JP4481864B2 - Pipe-embedded robot hand and molding method thereof - Google Patents

Description

  The present invention relates to a robot hand made of a fiber reinforced resin material, and more particularly to a robot hand that enables intake / exhaust for vacuum suction of an object and wiring inside cables.

  A robot arm typified by an industrial robot manipulator has a robot hand (hereinafter sometimes abbreviated as “hand”) at the tip. The robot hand has its operation method and structure determined and used in accordance with various uses such as assembling machine parts, taking out and transporting products, or holding an object.

  Examples of the performance required of the hand in order to achieve the miniaturization of the robot and the high-speed operation include high rigidity, light weight, and high vibration damping rate. The high rigidity improves the positioning accuracy of the hand, shortens the time, and avoids resonance. The light weight can reduce the actuator output such as the torque of the drive motor, thereby reducing the weight and energy saving of the entire robot, and also contributing to the improvement of the rigidity of the hand. The high vibration damping rate contributes to shortening the positioning time and improving the work accuracy by early attenuation of minute vibrations during positioning.

  In general, robot hands are often made of metal materials such as aluminum (aluminum) and stainless steel (SUS) from the viewpoint of durability, cost, workability, etc. From the viewpoint, various inventions of hands using fiber reinforced resin (FRP) as a material have been proposed in recent years.

  For example, the prior art document 1 (Patent Document 1: Registered Utility Model Publication No. 3073229) describes a device related to a robot hand having a square tube aggregate structure of carbon fiber reinforced plastic (CFRP) material. In this device, there is shown a vacuum suction-type robot hand for a transfer device having a vacuum pad at the distal end and a base end and a distal end communicating with each other through a square tube.

  Prior Document 2 (Patent Document 2: Japanese Patent Application Laid-Open No. 11-10687) describes an invention related to a robot arm made of CFRP material having a hollow portion that accommodates an intake / exhaust pipe and a conductive cable therein. . In this invention, two thin concave (saddle-shaped) members facing each other are bonded by a flange portion, and a hollow portion for accommodating various pipes and cables is widely provided inside the arm.

Prior Document 3 (Patent Document 3: Japanese Patent Laid-Open No. 2000-24983) relates to a robot arm in which bending and torsional rigidity is enhanced by improving the robot arm described in Prior Document 2 to have a channel-shaped cross-sectional shape. The invention has been described.
Registered Utility Model Gazette No. 3073229 Japanese Patent Laid-Open No. 11-10687 Japanese Patent Laid-Open No. 2000-24983

  As an invention for inserting a vacuum suction intake / exhaust pipe and / or a signal line of various sensors, a conductive power cable, and the like into a robot hand made of FRP material, three types of methods have been proposed. The first method is a method in which a robot hand is formed by an FRP tube having a rectangular cross section and a vacuum suction port or a wiring port is formed at the tip as in the device described in the prior art document 1. The second method is a method in which a concave FRP member is joined, a hollow portion is provided inside a thin robot hand, and a pipe or the like is passed through, as in the inventions described in the prior art documents 2 and 3.

  As shown in FIGS. 8 and 9, the third method is a method in which a groove 120 is provided in the solid member 110 and covered with a lid 140 made of metal or FRP to form a pipe. FIG. 8 is a plan view of the robot hand, and FIG. 9 is a transverse sectional view (BB sectional view) orthogonal to the longitudinal direction of the hand. A through hole 131 used for a vacuum suction port or a wiring port is formed at the tip of the robot hand, and a vacuum pad unit 130 is provided as necessary. By vacuuming the groove 120 with a vacuum pump or the like, the object can be adsorbed to the vacuum pad portion 130 and gripped.

  However, each of these conventional techniques has the following problems, and the mechanical performance of the robot hand cannot be obtained sufficiently. That is, in the case of the first method, since the FRP material is inferior in airtightness to the metal material, ambient air enters from the layers or voids of the laminated prepreg constituting the FRP tube, thereby reducing the vacuum adsorption performance. This phenomenon becomes more prominent due to generation of microcracks in the FRP material due to long-term use of the robot hand or distortion of exhaust moisture, and becomes a factor that determines the product life of the hand.

  In the case of the second method, the hollow space formed by the concave FRP member is large, and flexible piping is exposed to the inside of the arm during the operation of the robot arm. As a result, the outer skin of the piping is damaged, and in the worst case, air leaks from the intake and exhaust pipes. Even when the piping is rigid, in the structure in which the arm and the piping are in contact with each other only at the distal end and the proximal end, the load applied to the contact portion during operation of the arm is large, and premature wear of the FRP base material of the arm is likely to occur. In addition to the fact that the rampage of the piping damages the FRP inner wall of the arm and causes dust to deteriorate the manufacturing environment of the object, the movement of the piping within the arm causes a shift in the center of gravity of the arm. It becomes a problem. This is because if the position of the center of gravity of the arm is shifted, the moving speed changes when driven by the same actuator torque. In addition, the hollow thin robot arm has a larger moment of inertia than the solid arm when compared with the same mass, and therefore requires a large initial motion torque of the drive motor. Furthermore, because of its thin wall, the arm as a whole has high bending rigidity and torsional rigidity. However, when working with robots, especially when gripping an object, local natural vibration of the arm is likely to occur, and it is necessary to wait for the arm to be positioned. There is a problem that it takes a lot of time.

