JP2013040025A - Parts conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parts conveyor whose structure is made as simple as possible, whose manufacturing cost is low, and which has a function capable of more reliably eliminating parts-jamming, even in the case of small-sized parts.SOLUTION: The parts conveyor includes: a linear conveying table for conveying the parts with application of conveyance vibration; and excitation devices each including a piezoelectric element for applying release vibration for releasing parts-jamming on the conveying table to the conveying table. Regarding the conveying table, the piezoelectric element is provided to include a position where the amplitude of a vibration wave becomes the maximum when the conveying table vibrates with natural frequency.

Description

  The present invention relates to a component conveying apparatus having a function of releasing a clogged component when the component being conveyed is jammed.

  2. Description of the Related Art As a device that transports components by vibration, a component transport device (part feeder) that transports components in a predetermined direction along a linear or curved transport track is widely known.

  In such a component conveying apparatus, components may be clogged on the conveying table due to adhesion due to static electricity or overlapping of components, and when such clogging occurs, the components cannot be conveyed downstream.

  In order to release the clogging of parts, for example, there are a method of stopping the conveying device and using manual tweezers to release the clogging of parts, a method of injecting air with an air blowing means, and a method of releasing clogging of parts. However, in any case, the clogging of the parts could not be reliably removed, and in the latter case, there was a problem that the processing of the apparatus was troublesome.

  On the other hand, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2-305707) proposes a component clogging removal method in a vibrating part transporter that can reliably remove clogging of components by reducing the manufacturing cost. ing.

  Specifically, “vibrating component conveyance in which components are conveyed in a predetermined direction along a conveyance track by vibration, component clogging detection means is provided, and clogging of the components is removed by detection output of the means. In the part clogging removal method in the machine, when the part clogging detection means detects clogging of parts, the detection output is used to vibrate the parts in the direction opposite to the predetermined direction. A method for removing clogging of components in a vibrating component conveyor as a feature has been proposed.

JP-A-2-305707

  However, even with the component clogging removal method proposed in Patent Document 1, when the components to be transported are small, these components adhere firmly to the surface of the transport table due to static electricity or the like. There is a problem that it cannot be canceled reliably.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a component transport device with a component clogging release function that has a function capable of removing a component clog more reliably even with a small component, with a structure as simple as possible and having a low manufacturing cost. There is to do.

In order to solve the above problems, the present invention provides:
A linear transfer table for transferring parts by applying transfer vibrations;
An excitation device including a piezoelectric element that applies a release vibration to the transfer table to release clogging of components on the transfer table;
The piezoelectric element is provided so as to include a position where the amplitude of the vibration wave is maximum when the transfer table vibrates at a natural frequency in the transfer table;
A component conveying apparatus characterized by

  Here, the vibration device including the “piezoelectric element” according to the present invention separates the adhesion due to static electricity and the component on the conveyance table separately from the conveyance vibration applied to the linear conveyance table for conveying the component. It is a device for applying a release vibration for releasing a component clogging caused by an overlap or the like.

  The release vibration applied by the vibration device may be applied by, for example, the piezoelectric effect or electromagnetic force. In a linear transport table, the length direction, the width direction, or the height direction of the transport table may be used. What is necessary is just to apply the release vibration which vibrates at least in any direction.

  This vibration device may be provided on any part of the conveyance table as long as it has the above-described effects and does not hinder the conveyance of the parts. For example, it may be bonded to or embedded in the upper surface (inside or outside of the groove), side surface, or lower surface of the transfer table, or may be embedded in the transfer table.

  According to the component conveying apparatus of the present invention having such a configuration, even if the component being conveyed by the conveying vibration on the linear conveying table is clogged at any position, the release vibration is applied. Parts clogging is effectively released. In particular, since a plurality of vibration devices are provided at a position corresponding to at least the antinode of the vibration wave wavelength of the carrier vibration in the carrier table, the release vibration increases due to resonance, and the component clogging is more reliably released. be able to.

