TW201741098A - Linear extension and retraction mechanism - Google Patents

Abstract

The purpose of the present invention is to reduce the replacement frequency of first and second pieces that are critical components of a linear extension/retraction mechanism. A linear extension/retraction mechanism that has: a plurality of flat, flexibly connected first pieces 53; and a plurality of half-pipe-shaped, flexibly connected second pieces 54. Heads of the plurality of first pieces and heads of the plurality of second pieces are joined by a joining part 55. A support mechanism part 58 supports the first and second pieces such that the first and second pieces can move forward and backward, makes the first and second pieces adjoin when the first and second pieces move forward, and makes the first and second pieces separate when the first and second pieces move backward. The first and second pieces form a stiff straight line when adjoined and return to a flexible state when separated. Abrasion prevention pads 550 that comprise a softer material than the first and second pieces and that are for preventing abrasion at contact surfaces of the first and second pieces at which the first and second pieces contact each other are mounted at one section of the contact surfaces of the first and second pieces.

Description

Direct motion telescopic mechanism

Embodiments of the present invention relate to a linear motion expansion mechanism.

Since the prior art, the multi-joint robot arm mechanism has been used in various fields such as industrial robots. The inventors and the like have developed a linear motion expansion mechanism that can be applied to such a multi-joint mechanical arm mechanism (Patent Document 1). The linear motion retracting mechanism has a plurality of links (first links) made of a metal having a flat plate shape that are bendably connected by a hinge structure, and a plurality of metal members having a half-angle tube shape that is bendably connected to the bottom plate by a hinge. Chain links (second chain links). The first and second links are coupled at the front end. When the front and the second links are fed forward, the first and second links are overlapped to ensure a rigid straight state, and the columnar arm having a certain rigidity is formed. When pulled back toward the rear, the first and second links are separated, respectively, and returned to a bendable state, and are housed inside the pillar. The use of the linear motion mechanism to the multi-joint robot mechanism eliminates the need for an elbow joint and can easily eliminate the critical point, so that it is a very advantageous structure.

It is required to firmly join the first and second links to increase the rigidity of the arms. The first and second links are repeated with each other for strong collision with the expansion and contraction of the arms. hit. Therefore, the contact faces of the first and second links are inevitably worn. Wear of the contact surface reduces the rigidity of the arm. Therefore, the worn first and second links need to be replaced as soon as possible.

Since the replacement of the first and second links is due to the internal structural components of the chain links, it is necessary to disassemble the arm mechanism, which requires a lot of man-hours. Further, the first and second link metal-cut products have a relatively high cost.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5435679

It is an object of the present invention to reduce the frequency of replacement of the first and second links as important components of the linear motion retractable mechanism.

The linear motion stretching mechanism according to the present embodiment has a plurality of first links that are bent in a flat plate shape and a plurality of second links that are bendably connected to each other. The foremost end of the plurality of first links and the foremost end of the plurality of second links are joined by the joint. The support mechanism unit supports the first and second link sections in a freely movable manner, and causes the first and second link links to engage each other when moving forward, and when the first and second links move backward, Separate. When the first and second links are joined to each other, they are straight and straight, and when the first and second links are separated from each other, they return to a curved state. Yu Di 1. at least a portion of the at least one contact surface of the first and second links in contact with each other or at least one contact point, wherein the material hardness is installed in order to prevent wear of the contact surfaces of the first and second links An abrasion resistant pad that is lower than the first and second links, and/or coated with a coating agent.

54‧‧‧second chain link

540‧‧‧ side panels

541‧‧‧floor

542‧‧‧Support block

543‧‧‧ bearing blocks

544, 545‧‧‧ shaft holes

546‧‧‧Lock pin

547‧‧‧Lock pin

548‧‧‧ chuck block

550‧‧‧ wear pad

Fig. 1 is a perspective view showing the appearance of a mechanical arm mechanism equipped with the linear motion stretching mechanism of the embodiment.

Figure 2 is a side elevational view of the robotic arm mechanism of Figure 1.

Fig. 3 is a side view showing the internal structure of the mechanical arm mechanism of Fig. 1.

Fig. 4 is a view showing the configuration of the mechanical arm mechanism of Fig. 1 by the symbol representation.

