JP6747076B2 - Uniaxial actuator - Google Patents

Description

The present invention relates to a uniaxial actuator having a linear motion guide bearing and a screw type feed device integrated with each other.

The uniaxial actuator has a concave cross section and a guide rail having rolling element rolling grooves extending in the axial direction on the inner surfaces facing each other, and a guide rail arranged substantially parallel to the axial direction at a substantially central portion in the width direction. The slider provided with a screw shaft provided, a rolling element rolling groove that opposes the rolling element rolling groove of the guide rail and screwed onto the screw shaft through a number of balls, and attached to both ends of the guide rail. Two support units that rotatably support the screw shaft. Then, when the screw shaft is rotated, the slider screwed to the screw shaft smoothly moves in the axial direction by rolling the ball.

Conventionally, in the uniaxial actuator, the guide rail, the screw shaft, the slider and the ball are made of metal, and thus have a high weight. Therefore, for example, in the case of a multi-axis configuration such as a robot, the load capacity of the motor increases and the size of the entire device increases. It is also attempted to reduce the weight by making a member from a lightweight metal or making a hole in the guide rail, but this may increase the material cost and reduce the strength.

Further, 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 one in which reinforcing fibers are dispersed in resin, and it is expected that the mechanical strength will be lower than that of a metal guide rail.

Therefore, an object of the present invention is to provide a uniaxial actuator that uses a metal guide rail to ensure mechanical strength equivalent to that of a conventional one and also achieves weight reduction.

In order to solve the above problems, the present invention provides the following uniaxial actuator.
(1) A cross-section having 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 inner side surfaces of the both side walls. A concave guide rail, a screw shaft provided inside the guide rail in parallel to the axial direction and having a spiral screw groove on the outer peripheral surface, and attached to the guide rail to rotate the screw shaft. A support unit that is supported on the guide rail, a rolling element rolling groove that opposes the rolling element rolling groove of the guide rail, and a slider that is screwed onto the screw shaft, and a rolling element rolling groove that opposes the slider. And a plurality of rolling elements rotatably interposed between the rolling element rolling groove of the slider and the rolling element rolling groove of the slider, wherein the slider axially extends along the guide rail through rolling of the rolling element. In a uniaxial actuator that can be moved to
On 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, a molded body made of a filament bundle of reinforcing fibers and a binder resin, A rolling member made of a molded body made of a sheet of filament and a binder resin, or a laminated body of a layer made of the filament bundle and the sheet and a binder resin is joined, and the rolling is made. A uniaxial actuator, wherein a contact angle between a member and the rolling element is 45°±15°.
(2) The rolling member is a plate-shaped upper rail that is joined to the upper inner peripheral surface of the rolling element rolling groove, and a plate that is joined to the lower inner circumferential surface of the rolling element rolling groove. It consists of a lower rail and
The uniaxial actuator according to (1) above, wherein a side surface of the lower rail is in contact with a lower end of a flat surface portion of the upper rail to have a V-shaped cross section.
(3) The uniaxial actuator according to (2), wherein the side surface of the lower rail is engaged with a stepped recess formed in the lower end of the flat portion of the upper rail.
(4) The uniaxial actuator according to the above (2), characterized in that the upper rail and the lower rail each have a stepped concave portion on a lower side of a plane portion, and the stepped concave portions are engaged with each other.
(5) Hook portions extending toward the transfer member are 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 the same mechanical strength as the conventional one, and is made of a specific FRP manufactured by the filament winding method or the sheet winding method by processing the rolling element rolling groove. Since the rolling members are joined, the metal material is reduced by the amount of processing, and the weight is reduced. Moreover, since the guide rail only needs to be formed with the rolling element rolling groove of the conventional metal guide rail, the existing metal guide rail can be used, and the cost is low. Further, the specific FRP is superior in mechanical strength and wear resistance to the FRP in which reinforcing fibers are dispersed in resin, and further, the specific FRP rolling member and rolling element are made of different materials. Since they come into contact with each other, they do not cause adhesion and can prevent peeling of the rolling element surface.

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 secured and the weight of the uniaxial actuator as a whole is further reduced. Can be planned.

