JPH10202561A - Link structure by composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure sufficient rigidity and attain weight reduction by bonding metallic material and resin material to each other so that a ratio of the volume of a part constituted of metallic material to that constituted of resin material may be larger gradually as a distance from a section constituted of metallic material increases more. SOLUTION: The operating part 25 of a thigh link 14 is formed so that a ratio of the volume of a part constituted of metallic material to that constituted of resin material may increases more as it leaves both revolute joints more. A shifting section where the volume the metallic material and resin material occupy changes gradually is formed between a range the metallic material dominates substantially and a range the resin material dominates substantially. By ensuring bonding force necessary to transmit required driving force between the metallic material and the resin material in the shifting section, it is possible to provide a thigh link 14 as a link structure which owns required rigidity and attains weight reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a link structure constituted by combining materials having different characteristics, and relates to an improvement in technology for making a link structure light and strong.

[0002]

2. Description of the Related Art The technology of constructing a structure by combining materials having different characteristics has already been used in an aircraft where weight reduction is important, but especially in a robot, especially a walking robot, a load applied to a joint portion is important. Since the load is repeatedly applied to the joints at a high frequency, it is not possible to achieve a lightweight structure that can withstand a high repetitive load by only the conventional technology used in the above aircraft.

[0003]

The light weight of a moving body represented by an aircraft or an automobile has a remarkable effect of improving athletic performance and reducing energy consumption due to acceleration / deceleration. However, although a robot is a moving body, it has little time to move at a constant speed, and most of its movement time is added.
Spent on deceleration. Therefore, there is a stronger desire for weight reduction in the case of a robot than in an aircraft or an automobile.
However, in the case of an industrial robot, since the robot itself is fixed to the floor and used, energy consumption can be easily supplied from a fixed power supply via a conducting wire. From a point of view, we cannot afford to spend so much on weight reduction. On the other hand, a walking robot moves with all the energy sources, so it is necessary to reduce the weight even at some cost. In this regard, there is a desire for a lighter weight that is closer to a space rocket carrying all the fuel than an aircraft that uses airborne oxygen as a fuel.
Also, compared to a space rocket, a walking robot has a handicap that requires repeated acceleration and deceleration of its legs forward, backward, left and right even during movement. Further, a walking robot receives a large impact force from the ground every time the leg lands, and this large impact force extremely dislikes a decrease in strength and rigidity due to weight reduction. In addition, walking robots encounter various road surface environments besides flat ground. As a result, an excessive moment is added to a link corresponding to a shin or a peach every step. In addition, the knee joint needs to be designed with a part of the link thin so that the robot can take a squatting posture,
The narrowing of the portion where the transmission torque is large means that it is severe in forming the link with the composite material. Unless a design with sufficient durability is performed under these severe conditions, the composite material is broken apart by the repeated load. In these respects, walking robots are required to design differently from space rockets.

If the walking robot is a bipedal robot,
If the foot does not land at the correct position, the point where the combined force of gravity and inertia force intersects the ground (ZMP: Zero Mom)
ent Point) cannot be secured inside the contact area between the sole and the ground. In the future, control technology will improve dramatically, even if there is a slight deviation in the landing position like a human, move the torso or arm to restore balance, and change the next landing position cleverly and stably The story is different if it comes to restoring gender, but with current technology it will fall. In order to manage the ZMP on the sole of the foot, it is necessary to determine the landing position with high accuracy. For this purpose, the rigidity of the leg link must be sufficiently high and the dimensional accuracy must be extremely high. When the link structure is made of a composite material, it is possible to finish all the required precision parts by machining in the final step, but this will inevitably increase the cost. In order to reduce the number of machining steps in the final process as much as possible, the key point is to minimize errors when assembling with composite materials. It is also required that it can be implemented at low cost. This is a technical issue unique to walking robots, unlike space rockets.

[0005] As a lightweight resin material, a fiber reinforced resin (FRP; Fiber Reinforced Pla) has already been used.
sticks). The greatest feature of this FRP is that it is excellent in rigidity and strength with respect to weight, and the accompanying feature is that it does not rust, but its drawback is that it is weak against local stress. For example, with a screw connection method, a resin screw thread is easily broken and the connection purpose cannot be achieved.

There are two conventional techniques for solving such technical problems, one of which is a technique of connecting two parts using a metal bolt and a matching metal nut. In order to tighten the bolts, it is necessary to use a wrench or the like to prevent the nut from turning.Therefore, space is required to insert the wrench, and both hands are required for assembly. Absent.

Another method is to improve the workability by processing the female screw portion into one of the connecting parts. In this method, only the female screw portion is formed of metal, and this is achieved by press-fitting or assembling the FRP structure with an adhesive or the like. This method uses a metal thread and FR
There is a problem in that the bonding force with P is weak, and peeling occurs under a large repeated load.

A technique capable of coping with a large load with respect to screw connection has been put into practical use by rivet connection, but the rivet connection has the following drawbacks and cannot be used for everything. That is, the appearance after bonding is poor, and post-treatment such as smoothing the surface is required. The principle is that the rivet is mechanically crushed, so when the part located on the back side is in a narrow place where it cannot be accessed, the work becomes very difficult.

As a method intermediate between the rivet method and the screw method, a method is also known in which a metal screw is provided with a flange and the flange is connected to the FRP structure with a rivet. The solution to the problem remains. Therefore, there is a demand for an FPR structure that can withstand a large load applied frequently and that is highly practical.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a link structure made of at least two kinds of materials, a metal material and a resin material, which is suitable as a link for a walking robot, has a macroscopic meaning. The first object of the present invention is to propose a technology for producing a functionally graded material and providing a low-cost, high-quality link structure capable of reducing the weight while securing sufficient rigidity. It is a second object of the present invention to increase the bonding force between a metal material mainly used in a portion where a load is applied and a resin material mainly used in a leveled load.

