Rotation device

In a rotation device using a hydraulic actuator, a rotation angle range is increased. A placement member rotatably coupled to a rotary member has a projecting part on an upper face. A hydraulic actuator is arranged on a projecting face of the projecting part; the actuator and the rotary member coupled with a wire material. The projecting part is formed such that it becomes higher from a leading edge on the side of the rotary member to an intermediate portion in the longitudinal direction, and becomes lower from the intermediate portion to a trailing edge. Thereby, when fluid is supplied to the actuator and shortens the actuator length, a tip of the actuator moves along the projecting face of the projecting part, and is located high, separated from the upper face of the placement member such that the rotation angle range of the rotary member becomes large.

TECHNICAL FIELD

The present invention relates to a rotation device for rotating a rotary member by an operation of an actuator, and more specifically, to a rotation device that increases a rotation angle range of the rotary member.

BACKGROUND ART

Conventionally, there exist rotation devices for rotating a rotary member using an actuator which operates by being supplied with fluid, such as air or liquid. The actuator applied to this kind of rotation device has a tube shape as a whole, and is often a type in which a dimension in a diameter direction perpendicular to the full length direction thereof is inflated by the supply of fluid (a type called a McKibben type or hydraulic type actuator).

FIGS. 10(a) and10(b) show a conventional common rotation device1. In the conventional rotation device1, a plate-shaped rotary member3is rotatably coupled to one end part2aof an elongated-plate-shaped placement member2(a rotation center is a rotation shaft9), and a tube-shaped, hydraulic type actuator4is arranged on an upper face2bof the placement member2. The actuator4is attached with a wire material5at a tip4athereof, and an end part5aof the wire material5is coupled to an upper face3aof the rotary member3via an anchor6. In addition, the actuator4connects with a hose7for fluid (for example, air) supply at a rear end4bthereof, and the hose7is fixed to the upper face2bof the placement member2by a fixing member8, thereby the actuator4is fixedly attached to the placement member2.

From a state ofFIG. 10(a), when the fluid is supplied to the actuator4through the hose7, the actuator4is inflated as shown inFIG. 10(b). Here, the full length of the actuator4parallel to the X-direction in this figure (the longitudinal direction of the placement member2) shrinks, and the radial dimension of the actuator4parallel to the Y-direction in this figure (the thickness direction of the placement member2) expands. Therefore, the actuator4pulls the rotary member3via the wire material5. The actuator4pulling the rotary member3rotates the rotary member3by an angle α from the state shown inFIG. 10(a) centering on the rotation shaft9.FIG. 10(b) shows a state in which the actuator4is inflated to the maximum extent, and in this state, it is assumed that the wire material5is in parallel to the X-direction.

Components equivalent to the rotation device1as shown inFIGS. 10(a) and10(b) described above are also disclosed in the following Patent documents 1 to 3.

REFERENCE DOCUMENT(S) OF RELATED ART

DISCLOSURE OF THE INVENTION

Problem(s) to Be Solved by the Invention

In the conventional rotation device1shown inFIGS. 10(a) and10(b), the posture of the wire material5is substantially parallel to the X-direction in these figures. Therefore, even if the wire material5is pulled in the arrow direction shown as the X-direction in the state ofFIG. 10(a), a force component in the Y-direction which is important to rotate the rotary member3centering on the rotation shaft9(a force component in the tangent direction of the rotary member3as a circle centering on the rotation shaft9) will not be large at a start timing of the rotation. For this reason, as shown inFIG. 10(a), when the rotary member3is first rotated from the posture of the horizontal state, there is a problem in which the rotation of the rotary member3is difficult to start smoothly.

The rotation device1described above may be applied to various uses. However, when applied to a fingertip part of a robot hand, there may be a case where a sufficient dimension in the X-direction ofFIGS. 10(a) and10(b) is unable to be secured, for example. If the dimension in the X-direction cannot fully be secured, a size of the actuator4adopted to the rotation device1must be small. Therefore, because the actuator4of a small size has a small operation range, there is a problem in which the rotation angle range of the rotary member3cannot be increased even if the actuator4is operated to the maximum extent.

Further, in the conventional rotation device1, the actuator4is attached to the placement member2so as to be aligned, by a part of the hose7(or the rear end4bof the actuator4, etc.) being fixed to the placement member2with the fixing member8. However, in the state of pulling the wire material5, as shown inFIG. 10(b), a stress against the pulling tends to concentrate near a fixing part7aof the hose7by the fixing member8. Therefore, by the stress being intensively applied repeatedly in connection with a use frequency, there is a problem in which the fixing part7aand its neighborhood deteriorate easily compared with other portions.