It is a partially cutaway perspective view showing the overall 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 rolling element rolling groove periphery 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 another example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows another example of the rolling member by the side of a guide rail according to FIG. It is sectional drawing which shows 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. FIG. 6 is a cross-sectional view showing an example of a rolling member on the slider side, including the periphery of a rolling element rolling groove 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. It is sectional drawing which shows the further another example of the rolling member by the side of a slider according to FIG. It is sectional drawing which shows the further another example of the rolling member by the side of a slider according to FIG. It is sectional drawing which shows the further another example of the rolling member by the side of a slider according to FIG. It is sectional drawing which shows a rolling element rolling groove by the side of a slider 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 the filament winding method, FIG. 9A is a diagram showing helical winding, and FIG.

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 exemplified here. As shown in the figure, the guide rail 11 extending in the axial direction is provided with side walls 30 and 30 standing vertically from both sides of the strip-shaped bottom plate, and the cross section of the plane perpendicular to the axial direction has a substantially concave shape. ing. Further, a screw shaft 13 having a spiral thread groove 13a on the outer peripheral surface is arranged at the center in the width direction inside the guide rail 11. The screw shaft 13 is supported by support units 17, 17 attached to both ends of the guide rail 11 so as to be rotatable in both forward and reverse directions.

A slider 12 having a rectangular parallelepiped shape is arranged inside the guide rail 11, and is screwed to a screw shaft 13 via a large number of rolling elements 14. A through hole for inserting the screw shaft 13 is provided in the central portion of the slider 12, and a spirally continuous screw groove 12a is formed on the inner peripheral surface of the through hole. The thread groove 12a faces the thread groove 13a of the screw shaft 13, and a large number of rolling elements 14 are rotatably loaded in the rolling element rolling path 21 formed by the both thread grooves 12a and 13a. ing. The slider 12 is composed of a slider body 12A and end caps 12B and 12B detachably attached to both axial end portions thereof.

Rolling element rolling grooves 11a, 11a extending in the axial direction are formed on the inner surfaces of the guide rails 11 on the opposite sides of the side walls 30, 30. Further, rolling element rolling grooves 12b, 12b facing the rolling element rolling grooves 11a, 11a of the guide rail 11 are provided on both side surfaces of the slider 12, and the rolling element rolling grooves of the guide rail 11 facing each other are provided. 11 a and the rolling element rolling groove 12 b of the slider 12 form a rolling element rolling path. Further, inside the slider 12, rolling element return paths 16 and 16 which are parallel to the rolling element rolling paths and penetrate axially are formed. A rolling element circulation path is formed by the rolling element return path 16 and curved paths (not shown) that are continuously provided at both ends of the rolling element return path 16. It is loaded so that it can roll.

Further, through holes are provided in the support units 17 and 17, and a rolling bearing (not shown) is fitted to the inner peripheral surface of the through holes. Then, the screw shaft 13 is inserted and fitted in the inner diameter portion of the rolling bearing, and the screw shaft 13 is rotatable by the rolling bearing.

In the uniaxial actuator configured as described above, when the screw shaft 13 is rotated, the slider 12 that is screwed into the screw shaft 13 is rotated 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 in the rolling element circulation path and endlessly circulate.

In the present invention, the guide rail 11 is made of metal to ensure the mechanical strength equivalent to that of the conventional metal guide rail, and the filament winding described later is provided on the inner peripheral surface of the rolling element rolling groove 11a of the guide rail 11. The specific rolling member 100 made of FRP is joined by the method or the sheet winding method. Therefore, the metal material can be reduced by the amount corresponding to the rolling member 100, and the weight of the guide rail 11 can be reduced. Further, the rolling element 15 rolling in 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, it will be in metal contact and easily peeled off due to adhesion. When the rolling member 100 made of a specific FRP is used, different materials come into contact with each other, so that the adhesion hardly occurs. Further, the specific FRP forming the rolling member 100 has higher strength and is excellent in wear resistance as compared with the FRP in which the reinforcing fibers are dispersed in the 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 its axial direction. As shown in the figure, the inner peripheral surface of the rolling element rolling groove of the guide rail 11 is scraped off by the thickness of the rolling member 100, and the rolling member 100 is embedded therein and bonded with an adhesive. By making the cross-sectional shape of the rolling member 100 into a V shape as shown in the drawing, the rolling member 15 is in point contact with the rolling element 15 and the contact area can be minimized. The contact angle α with the rolling element 15 is 45°±15° (30 to 60°). By setting the contact angle α within this range, the contact surface pressure between the rolling member 100 and the rolling elements 15 can be stably maintained. The rolling element rolling groove is also formed to have a V-shaped cross-section in accordance with the rolling member 100.