Figure 5 is a diagram showing the first link of Figure 3.

Figure 6 is a view showing the second link of Figure 3.

Fig. 7 is a perspective view showing the wear pad of the second link attached to Fig. 6.

Fig. 8 is a view for explaining a joining process of the first and second links of Fig. 3.

Figure 9 is a view for explaining the joining process of the locking mechanism of Figure 8.

Fig. 10 is a view showing a portion of a film formed by using an anti-wear agent.

Hereinafter, the linear motion expansion mechanism of this embodiment will be described with reference to the drawings. In addition, the linear motion expansion mechanism of the embodiment can be used as a separate The mechanism (joint) is used. In the following description, a robot arm mechanism of a polar coordinate type constituted by one of a plurality of joint portions by a linear motion expansion mechanism according to the present embodiment will be described as an example. The linear motion expansion mechanism of this embodiment can also be applied to a cylindrical coordinate type robot arm mechanism. Of course, the linear motion expansion mechanism of the present embodiment can also be applied to a mechanism other than the robot arm mechanism. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and the description will be repeated only when necessary.

Fig. 1 is a view showing the appearance of a mechanical arm mechanism equipped with the linear motion stretching mechanism of the embodiment. Figure 2 is a side elevational view of the robotic arm mechanism of Figure 1. Fig. 3 is a side view showing the internal structure of the mechanical arm mechanism of Fig. 1. The arm mechanism includes a base 1, a turning portion (pillar portion) 2, a shoulder portion 4, an arm portion 5, and a wrist portion 6. The turning portion 2, the shoulder portion 4, the arm portion 5, and the wrist portion 6 are sequentially disposed from the base 1. The turning portion 2, the shoulder portion 4, and the arm portion 5 correspond to the joint portions J1, J2, and J3, respectively. The wrist portion 6 is assembled with joint portions J4, J5, and J6. The convoluted portion 2 of the cylindrical body formed on the susceptor 1 is typically provided vertically. The turning portion 2 houses the first joint portion J1. The first joint portion J1 is a rotational joint that rotates around the rotation axis RA1. The rotating shaft RA1 is parallel to the vertical direction. The turning portion 2 has a lower frame 21 and an upper frame 22. One end of the lower frame 21 is connected to the fixing portion of the first joint portion J1. The other end of the lower frame 21 is connected to the base 1. The lower frame 21 is covered by a cylindrical casing 31. The upper frame 22 is connected to the rotating portion of the first joint portion J1, and pivots about the rotation axis RA1. The upper frame 22 is covered by a cylindrical casing 32. As the first joint portion J1 rotates, the upper frame 22 rotates relative to the lower frame 21, whereby the arm portion 5 revolves. Forming a cylinder The first and second link rows 51 and 52 of the third joint portion J3, which will be described later as a linear motion expansion mechanism, are hollowly accommodated inside the turning portion 2.

A shoulder portion 4 is provided on the upper portion of the turning portion 2. The shoulder portion 4 is provided with a second joint portion J2 as a rotary joint. The arm portion 2 is rotated about its rotation axis RA2 by the rotation of the second joint portion J2. The rotation axis RA2 of the second joint portion J2 is orthogonal to the rotation axis RA1. The shoulder portion 4 has one side frame 23 as one of the fixing portions (support portions) of the second joint portion J2. The pair of side frames 23 are coupled to the upper frame 22. The pair of side frames 23 are covered by a saddle-shaped outer cover 33. A cylindrical body 24 serving as a rotating portion of the second joint portion J2 that also serves as a motor housing is supported by the pair of side frames 23. A support mechanism 25 is attached to the circumferential surface of the cylindrical body 24. The support mechanism 25 is covered by a cylindrical outer cover 34. The gap between the saddle cover 33 and the cylindrical outer cover 34 is covered by a U-shaped bellows outer cover 14 having a U-shaped cross section. The U-shaped corona cover 14 is stretched and contracted following the undulating movement of the second joint portion J2. The support mechanism 25 holds the drive gear 56, the guide roller 57, and the roller unit 58. The roller unit 58 has a plurality of rollers 59 and is disposed in front of the support mechanism 25. A drive gear 56 is disposed behind the roller unit 58. The drive gear 56 is connected to a motor unit (not shown). The motor unit generates power for rotating the drive gear 56. A linear gear 539 of the first link 53 is engaged with the drive gear 56. The linear gear 539 is formed on the inner side of the first link 53, and in other words, the center of the width of the side joined to the second link 54, and is formed along the connecting direction. When the plurality of first links 53 are linearly aligned, the adjacent linear gears 539 are linearly connected to form a long linear gear. The linearly connected linear gears 539 are combined with the drive gears 56 to form gear teeth. Article agency. Above the drive gear 56, the guide rollers 57 are disposed at a distance substantially equivalent to the thickness of the first link 53. Thereby, the drive gear 56 is meshed with the linear gear 539 of the first link 53 pressed by the guide roller 57, and the smooth transmission of the first link row 51 is realized by the drive gear 56. As the shaft of the cylindrical body 24 rotates, the support mechanism 25 rotates to rotate the arm portion 5 supported by the support mechanism 25 upward or downward.

