 2 can expand and contract along a track other than the straight track, the shape of the columnar body is not limited to a curved shape. The bending expansion / contraction mechanism of the robot arm mechanism according to the second embodiment has an arm portion 2 curved in a polygonal shape. Hereinafter, the structure of the 1st connection top row | line | column 21 and the 2nd connection top row | line | column 22 which comprise the arm part 2 of the bending expansion-contraction mechanism which concerns on 2nd Embodiment is demonstrated with reference to FIGS. 12-18.

(First connection piece 23)
The structure of the 1st connection top 23 which comprises the 1st connection top row | line | column 21 is demonstrated with reference to FIGS. 11-13. FIG. 11 is a side view of the first connecting piece 23 according to the second embodiment. FIG. 12 is a perspective view of the first connecting piece 23 of FIG. 11 viewed from the front lower side. FIG. 13 is a perspective view of the first connecting piece 23 of FIG.
The 1st connection top row | line | column 21 consists of the some 1st connection top | top | piece 23 connected in the line form. The plurality of first connecting pieces 23 have the same shape and size. Both edge portions have a rectangular shape with a longitudinal section bent at a substantially central position in the longitudinal direction of the second connecting piece 24. The bending angle θ3 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. The bending angle θ3 is an angle at which the rear portion and the front portion of the first connecting piece 23 intersect, in other words, an angle at which the rear portion is inclined with respect to the front portion of the first connecting piece 23. Regarding the inner surface of the first connecting piece 23, the length W13 from the hole center to the apex of the front pinhole has the same length W14 from the apex to the hole center of the rear pinhole. The first connecting piece 23 is configured in a plate shape whose front and rear are bent inward, for example, in accordance with the longitudinal sectional shape of both edge portions thereof.

  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.

(Second connection piece 24)
The structure of the 2nd connection top 24 which comprises the 2nd connection top row | line | column 22 is demonstrated with reference to FIGS. 14-16. FIG. 14 is a side view of the second connecting piece 24 according to the second embodiment. FIG. 15 is a perspective view of the second connecting piece 24 of FIG. FIG. 16 is a perspective view of the second connecting piece 24 of FIG.

  The 2nd connection top row 22 consists of a plurality of 2nd connection top 24 connected in the shape of a line. The plurality of second connecting pieces 24 have the same shape and size. The second connecting piece 24 is configured in a short groove shape. The second connecting piece 24 has a U-shaped cross section. The side plate of the second connection piece 24 has a trapezoidal shape. In the side plate of the second connection piece 24, the length W23 of the upper side on the side joined to the first connection piece is longer than the length W24 of the bottom side of the side plate. The internal angle at the front end of the base is 90 degrees, the internal angle at the rear end of the base is (90 degrees + θ5), and the internal angle θ4 at the rear end of the top is (90 degrees−θ5). θ5 is greater than zero and is equivalent to θ3. θ5 (= θ3) is selected from the range of 1 degree or more and 10 degrees or less, preferably from the range of 2 degrees or more and 5 degrees or less. θ4 is selected from the range of 80 degrees or more and 89 degrees or less, preferably in the range of 85 degrees or more and 88 degrees or less. Note that the side plate of the second connecting piece 24 may be configured to have an isosceles trapezoidal shape. Further, the side plate of the second connecting piece 24 may be configured to have a trapezoidal shape in which the inner angle of the rear end of the upper side is 90 degrees.

  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 second embodiment, since the second 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.

  FIG. 17 is a side view of the joint portion of the first and second connecting piece rows 21 and 22 according to the second embodiment. The side plate of the second connecting piece 24 is a right-angle base with an inner angle of the front end of the base of 90 degrees, an inner angle of the rear end of the base of (90 degrees + θ5), an inner angle of the front end of the upper side of 90 degrees, and an inner angle of the rear end of the upper side of θ4 Has a shape. Therefore, when the front and rear second connection pieces 24 are connected in a row, the front second connection piece 24 is inclined downward by an angle θ5 with respect to the rear second connection piece 24.

  The first connecting piece 23 has a substantially rectangular shape in vertical section. Therefore, when the front and rear first connecting pieces 23 are connected in a row, the front end portion of the front first connecting piece 23 is inclined downward by an angle θ3 with respect to the front end portion of the rear first connecting piece 23. As shown in FIG. 17, the bending angle θ3 of the first connecting piece 23 is designed to be equivalent to the inner angle θ5 of the rear end of the bottom side of the second connecting piece 24. Further, the length W13 from the front end to the apex of the inner surface of the first connection piece 23 and the length W14 from the apex to the rear end are half the length W23 of the upper side of the side plate of the second connection piece 24. It has been designed. 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 across the side plates of the front and rear second connecting pieces 24.

