JP3630602B2 - Reciprocating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reciprocating device applied to a reciprocating device such as an optical head in OA equipment, a reciprocating mechanism such as a work table in a precision machine tool, and the like.
[0002]
[Prior art]
As the reciprocating device, a belt type moving device using a timing belt and a servo motor (stepping motor) and a ball screw type moving device using a ball screw and a servo motor are generally used. The belt-type moving device engages a timing belt with a moving object that is linearly reciprocated in a fixed section, and reciprocates the moving object by reciprocating the timing belt on a fixed track with a servo motor. The ball screw type moving device reciprocates the moving object by engaging a nut or the like fixed to the moving object with a screw thread or a screw groove having an equal pitch of the ball screw and rotating the ball screw forward and backward by a servo motor. .
[0003]
In these reciprocating devices, the reciprocating speed of the moving object in a fixed section is adjusted by automatically controlling the moving speed of the timing belt and the rotating speed of the ball screw by the speed control circuit built in the servo motor. Yes. For example, a moving object that reciprocates in a fixed section moves to one end of the fixed section, stops once, and then starts moving in the opposite direction. In order to reduce the influence of the inertial force that is applied when the moving direction is reversed. In addition, the speed control circuit of the servo motor automatically controls so that the moving speed gradually decreases when the moving object approaches the end of the fixed section. Also, in applications where the moving object is moved at high speed in some sections of the fixed section and moved at low speeds in other sections, is the servo motor speed control circuit configured to support this application? A command signal for changing the speed is given to the speed control circuit.
[0004]
[Problems to be solved by the invention]
The reciprocating device using the servo motor as described above is used as a high-performance device for various applications because the moving speed of the moving object that reciprocates in a fixed section can be adjusted arbitrarily and with high accuracy. The servo motor is expensive because of the speed control circuit required to variably adjust the moving speed of the object to be moved, and the entire motor becomes large. For this reason, the reciprocating device itself is expensive because of the servo motor, making it difficult to reduce the cost of equipment products such as OA equipment incorporating the reciprocating device. Also, when the servo motor variably adjusts the moving speed of the moving object in the fixed section, the position of the moving object in all the fixed sections is detected one by one, and the detection signal is fed back to the speed control circuit of the servo motor. In this case, it is usual to prevent malfunction of speed control. In this case, the detection means such as an optical sensor for detecting the position of the moving object in a fixed section one by one, or the detection of this detection means A protection circuit for preventing troubles due to mistakes is required, and the reciprocating device is still more expensive and larger.
[0005]
Instead of the servo motor, a reciprocating device using a drive motor that only reciprocates at a constant speed is also used for OA equipment. This moving device is inexpensive and small because the drive motor that rotates at a constant speed is not equipped with a speed control circuit, so it does not have the problems associated with the servo motor, but almost all sections in the fixed section of the moving object. Since the movement speeds at the same time are the same, the content of work performed by reciprocating the object to be moved in a fixed section is limited and there is a problem of lack of versatility. Further, if the moving object is moved at a high speed in a fixed section, it is suddenly stopped when it is temporarily stopped at the end of the fixed section, and there is a problem that a large inertial force acts on the moving object during this sudden stop.
[0006]
Therefore, an object of the present invention is to provide an inexpensive and small reciprocating device capable of freely adjusting the reciprocating speed of a moving object without using a servo motor.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a feed shaft member that has an uneven spiral body on the outer periphery and reciprocates around an axis, a drive motor that reciprocates the feed shaft member at a fixed position, and a feed shaft member Guide means arranged in parallel with the guide means, supported by the guide means so as to be reciprocable in the axial direction of the feed shaft member, and extending in the direction of the feed shaft member from the guide means to the spiral body of the feed shaft member in its spiral direction In the reciprocating device having the moving body having the engaging means that slidably engages with the feed shaft member, the pitch of the spiral body of the feed shaft member is made different in the axial direction of the feed shaft member, and the spiral body of the feed shaft member is It is characterized in that it is a strip wound in a convex shape with a different pitch on its outer periphery, and the engaging means of the moving body is a bifurcated claw member that sandwiches the strip .
