JP2008101642A - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator capable of securing working accuracy and suppressing dust and vibration, and appropriate to be used for a linear guide bearing device. <P>SOLUTION: As a cross-section of a guide rail 104 is a U-shape, external surfaces of side walls 104a, 104a and a bottom wall 104b consist of flat surfaces, the actuator has an advantage that it is easy to enhance working accuracy (especially straight accuracy). With a toothed belt 111 positioned from upside in the guide rail 104 of which cross section is the U-shape, it is possible to point a closed lower side of the guide rail 104 to a work W, suppress the dust generated from the toothed belt 111 from adhering to the work W and reduce cost without a need to provide a cover additionally. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an actuator suitable for use in, for example, a linear guide bearing device such as a manufacturing apparatus, an inspection apparatus, or a conveyance apparatus.

For example, in a manufacturing apparatus or the like, a linear guide bearing device is used to drive an object such as a workpiece. In Patent Document 1, an endless belt is connected to the side on which the main bearing is attached on the opposite side of the drive pulley and the driven pulley, and is provided with a counter bearing movable along the counter guide rail. Is disclosed. In this prior art, by moving the main bearing and the counter bearing in the opposite directions, it is possible to suppress the reaction force of the main bearing that occurs during acceleration or deceleration, thereby suppressing vibration.
JP 2001-248703 A

  By the way, in the actuator of patent document 1, since the guide rail is a round shaft, since the main bearing engaged with it is cylindrical, there exists a problem that it is difficult to ensure straightness accuracy. Further, since the endless belt is in an open state, there is a problem that dust generation or the like is likely to occur.

  Therefore, the present invention has been made in view of the problems of the prior art, and is preferably used for a linear guide bearing device that can ensure high straightness accuracy with high acceleration / deceleration and suppress dust generation and vibration. It is an object to provide a simple actuator.

In order to achieve the above object, the actuator of the present invention comprises:
A drive pulley that is rotationally driven by a drive device;
A driven pulley supported rotatably;
An endless belt stretched between the drive pulley and the driven pulley;
A guide rail,
A main bearing connected to the endless belt and movable along the guide rail;
Counter guide rail,
A counter bearing connected to the endless belt on the opposite side of the pulley to the side on which the main bearing is attached, and movable along the counter guide rail;
A cross-section of the guide rail is U-shaped, and the endless belt is disposed inside the guide rail.

  According to the actuator of the present invention, a driving pulley that is rotationally driven by a driving device, a driven pulley that is rotatably supported, the endless belt that is spanned between the driving pulley and the driven pulley, and a guide A rail, a main bearing connected to the endless belt and movable along the guide rail, a counter guide rail, and a side on which the main bearing is attached to the endless belt sandwich the pulleys. The counter bearing is connected on the opposite side and is movable along the counter guide rail, so that the main bearing and the counter bearing can be moved in the opposite directions so as to accelerate or decelerate. The reaction force of the main bearing that occurs can be suppressed, thereby suppressing vibration. In this case, the closer the mass of the main bearing and the workpiece attached thereto to the mass of the counter bearing, the more effective.

  Furthermore, since the cross section of the guide rail is U-shaped, and the outer surface thereof is a combination of flat surfaces, there is an advantage that machining accuracy (particularly straightness accuracy) can be easily improved. Further, by arranging the endless belt inside the open side of the guide rail having a U-shaped cross section, when the closed side of the guide rail is directed to the work, the endless belt is moved from the endless belt to the work. The generated dust can be prevented from adhering, and it is not necessary to provide a separate cover, thereby reducing the cost.

  It is preferable that the endless belt is connected to the main bearing at the position of the center of gravity, because an unnecessary moment can be suppressed. It should be noted that “the center of gravity position of the main bearing” refers to the center of gravity position of the combination of the main bearing and another object when another object is mounted on the main bearing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1 is a top view of a linear guide bearing device 100 including an actuator according to the present embodiment, FIG. 2 is a side view, and FIG. 3 is an arrow cut along the line III-III in FIG. It is the enlarged view seen in the direction. The drive pulley 109, the driven pulley 110a, the toothed belt 111 as an endless belt, the guide rail 104, the main bearing 120, the counter guide rails 131 and 131, and the counter bearing 130 constitute an actuator.