  In the case of the third method shown in FIG. 9, in addition to the problem that ambient air is more likely to enter and exit from the layers or voids of the laminated material (160) as in the first method, it is from between the lid 140 and the solid member 110. In particular, air leakage (150) is likely to occur when it is deformed / deteriorated over time. In addition, when the lid 140 is made of a metal material such as SUS or aluminum, the linear expansion coefficient (CTE) differs from the FRP material 110 by about an order of magnitude or more. Therefore, depending on the working environment of the robot, the hand warps due to temperature changes. This is a factor that reduces work accuracy. In addition, when the groove 120 is used only for cable wiring, the airtightness inside the hand is unnecessary, so it is possible to select the open cross section without the lid 140. As a result of the cutting, a new problem arises in that the bending and twisting rigidity of the entire robot hand is lowered.

  Based on the above, in the present invention, it has a high vacuum suction force on the object, can stably hold the cables routed inside, and has high specific rigidity, which improves positioning accuracy and time. An object of the present invention is to provide a robot hand having a small moment of inertia.

  Therefore, in order to solve the above problems, the present inventor has intensively studied, and by embedding a highly airtight pipe integrally with the base material of the robot hand made of FRP material having high specific rigidity, The present invention has been completed on the basis of the knowledge that it does not require airtightness and can prevent the wear of the base material due to the rampage of the piping.

That is, according to the following invention, the above-described problems can be solved.
(1) A robot hand whose base material is a fiber reinforced resin material,
One or a plurality of pipes made of a material that is more airtight than the base material are embedded and molded from the base end part to the front end part, and the front end part extends from the outer surface of the base material to the pipe. Robot hand characterized by having a through hole.

The present invention includes the following related inventions as specific embodiments thereof.
(2) The fiber reinforced resin material is a carbon fiber reinforced plastic formed by heating and pressure forming a laminated prepreg sheet, and
The robot hand according to (1), wherein the highly airtight material is a metal material or a hard plastic material.

(3) A robot hand whose base material is a fiber reinforced resin material,
A prepreg sheet that is laminated with a pipe made of a material that is more airtight than the base material sandwiched between the base end and the front end is integrally heated and pressure-molded, and the outer surface of the base material is formed at the front end. A robot hand comprising one or a plurality of through holes extending from a pipe to a pipe.

(4) Using a fiber reinforced resin material as a base material,
A pipe made of a material that is more airtight than the base material, extending from the base end to the front end,
A pair of intermediate members sandwiching this by its side surfaces from the left and right along the longitudinal direction;
A pair of surface plates sandwiching the pipe and the intermediate member from above and below along the longitudinal direction;
An adhesive layer that joins the upper / lower surface of the intermediate member and the inner surface of the face plate to each other;
Is a robot hand formed by pressing and molding (cocure) integrally,
One or a plurality of through holes extending from the outer surface of one surface plate to the pipe are formed in the tip portion, and
The robot member according to claim 1, wherein the intermediate member and the surface plate are obtained by heating and pressure-molding (precuring) the fiber-reinforced resin material in advance.

(5) The robot hand according to (4), wherein the adhesive layer is a cross prepreg sheet of the fiber reinforced resin material.

(6) The robot hand according to any one of (3) to (5), wherein the fiber reinforced resin material is a carbon fiber reinforced plastic, and the highly airtight material is a metal material or a hard plastic material.

(7) a first step of laminating a prepreg sheet of fiber reinforced resin material with a metal or plastic pipe extending between the base end portion and the tip end portion;
A second step of integrally heating and pressure forming these,
A third step of drilling one or more through holes from the outer surface to the pipe at the tip;
A robot hand molding method comprising:

(8) a first step of obtaining a pair of intermediate members and a pair of surface plates by heating and pressure molding (precuring) the laminated fiber reinforced resin prepreg sheet;
A second step of sandwiching a pipe made of metal or plastic extending from the base end portion to the tip end portion between the side surfaces of the pair of intermediate members along its longitudinal direction;
A third step of sandwiching the pipe and the intermediate member from above and below along the longitudinal direction with the pair of surface plates through an adhesive layer;
A fourth step of integrally heating and pressing (cocure) these, and
A fifth step of drilling one or more through holes from the outer surface of one surface plate to the pipe at the tip;
A robot hand molding method comprising:

  According to the robot hand according to the present invention, a fiber reinforced resin material having a high specific rigidity and specific strength and a high vibration damping rate is used as a base material as compared with metal materials such as aluminum and SUS that are generally used conventionally. By improving rigidity, avoiding resonance, avoiding resonance, improving load resistance by improving strength, downsizing the entire robot by reducing actuator output by reducing weight, shortening positioning time by improving vibration damping performance, etc. Is obtained.

