JP2016209970A - Robot arm mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize bending restriction and release thereof of plural connection pieces which are connected to each other in a row form and solely constitute a columnar body with a simple mechanism.SOLUTION: A direct-acting telescopic joint part J3 of a robot arm mechanism have first and second connection pieces 21, 23 which have shapes different from each other and are alternately connected in a row form. A columnar body is configured by bending restriction of the first and second connection pieces 21, 23. Each of the first and second connection pieces 21, 23 is provided with hooks on front and rear portions respectively on a surface side thereof. Bending of the first connection piece 21 is restricted by engagement between the hooks of the front and rear first connection pieces 21, and the first connection piece is returned to a bent state by release of the engagement. Bending of the second connection piece 23 is restricted by engagement between the hooks of the front and rear second connection pieces 23 with the first connection piece 21 interposed therebetween, and the second connection piece is returned to a bent state by release of the engagement. The bending restriction state/bent state of the first and second connection pieces 21, 23 are converted by change of directions of the first and second connection pieces 21, 23.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a robot arm mechanism.

  The vertical articulated arm mechanism is required to have three degrees of freedom (x, y, z) with respect to position and three degrees of freedom (φ, θ, ψ) with respect to posture. The translational movement of the hand requires joint rotation of the joints J1, J2, and J3, and therefore the movement of the joint J2, particularly called the elbow, is very large and cannot be predicted. Especially in the vicinity of the singular point, the elbow It is inevitable that the movement of the robot becomes very fast. One effective measure for securing 6 degrees of freedom after eliminating the elbow joint is to employ a linear motion extension mechanism. The linear motion expansion / contraction mechanism is characterized in that the movable range of the linear motion arm is larger than that of the conventional linear motion mechanism. The linear motion arm is composed of, for example, a plurality of connecting pieces connected in a row. Ensuring the rigidity of the linear motion arm is an important issue for the practical application of the linear motion expansion / contraction mechanism.

  The purpose is to realize a plurality of connecting pieces connected in a row to form a columnar body, and to bend and release the connecting pieces with a simple mechanism.

  The robot arm mechanism according to the present embodiment includes a rotary joint portion and a linear motion expansion / contraction joint portion, and the linear motion expansion / contraction joint portion includes a plurality of connection pieces that are flexibly connected on the back side, and the connection piece. A support part that supports the columnar body, the storage part that stores the bent connection piece in a direction different from the support part, and the support part and the storage part. A connecting section that conveys the connecting piece between the first and second connecting pieces having different shapes, the first and second connecting pieces being alternately arranged, The first connecting piece is provided with first hooks on the front and rear sides of the surface side, and the front and rear first connecting pieces are bent and restrained by the front and rear first hooks engaging with each other with the second connecting piece interposed therebetween. To disengage the front and rear first hooks. The second connecting piece is provided with second hooks on the front and rear sides of the front side, and the front and rear second connecting pieces sandwich the first connecting piece therebetween and the front and rear second hooks. The first and second connecting pieces are restrained to bend by engaging each other, returned to the bent state by disengaging the front and rear second hooks, and changed in direction between the support part and the storage part. The bending restraint state / bending state of is switched.

FIG. 1 is an external perspective view of a robot arm mechanism according to the present embodiment. FIG. 2 is a side view showing the internal structure of the robot arm mechanism of FIG. FIG. 3 is a perspective view showing the arm portion of FIG. FIG. 4 is a diagram illustrating the first connection piece of FIG. FIG. 5 is a diagram illustrating the second connection piece of FIG. 3. FIG. 6 is a view showing a bending restraining / releasing mechanism of the first connecting piece of FIG. FIG. 7 is a side view showing a bending restrained state of the first connecting piece of FIG. FIG. 8 is a view showing a bending restraining / releasing mechanism of the second connecting piece of FIG. FIG. 9 is a side view showing a bending restrained state of the second connecting piece of FIG. FIG. 10 is a side view showing the storage portion of the robot arm mechanism according to the first modification of the present embodiment. FIG. 11 is a perspective view showing an arm portion of a robot arm mechanism according to Modification 2 of the present embodiment. FIG. 12 is a diagram illustrating the first connection piece of FIG. 11. FIG. 13 is a diagram showing the second linked piece of FIG.

