JP4211325B2 - Linear actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dust-proof type linear motion actuator used in, for example, a clean room.
[0002]
[Prior art]
As a mechanism unit for reciprocating a workpiece in a single axis direction in a clean room, for example, a dust-proof type linear motion actuator as described in JP-A-8-290384 is known. This type of linear motion actuator includes a carriage that transports a workpiece and a carriage drive mechanism that reciprocally drives the carriage in one axial direction. The carriage drive mechanism is housed in a dust-proof case and is generated into a clean room. The amount of dust is suppressed.
[0003]
[Problems to be solved by the invention]
In such a linear actuator, the carriage drive mechanism housed in the dustproof case is composed of, for example, a linear guide and a ball screw, so that the workpiece mounted on the carriage can be reciprocated with high accuracy in one axis direction. Can do. However, the length of the dust-proof case that houses the carriage drive mechanism needs to be longer than at least the work transport distance, which increases the installation area on the floor.
[0004]
The present invention has been made paying attention to such problems, and can be used in a clean room, and the length of the dust-proof case for accommodating the carriage drive mechanism is made smaller than the work conveyance distance. It is an object of the present invention to provide a compact linear actuator that can be used.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a linear motion actuator according to the present invention includes a carriage that transports a workpiece, a carriage drive mechanism that reciprocates the carriage in one axis direction, and a fixed dustproof case that houses the carriage drive mechanism. a linear actuator and a movable dustproof case by multiplying the stroke of the carriage have a stroke multiplier mechanism for transmitting to said workpiece, said stroke multiplier mechanisms, fixed to the carriage, this A workpiece mounting seat for holding the workpiece through an opening window formed in the movable dustproof case, a linear guide having a slider for moving the workpiece mounting seat in the movement direction of the carriage, and moving the carriage of the linear guide slider Traction belt that pulls in the direction, and the amount of movement of the carriage by using this traction belt Depending was composed of a travel drive mechanism for moving and driving it, characterized in that the traction belt provided so as to close the opening window in said movable dustproof case.
[0006]
With such a configuration, the workpiece can be transported with the carriage moving stroke approximately halved. Therefore, the length of the fixed dustproof case that accommodates the carriage drive mechanism can be made shorter than the transport distance of the workpiece, and thus the fixed dustproof case can be made compact.
Then, the stroke multiplication mechanism, a movable dustproof case fixed before Symbol carriage, and the workpiece mounting seat for holding the workpiece through the opening formed window to the movable dustproof case, moving the workpiece mounting seat of the carriage A linear guide having a slider that moves in the direction, a traction belt that pulls the slider of the linear guide in the movement direction of the carriage, and a travel drive mechanism that drives the traction belt according to the amount of movement of the carriage Since the traction belt is provided so as to close the opening window in the movable dustproof case, dust such as abrasion powder generated in the movable dustproof case is outside the movable dustproof case (for example, in a clean room) from the opening window. Therefore, it can be suitably used even in a clean room.
[0007]
As the traction belt, as in the second aspect of the present invention, it is possible to use those which are formed in a flat belt shape, by using such a traction belt, relatively the dusting Compared with the case where a high timing belt is used as a traction belt, the amount of dust generated to the outside can be kept low.
Further, as the movable dustproof case, as in the invention according to claim 3 , a movable dustproof case having an exhaust hole communicating with the fixed dustproof case through an exhaust passage formed in the carriage can be used. By using such a movable dustproof case, the air in the movable dustproof case is exhausted into the fixed dustproof case, so that the amount of dust released from the opening window of the movable dustproof case can be reduced. it can.
According to a fourth aspect of the present invention, the fixed dustproof case includes a forced exhaust means for forcibly exhausting the inside of the fixed dustproof case and forcibly exhausting the interior of the movable dustproof case through the exhaust passage and the exhaust hole. Is preferably attached.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A side view, a plan view, and a front view of a linear motion actuator according to an embodiment of the present invention are shown in FIGS. As shown in these drawings, a linear motion actuator 10 according to an embodiment of the present invention includes a box-shaped fixed dustproof case 11, and the fixed dustproof case 11 is shown in FIG. Thus, a carriage drive mechanism 13 that reciprocates the carriage 12 in one axis direction is accommodated.