[0008]
Here, the spiral body of the feed shaft member is a spiral protrusion having a constant width, and the pitch between adjacent portions of the spiral body at 360 ° is different. When the feed shaft member is reciprocally rotated by the drive motor, the moving body is reciprocated by the ball screw method through the engagement means of the spiral body and the moving body, and the moving speed at this time depends on the pitch of the spiral body of the feed shaft member and the feed shaft member. Determined by the rotation speed. When the feed shaft member is rotated at a constant speed, the moving speed of the moving body can be determined at a variable speed only by the pitch of the spiral body. In this case, the drive motor that rotates the feed shaft member at a constant speed is not equipped with a speed control circuit. A small motor can be used.
[0009]
Further, it is possible to connect the engaging means of the moving body that engages with the spiral body of the feed shaft member so as to be able to swing and swing with respect to the mobile body in a direction that reduces sliding resistance with the spiral body. It is desirable to make the frictional engagement state between the helical body and the moving body engaging means having different pitches always stable.
[0010]
Further, the spiral body of the feed shaft member is a strip wound in a convex shape with a different pitch on the outer periphery of the core rod, so that a feed shaft member having a spiral body with a different pitch can be manufactured at low cost. Desirable above.
[0011]
Further, if the strip is wound around the outer periphery of the core rod of the feed shaft member so as to be movable in the axial direction of the feed shaft member, the pitch of the spiral body of the feed shaft member can be arbitrarily changed to The moving speed can be changed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments will be described with reference to FIGS. Note that the same or corresponding parts are denoted by the same reference numerals throughout the drawings.
[0013]
A reciprocating device shown in one embodiment of FIG. 1 is arranged in parallel to a linear feed shaft member 1, a drive motor 10 that reciprocally rotates the feed shaft member 1 around its axis, and the feed shaft member 1. The guide means 20 is provided, and the moving body 30 is supported by the guide means 20 being guided in the moving direction. A moving object (not shown) is connected to the moving body 30, and the reciprocating movement is controlled linearly in a fixed section.
[0014]
The feed shaft member 1 is formed by, for example, winding a long strip 4a spirally around the outer periphery of a core rod 3, which is a single linear metal round bar, and projecting on the outer periphery of the core rod 3 with the strip 4a. The helical body 2a is formed, and the pitch P of the helical body 2a is made different as will be described later. The strip 4a is, for example, a spiral component 5 in which a strip-shaped steel plate having a constant lateral width w and thickness t as shown in FIGS. 2 and 3 is spirally wound in the width direction. Such a spiral component 5 can be applied to a commercially available mini-spirer (trade name of Suncor Co., Ltd.) and the like, and the feed shaft member 1 can be manufactured at low cost by this application. As shown in FIG. 3, the pitch P continuous in the axial direction of the strip-like strip 4a of the spiral component 5 is gradually different, and the core rod 3 is press-fitted into the spiral component 5 to fix the pitch P. It becomes. Both ends of the core rod 3 without the spiral body 2 a are rotatably supported by bearings 6, 6, the bearings 6, 6 are fixed to a flat plate-like fixed frame 7, and the feed shaft member 1 is supported in parallel to the fixed frame 7. Is done.
[0015]
The drive motor 10 is supported by the fixed frame 7 and is connected to one end of the core rod 3 of the feed shaft member 1 via the speed reduction mechanism 11. As the drive motor 10, an inexpensive and small motor that does not include a speed control circuit or the like is applied, which rotates the feed shaft member 1 at a constant speed in both forward and reverse directions. Although a servo motor such as a conventional reciprocating device can be applied to the drive motor 10, this application is unnecessary and uneconomical for the reason described later.
[0016]
The guide means 20 is a guide rod, a guide groove, a guide rail or the like parallel to the feed shaft member 1, and one linear guide rod 20 is shown in FIG. The moving body 30 is fitted to the guide rod 20 so as to be slidable in the axial direction. Both ends of the guide rod 20 are fixed to the support base 21, and the support base 21 is fixed to the fixed frame 7.