  Moreover, in the said component conveying apparatus of this invention, it is preferable that the length of the said piezoelectric element in the length direction of the said conveyance stand is 40 to 70% of 1/2 wavelength of the vibration wave of the said natural vibration. .

  Such a configuration is preferable because the piezoelectric element can be displaced as much as possible to generate a large release vibration, and the effects of the present invention can be obtained more reliably.

  According to the present invention, it is possible to provide a component conveying device with a component clogging release function that has a function capable of removing a component clog more reliably even with a small component, with a structure as simple as possible and having a low manufacturing cost. Can do.

It is a schematic side view of one Embodiment of the components conveying apparatus of this invention. It is the figure which looked at the part of the conveyance stand 12 of the component conveying apparatus 10 shown by FIG. 1 from the arrow A direction. FIG. 2 is a schematic diagram for explaining the concept of the natural frequency with respect to the vibration of the transport table 12 in the component transport apparatus 10 shown in FIG. 1. It is a schematic diagram of the conveyance stand 12 in FIG. FIG. 5 is a schematic diagram conceptually showing the positions of antinodes of vibration waves in the case where n = 1 to 3 in the transport table 12 shown in FIG. 4. And distance Y positions of the antinodes P ₆ of the center C in the conveying direction of the piezoelectric element constituting the vibrator 14 is a diagram for explaining the length A of the piezoelectric element, the relationship. In one embodiment of the component conveying apparatus of the present invention, the relationship between the ratio of the length L of the piezoelectric element to the half wavelength A of the vibration wave having the natural frequency f of the conveying table 12 and the displacement amount of the piezoelectric element. It is a schematic diagram for demonstrating. In one embodiment of the component conveying apparatus of the present invention, the relationship between the ratio of the length L of the piezoelectric element to the half wavelength A of the vibration wave having the natural frequency f of the conveying table 12 and the displacement amount of the piezoelectric element. It is a graph which shows. It is a schematic diagram of the conveyance stand 12 in the deformation | transformation aspect of the components conveying apparatus shown in FIG. FIG. 10 is a schematic diagram conceptually showing the positions of antinodes of vibration waves when n = 1 to 3 in the transport table 12 shown in FIG. 9.

  Hereinafter, an embodiment of a component conveying apparatus of the present invention will be described with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description may be omitted. In addition, the shape and size of each member in each drawing may not necessarily represent the shape and size for achieving the effects of the present invention with high accuracy.

  FIG. 1 is a schematic side view of an embodiment of a component conveying device 10 with a component clogging release function according to the present invention, and FIG. 2 shows a portion of a conveying table 12 of the component conveying device 10 shown in FIG. It is the figure seen from the direction. FIG. 3 is a schematic diagram for explaining the concept of the natural frequency with respect to the vibration of the conveying table 12 in the component conveying apparatus 10 shown in FIG.

  As shown in these drawings, the component conveying apparatus 10 of the present embodiment includes a linear feeder drive unit 8, a linear conveying table 12 for conveying components in the conveying direction indicated by the arrow X by application of conveying vibration, and The first vibration device 14a and the second vibration device 14b for applying the release vibration for releasing the component clogging on the transport table 12 to the transport table 12, the oscillator 16, and the amplifier 18. Have. The linear feeder is composed of a drive unit 8 and a transport table 12.

The conveyance stand 12 is substantially linear, and has a conveyance groove 12a extending in the length direction on the upper side as shown in FIG. Although not shown, conveyance vibration is applied to the conveyance table 12 from the drive unit 8 of the linear feeder, and the component is conveyed in the conveyance direction indicated by the arrow X by the conveyance vibration. The frequency f _{1 of the} carrier vibration may be 100 to 500 Hz, for example.

  The first vibration device 14a and the second vibration device 14b for applying the release vibration for releasing the component clogging on the conveyance table 12 to the conveyance table 12 are composed of piezoelectric elements. The piezoelectric elements are respectively provided on the lower surface of the transport table 12 so that a release vibration that vibrates in the length direction of the transport table 12 is applied to the transport table 12.