  Further, the robot hand according to the present invention is formed by embedding a pipe made of a material having higher airtightness than the base material, extending from the base end portion to the tip end portion, and piping from the outer surface of the base material to the tip portion. One or a plurality of through-holes are formed. If the pipe is evacuated from the base end with a vacuum pump or the like, the object to be gripped by the hand (hereinafter referred to as “target object”) is vacuum-sucked into the tip through-hole and gripped. Can do. It is also possible to insert signal lines, power cables, and the like of various sensors from the through hole toward the base end through a pipe embedded in the hand. If these cables jump out of the hand, there is a risk of contact with the hand, arm, or object during robot operation. Is.

  In the robot hand according to the present invention, a material having higher airtightness than the base material is used for the piping. In the present invention, “high airtightness” means that the test piece cut into the same thickness and shape has high air permeability (low air permeability). The magnitude of the air permeability can be compared according to the time (seconds) required for 300 ml of air to pass through a circular test piece having a diameter of 10 mm according to the JISP 8117 standard. Thereby, airtightness can be ensured by the piping itself, and a decrease in vacuum adsorption performance due to intrusion of air from the interlayer or void of the FRP laminated material, which has been a problem of the prior art, can be prevented.

  Furthermore, in the robot hand according to the present invention, the piping is integrally embedded in the base material of the hand. In the present invention, “integrally” means a state in which the pipe cannot be inserted into and removed from the base material without destroying the hand, and a state in which the entire length of the pipe inside the hand is in contact with the base material. However, as long as the pipe is not violated and collides with the base material, a state where a part of the pipe is not in contact with the base material is included. In addition, “the hand is embedded in the base material” means that the pipe is embedded in the base material from the base end to the tip of the hand. However, as long as the rigidity of the entire hand is not reduced, a part of the pipe is included. Including the state of being exposed from the base material. It should be noted that a state in which the pipe projects beyond the tip of the hand or toward the robot from the base end is a natural mode and includes this state.

  By performing such integral embedding molding, the base material and the pipe are in contact with not only both ends of the hand, but also the whole or almost the whole, directly or via a filler, so that the pipe is flexible or rigid. Regardless, the pipe will not be violated and collide with the hand base material during robot operation. For this reason, generation | occurrence | production of the dust by wear of a preform | base_material inner wall can be prevented. In addition, since the piping is embedded integrally with the base material and the cables are inserted into the piping when necessary, the play of the cables in the hand can be minimized. As a result, it is possible to reduce the internal disturbance caused by the cable irregularly colliding with the inner wall surface of the hand during the robot operation and the hysteresis due to the movement of the cable. Further, even if the cables are displaced relative to the hand and collide with the hand in the play, the cables contact the inner wall of the pipe and not the base material, so the FRP material wears and becomes dusty. There is an advantage of not generating.

  In addition, by piping and embedding a pipe having a predetermined rigidity into the base material, the base material is additionally given the rigidity of the pipe, and a compact and dense robot hand can be obtained as a whole. This eliminates local natural vibrations that were likely to occur with conventional hollow robot hands, and can reduce the initial torque of the actuator by reducing the moment of inertia of the hand. Solved. In addition to the hollow robot hand, for example, when compared with a method in which piping is joined to the outer surface of the base material of the hand, the integrally embedded type of the present invention suppresses the thickness of the hand and can be operated by saving space of the robot. It is excellent in making it possible.

  Embodiments of the present invention will be described. In the present invention, the fiber reinforced resin material used for the base material of the robot hand is a carbon fiber reinforced plastic formed by heating and pressure molding a laminated prepreg sheet, and the material of the pipe is a metal material or a hard plastic A material is preferred. By adopting a method of heating and pressure-molding a prepreg sheet of carbon fiber reinforced plastic, it is easy to make a robot hand that has particularly enhanced rigidity in any direction, such as the longitudinal direction of the hand, based on a predetermined orientation design of the reinforcing fiber Can get to.

  The thickness of the pipe is generally on the order of submillimeters (0.1 mm) or millimeters (1 mm) because of environmental resistance requirements during heating and pressure molding. The air permeability of the material (JISP 8117 standard) is so large that it can be approximated to infinity. On the other hand, FRP, which is a composite material of reinforcing fibers (fibers) and resin (matrix), is inferior in airtightness mainly due to voids generated at the boundary between the fibers and the matrix, and such values are relatively low. Further, when the hand base material is obtained by lamination of prepreg sheets, the airtightness between the layers is inferior to one order or more than the fiber: matrix boundary inside the material.

  From the above, one of the problems of the prior art of lowering the vacuum adsorption performance due to air leakage from the base material by making the piping material a metal material such as SUS or aluminum, or a hard plastic such as polypropylene or polycarbonate, for example. Solved. In the present invention, “hard plastic” means a plastic having a bending elastic modulus of 700 [MPa] or more in a steady state. Since the pipe material has a predetermined rigidity like a metal material or a hard plastic material, the cross-sectional shape of the pipe can be maintained even during pressure molding. Further, it is possible to prevent the piping from being deformed by the contact with the cables inserted inside after the molding.