[0011]

In order to achieve the first object, according to the first aspect of the present invention, as the distance from a portion made of a metal material increases, the metal material can be used. A link structure made of a composite material in which at least two kinds of materials, a metal material and a resin material, are bonded to each other so that the ratio of the volume of the resin material to the volume of the resin material gradually increases. Is configured.

According to such a structure, the transition section in which the volume occupied by the metal material and the resin material gradually changes between the region substantially controlled by the metal material and the region substantially controlled by the resin material. Is provided, and in the transition section, by securing a coupling force necessary for transmitting a required driving force between the metal material and the resin material, the required rigidity is reduced and the weight is reduced. Link structure can be obtained.

[0013] To achieve the second object, the invention according to claim 2 is characterized in that:
A link structure made of a composite material comprising a combination of at least two kinds of materials, a metal material and a resin material, comprising an operating portion connected to the joint portion; The joint body to be delivered and received is formed of a metal material, and at least a part of the operating portion is formed of a resin member made of a resin material. The resin member is bonded to the joint plate portion having a surface area capable of securing an adhesive strength capable of securing a driving force that can be transmitted from the joint body to the resin member. Features.

According to the configuration of the second aspect of the present invention, a metal material is used in a portion where a large load is locally applied, and a resin material is mainly used in a portion where a leveled load is applied. By increasing the joint area between the metal material and the resin material while suppressing an increase in weight, the bonding force between the two can be increased. In other words, the shape that maximizes the surface area when the weight is constant is a plate, and the bonding force due to adhesion is proportional to the contact area. Therefore, to increase the bonding force without increasing the weight, the contact portion only needs to be plate-shaped. Since the resin member is bonded to the joint plate mechanically integrated with the joint main body, the joining force can be increased while suppressing an increase in weight.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, a plate made of a metal material substantially the same as that of the joint main body is mechanically connected to the joint main body. The joining plate portion is constituted by at least a part of the plate, so that a plate formed as a press-formed product of, for example, a rolled material is integrated with a joint main body by a mechanical coupling structure such as welding or brazing. Thus, it is easy to secure the surface area.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the invention, the plate secures the surface area at the bonding portion with the resin member and occupies a volume occupied by the metal material. In order to decrease the ratio of the distance from the joint main body, the width is substantially reduced as the distance from the joint main body increases, so that the driving force between the metal material and the resin material is reduced. Despite the delivery, stress leveling is performed at the joint to prevent damage due to stress concentration and to reduce the weight.

According to a fifth aspect of the present invention, in order to achieve the first object, a joint receiving a driving force mainly composed of a rotational force is provided at at least one end of an operating portion for transmitting the driving force. A link member made of a composite material, which is formed by combining at least two kinds of materials, a metal material and a resin material, wherein the joint body is a component of the joint portion and substantially transfers a driving force. Is formed of a metal material, and the operating portion has an arrangement in which the proportion of the volume occupied by the resin material decreases and the proportion of the volume occupied by the resin material increases with distance from the joint along the path of the driving force, It is characterized in that a metal material and a resin material are bonded.

According to the fifth aspect of the present invention,
Since the volume occupied by the resin material gradually increases along the path of the driving force from the joint where the metal material substantially controls,
A link structure having required rigidity and reduced weight can be obtained.

According to a sixth aspect of the present invention, in addition to the configuration of the second or fifth aspect of the invention, the operating section further comprises:
By providing a connecting plate made of a metal material for connecting the plurality of joint bodies to each other, the plurality of joint bodies made of a metal material can be connected via a metal connecting plate. By simplifying logistics management and improving the dimensional accuracy between multiple joint bodies, the number of man-hours in the final process can be reduced, especially when there are many joint bodies and the final assembly shape is complicated. This is effective when there are places where machining in the final step becomes extremely difficult.

According to the seventh aspect of the present invention, in addition to the configuration of the sixth aspect of the present invention, the connecting plate has a flat plate shape in a plane substantially perpendicular to the axis of the torque acting on the joint. By being formed, it is possible to realize a structure capable of transmitting torque by preventing the connecting plate from buckling due to a bending moment while reducing the weight.

According to an eighth aspect of the present invention, in addition to the configuration of the sixth aspect of the invention, the connecting plate is formed so as to correspond to an outline of an operating portion connecting a plurality of joint bodies. Since the resin member made of the resin material is bonded to the connection plate, the connection plate is formed so as to have the contour of the shape of the link structure at the time of completion. When a fiber reinforced resin used as a resin material is bonded to the connecting plate, a simple molding die is required.

According to the ninth aspect of the present invention, in addition to the configuration of the seventh aspect of the present invention, a resin material generated by firing after bonding the resin member made of the resin material to the connecting plate. In addition, the resin members made of the resin material are bonded to both the front and back surfaces of the connecting plate so that the thermal strains caused by the difference in thermal expansion of the metal material and the thermal expansion due to the thermal expansion difference of the metal material are mutually canceled, so that the deformation due to the heat distortion at the time of firing. In addition to the force acting on the front and back of the metal connecting plate in the same direction to suppress distortion, the area where the surface of the metal material and the surface of the resin material contact is doubled,
The bonding force can be increased.

According to a tenth aspect of the present invention, in addition to the configuration of the fifth aspect of the present invention, at least one prepreg made of a fiber reinforced resin in which the orientation directions of the reinforcing fibers are set to two directions intersecting each other. The layer is disposed on the operating portion such that the two directions intersect the axis of the torque acting on the joint at substantially the same angle, and according to the invention of claim 11, the layer is arranged on the actuation portion. In addition to the above configuration, a prepreg made of a fiber reinforced resin having an orientation direction of a reinforcing fiber defined in a circumferential direction of a substantially cylindrical surface having an axis parallel to an axis of a torque acting on the joint portion and connected to the operating portion Since at least one layer is provided around the joint main body, torque acting on the joint is applied to the reinforcing fibers as tension, and the torque is effectively transmitted with a small number of prepreg layers. Rukoto can.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.
The illustrated specific example takes a leg structure of a bipedal walking robot as an optimal embodiment, and illustrates a link corresponding to a human peach among them.