The third joint portion J3 is a linear motion extending and retracting mechanism. The linear motion expansion mechanism has a newly developed structure by the inventors and the like, and the movable range is clearly longer than the previous prismatic joint. The arm portion 5 of the third joint portion J3 is freely bendable, but when the center shaft (the telescopic center axis RA3) is fed forward from the support portion 25 of the root portion of the arm portion 5, the bending thereof is restricted to ensure linear rigidity. The bending is resumed when the arm portion 5 is pulled back toward the rear. The arm portion 5 has a first chain link row 51 and a second chain link row 52. The first link row 51 includes a plurality of first links 53 that are freely coupled. Each of the first links 53 is formed in a substantially flat shape. The plurality of first links 53 are bent and connected in a row by a plurality of hinge portions. Each of the hinge portions connects the adjacent pair of first links 53 to each other at their ends. The second chain link row 52 includes a plurality of second links 54. Each of the second links 54 has a tube having a circular or polygonal cross-sectional shape or a half tube shape thereof. That is, the half pipe shape is either a semicircular pipe shape or a half pipe shape. Typically, each of the second links 54 is in the shape of a half-corner in which the bottom plate and the two side plates are combined at right angles. The plurality of second links 54 are flexibly connected in a row by a plurality of hinge portions. Each hinge portion is such that the adjacent pair of second links 54 are at the bottom of the pair The ends of the plates are connected to each other. The bending of the second link row 52 is locked at a position where the end faces of the side plates of the second link 54 abut each other. At this position, the plurality of second link rows 52 are arranged in a straight line. The first link 53 at the foremost end of the first link row 51 and the second link 54 at the foremost end of the second link row 52 are connected by a joint link 55. For example, the joint link 55 has a shape in which the first link 53 and the second link 54 are combined.

The first and second link rows 51, 52 are pressed and joined to each other by the roller 59 when passing through the roller unit 58 of the support mechanism 25. The first and second link rows 51 and 52 are linearly rigid by joining, and constitute a columnar arm portion 5. When the drive gear 56 rotates in the forward direction, the first and second link rows 51, 52 form a columnar body and are sent forward. When the drive gear 56 is rotated in the reverse direction, the columnar body is pulled back, and the first and second link rows 51, 52 are separated between the roller unit 58 and the drive gear 56. The separated first and second link rows 51, 52 are restored to a bendable state, respectively. The first and second link rows 51 and 52 that have returned to the bendable state are all bent in the same direction (inside), and are vertically housed inside the turning portion 2. At this time, the first link row 51 is accommodated in a substantially aligned state substantially in parallel with the second link row 52.

A wrist portion 6 is attached to the front end of the arm portion 5. The wrist 6 is equipped with fourth to sixth joint portions J4 to J6. The fourth to sixth joint portions J4 to J6 each have orthogonal three-axis rotation axes RA4 to RA6. The fourth joint portion J4 is a rotary joint that rotates around the fourth rotation axis RA4 that substantially coincides with the expansion center axis RA3, and the end effector swings by the rotation of the fourth joint portion J4. The fifth joint portion J5 is fifth in orthogonality with the fourth rotation axis RA4 The rotating joint RA5 is a rotating joint that rotates at the center. The end effector tilts back and forth by the rotation of the fifth joint portion J5. The sixth joint portion J6 is a rotary joint that rotates around the sixth rotation axis RA6 orthogonal to the fourth rotation axis RA4 and the fifth rotation axis RA5. The end effector shaft rotates by the rotation of the sixth joint portion J6.