  The robot hand according to the present invention uses a fiber reinforced resin (FRP) material as a base material, and a prepreg sheet that is laminated by sandwiching a pipe made of a material that is more airtight than the base material from the base end portion to the tip end portion. It is preferable that one or a plurality of through holes extending from the outer surface of the base material to the pipe are formed in the tip portion by heating and pressure forming integrally.

  By embedding highly airtight piping inside the base material from the base end portion to the front end portion and making a through hole in the front end portion, it is possible to vacuum-suck the object and route the cables. In addition, by adopting a method in which a plurality of prepreg sheets of FRP material are laminated to obtain a base material, the piping is easily embedded by simply sandwiching the piping between them and heating and pressurizing (cocure) them together. And the object of the present invention can be achieved.

  It is possible to form the through hole in advance by providing a through hole in the prepreg or piping, but it is rather preferable to form a through hole that reaches the piping from the base material surface after molding. It can be said that it is preferable because the influence of thermal deformation generated in the material at the time of molding can be eliminated and the positional accuracy can be increased.

  The robot hand according to the present invention is preferably configured by using an intermediate member and a surface plate obtained by heating and pressure molding (precuring) a fiber reinforced resin (FRP) material as a base material. In this case, a pipe made of a material that is more airtight than the base material is first sandwiched between the side surfaces of the pair of intermediate members from the left and right along the longitudinal direction. Furthermore, these are sandwiched between a pair of surface plates, and the upper / lower surface of the intermediate member and the inner surfaces of the two surface plates are integrally heated and pressure-molded (cocure) via an adhesive layer that joins each other. The piping can be easily embedded in the base material from the base end portion to the tip end portion. Furthermore, a robot hand capable of vacuum suction of objects and routing of cables by drilling one or a plurality of through holes from the outer surface of one surface plate to the pipe at the tip. can get. However, the timing of providing the through holes is not limited to before or after pre-curing or co-curing as described above, but is preferable from the viewpoint that it is possible to provide through holes with high positional accuracy most easily after co-curing. It is.

  By adopting this method, the surface plate and the intermediate member can be made of different FRP materials or different fiber orientations even if they are the same material. For example, the intermediate member has high rigidity in the out-of-plane compression direction of the hand. In addition, since the surface plate can be freely designed, for example, by increasing the rigidity in the longitudinal direction, particularly in the compression and tension directions in the longitudinal direction, various specifications of the robot hand can be satisfied.

  That is, if the surface plate and the FRP material of the intermediate member are different from each other as described above, or if the fiber orientation is extremely changed even with the same material, the linear expansion coefficient (CTE) of the two is greatly different. Due to If a plurality of types of prepreg sheets having significantly different CTEs are simply laminated, and piping is embedded and cured, large thermal strain and thermal stress are generated in the cooling process after pressurization, causing delamination and material destruction. Therefore, the surface plate and the intermediate member are preliminarily molded (precured) with a predetermined material, and these are integrally bonded (cocure) with the adhesive layer, whereby absorption of the thermal stress due to the shear deformation of the adhesive layer can be expected. In addition, since the pre-curing of the surface plate and the intermediate member is performed individually, it is performed at a sufficiently high temperature. Generally, since the co-curing temperature can be lower than that, the thermal stress generated between the surface plate and the intermediate member itself is reduced in the first place. Can be made.

  As the adhesive layer used in the present invention, it is also preferable to use a cross prepreg sheet made of FRP material in addition to a normal adhesive such as inorganic or organic. Since the cross prepreg sheet is knitted with reinforcing fibers in the 0 ° direction and 90 ° direction, by thinly laminating between the surface plate and the intermediate member and curing, the inner surface of the opposing surface plate and the surface of the intermediate member However, even if it is a different material or a different fiber orientation, it can be expected to function as a buffer layer that suitably absorbs the generated thermal stress.

  As described above, a pipe-embedded robot hand can be obtained by sandwiching pipes between layers of prepreg sheets and curing, or by enclosing a pipe with a pre-cured surface plate or an intermediate member and using an adhesive layer. In these cases, carbon fiber reinforced plastic (CFRP) is used as the fiber reinforced resin material used for the base material, and metal material or hard plastic material is used as the highly airtight material used for the piping. Is preferred. This is because high specific rigidity, specific strength, and vibration damping properties can be obtained by using CFRP as a base material, and high airtightness and rigidity can be obtained by using a metal material or a hard plastic material for piping.

  The method of obtaining the robot hand according to the present invention is not limited to one, but a first step of stacking prepreg sheets of FRP material with a pipe sandwiched therebetween, a second step of co-curing these together, A pipe-embedded robot hand that achieves the object of the present invention can be suitably obtained by a molding method comprising a third step of drilling one or more through holes from the outer surface to the pipe at the tip. it can.

  As another method, the first step of precuring the laminated FRP prepreg sheet to obtain a pair of intermediate members and a pair of surface plates, and sandwiching the piping between the side surfaces of the pair of intermediate members along the longitudinal direction thereof A second step, a third step in which the pipe and the intermediate member are sandwiched between the pair of surface plates from above and below along the longitudinal direction via the adhesive layer, a fourth step in which these are integrally cured, and a tip A pipe-embedded robot hand that achieves the object of the present invention also by a molding method comprising a fifth step of drilling one or a plurality of through holes from the outer surface of one face plate to the pipe in the part. It can be suitably obtained.