FIGS. 1 to 7 show a first embodiment of the present invention. FIG. 1 is a skeleton diagram of a leg of a walking robot viewed from an oblique rear side, and FIG. 2 is a leg of the peach link of FIG. FIG. 3 is a view of the peach link of FIG. 1 from the inside of the leg, FIG. 4 is a sectional view taken along line 4-4 of FIG. 2, FIG. 5 is an enlarged view of the lower part of FIG. 6 is a sectional view taken along line 6-6 in FIG. 4, and FIG. 7 is a view showing the volume distribution of the metal material and the resin material in the direction along the longitudinal direction of the peach link.

First, referring to FIG.
Are connected to left and right legs L, L via vertical axes 12, 12, respectively. Both legs L, L are connected to an upper cross joint 13 connected to the vertical axis 12 and an upper cross joint 1
A peach link 14 connected to the lower portion of the peach link 3; a snare link 16 connected to the lower end of the peach link 14 with a degree of freedom in the front-rear direction with a degree of freedom about a horizontal axis 15 extending in the left and right directions; It is constituted by a foot 18 connected to the lower end of the snake link 16 via a lower cross joint 17. The upper cross joint 13 includes a horizontal axis 19 extending in the front-rear direction and a horizontal axis 20 extending in the left-right direction in an arrangement in which the axes 19 and 20 are orthogonal to each other. Is connected to the waist 11 with a degree of freedom about the vertical axis, a degree of freedom in the left-right direction, and a degree of freedom in the front-rear direction. Snelink 1
Reference numeral 6 is connected to the peach link 14 with a degree of freedom around the axis of the horizontal shaft 15, that is, a degree of freedom in the front-rear direction. Further, the lower cross joint 17 includes a horizontal axis 21 extending in the left-right direction and a horizontal axis 22 extending in the front-rear direction, with the horizontal axes 21 and 22 being orthogonal to each other. Are connected to the lower end of the snelink 16 with a degree of freedom in the front-rear direction and a degree of freedom in the left-right direction.

A walking robot having such a configuration is disclosed in many of the specifications (for example, Japanese Patent Application Laid-Open No.
84782), which requires further explanation.

Referring to FIG. 2, FIG. 3 and FIG.
The peach link 14 as a link structure of the present invention includes a first joint 23 at an upper end thereof, a second joint 24 at a lower end thereof, and an operating portion 25 connecting the two joints 23 and 24. It is.

The first joint 23 is formed by connecting an outer yoke 26 and an inner yoke 27 arranged coaxially with the outer yoke 26 by a connecting portion 28 connecting the lower portions of the yokes 26 and 27. The upper cross joint 13 shown in FIG. 1 is configured to receive a motor and a speed reducer (not shown) for realizing the degree of freedom around the horizontal axis 20, that is, the degree of freedom in the front-rear direction.

The outer yoke 26 is attached to an outer sleeve 29 made of a metal such as an aluminum alloy.
The inner yoke 27 is formed by mechanically connecting a bowl-shaped outer cup 30 made of the same metal material as the inner sleeve 31 to an inner sleeve 31 made of a metal such as an aluminum alloy. Is mechanically coupled to a bowl-shaped inner cup 32 made of

A connecting flange portion 29a extending outward is integrally provided at an axially intermediate portion of the outer sleeve 29, and an outer side of the outer sleeve 29 is provided at one axial end (right side in FIG. 4). A flange portion 29b extending toward the front is integrally provided. The other side in the axial direction of the inner sleeve 31 (the left side in FIG. 4).
A connecting flange 31a extending outward is integrally provided at the end. The outer cup 30 is connected to the outer surface of the other end in the axial direction of the outer sleeve 29 and the connecting flange 29a by a known mechanical connection structure such as welding or brazing, and the inner cup 32 is connected to the outer cup 29 by welding or brazing. The inner sleeve 31 is connected to the outer surface of one end in the axial direction and the connecting flange 31a by a known mechanical connection structure. Thus, the two sleeves 29, 31 before assembly are formed so as to have waste on their inner surfaces, and the two sleeves 29, 31 are attached to the jig by the connecting portion 28 in a state of being assembled to the jig. After connection and assembly are completed, the inner surfaces of the two sleeves 29, 31 are machined to ensure the required mechanical accuracy with the two sleeves 29, 31 concentric.

The output of the motor housed in the first joint 23 is enlarged by the speed reducer and connected to the flange 29b of the outer sleeve 29. Further, the driving force is transmitted from the connecting flange 29a of the outer sleeve 29 to the operating part 25. Is transmitted, and the driving force is substantially transferred between the outer sleeve 29 and the operating portion 25. That is, the outer yoke 26 functions as a joint body that substantially transfers the driving force. on the other hand,
The inner yoke 27 has a structure in which the bearings supporting the motor and the speed reducer are simply housed, and the rotational torque is not transmitted.

The flange portion 29b is assembled with a little waste in consideration of the distortion when baking in combination with CFRP as a resin material, which is the main constituent material of the operating portion 25, and is assembled after baking. It is finished to the required accuracy by being cut off by machining. In the flange portion 29b, a plurality of screw holes 33 for fastening members for transmitting the driving force from the speed reducer are provided at intervals in the circumferential direction.

Referring also to FIG. 5, the second joint 24
Is composed of an outer yoke 34 and an inner yoke 35 arranged coaxially with the outer yoke 34.
Are connected by a connecting portion 36 connecting the lower portion of the horizontal shaft 15 to the snelink 16 shown in FIG. Is done.

