JP7391775B2 - Arm-like structures and robots - Google Patents

Description

The present disclosure relates to an arm-like structure and a robot.

In order to maintain strength while reducing weight, an arm for an industrial robot is known to have a structure in which a long arm body made of resin is provided with mounting interface sections at both ends (for example, see Patent Document 1). ).

Japanese Patent Application Publication No. 2018-176337

A structure in which an arm-like structure is integrally molded from resin with a hollow mounting interface section provided at a position that closes both ends of an arm main body configured in a hollow pipe shape requires some ingenuity in removing the core. Further, it is also necessary to devise ways to accurately form the attachment surfaces of the metal members provided apart from each other at both ends of the arm body made of resin. Therefore, it is desired to easily form an arm-like structure having a hollow structure with both ends closed or substantially closed, and to form mounting surfaces at both ends easily and accurately.

One aspect of the present disclosure includes a first part that is elongated and is made of resin and has a groove-shaped recess that opens in one direction intersecting the longitudinal direction and an opening that opens in the other direction. , a second part disposed at a position to close the opening of the recess and joined to the first part, the second part being an attachment part disposed at both ends of the longitudinal direction, the robot The arm-shaped structure is provided with a pair of attachment portions that are respectively fixed to other parts constituting the structure, and is attached to the other parts with the first part and the second part fixed to each other.

FIG. 1 is a perspective view showing an arm-like structure according to an embodiment of the present disclosure. FIG. 2 is a front view showing a first portion of the arm-like structure of FIG. 1; FIG. 2 is a side view showing a first portion of the arm-like structure of FIG. 1; FIG. 2 is a perspective view of the front side of the main body of the first portion of the arm-like structure of FIG. 1; FIG. 2 is a perspective view of the back side of the main body of the first portion of the arm-like structure of FIG. 1; 2 is a partial longitudinal sectional view of a first portion of the arm-like structure of FIG. 1; FIG. FIG. 2 is a perspective view showing a second portion of the arm-like structure of FIG. 1; FIG. 2 is a front view showing a second portion of the arm-like structure of FIG. 1; FIG. 2 is a cross-sectional view of the main body of the first portion of the arm-like structure of FIG. 1; FIG. 1 is a side view partially showing a robot according to an embodiment of the present disclosure. FIG. 2 is a partial perspective view of a first portion showing a modification of the arm-like structure shown in FIG. 1; FIG. 2 is a partial vertical cross-sectional view of a first portion showing another modification of the arm-like structure of FIG. 1;

An arm-like structure 1 and a robot 100 according to an embodiment of the present disclosure will be described below with reference to the drawings.
As shown in FIG. 1, the arm-shaped structure 1 according to this embodiment is configured by joining a first part 2 and a second part 3, and is, for example, a robot arm.

As shown in FIGS. 2 and 3, the first portion 2 includes a straight and elongated main body portion 4 and a pair of end portions 5 integrally provided at both ends of the main body portion 4. As shown in FIGS. 4 to 6, the main body portion 4 has a substantially uniform wall thickness and a substantially uniform U-shaped cross-sectional shape that opens in one direction, and has a straight gutter-like shape. is formed.

Each end portion 5 includes a flange portion 6 having a shape in which a part of the ring plate is cut out in the circumferential direction, and a hollow hemispherical connecting portion 7 that connects the main body portion 4 and the inner circumference of the flange portion 6. ing. The connecting portion 7 also has approximately the same wall thickness as the main body portion 4.

Each connecting portion 7 is provided with an opening 8 near both ends of the first portion 2, which penetrates the connecting portion 7 in the thickness direction and opens the inside to the outside.
As shown in FIGS. 2 and 3, the plane of each flange portion 6 is arranged parallel to the longitudinal axis of the main body portion 4 and on the same plane as the opening edge of the main body portion 4, and is spaced apart in the circumferential direction. A plurality of (12 in the example shown in FIG. 2) through-holes (second through-holes) 9 are provided that penetrate in the plate thickness direction.
Note that the plane of each flange portion 6 does not necessarily need to be parallel to the longitudinal axis of the main body portion 4, and may be arranged so as to intersect with the longitudinal axis.

The first portion 2 is constructed by press-molding a prepreg made of lightweight and high-strength resin, such as carbon fiber reinforced resin, for example. As shown in FIG. 6, the flange portion 6 is constructed by embedding an arc-shaped metal flat plate (reinforcing member) 20 in a resin, the shape being slightly smaller than the outer diameter of the flange portion 6. A through hole 21 is provided in the metal flat plate 20 at a position that corresponds to the through hole 9 of the flange portion 6.