[0017]
The moving body 30 includes a cylindrical slider portion 31 that is slidably fitted to the guide rod 20, a connecting portion 32 that is integrated with the slider portion 31 and extends from the slider portion 31 toward the feed shaft member 1, The engaging means 33 is connected to the tip of the connecting portion 32. The engaging means 33 is engaged with a part of the spiral body 2a of the feed shaft member 1 so as to be slidable in the spiral direction of the spiral body 2a. When the spiral body 2a is a strip-like strip 4a, the engaging means 33 is engaged. Is a bifurcated claw member that clamps the strip 4a in the thickness direction. The engaging means 33 engages with the spiral body 4a of the feed shaft member 1 in the radial direction of the axis of the feed shaft member 1 and from a fixed direction in which the guide rod 20 is present. When the feed shaft member 1 rotates, the spiral body 4a rotates while being frictionally engaged with the engaging means 33, and the engaging means 33 is moved in the axial direction of the feed shaft member 1, and the moving body 30 is moved by this axial movement. It is guided by the guide rod 20 and moves linearly.
[0018]
As shown in FIG. 1, for example, the pitch P of the spiral body 2a of the feed shaft member 1 has a maximum pitch Pa at the center portion of the feed shaft member 1, and the pitch gradually decreases from the center portion to both end portions. The pitches Pb of the portions are different so as to be minimized. As shown by the solid line in FIG. 1, the feed shaft member 1 is moved in the forward direction by the drive motor 10 in a state where the engaging means 33 of the moving body 30 is engaged with the spiral body 2 a of the center portion of the feed shaft member 1 (FIG. 1 is rotated at a constant speed (in the direction of the solid line arrow 1), the moving body 30 starts linear movement in the right direction in FIG. The moving speed of the moving body 30 at the start of movement is proportional to the pitch Pa of the spiral body 2a with which the engaging means 33 is engaged because the rotation speed of the feed shaft member 1 is constant. Is the maximum, the pitch P becomes smaller as it moves, and the moving speed gradually decreases. When the moving body 30 moves to one end of the feed shaft member 1, the minimum moving speed is reached by the minimum pitch Pb. Further, if the feed shaft member 1 is rotated at a constant speed in the reverse direction (in the direction of the broken line arrow in FIG. 1) while the movable body 30 is at the position of the solid line in FIG. 1, the movable body 30 starts at the left direction in FIG. It moves linearly with a speed change pattern that gradually decreases.
[0019]
As described above, when the feed shaft member 1 is reciprocated by the constant speed rotation of the drive motor 10, the moving body 30 moves at a high speed at the center portion of the feed shaft member 1 and moves at a low speed at both ends. The moving speed of 30 can be arbitrarily changed. When the moving body 30 moves to a fixed position near both ends of the guide rod 20, it is desirable to install switches 22, 22 such as limit switches that detect the position and output an electrical signal on the fixed frame 7. . The rotation of the feed shaft member 1 is temporarily stopped by the detection signals of the switches 22 and 22, the linear movement of the moving body 30 is temporarily stopped, and then the moving direction is reversed.
[0020]
Such a temporary stop of the moving body 30 can be smoothly performed without receiving a large inertia force because the moving speed immediately before the stop is the minimum low speed with the minimum pitch Pb. Further, since the moving body 30 can be moved at a high speed in the central portion of the feed shaft member 1, various operations can be performed at a high speed by the moving object that reciprocates linearly with the moving body 30. Furthermore, the drive motor 10 of the drive source that moves the moving body 30 while changing the speed only rotates at a constant speed. Therefore, an inexpensive and small-sized motor equipped with a rotation on / off switch circuit can be used. Further, the moving speed at each position within a moving section (corresponding to a fixed section between the pair of switches 22 and 22) determined between both ends of the guide rod 20 of the moving body 30 is the helical body 2a of the feed shaft member 1. Therefore, it is not necessary to detect the position of the moving body 30 in every section of the moving section, and the moving speed in the entire moving section of the moving body 30 can be controlled with high accuracy.
[0021]
Next, more specific embodiments of the present invention will be described in order with reference to the drawings.
