JP5139938B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator that utilizes a stretching force generated when an elastic contraction body is pressurized.

  In recent years, the demand for actuators has been diversified and sophisticated with the improvement in performance of various mechatronic devices in recent years. One of the measures is to respond to the increased output of the actuator, and the development of a strong and durable actuator is strongly desired.

  Conventionally, as this type of actuator, for example, there are the following. That is, in this conventional actuator, an elastic contraction body is constituted by a rubber inner cylinder and a braided structure externally fitted to the inner cylinder, and closure members are attached to both ends thereof. The elastic contraction body is fixed to the closing member by caulking a cylindrical clamp at two locations (see Patent Document 1).

Further, a skirt portion having a diameter increasing toward the one end portion side is formed at one end portion of the clamp. As a result, contact between the bulging elastic contraction body and the edge of the clamp is avoided, so that the elastic contraction body can be protected without causing damage.
Japanese Examined Patent Publication No. 6-56164

  Such an actuator is used by being incorporated in a frame of a robot hand having a gripping mechanism, for example. That is, a gripping operation is performed on the frame by supplying and discharging a working fluid (for example, water, air, oil, etc.) to the inner cylinder of the actuator and appropriately expanding and contracting the elastic contraction body.

  By the way, when fluid is supplied to the conventional actuator, the clamp is not only radially outward but also toward the other end side through the skirt portion of the clamp by an elastic contracting body that bulges. The pressing force also acts in the direction.

  However, the fixing means of caulking with a clamp in the conventional actuator is not always sufficient in strength. In particular, when the working fluid is a high-pressure fluid, it is impossible to maintain a good fixed state between the elastic contraction body and the closing metal fitting, so that the working fluid leaks to the outside. It had. In this case, it is possible to change the thickness and material of the clamp, but it is impossible to secure the thickness due to the specifications of the clamp that is fixed by caulking. Then, it is difficult to change the material.

  Further, in the above-described conventional apparatus, the elastic contractor and the closing member are fixed by caulking, but there is a manufacturing difficulty that a dedicated tool and a die are required for the caulking work.

  Further, once the clamps are caulked and fixed in this manner, it is almost impossible to disassemble them, and there is a drawback that maintenance performance such as maintenance and inspection is lacking.

  On the other hand, it is possible to use a detachable hose band as a fixing means between the elastic contraction body and the closing member, but since there is a certain limit to the fastening force, a recent demand for higher output is required. It is not something that can be met.

  Therefore, the present invention has been made in view of such a point, and an object thereof is to provide an actuator that can sufficiently cope with an increase in output.

An actuator according to the present invention includes a cylindrical elastic body to which working fluid is supplied and discharged, an elastic contraction body having a net-like body that is externally fitted to the elastic body, and one end portion at both ends of the elastic contraction body. A terminal member provided with a plurality of stepped portions that are inserted and formed on the outer peripheral surface of the one end portion side so as to increase in diameter toward the other end portion, and restricts the outward expansion of the elastic contraction body In order to do so, a protective member fixed to the stepped portion of the terminal member via the elastic contraction body, and a restricting means for restricting the protective member from moving to the other end side of the terminal member are provided. It is a thing.

  According to this, when the high-pressure working fluid flows into the actuator, the elastic contraction body swells in the radially outward direction. Due to the bulging of the elastic contraction body, the protective member receives a pressing force in the tube axis direction not only in the radially outward direction but also toward the other end side of the terminal member. However, even if the pressing force in the tube axis direction is received, the protective member does not move to the other end side of the terminal member by the restricting means. Thereby, since the fixed state of the protection member and the terminal member is favorably maintained via the elastic contraction body, the working fluid does not leak. That is, such an actuator has a strength that can sufficiently withstand a large output of various devices to which the actuator is applied.

  Further, the restricting means may be constituted by a stopper provided on the terminal member so as to hold the end surface of the protection member located on the other end side of the terminal member.

  In this case, since the end surface of the protection member located on the other end side of the terminal member is held by the stopper, the protection member does not move to the other end side of the terminal member. Thereby, the fixed state of the protection member and the terminal member via the elastic contraction body is favorably maintained. Therefore, the working fluid does not leak, and it is possible to sufficiently meet the demand for higher output.