  By adopting these molding methods, the robot hand according to the present invention can be obtained. In addition, the hand is suitably formed including that the through holes can be easily positioned.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings. However, the present invention is not limited to the following embodiments, particularly regarding the planar shape and cross-sectional shape of the robot hand, the shape and number of pipes embedded therein, the position and number of through holes, the presence or absence of a vacuum pad portion, etc. .

  About the whole shape of the robot hand concerning this invention, a side view is shown to Fig.1 (a), and the top view of a back surface is shown to the same figure (b). FIG. 2 shows the shape of a cross section (cross section) perpendicular to the longitudinal direction. FIG. 2 corresponds to the AA cross section of FIG.

  10 is a base material made of FRP material, 20 is a pipe integrally embedded in the base material, 30 is a vacuum pad portion, 31 is a through-hole on the tip side used as a vacuum suction port or wiring port, and 40 is a base end portion Represents the side outlet hole.

  FIG. 1 shows a bifurcated plate-like robot hand, which has four vacuum pad portions 30, and by pulling out air in the pipe 20 from the outlet hole 41, an object not shown is gripped by vacuum suction. Can do. Although a target object is not specifically limited, A resin product, a liquid crystal product, a semiconductor product, or these semi-finished products, materials, etc. can be illustrated as a suitable thing. However, the vacuum pad unit 30 may be provided according to the purpose of use of the object and the hand, and is not an essential component. In addition, the lead-out hole 41 is an end portion on the proximal end side of the pipe 20 and is connected to a robot main body or the like, and may be subjected to interface processing such as a spiral or a diaphragm as necessary.

  The base material 10 is made of a fiber reinforced resin (FRP) material in which a reinforced fiber (fiber) is impregnated with a matrix (resin, resin). As a result, advantages such as specific strength, specific rigidity, heat distortion resistance, corrosion resistance, chemical resistance, and high vibration damping properties over metals such as SUS and aluminum can be obtained by appropriate setting of matrix and reinforcing fiber type and fiber orientation. The enjoyed robot hand can be obtained.

  Examples of the FRP material matrix include epoxy resin (EP), phenol resin (PF), unsaturated polyester resin (FRP), alkyd resin, bismaleimide resin (BMI), cyanate resin, silicone resin, polyimide resin (PI), Or thermosetting resin such as polyurethane resin (PUR), or polyamide (PA), polyacetal (POM), polypropylene (PP), polysulfone (PSF), polybutylene terephthalate (PBT), polycarbonate (PC), polyphenylene sulfide (PPS) ), Polyetheretherketone (PEEK), polyetherimide (PEI), polyethersulfone (PES), polyamideimide (PAI), polyarylate (PAR), polyaryleneketone, polyarylenesulfur Id or among thermoplastic resins such as polyester (PET) by selecting one from, or can be used in mixtures of two or more. Among these, an epoxy resin or a cyanate resin is preferably used from the viewpoints of strength, moldability, and availability.

  For example, carbon fibers, aramid fibers, Kevlar fibers, natural fibers, boron fibers, ceramic fibers, silicon carbide fibers, or alumina fibers are used as reinforcing fibers (fibers) used in the FRP material.

  These reinforcing fibers may be any one type or a mixture of plural types, and the fiber length may be short fibers or long fibers, but from the viewpoint of increasing the specific strength and specific rigidity of the robot hand, carbon fibers It is preferable to use an aramid fiber or a silicon carbide fiber as the long fiber.

  A method for obtaining the base material 10 by combining the reinforcing fiber and the matrix resin is not particularly limited. For example, the reinforcing fibers can be braided three-dimensionally into the shape of a robot hand with the pipe 20 inserted therein, and this can be impregnated with a matrix resin. In addition, a molding method in which reinforcing fibers are aligned in one direction and a plurality of sheet-like prepregs impregnated with a matrix resin to be in a semi-cured state is appropriately laminated based on a predetermined fiber orientation design is an arbitrary method. This is preferable from the viewpoint that a robot hand having a particularly enhanced direction (for example, the longitudinal direction of the hand) can be easily obtained. Moreover, you may use combining the multiple types of prepreg which changed the combination of the matrix and the reinforced fiber.

  In the lamination of the prepreg sheets, as described later, in addition to the method of laminating the prepreg sheets of the FRP material by sandwiching the pipe 20 and heating and pressurizing them together, a plurality of prepreg sheets are preliminarily molded (precured). A method of combining the surface plate and the intermediate member obtained in this manner so as to surround the pipe 20 around the axis and integrating them through the adhesive layer (cocure) can also be selected. However, when a plurality of surface plates and intermediate members are used, it is possible to pre-cure and use different FRP materials for the paired surface plates, between the intermediate members, or between the surface plate and the intermediate member.