The end effector (end effector) is attached to the adapter 7 provided at the lower portion of the rotating portion of the sixth joint portion J6 of the wrist portion 6. The end effector has a function of allowing the robot to directly act on the work object (workpiece), and for example, there are a retaining portion, a vacuum suction portion, a nut fastener, a welding gun, a spray gun, and the like, depending on the task. The end effector is moved to an arbitrary position by the first, second, and third joint portions J1, J2, and J3, and is disposed in any posture by the fourth, fifth, and sixth joint portions J4, J5, and J6. . In particular, the length of the telescopic distance of the arm portion 5 of the third joint portion J3 allows the end effector to reach a wide range of objects from the proximal position of the base 1 to the remote position. The third joint portion J3 is characterized in that the linear telescopic movement realized by the linear motion expansion mechanism constituting the third joint portion J3 and the length of the telescopic distance thereof are different from the previous direct motion joint.

Fig. 4 is a view showing the configuration of the mechanical arm mechanism by the symbol representation. In the arm mechanism, three positional degrees of freedom are realized by the first joint portion J1, the second joint portion J2, and the third joint portion J3 which constitute the three axes of the root. Further, three posture degrees of freedom are realized by the fourth joint portion J4, the fifth joint portion J5, and the sixth joint portion J6 which constitute the three axes of the wrist. As shown in FIG. 4, the rotation axis RA1 of the first joint portion J1 is provided in the vertical direction. The rotation axis RA2 of the second joint portion J2 is provided in the horizontal direction. Second joint J2 phase The first joint portion J1 is offset in two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1. The rotation axis RA2 of the second joint portion J2 does not intersect the rotation axis RA1 of the first joint portion J1. The movement axis RA3 of the third joint portion J3 is oriented perpendicular to the rotation axis RA2. The third joint portion J3 is offset from the second joint portion J2 in two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1. The rotation axis RA3 of the third joint portion J3 does not intersect the rotation axis RA2 of the second joint portion J2. One of the three joints of the roots of the plurality of joint portions J1 - J6 is replaced by a linear motion joint portion J3. The second joint portion J2 is displaced in two directions with respect to the first joint portion J1. The third joint portion J3 is displaced in two directions with respect to the second joint portion J2. Thereby, the mechanical arm mechanism of the present embodiment achieves the critical point elimination.

(first link 53)

Fig. 5 is a view showing the configuration of the first link 53 of Fig. 3. The first link 53 as a whole is a substantially flat body. The first link 53 is formed by integrally forming a pair of support blocks 532 and bearing blocks 533 on the main body portion 531 of the flat rectangular shape. A pair of support blocks 532 are protruded forward from both sides of the front end of the body portion 531. The bearing block 533 is protruded rearward from the center of the rear end of the body portion 531. A pair of shaft holes 534 are passed through the support block 532 at the front end in parallel with the width direction of the first link 53. The bearing block 533 at the rear end also penetrates the shaft hole 535 in parallel with the width direction of the first link 53. In a state in which one of the front ends of the first link 53 is opposite to the support block 532 and the bearing block 533 at the rear end of the other first link 53 is embedded, a pair The shaft hole 534 is continuously connected to the shaft hole 535. A shaft (not shown) is inserted into the continuous through hole, and the first links 53 are rotatably coupled to each other. A linear gear 539 is provided at the center of the width of the back surface of the first link 53 in parallel with the connection direction (longitudinal direction). A linear gear 539 is disposed at the center of the back surface of the first link 53 over the front and rear, and a pair of protrusions (pin hole blocks) 536 having a quadrangular frustum shape are vertically protruded on both sides of the back surface. A pair of pin hole blocks 536 are located on both sides near the center in the front and rear direction (longitudinal direction) of the first link 53. A locking pin hole 537 is formed in the pin hole block 536 along the front-rear direction thereof.

