JP2017219177A - Uniaxial actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a uniaxial actuator that uses a metal guide rail to secure mechanical strength equivalent to that of existing uniaxial actuator and reduces weight.SOLUTION: In a uniaxial actuator, an FRP rolling member is joined to at least one of an inner peripheral surface of a rolling element rolling groove of a guide rail and an inner peripheral surface of a rolling element rolling groove of a slider by a filament winding method or sheet winding method; and a contact angle between the rolling member and a rolling element is 45° ±15°.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a uniaxial actuator formed by integrating a linear motion guide bearing and a screw type feeding device.

  The uniaxial actuator has a concave cross section and has a rolling rail rolling groove extending in the axial direction on the opposite inner side surface, and is arranged in parallel to the axial direction at a substantially central portion in the width direction of the guide rail. A screw shaft, a slider having a rolling element rolling groove facing the rolling element rolling groove of the guide rail, screwed to the screw shaft via a number of balls, and attached to both ends of the guide rail. And two support units that rotatably support the screw shaft. Then, when the screw shaft is rotated, the slider that is screwed with the screw shaft moves smoothly in the axial direction through the rolling of the ball.

  Conventionally, in a single-axis actuator, a guide rail, a screw shaft, a slider, and a ball are made of metal and are heavy. For this reason, for example, in a multi-axis configuration using a robot or the like, the load capacity of the motor increases, and the entire apparatus increases in size. It is also attempted to reduce the weight by making a member with a light metal or by making a hole in the guide rail, but there is a risk of increasing the material cost and reducing the strength.

  In order to reduce the weight, in Patent Document 1, the guide rail is made of fiber reinforced plastic (FRP), and a metal member is joined to the rolling element rolling groove.

Japanese Patent No. 4813373

  However, the FRP used for the guide rail in Patent Document 1 is obtained by dispersing reinforcing fibers in a resin, and is expected to have lower mechanical strength than a metal guide rail.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a single-axis actuator that uses a metal guide rail to ensure mechanical strength equivalent to that of the prior art and is reduced in weight.

In order to solve the above problems, the present invention provides the following uniaxial actuator.
(1) A cross-sectional view comprising a strip-shaped bottom plate extending in the axial direction and side walls vertically provided from both side portions of the bottom plate, and rolling element rolling grooves formed in the axial direction on the inner side surfaces of the both side walls. A concave guide rail, a screw shaft that is arranged in parallel to the axial direction inside the guide rail and has a helical thread groove on the outer peripheral surface, and the screw shaft attached to the guide rail is rotatable A support unit supported by the slider, a rolling element rolling groove facing the rolling element rolling groove of the guide rail, the slider screwed to the screw shaft, and the rolling element rolling groove of the guide rail facing each other A plurality of rolling elements interposed between the rolling elements of the slider and the rolling element rolling grooves of the slider, the slider axially extending along the guide rail via the rolling of the rolling elements In a single-axis actuator that can be moved to
At least one of the inner peripheral surface of the rolling element rolling groove of the guide rail and the inner peripheral surface of the rolling element rolling groove of the slider is formed of a reinforcing fiber filament bundle and a binder resin. A rolling member made of a molded body made of a filament sheet and a binder resin, or a laminated body of the layer made of the filament bundle and the sheet, and a molded body made of a binder resin is joined, and the rolling A uniaxial actuator, wherein a contact angle between a member and the rolling element is 45 ° ± 15 °.
(2) A plate-like upper rail joined to the inner peripheral surface on the upper side of the rolling element rolling groove and a plate joined to the inner peripheral surface on the lower side of the rolling element rolling groove. And is composed of a lower rail,
The uniaxial actuator according to (1) above, wherein the side surface of the lower rail is in contact with the lower end of the flat portion of the upper rail and has a V-shaped cross section.
(3) The uniaxial actuator according to (2), wherein a side surface of the lower rail is engaged with a stepped recess formed at a lower end of the flat portion of the upper rail.
(4) The uniaxial actuator according to (2) above, wherein the lower side of the flat portion of the upper rail and the lower rail has stepped recesses, and the stepped recesses are engaged with each other.
(5) A hook portion extending toward the transfer member is formed at both end edges of the rolling element rolling groove of the guide rail or both end edges of the rolling element rolling groove of the slider. The uniaxial actuator according to any one of (1) to (4) above.

