JP6923783B2 - Work transfer device - Google Patents

Description

The present invention relates to a work transfer device that conveys a work by a traveling wave.

Conventionally, as a device for transporting parts, a parts feeder for transporting parts by vibrating the entire transporting portion in an oblique direction using a spring and a drive source has been known. In such a transport device, it is possible to increase the transport speed of parts by increasing the amplitude, but when the horizontal amplitude at the downstream end of the transport section increases, the interface section set at the downstream end of the transport section It is necessary to widen the gap between the equipment and the next process equipment. As a result, parts may fall between the next process equipment and the interface portion, or parts may be clogged. In particular, as the miniaturization of parts and the increase in transport speed progress, the probability that parts will fall or become clogged increases.

Further, in the above-mentioned parts feeder, it is possible to increase the transfer speed of the work by increasing the frequency of the drive source that vibrates the entire transfer portion in an oblique direction and reducing the displacement amplitude, but generally about 300 Hz. When the frequency of the drive source is raised further, the frequency approaches the frequency of 1 kHz to 4 kHz, which is highly sensitive to the human ear, and the noise becomes louder. Further, in the structure of resonating with a leaf spring, when the frequency exceeds 300 Hz and exceeds 1 kHz, the transport portion or the like is elastically deformed and the work cannot be normally transported (it is difficult to uniformly vibrate the transport portion (chute) in parallel). become).

As a parts feeder that can avoid the occurrence of such a defect, a parts feeder that transfers parts by using a traveling wave generated by ultrasonic vibration is known. In Patent Document 1, a ring (including an elliptical ring) or a disk-shaped vibrating body installed at an angle with respect to a horizontal plane has a polarization direction on the back surface at 1/2 wavelength of a standing wave. A piezoelectric body having a large number of polarization regions that repeat positive and negative alternately is attached, and two types of high-frequency voltages (high frequencies with different temporal phases) that are 90 ° out of phase in time are attached to each of the two polarization region groups of the piezoelectric body. By applying a voltage), a traveling wave is excited by the bending vibration of the piezoelectric body, and a configuration is disclosed in which a component on the vibrating surface of the vibrating body is transferred. Further, the patent document also discloses a configuration in which a plurality of slits are provided on the transport surface at a predetermined pitch along the transport direction for the purpose of increasing the transport speed.

Japanese Unexamined Patent Publication No. 6-127655

By the way, in an ultrasonic parts feeder in which a transport portion having a large number of slits formed in the transport portion is vibrated by ultrasonic drive to transport a workpiece, when the slits are deepened in order to increase the transport speed, a comb-teeth shape is formed. Local unintended behavior (vibration) occurs at the protruding portion of the work, which causes the work to jump and hinder the smooth transfer process. And, such a problem becomes more remarkable as the drive frequency is increased. According to the present inventor, such a problem does not occur in a work transfer device of a type in which the entire transfer portion is vibrated diagonally by the vibration of a spring, and a traveling wave is generated by elastically vibrating the transfer portion as in Patent Document 1. It was found that it occurs in the work transfer device.

Therefore, solutions such as making the slits shallower and widening the distance between the slits can be considered, but there are problems such as a decrease in the transport speed and a high ratio of standing waves making it difficult to generate traveling waves. .. It has been found by the studies of the present inventors that such a problem is the same even when a slit is not formed in the transport portion, for example, when the transport portion is constructed by using materials having different elastic moduli.

The present invention has been made by paying attention to such a point, and a main object thereof is to prevent / suppress a situation in which local vibrations that hinder smooth transport processing are generated on the transport surface. At the same time, it is an object of the present invention to provide a work transfer device capable of increasing the transfer speed.

That is, the present invention includes a transport portion in which a transport surface is formed in at least a part of an outer peripheral portion which is a region along the outer peripheral edge, and a driving means for generating a traveling wave in the transport portion, and the work is transported by the traveling wave. In the work transfer device to be conveyed above, the transfer portion is formed by an elastic body which is an elastic member that generates a traveling wave, and the transfer surface is formed by a single elastic body. However, with respect to the cross-sectional shape cut with a vertical cross section orthogonal to the transport surface that crosses the transport surface, the wall thickness of the region on the outer peripheral side including the transport surface in the vertical direction is the wall thickness of the region inside the transport surface in the horizontal direction. the stiffness of the outer peripheral side region of der I and vertically those formed to be greater than, set as stiffness toward the neutral axis becomes gradually larger in the transport unit from the region where the conveying surface is formed It is characterized in der Rukoto those.

The present inventor sets the cross-sectional shape of the transport portion relative by setting the wall thickness of the outer peripheral region including the transport surface in the vertical direction to be larger than the wall thickness of the inner region in the horizontal direction with respect to the transport surface. It was found that local vibration is less likely to occur in the outer peripheral region where the wall thickness is large. Further, in the outer peripheral region where the wall thickness is relatively large, the position where the material is not subjected to any load from the transport surface when a traveling wave is generated on the transport surface to the neutral axis (when a bending moment is applied). The distance (e value) to the position (position where neither tension nor compression is generated) can be maintained at a value relatively large in the horizontal direction with respect to the transport surface as compared with the region inside the transport surface, and the amplitude in the transport direction can be maintained. Can be increased and the transport speed can be increased.

Suitable transport portions in the work transport device according to the present invention include those in which the outer peripheral portion including the transport surface is formed so as to protrude upward or downward from the region inside the transport surface. Examples thereof include those formed so that the wall thickness gradually or gradually decreases from the outer peripheral portion including the transport surface to the region inside the outer peripheral portion.

In the present invention, the region on the upper surface side of the outer peripheral portion including the transport surface of the transport portion is composed of a low elastic modulus material, and the other region is composed of a high elastic modulus material having a higher elastic modulus than the low elastic modulus material. In this case, the neutral shaft can be lowered to the bottom surface side of the transport portion as compared with the embodiment in which the entire transport portion is made of the same material, and the transport surface to the neutral shaft when a traveling wave is generated on the transport surface. By increasing the distance (e value), improving the transport speed, and forming the region on the upper surface side of the outer peripheral portion including the transport surface with a material having a low elastic modulus, it is possible to suppress the jumping of the workpiece during the transport process. Is. Examples of the high elastic modulus material include metal and the like, and examples of the low elastic modulus material include resin and the like.

