JP2005351379A - Link operating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase operability and positioning accuracy by suppressing rattling at the revolute pair parts of link mechanisms and also facilitate a return to an origin position. <P>SOLUTION: This link operating device comprises three or more sets of link mechanisms 1 to 3 having four revolute pair parts 6a to 8a, 6b<SB>1</SB>, 6b<SB>2</SB>to 8b<SB>1</SB>, 8b<SB>2</SB>, and 6c to 8c formed by rotatably connecting end link members 1a to 3a and 1c to 3c to input/output members 4 and 5 disposed on input and output sides and rotatably connecting end link members 1a to 3a and 1c to 3c on the input side and output side to center link members 1b to 3b. The input side and the output side are geometrically identical to each other with respect to a cross section at the center part of the link mechanisms 1 to 3. A spherical structure 11 connecting an input member 4 to an output member 5 through one or more contact parts 14 is installed in the link mechanisms. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a link actuating device, and is used for, for example, a robot joint that performs high-speed and precise operations such as complicated processing and article handling in a three-dimensional space, a game joystick capable of two-dimensional operation, and the like. To a link actuating device.

  For example, the present applicant has previously proposed an apparatus having three sets of link mechanisms as a link actuating apparatus that performs complicated processing in a three-dimensional space and operations such as article handling at high speed and precision ( For example, see Patent Document 1).

In this link actuating device, the end link members are rotatably connected to the link hubs provided on the input member and the output member, and the end link members on the input side and the output side are connected to the central link member. 3 or more link mechanisms connected in a rotatable manner, the input side and the output side are geometrically identical with respect to the cross section at the center of each link mechanism, and the rotation of each link mechanism connected to the input member Among the paired portions, two or more sets of link mechanisms are provided with a stationary mechanism for stopping the output member at an arbitrary position at one or more rotating pairs of each pair. Each link mechanism constitutes a three-bar chain composed of four rotating pairs.
JP 2004-9276 A

  However, in this link actuating device, since the cross-sectional area of the central part of the link hub provided in each of the input member and the output member is small, the mounting space for the input / output member is small, and the inner space of the link mechanism is used. Thus, it is difficult to secure a space for installing a passage through which the control medium between the input member and the output member flows.

  In addition, since the actuator and rotation angle drive gear unit provided for angle control of the output member are installed so as to protrude outside the link hub of the rotation pair of the link mechanism, a wide installation space is secured on the input member. There is a need to.

  Further, since the actuator and the rotational angle drive gear unit described above are exposed to the external environment, a means for protecting them from the outside must be taken, and for this purpose, the outer shape of the apparatus becomes large.

  Therefore, in order to solve this problem, the applicant of the present invention can increase the outer diameter of the central portion of the link hub without enlarging the outer shape of the entire device, and can arrange a drive mechanism such as an actuator in a compact manner. Has previously been proposed (Japanese Patent Application No. 2003-40086).

  This link actuating device controls the rotational position of the end link member, but its control method is not disclosed, and the output side link hub with respect to the rotation angle input to the input side link hub No control means has been disclosed for determining the attitude of the input side link or for determining the rotation angle of the input side link hub in response to the attitude input to the output side link hub.

  Therefore, the present applicant, based on the above-mentioned proposal (Japanese Patent Application No. 2003-40086), obtains the attitude of the output-side link hub with respect to the rotation angle input to the input-side link hub, or the attitude to the output-side link hub. A link actuating device provided with a control means for obtaining the rotation angle of the input side link hub with respect to the input has been previously proposed (Japanese Patent Application No. 2003-287945).

  This link actuating device is provided with a rotation angle detecting means for measuring the rotation angle of the end link member, so that the attitude of the output side link hub can be controlled by reverse conversion according to a predetermined relational expression. An example of use as a joystick for a game capable of two-dimensional operation is disclosed, in which the attitude of the output side link hub can be detected by forward conversion using an expression.

  By the way, in the above-mentioned link actuator, by attaching a friction member to each rotation pair of the link mechanism, the input side end link member, the center link member or the output side end link member can be fixed at an arbitrary angular position. When a simple structure is used, there is a difference in the frictional resistance of each rotating pair. Therefore, when the link mechanism is operated manually, there will be a difference in operating resistance depending on the angular direction, which may deteriorate the manual operability. There is sex. Further, if friction members are provided at all the rotating pairs, the manual operation becomes heavy, and the operability is deteriorated also in this respect.

  On the other hand, in the case of a link mechanism having a rotating pair portion that is not provided with a friction member as described above, if there is a gap in the rotating pair portion, rattling occurs when the link mechanism is stationary, and the output side link It becomes difficult to position and stop the hub with high accuracy.

  In the link actuator disclosed in Japanese Patent Application No. 2003-287945, control by a servo motor is used as means for fixing the output side link hub to which the lever of the joystick is attached at an arbitrary angular position. The mechanism becomes large scale. In addition, when a link actuating device is applied to a joystick, the current situation is that it often requires a structure for returning the actuated link mechanism to the origin position.