In FIG. 5, the contact surface of the first link 53 which is in contact with the second link 54 in a state in which the first and second links 53, 54 are joined is indicated by oblique lines. As shown in FIG. 5, the contact faces of the first link 53 are the back side portions of the first link 53, the front end face and the rear end face of the pin hole block 536.

(second link 54)

Fig. 6 is a view showing the configuration of the second link 54 of Fig. 3. The second link 54 is in the shape of a half-angle tube. The second link 54 includes a bottom plate 541 and one side plate 540 of the same size and shape. A pair of support blocks 542 are protruded from both sides of the front end of the bottom plate 541. A bearing block 543 is protruded from the center of the rear end of the bottom plate 541. A pair of shaft holes 544 are penetrated through the support block 542 at one of the front ends in parallel with the width direction of the second link 54. The bearing block 543 at the rear end also passes through the shaft hole 545 in parallel with the width direction of the second link 54. A pair of the bearing block 543 at the rear end of the other second link 54 is interposed between one of the front ends of the second link 54 and the support block 542. The shaft hole 544 is continuously connected to the shaft hole 545. The continuously inserted through holes are inserted into the shaft, and the front and rear second links 54 are rotatably coupled to each other. A locking pin block 546 is protruded inwardly from the front end of each of the side plates 540 of the second link 54 toward the inner side. The lock pin block 546 is formed in a rectangular parallelepiped shape, and a lock pin 547 is provided on a front side surface thereof. The lock pin 547 is formed in a cylindrical shape and protrudes forward in parallel with the joining direction. A chuck block 548 is protruded toward the inner side of the rear end portion of each of the side plates 540 of the second link 54. The chuck block 548 is formed in a quadrangular frustum shape with its inclined surface facing rearward. In the second chain link row 22, the chuck block 548 of the front second link 54 is combined with the locking pin block 546 of the second chain link 54 at the rear to form a receiving portion of the front and rear receiving pin hole block 536.

In Fig. 6, the contact faces of the second links 54 which are in contact with the first link 53 in a state in which the first and second links 53, 54 are joined are indicated by oblique lines. As shown in FIG. 6, the contact faces of the second links 54 are the upper end faces of the pair of side plates 540, the front end faces of the locking pin blocks 546, and the rear end faces of the chuck block 548.

(locking mechanism)

The linear motion retracting mechanism has a locking mechanism for firmly holding the engaged state of the first and second links 53, 54. The locking mechanism is formed by a chuck block 548 of the second link 54 and a locking pin block 546, and a pin block 536 of the first link 53.

When the arm portion 5 is extended, the pin portions 536 of the first link 53 are sandwiched by the receiving portions of the front and rear second links 54, whereby the first and second links 53, 54 are engaged. The joint state of the first and second links 53, 54 is The pin hole 537 of the first link 53 is inserted into the state in which the locking pin 547 of the second link 54 is inserted. The locking pin 547 of the second link 54 is inserted into the first link 53 when the second link 54 passes through the last roller 59 of the roller unit 58 and is linearly aligned with respect to the second link 54 at the front thereof. Pin hole 537. In a state in which the pin hole 537 of the first link 53 is inserted with the lock pin 547 of the second link 54, the front and rear second links 54 are linearly aligned, that is, the rear end portion of the arm portion 5 is covered by the roller unit 58. Maintain a state of solid maintenance.

When the arm portion 5 is contracted, behind the roller unit 58, the second link 54 is restored to a bendable state, and gravity is pulled downward. On the other hand, the first link 53 is pulled rearward by the drive gear 56 in a state of maintaining a horizontal posture. The second link 54 is pulled downward, and the first link 53 is pulled rearward, whereby the locking pin 547 of the second link 54 is pulled out from the pin hole 537 of the first link 53 and the second link is forward and backward. The receiving portion of 54 opens the pin hole block 536 of the first link 53 whereby the joined state of the first and second links 53, 54 is released, and is bendably separated from each other.