Further, in the present invention, a transport surface formed so as to form a groove that opens upward on the upper surface side of the transport portion is applied, and a large number of slits orthogonal to the transport surface are provided on the outer peripheral portion of the transport portion. It is possible to adopt a configuration in which the slit is formed so as to be deeper than the groove shape of the transport surface and not reach the bottom surface of the transport portion, and is open to the upper side and the outer peripheral edge of the transport portion. By forming a large number of such slits on the outer peripheral portion of the transport portion, the transport portion has a comb-shaped transport surface, and the speed of the work to be transported on the transport surface can be further increased. Since the slits are formed on the transport surface, the neutral axis is lowered as compared with the configuration in which the slits are not formed on the transport surface, so that from the transport surface to the neutral axis when a traveling wave is generated on the transport surface. The distance (e value) increases and the transport speed improves.

As a specific application example of the work transfer device according to the present invention, there may be a so-called linear feeder provided with a transfer surface as a return path in addition to the transfer unit for transporting the work to the next process. That is, the transport portion is composed of two straight portions parallel to the transport surface and a U-turn portion connecting these two straight portions in a region closer to the inside than the transport surface (convey surface of the main truck). It is a work transfer device forming a return surface to be returned.

The "transport surface" in the present invention includes any of a horizontal or substantially horizontal surface (horizontal plane), a surface inclined at an inclination angle with respect to the horizontal (inclined surface), or a U-shaped surface (curved surface). It is a concept to do. Further, as the work, for example, a minute part such as an electronic part can be mentioned, but an article other than the electronic part may be used.

According to the present invention, in order to transport the work on the transport surface by the traveling wave generated on the transport surface, a gap in consideration of the horizontal amplitude between the interface portion set at the downstream end of the transport portion and the next process equipment. It is not necessary to secure the space, and it is possible to prevent and suppress the drop or clogging of the work that may occur when the gap is widened, and the cross-sectional shape of the transport portion is the region on the outer peripheral side including the transport surface in the vertical direction. By setting the wall thickness to be larger than the wall thickness of the inner region in the horizontal direction with respect to the transport surface, the traveling wave generated on the transport surface enables the workpiece to be transported more smoothly and at higher speed than before. A possible work transfer device can be provided.

The whole view of the work transfer apparatus which concerns on one Embodiment of this invention. The schematic view which looked at the transport part of the linear feeder which concerns on the same embodiment from the bottom (back side). The overall block diagram of the linear feeder which concerns on this embodiment. The plan view of the linear feeder which concerns on the same embodiment. The figure which shows by omitting a part of the cross section of xx line of FIG. FIG. 6 is a diagram of a linear feeder including an arrow view in the B direction of FIG. The external view of the transport section in the same embodiment as viewed from below (back surface). FIG. 4 is an enlarged view of region C in FIG. 4 of the transport unit in the same embodiment. The figure which shows the spatial phase difference of the wave of 0 ° mode and 90 ° mode in the same embodiment. Explanatory drawing about rigidity and mass of the transport part in the same embodiment. The schematic diagram which shows the elastic deformation of the transport part which has a slit with time. The schematic diagram which shows the elastic deformation of the transport part without a slit with time. The figure which shows the linear feeder to be compared with the linear feeder which concerns on the same embodiment. The figure which shows typically the side cross section of the bowl feeder which concerns on the same embodiment. The figure which shows one modification of the linear feeder which concerns on the same embodiment.

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

The work transfer device according to the present embodiment is applied to, for example, the linear feeder LF and the bowl feeder BF shown in FIG. 1, respectively. The linear feeder LF will be described below. FIG. 2 is a schematic view of the linear feeder LF shown in FIG. 1 as viewed from below, and FIG. 3 is a diagram schematically showing the overall configuration of the linear feeder LF.

The linear feeder LF according to the present embodiment is connected to the bowl feeder BF for supply shown in FIG. 1, and as shown in FIG. 3, the plurality of driving means 4 are driven with a temporal phase difference. The work on the transport surface is transported by giving a signal.

As shown in FIG. 1, the linear feeder LF has a transport unit 1 having a transport surface, a support base 2 that supports the transport unit 1 from below, and a sorting unit 3 installed at a predetermined position of the transport unit 1. ..

The transport portion 1 is formed by a plate elastic body 11 which is an elastic member that generates a traveling wave, has a long shape, and has a shape asymmetrical with respect to an arbitrary axis. The plate elastic body 11 has, for example, a rectangular shape in a plan view, and is an elastic body in which a deflection wave is formed by vibration of, for example, 20 kHz or more. In this embodiment, the plate elastic body 11 of the conductor is applied. In the plate elastic body 11, the start end portion of the main track 16 described later in the transport portion 1 is connected to the end portion of the spiral track 16 (B) in the bowl transport portion 1 (B) of the bowl feeder BF. The transport unit 1 has a transport surface that extends substantially linearly. The shape of the transport unit 1 is not limited to a rectangular shape in a plan view, and may be an oval shape in a plan view as schematically shown in FIG.

