JP2005106284A - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the weight saving and cost reduction of an actuator. <P>SOLUTION: A rotary drive source 16 is connected with one end part side of a frame 14, the rotary drive force of the rotary drive source 16 is transmitted to a slider 20 through a driving pulley 48, a belt member 56 and a driven pulley 54, and the slider 20 is displaced along the axial direction of the frame 14 under the action of a guide mechanism 22. The frame 14 and the slider 20 are made out of an aluminum alloy and the like, and first guide rails 42a, 42b mounted on the frame 14 and second guide rails 86a, 86b mounted on a side face of the slider 20 are made out of a quenched metallic material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an actuator capable of linearly reciprocating a slider along a frame under the driving action of a driving source.

  Conventionally, for example, a transport mechanism such as an actuator is used to transport a workpiece.

  As shown in FIG. 12, this actuator is provided with an inner block 2 that is displaceable along the axial direction inside the outer rail 1, and a ball screw 3 extends along the axial direction at a substantially central portion of the inner block 2. Are screwed together.

  A pair of inner wall surfaces 1a and 1b in the outer rail 1 are formed so as to face the inner block 2, and a pair of ball rolling grooves 4a and 4b are formed along the axial direction on the inner wall surfaces 1a and 1b. ing. Ball grooves (not shown) are formed on both side surfaces of the inner block 2 facing the ball rolling grooves 4a and 4b. A return passage 7 in which a plurality of balls 6 circulate is formed inside the inner block 2, and the ball 6 passes between the return passage 7, the ball rolling grooves 4 a and 4 b and a ball groove (not shown). By circulating, the inner block 2 is guided along the outer rail 1 so as to be displaceable.

  Then, the ball screw 3 integrally connected to a drive source such as an electric motor (not shown) rotates, and the inner block 2 screwed to the ball screw 3 under the rotating action extends along the axial direction of the outer rail 1. It is displaced linearly (for example, see Patent Document 1).

JP 2003-075451

  By the way, in the prior art which concerns on patent document 1, when the inner block 2 displaces along the outer rail 1 under the drive effect | action of a drive source, the return channel | path 7 inside the said inner block 2, the ball rolling groove 4a, A plurality of balls 6 circulate between 4b and a ball groove (not shown). However, when the ball 6 circulates between the ball rolling grooves 4a and 4b and the ball groove, a sliding resistance is generated, and the inner wall surfaces 1a and 1b and the inner block 2 of the outer rail 1 are worn.

  Therefore, the outer rail 1 in which the ball rolling grooves 4a and 4b are formed and the inner block 2 in which the ball groove is formed are formed from a metal material (for example, stainless steel) that can be heat-treated (for example, quenching). The outer rail 1 and the inner block 2 are each quenched. As a result, the hardness of the ball rolling grooves 4a, 4b and the ball groove is increased to suppress wear caused by the sliding action of the ball 6. However, when the outer rail 1 and the inner block 2 are subjected to a quenching process, there is a problem that the cost increases with the heat treatment and the manufacturing process increases.

  On the other hand, in recent years, there is a demand for further weight reduction of the actuator.

  The present invention has been made in consideration of the various problems described above, and provides an actuator capable of reducing cost and weight while suppressing wear of a sliding portion in a guide mechanism. Objective.

To achieve the above object, the present invention comprises a frame,
A drive source provided at one end of the frame;
A driving pulley connected to the driving shaft of the driving source and rotatably supported, a driven pulley rotatably supported on the other end side of the frame, the driving pulley and the driven A driving force transmission mechanism including a belt member suspended between the pulleys for use;
A slider in which a driving force is transmitted through the driving force transmission mechanism under a driving action of the driving source, and reciprocatingly moves along an axial direction of the frame;
A set of first guide rails mounted along the axial direction on the inner wall surface of the frame; and a set of second guide rails mounted along the axial direction on the side surface of the slider facing the frame; A guide mechanism that includes a plurality of balls that roll along ball rolling grooves respectively formed in the first and second guide rails, and that guides the slider when the slider is displaced along the frame;
With
The first and second guide rails are formed of a metal material that is separate from the frame and the slider and is subjected to quenching treatment, and the frame and the slider are light metal materials that are lighter than the metal material. Alternatively, it is formed from a high-strength resin material.

  According to the present invention, the ball has a ball rolling groove for rolling a plurality of balls, the first guide rail mounted on the inner wall surface of the frame, and the ball rolling groove for similarly rolling a plurality of balls. The second guide rail formed on the side surface of the slider facing the frame is formed separately from the frame and the slider, and is formed from a metal material that has been subjected to quenching.

  Accordingly, the strengths of the first and second guide rails on which the plurality of balls roll are maintained, wear when the balls slide can be suppressed, and the first and second guides on which the balls roll. The frame and the slider, which are constituent members other than the rails, are not quenched and are made of a light metal material or a high-strength resin material that is lighter than the metal material.

  The first and second guide rails are separated from the frame and the slider, and most of the volume of the actuator is made of a light metal material or a high-strength resin material that is lighter in weight than a material that can be hardened, such as stainless steel. By forming the frame and the slider that occupy the entire area, the overall weight of the actuator can be significantly reduced.

