TWI480540B - The appearance inspection of the workpiece and the appearance inspection method of the workpiece - Google Patents

Description

Appearance inspection device for workpiece and visual inspection method for workpiece

The present invention relates to an appearance inspection device for photographing a workpiece of a hexahedron and a workpiece of a hexahedron of the workpiece, and a method for inspecting the appearance of the workpiece.

In the visual inspection device for a chip-shaped electronic component such as a hexahedron-shaped resistor or capacitor (hereinafter referred to as a "workpiece"), a workpiece is placed on a transfer table made of a transparent body such as glass, and the transfer table is rotated and transported. A device for performing visual inspection by photographing each surface by a photographing means such as a camera is known.

In this case, the workpiece transfer table of the visual inspection device electrostatically adsorbs the workpiece and transports it by static electricity.

That is, the workpiece is first charged on a linear feeder that aligns the conveyance of the workpiece by vibration, and the workpiece is placed on the transfer table and transported to a specific working position, and the workpiece mounting surface of the transfer table is carried with the workpiece. In the case of static electricity of a reverse polarity, the workpiece is electrostatically adsorbed there (see Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-260594

However, the visual inspection device of the former workpiece has the following problems.

The first problem is that it is difficult to position the workpiece when it is transferred from the linear feeder to the transfer table. The workpiece on the transfer table has two faces in the transport direction, two faces in the up and down direction, and six faces on the left and right sides of the transport direction. In order to photograph these six faces, it is necessary to accurately photograph the six faces using a fixed photographing means. However, when the workpiece on the linear feeder is transferred to the transfer table, the workpiece is not limited to being transferred in a certain direction, and the posture of the workpiece is fixed by electrostatic adsorption after the transfer, so that the posture of each workpiece is generated during photographing. Subtle differences, and the possibility of reduced photography accuracy.

In addition, since the workpiece is transported while being charged in the linear feeder, the workpiece is adsorbed to the linear feeder due to the adsorption of static electricity during transport, and the transport speed is lowered. In the worst case, the workpiece is stopped. .

The second problem is that the electrostatic adsorption force after the workpiece is transferred is lowered. The workpiece placement surface of the transfer table and the workpiece always carry static electricity of opposite polarity, and sufficient attraction force can be ensured before the workpiece is transferred. However, as the workpiece is transferred, the contact point charge is contacted with the workpiece. Neutralization and its total amount is reduced. That is, the electrostatic attraction force acting on the workpiece placed on the transfer table is lowered.

Further, when the workpiece placement surface of the transfer table is charged, the charge is directed toward the workpiece by the ionizer provided on the upper surface of the transfer table, and the charge is a charge having a reverse polarity with respect to the charge that charges the workpiece. Therefore, a part of the electric charge transferred to the workpiece before the transfer table is neutralized, and in this case, the electrostatic adsorption force acting on the workpiece placed on the transfer table is lowered.

The third problem is the effect of static electricity on the workpiece. Moving by the aforementioned workpiece When the workpiece mounting surface is brought into contact with the workpiece, the charge is neutralized by the movement of the electric charge, and thus the electrostatic breakdown or characteristic deterioration of the workpiece occurs.

The present invention has been made in view of such a problem, and an object thereof is to provide an accurate positioning when transferring a workpiece from a linear feeder to a transfer table, which does not cause a decrease in electrostatic adsorption force after the workpiece is transferred, and no static electricity to the workpiece. Appearance inspection device for the affected workpiece and visual inspection method for the workpiece.

The present invention is a transparent body provided with a linear feeder that transports a workpiece having a hexahedral shape, a workpiece is transferred by a linear feeder at a transfer point, and is conveyed on a workpiece transfer arc while the workpiece is placed. The freely rotating circular transfer table is disposed between the linear feeder and the transfer table, and the transfer arrangement means for transferring the workpieces from the linear feeder to the transfer table to be arranged is arranged on the transfer table Below, a holding means for holding the workpiece placed on the transfer table and a photographing means for 6 sides of the workpiece on the photographing transfer table; the transfer arrangement means having a vibration-free portion provided between the linear feeder and the transfer table, And an arrangement guide arranged on the downstream side of the non-vibration portion, wherein the workpieces are arranged in a plan view and having a linear guide surface; the guide surfaces of the guide members are arranged to rotate the connection transfer point and the transfer table on a plane The straight line of the shaft forms an acute angle, and the wiring of the workpiece transfer arc is formed downstream of the transfer point, and the arrangement guide is located on the transfer table, and the arrangement of the arrangement guides is used to evacuate the gap between the arrangement guide and the transfer table. Visual inspection of the workpiece by means of suction.

The present invention is characterized in that the vacuum suction means has a vacuum source, and the appearance of the workpiece which is disposed on the arrangement guide, the one end is open to the gap between the transfer stage and the arrangement guide, and the other end is connected to the suction path of the vacuum source. Check the device.

The present invention is characterized in that the circular transfer table is an appearance inspection device for a workpiece composed of a transparent glass body.

The present invention is characterized in that the holding means is an appearance inspection device for a workpiece formed by a charging means that discharges charged ions toward the lower surface of the transfer table to charge the lower surface of the transfer table.

The present invention is characterized in that the holding means is constituted by a conductor disposed under the transfer table, and an appearance inspection device for applying a workpiece having a DC voltage to generate an electric field is applied to the conductor.

The present invention is characterized by an appearance inspection device for a workpiece that is larger than a conveyance speed of a workpiece of a linear feeder according to a conveyance speed of a workpiece of the conveyance table.

The present invention is characterized in that the guide surface of the guide member is arranged in a plan view, and an appearance inspection device for forming a workpiece having an acute angle of 75 to 88 degrees is formed on a straight line connecting the transfer point and the transfer table.

The present invention is characterized in that the method for inspecting a workpiece of a visual inspection device using a workpiece includes a step of conveying a workpiece having a hexahedral shape by a linear feeder, and passing the workpiece from the linear feeder through a vibration-free portion and arranging The step of transferring the guide to the transfer point on the circular transfer table, and arranging the workpiece by arranging the guide faces of the guides, and maintaining the workpieces placed on the transfer table by the holding means Workpiece transfer circle at the transfer table The step of transporting on the arc and the method of visual inspection of the workpiece in the step of photographing the six faces of the workpiece on the transfer table by means of photographing.