In FIG. 2, the rolling member 100 is an integral member having a V-shaped cross section, but the stress during molding remains in the bent portion. Therefore, as shown in FIG. 3, the rolling member 100 may be composed of a plate-shaped upper rail 101 and a plate-shaped 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 is connected so as to exhibit a V-shaped cross section as a whole. The lower rail 102 thermally expands by passing the rolling elements 15 and presses the lower end 101a of the flat portion of the upper rail 101, so that the rails 101, 102 are joined together in a good condition.

Further, as shown in FIG. 4, a stepped recess 101b corresponding to the plate thickness of the lower rail 102 is formed at the lower end 101a of the flat surface 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 me. As a result, the contact area between the upper rail 101 and the lower rail 102 increases, and the step 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 to cause the lower rail 102 to move. The movement can be suppressed more.

In order to further increase the contact area between the upper rail 101 and the lower rail 102, as shown in FIGS. 5 and 6, the number of steps of the stepped recess can be increased. 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. 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, the two stepped recesses 101b, 101d, 102b press each other, and the engagement between the rails 101, 102 is stabilized.

Further, 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, but as shown in FIG. It is also possible to prevent the rolling member 100 from separating from the rolling element rolling groove by forming the hook portions 20 extending from both end edges of the rolling member to both ends of the rolling member 100. Although illustration is omitted, it is also possible to use the upper rail 101 and the lower rail 102 shown in FIGS. 3 to 6 as the rolling member 100 and hold the ends of the upper rail 101 and the lower rail 102 with the hook portion 20. it can.

The above is the 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, but a similar rolling member is also mounted to the inner peripheral surface of the rolling element rolling groove 12b of the slider 12. It is also possible to join the sliders, whereby the mechanical strength of the slider 12 can be ensured and the weight of the uniaxial actuator as a whole can be further reduced.

That is, FIG. 8 corresponds to FIG. 2, in which the rolling element rolling groove 12b of the slider 12 is machined into a V-shaped cross section, and the inner peripheral surface thereof has the integral rolling member 100 shown in FIG. Similar rolling members 200 can be joined. Although not shown, the rolling member 200 and the rolling element 15 similarly make point contact at a contact angle of 45°±15°. Further, the rolling member may be composed of an upper rail and a lower rail. 9 corresponds to FIG. 3, but the side surface 202a of the lower rail 202 is engaged with the lower end 201a of the plane portion of the upper rail 201. 10 to 12 correspond to FIGS. 3 to 5, the stepped recesses 201b and 201d of the upper rail 201 and the stepped recess 202b of the lower rail 202 can be engaged with each other.

Further, as shown in FIG. 13, similarly to FIG. 7, the hook portions 25 extending from both ends 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 molded articles made of FRP in which reinforcing fibers are bound with a binder resin. In the present invention, the base material produced by the filament winding method or sheet winding method of the FRP is as described above. And V-shaped in cross section, or press-formed on the upper rail 101 and the lower rail 102. By using the filament winding method or the sheet winding method, the strength and the abrasion resistance are higher than those of the fiber reinforced resin in which the reinforcing fibers are dispersed in the resin.

FIG. 14 is a schematic diagram showing an apparatus configuration for explaining the filament winding method. A plurality of reinforcing fiber filaments are passed through a resin tank in which a liquid binder resin is stored to apply or impregnate the binder resin. While being bundled into one filament bundle, this reinforcing fiber filament bundle is wound around a rotating mandrel (core rod) at a predetermined angle. The bundle of reinforcing fiber filaments moves back and forth on the mandrel by a traverse device.

As shown in FIG. 15(a), the winding method of the reinforcing fiber filament bundle is a helical winding in which the reinforcing fiber filament bundle is wound so as to intersect the lower layer filament bundle at a certain angle (θ=15° in the example of the figure). As shown in FIG. 15(b), it can be roughly classified into parallel winding wound so as to be perpendicular to the mandrel, but helical winding is superior in strength and is preferable. The crossing angle (θ) in the helical winding is preferably 10° to 85°, and particularly preferably 45°.