As described above, the expansion and contraction of the arm portion 5 constituting the linear motion expansion mechanism is realized by the fact that the first and second links 53 and 54 are fed away from each other when engaged and pulled back. When the first and second links 53, 54 are engaged, the second link 54 collides with the first link 53, whereby the contact faces of the first and second links 53, 54 are worn. Further, in a state in which the first and second links 53 and 54 are joined, the link portion is slightly vibrated due to the expansion and contraction movement of the arm portion 5, and the contact surface is worn. The wear of the contact faces of the first and second links 53, 54 changes the outer dimensions of the first and second links 53, 54. First and second links 53, 54 The change in size may lower the rigidity of the arm portion 5 and hinder the linearity of the arm portion 5. The linear motion expansion mechanism of the present embodiment reduces the wear of the contact faces of the first and second links 53, 54. Specifically, the wear pad is attached to at least a portion of at least one of the contact faces of the first link 53 and the contact surface of the second link 54. A coating agent is applied to at least a part of at least one of the contact faces of the contact surface of the first link 53 and the second link 54 together with or in place of the wear pad.

Fig. 7 is a perspective view showing the wear pad of the first link 53 attached to Fig. 3. As shown in FIG. 7, the wear pad 550 is preferably mounted on the side of the rear side of the chuck block 548. The wear pad 550 is, for example, in the shape of a disk, and is attached to the chuck block 548 by adhesion or the like. The wear pad 550 is compared to the surface hardness of the first and second links 53, 54 , that is, the surface coating of the raw material (for example, an AlCu-based aluminum alloy) or the first and second links 53 , 54 (for example, hard corrosion protection) Aluminum layer) Made of metal or resin with low hardness. In the case of a resin, in addition to natural rubber, a fluorine resin such as polytetrafluoroethylene having a low friction coefficient and high durability, an ultrahigh molecular weight high density polyethylene, and a polyacetal or polyamide as a self-lubricating resin may be used. Polytetrafluoroethylene, etc. The collision, contact, and sliding of the first and second links 53, 54 preferentially wear the wear pad 550 of the material having a lower hardness than the first and second links 53, 54.

Fig. 8 is a view for explaining a joining process of the arm portion 5 of Fig. 3. Fig. 9 is a schematic view showing the lock mechanism of Fig. 8. 9(a), (b) and (c) are schematic views showing the locking mechanism of Figs. 8(a), (b) and (c), respectively. As shown in FIG. 8(a), FIG. 8(b), FIG. 9(a), and FIG. 9(b), when the second link 54-1 is displaced from the bent state to the straight state, The rear side of the chuck block 548-1 of the second link 54-1 will collide with the front side of the pin block 536-1 of the first link 53-1, whereby the contact surface is worn. Further, as shown in FIGS. 8(c) and 9(c), when the rear second link 54-2 is displaced from the bent state to the straight state, the rear second link 54-2 is locked. 546-2 collides with the pin hole block 536-1 of the first link 53-1, the pin hole block 536-1 of the first link 53-1 is pressed forward, and the front side thereof presses the second link 54-1. The side of the rear of the chuck block 544-1. Since the rear side of the chuck block 544-1 and the front side of the pin hole block 536-1 are inclined with respect to the telescopic shaft RA3, the front side of the pin hole block 536-1 is opposite to the rear side of the chuck block 544-1. Sliding and abrasion.

Thus, the joint strength between the front side of the pin block 536 of the first link 53 and the rear side of the chuck block 548 of the second link 54 is higher than the joint strength of the other contact faces, and the stress per unit area High, so it wears faster than other contact surfaces. The wear pad 550 is attached to the side of the second block 54 after the chuck block 548, which most effectively reduces the wear of the contact faces of the first and second links 53, 54. Specifically, on the side after the chuck block 548 of the second link 54, the wear pad 550 prevents wear on the rear side of the chuck block 548 of the second link 54 and reduces the pin block of the first link 53. The wear of the side of the 536 side. Moreover, the wear pad 550 alleviates the impact of the second link 54 colliding with the first link 53, and also reduces the wear of other contact faces. Further, the wear pad 550 functions as a slip preventing member, and the sliding wear of the contact faces of the first and second links 53 and 54 is reduced.