  Also, compared to the case where the entire frame and slider are heat treated to improve the strength, only the first and second guide rails on which a plurality of balls roll are subjected to quenching treatment to improve the strength. Therefore, the cost required for the heat treatment can be reduced.

  Furthermore, the frame and the slider may be formed of an aluminum alloy or a carbon fiber reinforced resin material. Thereby, the weight of the frame and the slider can be reduced, and accordingly, the weight of the entire actuator can be reduced.

  Furthermore, the driving pulley and the driven pulley may be provided directly on the frame. This eliminates the need to connect the members for holding the driving pulley and the driven pulley to the frame, thereby reducing the number of parts and cost of the actuator.

Still further, the present invention provides a frame;
A drive source provided at an end of the frame;
A driving pulley connected to the driving shaft of the driving source and rotatably supported, a driven pulley rotatably supported on the other end of the frame, the driving pulley, and the driven pulley A driving force transmission mechanism including a belt member suspended between the pulleys;
A slider in which a driving force is transmitted through the driving force transmission mechanism under a driving action of the driving source, and reciprocatingly moves along an axial direction of the frame;
A pair of guide rails mounted along the axial direction on the inner wall surface of the frame, and a plurality of rollers that roll along ball rolling grooves formed on the side surfaces of the slider facing the guide rails and the guide rails. A guide mechanism that guides the slider when the slider is displaced along the frame;
With
The guide rail is formed from a metal material that is separate from the frame and subjected to a quenching process, and the frame is formed from a light metal material or a high-strength resin material that is lighter than the metal material. It is characterized by that.

  According to the present invention, a metal having a ball rolling groove on which a plurality of balls roll, a guide rail mounted on the inner wall surface of the frame being formed separately from the frame, and subjected to quenching treatment It is made from a material.

  Therefore, the strength of the guide rail on which a plurality of balls roll is maintained, wear when the balls slide can be suppressed, and the frame, which is a component other than the guide rail on which the balls roll, is quenched. It is not processed and is made of a light metal material or a high-strength resin material that is lighter than the metal material.

  Then, the guide rail is separated from the frame, and a frame that occupies most of the volume of the actuator is formed by a light metal material or a high-strength resin material that is light in weight as compared with a material that can be quenched, such as stainless steel. As a result, the entire actuator can be significantly reduced in weight.

The present invention also includes a frame,
A first unit connected to one end of the frame and provided with a rotational drive source that is driven by an electrical signal, and provided with a driving pulley connected to the rotational drive source;
A second unit connected to the other end of the frame and provided with a driven pulley on which a belt member is suspended between the driving pulley of the first unit;
A slider coupled to the belt member and displaced along the frame under the driving action of the rotational drive source;
With
The first unit and the second unit are integrally assembled to the frame.

  According to the present invention, the first unit having a rotational driving source and a driving pulley for transmitting the driving force of the rotational driving source, and the driven pulley for transmitting the driving force from the driving pulley via the belt member. Since the second pulley having the unit is unitized and connected to the end of the frame, the first and second units can be easily attached to and detached from the frame.

  Therefore, for example, when changing the stroke amount of the slider in the actuator, it is necessary to replace the slider with a frame having a length corresponding to the change in the stroke amount. Even in such a case, the first and second units can be easily removed from the frame, and the first and second units can be easily attached to and used for the replaced new frame.

  As a result, the frame can be easily replaced, and the first and second units can be used as they are, so that the parts can be shared and the cost can be reduced.

  Further, by providing a tension adjusting mechanism for adjusting the tension of the belt member in the second unit, it is possible to suitably adjust the tension even when the tension of the belt member changes due to secular change or the like. .

Furthermore, the tension adjusting mechanism includes a pulley holder that rotatably holds the driven pulley,
A holding bracket for holding the pulley holder so as to be displaceable along the axial direction of the frame;
A spring member interposed between the holding bracket and the pulley holder and biasing the pulley holder closer to the holding bracket;
With
By displacing the pulley holder toward the holding bracket by the elastic force of the spring member, the tension of the belt member suspended between the driven pulley and the driving pulley held by the holding bracket is made constant. It is good to hold.

  Accordingly, the pulley holder is held by the holding bracket provided on the frame, and the driven pulley rotatably held by the pulley holder can be provided so as to be displaceable along the axial direction of the frame by the elastic force of the spring member. . For this reason, even when the tension of the belt member suspended on the driven pulley changes with time, the tension adjustment mechanism suitably adjusts the tension.

  Still further, the holding bracket is formed by pressing a thin plate material, and is provided on the body of the second unit to which the holding bracket is fixed so as to protrude toward the driven pulley, and the spring member is It is preferable to provide a spring guide that can be extended and contracted along the axial direction. Accordingly, since the spring member is held via the spring guide, the spring member can be reliably held without falling off the second unit. In addition, it is possible to manufacture the holding bracket at a low cost by forming it from a pressed thin plate material.