The outer yoke 34 is attached to an outer sleeve 37 made of a metal such as an aluminum alloy.
The inner yoke 35 is formed by mechanically connecting a bowl-shaped outer cup 38 made of the same metal material as the inner sleeve 39 to an inner sleeve 39 made of a metal such as an aluminum alloy. Is mechanically connected to a bowl-shaped inner cup 40 made of

A connecting flange 37a extending outward is integrally provided at an axially intermediate portion of the outer sleeve 37, and a flange 37b connected to the connecting flange 37a is formed at one axial end of the outer sleeve 37. It is formed integrally with the outer sleeve 37 so as to be thick. In addition, a connection flange portion 39a that protrudes outward is integrally provided at the other end of the inner sleeve 39 in the axial direction (the side opposite to the outer sleeve 37). The outer cup 38 is connected to the inner sleeve 3 of the outer sleeve 37 by a known mechanical coupling structure such as welding or brazing.
The inner cup 40 is connected to one end of the inner sleeve 39 in the axial direction (opposite to the outer sleeve 37) by a known mechanical connection structure such as welding or brazing. ) At the end outer surface. Thus, the two sleeves 37, 39 before assembly are formed so as to have waste on the inner surface side thereof, and are connected by the connecting portion 36 in a state where the two sleeves 37, 39 are assembled to the jig. After being connected and the assembly is completed, both sleeves 29,
The two sleeves 37, 31 are concentric with each other, and the parallelism and the distance between the axes of the first and second sleeves 29, 31 at the first joint 23 are designed values to ensure the required mechanical accuracy. The inner surface of 39 is machined.

The motor 42 for driving the snake link 16 with respect to the peach link 14 is, as shown in FIG.
The output of the motor 42 is transmitted to a speed reducer 41 assembled in the second joint portion 24 by a belt 43 shown by a virtual line, and the torque is amplified to provide a snelink. 16 to accelerate and decelerate the slink 16 in the front-rear direction. The reaction force that has driven the snelink 16 must be borne by the peach link 14, so the flange 3
7b are provided with a plurality of screw holes 44, and the reduction gear 41 is fastened to the flange portion 37b by the screw holes 44. That is, the outer yoke 34 functions as a joint body that substantially transfers the driving force, and the inner yoke 35 does not transmit the rotational torque.

The flange portion 37b is formed so as to have some cutting allowance in consideration of distortion when combined with CFRP and firing, and is cut to a design value after firing. Since a very large torque is applied to the screw holes 44 of the flange portion 37b when moving up and down the stairs, the second joint 2
The strength and stiffness of No. 4 are designed on the basis of this torque, and the large torque acts on the entire peach link 14.

The lower portion of the operating portion 25 connecting the first and second joint portions 23 and 24 is thinner than the upper portion of the operating portion 25 in order to secure a large rotation angle while avoiding interference with the snelink 16. It is well understood that such a shape is not suitable for transmitting the transmission torque under low stress.

The operating portion 25 is basically made of CFRP as a resin material. However, in order to determine the positional relationship between the first and second joints 23 and 24, an aluminum alloy or the like is used. A pair of connecting plates 4 made of a metal material
5, 46, and one connecting plate 45 is connected to the connecting flange 29 of the outer sleeve 29 of the first joint 23.
a and a connecting flange 37 a of the outer sleeve 37 of the second joint 24 by a mechanical connection structure such as welding or brazing, and the other connecting plate 46 is connected to the first joint 2.
3, a connecting flange 31a of the inner sleeve 31 of the second
Connecting collar 39a on inner sleeve 39 of joint 24
At the same time by a mechanical connection structure such as welding or brazing. That is, one connecting plate 45 is formed in a flat plate shape in a plane substantially orthogonal to the axis of the torque acting on the first and second joints 23 and 24, and the first and second joints 2.
3 and 24, and both connecting plates 45 and 46 are connected.
Are formed in a shape corresponding to the outline of the operating portion 25.

The connecting plate 45 has a peripheral portion,
It has a substantially L-shaped cross-sectional shape at an opening 47 provided in the connecting plate 45 for accommodating the motor 42, and provides a resistance to bending. This L-shaped cross section, when hardened by CFRP as described below,
The section modulus of P is dramatically increased, and the rigidity of the entire peach link 14 is extremely increased. The connecting plate 45 has screw members 48 having screw holes for mounting the motor 42 and screw holes 49 around the connecting plate 45 for mounting a belt cover (not shown) to be processed. A small piece (not shown) or the like is connected in advance by a mechanical connection structure such as welding or brazing. The screw members 48 are connected to the connecting plate 4 in order to avoid distortion when the CFRP is bonded and fired.
5, and are machined after firing so that the surfaces of the screw members 48 are aligned.
In addition, the height of the second joint portion 24 with respect to the flange 37b is suppressed to a design value, and the belt alignment is optimized.

In addition to the above, holes 50 for receiving electric wires for transmitting information and energy from the upper body of the robot to the lower link, and fixing holes for harnesses in which the electric wires are bundled are provided in the connecting plate 45. The screw holes 51, etc. are processed in advance. Further, from the viewpoint of weight reduction, the connecting plate 45 is provided with lightening holes 52, 53 and the like everywhere. These lightening holes 52, 53, etc. contribute to weight reduction as well as prepregs attached to the front and back of the connecting plate 45.
2, 53, etc., so that they are firmly adhered to each other to further enhance the strength at the time of completion.

The other connecting plate 46 is also connected to the connecting plate 4.
As in FIG. 5, as shown in FIG. 4, the peripheral portion is bent into an L-shape to increase the strength and rigidity, a lightening hole 54 is provided, and a hole 55 for passing an electric wire is provided as necessary. Provided.

As shown in FIGS. 3 and 5, sleeves 37 and 39 and cups 3 are provided inside the outer yoke 34 and the inner yoke 35 in the second joint 24.
The connection plate portions 56 and 57 formed by bending a metal plate made of the same metal material as the metal plates 8 and 40 are connected by a mechanical connection structure such as welding or brazing.

