JP2009184764A - Conveying system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying system and a conveyor device which can inhibit electrostatic charge during conveyance of insulating work pieces. <P>SOLUTION: This conveying system 100 conveys a glass substrate W mounted on a tray 1, and has rollers 25 and the tray 1. A plurality of rollers 25 are arranged along the conveying direction. The tray 1 is mounted with an insulating glass substrate W. At least mutual contact areas of the tray 1 with the rollers 25 (outer flange 11 and rollers 25) have conductivity, and the contact areas are grounded. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transfer system for transferring an insulating work.

For example, in a manufacturing process or the like of a thin display device, a technique for conveying an insulating article (work) represented by a glass substrate is required. And as a device which conveys such a work, the conveyor device which arranged a plurality of rollers in the conveyance direction is generally used.
When the glass substrate is transported in the conveyor device, static electricity may be generated on the substrate surface due to friction with the rollers. In that case, dust or dust (so-called particles) in the air adheres to the surface of the substrate, or a malfunction occurs in the electric circuit of the substrate.
In order to solve such a problem, a technique for removing electricity from a substrate has been proposed. For example, in Patent Document 1, at least a portion of the roller that contacts the substrate is formed of a conductive soft member, and the conductive flexible material is grounded.
JP 2002-274642 A

However, the conventional conveyor device has the following problems.
That is, even if a conductive roller is used, only the contact portion between the roller and the substrate can be neutralized. That is, the degree of charge removal is not sufficient, and thus the above-described problem cannot be avoided.
In recent years, since the size of glass substrates is increasing, there is a concern that the amount of charge further increases.
The present invention solves the above-described conventional problems, and an object of the present invention is to provide a transport system capable of suppressing charging when transporting an insulating workpiece.

A transport system according to a first aspect is a transport system for transporting an insulating work, and includes a tray and a plurality of rollers. The tray places the work. The plurality of rollers are arranged side by side in the transport direction to transport the tray. In the roller and the tray, at least the mutual contact portion has conductivity. The contact part is grounded.
In this system, the static electricity generated by the friction between the tray and the roller is more reliably discharged when the tray is transported. That is, charging when an insulating work is conveyed is suppressed. As a result, problems such as particles being attracted to the work are unlikely to occur.

In the transport system according to a second aspect, in the first aspect, the tray is formed of a conductive material.
In this system, since the tray is formed of a conductive material, it is possible to discharge static electricity stored in a portion other than the portion where the roller is in direct contact.

According to a third aspect of the present invention, in the conveyance system according to the first or second aspect, the roller is formed of a resin containing a predetermined amount of a conductive material.
Since this system uses resin rollers, it is difficult to damage the tray during transportation.

According to a fourth aspect of the present invention, in the conveyance system according to the third aspect, the roller contains 1 to 50 wt% of a conductive material.
In this system, the conductivity required for the roller is sufficiently ensured in order to suppress the charge amount of the workpiece.

According to a fifth aspect of the present invention, in the conveyance system according to the fourth aspect, the roller contains 1 to 30 wt% of a conductive material.
In this system, the conductivity required for the roller is sufficiently ensured in order to suppress the charge amount of the workpiece.

  According to the transport system of the present invention, it is possible to suppress charging when transporting an insulating work.

A transport system 100 according to an embodiment of the present invention will be described below with reference to FIGS.
[overall structure]
As shown in FIGS. 1 and 2, the transport system 100 places a thin plate-like work on a transport tray 1 (hereinafter referred to as “tray 1”), and reaches a predetermined position along the transport path. It is a device to convey. Examples of the thin plate-like workpiece conveyed by the conveyance system 100 of the present embodiment include a plate-like workpiece used for an electronic display (liquid crystal display, plasma display, etc.), a resin plate used for an organic EL, and the like.
[Conveyor 20]
As shown in FIGS. 1 and 2, the transport conveyor 20 includes a support frame 21, rollers 25, and a drive device (not shown).

The support frame 21 is formed of a conductive material, and includes a main body 21a that stores a driving force transmission mechanism of the roller 25, and support legs 21b that support the main body 21a above the floor surface.
A plurality of rollers 25 are arranged along the transport direction. Specifically, the roller 25 is composed of a pair of roller groups arranged along the transport direction. Each roller 25 is attached to the main body 21 a via a conductive shaft 26. The shaft 26 is rotatably supported via a bearing (not shown) arranged in the main body 21a, and is further connected to a driving device (not shown) arranged in the main body 21a. The roller 25 is made of carbon-filled MC nylon. In this embodiment, the roller 25 has a predetermined conductivity by containing 1 to 50 wt% of carbon black.