1 and 4 to 8 (FIG. 4 is a plan view of the linear feeder LF, FIG. 5 is a schematic view showing a part of the cross section taken along line xx of FIG. 4, and FIGS. 6 (a) and 6 (a). (B) is an arrow view in the B direction and a cross-sectional view taken along the line B in FIG. 4, FIG. 7 is an overall view of the transport unit 1 as viewed from below, and FIG. As shown in the external view), a thin wall portion 12 having a substantially oval shape in a plan view having a uniform wall thickness dimension is formed in the central portion of the plate elastic body 11, and the outside of the thin wall portion 12 is a transport truck 13. It has become. As shown in FIG. 1, a flat holding plate 14 that is one size smaller than the thin-walled portion 12 is placed on the upward surface of the thin-walled portion 12, and a common fastener 15 is inserted into the screw insertion hole of the holding plate 14. The transport portion 1 is fixed to the support base 2 by passing through the screw insertion hole of the thin-walled portion 12 and screwing into the screw hole of the support base 2. In addition, in FIGS. 4 to 8, the pressing plate 14 and the fastener 15 are omitted, and in FIG. 5, the pressing plate 14 and the support base 2 are shown by an imaginary line (dashed line).

In the transport portion 1, the non-pinching portion of the thin-walled portion 12 that is not sandwiched between the pressing plate 14 and the support base 2 is more rigid than the sandwiching portion of the thin-walled portion 12 that is sandwiched between the pressing plate 14 and the support base 2. It is small and has low rigidity as compared with the transport truck 13. With such a configuration, the bending traveling wave can be effectively generated along the transport track 13 on the outer peripheral side of the plate elastic body 11 with respect to the non-pinching portion.

In the present embodiment, the linear main track 16 for aligning and transporting the workpieces is provided only in the area of the plate elastic body 11 on one side with the long axis L (see FIG. 4 and the like) as a boundary, and the main track 16 is provided. A return track 17 for returning the work removed from the bowl feeder BF to the bowl feeder BF is provided over a wide range from the area on one side of the plate elastic body 11 with the major axis L as a boundary to the area side on the other side.

As shown in FIG. 4, the return track 17 includes a linear upstream return track 17a provided inside the main track 16 in an area on one side of the plate elastic body 11 with the major axis L as a boundary, and a plate. A linear downstream return track 17b provided in the area on the other side of the elastic body 11 with the long axis L as a boundary, and an upstream end (end) of the downstream return track 17b from the downstream end (termination) of the upstream return track 17a. It is composed of a partial arc-shaped (U-shaped) intermediate return track 17c provided over the starting end). The upstream return track 17a and the downstream return track 17b are the "two straight portions parallel to the transport surface" in the present invention, and the intermediate return track 17 is the "U connecting the two straight portions" in the present invention. "Turn part".

As shown in FIG. 5, the return track 17 is set in a groove shape deeper than that of the main track 16. In the present embodiment, the upstream side return track 17a and the downstream side return track 17b are formed at positions symmetrical with respect to the long axis L of the plate elastic body 11. Further, the partial arc-shaped intermediate return track 17c is set to have a shape symmetrical with respect to the long axis L of the plate elastic body 11. The upward surface of the return track 17 is the "return surface" in the present invention. The return surface may be a horizontal or substantially horizontal surface (horizontal plane), a surface inclined at a predetermined angle with respect to the horizontal (inclined surface), or a U-shaped surface (curved surface).

The main track 16 is formed on the outer peripheral side of the upstream return track 17a in the area on one side of the plate elastic body 11 with the major axis L as a boundary, and has a groove shape whose cross-sectional shape is shallower than that of the upstream return track 17a. It is set (see FIG. 5). The upward surface of the main track 16 is the "conveying surface" in the present invention. The upward surface of the main track 16 is opened upward on the upper surface side of the transport unit 1, and in the present embodiment, the surface is set to a surface inclined by a predetermined angle so as to have a downward slope toward the outer peripheral side. In the main truck 16, the workpieces can be aligned in a row during transportation and supplied to the next process apparatus. In the following, the area on one side of the plate elastic body 11 with the long axis L as the boundary is referred to as the “main track side area”, and the area on the other side is referred to as the “return track side area”. The characteristic shape of the transport unit 1 according to this embodiment will be described later.

As shown in FIG. 1, the sorting unit 3 discriminates the transport posture of the work transported to the main truck 16, and ejects air based on the result of the posture discriminating and the sensor 31 used for the posture discriminating. It has an air ejection part (not shown). The sorting unit 3 receives air from the air ejection unit for the work transported on the transport surface of the main truck 16 with respect to the work that the sensor 31 determines to be in a posture (different direction posture) that is not the desired proper posture. By ejecting the work in a different direction, the work in a different direction is removed from the main track 16 and dropped onto the upstream return track 17a which is inside the main track 16 and at a lower position.

The work in the different direction, which is removed from the main track 16 and falls on the upstream return track 17a, is returned to the bowl elastic body 11 of the bowl feeder BF via the intermediate return track 17c and the downstream return track 17b. The work determined to be in the proper posture is discharged from the discharge port provided at the end of the main track 16.

As shown in FIGS. 2 and 3, the plurality of driving means 4 for bending and deforming the conveying portion 1 are composed of the piezoelectric element 41. Among the plate elastic bodies 11, the plurality of piezoelectric elements 41 that function as traveling wave generating means for generating traveling waves on the transport surface of the main track 16 and the return surface of the return track 17 are the transport surface of the main track 16 and the return track 17. It is attached to the back surface (downward surface) side of the portion where the return surface of the above is formed. The drive means 4 (piezoelectric element 41) is omitted in each of the drawings after FIG.

A plurality of piezoelectric elements 41 that generate a plurality of standing waves (first standing wave, second standing wave) having the same frequency and spatial phase difference on the transport surface of the main track 16 and the return surface of the return track 17. Is to generate bending in the transport surface of the main track 16 and the return surface of the return track 17 by expanding and contracting in the longitudinal direction of the plate elastic body 11, and the main track side area and the return track side area of the plate elastic body 11 Are provided along the long axis L direction, respectively. The piezoelectric element 41 arranged at a position along the main track side area and the piezoelectric element 41 arranged at a position along the return track side area are provided with a spatial phase difference from each other as shown in FIGS. 2 and 3. Has been done. In the present embodiment, the main track side area is set to the first vibration region Z1 for generating the 0 ° mode wave, and the return track side area is set to the second excitation region Z1 for generating the 90 ° mode wave. It is set in the vibration region Z2.