[0009]
The carriage drive mechanism 13 includes a linear guide 14 and a ball screw 15, and the guide rail 14 a of the linear guide 14 is fixed to the bottom surface of the fixed dust-proof case 11 by a plurality of bolts (not shown). Further, the guide rail 14a has a substantially U-shaped cross section along the width direction, and a belt-like seal body 24, which will be described later, is provided between the lower surface center portion of the guide rail 14a and the bottom surface center portion of the fixed dustproof case 11. Is formed in the longitudinal direction (left and right direction in FIG. 1) of the fixed dustproof case 11.
[0010]
On the other hand, the slider 14 b of the linear guide 14 is integrated with the nut 15 a of the ball screw 15, and the rotational torque of the drive motor 17 provided outside the fixed dust-proof case 11 causes the timing pulley 18, the timing belt 19, and the ball screw 15. When it is transmitted to the screw shaft 15b of the ball screw 15 via a timing pulley (not shown) attached to the screw shaft 15b, the nut 15a moves integrally with the nut 15a in the longitudinal direction. The timing belt 19 is stretched between the two timing pulleys described above through an opening provided on the side surface of the fixed dustproof case 11. The output shaft of the drive motor 17 and the timing pulley 18 are accommodated in the motor case 20, and the opening on the side surface of the fixed dustproof case described above is closed by the motor case 20. The joint between the motor case 20 and the fixed dust-proof case 11 has an airtight structure with a packing 21.
[0011]
The carriage 12 is attached to the upper surface of the slider 14 b via a connecting plate 22, and the carriage 12 is an elongated rectangular shape formed at the center of the upper surface of the fixed dustproof case 11 when the slider 14 b moves in the longitudinal direction of the fixed dustproof case 11. The inside of the opening window 23 (see FIGS. 2 and 4) having a shape is moved in the longitudinal direction of the fixed dust-proof case 11.
[0012]
The opening window 23 is closed by a steel belt-like seal body 24, and a seal body guide groove for guiding the belt-like seal body 24 in the longitudinal direction of the fixed dustproof case 11 at the left and right side edges in FIG. 25 (see FIG. 6) are formed to face each other. In addition to steel, the belt-shaped sealing body 24 can be preferably used if it is made of a material with low dust generation properties such as polyurethane-impregnated canvas or plastic.
[0013]
The belt-like seal body 24 is formed in a flat belt shape, and both ends in the longitudinal direction of the belt-like seal body 24 are fixed to both ends on the moving side of the carriage 12. Further, as shown in FIG. 4, the belt-like seal body 24 is supported by a plurality of pulleys 26 provided in the fixed dustproof case 11 so as to be able to travel in the longitudinal direction of the fixed dustproof case 11.
[0014]
As shown in FIGS. 1 to 3, the carriage 12 is equipped with a stroke multiplication mechanism 27 that multiplies the stroke of the carriage 12 and transmits it to the workpiece W. The stroke multiplication mechanism 27 includes a box-shaped movable dustproof case 28 attached to the movable dustproof case mounting surface 12a (see FIG. 4) of the carriage 12 with its longitudinal direction coinciding with the longitudinal direction of the fixed dustproof case 11. A stroke transmission mechanism 40 (see FIG. 8) is provided in the movable dust-proof case 28 and transmits the movement stroke of the carriage 12 to the workpiece W. An exhaust hole 33 (see FIG. 7) is formed in the center of the bottom surface of the movable dust-proof case 28. Is formed. The exhaust hole 33 communicates with the fixed dust-proof case 11 through an exhaust passage 34 (see FIGS. 4 and 5) formed in the carriage 12. The fixed dust-proof case 11 includes the interior of the fixed dust-proof case 11. An exhaust fan 35 (see FIG. 1) is attached as a forced exhaust means for forcibly exhausting and forcibly exhausting the movable dustproof case 28 through the exhaust passage 34 and the forced exhaust hole 33.