  Hereinafter, the robot arm mechanism according to the present embodiment will be described with reference to the drawings. The robot arm mechanism according to the present embodiment has a rotary joint part and a linear motion expansion / contraction joint part. 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.

  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 hand device. 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 linear motion expansion / contraction joint. Here, the third joint portion J3 is configured as a linear motion expansion / contraction joint, particularly a joint portion having a relatively long expansion / contraction distance. The arm part 2 is a main component constituting the 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 third joint portion J3 is a joint in which the arm portion 2 expands and contracts linearly around a third axis (moving axis) RA3 arranged perpendicular to the second rotation axis RA2.

  The fourth joint portion J4 is a torsion joint centered on the fourth rotation axis RA4 that coincides with the third movement 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 J <b> 1 rotates, the first support 11 a rotates along with the turning of the arm portion 2. 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. The second support 11b is connected to the upper part of the first support 11a.

  The second support 11b has a hollow structure that is continuous with the first support 11a. One end of the second support 11b is attached to the rotating part of the first joint J1. The other end of the second support 11b is opened, and the third support 11c is fitted so as to be rotatable on the second rotation axis RA2 of the second joint portion J2. The 3rd support body 11c has a hollow structure which consists of a scale-like exterior which is connected to the 1st support body 11a and the 2nd support body. The third support 11c is housed in the second support 11b and is sent out as the second joint J2 is bent and rotated. The rear part of the arm part 2 that constitutes the linear motion expansion / contraction joint part J3 (third joint part J3) is housed inside the first support 11a due to its contraction. The first support 11 a is also referred to as a storage portion 11 a that stores the arm portion 2.

  The third support 11c is fitted at the lower end of the rear end thereof to the lower open end of the second support 11b so as to be rotatable about the second rotation axis RA2. 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 of the second joint portion J2, together with the wrist portion 4 and the hand device, that is, performs a hoisting operation.

  The fourth joint portion J4 is a torsional joint having a fourth rotation axis RA4 that typically coincides with the arm central axis along the expansion / contraction direction of the arm portion 2, that is, the third movement axis RA3 of the third joint portion J3. . When the fourth joint portion J4 rotates, the fourth joint portion J4 rotates from the fourth joint portion J4 to the tip together with the hand device 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, it rotates up and down together with the hand device 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 hand device turns left and right.

  As described above, the hand device 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 linear motion expansion / contraction distance of the third joint portion J3 enables the hand device to reach a wide range of objects from the proximity position of the base 1 to the remote position. The third joint portion J3 is characterized by the length of the linear motion expansion / contraction distance realized by the linear motion expansion / contraction mechanism constituting the third joint portion J3.

  FIG. 2 is a perspective view showing the internal structure of the robot arm mechanism of FIG. The linear motion expansion / contraction mechanism constituting the third joint portion (linear motion expansion / contraction joint portion) J3 includes an arm portion 2, an injection portion 30, a guide roller 40, and a drive gear 50. The drive gear 50 constitutes a transport unit together with the guide roller 40.

  The arm portion 2 is formed by connecting a plurality of connecting pieces. The plurality of connected pieces include a first connected piece 21 and a second connected piece 23 due to the difference in shape. The first and second connecting pieces 21 and 23 are short cylindrical bodies having a square cross section. The first connection pieces 21 and the second connection pieces 23 are alternately arranged, and are connected in a row by pins before and after the bottom of each other. The arm portion 2 can be bent to the bottom side (inner side) connected by the connecting pin depending on the cross-sectional shape of the first and second connecting pieces 21 and 23 constituting the arm portion 2, but the side opposite to the connecting pin ( The outer side is not bendable due to the contact between the side plate end surfaces of the adjacent first and second connecting pieces 21 and 23. The arrangement of the first and second connecting pieces 21 and 23 constitutes a columnar body having a certain rigidity by restraining inward bending by a bending restraining structure described later. The columnar body is released when the bending of the first and second connecting pieces 21 and 23 is restored. The surfaces of the first and second connecting pieces 21 and 23 facing the second rotation axis RA2 are the back surfaces of the first and second connecting pieces 21 and 23, and the opposite surfaces of the first and second connecting pieces 21 and 23 are the first and second connecting pieces. It is called the surface of 21 and 23. Of the four plates constituting the first and second connecting pieces 21 and 23, two plates provided perpendicularly to the bottom plate are referred to as side plates, and the plate provided to face the bottom plate is referred to as a top plate. A cylindrical portion is defined by the back surface of each plate. Linear gears (not shown) are formed on the surfaces of the bottom plates of the first and second connecting pieces 21 and 23 along the connecting direction (length direction). When the plurality of first and second connecting pieces 21 and 23 are aligned in a straight line, the linear gears are connected in a straight line to form a long linear gear.