An actuator according to the present invention includes a cylindrical elastic body to which working fluid is supplied and discharged, an elastic contraction body having a net-like body that is externally fitted to the elastic body, and one end portion at both ends of the elastic contraction body. A terminal member to be inserted; a protection member fixed to one end of the terminal member through the elastic contraction body in order to restrict bulging of the elastic contraction body in a radially outward direction; and the protection Restricting means for restricting the member from moving to the other end side of the terminal member, and the restricting means holds the end surface of the protection member located on the other end side of the terminal member. The stopper is provided on the inner peripheral surface of the stopper, and a screw portion that can be screwed into a screw portion formed on the outer peripheral surface of the other end portion of the terminal member is provided.

  According to this, if the screw part of a stopper is screwed together with the screw part of a terminal member, the end surface of the said protection member will be hold | maintained by a stopper. Therefore, the protection member is restricted from moving toward the other end of the terminal member. Thereby, the fixed state of the protection member and the terminal member via the elastic contraction body is maintained well, and the working fluid does not leak. As a result, it is possible to sufficiently meet the demand for higher output.

  Further, the restricting means may be configured by a stopper provided on the elastic contraction body so as to hold the end face of the protection member located on the other end side of the terminal member.

  Also in this case, the movement of the protective member is restricted by the stopper, and a good fixed state can be maintained. Therefore, it is provided with a strength that can sufficiently meet the demand for higher output.

An actuator according to the present invention includes a cylindrical elastic body to which working fluid is supplied and discharged, an elastic contraction body having a net-like body that is externally fitted to the elastic body, and one end portion at both ends of the elastic contraction body. A terminal member to be inserted; a protection member fixed to one end of the terminal member through the elastic contraction body in order to restrict bulging of the elastic contraction body in a radially outward direction; and the protection A restricting means for restricting the member from moving to the other end portion side of the terminal member, and the restricting means is adapted to hold the end surface of the protection member located on the other end side of the terminal member so as to hold the elastic contraction. A stopper provided on the body, wherein a concave groove is formed on the outer peripheral surface of the terminal member, and a convex portion is formed on the inner peripheral surface of the stopper, and the elastic contraction body is pressed by the convex portion to cause the concave It is the one that was engaged in the groove.

  According to this, since the elastic contraction body pressed by the convex part of the stopper is engaged with the concave groove of the terminal member, the terminal member and the elastic contraction body are firmly fixed. Also in this case, since the movement of the protective member is restricted by the stopper, the fixed state between the protective member and the terminal member is maintained well. Therefore, the working fluid does not leak, and it is possible to sufficiently meet the demand for higher output.

  The protective member may be detachably provided on the elastic contraction body.

  If it does in this way, a protection member etc. will be removed from an elastic contraction body as needed, and it will become possible to assemble it further. For this reason, maintenance, inspection, etc. can be easily performed, and good maintainability can be secured.

  Further, the protective member and the stopper can be detachably provided on the elastic contraction body.

  Also in this case, the protective member and the stopper can be detached from the elastic contraction body and disassembled, and can be assembled, thereby providing good maintainability. In addition, if a hose band, for example, is used as a protective member or stopper fixing means, a special tool or mold is not required, and no special technique is required. It is possible to perform reliably.

  Furthermore, the actuator according to the present invention has an advantage that the entire configuration is very simple, and thus the actuator can be manufactured inexpensively and easily.

  As described above, according to the present invention, it is possible to obtain a strong and easy-to-handle actuator that can sufficiently meet the demand for higher output.

  Hereinafter, an embodiment of an actuator according to the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows an actuator according to the present embodiment, where FIG. 1 (a) is a front view and FIG. 1 (b) is a cross-sectional view. As shown in the figure, the elastic contraction body 1 at the center includes a cylindrical elastic body 2 made of rubber or the like, and a cylindrical net 3 that is externally fitted to the elastic body 2. The net-like body 3 is formed, for example, by weaving polyester fibers, ultra-high strength polyethylene fibers or the like in a lattice shape.

  One end side of the metal terminal member 4 is inserted into both ends of the elastic contraction body 1 so as to supply and discharge a fluid such as hydraulic oil. A through hole 5 is provided in the central portion of the terminal member 4 in the tube axis direction. Further, a plurality of step portions 15 formed so as to increase in diameter toward the other end portion side are provided in the circumferential direction with a predetermined interval in the tube axis direction on the outer peripheral surface on the one end portion side. Further, a concave groove 6 having a predetermined width in the tube axis direction is formed in a substantially central portion of the outer peripheral surface of the terminal member 4. Further, an annular convex portion 7 is provided projecting radially in the outer position of the concave groove 6. Furthermore, a screw portion 8 is provided on the outer peripheral surface of the terminal member 4 on the other end side located outside the convex portion 7.