According to the present invention, the workpiece placed on the upper surface is held by the holding means disposed on the lower surface of the transfer table, whereby when the workpiece is transferred from the linear feeder to the transfer table, the holding and the alignment guide according to the holding means are used. The interval between the workpieces on the transfer table is approximately constant, and the posture is fixed in the transport direction, so that the workpiece can be accurately positioned. Therefore, it is possible to improve the accuracy of photographing by the photographing means, and it is possible to perform high-precision visual inspection. Further, the workpiece mounting surface of the workpiece or the transfer table is not charged, and the workpiece is held by the holding means disposed under the transfer table, and the electrostatic adsorption force is not lowered by the neutralization of the electric charge after the transfer table is transferred by the conventional transfer table. . Therefore, the processing capability of the visual inspection device is improved, and since the workpiece is not charged, there is no adverse effect such as electrostatic breakdown or deterioration of characteristics of the workpiece.

First embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 to Fig. 9 are views showing a first embodiment of an appearance inspection device for a workpiece and a visual inspection method for a workpiece according to the present invention.

First, the workpiece inspected by the visual inspection device of the workpiece will be described with reference to FIG. 2 .

In Fig. 2, a workpiece such as a capacitor or a resistor becomes a wafer part, and the workpiece W is formed into 6 faces. The body shape includes the main body Wd made of an insulator and the electrodes Wa and Wb formed of electric conductors formed at both end portions in the longitudinal direction of the main body Wd. When the visual inspection of the workpiece W is performed, the workpiece W is placed on the transfer table 2 to be described later, and the transfer table 2 is rotated in the direction of the arrow Z in FIG. 2 to transport the workpiece W. Next, the side surface on the opposite side of the paper surface is photographed by the photographing means 20 in the direction of the arrow A, the side surface in front of the paper surface is photographed in the direction of the arrow B, the upper surface is photographed in the direction of the arrow C, and the lower side is photographed in the direction of the arrow D, and the arrow E is photographed by the arrow E. The direction of the front of the photography, the direction of the arrow F behind the photography. At this time, it is possible to photograph the six faces of the workpiece W in a state in which the workpiece W is placed by using the transparent transfer table 2 made of glass.

Next, an appearance inspection device for the workpiece will be described. As shown in FIGS. 1 and 3, the visual inspection device 30 for a workpiece includes a linear feeder 1 that conveys a workpiece W, and the workpiece W is transferred by the linear feeder 1 at the transfer point 4x, and the workpiece W is placed. The circular transfer table 2, which is a transparent body that transports the workpiece transfer arc 5, transfers the workpiece W from the linear feeder 1 to the transfer table 2, and arranges the transfer arrangement means 21 to be arranged. The charging means 6A that functions as a holding means for holding the workpiece W placed on the transfer table 2 under the transfer table 2, and the six-sided imaging means of the workpiece W on the image transfer table 2 20.

The transfer alignment means 21 has a vibration-free portion 4 provided between the linear feeder 1 and the transfer table 2, and an arrangement guide 7 arranged on the downstream side of the non-vibration portion 4; the alignment guide 7 includes a guide surface 7a for arranging the workpiece W. This guide surface 7a is linear in plan view (viewed from above).

Further, the photographing means 20 includes a side camera unit 8, an inner camera unit 9, an upper camera unit 10, a lower camera unit 11, a front camera unit 12, and a rear camera unit 13, as will be described later.

Next, each component of the visual inspection device 30 of the workpiece will be described with reference to Figs. 1 to 4 .

1 is a plan view of an appearance inspection device for a workpiece W having a shape shown in FIG. 2, and FIG. 3 is an enlarged plan view of a region S surrounded by a broken line of FIG. 1, and FIG. 4 is based on FIG. A perspective view of the area S is seen in the direction of the arrow Y.

In FIG. 1, the linear linear feeder 1 is vibrated by a drive source (not shown), and the workpieces W of the unillustrated component feeders placed on the upstream side of the linear feeder 1 are arranged in a row. The vibration is transmitted in the direction of the arrow N.

The conveyance table 2 provided below the linear feeder 1 is made of transparent glass and is horizontal, and is rotated clockwise (in the direction of the arrow X in FIG. 1) around the rotation shaft 3 by a drive source (not shown). As shown in Fig. 4, the linear feeder 1 has a slight inclination toward the transfer table 2, and has a vibrating portion 4 which is inclined at the lower end portion and which does not vibrate at the lower end portion, and has a very large movement with the transfer table 2. It is connected with less gaps. Thereby, the workpiece W is gradually moved by the linear feeder 1 through the non-vibration portion 4, and is transferred to the transfer table 2.

In the vicinity of the outer edge portion of the upper surface of the transfer table 2, as shown by a broken line in FIG. 1, a workpiece transfer arc 5 having an arc centered on the rotary shaft 3 is formed, and the workpiece W is transferred from the non-vibration portion 4 to After the transfer station 2, as will be described later The action of the array guides 7 is arranged on the workpiece transport circular arc 5. Here, the workpiece transporting arc 5 is a target position assumed for arranging the workpiece W, and the workpiece transporting arc 5 can be visually observed without any identifiable stamp on the upper surface of the transporting table 2.

In addition, the charging means 6A functions as a holding means for holding the workpiece W placed on the transfer table 2. The charging means 6A is constituted by a slightly forward ionizer 6 provided at a position where the vibrating portion 4 is not provided. The ionizer 6 is provided directly below the conveying table 2, and discharges positive ions toward the lower surface of the conveying table 2 (hereinafter referred to as The "charge" is positively charged under the transfer table 2.

Further, among the above-described respective components, the transfer arranging means 21 is constituted by the non-vibration portion 4 and the guide 7 having the guide surface 7a.

In addition, in FIG. 3, the arrangement guide 7 which has the linear guide surface 7a has the clearance gap with the conveyance stage 2 in the upper side of the outer edge part side of the conveyance table 2. In FIG. 3, a straight line connecting the transfer point 4x and the rotation axis 3 of the transfer table 2 is indicated by a broken line K.

As shown in FIG. 3, the alignment guide 7 is formed such that the angle α between the guide surface 7a and the broken line K becomes an acute angle of 75 to 88 degrees, and the guide surface 7a is located in the conveyance direction of the workpiece W than the transfer point 4x. The merging point 7x of the downstream workpiece conveyance arc 5 is provided so as to be connected to the workpiece conveyance arc 5 . That is, when the straight line connecting the flow point 7x and the rotation axis 3 of the transfer table 2 is indicated by a broken line L, the angle ? between the broken line L and the guide surface 7a is 90.