In addition, the mounting position of the wear pad 550 is not limited to this. E.g, The wear pad 550 can also be mounted to the front side of the pin block 536 of the first link 53. In this case, the same effect as when the wear pad 550 is attached to the side surface behind the chuck block 548 of the second link 54 is obtained. Further, the locking mechanism can be maintained in a state in which the pin hole 537 of the first link 53 is inserted into the locking pin 547 of the second link 54, and the first and second links 53, 54 are engaged with each other. The rear side of the block 548 may not be in contact with the front side of the pin hole block 536. Therefore, the wear pad 550 is attached to the side of the rear side of the chuck block 548 of the second link 54 or the front side of the pin block 536 of the first link 53, and the wear pad 550 is attached to the other contact surface. In comparison, the shape of the link is not affected, and the performance of the arm portion 5 when the wear pad 550 is worn is also reduced. Of course, the wear pad 550 can also be mounted on the contact surface of the first and second links 53, 54 beyond the side of the chuck block 548 and the front side of the pin hole block 536.

Moreover, in order to reduce the wear of the first and second links 53, 54 , at least one of at least one of the contact faces of the first link 53 and the second link 54 may be coated against at least one of the contact faces. The abrading agent is typically a resin coating agent, preferably a resin coating agent containing fluorine as a main component, for example, HANARL (registered trademark). Fig. 10 is a view showing a portion of a film formed by the wear-resistant agent 553. As shown in FIG. 10, for example, a resin coating agent 553 may be applied to the entire surface of the contact surface of the second link 54.

Further, a plurality of sharp protrusions may be formed on at least one of the contact surface of the first link 53 and the contact surface of the second link 54, and the front ends (contact points) of the sharp protrusions may be in contact with each other. A tiny anti-wear pad or a coating agent may also be applied to the front end of at least one of the sharp protrusions.

The embodiments of the present invention have been described, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other forms, and various omissions, substitutions and changes can be made without departing from the scope of the invention. The scope of the invention and the scope of the invention are intended to be included in the scope of the invention and the equivalents thereof.

540‧‧‧ side panels

542‧‧‧Support block

543‧‧‧ bearing blocks

544, 545‧‧‧ shaft holes

546‧‧‧Lock pin

548‧‧‧ chuck block

550‧‧‧ wear pad

Claims (8)

A linear motion expansion mechanism comprising: a plurality of first links in a plate shape that is bendably coupled; a plurality of second links that are bendably connected in a tube shape or a half pipe shape; and a joint portion that will The front end of the plurality of first links is coupled to the foremost end of the plurality of second links; and the support mechanism portion movably supports the first and second links before and after, and when the first When the second link moves forward, the first link and the second link are linearly rigid and the second link is joined to the first link, and when the first link and the second link move rearward, The first and second links are restored to a curved state to separate the second link from the first link; and at least one of the first and second links that the first and second links are in contact with each other At least a portion or at least one contact point of the contact surface is provided with an anti-wear pad having a material hardness lower than that of the first and second links, and/or a coating for preventing wear of the contact faces of the first and second links The cloth has a paint. The linear motion expansion and contraction mechanism of claim 1, wherein a protrusion of a quadrangular frustum shape is provided on a surface of the first link on a side joined to the second link, and a rear end of the second link Provided in each of the receiving portions for engaging the protruding portion on the front and rear side surfaces thereof, wherein the receiving portion of the second link before and after the second link is sandwiched from the front and rear sides during the joining of the second link to the first link Protrusion, The wear-receiving pad is attached to the surface of the receiving portion provided at the rear end of the second link on the surface in contact with the front side of the protruding portion, and/or the coating agent is applied. The linear motion expansion and contraction mechanism of claim 1, wherein a protrusion of a quadrangular frustum shape is provided on a surface of the first link on a side joined to the second link, and a rear end of the second link Provided in each of the receiving portions for engaging the protruding portion on the front and rear side surfaces thereof, wherein the receiving portion of the second link before and after the second link is sandwiched from the front and rear sides during the joining of the second link to the first link The protrusion is attached to the side surface of the protrusion before the wear pad and/or the coating agent is applied. The linear motion stretching mechanism of claim 1, wherein the coating agent is applied to the entire surface of at least one of the contact surfaces of the first and second links. The linear motion retractable mechanism of claim 1, wherein the anti-wear pad is a resin pad. The linear motion retractable mechanism of claim 1, wherein the anti-wear pad is a metal pad. The linear motion stretching mechanism of claim 1, wherein the coating agent is mainly composed of fluorine. The linear motion retractable mechanism of claim 1, wherein the anti-wear pad is disc-shaped.