  Accordingly, the present invention has been proposed in view of the above-described improvements, and its object is to suppress backlash at the rotating pair of the link mechanism, to improve operability and positioning accuracy, and to the origin position. It is an object of the present invention to provide a link actuating device that can easily achieve the recovery of the above.

  As a technical means for achieving the above-mentioned object, the present invention connects the end link members so as to be rotatable with respect to the input / output members respectively arranged on the input / output side. There are three or more sets of link mechanisms consisting of four rotating pairs that rotatably connect the end link members to the center link member, and the input and output sides of the cross section at the center of each link mechanism are geometrical. In the same link operating device, a structure in which the input member and the output member are connected via one or more contact portions is attached to the link mechanism.

  Here, each of the three or more sets of link mechanisms provided between the input and output has the same geometric shape, and the reason why the link mechanisms are set to three or more sets is to provide a two-degree-of-freedom mechanism. is there. Here, “the input side and the output side are geometrically identical with respect to the cross section at the center of the link mechanism” means that the input side and the output side are separated on the symmetry plane of the central link member. It means that the geometric shape on the output side is the same.

  Each link mechanism forms a three-bar chain composed of four rotating pairs. The end link members on the input side and the output side have a spherical link structure, and the spherical link centers in the three or more sets of link mechanisms coincide with each other, and the distances from the centers are also the same. The axis of the rotating pair that becomes the connecting portion between the end link member and the central link member may have a certain crossing angle or may be parallel. However, the shape of the central link member in the three or more sets of link mechanisms is geometrically the same.

  In the link actuating device according to the present invention, the structure in which the input member and the output member are connected to each other via one or more contact portions is attached to the link mechanism, thereby preventing rattling at the rotating pair portion of the link mechanism. Suppressing and improving the manual operability and positioning accuracy can be achieved.

  The structure in the above-described configuration is preferably a spherical structure that includes a pair of spherical members provided on each of the input member and the output member, and connects the input member and the output member with one contact portion. The spherical member may have a structure in which the spherical center is movable in the central axis direction of the input member and the output member, and the spherical center always coincides with the intersection of the central axis of the input member and the output member.

  The structure includes a pair of spherical members provided on each of the input member and the output member, and an intermediate member interposed between the pair of spherical members, and the input member and the output member are in contact with each other. A spherical structure connected by parts is also possible. The pair of spherical members may have a structure in which the respective spherical centers exist on the central axes of the input member and the output member. The spherical member preferably has a structure in which the center of each spherical surface is movable in the central axis direction of the input member and the output member. Further, the pair of spherical members may have a structure in which the respective spherical centers coincide with the link centers on the input side and the output side. By aligning the input and output link centers with the spherical center of each spherical member in this way, the distance between the spherical centers is constant regardless of the operating angle, eliminating the need for an axially variable structure and rigidity. Can be improved. The intermediate member can have a structure in which the axial length can be adjusted, or a structure in which a plurality of rolling elements that are in point contact with the spherical member are arranged in the circumferential direction.

  In the above-described configuration, a spherical member is rotatably mounted on one of the input member and the output member via a bearing, and the rotating member is fixed to the spherical member, whereby the rotating member is connected to the input side member or the output member. If the rotation is possible, a three-degree-of-freedom mechanism can be realized.

  Furthermore, in the above-described configuration, a structure including a preload applying unit that applies a preload to the contact portion is desirable. By applying this preload, it is possible to close the clearance at the rotating pair and improve the rigidity, assist the rigidity of the link mechanism, and increase the rigidity of the entire link operating device. As the preload applying means, a structure in which the preload is applied in the central axis direction of the input member or the output member, or a structure in which the preload is applied in the linear direction connecting the link centers on the input and output sides is possible. Thus, if a preload is applied to the contact portion of the spherical structure and the angle between the input member and the output member can be fixed by the frictional force of the contact portion, a static mechanism can be obtained.

  Further, as the preload applying means, a structure in which the input member or the output member is applied in a direction parallel to a straight line connecting the input and output side link centers within a plane including the intersection of the central axis of the input member or the output member and the input and output side link centers. Is possible.

  In addition, if the preload is applied as a structure that increases the preload as the operating angle of the link mechanism increases, and the link mechanism can return to the origin position, the origin return function can be added to the link mechanism.

  In addition, a structure in which a contact force is applied to the contact portion of the spherical structure with a preload applied to the spherical member by the preload applying means is possible. In addition, if the contact portion of the spherical structure is coated, the maintainability and durability can be improved. Furthermore, if the spherical structure is provided with an electromagnetic lock mechanism, the rigidity at rest can be improved and the angle can be firmly fixed.

  Further, it is desirable to provide a structure in which a part of the spherical structure interferes with other parts, and it is desirable to limit the operating angle with the interference structure with the other parts, and a structure in which a part of the spherical structure interferes with the other parts. The chamfering may be formed in a part of the spherical structure at a half of the maximum operating angle of the link mechanism.