  The injection unit 30 includes a plurality of upper rollers 31 and a plurality of lower rollers 32 supported by a rectangular tube-shaped frame 35. For example, the plurality of upper rollers 31 are arranged along the arm central axis at a predetermined interval, and support the arm portion 2 from the upper surface. Similarly, the plurality of lower rollers 32 are arranged along the arm central axis at a predetermined interval, preferably at an interval substantially equivalent to the arrangement interval of the upper rollers 31, and support the arm portion 2 from the lower surface. A part of the injection plate 30 behind the bottom plate is cut out, and a drive gear 50 is provided in the cut out part. The position where the drive gear 50 is provided corresponds to the position of the linear gear provided on the bottom plate surface of the first and second connecting pieces 21, 23. The drive gear 50 is connected to the motor 55 via a speed reducer (not shown). The drive gear 50 is meshed with a linear linear gear. The linear gear connected in a straight line forms a rack and pinion mechanism together with the drive gear 50.

  A plurality of guide rollers 40 are provided from the rear of the injection unit 30 to the first support (housing unit) 11a. The plurality of guide rollers 40 have rotation axes parallel to the width direction of the first and second connecting pieces 21 and 23. The plurality of guide rollers 40 form a movement path of the plurality of first and second connecting pieces 21 and 23 (arm unit 2) between the first support (housing unit) 11a and the injection unit 30. Among the plurality of guide rollers 40, the leading guide roller 40 is provided at the same position as the plurality of lower rollers 32 in the height direction of the arm portion 2. The other guide rollers 40 are arranged between the leading guide roller 40 and the first support 11a.

  The first and second connecting pieces 21, 23 are accommodated in the first support 11a in a vertical posture. When the motor 55 is driven and the drive gear 50 rotates forward, the plurality of first and second connecting pieces 21 and 23 are held in the vertical posture from the first support 11a by the other guide rollers 40. It is guided to the leading guide roller 40 while bending inward. The first and second connecting pieces 21 and 23 guided to the leading guide roller 40 are turned from the vertical posture to the horizontal posture by the leading guide roller 40. The first and second connecting pieces 21 and 23 whose directions are changed to the horizontal posture are guided to the injection unit 30. The plurality of first and second connecting pieces 21 and 23 are constrained to bend when the direction is changed from the vertical posture to the horizontal posture to form a columnar body. The injection unit 30 supports the columnar body vertically and horizontally. The columnar body is held in a restrained state by the injection unit 30 being held vertically and horizontally. Thereby, the columnar body has a certain rigidity, and is sent out from the opening of the third support 11c linearly along the third movement axis RA3.

  When the motor 55 is driven and the drive gear 50 rotates in the reverse direction, the columnar body is pulled back inward from the opening of the third support 11c, and is guided from the horizontal posture to the vertical posture by the leading guide roller 40 at the rear of the injection unit 30. Redirected to When the columnar body changes its direction from the vertical posture to the horizontal posture, the bending restrained state is released and the columnar body is separated into the first and second connecting pieces 21 and 23. The separated first and second connecting pieces 21, 23 return to a state in which they can be bent individually, and are housed in the first support (housing portion) 11a in a vertical posture.

FIG. 3 is a perspective view showing the arm portion 2 of FIG. FIG. 4 is a diagram showing the first connection piece 21 of FIG. FIG. 5 is a diagram showing the second connection piece 23 of FIG.
As shown in FIG. 3, in the arm part 2, the 1st connection piece 21 and the 2nd connection piece 23 are arranged alternately, and are connected in a row by the pin before and behind each other bottom part. The first and second connecting pieces 21 and 23 have the same width and the same height. A frame main body portion 230 (hereinafter referred to as a second main body portion 230) of the second connection piece 23 is configured in the same shape as a frame main body portion 210 (hereinafter referred to as a first main body portion 210) of the first connection piece 21. The The second body portion 230 has the same length L21 as the length L11 of the first body portion 210. However, the present invention is not limited to this, and the second main body portion 230 may be configured to have a different length from the first main body portion 210.