  The pulley holder may be formed by pressing a thin plate material, and the pulley may be rotatably held by the pulley holder via a pair of bearings.

  Further, the pulley holder is formed by pressing a thin plate material, and the pulley holder is formed with a widened portion protruding so as to face the first guide rail attached to the frame, and a ball is formed at an end of the widened portion. A bent portion bent in an arc shape may be formed so as to correspond to the shape of the rolling groove, and the bent portion may be engaged with the ball rolling groove. That is, by forming a bent portion at the end of the widened portion, the bent portion formed in the arc shape is reliably and suitably engaged with the ball rolling groove, and the pulley holder is secured by the widened portion. Can be held in the frame, and displacement in a direction substantially perpendicular to the axis of the frame can be restricted. Therefore, the pulley holder can be more firmly fixed to the frame.

  According to the present invention, the following effects can be obtained.

  That is, it has a ball rolling groove on which a plurality of balls roll, has a first guide rail mounted on the inner wall surface of the frame, and has a similar ball rolling groove, formed on the side surface of the slider facing the frame. Since the strength of the first and second guide rails is ensured by forming the second guide rail made of a metal material that has been subjected to quenching treatment, wear when the ball slides is prevented. Can be suppressed.

  Further, by making the first and second guide rails separate from the frame and the slider, the frame and the slider can be formed from a light metal material or a high-strength resin material that is lighter than the metal material. Can be significantly reduced in weight.

  Furthermore, as compared with the case where the entire frame and slider are subjected to heat treatment to improve the strength, only the first and second guide rails need to be quenched, so that the cost can be reduced.

  Preferred embodiments of the actuator according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  1 to 4, reference numeral 10 indicates an actuator according to the first embodiment of the present invention.

  The actuator 10 is formed with a plurality of mounting holes 12 (see FIGS. 2 and 3), and a flat bottom wall 14a and a pair of side walls 14b and 14c facing each other are integrally formed. A frame 14 (see FIG. 2) is provided, and a rotational drive source 16 is provided on one end side of the frame 14. Further, the actuator 10 has a driving force transmission mechanism 18 that converts the rotational driving force of the rotational driving source 16 into a linear motion and transmits it, and the frame by the linear motion transmitted through the driving force transmission mechanism 18. 14 is provided with a slider 20 that is displaced along the axial direction of 14, and a guide mechanism 22 that guides the slider 20 along the axial direction of the frame 14.

  For example, the frame 14 is formed by extrusion molding, pultrusion molding, or the like on a light metal material such as an aluminum alloy or a light high-strength resin material such as a carbon fiber reinforced plastic CFRP (Carbon Fiber Reinforced Plastics) including a light alloy material or carbon fiber. The first housing 24 is integrally connected to one end portion along the axial direction through a bolt member 28. A second housing 26 is integrally connected to the other end of the frame 14 along the axial direction via a bolt member 28.

  Further, on the upper surfaces of the first housing 24 and the second housing 26, there are screwed the first side cover 30 and the second side cover 32 having a substantially L-shaped cross section so as to connect the first housing 24 and the second housing 26. It is detachably provided via the member 34. The first and second side covers 30 and 32 are provided so as to cover a part of the upper surfaces and side surfaces of the first housing 24 and the second housing 26 and to cover the upper portion of the frame 14.

  Further, a pair of top covers 36 are detachably mounted on the upper surfaces of the first housing 24 and the second housing 26 between the first and second side covers 30 and 32 via screw members 34, respectively. Yes. That is, the upper surfaces of the first and second housings 24 and 26 are entirely covered by the top cover 36 and the first and second side covers 30 and 32.

  Stopper members 38 are provided at one end portions of the first housing 24 and the second housing 26 facing the slider 20 to alleviate an impact when the slider 20 is displaced and brought into contact (see FIG. 3).

  As shown in FIG. 6, a pair of first long grooves 40 a and 40 b that are recessed in a rectangular cross section extend in the axial direction at a portion close to the bottom surface of the inner wall of the frame 14, and the first long grooves Long first guide rails 42a and 42b having substantially the same cross-sectional shape as 40a and 40b are mounted. The pair of first long grooves 40a and 40b are formed to face each other.

  As shown in FIG. 4, the rotary drive source 16 is connected to the bottom surface of the first housing 24 via a screw member (not shown). The drive shaft 44 of the rotational drive source 16 is connected to a drive pulley 48 disposed in the recess 46 of the first housing 24 through an opening 50. The drive pulley 48 is rotatably supported inside the recess 46.

  The first housing 24 in which the rotational drive source 16 and the drive pulley 48 are provided functions as a single drive unit (first unit). That is, for example, when the frame 14 is replaced in order to change the stroke amount of the actuator 10, the drive unit can be easily replaced by assembling the drive unit at the end of a separate frame, Since the drive unit can be used as it is, parts can be shared.