  The oscillator 16 outputs to the amplifier 18 a voltage whose waveform is a sine wave (hereinafter also referred to as “sine wave voltage”). When the sine wave voltage is input, the amplifier 18 amplifies the sine wave voltage and outputs the amplified sine wave voltage to the first vibration device 14a or the second vibration device 14b.

  When a voltage is input to the first vibration device 14a and the second vibration device 14b, a force (bending moment) for bending the conveyance table 12 up and down according to the input voltage is applied to the conveyance table 12. Give continuously. In the case of this embodiment, since the input voltage is a sine wave, the first vibration device 14a or the second vibration device 14b is a force (bending moment) for continuously bending the conveyance platform 12 up and down. And bending vibration is applied to the conveyance table 12.

Here, in this embodiment, the frequency f _{2 of the} release vibration is set to be higher than the frequency f _{1 of the} carrier vibration, and from the viewpoint of low noise that cannot be heard by human ears, the frequency is in the ultrasonic region of 20 kHz or higher. Preferably there is. Further, from the viewpoint that if the frequency f ₂ of the release vibration and the frequency f _{1 of the} carrier vibration are sufficiently separated from each other, the waveform of the vibration wave due to the carrier vibration is not disturbed and there is no possibility of adversely affecting the conveyance. preferred frequency f ₂ of that set to at least 10 times the frequency f ₁ of the conveying vibration.

Here, assuming that the displacement in the bending vibration direction of the carriage 12 is x and the acceleration of the release vibration is a, the acceleration a is
Formula (1): a = x (2πf ₂ ) ² (1)
From this equation (1), the displacement x is
Formula (2): x = a / {(2πf ₂ ) ² } (2)
It is represented by The release of the component clogged needs to displacement x is large to some extent, but since the acceleration from the equation (2) the frequency f ₂ is higher, the more an displacement x becomes smaller at a constant, the release vibration frequency f ₂ The upper limit is preferably about 100 kHz.

  In addition, the first vibration device 14a and the second vibration device 14b in the present embodiment utilize piezoelectric elements. The piezoelectric element is an element such as crystal, Rochelle salt, or barium titanate crystal. When a force is applied to these piezoelectric elements, an electric polarization is generated in proportion to the stress and a voltage is generated (piezoelectric effect). When a voltage is applied to these crystals, a distortion is generated and the piezoelectric element is deformed (reverse piezoelectric effect).

  The first vibration device 14a and the second vibration device 14b are configured to convert electric power into kinetic energy using such a property of the piezoelectric element.

Furthermore, in the present embodiment, the first vibration device 14 a and the second vibration device 14 b are vibration waves W when the conveyance table 12 vibrates at the natural frequency f in the length direction of the conveyance table 12. (A ≠ b) are provided at the positions P _a and P _b that become the antinodes of the.

Here, referring to a schematic diagram (FIG. 3) for explaining the concept of the natural frequency with respect to the vibration of the carriage 12, the antinode of the vibration wave W when vibrating at the natural frequency is P _n (n is the order). There is a node of the vibration wave W in the middle of the adjacent belly, for example, at the position indicated by Q.

Further, the natural frequency f with respect to the vibration of the carriage 12 is expressed by the following equation (3):
f = π (2n + 1) ² / 8l ² × (EI / ρA) ^1/2 (3)
(Where, f is the length, E is the Young's modulus, ρ is the density, n is the order, A is the cross-sectional area, and I is the cross-sectional second moment).

The order n in the formula (3) is not particularly limited as long as the effect of the present invention is obtained, but may be, for example, 1 to 10, and in the present invention, the position of the belly corresponding to n = 1 to 10 P ₁ in at least two positions of the to P ₁₀ may be provided vibrating device, but in this embodiment the two positions _{P a} and _{P b (a ≠ b, 1} ≦ a ≦ 10,1 ≦ b ≦ 10), the first vibration device 14a and the second vibration device 14b are provided.

The two positions are separated, for example, antinode positions P ₅ and P ₈ corresponding to n = 5 and 8, or antinode positions P ₂ and P ₇ corresponding to n = 2 and 7, etc. Position, and for example antinode positions P ₆ and P ₇ corresponding to n = 6 and 7, antinode positions P ₈ and P ₉ corresponding to n = 8 and ₉ , or n = 9 and as such the position P ₉ and P ₁₀ corresponding belly 10 may be a position adjacent.