  As shown in FIGS. 1 and 2, support plates 102 and 103 are fixed to both ends of the guide rail 104 that also functions as a frame. Round shaft-shaped counter guide rails 131 and 131 are arranged in parallel to the guide rail 104 so as to be stretched over the rail support plates 102 and 103.

  The motor 108 is attached to the right rail support plate 103 in FIGS. 1 and 2 in a state where the rotating shaft 108 a protrudes horizontally and in a direction perpendicular to the axis of the guide rail 104. A toothed drive pulley 109 is attached to the rotary shaft 108a. 1 and 2, a left side rail support plate 102 is provided with a pulley housing 110 that rotatably supports a toothed driven pulley 110a. A toothed belt 111 is stretched between the drive pulley 109 and the driven pulley 110 a in a direction along the guide rail 104. Therefore, the rail support plates 102 and 103 have openings necessary for passing the toothed belt 111.

  A part of the toothed belt 111 is attached to the main bearing 120 by a bent plate-shaped fixture 121. The main bearing 120 includes the guide rail 104. This configuration will be described more specifically.

  In FIG. 3, the guide rail 104 has a U-shaped cross section in which the lower ends of a pair of side walls 104a and 104a are connected by a bottom wall 104b. The main bearing 120 connects a bottom plate 120a facing the bottom wall 104b, side plates 120b and 120b facing the side surfaces of the side walls 104a and 104a, and top plates 120c and 120c facing the top surfaces of the side walls 104a and 104a, respectively. Is formed. Static pressure pads SP formed of porous graphite are disposed on each surface of the bottom plate 120a, the side plates 120b and 120b, and the top plates 120c and 120c facing the guide rail 104. Compressed air is supplied to the static pressure pad SP from an air source (not shown), and the main bearing 120 is slightly separated from the guide rail 104 by the pressure of the gas discharged from the static pressure pad SP toward the guide rail 104. So that it can move almost without friction.

  Both ends of the fixture 121 are attached to the top plates 120c, 120c of the main bearing 120 by bolts (not shown). The fixing device 121 is bent so that the center is lowered by one step, and the toothed belt 111 is fixed to the lowered center portion. The toothed belt 111 attached to the fixture 121 is disposed at a position lower than the upper ends of the side walls 104 a and 104 a of the guide rail 104, that is, disposed inside the guide rail 104. By setting the connecting position of the toothed belt 111 and the fixture 121 to the position of the center of gravity of the main bearing 120, it is possible to suppress generation of unnecessary moments in the main bearing 120 when driven by the toothed belt 111.

  On the other hand, a part of the toothed belt 111 is attached to the counter bearings 130 and 130 by a fixture 132 similar to the fixture 121 at a position facing the drive pulley 109 and the driven pulley 110a. The counter bearings 130 and 130 have a rectangular parallelepiped shape having a cylindrical hole through which the counter guide rails 131 and 131 are inserted. Circular cylindrical static pressure pads SP and SP are arranged in the cylindrical hole. The pressure of gas discharged from the static pressure pads SP, SP toward the counter guide rails 131, 131 is supplied to the static pressure pads SP, SP formed of graphite porous by compressed air from an air source (not shown). As a result, the counter bearings 130 and 130 are slightly separated from the counter guide rails 131 and 131, and can move without friction.

  The counter guide rails 131 and 131 are intended to guide the counter bearings 130 and 130 for balancing the mass with respect to the main bearing 120, and therefore are not required to be very accurate. A round shaft that can be used. However, if there is only one counter guide rail 131, the counter bearing 130 will rotate, so that two counter bearings 130, 130 that are arranged in parallel and engaged with each other are connected by a fixture 132, Restricted to movement in the axial direction only. By setting the connecting position of the toothed belt 111 and the fixture 132 to the position of the center of gravity of the counter bearings 130 and 130, it is possible to generate unnecessary moments in the counter bearings 130 and 130 when driven by the toothed belt 111. Can be suppressed.