Further, as shown in FIG. 1, a side camera unit constituting the photographing means 20 is provided along the rotation direction of the conveyance table 2 on the downstream side of the non-vibration portion 4. 8. The inner camera unit 9, the upper camera unit 10, the lower camera unit 11, the front camera unit 12, and the rear camera unit 13. By the photographing means 20, the workpiece W on the workpiece 5 is conveyed, and the respective faces of the workpiece W shown by the arrows A to F in Fig. 2 can be photographed and visually inspected. At this time, the conveyance direction of the workpiece W indicated by the arrow Z in Fig. 2 coincides with the rotation direction X of the conveyance table 2 of Fig. 1 .

Specifically, the side surface A on the opposite side of the paper surface is photographed on the side surface of the workpiece W, the inner side camera unit 9 photographs the side surface B in front of the paper surface, the upper surface of the upper camera unit 10 is photographed, and the lower side camera unit 11 photographs the lower side D, and the front side camera unit 12 Photography front E, rear camera unit 13 photographs rear F.

Further, as shown in FIG. 1, the discharge unit 14 as a discharge means is provided on the downstream side in the rotation direction of the conveyance table 2 by the photographing means 20. The workpiece W that has finished the visual inspection is discharged to the storage box (not shown) by the discharge unit 14 from the workpiece transport arc by the result of the visual inspection.

Next, the visual inspection method of the workpiece of the visual inspection device using the workpiece having such a configuration will be described in detail.

In Fig. 1, the workpiece W is placed in a component feeder (not shown) located on the upstream side of the linear feeder 1, and the workpiece W loaded into the component feeder is shaken by a linear feeder 1 which is vibrated by a driving source (not shown). The arrangement is arranged in a row, and the straight line is conveyed in the direction of the arrow N in FIG. At this time, the workpieces W are arranged such that the longitudinal direction thereof coincides with the conveyance direction, and the arrow Z in FIG. 2 serves as the conveyance direction of the workpiece W. That is, the direction of the arrow Z of FIG. 2 coincides with the direction of the arrow N of FIG.

Next, the action of the linear feeder 1 will be described in detail by means of FIG. 4 is a perspective view showing a state of the workpiece W conveyed by the linear feeder 1 in a region S surrounded by a broken line as seen from the direction of the arrow Y in FIG. Fig. 4 is a perspective view showing the position of the array guide 7 in a broken line in order to make the appearance of the workpiece W on the transfer table 2 easier to see. Further, with respect to the workpiece W, the workpieces on the respective constituent parts are represented by the workpieces W ₀ to W ₆ , regardless of the general workpiece of the place, which is represented by the workpiece W.

As shown in FIG. 4, the linear feeder 1 has a slight inclination toward the transfer table 2 located horizontally below, and the workpiece W advanced by the vibration of the linear feeder 1 pressing the subsequent workpiece W is continuous as indicated by W ₀ The front and rear directions are slightly lowered toward the transfer table 2. The linear feeder 1 vibrates, and when the linear feeder 1 is placed close to the position directly above the transfer table 2 when the workpiece W is transferred from the linear feeder 1 to the transfer table 2, the linear feeder 1 and the transfer table 2 may be in contact with each other. Then pick it up. In order to prevent this, a vibration-free portion 4 that does not vibrate is provided between the downstream end of the linear feeder 1 and the transfer table 2.

Further, due to the difference in the vibration of the linear feeder 1, the difference in the normal feed speed of the workpiece W also occurs in the linear feeder 1, so that the non-vibration portion 4 is interposed between the linear feeder 1 and the transfer table 2 This can make this transfer speed uniform.

However, the non-vibration portion 4 has the same inclination as the linear feeder 1, and has a slight gap between the upper portion and the upper surface of the transfer table 2. Vibration-free portion on the workpiece W with the linear feeder 1 4 likewise pressed forward subsequent workpiece, as shown before and after a continuous ₀ to W toward the conveying station 2 decreases a little bit.

Then, the workpiece W ₁ that has reached the downstream end of the non-vibration portion 4 is pressed by the workpiece W ₀ that is located later, and transferred to the transfer point 4x on the transfer table 2, and then transferred to the transfer table 2 by the rotation of the transfer table 2 The direction of the arrow X of Fig. 4. Here, if the length of the non-vibration portion 4 is too short, it becomes difficult to uniformize the conveyance speed, and conversely, if it is too long, the workpiece W may be stopped in the middle. In the embodiment of the present invention, since the length of the non-vibration portion 4 is eight times the dimension in the longitudinal direction of the workpiece, the workpiece W can be made uniform without stopping the workpiece W.

Further, as described above, the ionizer 6 is provided on the lower side of the transfer table 2, and the positive electric charge is discharged toward the lower surface of the transfer table 2, and the lower surface of the transfer table 2 is positively charged. In Figure 4, this positively charged charge is shown in + mode. Thus, by positively charging the lower surface of the transfer table 2, the workpiece W transferred to the transfer point 4x is adsorbed on the upper surface of the transfer table 2.

Next, the adsorption action of the workpiece W on the transfer table 2 will be described with reference to Figs. 5 to 7 .

6(a) and 6(b) are explanatory views showing the principle of electrostatic induction. An electrode Wa at one end portion in the longitudinal direction of the workpiece W is shown in Fig. 6(a). The electrode Wa is composed of a conductor, and in a normal state, as shown in FIG. 6(a), a positive electric charge indicated by + and a negative electric charge indicated by - exist in a random position. Fig. 6(b) shows the appearance when the positive electric charge is close to the electrode Wa from the left.

Here, the charged body T having a positive electric charge is brought close to it. At this time, the negative electric charge in the electrode Wa is attracted by the positive electric charge in the charged body T, and the negative electric charge is concentrated on the left side WaL side of the electrode Wa close to the charged body T. In addition, The positive electric charge in the electrode Wa repels the positive electric charge in the charged body T, and concentrates on the right side WaR side of the electrode Wa far from the charged body T. At this time, a negative electric charge is present on the WaL side on the left side and a positive electric charge is present on the WaR side on the right side. Further, since the electrode Wa is made of a conductor and the internal charge can be freely moved, there is no charge in the portion between the left side WaL and the right side WaR of the electrode Wa in Fig. 6(b). This phenomenon is called electrostatic induction.