The present invention is made in view of the above problems to provide a rotation device in which a projecting part, on which an actuator is laid, is provided on a placement member, to direct a pulling angle of a rotary member upward to smooth a start of a rotation of the rotary member, as well as a rotation angle range of the rotary member can be increased and degradation due to the use can be reduced.

Means for Solving the Problems

In order to solve the above-described problems, according to an aspect of the present invention, a rotation device includes a tubular actuator that inflates in a diameter direction so that a full length is shortened by being supplied with fluid, a placement member on which the actuator is arranged and to which one end part side of the actuator is fixed, a rotary member rotatably coupled to the placement member at the other end part side of the actuator, and a wire material for connecting the other end part of the actuator with the rotary member. The placement member is provided with a projecting part on a surface where the actuator is arranged, and the actuator is arranged on a projecting face of the projecting part.

In the aspect of the present invention, because the projecting part is provided to the placement member and the actuator is arranged on the projecting face of the projecting part, the actuator pulls the rotary member via the wire material from a higher position compared with the related art. For this reason, when starting a rotation of the rotary member in a horizontal state, a force component important to rotate the rotary member can be made larger than the related art, and associated with this, the rotary member in the horizontal state can be raised and rotated smoothly.

Moreover, in the rotation device according to the aspect of the invention, the projecting face of the projecting part may have a slope face where a projecting dimension thereof is higher from the connecting side of the rotary member to an intermediate portion of the projecting part in a direction corresponding to the full length direction of the actuator.

In the aspect of the invention, at least a part of the projecting face of the projecting part is formed in the slope face, and an inclination of the projecting face is made such that the face becomes higher from the connecting side of the rotary member toward the intermediate portion of the projecting part. Therefore, the other end part of the actuator to which the wire material is attached moves up the slope face as the full length of the actuator becomes shorter with the fluid supply and thus, the position of the other end part becomes higher. For this reason, because the other end part of the actuator can be located at the same height as the related art when the fluid is not supplied, the rotary member can be made into the horizontal posture even if the wire material of the same length as the related art is used. On the other hand, when the position of the other end part of the actuator becomes higher as the fluid is supplied, the actuator will draw the rotary member nearer than the related art because of the condition where the actuator pulls the rotary member from obliquely upward. As a result, a rotation angle range can be increased.

Further, in the rotation device according to the aspect of the invention, the projecting face of the projecting part may have a slope face where a projecting dimension thereof is lower from the intermediate portion of the projecting part to the fixed side of the actuator in a direction corresponding to the full length direction of the actuator.

In the aspect of the invention, because the slope face that becomes lower from the intermediate portion of the projecting part to the fixed side of the actuator is formed on the projecting face of the projecting part, when the fluid is supplied to the actuator, the full length of the actuator will be shorter so that the other end side of the actuator to which the wire material is attached moves to the fixed side of the actuator. Therefore, the actuator will be in a posture such that the other end side thereof is raised along the slope face, and the fixed side thereof is lowered. The actuator pulls the wire material in the posture where the other end side to which the wire material is attached is raised; a resisting force against the pulling is also applied to the slope face of the projecting part. As a result, a stress which is concentrated on a fixed part of the actuator in the conventional actuator can also be distributed to the resisting force over the slope face and, thus, degradation of the fixed part of the actuator can be suppressed. In addition, because the posture of the actuator to which the fluid is supplied inclines, it can contribute more to the pulling of the rotary member, compared with a case where it is not inclined.

Further, in the rotation device according to the aspect of the invention, the projecting face of the projecting part may have a first slope face where a projecting dimension thereof is higher from the connecting side of the rotary member to the intermediate portion of the projecting part, and a second slope face where a projecting dimension thereof is lower from the intermediate portion to the fixed side of the actuator, in a direction corresponding to the full length direction of the actuator. The second slope face may be less slippery compared with the first slope.

In the aspect of the invention, the first slope face that becomes higher from the connecting side of the rotary member to the intermediate part of the projecting part, and the second slope face that becomes lower from the intermediate portion of the projecting part to the fixed side of the actuator, are formed on the projecting face of the projecting part. Therefore, the rotation angle range of the rotary member can be increased by the first slope, and the degradation of the fixed part of the actuator can be suppressed by the second slope. Moreover, because the second slope face is less slippery compared with the first slope face, the actuator in the posture where the other end to which the wire material is attached is raised can easily secure a state in which the actuator holds on the second slope face and, thus, the degradation of the fixed part of the actuator can be further suppressed.