As a result, the first portion 2 has a straight groove-like recess that is continuous from the connecting portion 7 at one end 5 to the connecting portion 7 at the other end 5 via the main body 4 and is open in one direction. 10.
A plurality of through holes 11 (in the example shown in FIG. 3, 11 on each side) are provided near both end edges of the opening of the main body portion 4 of the first portion 2 at intervals in the longitudinal direction. These through holes 11 are used to fix rivets 18, which will be described later.

The second portion 3 is constructed by, for example, punching out a flat metal plate made of aluminum alloy or the like by press working, and then bending the plate.
As shown in FIGS. 7 and 8, the second portion 3 includes a pair of disk-shaped attachment portions 12 arranged at intervals, and a strip-shaped connection portion 13 that connects these attachment portions 12. It is equipped with

Each attachment portion 12 has an outer diameter dimension that is approximately the same as the outer diameter of the flange portion 6 of the first portion 2 .
As shown in FIG. 8, each mounting portion 12 has a plurality of (12 in the example shown in FIG. 8) through holes (first through holes) 14 that penetrate in the thickness direction near the outer periphery. They are placed at intervals. These through holes 14 are set to positions and sizes that match the through holes 9 of the flange portion 6 of the first portion 2 when the second portion 3 is combined with the first portion 2. Further, each mounting portion 12 is provided with a central hole 15 near the center thereof that penetrates in the thickness direction.

The connecting portion 13 has a width dimension that is approximately the same as the opening width dimension of the recessed portion 10 of the main body portion 4 of the first portion 2 . The connecting portion 13 is provided with a rib-shaped joint portion 16 whose both ends in the width direction are bent at right angles. As shown in FIG. 7, the joint portion 16 is provided with a plurality of through holes 17 (11 on each side in the example shown in FIG. 7) at intervals in the longitudinal direction of the connecting portion 13. These through holes 17 are set at positions and sizes that match the through holes 11 provided in the main body portion 4 of the first portion 2 when the second portion 3 is combined with the first portion 2. By forming the joint portion 16 in a rib shape, the rigidity of the second portion 3 is increased.
Further, in this embodiment, a notch is provided at the boundary between the joint portion 16 and the connecting portion 13 to facilitate bending. However, since this notch may cause foreign matter to enter the inside of the arm-like structure 1, the gap caused by the notch may be filled with putty, a rubber bush, or the like. Thereby, sealing performance can be improved.

As shown in FIGS. 1 and 9, the first part 2 and the second part 3 are constructed by overlapping the flange part 6 on the mounting part 12 in the thickness direction of the mounting part 12, and forming the connecting part of the second part 3. 13 are mutually joined at a position inserted into the inner side of the recess 10 of the main body 4 of the first part 2. For joining, the through hole 17 provided in the joint part 16 and the through hole 11 provided in the main body part 4 are aligned, and as shown in FIG. This is done by inserting the rivet 18 into both the through holes 11 and 17 and caulking it inside the joint 16.

Thereby, the first portion 2 and the second portion 3 are integrally joined by the rivet 18 at the position of the connecting portion 13 of the second portion 3. In the arm-shaped structure 1 according to the present embodiment configured in this manner, the opening of the recess 10 of the first portion 2 is closed by the second portion 3, so that the connection portions 7 at both ends and the main body portion 4 are closed. It has a hollow part 19 continuously formed inside. The hollow portion 19 is open to the outside through an opening 8 provided in the connecting portion 7 of the first portion 2 and a central hole 15 provided in the attachment portion 12 of the second portion 3.

The robot 100 including the arm-like structure 1 according to the present embodiment configured as described above will be described below with reference to the drawings.
The robot 100 according to this embodiment includes at least one arm-like structure 1 described above, as shown in FIG.

For example, as shown in FIG. 10, the arm-like structure 1 is directly fixed to other parts constituting the robot 100, such as a speed reducer 110, at the attachment parts 12 at both ends.
At this time, by passing bolts (see FIG. 11) 30 through the through holes 9 and 14 of the flange portion 6 and the mounting portion 12, which are overlapped in the plate thickness direction, and fastening them to taps (not shown) of the reducer 110, The flange portion 6 and the mounting portion 12 are fastened together with bolts 30. Thereby, the flange portion 6 of the first portion 2 and the attachment portion 12 of the second portion 3 can be firmly fixed together, and the arm-shaped structure 1 can be firmly fixed to the reducer 110 at the same time.