  In order to restrict the outward expansion of the elastic contraction body 1, a metal protection member 9 is fitted on the elastic contraction body 1. This protective member 9 is composed of a pair of halves 9a, 9a, and is a plurality of detachable hose bands 10, and the step portion 15 of the terminal member 4 (on one end side of the terminal member 4) via the elastic contraction body 1. ). Further, a skirt portion 9b whose diameter increases toward the one end portion side is formed at one end portion of the protective member 9 (the central side of the elastic contraction body 1).

  Both ends of the elastic contraction body 1 are fixed to the outside of the convex portion 7 of the terminal member 4 by a fixing ring 11 so as to be folded back. The fixing ring 11 is made of, for example, a split ring or a C ring, and can be attached to and detached from the terminal member 4. Moreover, the substantially cylindrical stopper 12 has an inward convex portion 14 in which a screw portion 13 is formed on the inner peripheral surface. When the screw portion 13 is screwed into the screw portion 8 of the terminal member 4, the end portion of the elastic contraction body 1 and the fixing ring 11 are connected to the inward convex portion 14 of the stopper 12 and the convex portion 7 of the terminal member 4. It is fixed while being sandwiched between them. Thereby, the elastic contraction body 1 and the terminal member 4 are doubly fixed together with the fixing by the protection member 9.

  In this state, the front end surface 12a of the stopper 12 is set so as to be in contact with and held by the other end surface 9c of the protective member 9, and the stopper 12 side of the protective member 9 (the other end portion of the terminal member 4). Movement to the side) will be restricted. In addition, since the elastic contraction body 1 consists of the elastic body 2 having elasticity and the net-like body 3 knitted with predetermined fibers, when the stopper 12 is screwed, there is a slight dimensional error or assembly error. However, the front end surface 12a of the stopper 12 and the other end surface 9c of the protection member 9 can be reliably abutted and held while eliminating this.

  Note that the actuator according to the present embodiment does not use any means of caulking as a means for fixing each member, and therefore has excellent maintainability that allows for subsequent disassembly and assembly. Further, such disassembly and assembly operations not only require a special tool and mold, but also do not require any special technique, so that there is an advantage that a series of operations can be performed easily and reliably.

  The actuator according to the present embodiment is configured as described above. Next, a usage example in which the actuator is applied to a robot hand will be described.

  As shown in FIG. 2, the robot hand A includes gripping devices 20 and 21 and a plate-like base 22 to which the gripping devices 20 and 21 are fixed. The gripping devices 20 and 21 supply and discharge a fluid such as hydraulic fluid to and from a frame 23 having a gripping mechanism, a plurality of actuators 24 mounted on the frame 23 in the vertical direction, and a hose 25. Pressure adjusting device 26.

  The pair of gripping devices 20 are arranged side by side on the base 22 with a predetermined interval. The other gripping device 21 is fixed on the base 22 so as to face a space formed between the pair of gripping devices 20. Since the gripping devices 20 and 21 have substantially the same configuration except that the number of actuators 24 to be used is different, only the former gripping device 20 will be described here.

  The frame 23 includes a bottom plate 27 fixed to the base 22, a top plate 28 disposed opposite to the bottom plate 27, and a pair of side plates 27, 28 connected to the side surfaces of the frame 23. Links 29 and 29 are provided. The link 29 has a plurality of linkages 30 rotatably connected via pins 31. The pins 31 are formed to have a predetermined length so as to connect the pair of links 29 and 29 together. . Further, a substantially U-shaped cover body 32 is disposed on the front side of the frame 23. This restricts the movement of the actuator 24 toward the front side of the elastic contraction body 1 within a predetermined range, and both ends of the cover body 32 are connected to the linkages 30, 30 facing the links 29, 29. It is fixed to the side center. Further, a regulating plate 33 is provided on the back surface of the predetermined linkage 30 to engage with the back surface of the upper or lower linkage 30 connected thereto and regulate the rotation to the back side.

  A plurality of actuators 24 are fixed between the top plate 28 and the bottom plate 27, and the terminal member 8 located at the upper end of the actuator 24 is closed by a plug 34. On the other hand, the terminal member 8 located at the lower end is connected to the pressure adjusting device 26 via the hose 25. The robot hand A according to the present embodiment is configured as described above.