Further, in the rotation device according to the aspect of the invention, the placement member may be arranged with another actuator in parallel with the actuator. A side face of the projecting part to which the other actuator opposes may be hollowed in a concave shape.

In the aspect of the invention, the side face of the projecting part is hollowed in the concave shape in such a case where the two or more actuators are arranged in parallel to each other to use the rotation device. Therefore, even when the fluid is supplied to the actuator(s) arranged to the side face of the projecting part to inflate the actuator, the inflated actuator will be fit in the concaved hollow part of the projecting part. Thereby, an interference of the actuators that are inflated by the fluid supply is further prevented even if the actuators are arranged with a shorter interval, compared with a case where each actuator is arranged on a flat plane. Therefore, the two or more actuators can be arranged compactly.

Effect of the Invention

In the aspect of the invention, the actuator is placed on the projecting part provided to the placement member. Therefore, the actuator can pull the rotary member from a higher position compared with the related art, and thus, it can smoothly rotate the rotary member in the horizontal state.

Further, in the aspect of the invention, the slope face which becomes higher from the connecting side of the rotary member to the intermediate portion of the projecting part is formed on the projecting face of the projecting part. Therefore, the rotation angle range of the rotary member by the operation of the actuator can be made larger than the related art.

Further in the aspect of the invention, the slope face which becomes lower from the intermediate portion of the projecting part to the fixed side of the actuator is formed on the projecting face of the projecting part. Therefore, it can contribute to that, when the actuator pulls the rotary member, the stress which is conventionally concentrated onto the fixed part of the actuator is distributed over the slope face that supports the actuator, the degradation of the fixed part of the actuator is suppressed, and the rotation angle range of the rotary member is increased.

In the aspect of the invention, the first slope face and the second slope face that incline in different directions are provided to the projecting part. Therefore, the rotation angle range of the rotary member can be increased by the first slope face and the second slope face, and the degradation of the fixed part of the actuator can be suppressed by the second slope face. In addition, because the second slope face is less slippery compared with the first slope face, it can further suppress the degradation of the fixed part of the actuator.

In the aspect of the invention, in the case in which the rotation device where the two or more actuators are arranged in parallel to each other is used, even if the actuators are arranged with shortened intervals, the interference of the actuators which are inflated by the fluid supply can be prevented and, thus, the two or more actuators can be arranged compactly.

DESCRIPTION OF NUMERALS

BEST MODE OF CARRYING OUT THE INVENTION

FIGS. 1(a) to (c) show a rotation device10according to an embodiment of the present invention. The rotation device10of this embodiment is equivalent in fundamental configuration to the conventional rotation device1shown inFIGS. 10(a) and10(b). However, it has a new component including a projecting part20provided on an upper face12bof a placement member12where an actuator14is arranged, and the actuator14placed on a projecting face20athat is an upper face of the projecting part20. By applying the new component, the rotation device10is characterized in that it enables a rotation of a rotary member13smoothly by being pulled by the actuator14and increases a rotation angle range. Note that each of X-direction, Y-direction, and Z-direction shown in each figure is a direction perpendicular to the others, and the respective directions are common in each figure.

In the rotation device10, the flat-plate-shaped rotary member13is rotatably coupled to one end part12aof the elongated-plate-shaped placement member12. Specifically, as shown inFIG. 1(a), the placement member12has a concave portion12cin the central part of the placement member12in the width direction (i.e., the short side direction, which corresponds to the Z-direction inFIG. 1(a)) on the side of the one end part12a. On the other hand, the rotary member13has a convex part13bon the side connecting to the placement member12. A rotation shaft19penetrating the both (the concave portion12cand the convex part13b) in a state in which the convex part13bis located inside the concave portion12cof the placement member12is fit. Thereby, the rotary member13is rotatable centering on the rotation shaft19. The placement member12and the rotary member13of this embodiment are made of a synthetic resin.