  On the other hand, a driven pulley 54 is rotatably supported in a recess 52 formed in the second housing 26, and extends substantially parallel to the frame 14 between the drive pulley 48 and the driven pulley 54. A belt member 56 is suspended in an annular shape. That is, the drive pulley 48, the driven pulley 54, and the belt member 56 function as the driving force transmission mechanism 18 that transmits the rotational driving force of the rotational driving source 16 to the slider 20 connected to the belt member 56.

  The second housing 26 provided with the driven pulley 54 functions as a single driven unit (second unit). That is, for example, when the frame 14 is replaced in order to change the stroke amount of the actuator 10, the frame 14 can be easily replaced by assembling the driven unit at the end of a separate frame. Since the driven unit can be used as it is, parts can be shared.

  A cylindrical pulley shaft 58 is inserted into a substantially central portion of the driven pulley 54 through a plurality of bearings (not shown). The pulley shaft 58 is attached to an adjustment plate 60 mounted in the recess 52 of the second housing 26. It is fixed by screwing. As shown in FIG. 3, the adjustment plate 60 is locked to the recess 52 of the second housing 26 via a screw member 62 in a direction substantially perpendicular to the axis, and a plurality of the screw members 62 engage with each other. The second housing 26 is provided so as to be displaceable along the long hole 64, that is, along the axial direction of the second housing 26.

  An adjustment screw 68 is screwed into the adjustment plate 60 through a hole 66 formed so as to penetrate the second housing 26. The head of the adjustment screw 68 is housed inside the hole so that it does not protrude from the end surface of the second housing 26 (see FIG. 4).

  Then, since the adjusting plate 60 is displaced along the axial direction of the frame 14 by screwing the adjusting screw 68, the driven pulley 54 fixed to the adjusting plate 60 can be displaced integrally. Therefore, the tension of the belt member 56 suspended between the drive pulley 48 and the driven pulley 54 can be adjusted. That is, for example, by adjusting the screwing amount with respect to the adjustment plate 60 by screwing the adjustment screw 68 from the outside via a hexagon wrench or the like, the long hole in which the adjustment plate 60 is engaged through the screw member 62 is used. The tension in the belt member 56 can be suitably adjusted by displacing the inside of the concave portion 52 of the second housing 26 along the line 64 by a minute distance.

  As shown in FIG. 6, the slider 20 is a lightweight high-strength resin such as a light metal material such as an aluminum alloy or a light alloy material, or a carbon fiber reinforced plastic CFRP (Carbon Fiber Reinforced Plastics) containing carbon fibers. It is made of a material and is provided inside the frame 14 so as to be displaceable along the axial direction.

  The slider 20 is formed at a substantially central portion and is formed so as to slightly protrude upward from between the first side cover 30 and the second side cover 32, and both sides of the main body portion 70. And a pair of flange portions 72a and 72b formed at a predetermined interval, and space portions 74a and 74b formed between the main body portion 70 and the flange portions 72a and 72b, respectively. A table or the like on which a workpiece is placed is mounted on the upper surface of the main body 70 via a screw or the like (not shown).

  Further, the flange portions 72a and 72b are formed to be smaller in the height direction than the main body portion 70, and the second long grooves 76a having a rectangular cross section each recessed by a predetermined depth are formed on both side surfaces facing the frame 14, respectively. 76b extends along the axial direction. The second long grooves 76a and 76b are formed at positions facing the first long grooves 40a and 40b formed in the frame 14, respectively.

  The space portions 74a and 74b are formed between the main body portion 70 and the flange portions 72a and 72b so as to be depressed by a predetermined depth downward from the upper surfaces of the flange portions 72a and 72b. As shown in FIGS. 3 and 6, a plate-like belt stopper 80 is attached to one side surface along the axial direction of the main body portion 70 via a bolt 78. 80, both end portions of the belt member 56 are sandwiched (see FIG. 3). Therefore, when the belt member 56 is fixed to the slider 20, the slider 20 and the belt member 56 are displaced integrally.

  At that time, as shown in FIG. 3, a set of recesses 84 that are cut out in a substantially semicircular cross section is formed on one side of the slider 20 at a position facing the bolt hole 82 of the belt stopper 80. Therefore, when the belt stopper 80 is fixed to the slider 20, the head of the bolt 78 is accommodated in the recess 84 and does not protrude from one side of the slider 20.

  On the other hand, a belt member 56 suspended between the drive pulley 48 and the driven pulley 54 is inserted into the space 74a between the other side surface of the main body 70 and the flange portion 72a (see FIG. 6).

  As shown in FIG. 6, the guide mechanism 22 includes a pair of first guide rails 42 a and 42 b mounted along the first long grooves 40 a and 40 b of the frame 14, and a second long groove 76 a on the side surface of the slider 20. , 76b, a set of second guide rails 86a, 86b, and a set of ball rollers which are close to the second guide rails 86a, 86b and penetrate the inside of the slider 20 along the axial direction. It consists of a moving hole 88. The first guide rails 42a and 42b and the second guide rails 86a and 86b are disposed at positions facing each other.