  As shown in FIG. 4, the first connecting piece 21 is provided with a first main body portion 210, a pair of hooks 211 that protrudes in front of the first main body portion 210, and a rear of the first main body portion 210. And a pair of hooks 213. The first body portion 210 typically has a cylindrical body with a rectangular cross section. The 1st main-body part 210 is not limited to cross-sectional square shape, You may be comprised by the trapezoidal shape and the 5 or more polygonal cylindrical body.

  The pair of hooks 211 and the pair of hooks 213 are formed on the upper portion of the first main body portion 210. The pair of hooks 211 are provided separately in the width direction of the first main body portion 210. Similarly, the pair of hooks 213 are provided separately in the width direction of the first main body portion 210. Each of the hooks 211 and 213 has a width that is 1/3 of the width of the first main body portion 210. The tip portion of the hook 211 is bent into a bowl shape. At least the inner surface of this bowl-shaped portion is formed in an arc shape centering on the connecting pin. A receiving hole for receiving a flange at the tip of the hook 211 is formed at the tip of the hook 213. The protruding length L12 of the pair of hooks 211 protruding forward of the first main body portion 210 has a length exceeding 1/2 of the length L21 of the second main body portion 230. Similarly, the protruding length L13 of the pair of hooks 213 protruding rearward of the first main body portion 210 is longer than half the length L21 of the second main body portion 230, preferably the same as the protruding length L12. Have a length of The total length of the hooks 211 and 213 before and after the first connecting piece 21 is longer than the length of the second main body portion 230 of the second connecting piece 23, and similarly the total length of the hooks 231 and 233 before and after the second connecting piece 23. Is longer than the length of the first body portion 210. As a result, of the first connecting piece 21 that moves back and forth across the second connecting piece 23, the hooked portion of the tip of the hook 211 of the rear first connecting piece 21 and the hook 213 of the front first connecting piece 21 are received. The hole portion overlaps at the upper center of the main body portion 230 of the second connecting piece 23.

  As shown in FIG. 5, the second connecting piece 23 includes a second main body portion 230, a hook 231 that protrudes in front of the second main body portion 230, and a hook 233 that protrudes in the rear of the second main body portion 230. It consists of. The second main body portion 230 has the same cross-sectional shape as the first main body portion 210, typically a cylindrical body having a cross-sectionally rectangular shape. The hook 231 and the hook 233 are formed on the second body portion 230. The hook 231 is provided at the center in the width direction of the second main body portion 230. Similarly, the hook 233 is provided in the center of the second body portion 230 in the width direction. Each of the hooks 231 and 233 has a width that is 1/3 of the width of the second main body portion 230. The total width of the pair of hooks 211 and hooks 231 matches the width of the first and second main body portions 210 and 230. Similarly, the total width of the pair of hooks 213 and hooks 233 matches the width of the first and second body portions 210 and 230.

  The tip portion of the hook 231 is bent into a bowl shape. At least the inner surface of this bowl-shaped portion is formed in an arc shape centering on the connecting pin. A receiving hole for receiving the hook portion of the hook 231 is formed at the tip portion of the hook 233. The protruding length L22 of the pair of hooks 231 protruding forward with respect to the second main body portion 230 has a length that is more than ½ of the length L11 of the first main body portion 210. Similarly, the protrusion length L23 of the pair of hooks 233 protruding backward with respect to the second body portion 230 is more than ½ of the length L11 of the first body portion 210, preferably the protrusion length L22. Have the same length. Of the second connecting pieces 23 that are moved back and forth across the first connecting piece 21, a hook-shaped portion at the tip of the hook 231 of the second connecting piece 23 at the rear and a receiving hole portion of the hook 233 of the second connecting piece 23 at the front. Is overlapped at the upper center of the main body portion 210 of the first connecting piece 21.