As the reducer 110, a hollow reducer having a through hole 111 in the center is used. As a result, as shown in FIG. 10, the filament 120 such as a cable passed through the through hole 111 of the reducer 110 is inserted into the arm-like structure 1 via the central hole 15 of one of the attachment parts 12. The wiring can be introduced into the hollow part 19 of the other mounting part 12 and taken out from the central hole 15 of the other mounting part 12. When wiring the filamentous body 120, the wiring work can be easily performed by inserting a finger into the hollow portion 19 through the opening 8 provided in the connecting portion 7 of the first portion 2 and handling the filamentous body 120. can.

According to the arm-like structure 1 according to the present embodiment, by assembling the second portion 3 to the elongated first portion 2 having the groove-shaped recess 10 extending in the longitudinal direction and closing the recess 10, both ends can be closed. The structure is closed and has a hollow part 19 inside. Since the recess 10 of the first portion 2 is open in one direction intersecting the longitudinal axis, it is relatively shallow, and a mold for integral molding can be easily created.

Since the first part 2 is manufactured by pressing prepreg made of highly rigid and lightweight carbon fiber reinforced resin, uniform wall thickness can be easily achieved and the highly rigid and lightweight arm-shaped structure 1 can be configured.

In addition, since the metal flat plate 20 is embedded as a metal reinforcing member having a through hole 21 in the flange portion 6 which is compressed by fastening the bolt 30, the flange portion 6 and The attachment portion 12 can be firmly fastened to the reduction gear 110 or the like. Further, the metal flat plate 20 may be one in which a plurality of pipe-shaped metal spacers are embedded.

Further, since the second portion 3 is constituted by a metal flat plate, it can be easily manufactured by punching and bending by press working, and costs can be reduced. Furthermore, it is possible to easily achieve uniform wall thickness and reduce weight. In addition, the two mounting parts 12, which are fixed to separate other parts, are connected by the connecting part 13 and placed on a single part, making it easy to achieve high dimensional accuracy such as relative position and parallelism. can be achieved.

Note that in this embodiment, the second portion 3 is made of a metal flat plate, but it is not limited to this. For example, the material may be made of aluminum die-cast alloy casting, or may be made of resin such as carbon fiber reinforced resin. It may be constructed by insert molding in which metal is embedded with a plurality of taps only in the joint portion 16.
Further, in this embodiment, the first portion 2 may be constructed by injection molding a fiber-reinforced thermoplastic resin.
Further, instead of having a flat plate shape, it may have a shape that includes a recess that forms a hollow portion 19 together with the recess 10 of the first portion 2 .

Further, as shown in FIG. 12, the metal flat plate 20 is formed in an annular shape having a constant thickness, and has a contact surface that directly contacts the mounting portion 12 on one side in the thickness direction and a contact surface on one side in the thickness direction. It may also include an exposed surface exposed around the through hole 9 on at least a portion of the other surface. The exposed surface becomes a seating surface for a bolt passing through the through hole 9. In this case, the washer 31 as shown in FIG. 11 becomes unnecessary.

In this case, the outer circumferential surface of the metal flat plate 20 may be provided with one or more protrusions 22 that protrude in the radial direction at a portion in the circumferential direction. A plurality of protrusions 22 may be provided on the outer peripheral surface of the metal flat plate 20 at intervals in the circumferential direction. Thereby, it is possible to prevent the flat metal plate 20 from coming off and rotating relative to the flange portion 6.
Further, instead of the circular tubular metal flat plate 20, a metal flat plate 20 having a non-circular cross-sectional shape such as a polygonal cylinder may be used. In this case, no protrusion is required.

Furthermore, in the present embodiment, the first part 2 and the second part 3 are joined by the rivet 18, but instead of this, the first part 2 and the second part 3 may be joined by any joining means such as bolts and nuts. Good too. When both the first portion 2 and the second portion 3 are made of resin, an adhesive may be used as the joining means. The rivet 18 and adhesive may be used together.

Further, in this embodiment, a lid member that can be attached to the end portion 5 to open and close the opening 8 may be provided.
Moreover, in this embodiment, as shown in FIG. 11, a stainless steel horseshoe-shaped washer 31 inserted between the bolt 30 and the flange portion 6 may be provided. As a result, when the bolt 30 is passed through the through-holes 9 and 14 and fixed, it is possible to prevent the seating surface of the flange portion 6 around the through-hole 9 from sinking due to the fixation of the bolt 30 with the washer 31, and to prevent the large bolt shaft from collapsing. Since the force can be secured, loosening of the bolt 30 can be prevented.
Furthermore, in this embodiment, at least a portion of the outer circumferential surface of the arm-like structure 1 may be coated with a flame retardant paint.