[0015]
More specifically, the exhaust passage 34 is formed along the longitudinal direction of the fixed dustproof case 11 in the central portion of the upper surface of the connecting plate 22 and a through hole 34a having a substantially T-shaped axial cross section that penetrates the carriage 12 up and down. And a through-hole 34c provided in a portion corresponding to the fan 35 through the bottom surface of the guide rail 14a and the fixed dust-proof case 11.
[0016]
The movable dustproof case 28 has a length of about 2/3 of the fixed dustproof case 11, and elongated rectangular windows 29a and 29b (see FIG. 8) are formed on the left and right sides of the movable dustproof case 28. Is formed from one longitudinal end of the movable dustproof case 28 to the other longitudinal end.
As shown in FIG. 7, the stroke transmission mechanism 40 includes a workpiece mounting seat 30 that holds a workpiece W through one opening window (for example, 29 a) of the movable dustproof case 28, and the carriage 12 moves through the workpiece mounting seat 30. A linear guide 41 having a slider 31 that moves in the direction of movement and a guide rail 32 that guides the slider 31 in the direction of movement of the carriage 12, a traction belt 36 that pulls the slider 31 of the linear guide 41 in the direction of movement of the carriage 12, and The traction belt 36 includes a travel drive mechanism unit 42 that travels and drives the traction belt 36 according to the amount of movement of the carriage 12.
[0017]
The steel traction belt 36 is formed in a flat belt shape, and both ends in the longitudinal direction of the traction belt 36 are fixed to both ends on the moving side of the work mounting seat 30. The traction belt 36 is provided in the movable dustproof case 28 so as to close the opening windows 29a and 29b of the movable dustproof case 28. The traction belt 36 is provided on the upper edge portion and the lower edge portion of the opening windows 29a and 29b. Traction belt guide grooves 37 (see FIGS. 8 and 9) for guiding 36 in the longitudinal direction of the movable dustproof case 28 are formed to face each other.
[0018]
The traveling drive mechanism 42 includes four pulleys 38 that support the traction belt 36 so that the traction belt 36 can travel. These pulleys 38 are arranged at four corners in the movable dustproof case 28. Further, the traveling drive mechanism 42 includes a traction belt fixing member 39 (see FIG. 9) including a mounting plate 39a and a fixing bracket 39b, and the traction belt 36 has a central portion in the longitudinal direction fixed by the traction belt fixing member 39. 11 is fixed. The traction band 36 may be made of a material other than steel as long as it has a low dusting property.
[0019]
In such a configuration, when the rotational torque of the drive motor 17 is transmitted to the screw shaft 15b of the ball screw 15 via the timing pulley 18, the timing belt 19, and a timing pulley (not shown), the nut 15a and the slider 14b are fixed to the fixed dustproof case 11. The carriage 12 and the movable dust-proof case 28 move in the longitudinal direction of the fixed dust-proof case 11 together with this. Then, when the movable dustproof case 28 moves in the longitudinal direction of the fixed dustproof case 11, the traction belt 36 of the stroke transmission mechanism 40 provided in the movable dustproof case 28 in accordance with this moves according to the amount of movement of the movable dustproof case 28. As a result, the workpiece mounting seat 30 and the slider 31 of the stroke transmission mechanism 40 are pulled and driven in the longitudinal direction of the fixed dust-proof case 11. At this time, the workpiece mounting seat 30 and the slider 31 move in the longitudinal direction of the fixed dust-proof case 11 with a stroke obtained by adding the movement amount of the carriage 12 and the movement amount of the movable dust-proof case 28. The workpiece W can be transported in half. Therefore, in the above-described embodiment, the length of the fixed dustproof case 11 that accommodates the carriage drive mechanism 13 can be made shorter than the transport distance of the workpiece W, and thereby the fixed dustproof case 11 can be made compact. it can.