[Transport tray 1]
FIG. 4 is a perspective view showing a configuration of an embodiment of the transfer tray 1, and FIG. 5 is a top view of the tray 1.
The tray 1 is used for placing and transporting a thin plate-like workpiece. The tray 1 mainly includes a rectangular outer frame 2 and a plurality of crosspieces 4 spanned between frame members facing the outer frame 2. Here, description will be made using a glass substrate W as a thin plate-like workpiece.
The outer frame 2 is composed of four frame members 2a. The frame member 2a in the present embodiment uses an aluminum extrusion material having a constant plate thickness, and the frame member 2a is composed of two long side frame members and two short side frame members.
The frame member 2 a includes an outer flange (contact portion) 11 and an inner flange 12 formed at a position higher than the outer flange 11, and an inclined portion 13 is provided between the outer flange 11 and the inner flange 12. It has been. The inner flange 12 extends inward from the upper end portion of the inclined portion 13, and the outer flange 11 extends outward from the lower end portion of the inclined portion 13. The inclined portion 13 is angled so as to have a shape that expands downward when the outer frame 2 is formed.

A plurality of the crosspieces 4 are spanned between the opposing frame members 2 a of the outer frame 2 to form a placement portion for the glass substrate W. The crosspiece 4 is made of an aluminum extruded material having a certain thickness.
The crosspiece 4 has a plurality of mounting pins 4 a for supporting the glass substrate W. The mounting pin 4a is made of polyether ether ketone resin (PEEK) having high wear resistance, and even if the glass substrate W is repeatedly mounted, dust due to wear hardly occurs and the glass substrate W is contaminated. do not do. Further, since there are few contact surfaces with the glass substrate W, charging due to friction or peeling between the tray 1 and the glass substrate W can be suppressed.
When the tray 1 is transported by the transport conveyor 20, the left and right sides are placed on each roller group of the rollers 25 as shown in FIG. 1. More specifically, the outer flange 11 of the tray 1 is placed on a roller 25 as shown in FIG.

In this state, when a driving device (not shown) rotates the roller 25, the tray 1 is conveyed on the plurality of rollers 25.
In the above structure, the support frame 21 is grounded by the support legs 21b. As a result, the roller 25 is grounded via the shaft 26 and the support frame 21. Further, the tray 1 is also placed on the roller 25 and is grounded via the roller 25, the shaft 26, and the support frame 21. With the above grounding structure, charging due to contact between the tray 1 and the roller 25 during conveyance is suppressed.
In this system, since the tray 1 is formed of a conductive material, it is possible to discharge static electricity stored in areas other than the part where the roller 25 directly contacts.
In this system, since the resin roller 25 is used, it is difficult to damage the tray during conveyance.

In order to confirm the charging suppression effect of the insulating work in the transport system 100 of the present invention, an experiment was conducted on the following items.
In the following experiment, a tray durability test apparatus having a one-way conveyance distance of 0.5 m and a small test tray were used, and measurement was performed in an environmental test room at room temperature of 25 degrees and humidity of 45%. Further, a 240 mm or 400 mm glass substrate was used as the insulating work. In addition, the amount of charge on the glass substrate was measured with a surface potential meter, and the conveyance speed was measured with a small test tray and a scale (25 mm pitch) attached to the glass substrate and a photosensor. Further, the number of rotations of the roller was measured by a pulse disk and a photo sensor integrally attached to the roller rotation shaft.
The test tray is composed of the same components as the tray described above, except for the dimensions.
(1) Measurement of charging potential when a glass substrate is transported alone (prior art)
First, when a glass substrate is brought into contact with a conventional transfer method, that is, when a glass substrate is brought into contact with a grounded conductive roller (for example, MC-containing nylon), a charging potential generated on the glass substrate was measured.