Regarding the flame-retardant paint, it is preferable that the flame duration is 10 seconds or less even if the paint is placed vertically to the fire and exposed to fire for 10 seconds, and has flame-retardant properties that do not burn more than 127 mm. . More preferably, a test piece ((125 plus or minus 5) x (13 plus or minus 0.5) x t) mm is directly attached to the clamp, and indirect flame is applied twice for 10 seconds with a 20 mm flame, and the burning time of each test piece is is less than 10 seconds, the total burning time of the five pieces is less than 50 seconds, the burning + glow time of each test piece is less than 30 seconds, there is no burning up to the clamp, and there is no burning on the cotton placed below the test piece. Preferably, there is no ignition.

Furthermore, as for the flame-retardant resin material, it is preferable that the flame-retardant resin material has the same performance as the flame-retardant paint.
Furthermore, even if the flame retardant performance of the above-mentioned flame-retardant paint or flame-retardant resin material does not satisfy the conditions described above and is at a somewhat inferior level, the outer part of the arm-like structure 1 may be By coating the surface with the flame retardant paint, the flame resistance of the arm-shaped structure 1 can be improved.

1 Arm-shaped structure 2 First part 3 Second part 6 Flange part 8 Opening part 9 Through hole (second through hole)
10 Recessed portion 12 Mounting portion 13 Connecting portion 14 First through hole 15 Central hole 19 Hollow portion 20 Metal flat plate (reinforcing member)
30 Bolt 31 Washer 100 Robot

Claims (17)

a long first part made of resin and having a groove-shaped recess opening in one direction intersecting the longitudinal direction and an opening opening in the other direction;
a second portion disposed at a position to close the opening of the recess and joined to the first portion;
The second portion includes a pair of attachment portions disposed at both ends in the longitudinal direction, each of which is fixed to another component constituting the robot;
An arm-shaped structure that is attached to the other component in a state in which the first part and the second part are fixed to each other. The arm-shaped structure according to claim 1, wherein the first portion and the second portion are attached to the other component by co-fastening. The arm-shaped structure according to claim 1 or 2, further comprising an elongated hollow portion extending in the longitudinal direction between the first portion and the second portion. The arm-shaped structure according to any one of claims 1 to 3, wherein the second portion is constituted by a metal plate. The second portion includes a strip-shaped connecting portion that connects the pair of the mounting portions arranged at an interval,
The arm-shaped structure according to any one of claims 1 to 4, wherein the first portion and the second portion are joined at the connecting portion. The arm-shaped structure according to any one of claims 1 to 5, wherein a central hole penetrating in the thickness direction is provided at the center of each of the attachment parts. 1 . The second portion includes a plurality of first through holes in each of the attachment portions that penetrate in the thickness direction at intervals in the circumferential direction and allow bolts for fixing to the other parts to pass therethrough. The arm-shaped structure according to claim 6. The first portion includes a pair of flange portions that overlap each attachment portion in the thickness direction near the outer periphery of each attachment portion while being joined to the second portion,
The arm-shaped structure according to claim 7, wherein each of the flange portions includes a plurality of second through-holes formed at positions corresponding to each of the first through-holes. The arm-shaped structure according to claim 8, wherein a metal reinforcing member for reinforcing the second through hole is embedded in the resin constituting the flange portion. The reinforcing member includes a contact surface that contacts the second portion, and an exposed surface in which at least a portion of the surface opposite to the contact surface is exposed around the second through hole. Arm-shaped structure. The first portion includes a pair of flange portions that overlap each attachment portion in the thickness direction near the outer periphery of each attachment portion while being joined to the second portion,
The arm-shaped structure according to claim 3, wherein the opening is provided inside each of the flange portions and opens the hollow portion to the outside. The arm-shaped structure according to any one of claims 1 to 11, wherein the first portion is made of carbon fiber reinforced resin. The arm-shaped structure according to claim 11, further comprising a lid member that can open and close the opening. a bolt insertable into the first through hole;
The arm-shaped structure according to claim 8, further comprising a washer disposed between the bolt and the flange portion when the bolt is inserted into the first through hole. Claim 1: At least a part of the outer circumferential surface is coated with a flame-retardant paint that has a flame duration of 10 seconds or less even when placed vertically and is exposed to fire for 10 seconds, and does not burn beyond 127 mm. The arm-shaped structure according to claim 14. The first part or the second part is made of a flame-retardant resin material that has a flame duration of 10 seconds or less even when placed vertically and is exposed to fire for 10 seconds, and does not burn more than 127 mm. The arm-shaped structure according to any one of claims 1 to 14. A robot comprising a robot arm that is the arm-like structure according to any one of claims 1 to 16.