  Furthermore, a structure in which a rotation transmission unit is provided on two or more input side end link members of the link mechanism, and the link mechanism is driven by an actuator via the rotation transmission unit, or two or more input side end units of the link mechanism A structure provided with a rotation angle detection mechanism for detecting the rotation angle of the link member is possible.

  According to the present invention, by attaching to the link mechanism a structure in which the input member and the output member are connected via one or more contact portions, it is possible to suppress backlash at the rotating pair portion of the link mechanism, Manual operability and positioning accuracy can be improved. That is, the operability is stable in all the angular directions of the link mechanism, and the operability is improved without variation in the operational resistance depending on the angular direction.

  The basic composition of the link actuator shown in FIG. 1 and FIG. 2 is shown. This link actuating device is used, for example, in a robot joint that performs high-speed and precise operations such as complex processing and article handling in a three-dimensional space, a three-dimensional game joystick that can be used for two-dimensional operations, and the like. A set of link mechanisms 1 to 3 is provided. Each of these three sets of link mechanisms 1 to 3 has the same geometric shape.

The basic configuration of the link actuating device shown in FIG. 1 is the same as that disclosed in Japanese Patent Application No. 2003-40086 previously proposed by the present applicant, and the input / output members 4 and 5 have through-holes 9, 10 is a link hub having a donut shape with a spherical outer shape. Each rotation pair section 6a~8a of the link mechanism _{1~3, 6b 1, 6b 2 ~8b} 1, 8b 2, 6c~8c is supported end links 1a to 3a, the 1c~3c in a cantilever structure It comprises.

On the other hand, the basic configuration of the link actuating device shown in FIG. 2 is the same as that disclosed in Japanese Patent Application No. 2003-388307 previously proposed by the present applicant, and the input / output members 4 and 5 have a disk shape. Each rotation pair section 6a~8a of the link mechanism _{1~3, 6b 1, 6b 2 ~8b} 1, 8b 2, 6c~8c may comprise a structure that both end supporting end links 1a to 3a, the 1c~3c To do.

As shown in FIGS. 1 and 2, each of the link mechanisms 1 to 3 is rotatably connected to the input side end link members 1 a to 3 a that are rotatably connected to the input member 4 and the output member 5. The output side end link members 1c to 3c and the both end link members 1a to 3a and 1c to 3c are rotatably connected to each other so as to connect the both end link members 1a to 3a and 1c to 3c to each other. is composed of a central link member 1b to 3b, form four rotating pair section _{6a~8a, 6b 1, 6b 2 ~8b} 1, 8b 2, a three-section chain structure consisting 6C～8c.

Each rotation pair section 6a~8a in the link mechanism 1-3 of FIG. 1 and FIG. _{2, 6b 1, 6b 2 ~8b} 1, 8b 2, 6c~8c incorporates a bearing structure. As a result, it is possible to reduce the rotational resistance by suppressing the frictional resistance at the connecting portion, and to ensure smooth power transmission and improve the durability. As the bearing structure, it is possible to use two radial ball bearings, angular ball bearings, roller bearings, slide bearings, or one double row angular ball bearing.

The end link members 1a to 3a and 1c to 3c have a spherical link structure, and the spherical link centers in the three sets of link mechanisms 1 to 3 coincide with each other, and the distances from the centers are also the same. End links 1a to 3a, each axis of 1c~3c and two rotating pair section 6b ₁ of the intermediate link member _{1b~3b, 6b 2 ~8b 1, 8b} 2 may be with a certain crossing angle, parallel It may be. However, the shapes of the central link members 1b to 3b in the three sets of link mechanisms 1 to 3 are geometrically the same.

  In the link mechanisms 1 to 3, the geometric shapes of the end link members 1a to 3a and 1c to 3c are equal on the input side and the output side, and the shapes of the central link members 1b to 3b are also on the input side and the output side. When equal, the angular positional relationship between the central link members 1b to 3b and the end link members 1a to 3a and 1c to 3c connected to the input / output members 4 and 5 is input to the symmetry plane of the central link members 1b to 3b. If the side and the output side are the same, the input member 4 and the input side end link members 1a to 3a and the output member 5 and the output side end link members 1c to 3c move in the same manner due to geometric symmetry, The input side and the output side have the same rotation angle and rotate at a constant speed. The plane of symmetry of the central link members 1b to 3b when rotating at a constant speed is referred to as a uniform speed bisector.

  For this reason, by arranging a plurality of link mechanisms 1 to 3 having the same geometric shape sharing the input / output members 4 and 5 on the circumference, the central link member 1b is a position where the plurality of link mechanisms 1 to 3 can move without contradiction. -3b is limited to the movement only on the uniform speed bisector, so that constant speed rotation can be obtained even if the input side and the output side take any operating angle.

  In the embodiment shown in FIGS. 3 to 13 described below, the case where the present invention is applied to the link actuating device having the basic configuration shown in FIG. 1 will be described. However, the present invention is not limited to this, and the basic configuration shown in FIG. Of course, the present invention can also be applied to other link actuating devices.