Specifically, after the glass substrate is placed on the roller, the static electricity is sufficiently removed, and the glass substrate is repeatedly reciprocated according to the conditions with and without the roller acceleration / deceleration. The charging potential (V) at the lower surface was measured. Here, the speed curve without acceleration / deceleration is as shown in FIG. 7, and the speed curve with acceleration / deceleration is as shown in FIG. That is, when there is no roller acceleration / deceleration, slip occurs between the roller and the glass substrate, and when there is acceleration / deceleration, there is no slip between the roller and the glass substrate, so that the roller is conveyed without being rubbed. I understand that.
As a result, as shown in FIG. 6, it was confirmed that the charging potential of the glass substrate increases in proportion to the transport distance regardless of the measurement conditions (with or without acceleration / deceleration). . That is, when the glass substrate is transported in contact with the roller, it has been confirmed that even if the roller in contact with the glass substrate is formed of a conductive material and further grounded, there is no sufficient static elimination effect. As long as the glass substrate to be conveyed is insulative, charging due to friction with the roller cannot be avoided. Even if an attempt is made to remove static electricity using a grounded conductive roller, the roller actually This is thought to be due to the fact that only the contact portion between the glass substrate and the glass substrate can be removed. In other words, the above-described conventional transport method cannot sufficiently suppress the charging of the glass substrate.

(2) Measurement of charged potential for each type of conveyed product (Comparison between the present invention and the prior art)
Next, with respect to the grounded conductive roller, the charging potential (V) at the upper surface and the lower surface of each glass substrate was measured for each type of conveyed product. There are the following three types of conveyed items.
(A) Glass substrate alone (prior art)
(B) Glass substrate placed on an aluminum tray (present invention)
(C) Glass substrate placed on SUS tray (present invention)
Here, the speed curve when the glass substrate alone (glass size: 400 mm) is conveyed is as shown in FIG. 7, the glass substrate placed on the SUS tray (glass size: 240 mm), and the glass substrate placed on the aluminum tray (glass size). : 240 mm), the speed curves when transporting are as shown in FIG. 10 (a) and FIG. 10 (b), respectively.
As a result, as shown in FIG. 9, it is confirmed that the charged potential of the glass substrate is extremely small when the glass substrate is transported using the SUS tray and the aluminum tray as compared with the case of transporting the glass substrate alone. I was able to. And when a conveyance distance becomes large, the difference is remarkable. In this way, in order to suppress the charge of the object to be transported when transported on a grounded conductive roller, the glass substrate is transported using a tray made of a conductive material rather than transporting the glass substrate alone. It was confirmed that this is advantageous.

(3) Measurement of charging potential according to material of tray and roller (comparison between the present invention and other technologies)
Next, on the premise that the glass substrate (glass size: 240 mm) is transported using the tray, the charging potential (V) of the glass substrate was measured for each combination of the presence of the tray and roller conductivity. There are the following three combinations.
(A) Combination of UPE (ultra high molecular weight polyethylene) roller (insulating) and aluminum flange (conductive) (technology other than the present invention)
(B) Combination of carbon-containing MC nylon roller (conductive) and aluminum flange (conductive) (present invention)
(C) Combination of MC nylon roller with carbon (conductivity) and flange (insulation) with PVC tape on the surface (technology other than the present invention)
With respect to the above three examples, the charging potential (V) between the upper surface and the lower surface of the glass substrate placed on the tray was measured. Here, the portion of the tray that contacts the roller is a flange (corresponding to the outer flange 11 in FIG. 4).

As a result, as shown in FIG. 11, it was confirmed that the charged potential of the glass substrate was extremely small when the roller and the flange were conductive members, that is, in the case of the combination (b). On the other hand, when (a) and (c) were combined, it was confirmed that the charged potential of the glass substrate was larger than that in (b).
Based on the above results, it is effective to make both the tray and the roller (at least the contact portion) conductive in order to suppress the charging potential when the insulating glass substrate is transported using the tray. Was confirmed.
(4) Measurement of the charged potential when the glass substrate is placed on an aluminum tray and transported (the present invention)
Finally, the glass substrate was placed on an aluminum tray, and the charged potential (V) of the glass substrate was measured when the glass substrate was transported while changing the transport speed and acceleration / deceleration. Specifically, as in the velocity curves shown in FIGS. 13 to 16, acceleration / deceleration is 15 m / min (see FIG. 13), acceleration / deceleration is 30 m / min (see FIG. 14), and acceleration / deceleration is 45 m / min. The charged potential (V) was measured on the upper and lower surfaces of the glass substrate when transported under the conditions of Yes (see FIG. 15), 45 m / min · no acceleration / deceleration (see FIG. 16).

As a result, as shown in FIG. 12, it can be confirmed that the increase in the charging potential can be greatly suppressed when measured under any condition as compared with the case where the glass is transported alone (see FIG. 6). It was.
When the insulating work is conveyed by a roller such as a conveyor device by the above measurements (1) to (4), the insulating work is placed on the conductive tray, and the conductive roller is grounded to the tray. It was confirmed that the method of transporting by contacting is effective.
The tray mounting pins used in (2) to (4) are all made of PEEK and are insulators.
(5) Measurement of charging potential when placing glass substrate on tray (present invention)
In actual use, there is a step of putting the glass in and out of the tray. That is, the glass substrate is repeatedly contacted and separated from the tray mounting pin as the protruding pin or the roller ascends and descends from the lower side of the tray.