  The first guide rails 42a and 42b and the second guide rails 86a and 86b are formed of a prismatic material made of a metal material that can be hardened (hereinafter referred to as hardened steel). In the first guide rails 42a and 42b, a first ball rolling groove 90 having a substantially arc-shaped cross section in which a ball 89 rolls on a side surface facing the second guide rails 86a and 86b extends along the axial direction. Formed as follows. On the other hand, in the second guide rails 86a and 86b, a second ball rolling groove 92 having a substantially arc-shaped cross section on which the ball 89 rolls on the side surface facing the first guide rails 42a and 42b extends along the axial direction. It is formed to exist.

  Further, as a method of mounting the first guide rails 42a, 42b and the second guide rails 86a, 86b in the first and second long grooves 40a, 40b, 76a, 76b, respectively, adhesion, press-fitting, welding, etc. Either method may be used.

  Further, as shown in FIG. 2, the guide mechanism 22 is mounted on a side surface of the slider 20 and a pair of plates 96 and a cover 98 that are integrally connected to the lower portion of the slider 20 via a screw member 94. Return guide 100. It is preferable that the plate 96, the cover 98, and the return guide 100 are each formed from a resin material. The plate 96, the cover 98, and the return guide 100 are configured by the same components on one side and the other side of the slider 20.

  In the cover 98, a ball return groove 102 is formed on an end surface in contact with the slider 20, and in this case, the first ball rolling groove 90 in the first guide rails 42a and 42b and the second ball in the second guide rails 86a and 86b. The rolling groove 92, the ball rolling hole 88 penetrating the slider 20, and the ball return groove 102 constitute an annular endless circulation track on which a plurality of balls 89 roll.

  Further, the frame 14, the first housing 24, and the second housing 26 of the actuator 10 shown in FIG. 4 are integrally formed, and as shown in FIG. Each of the pulley 54 and the slider 20 may be held. In this case, end plates 104a and 104b are attached to both ends of the frame 15 so as to be substantially orthogonal to the axis of the frame 15, respectively. Further, a set of holding blocks 106 each having a stopper member 38 is provided on the upper surface of the frame 15, and the stopper member 38 is provided so as to face the end surface of the slider 20.

  As a result, the number of parts can be reduced by integrating the frame 15 in the actuator 10 so that the manufacturing time of the actuator 10 can be shortened, and at the same time, the cost can be reduced. Can do.

  The actuator 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation and effect of the actuator will be described.

  By supplying current to the rotational drive source 16 from a power source (not shown), the drive shaft 44 rotates under the rotational action of the rotational drive source 16, and the rotational drive force of the drive pulley 48 connected to the drive shaft 44 is driven. It is transmitted to a belt member 56 suspended between the pulley 54. Then, the slider 20 to which both end portions of the belt member 56 are fixed is displaced along the axial direction of the frame 14 integrally under the guide action of the guide mechanism 22. Under the control action of a controller (not shown), the polarity of the current supplied to the rotary drive source 16 is reversed to reverse the displacement direction of the slider 20 so that the slider 20 moves along the axial direction of the frame 14. Can be reciprocated.

  When the slider 20 reciprocates along the axial direction of the frame 14, a plurality of balls 89 roll along the first ball rolling groove 90 and the second ball rolling groove 92, thereby moving along the frame 14. The slider 20 can be displaced smoothly.

  As described above, in the first embodiment, the first guide rails 42a and 42b in which the first ball rolling grooves 90 on which the plurality of balls 89 roll and the second ball rolling grooves 92 are formed. The second guide rails 86a and 86b are configured separately from the frame 14 and the slider 20. And the 1st and 2nd guide rails 42a, 42b, 86a, 86b in which the 1st ball rolling groove 90 and the 2nd ball rolling groove 92 are formed are formed from hardened steel which can be hardened. As a result, the frame 14 and the slider 20 occupying most of the volume of the actuator 10 can be formed from aluminum alloy or the like, carbon fiber reinforced plastic, or the like, and the overall weight of the actuator 10 can be greatly reduced.

  In addition, since the first guide rails 42a and 42b and the second guide rails 86a and 86b are made of a metal material that has been subjected to heat treatment such as quenching, the first guide rails 42a and 42b and the second guide rails 86a and 86b are moved by sliding when the ball 89 rolls. Wear of the first guide rails 42a and 42b and the second guide rails 86a and 86b can be suppressed.

  As a result, the first guide rails 42a and 42b and the second guide rails 86a and 86b on which the balls 89 roll are only compared with the conventional technique in which the entire frame 14 and the slider 20 are heat treated to improve the strength. Since it is sufficient to improve the strength by quenching, the cost required for the heat treatment can be reduced.

  On the other hand, a metal material such as a general structural carbon material (SS material) in which the frame 14 and the slider 20 are used as raw materials without being subjected to heat treatment (for example, quenching treatment) instead of aluminum alloy or carbon fiber reinforced plastic. Since the heat treatment such as quenching is unnecessary as compared with the case of using conventional hardened steel such as stainless steel, the cost can be reduced.