  The shape of the robot hand, that is, the shape of the base material 10 is not particularly limited. 1 and 2 exemplify a bifurcated plate-like hand having a rectangular cross section. However, the shape is not limited to this, and the shape in plan view is linear, tapered, arc-shaped, crescent-shaped, disk-shaped, polygonal (bifurcated) Or a part thereof, or a combination thereof. Also, the cross-sectional shape is not limited to the rectangle shown in FIG. 2, and may be a circle, a semicircle, a part of these, or a combination thereof, and the shape and size may vary depending on the part.

  The pipe 20 is made of a material that is more airtight than the base material 10. The specific material is not particularly limited, but a metal material or a hard plastic material is preferable from the viewpoint of airtightness (air permeability) and rigidity. Although the metal material is not particularly limited, for example, SUS, aluminum, iron, copper, titanium, magnesium, or an alloy thereof is preferably used from the viewpoint of availability, workability, and durability. The hard plastic material is not particularly limited, and polypropylene, polycarbonate, ABS resin, acrylic resin, nylon resin, polyimide resin, or the like is preferably used from the viewpoints of availability, workability, heat resistance, rigidity, and the like. The air permeability, which is a measure of hermeticity, is measured and compared in accordance with JISP 8117. Compared to the base material 10 formed by stacking prepreg sheets of FRP material as described above, Since a hard plastic material generally has an air permeability of one order or more, a robot hand having a high vacuum suction performance with less air leakage can be obtained by embedding the pipe 20 made of such a material in the base material.

  The cross-sectional shape and the plan view shape of the pipe 20 can be freely designed according to the purpose of use and the required specifications of the robot hand. The cross-sectional shape is not limited to the rectangle shown in FIG. 2, and may be a circle, a semicircle, a polygon, a part of these, or a combination thereof, and the shape and size may vary depending on the part. Since the pipe 20 is embedded in the base material 10, in principle, the cross section is surrounded by the cross section of the base material 10, but a part thereof may be exposed from the base material 10.

  The plan view shape of the pipe 20 can be appropriately selected according to the plan shape of the robot hand including the Y shape shown in FIG. Further, the side view shape of the pipe 20 is linear in FIG. 1A, but is not limited to this. For example, it is also preferable that a protruding portion is provided by bending or constricting at the tip of the hand and inserted into the through hole 31. is there.

  The treatment of the outer surface of the pipe 20 is not particularly required. For example, in the case of a metal material, in addition to a mechanical polishing process such as a general wire brush or a sander, a degreasing process, a chemical conversion process such as sulfurization or oxidation, Plating treatment such as rust prevention, anodizing treatment, surface effect treatment, film treatment, etc. may be performed before molding to improve the contact with the base material 10.

  The through-hole 31 is a hole for vacuum suction of an object or for inserting cables into or out of the hand. In order to vacuum-suck the object, the air in the pipe 20 is extracted from the outlet hole 40 on the hand base end side, and the inside of the pipe 20 is set to a negative pressure. A vacuum pump or the like is used for such air venting, but its means is not particularly limited. When the object is attracted and gripped so as to be suspended from above, the through hole 31 is formed in the lower surface of the hand. Conversely, when the object is placed and held on the hand, the through hole 31 is formed in the upper surface of the hand. It is good to install. However, the position and number of the through holes 31 are not limited, for example, it is possible to provide the through holes 31 on the side of the hand and suck the object to the hand, and according to the use purpose and required specifications of the robot hand. Can be designed freely.

  When the through hole 31 and the outlet hole 40 are provided, a block made of a metal material or a resin material is provided at the distal end portion and / or the proximal end portion of the pipe 20 so that the suction air does not leak from the base material 10. More preferably, it is embedded in the material 10. In this case, the pipe 20 is connected to one end of the block embedded in the tip, and the vacuum pad 30 is provided by countersinking the other end or the side surface, thereby providing an airtightness in the airway from the vacuum pad to the pipe. The low base material 10 and suction air do not contact. In addition, a similar block is embedded in the base end portion, the pipe 20 is connected to one end thereof, and interface processing for robot connection is applied to the other end or the side surface so that the mother having low airtightness is also provided in the vicinity of the outlet hole 40. It is avoided that the material 10 and the suction air come into contact with each other to cause an air leak.

  It is preferable to provide a vacuum pad portion 30 at the tip of the through hole 31 in order to increase the contact area with the object and not damage the surface of the object. In FIG. 1, the vacuum pad itself is omitted, and only the mounting portion is shown. The vacuum pad can be made of rubber, non-woven fabric, sponge, resin, or the like depending on the material, mass, surface shape, etc. of the object, but is not particularly limited.

  Since the vacuum suction force is determined by the opening area of the vacuum pad portion × (atmospheric pressure−in-pipe pressure), increasing the contact area with the object by providing the vacuum pad portion 30 at the tip of the through hole 31 is vacuum suction. It can also be said that it is preferable from the viewpoint of increasing the power. The object that has been vacuum-adsorbed is moved to a predetermined location by operations such as turning and raising / lowering of the robot hand, and when the intake air is drawn into the pipe 20 from the lead-out hole 40 at that position, the pressure in the pipe is recovered, and the object is recovered. Detaches from the hand due to its own weight.