  [First embodiment]

  FIG. 3 shows a link actuating device in which one spherical structure 11 is attached to a link actuating device composed of link mechanisms 1 to 3 to apply force in the directions of the central axes F and G of the input / output members 4 and 5. Show. The spherical members 12 and 13 connected to the input member 4 and the output member 5 have a rod-like shape having a spherical contact portion 14 at the tip which is in spherical contact between the input member 4 and the output member 5. The center coincides with the intersection A of the central axes F and G of the input / output members 4 and 5. For simplification of the drawing, some of the link mechanisms 1 to 3 are omitted.

  The spherical members 12 and 13 are inserted through the through-holes 9 and 10 of the input / output members 4 and 5 through the sliding bearings 15 installed in the input / output members 4 and 5, and are connected to the input / output members 4 and 5. A structure movable along the central axis directions F and G is provided. Further, a screw member 16 is screwed into the opening end portions of the through holes 9 and 10 of the input / output members 4 and 5, and the end surfaces of the spherical members 12 and 13 are pushed from the outside of the input / output members 4 and 5 by the screw member 16. Thus, the spherical force is manually applied to the spherical contact portions 14 of the spherical members 12 and 13.

By applying a spherical force to the spherical contact portion 14 of the spherical members 12 and 13, the link mechanisms 1 to 3 can be fixed in an arbitrary posture by friction at the spherical contact portion 14. Thus, the clearances of the rotary pairs 6a to 8a, 6b ₁ , 6b _{2 to} 8b ₁ , 8b ₂ , and 6c to 8c of the link mechanisms 1 to 3 can be reduced, so that the backlash at rest can be reduced. Further, since the rigidity of the spherical contact portion 14 is high, the rigidity of the link mechanisms 1 to 3 itself is assisted, and the rigidity of the entire link operating device is improved. Further, by fixing the sliding positions of the spherical members 12 and 13 in the central axis directions F and G, the operating angle of the input / output members 4 and 5 can be fixed. By applying grease or coating to the spherical contact portion 14, it is possible to reduce frictional resistance when the link mechanisms 1 to 3 are moved.

  In this embodiment, spherical force is applied to the spherical contact portion 14 by manually pushing the screw member 16, but elastic members such as springs and rubber are provided in the through holes 9, 10 of the input / output members 4, 5. And a spherical force may be applied to the spherical contact portion 14 by its elastic force. Alternatively, an elastic member may be provided on one of the input / output members 4 and 5 and a spherical force may be applied to the spherical contact portion 14 from the other with a screw or the like.

  [Second Embodiment]

  In the case of using the spherical structure 11 in which the spherical center of the spherical contact portion 14 and the intersection A of the central axes F and G of the input / output members 4 and 5 coincide with each other as in the first embodiment described above, the link actuator Since the spherical structure 11 and the central link members 1b to 3b interfere with each other as the angle becomes higher (the operating angle of the output member 5 increases), it is conceivable that the operating range of the link operating device becomes narrower.

  FIG. 4 and FIG. 5 show a link actuator that improves this point. 4 shows the link operating device in an upright state, and FIG. 5 shows the link operating device tilted by 90 °. A spherical structure 21 is attached to a link actuating device composed of the link mechanisms 1 to 3 to provide a structure for applying force in the directions of the central axes F and G of the input / output members 4 and 5. The spherical structure 21 has two spherical members 22 provided on each of the input member 4 and the output member 5 and an intermediate member 23 positioned therebetween. For simplification of the drawing, some of the link mechanisms 1 to 3 are omitted.

  A mounting member 26 is fixed to the input / output members 4 and 5 at the opening ends of the through holes 9 and 10 facing each other with bolts or the like, and the spherical member 22 is connected to the mounting member 26 with the central axis of the input / output members 4 and 5. It is slidably mounted along F and G. The attachment member 26 can be provided integrally with the input / output members 4 and 5 by processing the through holes 9 and 10 of the input / output members 4 and 5. The spherical member 22 has an axial shape having a spherical contact portion 24 at the tip, and the outer diameter surface of the shaft-shaped portion and the outer diameter surface of the shim 27 pressed against the spherical member 22 are in contact with the mounting member 26. The input / output members 4 and 5 are slidable in the direction of the central axes F and G. Although the shim 27 and the spherical member 22 are separate members, they may be integrally formed.

  A compression spring 28 is interposed between the shim 27 and the mounting member 26, and a force is always applied to the spherical member 22 in a direction approaching along the central axes F and G of the input / output members 4 and 5. Has been. At this time, the spherical centers D and E of the spherical member 22 on the input side and the output side exist on the central axes F and G of the input / output members 4 and 5, respectively. The distance BD of the center D is equal to the distance CE of the link center C on the output side and the spherical center E of the spherical member 22. That is, the straight line I passing through the spherical centers D and E of the spherical member 22 exists on a plane composed of the intersection A of the central axes F and G of the input / output members 4 and 5 and the link centers B and C on the input / output side. It is parallel to a straight line H connecting the link centers B and C on the input / output side (see FIG. 5).