  In the uniaxial actuator of the present invention, the guide rail is made of metal, has mechanical strength equivalent to that of the conventional one, and is made of a specific FRP made by a filament winding method or a sheet winding method by processing rolling element rolling grooves. Since the rolling members are joined, the metal material is reduced by the amount of processing and the weight is reduced. In addition, since the guide rail only needs to process the rolling element rolling groove of the conventional metal guide rail, the existing metal guide rail can be used and the cost is low. In addition, the specific FRP is superior in mechanical strength and wear resistance compared to the FRP in which the reinforcing fiber is dispersed in the resin, and further, the specific FRP rolling member and the rolling element are made of different materials. Since the contact occurs, the rolling element surface can be prevented from peeling without causing adhesion.

  Also, by joining a rolling member similar to the guide rail to the inner peripheral surface of the rolling element rolling groove of the slider, the mechanical strength of the slider is ensured, and further weight reduction of the uniaxial actuator as a whole is achieved. Can be planned.

It is a partially cutaway perspective view showing the entire structure of the uniaxial actuator of the present invention. It is sectional drawing which shows an example of the rolling member by the side of a guide rail including the periphery of the rolling element rolling groove | channel of a guide rail. It is sectional drawing which shows the other example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows the further another example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows the further another example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows the further another example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows the rolling-element rolling groove by the side of a guide rail provided with a hook part. It is sectional drawing which shows an example of the rolling member by the side of a slider including the periphery of the rolling element rolling groove | channel of a slider. It is sectional drawing which shows the other example of the rolling member by the side of a slider according to FIG. FIG. 9 is a cross-sectional view showing still another example of the rolling member on the slider side according to FIG. 8. FIG. 9 is a cross-sectional view showing still another example of the rolling member on the slider side according to FIG. 8. FIG. 9 is a cross-sectional view showing still another example of the rolling member on the slider side according to FIG. 8. It is sectional drawing which shows the rolling element rolling groove | channel on the slider side provided with a hook part. It is a schematic diagram which shows the apparatus structure for demonstrating a filament winding method. It is a schematic diagram explaining the winding method of the filament bundle in a filament winding method, The figure (a) is a figure which shows helical winding and the figure (b), respectively, parallel winding.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  In the present invention, the type of the uniaxial actuator is not limited, and the uniaxial actuator shown in FIG. 1 is illustrated here. As shown in the drawing, the guide rail 11 extending in the axial direction includes side walls 30 and 30 erected vertically from both sides of the belt-like bottom plate, and the cross section of the surface perpendicular to the axial direction is substantially concave. ing. A screw shaft 13 having a helical thread groove 13a on the outer peripheral surface is disposed at the center in the width direction inside the guide rail 11. The screw shaft 13 is supported by support units 17 and 17 attached to both ends of the guide rail 11 so as to be rotatable in both forward and reverse directions.

  A rectangular parallelepiped slider 12 is disposed inside the guide rail 11 and is screwed to the screw shaft 13 via a large number of rolling elements 14. A through hole through which the screw shaft 13 is inserted is provided at the center of the slider 12, and a screw groove 12 a that is spirally continuous is formed on the inner peripheral surface of the through hole. The thread groove 12a is opposed to the thread groove 13a of the screw shaft 13, and a large number of rolling elements 14 are loaded in the rolling element rolling path 21 formed by both the thread grooves 12a and 13a so as to be able to roll. ing. The slider 12 includes a slider main body 12A and end caps 12B and 12B that are detachably attached to both ends in the axial direction.

  In addition, rolling element rolling grooves 11 a and 11 a extending in the axial direction are formed on the opposing inner side surfaces of the side walls 30 and 30 of the guide rail 11. Further, rolling element rolling grooves 12b and 12b facing the rolling element rolling grooves 11a and 11a of the guide rail 11 are provided on both side surfaces of the slider 12, and the rolling element rolling grooves of the facing guide rail 11 are provided. 11a and the rolling element rolling groove 12b of the slider 12 form a rolling element rolling path. Further, inside the slider 12, rolling element return paths 16, 16 are formed which are parallel to the rolling element rolling path and penetrate in the axial direction. A rolling element circulation path is formed by the rolling element return path 16 and curved paths (not shown) continuously provided at both ends thereof, and a large number of rolling elements 15 are formed in the rolling element circulation path. It is loaded so that it can roll freely.

  Furthermore, the support units 17 and 17 are provided with through holes, and a rolling bearing (not shown) is fitted to the inner peripheral surface of the through holes. The screw shaft 13 is inserted and fitted into the inner diameter portion of the rolling bearing, and the screw shaft 13 can be rotated by the rolling bearing.