  That is, when the object is moved by a vacuum suction type robot hand, (1) the hand is brought close to or in contact with the object, (2) the object is sucked by sucking the object through the outlet hole 40, and (3) the object is gripped. Can be performed by a simple operation of moving (4) sucking air from the outlet hole 40 and detaching the object. Here, according to the robot hand according to the present invention, since the pipe 20 is highly airtight, the gripping force of the object is high, and the pressure in the pipe recovers during the movement of the object, causing the object to fall off accidentally. There is nothing. Further, the high airtightness means that the response to intake / exhaust from the outlet hole 40 is improved, and the object can be grasped and desorbed following the higher-speed robot operation.

  Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 3 is a cross-sectional view of the robot hand according to the first embodiment, showing a state where the pipe 20 is embedded in the base material 10. The through holes 31 and the vacuum pad portion 30 are omitted. The base material 10 is formed by laminating a unidirectional reinforcing prepreg sheet (UD material) of a carbon fiber composite material (CFRP), and the fiber orientation is the + 30 ° direction with respect to one layer in the longitudinal direction (0 ° direction) of the hand. Each of the −30 ° directions was set as a ratio of one layer (0 °, ± 30 °). An epoxy resin was used for the matrix of the prepreg sheet. The side surface and the plan view shape of the base material 10 were formed in the shape of a bifurcated plate similar to that shown in FIG. 1, the thickness was about 5 mm, and the widths of the two hand tips were about 30 mm.

  An SUS rectangular tube having an outer dimension of 10 mm in width, 3 mm in thickness, and 0.5 mm in thickness was used as the pipe 20 in a bifurcated manner, and was sandwiched between the prepreg sheet layers (first step). However, the distal end of the rectangular tube is closed and only the proximal end side is open. The outer surface of the pipe 20 was treated with an epoxy primer to improve the adhesion with the base material 10. The portion where the pipe 20 is sandwiched includes a method of laminating a prepreg sheet cut in accordance with its shape, and a method of bypassing the prepreg sheet so as to wrap around the pipe 20 without cutting. Moreover, the surroundings of the piping 20 were filled with an epoxy resin putty mixed with glass powder as a filler to fill a gap with the prepreg sheet. The pipe 20 was sandwiched between substantially the center in both the thickness direction and the width direction of the base material 10. The pipe 20 extends from the proximal end portion of the hand to a position slightly ahead of the distal end portion in the out-of-plane direction of FIG.

  Heating and pressure molding were performed in a state where the pipe 20 was covered with the prepreg sheet and embedded integrally (second step). In this example, a pressing die (not shown) was used and a pressure of 30 [MPa] was applied. Further, the molding was performed for 180 minutes while the entire hand was heated to 130 [° C.] with a heater (not shown). After such forming, aging was performed at 80 [° C.] for 120 minutes, and in particular, the thermal stress generated between the pipe 20 and the base material 10 was removed.

  After the molding, as shown in FIG. 1B, a total of four through-holes 31 having a diameter of 5 mm were drilled from the back surface to the tip of the hand with a depth penetrating the lower surface of the pipe 20 (third process). Furthermore, a vacuum pad portion 30 having a diameter of 10 mm and a depth of 0.5 mm was provided on the outer surface of the back surface of the hand, and a sponge made of the same PVA foam was fitted into the vacuum pad.

  With respect to the robot hand obtained by such a molding method, when a commercially available vacuum pump is connected to the base end of the pipe 20 and the air in the pipe 20 is exhausted, the object is vacuum-adsorbed, so that suitable suction, gripping and conveyance are achieved. Work was performed, and no air leak from the pipe 20 was observed. As an object, an injection molded plastic resin product was used.

  FIG. 4 is a cross-sectional view of the robot hand according to the second embodiment. The side view shape and the plan view shape of the robot hand are the same as those in the first embodiment.

  The robot hand according to the present example was molded as follows. That is, first, the CFRP prepreg sheet was heated and pressure-molded (precured) to obtain the surface plates 11 and 12 and the intermediate member 13 (first step). The surface plates 11 and 12 have reinforcing fibers oriented in the longitudinal direction of the hand (0 ° direction: out-of-plane direction in FIG. 4), and cross prepreg sheets (oriented in 0 ° and 90 ° directions) are laminated on the innermost and outermost layers. And performed a pre-cure. Each thickness was 1 mm. The molding environment was a pressure of 30 [MPa], a temperature of 180 [° C.], and a time of 180 minutes.

  The intermediate member 13 was prepared by impregnating unsaturated polyester resin into randomly oriented long glass fibers and cutting out a pre-cured glass fiber reinforced plastic (GFRP) into a rectangular cross section having a thickness of 5 mm. Such a material has the advantages of high vibration damping rate, light weight and excellent compressive strength.

  An SUS circular tube having an outer diameter of 5 mm and a wall thickness of 0.5 mm was used for the pipe 20, and the space between the intermediate member 13 was filled with the same filler as in the first example. Along the longitudinal direction of the pipe 20, the pipe 20 was fixed by being sandwiched between the side surfaces of the pair of opposed intermediate members 13 (second step).