Here, the input side link center B refers to the input side end link members 1a to 3a and the rotation shafts of the rotation pair portions 6a to 8a of the input member 4, the input side end link members 1a to 3a and the center link member. It means the intersection with the rotation axis of the rotation pairs 6b _{1 to} 8b ₁ with 1b to 3b. Further, the output-side link center C refers to the output-side end link members 1c to 3c and the rotation shafts of the rotation pairs 6c to 8c of the output member 5, the output-side end link members 1c to 3c, and the center link member 1b. means the intersection of the rotation axis of the rotating pair section 6b ₂ ~8b ₂ of ～3B.

The spherical surface portion of the spherical member 22 forms a spherical contact portion 24 by making spherical contact with the intermediate member 23 having both spherical ends, and a spherical force is applied to the spherical contact portion 24 by the compression spring 28. Yes. For this reason, the link mechanisms 1 to 3 can be fixed in an arbitrary posture by the friction of the spherical contact portion 24, and the rotating pair portions 6 a to 8 a, 6 b ₁ , 6 b of the link mechanisms 1 to 3 can be fixed by this force. _Since the clearances of _{2 to} 8b ₁ , 8b ₂ , and 6c to 8c can be reduced, backlash at the time of operation and stationary can be reduced. Further, since the rigidity of the spherical contact portion 24 is high, the rigidity of the link mechanisms 1 to 3 itself is assisted, and the rigidity of the entire link operating device is improved. By applying grease or coating the spherical contact portion 24, it is possible to reduce frictional resistance when the link mechanisms 1 to 3 are moved.

  In this embodiment, the spherical force is applied to the spherical contact portion 24 by the compression spring 28. However, as in the first embodiment described above, the spherical force is manually applied to the spherical contact portion 24 by a screw or the like. You may do it. It is also possible to use an elastic member other than the compression spring 28. Further, a sliding bearing may be installed on the guide surface of the sliding portion of the spherical member 22 so that the sliding operation can be performed smoothly, or grease may be applied or coated.

  In the spherical structure 21 in this embodiment, the elastic force by the compression spring 28 acts in a direction in which the operating angle of the input / output members 4 and 5 increases, so that the link mechanisms 1 to 3 are stopped in order to make the link mechanisms 1 to 3 stationary. A frictional force that overcomes the force is required. Here, the distance BD between the link center B on the input side and the spherical center D of the spherical member 22 and the distance CE (offset amount) between the link center C on the output side and the spherical center E of the spherical member 22 are smaller. Since the force acting on the operating angle of the input / output members 4 and 5 is reduced, the distance BD between the link center B on the input side and the spherical center D of the spherical member 19, and the link center C on the output side and the spherical member 22. It is desirable that the distance CE of the spherical center E is smaller.

  [Third embodiment]

  In the second embodiment described above, the input side link center B and the spherical center D of the spherical member 22 on the input side do not coincide, and the link center C on the output side and the spherical center E of the spherical member 22 on the output side. Therefore, the spherical member 22 needs to be slidable with respect to the input / output members 4 and 5. Further, since the compression amount of the compression spring 28 varies depending on the postures of the link mechanisms 1 to 3, the spherical force of the spherical contact portion 24 also varies depending on the posture.

  FIGS. 6 to 8 show link actuating devices that improve this point. In these link actuating devices, the link center B on the input side and the spherical center D of the spherical member 32 on the input side are matched, and the link center C on the output side and the spherical center E of the spherical member 32 on the output side are matched. A spherical structure 31 for applying a force in the axial direction connecting the spherical centers B and C on the input / output side is provided. For simplification of the drawing, some of the link mechanisms 1 to 3 are omitted.

  In the embodiment of FIG. 6, a spherical structure 31 is provided in which a spherical member 32 is installed at the opening ends of the input / output members 4 and 5 facing each other through the through holes 9 and 10 and an intermediate member 33 is interposed therebetween. The intermediate member 33 is divided into an input-side intermediate member 33a and an output-side intermediate member 33b, which are connected by a bolt portion 33c of the input-side intermediate member 33a. This is adjustable. Both end surfaces of the intermediate member 33 have a spherical shape, and a spherical contact portion 34 is formed by spherical contact with the spherical member 32 on the input / output side.

For this reason, it is possible to apply a spherical force to the spherical contact portion 34 by incorporating into the link actuating device in a state where the intermediate member 33 is shortened and lengthening the intermediate member 33. As a result, the link mechanisms 1 to 3 can be fixed in an arbitrary posture by the friction of the spherical contact portion 34, and the rotating pair portions 6 a to 8 a, 6 b ₁ of the link mechanisms 1 to 3 can be fixed by this force. Since the clearances 6b _{2 to} 8b ₁ , 8b ₂ , and 6c to 8c can be reduced, backlash at the time of operation and stationary can be reduced. Moreover, since the rigidity of the spherical contact portion 34 is high, the rigidity of the link mechanisms 1 to 3 itself is assisted, and the rigidity of the entire link operating device is improved. In this spherical structure 31, the direction of the spherical force is always the axial direction connecting the spherical centers B and C on the input / output side.