As shown in FIG. 3, the piezoelectric element 41 of the first vibration region Z1 is connected to the first amplifier 51, and the piezoelectric element 41 of the second vibration region Z2 is connected to the second amplifier 52. Each of the piezoelectric elements 41 is arranged at the antinode position of the vibration mode in the first vibration region Z1 and the second vibration region Z2 at 1/2 wavelength intervals. Since the piezoelectric elements 41 adjacent to each other in each vibration region (first vibration region Z1 and second vibration region Z2) have an amplitude peak and valley relationship, they are displaced in the opposite directions when the same drive is applied. (Represented by "+" and "-" in FIGS. 2 and 3). That is, in order to generate bending vibration in the vertical direction on the transport surface and vibrate efficiently, the piezoelectric element 41 is attached below (back side) of the transport surface at the antinode position of the vibration mode at 1/2 wavelength intervals. The polarities of the piezoelectric elements 41 adjacent to each other in the transport direction are alternately exchanged.

In the first vibration region Z1 and the second vibration region Z2, two vibration modes in which the phases of the waves are spatially shifted by 90 ° while having the same frequency, specifically, the 0 ° mode shown in FIG. 9 In order to generate a wave in the 90 ° mode and vibrate efficiently, for example, as shown in FIG. 3, the first vibration region Z1 is in the transport direction of the work in the return track 17 with respect to the second vibration region Z2. A spatial phase difference of (n + 1/4) λ (n = 0 or a positive integer) is set along the line, and the piezoelectric elements 41 having the same polarity are arranged in the first vibration region Z1 and the second vibration region Z1. Is installed so that it is substantially displaced by λ / 4 (installation conditions). As described above, in the present embodiment, the piezoelectric elements 41 are arranged with a 1/4 wavelength shift. In FIG. 9, at the same position of the 0 ° mode wave and the 90 ° mode wave, the node of the 0 ° mode wave and the antinode of the 90 ° mode wave coincide with each other, and there is a 90 ° spatial phase difference. Can be understood.

A standing wave simply vibrates on the spot when it resonates. Further, the piezoelectric element 41 may be integrated and may have a configuration in which the polarities of the electrodes on the surface are alternately exchanged, or may have polarities opposite to those shown in FIGS. 2 and 3. Further, the piezoelectric element 41 is provided in each of the first vibration region Z1 (main track side area) and the second vibration region Z2 (return track side area), or the piezoelectric element 41 is provided in one vibration region. The arrangement may be arranged so as to be offset by λ / 4. Further, the plate elastic body 11 may be attached to the back side and the front side of the portion where the transport surface (the transport surface of the main track 16 and the return surface of the return track 17) is formed. That is, two or more piezoelectric elements 41 may be provided anywhere in the transport unit 1 as long as the above-mentioned mounting conditions are satisfied.

Since the transport unit 1 does not have a symmetrical structure, there is a difference (f1 <f2) between the natural frequency f1 in the 0 ° mode and the natural frequency f2 in the 90 ° mode of the transport unit 1. As shown in FIG. 3, the linear feeder LF according to the present embodiment uses at least the mechanical phase difference caused by the difference between the natural frequency f1 and the natural frequency f2 as the temporal phase difference for generating the traveling wave. It is provided with a mechanical phase difference acquisition means for acquiring as a included element. Here, the mechanical phase difference is a phase difference caused by the difference in the natural frequencies of the two vibration modes. That is, the mechanical phase difference is a phase difference derived from the asymmetric shape of the transport unit 1, and when the vibration modes of two different natural frequencies are vibrated at one frequency, the two standing waves are formed. The difference in time phase that occurs. "Difference in natural frequency" means that the two vibration modes have the same deformation form and the same number of waves, which is the difference between the natural frequencies of the two different vibration modes, and the number of vibration modes. And, the number of standing waves for generating a traveling wave does not always match. The "same deformation form" described here means, for example, that the vibration directions and vibration methods of the two vibration modes are the same, and the "same wave number" is the vibration mode of the transport unit. It means the number of waves. That is, when the object is vibrated, there are two vibration modes having a spatial phase difference, and there is no case where the vibration modes are three. Therefore, for example, even in a configuration in which three or more standing waves having the same frequency, the same deformation form, and the same number of waves and having a spatial phase difference are generated on the transport surface, the vibration modes are mutually natural vibrations. There are two different numbers, the first vibration mode and the second vibration mode. Since the spatial phases are 90 ° out of alignment with each other, the first vibration mode can be defined as the 0 ° mode and the second vibration mode can be defined as the 90 ° mode among the two vibration modes.

Since the natural frequencies of 0 ° mode and 90 ° mode do not completely match, when driving at a certain frequency, a phase difference occurs between the two standing waves (0 ° mode and 90 ° mode), causing vibration. When the frequency is changed, the phase difference also changes, and at the same time, it deviates from the resonance peak, so that an amplitude difference also occurs. Therefore, changing the excitation frequency is equivalent to changing the phase difference and the amplitude ratio as a result. Therefore, in the present embodiment, as the mechanical phase difference acquisition means, not only the mechanical phase difference caused by the difference between the natural frequency f1 and the natural frequency f2, but also the mechanical phase difference caused by the excitation frequency of the drive signal. Is applied as an element included in the temporal phase difference for generating a traveling wave.

Further, in the present embodiment, the mechanical phase difference acquisition means acquires the mechanical phase difference due to the attenuation characteristic of the transport unit 1 as an element included in the temporal phase difference for generating the traveling wave. It is configured. This configuration focuses on the fact that the mechanical phase difference also changes if the damping characteristic of the transport unit 1 changes.