Further, by electrostatic induction, between the negative electric charge concentrated on the left side WaL side of the electrode Wa and the positive electric charge in the charged body T, the attractive force indicated by an arrow G in Fig. 6(b) acts. Therefore, the electrode Wa is attracted to the charged body T. When the charged body T is away from the electrode Wa, the electric charge in the electrode Wa returns to the state of Fig. 6 (a) again. The same is true for the electrode Wb.

7(a) and 7(b) are explanatory views showing the principle of dielectric polarization. FIG. 7(a) shows the body Wd of the workpiece W at the center in the longitudinal direction. The body Wd is an insulator, and in a normal state, as shown in FIG. 7(a), a molecule having a positive electric charge indicated by + and a negative electric charge represented by - (a dotted ellipse) exists in a random s position.

Fig. 7(b) shows the appearance when the positive electric charge is approached to the body Wd from the left. Here, the charged body T having a positive electric charge is brought close to it. At this time, the negative charge in the body Wd is attracted by the positive charge in the charged body T, while the positive charge in the body Wd repels the positive charge in the charged body T. Therefore, the direction of the molecules in the body Wd is a negative electric charge on the left side WdL side of the main body Wd close to the electrified body T, and a positive electric charge is arranged on the right side WdR side of the main body Wd far from the electrified body T.

As shown in FIG. 7(b), the left side WdL side of the body Wd exhibits a negative electric power. Charge, the right side of the WdR side presents a positive charge. Further, since the body Wd is an insulator, the internal charge cannot move freely, and the molecules are arranged in a certain direction between the left side WdL and the right side WdR. This phenomenon is called dielectric polarization. Further, between the negative electric charge on the left side WaL side of the body Wd and the positive electric charge in the electrified body T by the dielectric polarization, the attractive force indicated by the arrow G in Fig. 7(b) acts. Therefore, the body Wd is attracted to the charged body T. When the charged body T is away from the body Wd, the molecules in the body Wd return to the state of Fig. 7(a) again.

Next, Fig. 5 shows a pattern in which the workpiece W transferred to the transfer point 4x is adsorbed on the upper surface of the transfer table 2 by electrostatic induction and dielectric polarization. In Fig. 5, the lower surface of the transfer table 2 is positively charged by the action of the ionizer 6. Since the glass of the material of the transfer table 2 is an insulator, the above-described dielectric polarization is caused by the positive electric charge existing on the lower surface of the transfer table 2, and the lower side of the inside of the transfer table 2 exhibits a negative electric charge, and the upper side presents a positive electric charge. . Further, similarly, the workpiece W ₂ transferred from the non-vibration portion 4 to the transfer point 4x on the transfer table 2 is electrostatically induced by the electrodes Wa and Wb, and is further separated by dielectric dipoles on the main body. The side exhibits a negative charge and a positive charge on the upper side.

In FIG. 5, the negative electric charge present on the lower surface side of the electrodes Wa, Wb and the main body Wd acts on the electrostatic adsorption force G indicated by the arrow between the positive electric charge existing on the lower surface of the transfer table 2, thereby The workpiece W ₂ is adsorbed on the upper surface of the transfer table 2. At this time, the lower surface of the workpiece W ₂ and the upper surface of the transfer table 2 are charged by electrostatic induction or dielectric polarization, and charging is not caused by the movement of electric charges. Therefore, neutralization of charges does not occur during adsorption, and adsorption force does not decrease after adsorption. In this manner, the workpiece W ₂ is conveyed in the direction of the arrow X by the rotation of the transfer table 2 while being adsorbed on the upper surface of the transfer table 2 .

Then, the workpiece W transferred from the non-vibration portion 4 to the transfer point 4x on the transfer table 2 is shown as the workpiece W ₂ and is transported to the transfer table 2 by the rotation of the transfer table 2 while being adsorbed to the transfer table 2 The direction of the arrow X.

In this case, according to the transport table 2 rotates conveyance speed ratio in accordance with the transport speed of the linear feeder 1 and the vibration portion 4 is larger, between the conveying table workpiece 2 (e.g. W between ₂ and _{W. 3)} into a spacer . Thus, by the space between the workpieces on the transfer table 2, the front camera unit 12 of Fig. 1 photographs the front surface E of the workpiece W shown in Fig. 2, and the rear camera unit 13 of Fig. 1 photographs the workpiece W shown in Fig. 2. When F is behind, it is possible to surely photograph the entire surface.

In other words, when the workpiece W is transferred to the transfer table 2 by the transfer point 4x and transported, the workpiece is electrostatically adsorbed in the section P in FIG. 3, and is rapidly accelerated to W ₂ → W ₃ → W ₄ to The conveyance speed of the conveyance stage 2 is expanded, for example, between W ₄ and W ₅ in the interval Q workpiece.

At this time, there is a slight gap between the non-vibration portion 4 and the transfer table 2, and the conveyance speed due to the rotation of the transfer table 2 is larger than the conveyance speed of the non-vibration portion 4, so that the workpiece W ₂ is not sufficiently adsorbed to the transfer table. In the case of 2, when the transfer portion 4x on the transfer table 2 is transferred by the non-vibration portion 4, the workpiece W ₂ is slightly jumped. In this case, the jump occurring in the workpiece W is different for each workpiece W, so that the interval between the workpieces W on the transport table 2 after the acceleration is different. On the other hand, according to the present invention, since the workpiece W _{2 is} sufficiently adsorbed to the transfer table 2, the workpiece W ₂ does not jump but is transferred from the time when the non-vibration portion 4 is transferred to the transfer point 4x on the transfer table 2. It is fixed to the transfer table 2. Therefore, the interval between the workpieces W after acceleration can be kept approximately constant.