  In addition, what is necessary is just to mount | wear with the nut 33d as a locking measure in the fastening part of the input side intermediate member 33a and the output side intermediate member 33b by the bolt part 33c. In addition to providing the spherical member 32 on the input / output side separately, the inner end surfaces of the input / output members 4 and 5 that are opposite to each other may have a spherical shape with the link centers B and C as the spherical centers.

  In the embodiment of FIG. 7, the spherical member 42 has a spherical structure 41 in which the operating range of the link operating device is widened by increasing the spherical radius. Note that the intermediate member 43 constituting the spherical structure 41 may have a structure in which the length of the intermediate member 43 can be varied, as in the embodiment of FIG. Other configurations and operations are the same as those in the embodiment of FIG.

  In the embodiment of FIGS. 8A and 8B, a spherical member 52 is installed at the opening end of the input / output members 4 and 5 facing the through holes 9 and 10, and an intermediate member 53 is interposed between the spherical members 52 and output. The spherical structure 51 is configured to apply a spherical force to the spherical contact portion 54 from the side. A rolling element 55 (steel ball in the drawing) is interposed between the intermediate member 53 and the spherical member 52 on the input / output side, and the rolling element 55 and the spherical surface of the spherical member 52 are in point contact.

A shaft-like portion of the pressing member 57 is inserted into the through holes 9 and 10 of the output member 5 via a sliding bearing 56 so as to be slidable in the direction of the central axis G of the output member 5. A gap is provided between the output spherical member 52 and the output member 5, and an intermediate member 53 is interposed between the spherical members 52 using this gap, so that the pressing member 57 is placed on the outer plane of the output member 5. By fixing with a bolt or the like, a force can be applied to the contact portion 54 between the rolling element 55 and the spherical member 52. Therefore, the link mechanisms 1 to 3 can be fixed in an arbitrary posture by the friction of the contact portion 54, and the rotation pairs 6 a to 8 a, 6 b ₁ , 6 b ₂ of the link mechanisms 1 to 3 can be fixed by this force. Since the clearances of ˜8b ₁ , 8b ₂ , 6c to 8c can be reduced, backlash during operation and stationary can be reduced. Moreover, since the rigidity of the contact part 54 is high, the rigidity of link mechanism 1-3 itself will be assisted, and the rigidity of the whole link actuating device will improve. By applying grease or coating the contact portion 54, the frictional resistance when moving the link mechanisms 1 to 3 can be reduced.

  [Fourth embodiment]

  The fourth embodiment shown in FIG. 9 has a structure in which a rotating plate 69 is installed on the output side in the embodiment of FIG. 7 and a rotating mechanism with three degrees of freedom is provided. Two angular ball bearings 66, 68 are installed on both ends of the through hole 10 of the output member 5 so as to face each other, and the axial portion of the spherical member 62 on the output side is connected to the angular ball bearings 66, 68. Inserted into the inner diameter. In addition, about the intermediate member 63, it is good also as a structure which can change the length similarly to embodiment of FIG. For simplification of the drawings, the link mechanisms 1 to 3 are omitted.

  As a procedure for assembling the spherical structure 61, first, the intermediate member 63 is disposed between the spherical members 62 on the input / output side in a contracted state, and the intermediate member 63 is extended to apply a spherical force to the spherical contact portion 64. To do. The spherical member 62 on the output side is in contact with the inner ring end surface of one angular ball bearing 66 located inside the output member 5 and is not in contact with the other portions.

  On the upper surface of the output member 5, the rotating member 69 is inserted into the shaft-like portion of the spherical member 62 on the output side and fixed with a nut 67. Since the rotating member 69 is in contact only with the inner ring end surface of the other angular ball bearing 68 located outside the output member 5, preload is applied to the angular ball bearings 66, 68 by tightening the nut 67.

As a result, the rotating member 69 rotates integrally with the output-side spherical member 62. Therefore, not only can the link mechanisms 1 to 3 be fixed in an arbitrary posture by the friction of the spherical contact portion 64, but also the degree of freedom in the rotational direction of the rotating member 69 can be fixed at an arbitrary position. Furthermore, each rotary pair section 6a~8a of the link mechanism 1-3 by this _{force, 6b 1, 6b 2 ~8b 1} , 8b 2, it is possible to pack a gap 6C～8c, rattling during operation and stationary Can be reduced. Further, since the rigidity of the spherical contact portion 64 is high, the rigidity of the link mechanisms 1 to 3 itself is assisted, and the rigidity of the entire link operating device is improved. By applying grease or coating to the spherical contact portion 64, it is possible to reduce frictional resistance when the link mechanisms 1 to 3 are moved.

  In this embodiment, the angular ball bearings 66 and 68 are installed back to back in order to give a degree of freedom of rotation, but other structures may be used as means for giving the degree of freedom of rotation. Further, as in this embodiment, if a shaft-like portion is provided on the output spherical member 62 and the bearings 66 and 68 are installed on the output member 5 so as to be rotatable, a three-degree-of-freedom mechanism having another structure is attached. can do.