In the present embodiment, as shown in FIG. 1, the first vibration device 14 a and the second vibration device are formed on the lower surface of the carriage 12 at the positions of the antinodes P ₆ and P ₇ of n = 6 and 7, respectively. Device 14b is affixed with an adhesive.

In the component conveying apparatus of the present embodiment shown in FIG. 1, the positions of the two Q ₂ and Q ₃ are fixed ends because the conveying table 12 is fixed with fixing bolts, and Q ₁ and Q at both ends are fixed. _Although the position of ₄ is a free end, when the vibration frequency of the carriage 12 becomes sufficiently large (for example, about 10 times) with respect to the natural frequency of the fixing bolt, as shown in FIG. It can be approximated that there is no fixed end and there are free ends at the positions of Q ₁ and Q _{4 on} both ends.

  And in such a conveyance stand 12 shown in FIG. 4, the position of the antinode is determined by the order n. FIG. 5 shows a schematic diagram showing the position of the antinode of the transport table 12 as representative of the order n = 1-3. In FIG. 5, the antinode is a position indicated by a black circle.

Then, in the present embodiment, the arrangement of the first vibrator 14a and the second vibrator 14b is a center in the conveying direction of the piezoelectric elements constituting these respectively, the position of the antinode P ₆ and P ₇ It is preferable that the distance is set so as to be 1/2 or less of the length of the piezoelectric element.

This point will be described with reference to the drawings as a representative example of the first vibration device 14a. As shown in FIG. 6, the position of the center C in the transport direction of the piezoelectric elements constituting the first vibration device 14a. And the position Y of the antinode P ₆ is equal to or less than ½ of the length A of the piezoelectric element, that is, relational expression (4):
Y ≦ 1 / 2A (4)
It is preferable to satisfy. If it is this range, the effect that the conveyance stand 12 can be displaced (deformed) efficiently will be acquired.

Next, in the present embodiment, the vibrations of the first vibration device 14a and the second vibration device 14b of the piezoelectric elements constituting the first vibration device 14a and the second vibration device 14b are applied. the length L in the direction is from 40 to 70% of the half wavelength _{W a} of the vibration wave of the natural frequency f, and preferably from 50% to 60%.

7, for half-wave W _A vibration wave natural frequency f of the conveying table 12, and the ratio of the length L of the piezoelectric element, schematic view for explaining the displacement of the relationship between the piezoelectric element , and the 8, for half-wave W _a vibration wave natural frequency f of the conveying table 12, and the ratio of the length L of the piezoelectric element, and the displacement of the piezoelectric element, the relationship (simulation results ).

8, the horizontal axis, for half-wave W _A vibration wave natural frequency f of the carrying table 12, the ratio of the length L of the piezoelectric element (the ratio of the length of the piezoelectric element) (percent) The amount of displacement of the piezoelectric element is plotted on the vertical axis.

  As can be seen from the graph of FIG. 8, if the ratio of the length of the piezoelectric element is 40 to 70%, a sufficient amount of displacement of the piezoelectric element can be ensured, and a sufficient release vibration is applied to the carrier 12. can do. From the viewpoint that the release vibration can be more reliably applied to the carriage 12, the ratio of the length of the piezoelectric element is preferably 50 to 60%.

  Here, although not shown, the component conveying apparatus 10 of the present embodiment is provided with a frequency fluctuation device that changes the frequency of the release vibration. This frequency fluctuation device may be provided in the oscillator 16 or the amplifier 18 itself, but as a separate device, between the oscillator 16 and the amplifier 18 or between the amplifier 18 and the first vibration device 14a and the second vibration device. May be connected to the other vibration device 14b.

  In this way, if the frequency fluctuation device is provided, the state of the release vibration can be changed variously by changing the frequency. Therefore, when the clogging of parts cannot be released by the release vibration of a certain wavelength, For example, the clogging of the component can be released by changing the position of the antinode of the vibration wave and the position of the node.