[0020]
Further, as in the above-described embodiment, the stroke transmission mechanism 40 includes a workpiece mounting seat 30 that holds the workpiece W through one opening window 29a of the movable dust-proof case 28, and the workpiece mounting seat 30 in the moving direction of the carriage 12. A linear guide 41 having a slider 31 to be moved, a traction belt 36 that pulls the slider 31 of the linear guide 41 in the movement direction of the carriage 12, and a travel drive that drives the traction belt 36 according to the amount of movement of the carriage 12. When the traction belt 36 is provided in the movable dustproof case 28 so as to close the opening windows 29a and 29b, the opening window 29a is provided in a portion where the work mounting seat 30 and the traction belt fixing member 39 are not located. , 29b are always blocked by the traction belt 36, so that they are generated in the movable dustproof case 28. Dust abrasion powder can be prevented from being released opening window 29a of the movable dustproof case 28, from 29b on the outer movable dustproof case 28, can thereby be suitably used in a clean room.
[0021]
Furthermore, in the above-described embodiment of the present invention, the traction band 36 is formed in a flat belt shape having a low dust generation property. The amount of dust generated can be reduced.
In the embodiment of the present invention described above, when the exhaust fan 35 is operated, air in the movable dustproof case 28 is exhausted into the fixed dustproof case 11 through the exhaust hole 33 and the exhaust passage 34. It is possible to prevent dust such as wear powder generated in the above from being released out of the movable dustproof case 28 from the opening window 29. Further, when the exhaust fan 35 is operated, the inside of the fixed dustproof case 11 and the inside of the movable dustproof case 28 become negative pressure. Accordingly, even if the belt-like seal body 24 and the traction belt 36 are in contact with or not in contact with the groove surfaces of the guide grooves 26 and 37, the gap between the two becomes small and the inside is made negative pressure. It is possible to prevent dust such as abrasion powder generated in the fixed dustproof case 11 and the movable dustproof case 28 from being released to the outside through the opening windows 23, 29a, and 29b and becoming a contamination source in the clean room.
[0022]
Note that, by setting the cross-sectional shape of the traction belt guide groove 37 to a cross-sectional shape as shown in FIG. 10, that is, a cross-sectional shape having a narrow opening side, dust generation to the outside can be more reliably prevented. Further, although an exhaust fan is used as means for exhausting the inside of the fixed dustproof case 11 and the movable dustproof case 28, the present invention is not limited to this, for example, as disclosed in JP-A-8-290384. It is also possible to use an appropriate number of exhaust means in which air vent pipes are passed through the fixed dustproof case 11 from the outside so that one end faces the inside and the other end is connected to an exhaust pump.
[0023]
Further, in the above-described embodiment, the single stage configuration of the stroke multiplication mechanism 27 is provided on the carriage 12. However, for example, by providing the multistage configuration of the stroke multiplication mechanism on the carriage 12, the workpiece can be moved at a higher speed. Can do. Moreover, although the opening windows 29a and 29b are formed on the left and right side surfaces of the movable dustproof case 28, the present invention is not limited to this. For example, the opening windows 29a and 29b are formed on the upper and lower surfaces of the movable dustproof case 28. Also good. In that case, the mounting plate 39a of the traction belt fixing member 39 is fixed so as to face the opening window on the lower surface, and the work mounting seat 30 is configured to extend from the opening window on the upper surface. Are also changed as appropriate.
[0024]
Further, both end portions of the traction band 36 are fixed to both end portions on the moving side of the slider 31, and the center portion in the longitudinal direction of the traction band 36 is fixed to the traction belt fixing member 39. May be fixed to the traction belt fixing member 39 and the central portion in the longitudinal direction of the traction band 36 may be fixed to the slider 31. Alternatively, two traction bands 36 may be used, and one end of each may be fixed to the slider 31 and the other end may be fixed to the traction belt fixing member 39. Further, by using four pulleys 26 and 38 respectively, the ratio of the stroke length of the carriage 12 and the slider 31 to the length of the fixed dustproof case 11 and the movable dustproof case 28 can be increased. If the advantage may be sacrificed somewhat, for example, two pulleys 26 or 38 may be provided. Furthermore, the carriage drive mechanism 13 is not limited to a combination of a ball screw and a linear guide, but may be another method such as a combination of a linear motor or a belt and a pulley.