As shown inFIG. 1(b),FIG. 2(b) and the like, the placement member12is provided with the hill-shaped projecting part20on the upper face12b. The projecting part20has a first slope face20bfrom a hill-shaped peak part20dto the side of the rotary member13, and has a second slope face20cfrom a hill-shaped peak part20dto the opposite side from the rotary member13(refer toFIGS. 2(a) and (b)). The first slope face20bis formed in an upwardly convex, loosely curved surface extending in a direction corresponding to the longitudinal direction of the placement member12(the X-direction in these figures) so that the projecting dimension becomes higher from a leading edge20e, which is on the connecting side to the rotary member13, to the peak part20dcorresponding to an intermediate part of the projecting part20. The second slope face20cis formed in an upwardly convex, loosely curved surface extending in the X-direction in these figures so that the projecting dimension becomes lower from the peak part20dof the projecting part20to a trailing edge20fon the opposite side of the rotary member13.

Such first slope face20band second slope face20care combined to form a projecting face20awhich is the upper face where the actuator14is arranged. The surface of the second slope face20cis less slippery compared with the surface of the first slope face20b. In detail, the surface of the first slope face20bis finished in a fine, smooth surface where a surface roughness is small, and the second slope face20cis finished in a rough surface where the surface is made rough to have the surface roughness being large. Here, as the method of making the second slope face20cless slippery compared with the first slope face20b, it may be considered that the surface of each of the slope faces20band20cis finished equally, and a sheet with a large friction coefficient (for example, a rubber sheet) is applied only to the second slope face20c, or the like.

Further, in the projecting part20, in this embodiment, the projecting dimension of the peak part20d(dimension in the Y-direction which is the thickness direction of the placement member12shown inFIG. 2(b)) is set to a height H1, and a dimension from the trailing edge20fin the horizontal direction (X-direction) to the peak part20dis set to a length L2(the full length of the projecting part20in the X-direction is a length L1). The height H1and the length L1of the full length of the projecting part20are determined based on dimensions of the actuator14to be adopted. Each dimension (height H1, length L1) is determined, in a state in which near a rear end14bof the actuator14is aligned with the trailing edge20fof the projecting part20, a tip14aof the actuator14projects slightly from the leading edge20eof the projecting part20to locate in the upper face12bof the placement member12. The length L2which is a dimension from the trailing edge20fto the peak part20dis set to a dimension corresponding to a full length T2(refer toFIG. 3(b)) when the actuator14of this embodiment described later is inflated to the maximum extent (in this embodiment, L2=T2). Therefore, the tip14a, to which a wire material15of the actuator14is coupled, locates at the highest position from the upper face12bof the placement member12when the actuator14is inflated to the maximum extent.

In this embodiment, the projecting part20corresponding to a part of the placement member12is formed by piling up a putty-like hardening resin on the upper face12bof the placement member12. However, if the placement member12is made from the synthetic resin and formed by injection molding in a metallic mold, the placement member12and the projecting part20may be integrally formed by forming a portion corresponding to the projecting part20in the metallic mold.

FIGS. 3(a) and3(b), andFIGS. 4(a) and4(b) show the actuator14applied to the rotation device10of this embodiment. The actuator14is supplied with an operating fluid through a hose17connected therewith, and, in this embodiment, air is supplied as the fluid. An operating fluid source (air supply source) is connected to a non-illustrated end of the hose17.

As shown inFIGS. 4(a) and4(b), the actuator14is configured so that a bag body26is covered with a covering body25. The bag body26accommodated in an inner space25cof the covering body25is formed of a non-rubber material, and, in this embodiment, a material containing a polypropylene component which is a synthetic polymer compound through which the fluid does not pass is used. For the synthetic polymer compound having the characteristic of not passing the fluid, a material containing, as an component, at least one of polypropylene, VCM/PVC, Teflon®, polyester, polyamide, polyethylene, polyimide, polystyrene, polycarbonate and the like, is applicable to the material of the bag body26(it is also possible to make the components described above intermingled). In an environment where such a synthetic polymer compound cannot be used or an environment where it is not humid, other materials which do not pass the fluid are also applicable to the material of the bag body26.

As for the bag body26, an end part26bto which the hose17is connected is an opening end, and a tip part26aopposing to the opening end is a closed end. To fix the hose17at the end part26b, the end part26bis winded with a thread-like bundling material (not illustrated inFIGS. 4(a) and4(b)) in a state in which the hose17is inserted in the end part26b, the insertion range of the hose17is covered with a heat contraction tube28from the outside, and a predetermined amount of heat is added to the heat contraction tube28to shrink the tube.