  In the uniaxial actuator configured as described above, when the screw shaft 13 is rotated, the slider 12 screwed into the shaft rotates along the guide rail 11 via the rolling of the rolling element 15 in the rolling element rolling path. Move smoothly in the direction. When the slider 12 moves, the rolling elements 15 in the rolling element rolling path circulate infinitely while rolling on the rolling element circulation path.

In the present invention, the guide rail 11 is made of metal to ensure mechanical strength equivalent to that of a conventional metal guide rail, and the filament winding described later is formed on the inner peripheral surface of the rolling element rolling groove 11a of the guide rail 11. A specific FRP rolling member 100 is joined by a method or a sheet winding method. Therefore, the metal material can be reduced by the amount of the rolling member 100, and the weight of the guide rail 11 can be reduced. Further, the rolling element 15 that rolls on the rolling element rolling groove 11a of the guide rail 11 is made of metal, and if the rolling element rolling groove 11a is made of metal, metal contact occurs, and peeling due to adhesion is likely to occur. By making the rolling member 100 made of a specific FRP, adhesion becomes difficult to occur because different materials come into contact with each other. Furthermore, the specific FRP forming the rolling member 100 has higher strength and excellent wear resistance than FRP in which reinforcing fibers are dispersed in a resin.

  FIG. 2 is a view showing an example of the rolling member 100, and shows one guide rail 11 in a cross section perpendicular to the axial direction. As shown in the drawing, the inner circumferential surface of the rolling element rolling groove of the guide rail 11 is scraped by the thickness of the rolling member 100, and the rolling member 100 is embedded therein and joined with an adhesive. By making the cross-sectional shape of the rolling member 100 into a V shape as shown in the figure, the rolling member 15 is in point contact with the rolling member 15, and the contact area can be minimized. Further, the contact angle α with the rolling element 15 is 45 ° ± 15 ° (30 to 60 °). By making the contact angle α within this range, the contact surface pressure between the rolling member 100 and the rolling element 15 can be kept stable. The rolling element rolling grooves are also formed in a V-shaped cross section in accordance with the rolling member 100.

  In FIG. 2, the rolling member 100 is an integrated object having a V-shaped cross section, but stress at the time of molding remains in the bent portion. Therefore, as shown in FIG. 3, the rolling member 100 can be configured by a plate-like upper rail 101 and a lower rail 102, respectively. At that time, as shown in the drawing, the side surface 102a of the lower rail 102 is brought into contact with the lower end 101a of the flat portion of the upper rail 101 and connected so as to exhibit a V-shaped cross section as a whole. Since the lower rail 102 is thermally expanded by the passage of the rolling elements 15 and presses the flat surface lower end 101a of the upper rail 101, the joining state of both the rails 101 and 102 is improved.

  Also, as shown in FIG. 4, a stepped recess 101b corresponding to the thickness of the lower rail 102 is formed at the lower end 101a of the flat portion of the upper rail 101, and the side surface 102a of the lower rail 102 is engaged with the stepped recess 101b. You may let them. As a result, the contact area of the upper rail 101 with the lower rail 102 increases, and the stepped upper surface 101c of the stepped recess 101b of the upper rail 101 presses the upper surface near the side surface 102a of the plate rail 102, so that the lower rail 102 The movement can be further suppressed.

  In order to further increase the contact area between the upper rail 101 and the lower rail 102, the number of stepped recesses can be increased as shown in FIGS. In FIG. 5, the side surface 102a of the lower rail 102 is processed into a stepped recess 102b that engages with the stepped recess 101b of the upper rail 101 shown in FIG. 4 from the plane, and both stepped recesses 101b and 102b are engaged. ing. Further, in FIG. 6, the stepped recess 101d of the upper rail 101 has two steps, and the lower rail 101 having the stepped recess 102b shown in FIG. 5 is engaged. In either case, both stepped recesses 101b, 101d, and 102b are pressed against each other, and the engagement of both rails 101 and 102 is stabilized.

  As shown in FIG. 2, the rolling member 100 is joined to the inner peripheral surface of the rolling element rolling groove of the guide rail 11. However, as shown in FIG. By forming hook portions 20 that extend from both ends of the rolling member 100 to both ends of the rolling member 100, the rolling member 100 can be prevented from being detached from the rolling element rolling groove. Although not shown, the upper rail 101 and the lower rail 102 shown in FIGS. 3 to 6 are used as the rolling member 100, and the end portions of the upper rail 101 and the lower rail 102 may be suppressed by the hook portion 20. it can.