  As shown in FIG. 3, the pair of hooks 211, 213 and hooks 231, 233 are formed such that the upper surface of the columnar body forms a plane. For example, as shown in FIG. 4, the pair of hooks 211 and 213 are provided on the upper left and right of the first main body portion 210. As shown in FIG. 5, the hooks 231 and 233 are provided at the center of the upper width of the second main body portion 230. Note that hooks 211 and 213 having a width that is ½ of the width of the first main body portion 210 are provided on the upper right side of the first main body portion 210, and hooks having a width that is ½ of the width of the second main body portion 230. 231 and 233 may be provided on the upper left side of the second body portion 230.

  Next, a mechanism for restraining the bending of the first connecting piece 21 will be described with reference to FIGS. FIG. 6 is a view showing a bending restraining / releasing mechanism of the first connecting piece 21 of FIG. Here, in order to explain the bending restraining mechanism of the first connecting piece 21, the second connecting piece 23 is schematically shown. As the arm portion 2 is sent out by forward rotation of the drive gear 50, the first connecting piece 21 moves from the vertical posture shown in FIG. 6 (a) to the posture shown in FIG. Turned to the horizontal posture shown. The bending of the front and rear first connecting pieces 21 is restricted by engaging each other with the second connecting piece 23 therebetween. Specifically, as shown in FIG. 6, when the arm is extended, the rear first connecting piece 21 among the front and rear first connecting pieces 21 sandwiching the second connecting piece 23 is inserted into the leading guide roller 40. When applied, it is rotated around the rotation axis of the leading guide roller 40. Accordingly, the posture of the first connecting piece 21 at the rear is changed from the vertical posture to the horizontal posture. When the direction is changed from the vertical posture to the horizontal posture, the hook-shaped portions at the tips of the pair of hooks 211 of the rear first connecting piece 21 rotate along an arc centering on the connecting pin, and the first connecting portion on the rear side. At the same time as the top 21 is changed to the horizontal posture, the top 21 is already fitted into the holes of the pair of hooks 213 of the first connecting piece 21 in front of the horizontal posture. On the other hand, when the arm contracts, when the columnar body reaches the leading guide roller 40, the columnar body is rotated about the rotation axis of the leading guide roller 40. Thereby, the columnar body is turned from the horizontal posture to the vertical posture. When the direction is changed from the horizontal posture to the vertical posture, the hook-shaped portions at the tips of the pair of hooks 211 of the rear first connecting piece 21 are disengaged from the holes of the pair of hooks 213 of the front first connecting piece 21. As a result, the bending restrained state of the front and rear first connecting pieces 21 is released. The first connecting piece 21 released from the bending restrained state returns to a bendable state and is accommodated in the first support 11a in a vertical posture.

  When the first connecting piece 21 is stored, the tip end portion of the hook 213 of the front first connecting piece 21 overlaps the tip end portion of the hook 211 of the rear first connecting piece 21. When the front first connecting piece 21 is turned from the horizontal posture to the vertical posture as the arm portion 2 is pulled back due to the reverse rotation, the hook 213 of the front first connecting piece 21 is connected to the rear first connecting piece. The hook 211 of the top 21 is covered or the tip of the hook 213 of the front first connecting piece 21 contacts the tip of the hook 211 of the rear first connecting piece 21. Thereby, as shown in FIG. 2, the first and second connecting pieces 21, 23 are accommodated in the first support 11a while being slightly bent inward.

  FIG. 7 is a side view showing a bending restrained state of the first connecting piece 21 of FIG. In FIG. 7, a plurality of first connecting pieces 21 are shown together with the injection unit 30. Here, in order to explain the bending restrained state of the first connecting piece 21, the second connecting piece 23 is schematically shown. As shown in FIG. 7, the rear end portion of the columnar body is held by the upper part of the injection unit 30 and the lower rollers 31 and 32. The columnar body has a property that it cannot be bent outward due to the cross-sectional shape of the first and second connecting pieces 21 and 23. The columnar body is in a state in which the hook-shaped portions of the pair of hooks 211 of the rear first connecting piece 21 are fitted in the holes of the pair of hooks 213 of the front first connecting piece 21, and the rear end portion of the columnar body is the injection portion. By being held by 30, inward bending is restrained.