  As a method of changing the frequency at this time, various conventionally known modes can be considered. For example, the frequency may be changed continuously or discontinuously. For example, several frequencies (modes) may be changed. A plurality of settings may be set and changed by switching between these modes. Note that the displacement of the carriage required to clear the part jam varies depending on the degree of the part jam, for example, the degree of adhesion (static electricity, intermolecular force, etc.) of the part to the carriage 12, the degree of catching, etc. It depends on the shape and frequency.

  Moreover, although not shown in figure, the component conveyance apparatus 10 of this embodiment is equipped with the detection apparatus which detects component clogging. As such a detection device, for example, an infrared sensor or the like can be used.

  Next, operation | movement of the components conveying apparatus 10 of this embodiment which has the above structure is demonstrated. First, in the driving unit 8 of the linear feeder, a conveyance vibration is applied to the conveyance table 12 to convey the component in the conveyance direction indicated by the arrow X.

  At this time, when an infrared sensor (not shown) detects that a component clogging has occurred in the groove 12a of the carriage 12, the oscillator 16 outputs a sine wave voltage to the amplifier 18, and the amplifier 18 Is amplified to obtain an amplified sine wave voltage, which is output to the first vibration device 14a or the second vibration device 14b.

Then, applying the first vibrator 14a or the second vibrator 14b, when amplified the sine wave voltage is input, the release vibrations at the location of the natural vibration wave antinode P ₆ and P ₇ in the conveying table 12 To do. Since these first vibrator 14a or the second vibrator 14b is placed at a position of antinode P ₆ and P ₇ of the natural vibration wave, releasing vibration is increased by the resonance, more reliable parts clogging Can be released.

  As mentioned above, although the structure and the operation | movement method were demonstrated about typical embodiment of the components conveying apparatus of this invention, referring drawings, this invention is not limited only to these, The technical idea of this invention Various design changes are possible within the range.

<Deformation mode>
In the modified embodiment of the above embodiment, it can be considered that the transport table 12 shown in FIG. 1 does not have a fixed end as shown in FIG. 4 but only has free ends at the positions of Q ₁ and Q ₄ at both ends. It has been described, in FIG. 1, and a stationary end fixed with fixing bolts conveying table 12 only at the location of Q _2, may be a free end position of Q _1.

That is, in this modified embodiment, the parts conveying apparatus of the present invention, the component transporting apparatus shown in FIG. 1, it is fixed end fixed with fixing bolts conveying table 12 only at the location of Q _2, Q ₁ and position of Q ₄ is a free end.

  In this case, the conveyance table 12 in FIG. 1 is schematically shown as in FIG. FIG. 9 is a schematic diagram conceptually showing the position of the antinodes of the vibration wave when n = 1 to 3 on the carriage 12 in this modification. In this case, the position of the antinode determined by the order n = 1 to 3 is shown in the schematic diagram of FIG.

In the case of this modification, the natural frequency f with respect to the vibration of the carriage 12 is represented by the following relational expression (4).
f = π (2n−1) ² / 8l ² × (EI / ρA) ^1/2 (4)
(Where f is the length, E is the Young's modulus, ρ is the density, n is the order, A is the cross-sectional area, and I is the cross-sectional secondary moment.)

8 ... Linear feeder drive unit,
10: Component conveying device,
12 ... transport table,
12a ... groove,
14a ... 1st vibration apparatus,
14b ... second vibration device,
16: Oscillator,
18: Amplifier.

Claims (2)

A linear transfer table for transferring parts by applying transfer vibrations;
An excitation device including a piezoelectric element that applies a release vibration to the transfer table to release clogging of components on the transfer table;
The piezoelectric element is provided so as to include a position where the amplitude of the vibration wave is maximum when the transfer table vibrates at a natural frequency in the transfer table;
A component conveying device characterized by the above. The length of the piezoelectric element in the length direction of the carrier is 40 to 70% of a half wavelength of the vibration wave of the natural vibration;
The component conveying apparatus according to claim 1, wherein:

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