  FIG. 18 is a side view of the arm unit 2 according to the second embodiment. FIG. 18A shows the arm portion 2 when the inner angle 90 ° −θ4 (= θ5, hereinafter, θ5 is referred to as a bend angle) of the second connecting piece 24 is designed to be 2 °, and FIG. The arm portion 2 when the bending angle θ5 of the second connecting piece 24 is designed to be 5 degrees is shown. The third bending axis RA3 is realized by the trapezoidal shape of the side plate of the second connecting piece 24. The radius of curvature of the third bending axis RA3 is defined by the bending angle θ5 and the length W23 of the bottom side of the side plate of the second connecting piece 24. As shown in FIGS. 18A and 18B, when the length of the second connecting piece 24 is the same, the curvature radius of the third bending axis RA3 becomes shorter as the bending angle θ5 is designed to be larger. The arm part 2 is more curved. Similarly, when the bending angle θ5 is the same, the longer the second connecting piece 24 is designed, the shorter the radius of curvature of the third bending shaft RA3 and the more the arm portion 2 is curved. The radius of curvature here refers to the radius of the circumscribed circle of the third curved axis RA3 having a polygonal shape.

  According to the bending expansion / contraction mechanism described above, it is possible to provide the arm portion 2 curved downward in a polygonal shape. Thereby, the robot hand attached to the adapter of the wrist part 4 can be made to reach the target position along a track other than the straight track. Therefore, the robot arm mechanism according to the second embodiment can ease restrictions on the application environment.

  In the above description, the plurality of second connecting pieces 24 are described as having the same shape and size, but the second embodiment is not limited thereto. Similarly to the modification of the first embodiment, also in the second embodiment, a part of the plurality of second connecting pieces 24 may have a trapezoidal side plate, and the remaining side plate may be rectangular or square. The plurality of second connecting pieces 24 may not be the same trapezoidal side plate, and the arm portion 2 may be configured by a plurality of types of second connecting pieces 24 having different trapezoidal shapes. As a result, the arm portion 2 does not expand and contract with a constant curvature, but can expand and contract in a composite form in which the polygonal portion and the linear shape portion are combined, thereby relaxing the restrictions on the application environment.

  In the second embodiment, the first connecting piece 23 may be configured in a plate shape whose front and rear are bent outward. At this time, the second connecting piece 24 is configured as a groove-like body having a trapezoidal side plate whose upper side is shorter than the bottom side. Thereby, the arm part 2 curved upward in a polygonal shape can be provided.

  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 ... Guide roller, 50 ... Drive gear, 55 ... Motor

Claims (12)

A plurality of plate-shaped first connecting pieces connected to bendable;
A plurality of second connecting pieces having a U-shaped cross-section connected so as to be bendable, and the first and second connecting pieces are joined to form a columnar body by restraining bending. The columnar body is released by the separation of the second connecting piece,
A support portion for joining the first connecting piece to the second connecting piece to form the columnar body and supporting the columnar body;
The columnar body is sent out from the support portion, and includes an extendable portion that pulls the columnar body back to the support portion,
The columnar body has a columnar shape curved in an arc shape. The first connecting piece has a rectangular plate shape curved in an arc shape,
The bending expansion / contraction mechanism according to claim 1, wherein the second connecting piece has a groove shape curved in an arc shape. A plurality of plate-shaped first connecting pieces connected to bendable;
A plurality of second connecting pieces having a U-shaped cross-section connected so as to be bendable, and the first and second connecting pieces are joined to form a columnar body by restraining bending. The columnar body is released by the separation of the second connecting piece,
A support portion for joining the first connecting piece to the second connecting piece to form the columnar body and supporting the columnar body;
The columnar body is sent out from the support portion, and includes an extendable portion that pulls the columnar body back to the support portion,
At least one of the first connecting pieces has a rectangular plate shape curved in an arc shape,
At least one of the second connecting pieces has a groove shape curved in an arc shape. A plurality of plate-shaped first connecting pieces connected to bendable;
A plurality of second connecting pieces having a U-shaped cross-section connected so as to be bendable, and the first and second connecting pieces are joined to form a columnar body by restraining bending. 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 an injection portion that supports the columnar body,
The columnar body has a columnar shape curved in a polygonal shape.   The bending expansion and contraction mechanism according to claim 4, wherein the side plate of the second connection piece has a trapezoidal shape.   The bending expansion / contraction mechanism according to claim 4, wherein a side surface of the second connection piece has a trapezoidal shape with an upper side that is joined to the first connection piece being longer than a bottom side.   The bending expansion and contraction mechanism according to claim 6, wherein at least one side plate of the second connection piece has a trapezoidal shape with an inner angle of 90 degrees on an upper side on a side to be joined to the first connection piece.   The at least one side plate of the second connecting piece has a trapezoidal shape in which an inner angle of one end of an upper side on a side to be joined to the first connecting piece is any angle of 85 to 88 degrees. The described bending expansion and contraction mechanism.   The bending expansion and contraction mechanism according to claim 4, wherein a side plate of the second connection piece has an isosceles trapezoidal shape.   The bending expansion and contraction mechanism according to claim 4, wherein all of the second connecting pieces are formed of the same trapezoidal side plate.   5. The bending expansion and contraction mechanism according to claim 4, wherein at least one of the second connection pieces is formed of a trapezoidal side plate, and the other of the second connection pieces is formed of a square or rectangular side plate.   The bending expansion and contraction mechanism according to claim 4, wherein the first connecting piece has a U-shaped longitudinal section.