However, a slight gap is provided between the array guide 7 having the linear guide surface 7a and the transfer table 2 directly above the transfer point 4x of the outer edge portion of the transfer table 2. As described above, in FIG. 3, when the straight line connecting the transfer point 4x and the rotating shaft 3 is a broken line K, the alignment guide 7 has an acute angle between the angle α between the guiding surface 7a and the broken line K, and is also on the guiding surface. The junction point 7x of the 7a downstream of the transfer point 4x is provided so as to be the wiring of the workpiece transfer arc 5. That is, when the straight line connecting the flow point 7x and the rotation axis 3 is indicated by a broken line L, the angle β between the broken line L and the guide surface 7a is 90°. Therefore, the transfer point 4x is positioned on the outer edge portion side of the transfer table 2 with respect to the workpiece transfer arc 5 . In other words, the conveyance direction (arrow X) of the workpiece W transferred to the transfer point 4x is in the direction toward the guide surface 7a, and the subtle difference in the posture of the workpiece W at the transfer point 4x can be corrected to be the same.

Next, the arrangement of the alignment guides 7 will be described with reference to Figs. 9(a) and 9(b).

Here, Fig. 9(a) shows the posture of the workpiece W _2E1 transferred to the transfer point 4x, and the case where the correct direction is slightly toward the left. The position of the transfer point 4x is the outer edge portion side of the transfer table 2 with respect to the workpiece transfer arc 5, and is the same as the track of the workpiece transfer arc 5 in the rotation direction of the transfer table 2 shown by the arrow X in Fig. 9(a). In the direction of the workpiece W _2E1 , the conveying direction is the direction toward the guiding surface 7a. Therefore, the workpiece W _2E1 is pressed against the guide surface 7a after abutting against the guide surface 7a like the workpiece W _2E2 . At this time, since the workpiece W _2E1 is adsorbed to the glass table 2 with a stronger force than the frictional force acting between the guide surface 7a, even if it is pressed against the guide surface 7a, the workpiece W can be decelerated without being decelerated. It is transported along the guide surface 7a.

Fig. 9(b) shows the posture of the workpiece W _2E3 that is transferred to the transfer point 4x, and the case where the correct direction is slightly toward the right. In this case, the conveyance direction of the workpiece W _{2E3 is} the direction toward the guide surface 7a, and the workpiece W _2E3 is pressed against the guide surface 7a after the workpiece W _2E4 abuts against the guide surface 7a, as in the case of W ₂ The form of the guide surface 7a is transported. In this way, the adsorption by the electric charge existing on the lower surface of the transfer table 2 and the action of the guide surface 7a make the interval between the transfer table 2 of the workpiece W approximately constant, and the posture in the transport direction can be made constant. The way to achieve a good positioning.

However, as described above, the conveyance speed due to the rotation of the conveyance table 2 is larger than the conveyance speed caused by the linear feeder 1 and the non-vibration portion 4, so that the positioned workpiece W is electrostatically adsorbed in the section P of FIG. In the state, the transport speed due to the rotation of the transport table 2 is rapidly accelerated to W ₂ → W ₃ → W ₄ , and the interval between the workpieces in the section Q is widened, for example, between W ₄ and W ₅ . Next, the workpiece W ₅ is simultaneously conveyed on the guide surface 7a in the same manner as the section P, and is gradually approached to the workpiece transporting arc 5. Next, the guide surface 7a reaches the contact with the workpiece conveying confluence arc 5 of 7x of the workpiece W transport direction _6, in section R consistent workpiece conveying direction of the arc 5, the workpiece W _6, is conveyed to leave the guide The direction of the face 7a. In other words, the workpiece W ₆ on the transfer table 2 acts on the electrostatic attraction force of the positive electric charge existing on the lower surface of the transfer table 2, so that the workpiece W ₆ is separated from the guide surface 7a while being adsorbed to the transfer table 2, After that, it is conveyed in a state of being placed on the workpiece transport arc 5 .

Further, as described above, in FIG. 3, the arrangement guide 7 and the transfer table 2 are provided with a slight gap directly above the transfer point 4x of the outer edge portion of the transfer table 2. As the L-direction arrow view of Fig. 3, the alignment guide 7 and the transfer table 2 near the transfer point 4x are shown in Fig. 16.

In FIG. 16, the workpiece W ₂ by the vibration system 4 is transferred to the portion of the workpiece after the transfer tray after the point 4x 2, table 2 rotated and conveyed by the transfer conveyance start. As described above, the workpiece W ₂ is transported along the guide surface 7a by the alignment action of the array guides 7 while being electrostatically adsorbed on the upper surface of the transfer table 2. In this case, the conveyance table 2 is formed in a circular shape by glass, and the conveyance table 2 has a slight warpage in the vicinity of the outer edge portion due to the work accuracy at the time of molding processing. When the warping table 2 having the warp rotates with a slight gap on the lower side of the array guide 7, as shown by the broken line in Fig. 16, the gap γ between the lower surface 7z of the guide member 7 and the upper surface 2s of the transport table 2 is γ. The size will vary. When the size of the gap γ is changed, particularly when the gap γ is small, the gap γ between the lower surface 7z of the array guide 7 and the upper surface 2s of the transfer table 2 faces the workpiece W ₂ placed on the upper surface 2s of the transfer table 2. Air is injected from the gap to blow against the workpiece W ₂ . Here, the workpiece W ₂ is adsorbed to the upper surface 2s of the transfer table 2 by the positive electric charge generated on the lower surface of the transfer table 2 by positively charging the lower surface of the transfer table 2 as described above.

However, when the air jetted by the gap γ is blown against the workpiece W ₂ , the workpiece W _{2 is} separated from the guide surface 7a depending on the pressure applied to the workpiece W ₂ at that time, or the posture of the workpiece W ₂ is not changed. The stability of the shackles.

In order to prevent this, the array guide 7 is provided with vacuum suction means 17, 18 for evacuating the gap γ formed between the lower surface 7z of the array guide 7 and the upper surface 2s of the transfer table 2. That is, the vacuum suction means 17, 18 has a vacuum source 17, and a suction passage 18 provided in the array guide 7, wherein one end 18a of the suction passage 18 opens in the gap γ, and the other end 18b is connected to the vacuum through the connecting line 17a. Source 17.

In Fig. 16, the vacuum source 17 and the suction passage 18 are arranged such that the gap γ between the lower surface 7z of the guide 7 and the upper surface 2s of the transfer table 2 is always evacuated in the directions of the arrows δ1, δ2, δ3. By the vacuuming, when the transfer table 2 is rotated and the size of the gap γ is changed, the air is ejected from the gap toward the workpiece W ₂ without being blown against the workpiece W ₂ . Therefore, the workpiece W ₂ is conveyed in a state of being electrostatically adsorbed stably on the upper surface 2s of the transfer table 2.