[0025]
【The invention's effect】
As described above, according to the linear motion actuator according to the first aspect of the present invention, the workpiece can be transported with the carriage moving stroke approximately halved. Therefore, the fixed dustproof case that accommodates the carriage drive mechanism can be used. The length can be made shorter than the workpiece transport distance, and the fixed dustproof case can be made compact.
[0026]
Further, according to the linear actuator according to the invention of claim 1, in addition to the above effects, to prevent dust abrasion powder generated in the movable dustproof case is released from the open window outside the movable dustproof case be able to.
According to the linear motion actuator of the second aspect of the invention, in addition to the effect of the first aspect of the invention, the opening window formed in the movable dustproof case can be reliably sealed by the belt-like sealing body.
According to the linear motion actuator of the third aspect of the invention, in addition to the effect of the first aspect of the invention, it is possible to reduce the amount of dust released to the outside from the opening window of the movable dustproof case.
[Brief description of the drawings]
FIG. 1 is a side view of a linear actuator according to an embodiment of the present invention.
FIG. 2 is a plan view of the linear motion actuator shown in FIG.
FIG. 3 is a front view of the linear motion actuator shown in FIG. 1;
4 is a view showing a part of the linear motion actuator shown in FIG. 1; FIG.
5 is a cross-sectional view in the direction perpendicular to the axial direction of FIG. 4;
6 is a cross-sectional view taken along the line VI-VI in FIG.
7 is a cross-sectional view taken along the line VII-VII in FIG.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
9 is a cross-sectional view taken along the line IX-IX in FIG.
FIG. 10 is a cross-sectional view of a seal body guide groove for explaining another embodiment of the present invention.
[Explanation of symbols]
11 Fixed dustproof case W Workpiece 12 Carriage 13 Carriage drive mechanism 14 Linear guide 14a Guide rail 14b Slider 15 Ball screw 15a Nut 15b Screw shaft 16 Seal body travel path 17 Drive motor 18 Timing pulley 19 Timing belt 20 Motor case 21 Packing 22 Connecting plate 23 Opening window 24 Band-shaped sealing body 25 Sealing body guide groove 26 Pulley 27 Stroke multiplication mechanism 28 Movable dustproof case 29a, 29b Opening window 30 Workpiece mounting seat 31 Slider 32 Guide rail 33 Forced exhaust hole 34 Exhaust passage 35 Exhaust fan 36 Towing band 37 Pull band guide groove 38 Pulley 39 Pull band fixing member 40 Stroke transmission mechanism 41 Linear guide 42 Travel drive mechanism

Claims (4)

A linear motion actuator comprising a carriage for transporting a workpiece, a carriage drive mechanism for reciprocally driving the carriage in a uniaxial direction, and a fixed dustproof case for accommodating the carriage drive mechanism,
And multiply the stroke of the carriage have a stroke multiplier mechanisms to convey the workpiece,
The stroke multiplication mechanism includes a movable dustproof case fixed to the carriage, a workpiece mounting seat for holding the workpiece through an opening window formed in the movable dustproof case, and the workpiece mounting seat in the moving direction of the carriage. A linear guide having a slider to be moved, a traction belt that pulls the slider of the linear guide in the movement direction of the carriage, and a travel drive mechanism that drives the traction belt according to the amount of movement of the carriage. A linear motion actuator , wherein the traction belt is provided in the movable dustproof case so as to close the opening window . The linear actuator according to claim 1 , wherein the traction belt is formed in a flat belt shape . The movable dustproof case, according to claim 1 or 2 linear actuator according to characterized in that it has an exhaust hole communicating with the inside the fixed dustproof case through an exhaust passage formed in said carriage. The fixed dustproof case is provided with forced exhaust means for forcibly exhausting the inside of the fixed dustproof case and forcibly exhausting the inside of the movable dustproof case through the exhaust passage and the exhaust hole. Item 4. The linear actuator according to item 3 .

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