The ends of the connecting plates 45, 46 on the side of the second joint 24 function as joining plates 45a, 46a. These joining plates 45a, 46a and the joining plates 56, 57 are used. As shown in detail in FIG. 5, the connecting flange portions 37a, 39a at the connecting portions to the respective sleeves 37, 39 are formed so as to gradually reduce the thickness of the joining plate portions 45a, 46a. , Sleeve 37
From the viewpoint of the transmission of torque from the shaft to the operating portion 25, the thickness of the metal portion gradually tapers away from the center of the second joint portion 24.

The operating portion 25 is made of CFRP as a resin member.
Is formed in a tubular shape having a rectangular cross section. In the connecting plates 45 and 46, two prepreg layers 58 and 59 made of CFRP are connected as shown in FIG. The plates 45 and 46 are bonded to the connecting plates 45 and 46 so as to sandwich the plates 45 and 46 in a sandwich shape.
The prepreg layers 58, 59 are adhered to each other between the side edges 5, 5,. In FIG. 5 and FIG. 6 referred to in the following description, only the thickness of the CFRP is exaggerated for better understanding of the gist of the invention.

At the bonding portion of each prepreg layer 58, 59 to the outer yoke 34, the prepreg layer 5
8 and 59 are bonded to the joining plate portions 45a, 46a, 56 and 57 which are mechanically connected to the outer yoke 34. From the sleeve 37, the joining plate portions 45a, 46a and 5 are attached.
The plate thickness of the metal portion gradually tapers toward the 6,57 side. That is, when the CFRP is coupled to the sleeve 37, the ratio of the metal is set to be higher at the center of the sleeve 37, and the ratio of the CFRP is set to be higher as the distance from the center of the sleeve 37 increases.
Although the thickness of the illustrated metal shape changes stepwise, it is needless to say that it is more preferable to change the thickness continuously for a larger load.

Each prepreg layer 58, 59 may be a single prepreg, but is usually formed by laminating a plurality of prepregs having different fiber directions. Incidentally, the torque at the second joint portion 24 is transmitted from the fastening portion of the reduction gear 41 to the flange portion 37b to the outer sleeve 37, and is mechanically connected to the outer sleeve 37 at a location indicated by a dotted line 60 in FIG. Due to the structure, a large part of the torque is transmitted to the connecting plate 45. The strength of this historical mechanical coupling structure has been sufficiently elucidated, and quality control is easy to perform. It is the magnitude of the torque to be transmitted and the thickness of the connecting plate 45 that determine the position of the dotted line 60 that is the welding line, and the calculated stress in this portion is equal to or smaller than the design reference value.
The radius of the dotted line is determined.

In the case of the prepreg of CFRP, the direction of the fibers to be woven is usually aligned, and in this embodiment, a load is applied from the outer sleeve 37 to the operating portion 25 in the form of a rotational force (torque). 58, 59 include at least one prepreg woven, for example, oriented in mutually orthogonal directions, wherein the fibers of the prepreg are 6 in FIG.
The two directions are oriented so as to intersect the direction indicated by 1, that is, the axis of the torque acting on the second joint 24 at substantially the same angle. Due to this orientation, the torque is borne in the form of fiber tension, so that a large number of layers can transmit a large torque.

The prepreg layers 58 and 59 are bent around the connecting plate 45 in accordance with the shape of the connecting plate 45.
As shown in FIG. 3, it is formed so as to constitute the side wall of the operating portion 25. For this purpose, a decomposable male mold made of gypsum or the like is installed inside the peach link 14, and the prepreg layers 58, 59 are adhered along the male mold. Molding /
After firing, the male mold is disassembled from the opening 47 of the connecting plate 45 and removed to the outside, and the cavities required inside the peach link 14, such as a space for receiving a motor and a space for storing electric wires and couplers thereof, are provided with the male mold. Reserved as the space occupied by the mold. In this case, securing an unnecessary space increases the cost of manufacturing by complicating the male mold, so that it is possible to fill the inside with a honeycomb structure or a lightweight material such as styrene foam as is known. The honeycomb structure 62 is also shown in the present embodiment. That is, on the inside of the connecting plate 45, a honeycomb structure 62 having a thickness corresponding to the bending height of the plate 45 is provided.
The cells are arranged with the cells facing as shown in FIG. There is another reason for using the honeycomb structure 62. Since the screw members 48 are connected to the connecting plate 45 as described above, the screw members 48 project from the connecting plate 45 inward. If the gap between the male mold and the prepreg layer 59 is not filled by the honeycomb structure 62, it becomes extremely difficult to remove the gypsum mold after firing, and the thickness of the honeycomb structure 62 is A dimension equal to or slightly larger than the length of the screw members 48 is selected to facilitate removal of the mold after firing. The honeycomb structure 63 is also provided in a space surrounded by the outer cup 38 and the joining plate portion 56, so that it is not necessary to make the plaster mold an unnecessarily complicated shape. The same is true for the connecting plate 46 on the opposite side. Here, the honeycomb structure 64 is filled over a considerably wide area,
This contributes to making the plaster mold a simple shape. Needless to say, these honeycomb structures 62, 63, 64 also have a role of increasing the rigidity of the formed link. Further, a prepreg layer 67 may be attached to the inner surface side of each of the honeycomb structures 62 to 64.