  Next, a mechanism for restraining the bending of the second connecting piece 23 will be described with reference to FIGS. FIG. 8 is a view showing a bending restraining / releasing mechanism of the second connecting piece 23 of FIG. Here, in order to explain the bending restraining mechanism of the second connecting piece 23, the first connecting piece 21 is schematically shown. As the arm portion 2 is sent out by the forward rotation of the drive gear 50, the second connecting piece 23 moves from the vertical posture shown in FIG. 8A to the posture shown in FIG. Turned to the horizontal posture shown. The front and rear second connecting pieces 23 are restrained from bending by engaging each other with the first connecting piece 21 therebetween. Specifically, as shown in FIG. 8, when the arm is extended, the rear second connecting piece 23 among the front and rear second connecting pieces 23 sandwiching the first connecting piece 21 is inserted into the leading guide roller 40. When applied, it is rotated around the rotation axis of the leading guide roller 40. As a result, the posture of the rear second connecting piece 23 is changed from the vertical posture to the horizontal posture. When the direction is changed from the vertical posture to the horizontal posture, the hook-shaped portion at the tip of the hook 231 of the rear second connecting piece 23 rotates along an arc centering on the rotation axis of the leading guide roller 40 and moves backward. At the same time as the second connecting piece 23 is changed to the horizontal posture, the second connecting piece 23 is already fitted into the hole of the hook 233 of the second connecting piece 23 in front of the horizontal posture. On the other hand, when the arm contracts, when the columnar body reaches the leading guide roller 40, the columnar body is rotated about the rotation axis of the leading guide roller 40. Thereby, the columnar body is turned from the horizontal posture to the vertical posture. When the direction is changed from the horizontal posture to the vertical posture, the hook-shaped portion at the tip of the hook 231 of the rear second connecting piece 23 is released from the hole of the hook 233 of the front second connecting piece 23. As a result, the bending restrained state of the front and rear second connecting pieces 23 is released. The second connecting piece 23 released from the bending restrained state returns to a bendable state and is accommodated in the first support 11a in a vertical posture.

  When the second connecting piece 23 is stored, the tip of the hook 233 of the second connecting piece 23 in the front overlaps with the tip of the hook 231 of the second connecting piece 23 in the rear, so that the drive gear 50 When the front second connecting piece 23 is turned from the horizontal posture to the vertical posture as the arm portion 2 is pulled back by the reverse rotation of the arm portion 2, the hook 233 of the front second connecting piece 23 is connected to the rear second connecting piece. The hook 231 of the top 23 is covered or the tip of the hook 233 of the second connecting piece 23 in front is in contact with the tip of the hook 231 of the second connecting piece 23 behind. Thereby, as shown in FIG. 2, the first and second connecting pieces 21, 23 are accommodated in the first support 11a while being slightly bent inward.

  FIG. 9 is a side view showing a bending restrained state of the second connecting piece 23 of FIG. In FIG. 9, a plurality of second connecting pieces 23 are shown together with the injection unit 30. Here, in order to explain the bending restrained state of the first connecting piece 21, the first connecting piece 21 is schematically shown. As shown in FIG. 9, the rear end portion of the columnar body is held by the upper part of the injection unit 30 and the lower rollers 31 and 32. The columnar body has a property that it cannot be bent outward due to the cross-sectional shape of the first and second connecting pieces 21 and 23. Further, the columnar body is held at the rear end portion thereof by the injection unit 30 in a state where the hook-shaped portion of the hook 231 of the rear second connection piece 23 is fitted in the hole of the hook 233 of the front second connection piece 23. As a result, the inward bending is restrained.

  According to the linear motion expansion / contraction mechanism of the robot arm mechanism according to the present embodiment described above, it is only necessary to change the direction of the first and second connection pieces 21 and 23 alternately connected in a row from a vertical posture to a horizontal posture. The bending of the arm part 2 can be restrained. Thereby, a columnar body having a certain rigidity can be configured. Further, the bending restrained state of the arm portion 2 can be released simply by changing the direction of the columnar body from the horizontal posture to the vertical posture. Thereby, the columnar body can be separated into the first and second connecting pieces 21 and 23. Specifically, when the first and second connecting pieces 21 and 23 change direction from the vertical posture to the horizontal posture, the front and rear first connecting pieces 21 are engaged with each other with the second connecting piece 23 interposed therebetween. The bending of the first connecting piece 21 is constrained, and the bending of the second connecting piece 23 before and after the second connecting piece 23 is restricted by the engagement of the second connecting pieces 23 before and after the first connecting piece 21. Thereby, the 1st, 2nd connection piece 21 and 23 comprise a columnar body, and the bending to the inner side is restrained because the rear-end part of a columnar body is hold | maintained at the injection part 30. FIG. The columnar body has a property that it cannot be bent outward due to the cross-sectional shape of the first and second connecting pieces 21 and 23. The columnar body has a certain rigidity by being restrained from bending inward and outward. When the columnar body changes its direction from a horizontal posture to a vertical posture, the engagement state between the front and rear first and second connecting pieces 21, 23 is released, so that the bending restrained state is also released. Thereby, the 1st, 2nd connection piece 21 and 23 return to the state which can be bent individually.