  Although the above is a case where the rolling member 100 is joined to the inner peripheral surface of the rolling element rolling groove 11a of the guide rail 11, a similar rolling member is also provided on the inner peripheral surface of the rolling element rolling groove 12b of the slider 12. It is also possible to join them, thereby further reducing the weight of the uniaxial actuator as a whole while ensuring the mechanical strength of the slider 12.

  That is, FIG. 8 corresponds to FIG. 2, the rolling element rolling groove 12b of the slider 12 is processed into a V-shaped cross section, and the integrated rolling member 100 shown in FIG. Similar rolling members 200 can be joined. In addition, although illustration is abbreviate | omitted, the rolling member 200 and the rolling element 15 are also point-contacted by the contact angle of 45 degrees +/- 15 degrees similarly. Moreover, a rolling member can also be comprised with an upper rail and a lower rail. FIG. 9 corresponds to FIG. 3, but the side surface 202 a of the lower rail 202 is engaged with the flat surface lower end 201 a of the upper rail 201. 10 to 12 correspond to FIGS. 3 to 5, the stepped recesses 201 b and 201 d of the upper rail 201 can be engaged with the stepped recess 202 b of the lower rail 202.

  Further, as shown in FIG. 13, similarly to FIG. 7, hook portions 25 extending from both end edges of the rolling element rolling groove of the slider 12 to both ends of the rolling member 200 are formed to remove the rolling member 200. Separation can also be prevented.

  The rolling members 100 and 200 are FRP molded bodies obtained by binding reinforcing fibers with a binder resin. In the present invention, the base material produced by using the filament winding method or the sheet winding method is used as described above. Are formed into a V-shaped cross section, or press-molded into the upper rail 101 and the lower rail 102. By using the filament winding method or the sheet winding method, the strength and wear resistance of the fiber reinforced resin in which the reinforced fiber is dispersed in the resin are improved.

  FIG. 14 is a schematic diagram showing an apparatus configuration for explaining the filament winding method, in which a plurality of reinforcing fiber filaments are passed through a resin tank in which a liquid binder resin is stored and coated or impregnated with the binder resin. The reinforcing fiber filament bundle is wound around a rotating mandrel (core bar) at a predetermined angle. The reinforcing fiber filament bundle moves back and forth on the mandrel by a traverse device.

  As shown in FIG. 15 (a), the reinforcing fiber filament bundle is wound by helical winding wound so as to intersect at a certain angle (θ = 15 ° in the example in the figure) with respect to the lower layer filament bundle. As shown in FIG. 15 (b), it can be roughly divided into parallel windings that are wound so as to be perpendicular to the mandrel, but in terms of strength, helical windings are superior and are preferable. In addition, the crossing angle (θ) in helical winding is preferably 10 ° to 85 °, and particularly preferably 45 °.

  When the desired winding thickness is reached, the mandrel is removed from the apparatus, the binder resin is uncured or semi-cured, the mandrel is extracted, and the wound bundle of filament bundles after the mandrel is extracted is folded into a flat plate shape. Then, it is mounted on a press molding machine and heated and pressed to form a V-shaped cross section or plate. At that time, a release agent may be applied to the mandrel in advance in order to facilitate the extraction of the mandrel.

  The stepped recesses 101b and 101d of the upper rail 101 and the stepped recesses 102b of the lower rail 102 may be press-molded using a mold having these stepped recesses, or may be plate-shaped molded products. You may process into a step-shaped recessed part later.

  In the sheet winding method, although not shown in the drawings, a prepreg having a sheet shape is produced by knitting reinforcing fibers into a sheet shape and binding them with a binder resin. Then, a plurality of the prepregs are laminated to have a predetermined thickness, mounted on a press molding machine, and formed into a V-shaped cross section or a flat plate shape.

  Furthermore, a filament bundle wound by a filament winding method may be folded into a flat plate and a prepreg by a sheet winding method may be laminated and press-molded.

  The reinforcing fibers forming the filament bundle and the sheet are organic fibers or inorganic fibers having a tensile strength of 500 MPa or more, preferably 3920 MPa or more and a tensile elastic modulus of 30 GPa or more, preferably 235 GPa or more. Specific examples include the fibers shown in the following table. Among them, carbon fiber (CF) is preferable because it is lightweight and has high strength. The carbon fiber can be either PAN-based or pitch-based.

  Other preferable reinforcing fibers include glass fiber (GF), aramid fiber (AF), boron fiber (BF), polyarylate fiber (PARF), polyparaphenylene benzoxazole fiber (PBOF), ultrahigh molecular weight polyethylene fiber (UHPEF). And the like.