The prepreg layers 65, 66 connected to the prepreg layers 58, 59 wrap around the outer surfaces of the outer cup 38 and the inner cup 40, and a part of the torque transmitted to the outer sleeve 37 is transmitted to the operating portion 25. Has been communicated. Of the two prepreg layers 65 and 66, the prepreg layer 6
5 preferably comprises three layers, and at least one of the three layers is provided with carbon fibers along the circumferential direction of the outer cup 38 (direction indicated by 67 in FIG. 5) so as to be optimal for transmitting torque. It is oriented up to the side surface of the working part 25. A part of the torque transmitted to the outer sleeve 37 due to the presence of the prepreg layer 65 is transmitted to the outer cup 38, and is transmitted to the prepreg layer 65 by the adhesive force from the cup 38, but the torque is effectively transmitted to the fiber as tension. Thus, a large torque can be transmitted with a small number of prepreg layers 65. On the other hand, the prepreg layer 66 stretched on the surface of the inner cup 40 does not need to determine the fiber direction for the purpose of torque transmission because the inner sleeve 39 does not contribute to torque transmission in this embodiment. Further, the CFRP is formed so as to wrap around the combined body of the outer cup 38 and the outer sleeve 37 in order to more reliably transmit the force from the outer sleeve 37 to the operating portion 25.

The connecting portion 36 connecting the outer yoke 34 and the inner yoke 35 in the second joint 24 is
It is formed of a prepreg connected to the prepreg layers 58 and 59 of the operation section 25. Such a connection structure between the second joint portion 24 and the operation portion 25 is applied to a connection portion between the first joint portion 23 and the operation portion 25. Is omitted.

Referring to FIG. 6 as well, a hole 68 for guiding the electric wire once received in the peach link 14 to the snelink 17 side is provided on the inner side of the one connecting plate 45 to a somewhat thicker. Is provided on the metal plate 69.
Reference numeral 9 is connected to a metal attachment plate 70 by welding or brazing. Moreover, screw holes 71 for fixing electric wires are formed in the metal plate 69. The two sides of the prepreg layer 7 are adhered to the joining plate portions 56 and 57 so as to be continuous with the prepreg layers 58 and 59, respectively.
It is sandwiched between 2,73.

By the way, there is no external force applied to the metal plate 69 except for applying an external force when the electric wire is attached. Therefore, the screw holes 71 are small and the number of screw holes 71 is small. In addition, the surface area of the attachment plate 70 may be small in this sense, but the attachment plate 70 is elongated as shown in the drawing to make the CFRP plate rigid.
On both sides, the CFRP layers are fired away from each other to increase the section modulus of this portion after firing. Further, the holes 68 and the screw holes 71 are located at a deep position where it is difficult to work after the whole is assembled, but before the assembly, the machining of these holes 68, 71. Pasted and fired.

In such a peach link 14, the outer yoke 2 which is a component of the first and second joints 23 and 24 at both ends of the operating portion 25 and substantially transfers the driving force is provided.
6 and 34 are formed of a metal material, and the operating portion 25 is formed of CFRP.
Prepreg layers 58 and 59 as a resin member made of
As shown in FIG. 7, the operating portion 25 moves away from the joints 23 and 24 with respect to the volume of the portion made of a metal material.
It is formed such that the volume ratio of the portion made of the resin material gradually increases. Accordingly, a transition section where the volume occupied by the metal material and the resin material gradually changes is provided between the region where the metal material substantially controls and the region where the resin material substantially controls, and the transition section is provided. In the section, the peach link 14 as a link structure having a required rigidity and a reduced weight is obtained by securing a coupling force necessary for transmitting a required driving force between the metal material and the resin material. Can be obtained.

Moreover, in securing the above-mentioned coupling force,
The joining plates 45a, 56 made of a metal material and provided on the outer yokes 26, 34 in a mechanically integrated structure are connected to the outer yokes 2
6, 34 and the prepreg layers 58, 59 are formed so as to have a surface area capable of securing an adhesive strength capable of transmitting a driving force between the prepreg layers 58, 59, and the prepreg layers 58, 59 are adhered to their joining plate portions 45a, 56. You. Therefore, it is possible to mainly use a resin material in a portion where a leveled load is applied, and it is possible to increase a bonding area between the metal material and the resin material by increasing a bonding area of the resin material while suppressing an increase in weight. Becomes That is, the shape that maximizes the surface area when the weight is constant is a flat plate, and the bonding force by adhesion is proportional to the contact area, so if the contact portion is plate-shaped to increase the bonding force without increasing the weight, Well, outer yoke 26,
By bonding the prepreg layers 58, 59 to the joining plate portions 45a, 56 mechanically integrated with the, the bonding force can be increased while suppressing an increase in weight. As a result, a large driving force from the joints 23 and 24 can be reliably transmitted to the prepreg layers 58 and 59, and it is possible to cope with the design of a walking robot having a wide range of dead weight and payload.

The joining plate portion 45a forms a part of the operating portion 25 and is a portion of the connecting plate 45 mechanically connected to the outer yokes 26 and 34. The connecting plate 45 is made of, for example, a rolled material. By using a press-formed product, it is easy to secure the contact area.

Further, the connecting plate 4 forming the joining plate portion 45a
Numeral 5 is formed such that the width is substantially reduced as the distance from the outer yoke 34 increases due to the presence of the hole 53, and the driving force is transferred between the metal material and the resin material. In spite of this, it is possible to prevent the breakage due to the occurrence of stress concentration by leveling the stress at the joint, and to reduce the weight.

The connecting plate 45, which constitutes a part of the operating portion 25,
Since 46 connects the outer yokes 26 and 34, the outer yokes 26 and 3 are formed before the peach link 14 is formed.
4 can be connected in advance, so that the physical distribution management in the manufacturing process can be simplified, and the manufacturing process for molding and firing the CFRP portion can be simplified. In addition, by increasing the dimensional accuracy between the outer yokes 26 and 34, it is possible to make use of the dimensions beforehand processing at locations other than those requiring extremely high dimensional accuracy after molding and firing. This is particularly effective when the final assembly shape is complicated and there is a portion where machining in the final step becomes extremely difficult as in the present embodiment.

The shape of the connecting plates 45 and 46 can be freely designed, and various accessories such as a motor 42, an encoder (not shown), wiring, and a coupler are housed in the peach link 14. Suitable for the design of "skeleton" robots.