  Next, the case where the rod-like body 50 is fixed on the base 22 as shown in FIG. In this case, a substantially semicircular concave groove 22a into which the rod-like body 50 can be fitted may be formed on the base 22 as shown in FIG. In this state, the working fluid is not yet supplied to the actuator 24, and the gripping devices 20 and 21 are in an upright state.

  First, the rod-shaped body 50 is fitted into the concave groove 22a of the base 22 and placed. Thereafter, the working fluid pressurized from each pressure adjusting device 26 via the hose 25 is supplied to the actuator 24 of each gripping device 20, 21. As a result, the elastic body 2 of the actuator 24 bulges in the radially outward direction, and the mesh body 3 expands in the radially outward direction, while contracting in the tube axis direction.

  Further, due to the bulging of the elastic contraction body 1, a pressing force acts on the protective member 9 in the tube axis direction toward the outside (the other end side of the terminal member 4) via the skirt 9 b. Such a pressing force increases as the working fluid becomes higher in pressure. However, since the other end surface 9c of the protection member 9 is held in contact with the tip end surface 12a of the stopper 12, the outward movement of the protection member 9 is restricted. Accordingly, the fixed state of the elastic contraction body 1 and the terminal member 4 by the protection member 9 is firmly maintained, so that the working fluid does not leak to the outside.

  On the other hand, in this case, the elastic contraction body 1 contracts in the tube axis direction. Due to the contraction of the elastic contraction body 1, each gripping device 20, 21 rotates toward the rod-shaped body 50 side as shown in FIG. 3B and curves so as to grip the outer peripheral surface of the rod-shaped body 50. . Thereby, the rod-shaped body 50 is firmly and securely fixed on the base 22. The rod-shaped body 50 is conveyed to another place in this state, for example.

  Further, when releasing the gripping state of the rod-shaped body 50 by the gripping devices 20 and 21, the working fluid in the elastic body 2 of the actuator 24 is discharged to the outside by the pressure adjusting device 26. Thereby, the pressure of the elastic body 2 is reduced and the diameter is reduced. Further, the mesh body 3 is reduced in diameter and extended in the tube axis direction. For this reason, the elastic contraction body 1 extends in the tube axis direction and returns to the original state. Accordingly, the gripping devices 20 and 21 return to the original standing state so that the gripping state of the rod-like body 50 by the gripping devices 20 and 21 is released. The rod-shaped body 50 can be taken out from the base 22.

  In the above embodiment, the stopper 12 is formed in a substantially cylindrical shape so that the end of the elastic contraction body 1 can be inserted. For example, the stopper 12 is formed in a substantially cylindrical shape and elastically contracted. It is also possible to configure so that the end of the body 1 is not inserted. That is, the stopper 12 is configured by a nut-like member having a screw portion 13 that can be screwed to the screw portion 8 of the terminal member 4 on the inner peripheral surface. Also in this case, the end surface of the protection member 9 is abutted and held by the front end surface 12a of the stopper 12 by screwing the terminal member 4 and the stopper 12 to the outside of the protection member 9 (on the other end side of the terminal member 4). Movement is restricted.

  Further, the actuator according to the present embodiment can be widely applied to various devices other than the robot hand A, and the specific application range is not limited to this.

Second Embodiment
Furthermore, the actuator 24 is not limited to the one described in the above embodiment, and may be configured as follows. The main configuration of the actuator 24 is the same as that of the actuator 24 according to the above-described embodiment. Common parts are denoted by the same reference numerals, description thereof is omitted, and only different parts will be described below.

  That is, as shown in FIG. 4, unlike the above embodiment, the stopper 12 is composed of a pair of halves 41, 41 having convex portions 40 on the inner peripheral surface. By tightening the hose band 42, the stopper 12 is fixed by engaging the end portion side of the elastic contraction body 1 in the concave groove 6 of the terminal member 4 with the convex portion 40. In this way, by engaging the elastic contraction body 1 in the recessed groove 6 in a pressed state, the fixed state of the elastic contraction body 1 and the terminal member 4 becomes strong. Also in this case, the movement of the protective member 9 outward (the other end side of the terminal member 4) is restricted by the abutment between the front end surface 12a of the stopper 12 and the other end surface 9c of the protective member 9, and the first The same effects as those of the first embodiment can be obtained. Note that the terminal member 4 in this embodiment does not have the screw portion 8 as in the first embodiment.

  Further, in each of the above embodiments, the end surface 12a of the stopper 12 is held in contact with the end surface 9c of the protection member 9 to serve as movement restriction means for the protection member 9. However, the movement restricting means is not limited to such a stopper 12 in any way.