Here, as a comparison diagram of FIG. 16, the arrangement guide 70 which does not have the vacuum suction means 17 and 18 is shown in FIG. 17 when it is provided with the clearance gap with the conveyance stage 2. As shown by a broken line in Fig. 17, when the size of the gap γ between the lower surface 70z of the array guide 70 and the upper surface 2s of the transfer table 2 is changed, especially when the size of the gap γ is small, the air existing in the gap is compressed, so The workpiece W ₂ placed on the upper surface 2s of the rotating transfer table 2 is ejected by the gap in the direction of the arrow ε to be blown against the workpiece W ₂ . Since the workpiece W _{2 is} separated from the guide surface 70a by the pressure of the air, even if the transfer table 2 rotates and the workpiece W ₂ reaches the junction point 7x of FIG. 3, the workpiece W ₂ cannot be placed on the workpiece conveyance shown in FIG. On the arc 5, the workpiece positioning with high precision of the object of the present invention cannot be achieved. Further, even in the case where the pressure of the air is not so large that the workpiece W _{2 is} separated from the guide surface 70a, the posture of the workpiece W ₂ becomes unstable near the guide surface 70a, and the object of the present invention cannot be achieved after all. The positioning of the workpiece with good precision.

On the other hand, according to the present invention, the gap γ between the lower surface 7z of the array guide 7 and the upper surface 2s of the transfer table 2 is always evacuated, so that even if the air is ejected by the gap γ, the workpiece W ₂ is not blown, and the workpiece can be made. W ₂ is arranged stably on the transfer table 2.

When the workpiece W is transported in a state of being placed on the workpiece transport arc 5 in FIG. 3, the workpiece W reaches the photographing means 20, and the side camera unit 8, the inner camera unit 9, and the upper surface of the photographing means 20 are used. The camera unit 10, the lower camera unit 11, the front camera unit 12, and the rear camera unit 13 are visually inspected by the respective directions of the directions indicated by the arrows A to F in Fig. 2 . In this case, the positioning of the workpiece W is accurately performed by the action of the adsorption and the guide surface 7 due to the electric charge existing on the lower surface of the transfer table 2, so that the imaging accuracy by the photographing means 20 is improved. The workpiece W that has finished the visual inspection reaches the discharge unit 14 and is discharged toward the storage box (not shown) in response to the result of the visual inspection.

When the workpiece W is discharged from the discharge unit 14, for example, compressed air can be ejected from the inner peripheral side of the transfer table 2 to the side surface B in front of the paper surface of FIG. 2, and the workpiece W can be led to the outer peripheral side of the transfer table 2 and guided to the storage box. The workpiece W in the storage box has the state shown in FIGS. 6(b) and 7(b) because of the positive electric charge present on the transfer table 2, but returns to the positive charge. The state of Fig. 6 (a) and Fig. 7 (a). In the meantime, the workpiece W itself does not It will generate electricity due to static electricity.

As described above, in the present embodiment, the workpiece W is adsorbed to the transfer table 2 by static electricity. However, it is explained that the workpiece W does not cause electrostatic breakdown or characteristic deterioration due to static electricity, as shown in Figs. 8(a) and 8(b). Wait.

(a) of FIG. 8 shows a pattern of a power line generated by positive electric charges existing on the lower surface of the transfer table 2 when the workpiece W is placed on the upper surface of the transfer table 2 and the lower surface of the transfer table 2 is positively charged. As shown in Fig. 8(a), the power line starts with a positive charge and ends with a negative charge. In this case, since the negative electric charge is considered to exist at infinity, the electric power line E1 starts from the positive electric charge existing on the lower surface of the transfer table 2, and passes through the transfer table 2 and the workpiece W to face upward. Further, although there is a power line that is directed downward or leftward from the positive electric charge, it is not shown in the present invention regardless of the present invention. At this time, the electrodes Wa and Wb of the workpiece W are electrostatically induced, or the body Wd is dielectrically polarized to present a negative charge under the respective lower portions, while the upper portions respectively exhibit positive charges. At this time, the electrodes Wa and Wb are electric conductors on which a positive charge is accumulated and a negative charge is accumulated underneath. Therefore, the electric power line E2 is generated inside the electrodes Wa and Wb by these charges. Its direction is initiated by the positive charge present above and back to the negative charge present below.

That is, the electric power lines E1 and E2 in the electrodes Wa and Wb are opposite to each other and cancel each other, and as shown in FIG. 8(b), the electric wires are not present in the electrodes Wa and Wb. The electric power line thus divided by the electrodes Wa and Wb is denoted by E1' in Fig. 8(b). In this state, since the power lines are not present in the electrodes Wa and Wb, the electrodes Wa and the electrodes Wb have the same potential. that is, No voltage is applied between the electrode Wa and the electrode Wb, and electrostatic discharge or deterioration of characteristics of the workpiece is not caused.

However, the workpiece W is transferred from the non-vibration portion 4 to the transition state of the transfer table 2, and the electric charges in the electrodes Wa and Wb of the workpiece W may be moved to the respective electrodes due to electrostatic induction of electric charges existing on the lower surface of the transfer table 2. In the meantime, the electrodes Wa and Wb are repeatedly brought into contact with or away from the vibrating portion 4 and the transfer table 2. Thus, when the electric charges in the electrodes Wa and Wb move between the electrodes Wa and Wb and the outside, the electrostatic breakdown caused by the discharge may be caused. In this case, the non-vibration portion 4 is configured by a material having a high electric resistance value such as an insulator similar to the transfer table 2, so that no movement of electric charges occurs between the electrodes Wa and Wb.

Further, in the above embodiment, an example is described in which the lower surface of the transfer table 2 is positively charged, but it may be negatively charged as necessary. In addition, although the conveyance stage 2 is shown by the glass material, the material of the conveyance stage 2 is only transparent, and is not limited to glass.

Second embodiment

Hereinafter, a second embodiment of the present invention will be described with reference to Figs. 10 to 15 .

In the second embodiment of the present invention shown in Figs. 10 to 15, the charging means 6A is disposed below the transfer table 2, and the conductive plate (conductor) 15 is disposed below the transfer table 2. The other configuration is roughly the same as that of the first embodiment shown in Figs. 1 to 9 .