Further, the connecting plates 45, 46 are formed in a flat plate shape in a plane substantially perpendicular to the axis of the torque acting on the first and second joints 23, 24, so that the weight can be reduced. The connecting plate 45,
A structure capable of transmitting torque by preventing the buckling of the buckle 46 can be realized.

In addition, connecting plates 45 and 46 are formed corresponding to the outline of the operating portion 25 and the prepreg layer 5
Since the bonding plates 8 and 59 are bonded to the connecting plates 45 and 45, the operation for bonding the prepreg layers 58 and 59 is facilitated, and the molding die can be simplified.

Further, prepreg layers 58 and 59 are adhered to both the front and back surfaces of the connecting plates 45 and 46, and the difference in thermal expansion between the resin material and the metal material caused by the firing after the prepreg layers 58 and 59 are adhered. The accompanying thermal strains are mutually cancelled, and the deformation force due to the thermal strain during firing acts on the front and back surfaces of the metal connecting plates 45 and 46 in the same direction to suppress the strain, and further, the metal material The area of contact between the surface of the resin material and the surface of the resin material can be doubled to increase the bonding force.

In this way, the prepreg layers 58 and 59 made of CFRP, which is the main constituent material of the operating portion 25, are bonded to the first and second joint portions 23 and 24 to form the peach link 14. The bonding structure by such bonding can obtain a smooth surface without post-treatment, can have an excellent appearance, and can be bonded by firing with a mold, so that even a complicated shape can be obtained. It is possible to combine without requiring troublesome work.

Since the prepreg layers 58 and 59 are made of CFRP having high strength, they can be designed to be thin. However, due to this characteristic, there may be a case where the rigidity is rather concerned. For example, a substantially flat structure having a large area has sufficient strength, but a portion with low rigidity is produced. When an unexpected load is applied to this low-rigidity part, there is a risk of buckling failure. In order to eliminate this drawback, it is effective to make an appropriate brace on the plane. In the state where the brace is put, this brace and the thin CFR are as if
The skin of P emphasizes and strengthens the whole. Achieving this brace by simply increasing the thickness of the FRP will increase manufacturing costs, such as the necessity of special jigs and molds to accurately set the shape and position of the brace. However, one of the connecting plates 45 in the operating portion 25 is
The peripheral portion and the opening 47 have an L-shaped cross-sectional shape, and the other connecting plate 46 has its peripheral portion bent into an L-shape. By sintering the prepreg layers 58 and 59 away from each other at the brace portions, the section modulus of the prepreg layers 58 and 59 can be increased and the rigidity can be increased. Both prepreg layers 58, 5
The shape and installation position of the brace from which 9 has been separated can be determined more reliably and inexpensively.

FIG. 8 shows a second embodiment of the present invention, in which a lightening hole 53 ′ provided in the operating portion 25 on the side of the second joint portion 24 of the connecting plate 45 is separated from the second joint portion 24. As the width increases, it is formed in a triangular shape. In this manner, when the composition of the metal material and CFRP is overviewed according to the distance from the center of the second joint 24, the metal material occupied by 100% at the center of the second joint 24 is from the center. Gradually CF
The ratio of RP increases, and to realize this shape, it is only necessary to make the shape of the die for pressing the connecting plate 45 into such a shape, and there is no increase in cost.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in the above-described embodiment, the case where CFRP is selected as the resin material and aluminum alloy is selected as the metal material is described. However, the application of the concept of the present invention is not limited to this, and it is necessary to reduce the weight. Needless to say, the present invention can be applied to all composite material structures whose main purpose is to transmit force. That is, besides aluminum alloys, it is possible to select iron-based metals, titanium alloys, magnesium alloys, and the like as metal materials. In addition to CFRP, glass fiber reinforced resins or short fiber reinforced resins are used as resin materials. It is also possible to select.

Further, in the disclosure of the present invention, a link of a bipedal walking robot has been described as an example, but the gist of the present invention is to propose a technique for configuring a link structure to be lightweight and highly rigid. It goes without saying that the present invention can be applied to a link structure in a body or a link structure of an industrial robot.

[0070]

As described above, according to the first aspect of the present invention, the point of application of the local force is substantially made of metal, and the local point of application of the force is easily applied to the resin material in accordance with the distance away from the point of application. As a result, a link structure having a light weight and high rigidity as a whole can be provided at a low cost and in a high quality form.

According to the second aspect of the present invention, when the resin material receives a torque mainly acting on the joint made of a metal material, the joint area between the metal material and the resin material is increased while suppressing an increase in weight. As a result, the coupling force between the two can be increased while suppressing the increase in weight, and the relatively large driving force from the joint can be reliably transmitted to the resin material, making it possible to design a wide range of walking robots with their own weight and payload. In addition, it is possible to design a robot that can support a wide range of payload even when applied to an industrial robot.

According to the third aspect of the present invention, a plate formed as a press-formed product of a rolled material, for example, is integrated with the joint main body by a mechanical connection structure such as welding or brazing, so that a sufficient connection is achieved. Not only is it easy to secure the surface area required to obtain the force, but also the selection of the joining place and the expansion of the area are free, and even when applied to an industrial robot, a robot capable of handling a wide range of payloads can be designed.

According to the fourth aspect of the present invention, even though the driving force is transferred between the metal material and the resin material, the stress is leveled at the joint so that the damage due to the occurrence of stress concentration is prevented. It is also possible to prevent the occurrence and to reduce the weight.

According to the fifth aspect of the present invention, the volume occupied by the resin material gradually increases along the path of the driving force from the joint where the metal material substantially controls, so that it has the necessary rigidity. Thus, a link structure having a reduced weight can be obtained.