As shown in FIG. 3, the linear feeder LF according to the present embodiment includes a waveform selection means 6 for selecting a waveform. The waveform selection means 6 selects one waveform from a plurality of types of waveforms such as a sine wave, a square wave, and a triangular wave. Further, the linear feeder LF according to the present embodiment includes an electrical phase difference adjusting means 7 for adjusting the electrical phase difference of the waveform applied to each vibration mode, and the electrical phase difference adjusting means 7 is a mechanical phase difference. It is configured to adjust and give the temporal phase difference of the drive signal to the plurality of drive means 4 (first drive means 41, second drive means 42) with respect to the mechanical phase difference acquired by the acquisition means. doing. The "electrical phase difference" is the phase difference of the voltage waveform applied to each of the driving means 4 for the two vibration modes, and is a temporal phase difference command given from the outside. The linear feeder LF according to the present embodiment regards the phase difference including not only the electrical phase difference but also the mechanical phase difference as the temporal phase difference, so that the temporal phase difference matches 90 ° or approximately 90 °. This makes it possible to generate a traveling wave with the most efficient traveling wave ratio on at least the transport surface of the main track 16.

Further, the linear feeder LF according to the present embodiment has the amplitude of the excitation frequency adjusting means 8 for adjusting the excitation frequency and all the standing waves (standing wave in 0 ° mode, standing wave in 90 ° mode). (1st amplitude adjusting means 91, 2nd amplitude adjusting means 92) are provided. The first amplitude adjusting means 91 and the second amplitude adjusting means 92 adjust so that the amplitude of the standing wave in the 0 ° mode and the amplitude of the standing wave in the 90 ° mode are equal to each other.

In such a configuration, the linear feeder LF according to the present embodiment is phase-shifted by 90 ° with respect to the piezoelectric element 41 in the first vibration region Z1 and the piezoelectric element 41 in the second vibration region Z2. When an ultrasonic sinusoidal vibration is applied, two standing waves that are spatially and temporally displaced by 90 ° are superposed, the transport surface of the main track 16 itself is elastically deformed, and the deflection vibration becomes a traveling wave (circulation). method). Similarly, the return surface itself of the return track 17 resonates and elastically deforms, and the bending vibration becomes a traveling wave (circulation method). When a traveling wave is generated, the locus of one point on the transport surface of the main track 16 and the return surface of the return track 17 draws an elliptical vibration, and when this elliptical vibration reaches the apex of the transport surface or the apex of the return surface, it becomes a work. Contact and give frictional force to the work. The work is conveyed in the direction in which the frictional force acts. The transport direction of this work is opposite to the traveling direction of the traveling wave. Then, by adjusting the phase difference of the wave vibration (for example, sinusoidal vibration) applied to the piezoelectric element 41 in the two regions (first vibration region Z1 and second vibration region Z2), the traveling wave ratio (traveling wave) is adjusted. The work can be conveyed by adjusting the ratio = minimum amplitude / maximum amplitude) to generate a complete or almost perfect traveling wave.

Then, in the linear feeder LF according to the present embodiment, the cross-sectional shape of the transport portion 1 is set to the characteristic shape shown in FIGS. 5 and 6 in order to further improve the transport speed. In the present embodiment, the transport surface of the main truck 16 is formed in at least a part of the outer peripheral portion which is a region along the outer peripheral edge 1E of the transport unit 1, and the transport unit 1 is cut with a vertical cross section crossing the transport surface. Regarding the cross-sectional shape, the wall thickness of the outer peripheral region including the transport surface of the main track 16 in the vertical direction is formed to be larger than the wall thickness of the region inside the transport surface of the main track 16 in the horizontal direction. The transport unit 1 is applied. Specifically, the outer peripheral portion of the transport portion 1 including the transport surface of the main truck 16 is set to have a shape protruding downward with respect to the region inside the transport portion 1 (see FIG. 5).

In the present embodiment, the shape of the transport portion 1 is set so that the wall thickness gradually decreases from the outer peripheral edge 1E of the transport portion 1 toward the region reaching the thin wall portion 12. Therefore, in the transport portion 1 of the present embodiment, the cross-sectional shape is substantially triangular in the region from the outer peripheral edge 1E of the transport portion 1 to the thin-walled portion 12. Further, in the present embodiment, a large number of slits 18 orthogonal to the transport surface of the main track 16 are formed on the outer peripheral portion of the transport portion 1. As shown in FIGS. 5, 6 and 8, each slit 18 has a depth deeper than the groove shape of the transport surface of the main track 16 and does not reach the bottom surface 1B of the transport portion 1, and is upward and the transport portion. It is open to the outer peripheral edge 1E of 1. In the present embodiment, each slit 18 is formed over a region reaching the thin portion 12 from the outer peripheral edge 1E of the transport portion 1. Therefore, in the present embodiment, both the transport surface of the main track 16 and the return surface of the return track 17 are divided at a predetermined pitch by the slits 18 along the transport direction of the work. By forming a large number of such slits 18 on at least the outer peripheral portion of the transport portion 1, the slits 18 are formed on the outer peripheral portion, so that the traveling wave is compared with the configuration in which the slits 18 are not formed on the outer peripheral portion. The "neutral axis", which is the position where no load is applied and neither tension nor compression is generated when the above-mentioned occurs, is lowered (approaching the bottom surface 1B of the transport portion 1). As a result, the distance (e value) from the transport surface to the neutral axis when a traveling wave is generated on the transport surface of the main truck 16 provided on the outer peripheral portion becomes large, and the transport speed of the work is improved.

Here, as shown in FIG. 10A, for example, focusing on the cross-sectional shape of the transport portion 1 in which the slit 18 is formed, the region of the transport portion 1 in which the slit 18 is formed becomes substantially triangular. The region from the long side 1H to the bottom surface 1B of the transport portion 1 is a thick portion 1N (a portion shaded in parallel in the figure) in which the slit 18 is not formed. The thick portion 1N is connected over the entire length of the transport portion 1 in the major axis direction. Therefore, in the substantially triangular region where the slit 18 is formed in the transport portion 1, the wall thickness is considered in considering the local behavior of the apex 1T having the long side 1H as the opposite side and the region near the apex 1T (projection portion Q2). Part 1N can be considered to be close to the restrained state. According to such a shape, local vibration is less likely to occur in the protrusion Q2 in the substantially triangular region in which the slit 18 is formed, as compared with the shape in which the wall thickness of the transport portion 1 is substantially constant. Become.