  Further, the protective member 9 in each of the above embodiments is fixed to the one end side of the terminal member 4 via the elastic contraction body 1 by the hose band 10, but the fixing means for the protective member 9 is never limited to this. It is not limited.

  Moreover, in each said embodiment, although the skirt part 9b is formed in the one end part of the protection member 9, this skirt part 9b should just be formed as needed, and may be abbreviate | omitted.

  Further, when one end of the terminal member 4 is inserted into the elastic contraction body 1, an adhesive may be applied to the outer peripheral surface of the terminal member 4. In this case, as shown in FIG. 5, when the annular groove 15a is formed in the circumferential direction in the step portion 15 of the terminal member 4, the applied adhesive is held in the annular groove 15a. Thereby, not only the integrity of the elastic contraction body 1 and the terminal member 4 is improved, but also the adhesive applied to the terminal member 4 is elastically contracted when the terminal member 4 is inserted into the elastic contraction body 1. 1 is not peeled off, and it does not flow into the through hole 5 of the terminal member 4 and obstruct the flow of the working fluid.

  In addition, the specific configuration such as the shape of each part of the terminal member 4 can be arbitrarily changed within the range intended by the present invention.

  As described above, the present invention is useful for an actuator that uses the expansion and contraction force generated when the elastic contraction body is pressurized.

The actuator which concerns on 1st Embodiment is shown, (a) is a front view, (b) is sectional drawing. It is a perspective view of the robot hand provided with the actuator. (A) And (b) is a perspective view which shows the mode of operation | movement of a robot hand. The actuator which concerns on 2nd Embodiment is shown, (a) is a front view, (b) is sectional drawing. It is a front view of a terminal member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic contraction body 2 Elastic body 3 Net-like body 4 Terminal member 6 Groove 8 Screw part 9 Protection member 9c End surface 12 Stopper 13 Screw part 40 Convex part

Claims (7)

An elastic contraction body having a cylindrical elastic body to which a working fluid is supplied and discharged, and a net-like body externally fitted to the elastic body;
One end portion is inserted into both ends of the elastic contraction body , and a terminal member provided with a plurality of step portions formed on the one end portion side outer peripheral surface so as to increase in diameter toward the other end portion side ;
A protective member fixed to the step portion of the terminal member via the elastic contraction body in order to restrict the outward expansion of the elastic contraction body;
And an restricting means for restricting the protective member from moving to the other end side of the terminal member.   2. The actuator according to claim 1, wherein the restricting means is a stopper provided on the terminal member so as to hold an end surface of the protective member positioned on the other end side of the terminal member. An elastic contraction body having a cylindrical elastic body to which a working fluid is supplied and discharged, and a net-like body externally fitted to the elastic body;
A terminal member having one end inserted into both ends of the elastic contraction body;
A protective member fixed to one end side of the terminal member via the elastic contraction body in order to restrict the outward expansion of the elastic contraction body;
Regulation means for regulating the protection member so as not to move to the other end side of the terminal member,
The restricting means is a stopper provided on the terminal member to hold the end face of the protective member located on the other end side of the terminal member,
The inner peripheral surface of the stopper, luer actuator such are screwable threaded portion to the threaded portion formed on the other end side outer peripheral surface provided with the terminal members.   2. The actuator according to claim 1, wherein the restricting means is a stopper provided on the elastic contraction body so as to hold an end surface of a protective member positioned on the other end side of the terminal member. An elastic contraction body having a cylindrical elastic body to which a working fluid is supplied and discharged, and a net-like body externally fitted to the elastic body;
A terminal member having one end inserted into both ends of the elastic contraction body;
A protective member fixed to one end side of the terminal member via the elastic contraction body in order to restrict the outward expansion of the elastic contraction body;
Regulation means for regulating the protection member so as not to move to the other end side of the terminal member,
The restricting means is a stopper provided on the elastic contraction body to hold the end face of the protective member located on the other end side of the terminal member,
Both the groove is formed on the outer peripheral surface of the terminal member, the convex portion is formed on the inner peripheral surface of the stopper, that Do is engaged into the groove elastic contraction member is pressed by and convex portions actuators.   The actuator according to claim 3, wherein the protective member is detachably provided on the elastic contraction body.   The actuator according to any one of claims 2, 4, and 5, wherein the protective member and the stopper are detachably provided on the elastic contraction body.

Images