  In addition, the hardened steel such as stainless steel and the non-hardened steel that does not require heat treatment such as a general structural carbon material have substantially the same rigidity, so the displacement along the axial direction of the slider 20 In the long stroke type actuator in which the length of the axial direction of the frame 14 is long, by adopting non-hardened steel instead of hardened steel for the frame 14, it is substantially the same as the hardened steel. Costs can be reduced because heat treatment is not necessary while securing rigidity.

  Furthermore, the hardened steel (for example, stainless steel) that has been subjected to the quenching treatment and the non-hardened steel (for example, the general structural carbon material) that is a raw material that has not been subjected to the heat treatment are subjected to temperature changes. Since the linear expansion coefficients indicating the deformation rate are substantially equal, the first and second guide rails 42a, 42b, 86a, 86b formed of hardened steel, the frame 14 and the slider 20 formed of non-hardened steel. However, the respective deformation rates when deforming due to temperature changes are substantially the same.

  As a result, a change in the clearance between the first guide rails 42a and 42b and the second guide rails 86a and 86b in the guide mechanism 22 is suppressed, and the clearance is maintained substantially constant. Can be smoothly displaced along the axial direction.

  Next, a modification of the actuator according to the first embodiment is shown in FIG. The same reference numerals are given to the same components as those of the actuator 10 according to the first embodiment described above, and the detailed description thereof is omitted.

  In the actuator 150 according to this modified example, the ball 89 rolls on the both sides of the slider 152 facing the first guide rails 42a and 42b mounted in the first long grooves 40a and 40b of the frame 14 and has a substantially arc-shaped cross section. Second ball rolling grooves 154a and 154b are formed. In other words, the second ball rolling grooves 154a and 154b along the axial direction are formed on both side surfaces of the slider 152 by processing.

  The second ball rolling grooves 154a and 154b are formed as a pair at a position facing the first ball rolling groove 90 of the first guide rails 42a and 42b. The ball 89 rolls between the two-ball rolling grooves 154a and 154b. At that time, the slider 152 is formed from a hardened steel (for example, stainless steel) that has been subjected to a quenching process, and the frame 14 is made of a light metal material such as an aluminum alloy or a light alloy material, It is good to form from non-hardened steel, such as lightweight high-strength resin, such as carbon fiber reinforced plastic, and general structural carbon material.

  That is, by forming a pair of second ball rolling grooves 154a and 154b directly on both sides of the slider 152, the slider 20 and the second guide rail 86a in the actuator 10 in the first embodiment are provided. Compared with the case where 86b is formed separately, the process of mounting the second guide rails 86a and 86b on the slider 20 can be shortened.

  Further, when the frame 14 is formed from non-hardened steel such as a general structural carbon material, the slider 152 is formed from hardened steel having a linear expansion coefficient substantially equal to that of the non-hardened steel. The respective deformation rates when the slider 152 is deformed by the temperature change are substantially the same.

  As a result, when a temperature change occurs in the operating environment in the actuator 150, the clearance between the second ball rolling grooves 154a and 154b of the slider 152 and the first ball rolling groove 90 does not change and remains substantially constant. Thus, the slider 152 can be smoothly displaced along the axial direction.

  Next, an actuator 200 according to a second embodiment is shown in FIGS. The same reference numerals are given to the same components as those of the actuator 10 according to the first embodiment described above, and the detailed description thereof is omitted.

  In the actuator 200 according to the second embodiment, the driven unit 202 having the driven pulley 54 is automatically connected to the belt member 56 via a coil spring (spring member) 204 so that the tension of the belt member 56 is always constant as a desired tension. This is different from the actuator 10 according to the first embodiment in that an adjustable tension adjustment mechanism 206 is provided.

  As with the actuator 10 according to the first embodiment shown in FIG. 5, the actuator 200 may be provided with a single long frame 15 instead of the first and second housings 24 and 26. Good. This eliminates the need for the first and second housings 24 and 26, thereby reducing the number of parts and cost in the actuator 200.

  A tension adjusting mechanism 206 provided in the actuator 200 includes a holding bracket 208 fixed to the inner wall surface 207 of the second housing 26, a pulley holder 210 that is held by the holding bracket 208 and rotatably supports the driven pulley 54, The coil spring 204 is interposed between the holding bracket 208 and the pulley holder 210.

  The holding bracket 208 is formed, for example, by pressing a thin plate made of a metal material, and is formed along the inner wall surface 207 of the second housing 26 and is formed along the bottom surface of the second housing 26. It is fixed with a bolt 214 through a mounting flange 212. As shown in FIG. 9, the holding bracket 208 is formed with a protruding portion 216 that protrudes toward the driven pulley 54 so as to have a substantially U-shaped cross section. A cylindrical spring guide 218 fixed to the inner wall surface 207 of the second housing 26 is disposed inside the protrusion 216. The end surface of the spring guide 218 is in contact with the inner wall surface of the protruding portion 216.