  The reinforcing fiber is preferably surface-treated with a sizing agent such as a urethane resin, an epoxy resin, an acrylic resin, or a bismaleimide resin in order to enhance the adhesion with the binder resin.

  The average diameter of the reinforcing fibers is preferably 5 to 21 μm, more preferably 7 to 15 μm. When the average diameter is smaller than 5 μm, the strength per one becomes low and stable production becomes difficult, and the cost is greatly increased, so the practicality is low. When the average diameter is thicker than 21 μm, the strength per one is increased, but the filament bundle becomes too thick and it is difficult to densely wind.

  Although there are short fibers and long fibers, long fibers are preferable because they are superior in strength, impact resistance, dimensional accuracy, conductivity, and the like as compared with short fibers.

  As the binder resin, an epoxy resin, a bismaleimide resin, a polyamide resin, a phenol resin, or the like can be used, and is selected in consideration of adhesiveness to the reinforcing fiber. For example, in the case of carbon fiber, an epoxy resin can be used. The amount of the binder resin applied or impregnated is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, and further preferably 24 to 33% by mass with respect to the total amount of the reinforcing fiber filament bundle or sheet. preferable. When the amount of the binder resin is less than 15% by mass, the binding of the filament bundle or the sheet is not sufficient, and when it exceeds 45% by mass, the amount of the reinforcing fibers is too small to obtain sufficient strength. The amount of the binder resin is the amount of resin in the obtained screw shaft, and the balance is the amount of reinforcing fibers or the total amount with the sizing agent.

  The present invention can be modified in various ways. For example, when the contact angle α between the rolling members 100 and 200 and the rolling element 15 is 45 ° ± 15 °, it is not necessary to have a V-shaped cross section as described above. The cross-sectional shape may be another cross-sectional shape such as a Gothic arch shape.

DESCRIPTION OF SYMBOLS 11 Guide rail 11a, 12b Rolling body rolling groove 12 Slider 13 Screw shaft 14, 15 Rolling body 17 Support unit 20, 25 Hook part 30 Side wall 100, 200 Rolling member 101, 201 Upper rail 102, 202 Lower rail 101b, 101d , 102b, 201a, 201d, 202b Stepped recess

Claims (5)

A cross-sectional substantially concave shape in which a rolling element rolling groove is formed in the axial direction on the inner side surface of each side wall, comprising a belt-like bottom plate extending in the axial direction and side walls vertically extending from both sides of the bottom plate. A guide rail, a screw shaft disposed in parallel to the axial direction inside the guide rail and having a helical thread groove on an outer peripheral surface, and a screw shaft attached to the guide rail and rotatably supporting the screw shaft. A support unit, a slider having a rolling element rolling groove facing the rolling element rolling groove of the guide rail, screwed to the screw shaft, the rolling element rolling groove of the guide rail facing the slider, and the slider A plurality of rolling elements interposed between the rolling elements, and the slider is movable in the axial direction along the guide rail via the rolling of the rolling elements. In the single axis actuator
At least one of the inner peripheral surface of the rolling element rolling groove of the guide rail and the inner peripheral surface of the rolling element rolling groove of the slider is formed of a reinforcing fiber filament bundle and a binder resin. A rolling member made of a molded body made of a filament sheet and a binder resin, or a laminated body of the layer made of the filament bundle and the sheet, and a molded body made of a binder resin is joined, and the rolling A uniaxial actuator, wherein a contact angle between a member and the rolling element is 45 ° ± 15 °. A plate-like upper rail joined to the inner peripheral surface on the upper side of the rolling element rolling groove and a plate-like lower surface joined to the inner peripheral surface on the lower side of the rolling element rolling groove. It is composed of rails and
The uniaxial actuator according to claim 1, wherein a side surface of the lower rail is in contact with a lower end of the flat portion of the upper rail and has a V-shaped cross section.   The uniaxial actuator according to claim 2, wherein a side surface of the lower rail is engaged with a stepped recess formed at a lower end of the flat portion of the upper rail.   The uniaxial actuator according to claim 2, wherein the upper rail and the lower rail have flat stepped portions on the lower side, and the stepped concave portions are engaged with each other.   The hook part extended to the said transfer member side is formed in the both ends edge of the said rolling element rolling groove of the said guide rail, or the both ends edge of the said rolling element rolling groove of the said slider. The uniaxial actuator of any one of 1-4.

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