On the other hand, the covering body25is formed in an elastic cylindrical shape having a size to cover the bag body26so as to expand and contract, and, in this embodiment, is knitted into a hollow tube by a cord knitting machine using a polyester multifilament yarn (275 decitex) which is a thread made of ester. When knitting, the stitches are made in rhombus (bias) shapes, and the long diagonal line direction of the rhombus (bias) is in agreement with the longitudinal direction of the covering body25(X-direction, corresponding to the full length direction of the actuator14) in a non-loaded state. Thus, the stitches are easy to expand and contract in a direction parallel to the Y-direction shown inFIG. 3(b), exert a necessary tensile force, and increase in a tightening force when it expands more.

Such a covering body25secures a flexibility to allow itself to expand and contract associated with the deformation of the bag body26; however, it generates, in a state in which it expands to the maximum extent, the tightening force which can resist and hold a pressing force generated by the bag body26being inflated. Such a predetermined tightening force can be obtained by knitting into the hollow tube using the polyester multifilament yarn.

In order to manufacture the actuator14using the bag body26and the covering body25described above, first, the bag body26in the state in which the hose17is fixed to the end part26bis covered with the cylindrical covering body25, then, one end part25bof the covering body25from which the hose17extends is winded with a thread-like bundling member27b, and the end part25bis then bundled and fixed with the heat contraction tube28that covers the end part26bof the bag body26. The covering body25is also winded with a thread-like bundling member27aat a tip part25athereof on the opposite end to close the tip part25a, thereby the actuator14is formed. Here, the tip part26aof the bag body26is made to be a free end without being fixed. Note that, other than the thread-like members, cable ties made of a synthetic resin, bundling metals, clamp members, string-like members and the like, are applicable to the bundling members27aand27b.

The formed actuator14is very flexible because the bag body26is thin (a thickness of one-sheet portion is 50 μm) when the fluid is not supplied, where a thickness of the actuator14itself is in agreement with a thickness of the covering body25. Therefore, when the actuator14is placed on the projecting part20of the placement member12described above, it deforms in a “He” shape of Japanese “hiragana” character (a chevron shape) conforming to the shape of the projecting face20aof the projecting part20(refer toFIG. 1(b)). When the fluid (air) is supplied to the actuator14through the hose17, the bag body26begins to inflate, and a diameter of the covering body25expands in a direction perpendicular to the X-direction, following the inflation. Here, because the bag body26is made of the non-rubber material, it can be inflated smoothly even if a supplying pressure of the fluid is low.

When the fluid supply is further continued, the actuator14eventually deforms into a state shown inFIG. 3(b) andFIG. 4(b), and the full length of the actuator14will be shortened to the dimension T2from a dimension T1in the state in which fluid is not supplied (T1>T2), and the diameter of the actuator will be larger to a dimension D2from a dimension D1in the state in which fluid is not supplied (D1<D2). A shrinkage ratio (a rate of the full length contracting from the dimension T1to the dimension T2) of the actuator14applied to this embodiment is about 40%. The dimensions T1and T2described above are a distance between the bundling members27aand27bof the actuator14, (the ends14aand14bof the actuator14are located outside of the bundling members27aand27b).

Next, a procedure for manufacturing the rotation device10by arranging the actuator14described above on the projecting face20aof the projecting part20of the placement member12is described. First, the wire material15is attached to the tip14a(corresponding to the other end part) of the actuator14in advance. The wire material15can be attached by winding it around the tip14aof the actuator14. However, if using a line material or the like as the wire material15, it is also possible to provide an anchor to an end part on the attaching side, to lead the anchor to the inside of the tip part25aof the covering body25shown inFIG. 4(a), and to fasten the anchor and the tip part25atogether with the thread-like bundling member27a. Here, a length of the wire material15used is set, in the state in which the actuator14is attached as shown inFIGS. 1(a) and1(b), to a dimension so that the rotary member13is in a horizontal state with respect to the placement member12.

Next, in the state in which the rear end14bof the actuator14in the X-direction (corresponding to the one end part) is positioned so as to align with the trailing edge20fof the projecting part20, the hose17extending from the rear end14bis fixed to the upper face12bof the placement member12by a fixing member18. The fixing member18is a thread-like member which is winded through two through-holes (not shown) formed in the placement member12to fix the hose17onto the placement member12, however such a fixing way may be replaced by other ways. For example, it may also be possible to apply a U-shaped clamp member as the fixing member18, and to hammer it so that both the ends of the clamp member are driven into the upper face12bof the placement member12to hold down the hose17, thereby fixing the actuator14.