According to the sixth aspect of the present invention, a plurality of joint bodies made of a metal material can be connected via a metal connecting plate, which simplifies distribution management in the manufacturing process, By increasing the dimensional accuracy between the joint bodies, it is possible to reduce the number of man-hours in the final process, and since the shape of the connecting plate can be freely designed, various accessories such as motors, encoders, wiring,
It is possible to easily design a so-called “exoskeleton” robot containing couplers and the like.

According to the seventh aspect of the present invention, it is possible to realize a structure capable of transmitting torque by preventing the connecting plate from buckling due to bending moment while reducing the weight of the operating portion.

According to the eighth aspect of the present invention, in addition to the configuration of the sixth aspect of the present invention, the connecting plate is formed so as to have the contour of the shape of the link structure at the time of completion. The operation for bonding the resin material is facilitated, and a simple molding die is required for bonding the fiber reinforced resin used as the resin material to the connecting plate.

According to the ninth aspect of the present invention, the deformation force due to the thermal distortion during firing acts on the front and back of the metal connecting plate in the same direction, thereby suppressing the distortion. The area of contact with the surface can be doubled to increase the bonding force.

According to the tenth and eleventh aspects of the present invention, the torque acting on the joint is applied to the reinforcing fibers as tension, and the torque can be transmitted effectively with a small number of prepreg layers. It is possible to reduce the manufacturing cost while helping to reduce the weight.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a leg of a walking robot viewed from an obliquely rear side.

FIG. 2 is a view of the peach link of FIG. 1 as viewed from the outside of a leg.

FIG. 3 is a view of the peach link in FIG. 1 as viewed from the inside of a leg.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a lower enlarged view of FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a diagram showing a volume distribution of a metal material and a resin material in a direction along a longitudinal direction of the peach link.

FIG. 8 is a view corresponding to FIG. 2 of a second embodiment.

[Explanation of symbols]

 14: Momolink 23, 24 as a link structure 23, 24 ... Joint 25 ... Actuator 26, 34 ... Outer yoke as a joint main body 45 ... Connecting plate 45a, 56 ... Joining Plate portions 58, 59: prepreg layer as resin member 65: prepreg layer

Claims (11)

[Claims] According to the present invention, the ratio of the volume of a portion made of a resin material to the volume of a portion made of a metal material gradually increases as the distance from a portion made of a metal material increases. A link structure made of a composite material, wherein at least two kinds of materials, a metal material and a resin material, are bonded to each other. 2. A joint (23, 2) to which a rotational motion is transmitted.
4) and an operating part (2) connected to the joints (23, 24).
5) wherein at least two of a metal material and a resin material are provided.
In a link structure made of a composite material formed by combining different kinds of materials, a joint body (2) which is a component of the joints (23, 24) and substantially delivers and receives a driving force.
6, 34) is formed of a metal material, and said working portion (25)
A resin member (58,
59), a joining plate portion (45a, 56) made of a metal material and formed substantially in a plate shape is provided on the joint main bodies (26, 34) in a mechanically integrated structure. 2
6, 34) on the joining plate portions (45a, 56) having a surface area capable of ensuring an adhesive strength capable of transmitting a driving force from the resin members (58, 59) to the resin members (58, 59).
9) A link structure made of a composite material, wherein the link structure is bonded. 3. A plate (45, 56) made of substantially the same kind of metal material as the joint body (26, 34) is mechanically connected to the joint body (26, 34). , 5
6) At least a part of the joining plate portion (45a, 56)
The link structure made of a composite material according to claim 2, wherein: The plate (45) is provided with the resin member (5).
8, 59) at the joint with the joint body (26, 59).
4. The method according to claim 3, wherein the width is substantially reduced as the distance from the joint main body increases, so as to decrease as the distance from the joint increases. Link structure made of composite material. 5. A joint member (23, 24) for receiving a driving force mainly composed of a rotational force is provided at at least one end of an operating portion (25) for transmitting the driving force, and a metal material and a resin material are provided. In a link structure made of a composite material, which is formed by combining at least two kinds of materials, the joint bodies (26, 34) which are components of the joints (23, 24) and substantially transfer a driving force. ) Is formed of a metal material, and the operating portion (25) decreases in the volume ratio occupied by the metal material and occupies the resin material as the distance from the joint portion (23, 24) increases along the path of the driving force. A link structure made of a composite material, wherein a metal material and a resin material are bonded in an arrangement in which a volume ratio increases. 6. The operating part (25) includes a connecting plate (45) made of a metallic material for connecting a plurality of the joint main bodies (26, 34) to each other. A link structure made of the composite material described. 7. The joint plate (45) is connected to the joint part (2).
The link structure made of a composite material according to claim 6, wherein the link structure is formed in a flat plate shape in a plane substantially orthogonal to an axis of torque acting on (3, 24). 8. A resin member made of the resin material, wherein the connection plate is formed corresponding to an outline of an operating portion connecting the plurality of joint bodies.
A composite link structure according to claim 6, characterized in that (59) is glued to the connecting plate (45). 9. Thermal distortion caused by a difference in thermal expansion between a resin material and a metal material caused by baking after bonding of the resin members (58, 59) made of the resin material to the connecting plate (45). A link made of a composite material according to claim 7, characterized in that resin members (58, 59) made of the resin material are bonded to the front and back surfaces of the connecting plate (45), respectively, so as to cancel each other. Structure. 10. At least one prepreg layer (58, 59) made of a fiber reinforced resin having orientation directions of reinforcing fibers set in two directions intersecting each other is provided.
The link structure according to claim 5, characterized in that the two directions intersect the axis of the torque acting on (4) at substantially the same angle and are disposed on the operating portion (25). 11. A fiber reinforced resin having an orientation direction of reinforcing fibers defined in a circumferential direction of a substantially cylindrical surface having an axis parallel to an axis of torque acting on the joints (23, 24). The link structure according to claim 5, characterized in that at least one prepreg layer (65) connected to the operating portion (25) is provided around the joint main body (26, 34).