Then, when the desired winding thickness is reached, remove the mandrel from the device, remove the mandrel when the binder resin is in an uncured or semi-cured state, fold the wound filament bundle after removing the mandrel, and flatten it into a flat plate shape. Then, it is mounted in a press molding machine and heated and pressed to form a V-shaped section or a plate-shaped section. At that time, in order to facilitate pulling out of the mandrel, a release agent may be applied to the mandrel in advance.

The stepped recesses 101b and 101d of the upper rail 101 and the stepped recess 102b of the lower rail 102 may be press-molded using a mold having these stepped recesses, or a plate-shaped molded product. It may be processed into a stepped recess later.

In the sheet winding method, although not shown, reinforced fibers are knitted into a sheet and bound with a binder resin to produce a sheet-shaped prepreg. Then, a plurality of these prepregs are laminated to have a predetermined thickness, mounted on a press molding machine, and molded into a V-shaped cross section or a flat plate shape.

Further, a wound product of a filament bundle formed by the filament winding method may be folded into a flat plate, and a prepreg formed by the 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. Specifically, the fibers shown in the following table can be mentioned, but among them, carbon fiber (CF) is preferable because it is lightweight and has high strength. The carbon fiber may be either PAN type or pitch type.

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

It is also preferable that the reinforcing fiber is 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. If the average diameter is smaller than 5 μm, the strength per piece is low and stable production becomes difficult, resulting in a large increase in cost, which is not practical. If the average diameter is thicker than 21 μm, the strength per filament is increased, but the filament bundle becomes too thick, and it becomes difficult to perform dense winding.

Although fibers include short fibers and long fibers, long fibers are preferable because they are superior in strength, impact resistance, dimensional accuracy, conductivity, etc., to short fibers.

The binder resin may be an epoxy resin, a bismaleimide resin, a polyamide resin, a phenol resin, or the like, and is selected in consideration of the adhesiveness with the reinforcing fiber. For example, in the case of carbon fiber, epoxy resin can be used. Further, the coating or impregnation amount of the binder resin is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, and further preferably 24 to 33% by mass, based on the total amount of the reinforcing fiber filament bundle or sheet. preferable. If the binder resin amount is less than 15% by mass, the binding of the filament bundle or the sheet is not sufficient, and if it is more than 45% by mass, the reinforcing fiber amount is too small to obtain sufficient strength. The amount of 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, if the contact angle α between the rolling members 100 and 200 and the rolling elements 15 is 45°±15°, it is not necessary to have the V-shaped cross section as described above. The cross-sectional shape may be another cross-sectional shape such as a Gothic arch shape.

11 Guide rails 11a, 12b Rolling element rolling groove 12 Slider 13 Screw shaft 14, 15 Rolling element 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 strip-shaped bottom plate that extends in the axial direction and side walls that are vertically provided from both sides of the bottom plate. Rolling element rolling grooves are formed on the inner side surfaces of the both side walls in the axial direction. Guide rail, a screw shaft provided inside the guide rail in parallel to the axial direction and having a spiral thread groove on the outer peripheral surface, and attached to the guide rail to rotatably support the screw shaft. A slider that has a support unit, a rolling element rolling groove that opposes the rolling element rolling groove of the guide rail, and is screwed to the screw shaft, and a rolling element rolling groove that opposes the guide rail and the slider. A plurality of rolling elements that are rotatably interposed between the rolling elements and the rolling groove of the rolling element, and the slider is movable in the axial direction along the guide rail through the rolling of the rolling elements. In the one-axis actuator that was
On 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, a molded body made of a filament bundle of reinforcing fibers and a binder resin, A molded body made of a filament sheet and a binder resin, or a rolling member made of a molded body made of a laminate of the filament bundle and the sheet and a binder resin is joined,
The sheet is a prepreg in which a reinforcing fiber is knitted into a sheet shape and is bound with a binder resin into a sheet shape, and
A uniaxial actuator, wherein a contact angle between the rolling member and the rolling element is 45°±15°. The rolling member includes a plate-shaped upper rail joined to the inner peripheral surface on the upper side of the rolling element rolling groove, and a plate-shaped lower rail 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 a flat surface 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 in a lower end of a flat surface portion of the upper rail. 3. The uniaxial actuator according to claim 2, wherein the upper rail and the lower rail have stepped recesses on respective lower sides of the flat surface portions, and the stepped recesses are engaged with each other. The 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.

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