  In order to change the direction of the first and second connecting pieces 21 and 23 (arm portion 2) alternately connected in a row, the guide roller 40 of the conveying portion is disposed between the injection portion 30 and the first support 11a. This can be easily realized. That is, the linear motion expansion / contraction mechanism of the robot arm mechanism according to the present embodiment can realize a columnar body having a constant rigidity with a simple configuration.

(Modification 1)
FIG. 10 is a side view showing the storage portion of the robot arm mechanism according to the first modification of the present embodiment. In the first modification, the second support 11b is a box-shaped body having a side shape in which a semicircle and a quadrangle are combined. The second support member 11b is supported on the first support member 11a so as to be rotatable around the first and second rotation axes RA1 and RA2, that is, swingable and undulating, and the arm portion 2 swivels together with the second support member 11b. , Will be undulated again. In Modification 1, since the arm portion 2 is housed inside the second support body 11b, the second support body 11b is also referred to as a housing section.

  A circular or polygonal reel 13 for winding the first and second connecting pieces 21 and 23 inside is accommodated inside the second support 11b. The last connecting piece 21 or 23 of the arm unit 2 is connected to the circumferential surface of the reel 13. The rotation axis of the reel 13 is arranged in parallel with the second rotation axis RA2. The rotation of the reel 13 is driven by a motor 55. Typically, the motor 55 is shared by both drives as a common actuator for the reel 13 and the drive gear 50. The rotation shaft of the reel 13 is connected to the drive shaft of the motor 55 via a speed reducer or a belt mechanism, and the reduction ratio is adjusted so that the arm portion 2 is sent out and wound up in conjunction with the arm expansion / contraction speed. The first and second connecting pieces 21 and 23 separated by the leading guide roller 40 are accommodated in the second support 11b while being rounded into an arc shape by the reel 13. As described above, the first and second connecting pieces 21 and 23 are rolled and stored in an arc shape, so that the hook 213 of the first connecting piece 21 on the front side and the hook 211 of the first connecting piece 21 on the rear side are arranged. Interference and interference between the hook 233 of the front second connecting piece 23 and the hook 231 of the rear second connecting piece 23 can be avoided, and the storage space length can be shortened.

(Modification 2)
FIG. 11 is a perspective view showing the arm portion 2 of the robot arm mechanism according to the second modification of the present embodiment. FIG. 12 is a diagram showing the first connection piece 21 of FIG. FIG. 13 is a diagram showing the second connection piece 23 of FIG. Out of the first connecting pieces 21 that move back and forth across the second connecting piece 23, a hook-shaped portion at the tip of the hook 211 of the first connecting piece 21 at the rear and a receiving hole portion of the hook 213 of the first connecting piece 21 at the front. Means that the protrusion length L12 of the hook 211 protruding to the front of the first main body portion 210 and the hook protruding to the rear of the first main body portion 210 can be configured so as to overlap the upper portion of the main body portion 230 of the second connecting piece 23. The protruding length L13 of 213 may not be the same length.