  As a means for balancing the mass, another balance weight may be mounted on the counter bearings 130 and 130. For example, the main bearing 120 is made of an aluminum alloy having a small specific gravity, and the counter bearings 130 and 130 are, on the other hand, specific gravity. If it is designed by using a large iron-based material, it is possible to balance without adding a balance weight. As a result, a reaction force during acceleration on the counter bearings 130 and 130 is not generated as a moment load, so that the bearings can be small.

  The operation of this embodiment will be described. An inspection camera (not shown) is attached to the lower surface of the main bearing 120 so that the upper surface of the workpiece W (FIG. 2) can be scanned. First, the main bearing 120 is slightly separated from the guide rail 104 by compressed air supplied from an air source (not shown), and the counter bearings 130 and 130 are slightly separated from the counter guide rails 131 and 131. Maintained in a state.

  Here, when the motor 108 drives the drive pulley 109, the main bearing 120 is almost free of friction along the guide rail 104 via the toothed belt 111, and the counter bearings 130, 130 with respect to the counter guide rails 131, 131 are. Is moved almost without friction. At this time, the driving reaction force generated at the time of acceleration or deceleration is canceled by counter bearings 130 and 130 provided facing the main bearing 120 so that vibration can be suppressed. If the mass of the main bearing 120 (and the object mounted on it) and the total mass of the counter bearings 130 and 130 are substantially matched, the driving reaction force can be more effectively offset and vibration can be effectively performed. Can be suppressed. The drive pulley 109 and the driven pulley 110a are the largest dust generation sources of this device, but as a countermeasure, a cover C (dotted line in FIG. 1) is provided, and the inside is connected to an exhaust pump (not shown). As a result, dust collection exhaust is performed. As a result, it is possible to realize a suitable actuator that has very little foreign matter attached to the workpiece W even when operated at high speed and high acceleration / deceleration.

  According to the present embodiment, the cross section of the guide rail 104 is U-shaped, and therefore the outer surfaces of the side walls 104a and 104a and the bottom wall 104b are flat surfaces, so that it is easy to improve processing accuracy (particularly straightness accuracy). There are advantages. Further, by disposing the toothed belt 111 inside the guide rail 104 having an U-shaped cross section from the open upper side, the closed lower side of the guide rail 104 can be directed to the work W. The dust generated from the toothed belt 111 can be prevented from adhering, and it is not necessary to provide a separate cover, thereby reducing the cost.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. The main bearing 120 can be mounted not only with a camera but also with various objects and processing devices.

It is a top view of the linear guide bearing apparatus 100 containing the actuator concerning this Embodiment. It is a side view of the linear guide bearing apparatus 100 containing the actuator concerning this Embodiment. FIG. 3 is an enlarged view of the configuration of FIG. 1 taken along line III-III and viewed in the direction of the arrow.

Explanation of symbols

100 linear guide bearing device 102, 103 rail support plate 104 guide rail 104a side wall 104b bottom wall 108 motor 109 driving pulley 110 pulley housing 110a driven pulley 111 belt 120 main bearing 120a bottom plate 120b side plate 120c top plate 121 fixing tool 130 counter bearing 131 counter guide Rail 132 Fixing tool C Cover SP Static pressure pad W Workpiece

Claims (2)

A drive pulley that is rotationally driven by a drive device;
A driven pulley supported rotatably;
An endless belt stretched between the drive pulley and the driven pulley;
A guide rail,
A main bearing connected to the endless belt and movable along the guide rail;
Counter guide rail,
A counter bearing connected to the endless belt on the opposite side of the pulley to the side on which the main bearing is mounted, and movable along the counter guide rail;
The guide rail has a U-shaped cross section, and the endless belt is disposed inside the guide rail.   The actuator according to claim 1, wherein the endless belt is connected to the main bearing at a center of gravity position.

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