  Further, a CFRP cross prepreg sheet was sandwiched between the upper / lower surface of the intermediate member 13 and the inner surfaces of the surface plates 11 and 12 as an adhesive layer 14, and the whole was sandwiched between the surface plates 11 and 12 (third step).

  These were cured for 120 minutes in a molding environment with a pressure of 30 [MPa] and a temperature of 130 [° C.] using a pressing die and a heater (not shown) (fourth step). Thereafter, aging was performed in the same environment as in the first example.

  The molded hand was provided with a through hole 31 and a vacuum pad portion 30 at the same location as in the first embodiment (fifth step).

  A high vacuum suction force was also obtained for the robot hand obtained by this molding method, as in the first example.

  When the pipe 20 is sandwiched using the precured surface plates 11 and 12 and the intermediate member 13 and these are integrally cured, the shape of the surface plate and the intermediate member is not particularly limited. 5 and 6 show a case where a circular pipe is used as the pipe 20. In FIG. 5, an example in which the diameter of the circular pipe is larger than the thickness of the intermediate member 13, and conversely in FIG. 6, a small example is shown. Yes. In FIG. 5, shaving grooves are provided in the surface plates 11 and 12 to form relief portions of the pipe 20. Such a relief portion may have a cylindrical surface shape in accordance with the shape of the pipe 20. With this structure, the thickness of the surface plate can be freely increased regardless of the size of the pipe 20, and the rigidity in a predetermined direction can be further strengthened. In the case of FIG. 6, the surface plates 11 and 12 are provided with lid-shaped protrusions so that the pipe 20 contacts the surface plate or the intermediate member from four directions. By adopting such a key-type fitting structure, the surface plate and the intermediate member are integrally formed more firmly.

  FIG. 7 shows a case where a composite square pipe is used as the intermediate member 13. The pipe 20 is also a square pipe having the same height, but is not limited to this. By adopting such a structure, the intermediate member 13 can be reduced in weight. Further, the hollow portion of the intermediate member 13 having poor airtightness can be used for routing cables, and the highly airtight piping 20 can be used for vacuum suction.

  In any of the embodiments shown in FIGS. 5 to 7, it is possible to reduce the generation of thermal stress by preliminarily molding the surface plates 11 and 12 and the intermediate member 13 individually in a high temperature and high pressure environment. it can. When the pipes 20 are embedded and integrally molded (cocure), they can be performed in a looser molding environment, and the thermal stress is further increased by the action of the adhesive layer 14 made of an adhesive or a cross prepreg sheet. It is because it is absorbed.

  The robot hand according to the present invention can hold various objects by vacuum suction, and can route various signal lines and power cables inside the hand. Also, the robot type can be widely used regardless of whether it is a sequence robot, a playback robot, a numerical control robot, an industrial robot such as an intelligent robot, or a personal robot.

Side view (a) and plan view (b) of a robot hand according to an embodiment of the present invention Cross-sectional view of a robot hand according to an embodiment of the present invention 1 is a cross-sectional view of a robot hand according to a first embodiment of the present invention. Cross-sectional view of a robot hand according to a second embodiment of the present invention Cross-sectional view of a robot hand according to another embodiment of the present invention. Same as above Same as above Plan view showing the structure of a conventional robot hand Sectional view showing the structure of a conventional robot hand

Explanation of symbols

10, 110 Base material 11, 12 Surface plate 13 Intermediate member 14 Adhesive layer 20 Piping 30, 130 Vacuum pad portion 31, 131 Through hole 40 Lead-out hole 120 Groove 140 Lid 150, 160 Air leakage

Claims (4)

Using fiber reinforced resin as a base material,
A pipe made of a material that is more airtight than the base material, extending from the base end to the front end,
A pair of intermediate members sandwiching this by its side surfaces from the left and right along the longitudinal direction;
A pair of surface plates sandwiching the pipe and the intermediate member from above and below along the longitudinal direction;
An adhesive layer that joins the upper / lower surface of the intermediate member and the inner surface of the face plate to each other;
A robot hand that is integrally heated and pressure-molded (cocure),
One or a plurality of through holes extending from the outer surface of one surface plate to the pipe are formed in the tip portion, and
The robot member according to claim 1, wherein the intermediate member and the surface plate are obtained by heating and pressure-molding (precuring) the fiber-reinforced resin material in advance.   The robot hand according to claim 1, wherein the adhesive layer is a cross prepreg sheet of the fiber reinforced resin material.   The robot hand according to claim 1, wherein the fiber reinforced resin material is a carbon fiber reinforced plastic, and the highly airtight material is a metal material or a hard plastic material. A first step of heating and pressure molding (precuring) the laminated fiber reinforced resin prepreg sheet to obtain a pair of intermediate members and a pair of surface plates;
A second step of sandwiching a pipe made of metal or plastic extending from the base end portion to the tip end portion between the side surfaces of the pair of intermediate members along its longitudinal direction;
A third step of sandwiching the pipe and the intermediate member from above and below along the longitudinal direction with the pair of surface plates through an adhesive layer;
A fourth step of integrally heating and pressing (cocure) these, and
A fifth step of drilling one or more through holes from the outer surface of one surface plate to the pipe at the tip;
A robot hand molding method comprising:

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