  [Fifth embodiment]

  10 and 11 show the link actuator that returns to the origin (upright posture) when the hand is released even if the link actuator is tilted. FIG. 10 shows a state in which the link actuator is upright, and FIG. 11 shows a state in which the link actuator is tilted by 90 °. For simplification of the drawings, the link mechanisms 1 to 3 are omitted.

  A receiving member 76 having a spherical surface on a part of the inner diameter surface is attached with bolts or the like to the opening ends of the through holes 9 and 10 of the input / output members 4 and 5 facing each other, and the spherical member 72 is attached to each inner diameter portion. Is inserted, and a part of the spherical surface of the spherical member 72 comes into spherical contact with the receiving member 76, thereby forming a spherical contact portion 74. The spherical centers D and E of the spherical member 72 do not coincide with the link centers B and C on the input / output side. The spherical centers D and E of the spherical member 72 on the input side and the output side exist on the central axes F and G of the input / output members 4 and 5, respectively, and the link center B on the input side and the spherical center D of the spherical member 72. The distance BD is equal to the distance CE between the output-side link center C and the spherical center E of the spherical member 72.

  That is, the straight line I passing through the spherical centers D and E of the spherical member 72 exists on a plane formed by the intersection A of the central axes F and G of the input / output members 4 and 5 and the link centers B and C on the input / output side. It is parallel to a straight line H connecting the link centers B and C on the input / output side (see FIG. 11). An intermediate member 73 is interposed between the spherical members 72, and an axial portion of the spherical member 72 on the input side is slidably inserted into the intermediate member 73. A compression spring 77 is disposed in the intermediate member 73 along the axial direction, and a pressing member 75 is fixed to the tip of the spherical member 72 on the input side with a bolt or the like, whereby the intermediate member 73 and the spherical surface on the input side are fixed. A compressive force is applied between the members 72.

  Further, since the intermediate member 73 is fixed to the output-side spherical member 72 with a pin or a screw (not shown), when the compression spring 77 is compressed, a force acts in the direction of drawing between the spherical members 72. In other words, when the link actuating device is tilted, the compression spring 77 is compressed, so that a force acts in the direction of drawing on the input / output side, and the link actuating device attempts to return to the origin position (upright posture). In addition, what is necessary is just to select a spring so that the compression spring 77 may be in the compressed state also in the origin position (upright posture).

FIG. 12 is a detailed view of a portion J in FIG. The inner end surface of the inner diameter portion of the receiving member 76 on the input side or the output side is chamfered at an angle that is 1/2 of the maximum operating angle θ _max required for the link operating device, and the link operating device reaches the maximum operating angle θ _max . In this case, if the axial portion of the spherical member 72 is in contact with the chamfered portion L, it can be an angle limiting mechanism of the link actuating device.

FIG. 13 is a detailed view of a portion K in FIG. The spherical member 72 on the output side is chamfered at a half of the maximum operating angle θ _max required for the link actuator, and when the link actuator reaches the maximum operating angle θ _max , the receiving member 76 By making contact with the chamfered portion M, it can be an angle limiting mechanism of the link actuating device.

  Also in this embodiment, the frictional resistance when the link actuating device is moved can be reduced by applying grease or coating to the spherical contact portion 74. In addition, a sliding bearing may be installed on the guide surfaces of the sliding portions of the spherical member 72 and the intermediate member 73 on the input side so that the sliding operation can be performed smoothly, and grease or coating may be applied.

In the first to fifth embodiments described above, two or more input-side end link member 1a~3a of rotation pair portion _{6a~8a, 6b 1, 6b 2 ~8b} 1, 8b 2, 6c~ A rotation transmission unit may be provided in 8c, and the link actuating device may be driven by an actuator such as a rotation motor or a linear motion motor via the rotation transmission unit. Further, the input-side end link member 1a~3a the input member 4 of the rotation pair portion _{6a~8a, 6b 1, 6b 2 ~8b} 1, 8b 2, on the rotation axis of 6C～8c, the end link members 1a It is also possible to provide two or more rotation angle detection mechanisms capable of detecting the rotation angle of ˜3a and use it as a joystick. Further, if the spherical structure in the first to fifth embodiments is provided with an electromagnetic lock mechanism, the rigidity at rest can be improved, and a strong angle can be fixed.

It is a perspective view which shows the basic composition of the cantilever support type which comprised three sets of link mechanisms with the link action | operation apparatus which concerns on this invention. It is a perspective view which shows the basic composition of the both-ends support type which comprised three sets of link mechanisms with the link actuator which concerns on this invention. It is sectional drawing which shows 1st embodiment of this invention. It is sectional drawing which shows the state in which the link mechanism stood upright in 2nd embodiment of this invention. In 2nd embodiment of this invention, it is sectional drawing which shows the state in which the link mechanism inclined 90 degrees. It is sectional drawing which shows 3rd embodiment of this invention. In the modification of 3rd embodiment of this invention, it is a front view which shows the state in which a link mechanism inclines 90 degrees. In the modification of 3rd embodiment of this invention, (a) is sectional drawing which shows the state in which the link mechanism stood upright, (b) is a top view which shows an intermediate member. It is sectional drawing which shows the state in which the link mechanism stood upright in 4th embodiment of this invention. In 5th embodiment of this invention, it is sectional drawing which shows the state in which the link mechanism stood upright. In 5th embodiment of this invention, it is sectional drawing which shows the state in which the link mechanism inclined 90 degrees. It is an expanded sectional view which shows the J section of FIG. It is an expanded sectional view which shows the K section of FIG.