This can be understood from the schematic diagram shown in FIG. 10 as follows. In FIG. 10A, the mass and rigidity gradually increase from the restraint region (Q1) including the thick portion 1N to the restraint region (Q1) from the portion (Q2) located farthest. That is, the structure is such that the mass is the smallest in the portion (Q2) where the amplitude is the largest when vibration occurs, and the rigidity is the largest in the portion (Q1) where the strain is the largest. On the other hand, in FIG. 10B, the portion located farthest from the restraint region (Q1') including the thick portion 1N'(the side 1T'which is the opposite side of the long side 1H' and the region in the vicinity thereof. The mass and rigidity from the part indicated by the symbol (Q2') to the restraint region (Q1') are almost constant. Therefore, the natural frequency is higher in the shape of the transport unit 1 shown in FIG. 10 (a) than in the shape of the transport unit 1'shown in FIG. 10 (b).

Since the transport unit 1 in the present embodiment shown in FIG. 5 and the like has the configuration and shape described above, the apex 1T located farthest from the restraint region (Q1) and the portion near the apex 1T (Q2) are located. The natural frequency of the vibration mode that vibrates greatly locally becomes larger than the shape in which the wall thickness of the transport portion 1 shown in FIG. 10B is substantially constant, and local vibration occurs. It has a difficult structure.

Further, the larger the distance (e value) from the transport surface to the neutral axis when a traveling wave is generated on the transport surface of the main track 1, the larger the amplitude, and the faster the work can be transported. Since the transport unit 1 in the present embodiment has the above-mentioned shape, the e value of the outer peripheral portion of the transport unit 1 which is a region along the outer peripheral edge 1E is horizontal with respect to the transport surface of the main truck 1. It becomes a large value as compared with the e value of the region inside in the direction. As a result, the transport speed of the work along the transport surface of the main truck 16 formed on the outer peripheral portion of the transport unit 1 can be increased.

Furthermore, in the present embodiment, a large number of slits 18 orthogonal to the transport surface of the main track 16 are formed on the outer peripheral portion of the transport portion 1. As shown in FIGS. 5, 6 and 8, each slit 18 has a depth deeper than the groove shape of the transport surface of the main track 16 and does not reach the bottom surface 1B of the transport portion 1, and is upward and the transport portion. It is open to the outer peripheral edge 1E of 1. In the present embodiment, each slit 18 is formed over a region reaching the thin portion 12 from the outer peripheral edge 1E of the transport portion 1. Therefore, in the present embodiment, both the transport surface of the main track 16 and the return surface of the return track 17 are divided at a predetermined pitch by the slits 18 along the transport direction of the work. By forming a large number of such slits 18 on at least the outer peripheral portion of the transport portion 1, the transport speed of the work on the transport surface of the main track 16 provided on the outer peripheral portion can be further increased, and the slits on the outer peripheral portion can be further increased. By forming the 18, the neutral axis is lowered (closer to the bottom surface 1B of the transport portion 1) as compared with the configuration in which the slit 18 is not formed on the outer peripheral portion. As a result, the distance (e value) from the transport surface to the neutral axis when a traveling wave is generated on the transport surface of the main truck 16 provided on the outer peripheral portion becomes large, and the transport speed of the work is improved.

Here, FIG. 11 shows a schematic view in which the elastic deformations of the transport portions having slits formed along the work transport direction are arranged in chronological order, and the transport portions having slits not formed along the work transport direction are shown in FIG. FIG. 12 shows a schematic diagram in which elastic deformations are arranged in chronological order. In FIGS. 11 and 12, the “transport surface”, “neutral axis”, and “bottom surface” in the state before elastic deformation are shown by straight lines, and “a certain point (black circle)” of the transfer surface when the transport portion is elastically deformed is shown. The locus of "" is shown in an elliptical shape, and it is schematically shown that elliptical vibration occurs when elastically deformed. The height dimensions (dimensions from the bottom surface to the transport surface) of the transport portion before elastic deformation shown in FIGS. 11 and 12 are the same, and the following points can be grasped from these figures. That is, the distance (e value) from the transport surface of the transport portion having the slit shown in FIG. 11 to the neutral shaft is the distance (e) from the transport surface of the transport portion not forming the slit shown in FIG. 12 to the neutral shaft. The horizontal amplitude of the transport section with slits is larger than the horizontal amplitude of the transport section without slits, and the vertical amplitude of the transport section with slits is not slit. It is smaller than the vertical amplitude of the transport section. As a result, the transport portion in which the slit is formed has a higher transport speed of the work as compared with the transport portion in which the slit is not formed, and the unintended jump of the work on the transport surface can be effectively reduced. ..

As described above, in the linear feeder LF according to the present embodiment, the local vibration of the apex 1T in the cross-sectional shape of the transport portion 1 and the region near the apex 1T (the region indicated by the reference numeral (Q2) in FIG. 10A) is suppressed. At the same time, the slit 18 can be deepened, the distance (e value) from the transport surface of the main track 16 to the neutral axis can be kept at a large value, and the traveling wave generated along the transport track 13 allows the work to be constructed. A frictional force is generated between the work and the transport surface of the main track 16 and between the work and the return surface of the return track 17, so that the work can be transported smoothly and at high speed, and the work supply processing capacity and the work can be performed. Recovery processing capacity is improved.

By providing a large number of slits 16 in the transport portion 1 in order to improve the transport speed, a large number of comb-shaped protrusions are formed in the transport portion 1. Then, when the cutting depth (slit depth) of each slit 16 is deepened, the natural frequency of the natural vibration mode that accompanies bending of the protrusion becomes low. This can be understood as follows.