Then, the end part15aof the wire material15extending from the tip14aof the actuator14is fixed to an anchor16that is attached in advance to a surface13aof the rotary member13, and the actuator14and the rotary member13are coupled via the wire material15, thereby the rotation device10is formed. The dimensions of the respective members12and13, the actuator14, and the wire material15which are used in the rotation device10of this embodiment are made the same as those of the respective members2and3, the actuator4, and the wire material5which are applied to the conventional rotation device1shown inFIGS. 10(a) and10(b). In addition, the positions of the anchor16and the tip14aof the actuator14when the fluid is not supplied are designed so that they are equivalent to those of the rotation device1. In addition, as for the actuator14, what is equivalent to the actuator4of the conventional rotation device1is used. However, only the fixed position of the hose17onto the placement member12on the side of the rear end14bof the actuator14is, in this embodiment, because the actuator14is placed on the projecting part20, located closer to the rotary member13compared with the fixed position in the conventional rotation device1.

Next, based onFIGS. 5(a) to (c), a state in which the fluid is supplied to the actuator14through the hose17to rotate the rotary member13is described. First, in the state in which the fluid is not supplied as shown inFIG. 5(a), the tip14aof the actuator14is located on the upper face12bof the placement member12so as to be offset from the projecting part20. Therefore, the wire material15is located at a height separated from the upper face12bof the placement member12by the thickness of the tip14aof the actuator14(i.e., by a distance h1) and, thus, it is in a posture parallel to the upper face12bof the placement member12. Note that such a state of the tip14aof the actuator14is equivalent to the state in which the fluid is not supplied in the conventional rotation device1shown inFIG. 10(a).

Next, as shown inFIG. 5(b), when the fluid supply to the actuator14is started, the actuator14is inflated to shorten its full length, however, because the rear end14bside is fixed to the placement member12by the fixing member18, the tip14amoves to the rear end14bside. When the tip14aof the actuator14moves to the rear end14bside, the tip14aslips in the white arrow direction inFIG. 5(b) so that it moves up the first slope face20bof the projecting part20. Therefore, the attachment side of the wire material15to the tip14awill be located at a distance h2which is larger than a distance h1ofFIG. 5(a), as a height from the upper face12bof the placement member12(h2>h1). For this reason, the actuator14will pull the rotary member13via the wire material15from a higher position compared with the related art to start the rotation of the rotary member13. Therefore, the rotation of the rotary member13can be started smoothly from the horizontal state shown inFIG. 5(a).

In other words, as for the wire material15, because the connecting side to the actuator14becomes high in the state shown inFIG. 5(b), a force component parallel to the Y-direction (Y-direction vector) is generated more than the conventional art in a tensile force associated with the wire material15, as well as a force component parallel to the X-direction (X-direction vector). Because this force component parallel to the Y-direction acts to rotate the rotary member13in the horizontal state, it is possible to rotate the rotary member13with a sufficient response. In addition, because the first slope face20bof the projecting part20is the smooth surface, the tip14aside of the actuator14can move smoothly on the first slope face20b.

FIG. 5(c) shows a state in which the fluid is further supplied to inflate the actuator14to the maximum extent from the state shown inFIG. 5(b). When the actuator14is inflated to the maximum extent, based on the relationship between the distance from the trailing edge20fof the peak part20dof the projecting part20(the length L2shown inFIG. 2(b)) and the full length T2of the actuator14when it is inflated to the maximum extent (refer toFIG. 3(b)) (L2=T2), the tip14aof the actuator14is located near the peak part20dof the projecting part20, and located at a height most separated from the upper face (12b) of the placement member12(the height from the upper face12bis a distance h3, where h3>h2). For this reason, the wire material15will be in a posture where it is inclined the most, and, in the state shown inFIG. 5(c), it is inclined by an angle γ with respect to the X-direction.