[0022]
As shown in the embodiment of FIG. 1, when the feed shaft member 1 is configured by winding a strip-like strip 4a around a round bar-shaped core bar 3 in a spiral manner with a different pitch, the cross-sectional view of FIG. As shown in FIG. 4, the strip-like strip 4a is inclined with respect to the outer periphery of the core rod 3, and the inclination angle θ is proportional to the pitch of the strip 4a. Therefore, the engaging means 33 of the moving body 30 to be engaged with the strip 4a is connected to the connecting portion 32 of the moving body 30 so as to be swingable in the axial direction of the feed shaft member 1, and the engaging means 33 is connected. Is inclined to follow the change of the inclination angle θ of the strip 4a with which the engagement is made. In this way, the engaging means 33 always engages in a stable state parallel to the strip 4a even if the inclination angle θ of the strip 4a changes, and has low friction resistance without falling into the strip 4a. It comes to slide. Further, by installing the engaging means 33 so as to be swingable in this manner, the spiral body 2a of the feed shaft member 1 is a strip-like strip 4a, that is, a commercially available and inexpensive spiral shown in FIG. The component 5 can be used.
[0023]
4 (A) and 4 (B) show a modification of the engaging means 33. A pair of rollers 34, 34 can be freely rotated by a bifurcated engaging means 33 that sandwiches the strip-like strip 4a. Incorporating, the pair of rollers 34 and 34 are caused to roll on both sides of the strip 4a. Thus, the smooth engagement state of both can be ensured by slidingly moving the engaging means 33 along the strip 4a via the rollers 34, 34.
[0024]
In the embodiment of FIG. 5, a round rod-shaped wire rod 4 b is wound around the outer periphery of the core rod 3 of the feed shaft member 1 at a different pitch to form a convex spiral body 2 a. In this case as well, the engaging means 33 may be sandwiched between the rods 4b of the round bar wire, and both may be slidably engaged. A spiral spring wire that is a commercially available product and is inexpensive can be applied to the spiral strip 4b of such a round bar wire.
[0025]
FIG. 6 shows an example of changing the shape of the spiral body 2 b of the feed shaft member 1. The spiral body 2b is a spiral groove formed by cutting the outer periphery of the cylindrical core rod 3 in a spiral manner. The width of the spiral groove 2b is constant, and the pitch P between the grooves is different. The engaging means 33 is integrally provided with a protruding piece 33 ′ that is fitted into the spiral groove 2b and frictionally engages with both side walls of the spiral groove 2b. The formation of the spiral groove 2b may be performed by NC control in the manner of normal thread groove cutting.
[0026]
7A and 7B are modifications of the embodiment of FIG. That is, when the strip-like strip 4a of the embodiment of FIG. 2 is wound around the outer periphery of the core rod 3 with a different pitch P, it is fixed to the core rod 3 as it is, but without being fixed, it is spiral. FIG. 7 shows that the elastic force of the strip 4a is elastically coupled to the outer periphery of the core rod 3 so as to be axially movable. The strip 4a shown in FIG. 7A shows a pitch state similar to that in FIG. 2, and the pitch is changed by moving the strip 4a in the axial direction while being in elastic contact with the core rod 3. 7 (B). Thus, by making it possible to arbitrarily change the pitch P of the spiral body 2a in one feed shaft member 1, it becomes possible to reciprocate the moving body 30 with more various movement speeds with one feed shaft member 1, In addition, the moving speed of the moving body 30 can be changed at the use stage of the reciprocating device.
[0027]
FIGS. 8 to 10 show modifications of the pitch form of the spiral body 2 a in one feed shaft member 1. That is, the feed shaft member 1 in FIG. 1 has a pitch configuration in which the pitch Pa is maximized at the center and the pitch Pb is minimized at both ends, whereas FIG. 8 is a pitch Pc at the center of the feed shaft member 1. Is minimized, and the pitch Pd at both ends is maximized. Further, the feed shaft member 1 shown in FIG. 9 minimizes the pitch Pe at one end, and expands the pitch toward the other end to maximize the pitch Pf at the other end. The pitch form of the feed shaft member 1 shown in FIGS. 8 and 9 is determined according to the request for the moving speed in the fixed section of the moving body 30. Further, such selection of the pitch form can be executed by one feed shaft member 1 if the pitch can be changed on the core rod 3 of the strip 4a as in the embodiment of FIG.
[0028]
In the embodiment of FIG. 10, a long strip 4 a is spirally wound around the outer periphery of one core rod 3 in the longitudinal direction, and then the strip 4 a is continued as it is. A spiral body 2a ′, 2a ″ having opposite spiral directions is formed on both sides from the central portion of the core rod 3 by winding it around the outer periphery of the half, and the spiral bodies 2a ′, 2a ″ are independent of each other. Two moving bodies 30 ′ and 30 ″ are engaged. The pitch form of each of the spiral bodies 2a ′ and 2a ″ is such that the pitch Pg on the center side of the feed shaft member 1 is small and the pitch Ph on both ends is large. Is set. When the feed shaft member 1 is reciprocally rotated, the pair of moving bodies 30 ′ and 30 ″ move at the same time with the same speed changes in opposite directions.