The second embodiment shown in Figs. 10 to 15 and Figs. 1 to 9 The same portions as those in the first embodiment are denoted by the same reference numerals and will not be described in detail.

Here, FIG. 10 is a perspective view of a region S surrounded by a broken line as seen from the direction of the arrow Y in FIG. 1, corresponding to FIG. In Fig. 10, on the lower side of the transfer table 2, instead of the charging means 6A composed of the ionizer 6, the conductive plate 15 formed of the conductor is disposed with a very small gap from the lower surface of the transfer table 2. . The conductive plate 15 has a planar shape, as shown in Fig. 12, and its surface 15a is approximately parallel to the transfer table 2. Further, a DC voltage is applied to the conductive plate 15 to which the DC power source 16 is connected to constitute an electric field generating means. The arrangement of the conductive plates 15 is shown by FIG. Fig. 11 is an enlarged plan view showing a region S surrounded by a broken line of Fig. 1, corresponding to Fig. 3. In Fig. 11, the conductive plate 15 is elongated in the horizontal direction, and the transfer table of the workpiece transfer arc 5 and the guide surface 7a of the array guide 7 corresponding to the transfer table 2 from the transfer point 4x to the workpiece W The lower side of the second side is disposed so as to convey the arc 5 along the workpiece of the workpiece W in the normal direction.

Next, the action of the second embodiment of the present invention will be described below with reference to Figs. 10 to 15 .

In Fig. 11, the workpiece W transported in one row by the vibration of the linear feeder 1 is transferred to the transfer point 4x on the transfer table 2 by the conductive plate 15 connected to the DC power source 16. The electrostatic induction and the dielectric polarization caused by the action of the electric charge are adsorbed on the upper surface of the transfer table 2.

The appearance of this adsorption is shown in Figure 12. In Fig. 12, the conductive plate 15 is disposed such that a small DC gap is applied to the lower surface of the transfer table 2, and a positive DC voltage is applied to the conductive plate 15 to which the DC power source 16 is connected. Therefore, The conductive plate 15 exhibits a positive charge.

The dielectric charge is caused by the action of the positive electric charge in the same manner as in FIG. 5, and the inside of the transfer table 2 opposed to the conductive plate 15 exhibits a negative electric charge on the lower surface side and a positive electric charge on the upper surface side. Further, in the same manner, the workpiece W ₂ transferred from the non-vibration portion 4 to the transfer point 4x on the transfer table 2 is electrostatically induced by the electrodes Wa and Wb, and is further separated by dielectric polarization on the body Wd. The lower side presents a negative charge and a positive charge on the upper side.

Next, between the negative charges appearing on the lower surfaces of the electrodes Wa, Wb and the body Wd and the positive charges of the conductive plates 15, there is an electrostatic attraction force G indicated by an arrow, whereby the workpiece W ₂ is adsorbed to the transfer table 2 The upper state is conveyed in the direction of the arrow X by the rotation of the transfer table 2.

In this case, as in the first embodiment shown in FIGS. 8(a) and 8(b), since the workpiece W itself is not charged by static electricity, the workpiece W does not cause electrostatic breakdown or deterioration in characteristics.

Further, in the description of the above embodiment, the case where the surface of the conductive plate 15 is approximately parallel to the surface of the transfer table 2 has been described, but the positional relationship between the surface of the conductive plate 15 and the surface of the transfer table 2 is not limited thereto. An enlarged view of the L-direction arrow view of Fig. 11 is shown in Fig. 13, and a pattern of electric power lines starting from the positive electric charge of the conductive plate 15 is shown in Fig. 13.

As shown in FIG. 13, the power line penetrates the transfer table 2 and the workpiece W to cause electrostatic induction and dielectric polarization, and a negative charge is generated on the lower surface of the workpiece W, and a positive charge is generated on the upper surface of the workpiece W. Here, for the sake of simplicity, the electric charge generated in the transfer table 2 by the dielectric polarization is not shown.

As shown in FIG. 13, the power line from the positive charge on the conductive plate 15 Among them, a positive charge originator (Ex in the drawing) existing in the vicinity of the end surface 15x of the conductive plate 15 has a property of being bent toward the side where the electric charge does not exist, that is, toward the outer side of the conductive plate 15. Therefore, instead of the configuration shown in FIG. 13, the conductive plate 15 may be disposed such that the surface 15a and the transfer table 2 are at a substantially right angle as shown in FIG. In this case, the conductive plate 15 is elongated in the horizontal direction, and is disposed on the lower side of the transfer table 2 corresponding to the guide surface 7a of the array guide 7 so that the longitudinal direction becomes the workpiece 5 which is approximately parallel to the workpiece W. Mode configuration.

In FIG. 14, a power line from a positive electric charge in the vicinity of the end surface 15x among the electric power lines starting from the positive electric charge of the conductive plate 15 passes through the transfer table 2 and the workpiece W. Therefore, similarly to the case shown in FIG. 13, a negative charge is generated on the lower surface of the workpiece W by electrostatic induction and dielectric polarization, and a positive charge is generated on the upper surface of the workpiece W.

Further, as shown in FIG. 15, a conductive plate 15 having a cross section having an L shape may be provided. In this case, the two surfaces 15b and 15c crossing the conductive plates 15 may be arranged such that the surface 15b is approximately orthogonal to the transfer table 2, so that the surface 15c may be arranged approximately parallel to the transfer table 2. In this case, the conductor 15 is elongated in the horizontal direction, and is disposed on the lower side of the transfer table 2 corresponding to the guide surface 7a of the alignment guide 7, and the longitudinal direction is a workpiece parallel to the workpiece W. Mode configuration.

In FIG. 15, since the power lines do not intersect each other, the power line from the positive electric charge from the positive electric charge of the conductive plate 15 passes through the transfer line 2 and the workpiece W, which are derived from the positive electric charge in the vicinity of the end surface 15x. Therefore, as in the case of FIG. 13, the lower surface of the workpiece W is produced by electrostatic induction and dielectric polarization. A negative charge generates a positive charge on top of the workpiece W.

Further, in the description of the second embodiment, an example in which the conductive plate 15 is positively charged is shown, but it may be necessary to be negatively charged.