When one of the protrusions formed by providing the slit is regarded as a cantilever, increasing the slit depth corresponds to increasing the length of the cantilever. When the length of the cantilever is increased, the natural frequency of the bending vibration mode of the cantilever becomes lower. This is because the natural frequency of the protrusion increases or decreases in inverse proportion to the mass of the protrusion, and as described above, the length of the protrusion becomes longer (the length of the cantilever is increased). As a result, the mass of the protrusion is increased, so that the value of the natural frequency of the protrusion is lower than that when the slit depth is shallow. When the slit is shallow and the natural frequency of the natural vibration mode with bending of the protrusion is (much) higher than the drive frequency, the influence of such vibration does not occur. However, when the natural frequency becomes low and approaches the drive frequency, bending vibration of the protruding portion is likely to occur even when the traveling portion 1 is bent to generate a traveling wave, which hinders smooth transport. In the work transfer device according to the present embodiment, it is desirable that flexion vibration is generated in the entire transfer section 1 so as to form a wave along the outer circumference. It is not desirable that bending vibration of the part occurs. That is, when the traveling wave traveling wave used for transport is generated by utilizing the bending vibration of the entire transporting portion, the protrusion itself does not bend, and the protruding portion is rigidly swung along the bending of the thick portion. It is desirable to have a vibrating state like this.

Further, according to the linear feeder according to the present embodiment, the conventional configuration shown in FIG. 13, that is, the cross-sectional shape of the transport portion A1 has a substantially uniform wall thickness in a predetermined region from the outer peripheral edge A1E toward the inside. In comparison, the height position of the portion that supports and fixes the transport portion 1 from below (in the present embodiment, the portion of the support base 2 that is in contact with the downward surface of the thin portion 12 of the transport portion 1). Can be brought closer to the height position of the transport surface of the main truck 16, and the inward vibration (vibration in the direction perpendicular to the transport direction in the horizontal plane) in the transport unit 1 is smaller than that of the configuration shown in FIG. This is reduced, and it is possible to prevent / suppress an event in which the work transported on the transport surface of the main truck 16 jumps off the transport surface. 13 (a) and 13 (b) are diagrams showing the linear feeder ALF to be compared with the present embodiment corresponding to FIGS. 8 and 5, respectively, with the transfer unit 1 in the present embodiment. An "A" is added to the beginning of each code that indicates the corresponding part of the relationship.

Further, since the linear feeder LF according to the present embodiment transports the work by the ultrasonic deflection traveling wave in the vertical direction, the horizontal amplitude of the tip of the transport unit 1 is close to zero, and the tip of the transport unit 1 is used as the next process device. Since it can be installed close to each other, it is possible to prevent and suppress the fall of small workpieces, and the piezoelectric element 41 is configured to generate a traveling wave by ultrasonic vibration, the driving sound is heard by the human ear. It is inaudible, can be muted, and can achieve high speed while preventing loud noise.

Since the linear feeder LF according to the present embodiment bends and vibrates only the transport truck 13 set on the outside of the thin-walled portion 12, as described above, the deflection vibration of the transport truck 13 even if the central portion of the transport portion 1 is fixed. A traveling wave can be obtained without affecting the mode. By inverting the phase difference of the waves given to the piezoelectric element 41 in the first excitation region Z1 and the piezoelectric element 41 in the second excitation region Z2 (time phase is inverted (−90 °)). , The work can be conveyed in the opposite direction, and when the work is clogged, the work can be temporarily fed back and the clogging can be cleared.

Further, a configuration similar to the above-described configuration of the linear feeder LF can be applied to the bowl feeder BF shown in FIG. As shown in FIGS. 1 and 14, the bowl feeder BF has a plurality of standing portions having a spatial phase difference at the same frequency as the bowl-shaped transport portion 1 (B) having an asymmetrical shape with respect to an arbitrary axis. A plurality of driving means 4 (B) for generating waves on the transport surface of the spiral track 16 (B) are provided, and the plurality of driving means 4 (B) have a configuration similar to or similar to that of the linear feeder LF described above. By giving a drive signal having a temporal phase difference including a mechanical phase difference in addition to the electrical phase difference, the spiral track 16 (B), which is a spiral transfer track in the bowl-shaped transfer section 1 (B), is given. ), A traveling wave is generated on the transport surface to transport the work to a predetermined transport destination (supply destination, upstream end of the main track 16 of the linear feeder LF in this embodiment). FIG. 14 is a diagram schematically showing a side cross section of the bowl feeder BF, and parallel diagonal lines (hatching) indicating the cross section are omitted.

The bowl-shaped transport portion 1 (B) is formed by a bowl elastic body 11 (B) which is an elastic member that generates a traveling wave. The end portion (downstream end portion) of the spiral track 16 (B) having a transport surface that rises from the bottom side and draws a spiral shape is connected to the start end portion (upstream end portion) of the main track 16 in the linear feeder LF. There is. In the present embodiment, the central portion of the bowl elastic body 11 (B) is fixed to the support base 2 (B) by appropriate parts (fastener (bolt) in FIG. 1 and holding member 14 (B) in FIG. 14). ing.

Then, as shown in FIG. 14, the transport unit 1 (B) sets the wall thickness of the spiral track 16 (B) in the cross-sectional shape of the region on the outer peripheral side including the transport surface of the spiral track 13 (B) in the vertical direction. It is set to be larger than the wall thickness in the cross-sectional shape of the region inside the region in the horizontal direction with respect to the transport surface. Further, the transport portion 1 (B) is formed so that the outer peripheral portion including the transport surface of the spiral track 16 (B) has a shape protruding upward from the region inside the spiral track 16 (B). The transport portion 1 (B) is formed so that the outer peripheral portion including the transport surface of the spiral track 13 (B) has a shape protruding upward from the region inside the spiral track 13 (B). Further, a large number of slits 18 (B) orthogonal to the transport surface of the spiral track 13 (B) are formed on the outer peripheral portion of the transport portion 1 (B), and the slits 18 (B) are formed on the spiral track 13 (B). The depth is deeper than the groove shape of the transport surface of the above and does not reach the bottom surface of the transport portion 1 (B), and is open to the upper side and the outer peripheral edge 1E (B) of the transport portion 1 (B).