  For example, as shown in FIGS. 11 and 12, the protruding length L12 of the pair of hooks 211 protruding forward of the first body portion 210 is less than ½ of the length L21 of the second body portion 230, The protrusion length L13 of the pair of hooks 213 protruding rearward of the first main body portion 210 may be configured. Similarly, as shown in FIGS. 11 and 13, the protruding length L22 of the pair of hooks 231 protruding forward with respect to the second body portion 230 is less than ½ of the length L11 of the first body portion 210. And it may be comprised shorter than the protrusion length L23 of a pair of hook 233 which protrudes back with respect to the 2nd main-body part 230. FIG. Thus, by shortening the hook length protruding forward of the first and second connecting pieces 21 and 23, the first and second connecting pieces 21 and 23 are rotated when the leading guide roller 40 is rotated. The space above the second support 11b can be reduced. Further, by shortening the hook length protruding forward of the first and second connecting pieces 21 and 23, the hook when the first and second connecting pieces 21 and 23 rotate around the leading guide roller 40 is used. The moment of force of the hooked portions of 211 and 231 can be reduced, and the load and fitting noise when the hooked portions of the hooks 211 and 231 are fitted into the holes of the hooks 213 and 233 can be reduced. .

  Although not shown, the protrusion length L13 of the pair of hooks 213 protruding rearward of the first body portion 210 is less than ½ of the length L21 of the second body portion 230, and It may be configured to be shorter than the protruding length L12 of the pair of hooks 211 protruding forward. Similarly, the protruding length L23 of the pair of hooks 233 protruding backward with respect to the second main body portion 230 is less than ½ of the length L11 of the first main body portion 210, and is smaller than the second main body portion 230. The pair of hooks 231 protruding forward may be configured to be shorter than the protruding length L22. Thus, by shortening the hook length protruding rearward of the first and second connecting pieces 21, 23, for example, the first and second connecting pieces 21, 23 rotate around the leading guide roller 40. The space behind the second support 11b can be reduced.

  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 ... Linear motion joint part, 11a ... 1st support body (accommodating part), 11b ... 2nd Support body, 11c ... 3rd support body, 21 ... 1st connection top, 23 ... 2nd connection top

Claims (9)

In a robot arm mechanism having a rotary joint and a linear motion telescopic joint,
The direct acting telescopic joint is
A plurality of connecting pieces that are connected flexibly on the back side, and a columnar body is configured by bending restraint of the connecting pieces,
A support portion for supporting the columnar body;
A storage unit that stores the bent connection piece in a direction different from the support unit;
A transport unit that transports the connecting piece between the support unit and the storage unit;
The connecting pieces are provided in two types of first and second shapes having different shapes, and the first and second connecting pieces are alternately arranged,
The first connecting pieces are provided with first hooks on the front and rear sides of the front side, respectively, and the first connecting pieces on the front and rear sides are engaged by the first hooks on the front and rear sides with the second connecting piece interposed therebetween. Is restrained to be bent, and returned to the bent state by disengaging the front and rear first hooks;
The second connecting pieces are provided with second hooks on the front and rear sides of the front side, respectively, and the front and rear second connecting pieces are engaged by the front and rear second hooks sandwiching the first connecting piece therebetween. It is bent and restrained, and is returned to the bent state by disengaging the front and rear second hooks,
The robot arm mechanism according to claim 1, wherein the bending restrained state / bending state of the first and second connecting pieces is changed by changing the direction between the support part and the storage part. The first hook is provided on each of the upper left and right of the first main body portion having the cylindrical body of the first connection piece,
The robot arm mechanism according to claim 1, wherein the second hook is provided at an upper center of a second main body portion having a cylindrical body of the second connecting piece. The total length of the first hooks before and after the first connecting piece is longer than the length of the second main body portion of the second connecting piece,
The robot arm mechanism according to claim 2, wherein a total length of the second hooks before and after the second connecting piece is longer than a length of the first main body portion. The first hooks before and after the first connecting piece have different lengths,
The robot arm mechanism according to claim 3, wherein the second hooks before and after the second connecting piece have different lengths. The first hook behind the first connecting piece is longer than the first hook in front of the first connecting piece,
5. The robot arm mechanism according to claim 4, wherein the second hook behind the second connecting piece is longer than the second hook in front of the second connecting piece. The first and second body portions have a rectangular cross section,
The robot arm mechanism according to claim 2, wherein the first and second main body portions and the first and second hooks are formed so that an upper surface of the columnar body forms a plane.   3. The robot arm mechanism according to claim 2, wherein the second main body portion has the same outer shape as the first main body portion.   3. The robot arm mechanism according to claim 2, wherein the second main body portion has the same length as the first main body portion.   The robot arm mechanism according to claim 1, wherein the storage unit includes a winding unit that winds up the first and second connecting pieces.

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