Therefore, if the length of the wire material15is set to “S,” a dimension of the wire material15parallel to the X-direction in the state shown inFIG. 5(c) will be S×cos γ, and compared with the case of the conventional art shown inFIG. 10(b), a dimension of the wire material15parallel to the X-direction will be shorter by S×(1−cos γ). As a result, because the actuator14is fixed to the placement member12at the rear end14bside, the rotary member13will be drawn toward the placement member12at least by a distance which is more by the distance of S×(1−cos γ) than that of the conventional art. Therefore, a rotation angle β of the rotary member13will be greater than the rotation angle α in the conventional rotation device1shown inFIG. 10(b) (i.e., β>α). For this reason, even when an actuator with a large operation length is hard to apply because a large dimension cannot be secured in the X-direction, the rotation device10of this embodiment has an advantage in which the rotation angle of the rotary member can be increased. When the state ofFIG. 5(c) is seen in detail, because the actuator14itself is also located on the second slope face20c, it will be in the inclined posture. Therefore, the dimension in the direction parallel to the X-direction in the inclined posture will be shorter than the full length T2when the actuator14is inflated to the maximum extent as shown inFIG. 3(b). Specifically, if the inclination angle of the actuator14with respect to the X-direction in the state shown inFIG. 5(c) is set to Λ, then a shortened dimension of the actuator14in the X-direction will be T2×(1−cos Λ). For this reason, the total of T2×(1−cos Λ) and S×(1−cos γ) which is the dimension of the wire material15described above relates to a difference of the rotation angle of the rotary member13with respect to the conventional rotation device1shown inFIG. 10(b), and, therefore, the second slope face20ccontributes to an increase of the rotation angle of the rotary member13.

Further, in the state shown inFIG. 5(c), the actuator14is located on the second slope face20c, and is difficult to slip on the second slope face20c. Therefore, the actuator14is in a state in which it is supported with a large gripping force, and the resisting force according to the pulling by the wire material15will be applied to the second slope face20cin the white arrow direction inFIG. 5(c). For this reason, compared with the case of the conventional art shown inFIG. 10(b), the stress concentrated on a fixing part17aof the hose17by the fixing member18which fixes the actuator14is distributed to the second slope face20cas the resisting force, and, therefore, degradation of the parts relating to the fixation of the actuator14can be suppressed.

Note that the rotation device10according to the present invention is not limited to the form described above, and various modified embodiments can be considered. For example, for the actuator14used in the rotation device10, it is possible to use components configured of various materials other than those types that are shown inFIGS. 3(a) and3(b) andFIGS. 4(a) and4(b). For example, an elastic material of rubber (a synthetic rubber, etc.) can be used for the bag body26, and a material of vinyl chloride can also be used for the bag body26. Further, if the rotary member13is desired to be positively made into the horizontal state when the fluid is not supplied, it can be considered that a biasing member for biasing the rotary member13in a direction opposite from the rotation direction of the rotary member13by the actuator14is attached to a surface opposite from the surface on which the actuator14is arranged so that the rotary member13and the placement member12are coupled. To such a biasing member, a belt-like rubber member (refer toFIG. 7(b) of Patent document 3, etc.) or a helical extension spring or the like can be applied.

FIG. 6shows a rotation device10′ of a modified embodiment. This modified embodiment is characterized in that the first slope face is not provided to a projecting part20′ which is to be provided in the upper face12b′of a placement member12′. For this reason, a tip14a′of an actuator14′ placed on the projecting part20′ is located at the projection height of the projecting part20′ even if the fluid is not supplied. Therefore, a rotary member13′ in the horizontal state can be pulled from further above and, thus, a rotation of the rotary member13′ can be started even more smoothly.

FIG. 7shows a hand device30using rotation devices40,60,70,80, and90according to a modified embodiment of the present invention. The hand device30is just configured such that first to fourth rotation devices40-80are arranged at positions corresponding to parts from an index finger to a pinky finger of a human hand, and a fifth rotation device90is arranged at a position of a thumb. The first to fourth rotation device40-80are just attached to an end face31aof a base member31located near the human's wrist, while the fifth rotation device90is attached to a supporting portion32fixed to the base member31. Because each of the rotation devices40-90fundamentally has a configuration equivalent to each other, a configuration of the modified embodiment is described, represented by the first rotation device40which corresponds to the index finger. InFIG. 7, in order to avoid that the figure becomes complicated, illustrations of the actuators, the wire materials and the like are omitted in the rotation devices60-90other than the first rotation device40.

In the first rotation device40, a first rotary member42is rotatably coupled to one end part41aside of a placement member41on which a first actuator46, a second actuator47, and a third actuator48are arranged in parallel to each other. In the first rotation device40, a second rotary member43is rotatably coupled to an end part42aof the first rotary member42, and the third rotary member44is rotatably coupled to an end part43aof the second rotary member43. In addition, in the first rotation device40, a projecting part45is provided in a central part of the placement member41in a width direction (the Z-direction inFIG. 7), the first actuator46is placed on the projecting part45, and the second actuator47and the third actuator48are arranged on an upper face41bof the placement member41, at both sides of the first actuator46, respectively.