The bowl feeder BF provided with such a transport portion 1 (B) has the same or substantially the same effect as the above-mentioned linear feeder LB.

The present invention is not limited to the above-described embodiments. For example, for a cross-sectional shape cut with a vertical cross section orthogonal to the transport surface, the wall thickness of the region on the outer peripheral side including the transport surface in the vertical direction is larger than the wall thickness of the region inside the transport surface in the horizontal direction. As shown in FIG. 15, in the present invention, the region of the transport portion 1 on the upper surface side of the outer peripheral portion including the transport surface is made of a low elastic modulus material, and the other regions are low. A material composed of a high elastic modulus material having a higher elastic modulus than the elastic modulus material can be adopted. Specifically, the region 1L of the transport unit 1 including at least the transport surface of the main track 16 is formed of a material having a low elastic modulus such as resin, and the other region 1H (the region below the transport unit 1) is made of metal or the like. A material formed of a material having a high elastic modulus can be adopted. With such a configuration, the neutral axis can be lowered to the bottom surface 1B side of the transport unit 1 as compared with the embodiment in which the entire transport unit 1 is formed of the same material, and the traveling wave is transmitted to the transport surface of the main truck 16. The distance (e value) from the transport surface of the main truck 16 to the neutral axis when it is generated becomes large, and the transport speed is improved. Further, although local vibration is likely to occur in at least the region including the transport surface of the main truck 16 in the transport portion 1, the umbrella shape shown in FIG. 15 (a shape having a portion having a triangular cross-sectional shape on both sides). By setting to, it is possible to suppress local vibration in the region 1L formed of a material having a low elastic modulus and generate an appropriate traveling wave. In this way, by forming the upper region of the transport portion 1 with a material having a low elastic modulus and a low coefficient of restitution, it is possible to suppress jumping of the work during the transport process. Note that FIG. 15 is a diagram corresponding to FIG.

In the present invention, in a configuration in which a large number of slits are provided in the transport portion and set as a comb-shaped transport surface, a film (not shown) may be attached to the comb-shaped transport surface to prevent the work from falling into the slits. ..

Further, in the work transfer device of the present invention, a transfer unit having no slit can be applied. If the transport portion is not provided with slits, the problem of the work stumbling at the slits does not occur. Even if the transport portion is not provided with a slit, the cross-sectional shape of the predetermined region of the transport portion including the transport surface is substantially triangular, so that the above-mentioned effects described in detail with reference to FIG. 10 can be obtained.

The transport portion in the present invention is preferably formed so that the outer peripheral portion including the transport surface has a shape protruding upward or downward from the region inside the transport portion of the linear feeder. As a result, it is possible to apply a shape in which the outer peripheral portion including the transport surface is formed so as to have a shape protruding upward from the region inside the transport surface.

Further, the transport portion in the present invention may be formed so that the wall thickness is gradually reduced from the outer peripheral portion including the transport surface to the region inside the transport portion.

In the above embodiment, the traveling wave is generated by the traveling method, but the traveling wave may be generated by a method other than the circulating method (such as a double-ended vibration method in which both ends of the transport surface are vibrated by changing the phase difference). ..

In the present invention, a magnetostrictive element can be applied as the driving means instead of the piezoelectric element.

Examples of the work include minute parts such as electronic parts, but may be articles other than electronic parts.

In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

1, 1 (B) ... Conveying parts 18, 18 (B) ... Slits 1B, 1B (B) ... Bottom surface 1E, 1E (B) of the transporting part ... Outer peripheral edges of the transporting part 4, 4 (B) ... Driving means LF , BL ... Work transfer device (linear feeder, bowl feeder)

Claims (6)

The traveling portion is provided with a transport portion in which a transport surface is formed in at least a part of an outer peripheral portion which is a region along the outer peripheral edge, and a driving means for generating a traveling wave in the transport portion, and the transport portion is elastically vibrated to generate the traveling wave. A work transfer device that conveys a work on the transfer surface by waves.
The transport portion is formed by an elastic body which is an elastic member that generates the traveling wave.
The transport surface is formed by the single elastic body.
The transport portion has a cross-sectional shape cut with a vertical cross section orthogonal to the transport surface that crosses the transport surface, and the wall thickness of the outer peripheral side region including the transport surface in the vertical direction is horizontal with respect to the transport surface. what der those formed to be larger than the thickness of the inner region in the direction, and the rigidity of the outer peripheral side region in the vertical direction, the medium in the transport unit from the region where the conveying surface is formed workpiece transfer apparatus according to claim der Rukoto which rigidity was set to gradually increase toward the standing axis. The work transport according to claim 1, wherein the transport portion is formed so that the outer peripheral portion including the transport surface has a shape protruding upward or downward from a region inside the transport surface. Device. The work according to claim 1 or 2, wherein the transport portion is formed so that the wall thickness gradually or gradually decreases from the outer peripheral portion including the transport surface to a region inside the transport portion. Conveyor device. Of the transport portion, a region on the upper surface side of the outer peripheral portion including the transport surface is composed of a low elastic modulus material, and the other region is composed of a king having a higher elastic modulus than the low elastic modulus material. The work transfer device according to any one of claims 1 to 3. The transport surface is formed so as to form a groove that opens upward on the upper surface side of the transport portion.
A large number of slits orthogonal to the transport surface are formed on the outer peripheral portion of the transport portion.
The slit is deeper than the groove shape of the transport surface so as not to reach the bottom surface of the transport portion, and is open to the upper side and the outer peripheral edge of the transport portion according to any one of claims 1 to 4. The work transfer device described. In the transport portion, a return surface composed of two straight portions parallel to the transport surface and a U-turn portion connecting these two straight portions is formed in a region closer to the inside than the transport surface. The work transfer device according to any one of claims 1 to 5.

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