  As shown in FIG. 10, the pulley holder 210 is formed, for example, by pressing a thin plate material made of a metal material so as to have a substantially U-shaped cross section, and an insertion hole 220 is formed at one end of the bottomed shape. A spring guide 218 of the holding bracket 208 is inserted therethrough. A pair of bearing holes 222a and 222b are formed on the other end of the pulley holder 210 in the direction substantially orthogonal to the axis of the spring guide 218. The bearing holes 222a and 222b are respectively provided with bearings. 224a and 224b are attached. A cylindrical pulley shaft 226 is inserted into the bearings 224a and 224b, and the driven pulley 54 is held by the pulley shaft 226, whereby the driven pulley 54 is supported on the other end side of the pulley holder 210. The At that time, the driven pulley 54 is rotatably held by the pulley holder 210 via a pair of bearings 224a and 224b on which the pulley shaft 226 is pivotally supported.

  In addition, a coil spring 204 is interposed between one end portion of the pulley holder 210 formed in a bottomed shape and the inner wall surface of the protruding portion 216 in a state where the coil spring 204 is compressed by a predetermined amount. A clearance formed between the inner wall surface of the projecting portion 216 and the outer peripheral surface of the spring guide 218 is disposed. The coil spring 204 always urges the pulley holder 210 in a direction in which the pulley holder 210 is brought close to the inner wall surface 207 of the second housing 26 (arrow X1 direction). Instead of the coil spring 204, a plate-like plate spring or the like may be adopted. In other words, any elastic member having an elastic force that urges the pulley holder 210 in the direction in which the pulley holder 210 approaches the inner wall surface 207 of the second housing 26 (arrow X1 direction) may be used.

  On the other hand, as shown in FIGS. 9 and 11, the other end of the pulley holder 210 is formed with a widened portion 228 widened in a direction substantially perpendicular to the axis of the frame 14 on the lower side of the driven pulley 54, and the widened portion. At both ends of 228, bent portions 230 are formed which are bent toward the center of the pulley holder 210 (see FIG. 11). A pair of bent portions 230 bent so as to be bent are engaged with the first ball rolling grooves 90 of the first guide rails 42a and 42b, respectively.

  Specifically, the outer wall surface of the bent portion 230 is formed in a substantially arc shape in cross section so as to correspond to the cross-sectional shape of the first ball rolling groove 90 that is recessed in an arc shape. The first ball rolling groove 90 is preferably engaged.

  That is, since the pulley holder 210 is engaged with the first guide rails 42a and 42b attached to the frame 14 via the widened portion 228, the pulley holder 210 is displaced in a direction substantially perpendicular to the axis of the frame 14. Is regulated. Thereby, the pulley holder 210 is provided so as to be displaceable only along the axial direction of the frame 14 (in the directions of the arrows X1 and X2), that is, along the first guide rails 42a and 42b and the spring guide 218 by the elastic force of the coil spring 204. It becomes a state.

  As described above, in the tension adjusting mechanism 206 of the actuator 200, the pulley holder 210 that rotatably holds the driven pulley 54 is provided so as to be displaceable only along the axial direction (arrows X1 and X2 directions). The driven pulley 54 is always urged in a direction away from the drive pulley 48 (in the direction of the arrow X1) by a coil spring 204 interposed between the fixed holding bracket 208 and the pulley holder 210.

  Then, by setting the spring force (spring constant) of the coil spring 204 in advance so that the tension of the belt member 56 pulled by the coil spring 204 via the driven pulley 54 becomes an optimum value, Even when the tension of the belt member 56 is reduced due to the extension of the belt member 56, the driven pulley 54 is slightly displaced in the direction away from the driving pulley 48 by the elastic force, and the tension is previously set. It is automatically adjusted to the optimal value that was set.

As a result, conventionally, an operator can adjust the tension of the belt member 56 by visually observing the belt member 56 according to the usage state of the belt member 56 or by measuring the tension of the belt member 56. The complicated maintenance work that has been performed can be eliminated. Further, the holding bracket 208, the pulley holder 210, and the like constituting the tension adjusting mechanism 206 can be pressed by, for example, pressing a thin plate material made of a metal material. The tension adjusting mechanism 206 can be manufactured at low cost, and the cost can be reduced.

It is a perspective view of an actuator concerning a 1st embodiment of the present invention. FIG. 2 is an exploded perspective view in which the actuator of FIG. 1 is partially omitted. It is a partial cross section top view which shows the state which removed the top cover in the actuator of FIG. It is a longitudinal cross-sectional view along the axial direction of the actuator of FIG. It is a longitudinal cross-sectional view along the axial direction which shows the case where the 1st and 2nd housing and frame of the actuator of FIG. 1 are integrally formed. It is a longitudinal cross-sectional view along the VI-VI line of FIG. It is a longitudinal section showing a modification of an actuator concerning a 1st embodiment of the present invention. It is a partially cutaway perspective view of an actuator according to a second embodiment of the present invention. FIG. 9 is a partially enlarged plan view showing a state where a top cover is removed from the actuator of FIG. 8. FIG. 9 is a partially enlarged longitudinal sectional view along the axial direction in the vicinity of the driven unit in the actuator of FIG. 8. It is a longitudinal cross-sectional view along the XI-XI line of FIG. It is a partially cutaway perspective view of an actuator according to the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 150, 200 ... Actuator 14, 15 ... Frame 16 ... Rotation drive source 20, 152 ... Slider 22 ... Guide mechanism 24 ... 1st housing 26 ... 2nd housing 40a, 40b ... 1st long groove 42a, 42b ... 1st guide Rail 48 ... Drive pulley 54 ... Drive pulley 56 ... Belt member 70 ... Main body 72a, 72b ... Flange 74a, 74b ... Space 76a, 76b ... Second long groove 78, 214 ... Bolt 80 ... Belt stopper 86a, 86b ... 2 guide rails 88 ... ball rolling holes 89 ... balls 90 ... first ball rolling grooves 92, 154a and 154b ... second ball rolling grooves 100 ... return guides 102 ... ball return grooves 202 ... driven units 204 ... coil springs 206 ... Tension adjustment mechanism 208 ... Holding bracket 210 ... Pulley holder 16 ... protrusion 218 ... spring guide 228 ... wide portions 230 ... bent portion