[0029]
【The invention's effect】
According to the present invention, when the feed shaft member is reciprocally rotated at a constant speed by the drive motor, the movable body reciprocates at different speeds according to different pitches of the spiral of the feed shaft member. Moving speed can be controlled only by the pitch of the spiral of the feed shaft member, such as moving at a high speed in the section or moving at a low speed at a predetermined stop position of the moving body, and setting of various moving speeds of the moving body is possible. It is possible to provide a reciprocating device with high performance and excellent versatility. Also, since the moving speed of the moving body can be controlled by rotating the feed shaft member at a constant speed, the drive motor for reciprocatingly rotating the feed shaft member is not equipped with a speed control circuit. It can be applied, and the cost and size of the reciprocating device can be easily reduced.
[0030]
Further, the spiral member of the feed shaft member is formed by a convex strip, and the engaging means of the moving member is engaged with the strip so as to be able to swing and swing, whereby the engaging means is provided on the spiral strip. Sliding smoothly without twisting, the reciprocating motion of the moving body is stabilized.
[0031]
Further, by forming a spiral body by winding a strip around the outer periphery of the core rod, it becomes easy to manufacture feed shaft members having different pitches, and it is possible to reduce manufacturing costs.
[0032]
In addition, by winding the strip around the outer periphery of the core bar so that the pitch can be changed, it is possible to change various moving speeds of the moving body with a single feed shaft member, increasing the versatility and added value of the reciprocating device. Can be increased.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part of a reciprocating device showing a first embodiment of the present invention.
2 is a partial enlarged cross-sectional view of the apparatus of FIG.
3 is an exploded perspective view of a feed shaft member in the apparatus of FIG. 1. FIG.
4A is a partial cross-sectional view showing a second embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along line XX of FIG. 4A.
FIG. 5 is a partial plan view including a partial cross section showing a third embodiment of the present invention.
FIG. 6 is a partial plan view including a partial cross section showing a fourth embodiment of the present invention.
7A is a partial cross-sectional view showing a fifth embodiment of the present invention, and FIG. 7B is a partial cross-sectional view when the pitch is changed by moving the strip of FIG. 7A.
FIG. 8 is a partial plan view of an essential part showing a sixth embodiment of the present invention.
FIG. 9 is a partial plan view of an essential part showing a seventh embodiment of the present invention.
FIG. 10 is a partial plan view of a main part showing an eighth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Feed shaft member 2a Spiral body 2b Spiral body P Pitch of helical body 3 Core rod 4a Strip (band shape)
4b strip (round bar shape)
5 Helical component 10 Drive motor 20 Guide means, guide rod 30 Moving body 33 Engaging means

Claims (3)

A feed shaft member having an uneven spiral body on the outer periphery and reciprocatingly rotating around an axis; a drive motor for reciprocatingly rotating the feed shaft member at a fixed position; and guide means arranged in parallel with the feed shaft member; An engagement that is supported by the guide means so as to be reciprocally movable in the axial direction of the feed shaft member, and that engages with a spiral body of the feed shaft member slidably in the spiral direction at a tip extending from the guide means in the direction of the feed shaft member. In a reciprocating device provided with a moving body having means,
The pitch of the spiral of the feed shaft member is different in the axial direction of the feed shaft member;
The spiral body of the feed shaft member is a strip wound in a convex shape with a different pitch on the outer periphery of the core rod,
The engaging means of the moving body is a bifurcated claw member that sandwiches the strip.
A reciprocating device characterized by that. 2. The reciprocating device according to claim 1, wherein the strip is a spiral part formed by bending a long strip having a constant lateral width and a constant plate thickness into a spiral shape in the width direction. 3. The reciprocation according to claim 2, wherein engaging means of the moving body that engages with the spiral body of the feed shaft member is connected to the moving body so as to be able to swing in a direction that reduces sliding resistance with the spiral body. Mobile device.

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