The first actuator46is for a rotation of the first rotary member42, and is coupled to the first rotary member42by a first wire material51. Further, the second actuator47(corresponding to another actuator) is for a rotation of the second rotary member43, and is coupled to the second rotary member43by a second wire material52. Further, the third actuator48(corresponding to another actuator) is for a rotation of the third rotary member44, and is coupled to the third rotary member44by a third wire material53.

The projecting part45on which the first actuator46is placed is equivalent to the projecting part20shown inFIGS. 2(a) and2(b), and the like described above, regarding a projecting face45c(refer toFIGS. 8(a) and8(b)). However, shapes of side faces of the projecting part45, to which the second actuator47and the third actuator48oppose, are different from the projecting part20described above.

FIGS. 8(a) and8(b) are cross-sectional views taken along a line B-B inFIG. 7, where the projecting part45is made in a shape such that one side face45aand the other side face45bto which the second actuator47and the third actuator48oppose, respectively, are hollowed in concave shapes. As shown inFIG. 8(b), each of these side faces45aand45bis made in a circular curved concave face so that, when the second actuator47and the third actuator48are inflated to the maximum extent, the respective side faces45aand45bconform to the circular shapes of the respective actuators47and48, respectively. The projecting face45cof the projecting part45has a dimension of a height H10from the upper face41bof the placement member41, and this height H10is set greater than an outer diameter of each of the actuators47and48when the actuator is inflated to the maximum extent. Here, in order to increase a space efficiency for arranging each of the actuators47and48, each of the actuators47and48are arranged so that a curvature of the concave face of each of the side faces45aand45bcurved in the circular arc shape in the projecting part45is in agreement with a curvature corresponding to an outer diameter of each of the actuators47and48when the actuator is inflated to the maximum extent, respectively, and the center of the circular arc formed by the concave face of each of the side faces45aand45bis in agreement with the center of each of the actuators47and48when the actuator is inflated to the maximum extent, respectively. Thus, the height of the placement member41from the upper face41bcan be further reduced, thereby contributing to a reduction in the device structure.

In such a modified embodiment, as shown inFIG. 8(b), even if the fluid is supplied to each of the actuators46-48simultaneously, each of the actuators46-48can be prevented from being inflated while interfering with each other. Therefore, each of the actuators46-48can be arranged so as to be packed in the Z-direction, thereby this arrangement will be suitable when two or more actuators are arranged so as to be packed parallely in intervals. In the meantime, two actuators47and48are arranged on both sides of the projecting part45inFIG. 7, andFIGS. 8(a) and8(b). However, such a configuration having the hollowed side faces can be applied also to a case in which an actuator is arranged only to either one of the sides.

FIGS. 9(a) and9(b) show a rotation device100of another modified embodiment.FIGS. 9(a) and9(b) are cross-sectional views of the same part asFIG. 1(c), and it is characterized in that a projecting face120aof a projecting part120provided in an upper face112bof a placement member112is hollowed so as to be curved in a concave shape. A curvature of the curve of the projecting face120ais in agreement with a curvature corresponding to an outer diameter of an actuator114arranged on the projecting face120awhen the actuator is inflated to the maximum extent. Thereby, as shown inFIG. 9(a), in the state in which the fluid is not supplied to the actuator114, the actuator114can be inflated smoothly without being influenced by the curved projecting face120a. Further, when the actuator is inflated to the maximum extent, the actuator114will be in a state in which it just fits the projecting face120a, and, therefore, even when the actuator114is inflated, a stable placing state of the actuator114can be secured. Such a projecting face120ahollowed in the concave shape can be applied to both the first slope face20band the second slope face20cshown inFIGS. 2(a) and2(b). However, as especially shown inFIG. 9(b), in order to stabilize the actuator114in the inflated state, it will be suitable to hollow the second slope face20cso as to be curved in a concave shape. Of course, such a projecting face of this modified embodiment (the projecting surface hollowed so as to be curved in the concave shape) is applicable also to the projecting parts20′,40and the like of the modified embodiments shown inFIG. 6, andFIGS. 8(a) and8(b).

INDUSTRIAL APPLICABILITY

The rotation device of the present invention rotates the rotary member coupled to the placement member on which the hydraulic actuator is arranged, by an operation of the actuator, and is increased with the rotation angle range of the rotary member compared with the conventional rotation device. The rotation device of the present invention is applicable to various manufacturing equipments in factories (especially, handling devices) or the like, as well as applicable to a hand part of various robots for industrial use, welfare use or the like, and an artificial arm or the like.