Explanation of symbols

1-3 linkage 1a~3a, 1c~3c end link member 1b~3b intermediate link member 4 input member 5 output member 6a~8a rotation pair portion _{6b 1, 6b 2 ~8b 1,} 8b 2 rotating pair section 6c~ 8c Rotating Pair 11 Structure (Spherical Structure)
12, 13 Spherical member 14 Contact part

Claims (24)

  Four end link members are rotatably connected to the input / output members respectively arranged on the input / output side, and each end link member on the input side and the output side is rotatably connected to the central link member. In a link actuating device having three or more sets of link mechanisms composed of two rotating pairs and having the input side and the output side geometrically identical with respect to the cross section at the center of each link mechanism, the input member and the output member A link actuating device characterized in that a structure body connected through one or more contact portions is attached to the link mechanism.   2. The link operation according to claim 1, wherein the structure includes a pair of spherical members provided on the input member and the output member, respectively, and is a spherical structure that connects the input member and the output member with one contact portion. apparatus.   The link actuating device according to claim 2, wherein the spherical member has a structure in which a spherical center thereof is movable in a central axis direction of the input member and the output member.   The link actuating device according to claim 3, wherein the spherical center has a structure that always coincides with the intersection of the central axes of the input member and the output member.   The structure includes a pair of spherical members provided on each of the input member and the output member, and an intermediate member interposed between the pair of spherical members, and the input member and the output member are connected to two contact portions. 2. The link actuating device according to claim 1, wherein the link actuating device is a spherical structure that is connected by the above.   The link actuating device according to claim 5, wherein each of the pair of spherical members has a structure in which the center of each spherical surface exists on a central axis of the input member and the output member.   The link actuating device according to claim 5 or 6, wherein the spherical member has a structure in which the center of each spherical surface is movable in the central axis direction of the input member and the output member.   The link actuating device according to claim 5 or 6, wherein each of the pair of spherical members has a structure in which each spherical center coincides with a link center on an input side and an output side.   The link actuating device according to claim 8, wherein the intermediate member has a structure capable of adjusting an axial length thereof.   The link actuating device according to claim 8, wherein the intermediate member has a structure in which a plurality of rolling elements in point contact with the spherical member are arranged in a circumferential direction.   A spherical member is rotatably mounted on one of the input member and the output member via a bearing, and the rotating member is fixed to the spherical member, whereby the rotating member is rotated with respect to the input side member or the output member. The link actuating device according to any one of claims 1 to 10, which is made possible.   The link actuating device according to any one of claims 1 to 11, further comprising a preload applying unit configured to apply a preload to the contact portion.   The link actuating device according to claim 12, wherein the preload applying means is configured to apply preload in the central axis direction of the input member or the output member.   The link actuating device according to claim 12, wherein the preload applying means is configured to apply preload in a linear direction connecting the link centers on the input and output sides.   The link actuating device according to any one of claims 12 to 14, wherein a preload is applied to the contact portion of the spherical structure, and an angle between the input member and the output member can be fixed by a frictional force of the contact portion.   The preload applying means is configured to apply in a direction parallel to a straight line connecting the input and output side link centers within a plane including the intersection of the central axis of the input member or the output member and the input and output side link centers. The link actuating device according to claim 12.   The link actuating device according to claim 16, wherein the preload applying means is configured to increase the preload as the operating angle of the link mechanism increases, and the link mechanism can be returned to the origin position.   The link actuating device according to any one of claims 12 to 17, wherein a contact force is applied to the contact portion of the spherical structure with a preload applied to the spherical member by the preload applying means.   The link actuating device according to any one of claims 1 to 18, wherein the contact portion of the spherical structure is coated.   The link actuating device according to any one of claims 1 to 19, wherein an electromagnetic lock mechanism is attached to the spherical structure.   21. The link actuating device according to any one of claims 1 to 20, wherein a part of the spherical structure has a structure that interferes with other parts, and an operating angle is limited by an interference structure with the other parts.   The link actuating device according to claim 21, wherein a chamfer is formed in a part of the spherical structure at a half of the maximum operating angle of the link mechanism as a structure in which a part of the spherical structure interferes with other parts.   The link operation according to any one of claims 1 to 22, wherein a rotation transmission unit is provided in two or more input side end link members of the link mechanism, and the link mechanism is driven by an actuator via the rotation transmission unit. apparatus.   The link actuating device according to any one of claims 1 to 22, further comprising a rotation angle detection mechanism that detects a rotation angle of two or more input side end link members of the link mechanism.

Images