1‧‧‧Linear feeder

2‧‧‧Transportation station

3‧‧‧Center axis of the transfer table

4‧‧‧No vibration department

4x‧‧‧ Transfer Point

5‧‧‧Workpiece transfer arc

6‧‧‧Ionizer

6A‧‧‧Electrical means

7‧‧‧ Alignment guides

7a‧‧‧ Guide surface

7x‧‧ ‧ confluence point

8‧‧‧ Side Camera Department

9‧‧‧Internal Camera Department

10‧‧‧Top Camera Department

11‧‧‧ below camera department

12‧‧‧ Front Camera Department

13‧‧‧Back Camera Department

14‧‧‧Exporting Department

15‧‧‧ Conductive plate

17‧‧‧Vacuum source

17a‧‧‧Connected line

18‧‧‧sucking pathway

18a‧‧‧One end of the suction channel

18b‧‧‧The other end of the suction channel

20‧‧‧Photography

21‧‧‧Transfer arrangement

30‧‧‧Appearance inspection device for workpieces

W‧‧‧Workpiece

Wa, Wb‧‧‧ electrode of the workpiece

Wd‧‧‧Workpiece ontology

Fig. 1 is a plan view of an appearance inspection device for a workpiece according to a first embodiment of the present invention.

Figure 2 is a perspective view showing the workpiece.

Figure 3 is an enlarged plan view showing the area S of Figure 1.

Figure 4 is a perspective view of the area S of Figure 1 as seen from the direction of the arrow Y.

Fig. 5 is a schematic view showing the adsorption of the workpiece to the transfer table according to the first embodiment of the present invention.

6(a) and 6(b) are explanatory views showing the principle of electrostatic induction according to the first embodiment of the present invention.

7(a) and 7(b) are explanatory views showing the principle of the inductive polarization according to the first embodiment of the present invention.

8(a) and 8(b) are explanatory views showing power lines according to the first embodiment of the present invention.

Fig. 9 (a) and Fig. 9 (b) are explanatory views showing the operation of the array guide according to the first embodiment of the present invention.

Fig. 10 is a perspective view of an appearance inspection device for a workpiece according to a second embodiment of the present invention, and corresponds to Fig. 4 of the first embodiment.

Fig. 11 is an enlarged plan view showing the appearance inspection device of the workpiece according to the second embodiment of the present invention.

Fig. 12 is a schematic view showing the adsorption of the workpiece to the transfer table in the second embodiment of the present invention.

Fig. 13 is an explanatory view showing a power line according to a second embodiment of the present invention.

Fig. 14 is an explanatory view showing a power line according to a second embodiment of the present invention.

Fig. 15 is an explanatory view showing a power line according to a second embodiment of the present invention.

Fig. 16 is a view showing a vacuum suction means provided on the array guide, and an arrow view in the L-direction direction of Fig. 3.

Fig. 17 is a view showing the relationship between the arrangement guide and the transfer table in the same direction as Fig. 16.

1‧‧‧Linear feeder

2‧‧‧Transportation station

4‧‧‧No vibration department

4x‧‧‧ Transfer Point

5‧‧‧Workpiece transfer arc

7‧‧‧ Alignment guides

7a‧‧‧ Guide surface

7x‧‧ ‧ confluence point

W ₀ ~W ₉ ‧‧‧Workpiece

K, L‧‧‧ dotted line

,,β‧‧‧ angle

P, Q, R‧‧‧

N, X‧‧ arrow

21‧‧‧Transfer arrangement

Claims (7)

An appearance inspection device for a workpiece, comprising: a linear feeder for conveying a workpiece having a shape of a hexahedron; the workpiece is transferred by a linear feeder at a transfer point, and is placed on a workpiece transfer arc in a state where the workpiece is placed A freely rotating circular transfer table formed by a transparent body that is transported is disposed between the linear feeder and the transfer table, and transfers the workpiece from the linear feeder to the transfer table to arrange the transfer arrangement a holding means for holding the workpiece placed on the transfer table, and a photographing means for the six faces of the workpiece on the photographing transfer table; the transfer arrangement means is provided on the linear feeder and the transfer table The non-vibrating portion between the two, and the downstream side of the non-vibrating portion, the alignment guide having the linear guiding surface is viewed from the plane in which the workpieces are arranged; the guiding surface of the guiding guides is transferred on the plane The point is at an acute angle to the straight line of the rotating shaft of the conveying table, and the wiring of the workpiece conveying arc is formed downstream of the transfer point, the alignment guide is located on the conveying table, and the guiding guides are arranged and arranged in the arrangement of the guiding guides. a vacuum suction means for evacuating the gap; the vacuum suction means has a vacuum source, and is disposed on the alignment guide, one end is open to the gap between the transfer table and the alignment guide, and the other end is connected to the vacuum source In the suction passage, the gap between the guide and the transfer table is vacuum-pumped by the vacuum means, and even if the size of the gap is changed while the transfer table is rotated, the air is not ejected from the gap toward the workpiece placed on the transfer table. The visual inspection device for a workpiece according to the first aspect of the invention, wherein the circular transfer table is formed of a transparent glass body. The visual inspection device for a workpiece according to the first aspect of the invention, wherein the holding means is constituted by a charging means for discharging charged ions toward the lower surface of the transfer table to charge the lower surface of the transfer table. The visual inspection device for a workpiece according to the first aspect of the invention, wherein the holding means is constituted by a conductor disposed under the transfer table, and a DC voltage is applied to the conductor to generate an electric field. The visual inspection device for a workpiece according to the first aspect of the invention, wherein the conveying speed of the workpiece according to the conveying table is larger than the conveying speed of the workpiece according to the linear feeder. The visual inspection device for a workpiece according to the first aspect of the invention, wherein the guide surface of the guide member is arranged in a plan view, and forms an acute angle of 75 to 88 degrees with respect to a straight line connecting the transfer point and the transfer table. A method for inspecting an appearance of a workpiece, which is characterized in that the method for inspecting a workpiece of an external appearance inspection device of the workpiece of claim 1 is provided with a step of conveying a workpiece having a hexahedral shape by a linear feeder The workpiece from the linear feeder is moved through the vibration-free part and the alignment guide The step of arranging the workpieces by arranging the guide faces of the guides while carrying the transfer points on the circular transfer table, and maintaining the workpieces placed on the transfer table by the holding means, so that the workpieces are on the transfer table The step of transporting the workpiece on the circular arc and the step of photographing the six faces of the workpiece on the transfer table by the photographing means.