Claims (10)

Frame,
A drive source provided at one end of the frame;
A driving pulley connected to the driving shaft of the driving source and rotatably supported, a driven pulley rotatably supported on the other end side of the frame, the driving pulley and the driven A driving force transmission mechanism including a belt member suspended between the pulleys for use;
A slider in which a driving force is transmitted through the driving force transmission mechanism under a driving action of the driving source, and reciprocatingly moves along an axial direction of the frame;
A set of first guide rails mounted along the axial direction on the inner wall surface of the frame; and a set of second guide rails mounted along the axial direction on the side surface of the slider facing the frame; A guide mechanism that includes a plurality of balls that roll along ball rolling grooves respectively formed in the first and second guide rails, and that guides the slider when the slider is displaced along the frame;
With
The first and second guide rails are formed of a metal material that is separate from the frame and the slider and is subjected to quenching treatment, and the frame and the slider are light metal materials that are lighter than the metal material. Alternatively, the actuator is formed from a high-strength resin material. The actuator according to claim 1, wherein
The frame and the slider are formed of an aluminum alloy or a carbon fiber reinforced resin material. The actuator according to claim 1, wherein
The actuator, wherein the driving pulley and the driven pulley are directly provided on the frame, respectively. Frame,
A drive source provided at an end of the frame;
A driving pulley connected to the driving shaft of the driving source and rotatably supported, a driven pulley rotatably supported on the other end of the frame, the driving pulley, and the driven pulley A driving force transmission mechanism including a belt member suspended between the pulleys;
A slider in which a driving force is transmitted through the driving force transmission mechanism under a driving action of the driving source, and reciprocatingly moves along an axial direction of the frame;
A pair of guide rails mounted along the axial direction on the inner wall surface of the frame, and a plurality of rollers that roll along ball rolling grooves formed on the side surfaces of the slider facing the guide rails and the guide rails. A guide mechanism that guides the slider when the slider is displaced along the frame;
With
The guide rail is formed from a metal material that is separate from the frame and subjected to a quenching process, and the frame is formed from a light metal material or a high-strength resin material that is lighter than the metal material. An actuator characterized by that. Frame,
A first unit connected to one end of the frame and provided with a rotational drive source that is driven by an electrical signal, and provided with a driving pulley connected to the rotational drive source;
A second unit connected to the other end of the frame and provided with a driven pulley on which a belt member is suspended between the driving pulley of the first unit;
A slider coupled to the belt member and displaced along the frame under the driving action of the rotational drive source;
With
The actuator, wherein the first unit and the second unit are integrally assembled to the frame. The actuator according to claim 5, wherein
The actuator, wherein the second unit is provided with a tension adjusting mechanism for adjusting the tension of the belt member. The actuator according to claim 6, wherein
The tension adjusting mechanism includes a pulley holder that rotatably holds the driven pulley;
A holding bracket for holding the pulley holder so as to be displaceable along the axial direction of the frame;
A spring member interposed between the holding bracket and the pulley holder and biasing the pulley holder closer to the holding bracket;
With
By displacing the pulley holder toward the holding bracket by the elastic force of the spring member, the tension of the belt member suspended between the driven pulley and the driving pulley held by the holding bracket is made constant. An actuator characterized by holding. The actuator according to claim 7, wherein
The holding bracket is formed by pressing a thin plate material, and the body of the second unit to which the holding bracket is fixed is provided so as to protrude toward the driven pulley, and the spring member is connected to the axis. An actuator, characterized in that a spring guide is provided that is stretchable along a direction. The actuator according to claim 7, wherein
The pulley holder is formed by pressing a thin plate material, and the driven pulley is rotatably held by the pulley holder via a pair of bearings. The actuator according to claim 7, wherein
The pulley holder is formed by pressing a thin plate material, and the pulley holder is formed with a widened portion protruding so as to face the first guide rail mounted on the frame, and a ball portion is formed at an end of the widened portion. An actuator, wherein a bent portion bent in an arc shape is formed so as to correspond to the shape of the rolling groove, and the bent portion is engaged with the ball rolling groove.

Images