Therefore, the charging potential (V) of the glass substrate was measured by changing the materials of the mounting pin, the protruding pin, and the roller with respect to the charging potential when the glass substrate was placed on the tray. In particular,
(A) Combination of PEEK (polyetheretherketone resin) mounting pin and protrusion pin (insulating) and carbon-containing MC nylon roller (conductive) (b) PEEK (polyetheretherketone resin) wrapped with aluminum foil ) Mounting pins and extrusion pins (conductive) and carbon-filled MC nylon rollers (conductive) (c) PEEK (polyether ether ketone resin) mounting pins and extrusion pins (insulating) and surface (D) A PEEK (polyetheretherketone resin) mounting pin and an extrusion pin (conductive) and a PVC tape affixed with a PVC tape (aluminum foil) While measuring the lifting speed with a laser displacement meter In a state in which the tray is placed on the roller, the ejector pins to lift between the bars, lifting the glass substrate. At this time, the glass substrate is separated from the protruding pin when it is on the mounting pin, and is separated from the mounting pin when it is on the protruding pin. That is, contact and peeling with each pin are repeated. And the charging potential (V) of the upper surface and lower surface of the glass substrate mounted in each tray was measured. The measurement was started after the glass substrate was charged to + (plus) or minus (−) by 1 kV or more. Moreover, the raising / lowering speed of the protrusion pin was 1.0 m / min without acceleration / deceleration.

As a result, in any condition, even if the elevation was repeated, there was almost no change in the charging potential, and a phenomenon that appeared to be peeled off could not be recognized. This is presumably because the contact area between the glass substrate and the mounting pin is very small. Thereby, it has confirmed that there was no malfunction by mounting and taking out a glass substrate on a tray.
[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.
(A)
In the transport system 100 of the above-described embodiment, the example in which the tray 1 that transports the insulating glass substrate W includes the crosspieces 4 as illustrated in FIGS. 4 and 5 has been described. However, the present invention is not limited to this.

For example, the part on which the glass substrate W is placed may be formed of a conductive flat plate.
(B)
In the conveyance system 100 of the above-described embodiment, an example in which the entire roller 25 is formed of a conductive material has been described. However, the present invention is not limited to this.
For example, as shown in FIG. 17, the contact part 25a which contacts the tray 1 among the rollers 25 may be formed of a conductive material. In this case, if the contact part 25a is appropriately set and grounded somewhere, the same effect as that of the transport system 100 according to the above embodiment can be obtained.
Further, all the rollers need not be conductive, and may be partially attached within a range where a predetermined effect can be obtained.

(C)
In the conveyance system 100 of the above-described embodiment, the roller 25 has been described by taking an example in which the roller 25 is formed of carbon-containing MC nylon. However, the present invention is not limited to this.
For example, you may form with resin, such as ultra high molecular weight polyethylene and polyetherimide containing a conductive material. Moreover, you may form a roller with an electroconductive metal.
In addition, in the present Example, although the experimental data by MC nylon containing carbon was shown, it confirmed that the same effect was acquired also in UPE containing carbon.
(D)
In the conveyance system 100 according to the above-described embodiment, the roller 25 is described by taking an example in which the roller 25 is formed of MC nylon in which conductivity is ensured by containing 1 to 50 wt% of carbon black. However, the present invention is not limited to this.

For example, you may make MC nylon contain 1-50 wt% carbon fiber. Moreover, you may contain a 1-30 wt% carbon nanotube and carbon nanofiber. Also in this case, the same effect as that of the transport system 100 according to the above embodiment can be obtained.
(E)
In the transport system 100 of the above embodiment, the entire tray 1 has been described by taking an example in which the tray 1 is formed from a conductive aluminum extrusion member. However, the present invention is not limited to this.
For example, only the outer flange 11 that is a contact portion with the roller 25 may be formed of a conductive material.

Also, as shown in FIG. 9, since the same effect can be obtained with a tray made of SUS, the same effect can be obtained even if other conductive metal or conductive surface treatment is applied. Obtainable.
(F)
In the transport system 100 of the above embodiment, the glass substrate W has been described as an example of the work that is placed on the tray and transported. However, the present invention is not limited to this.
For example, even in the case of a plate-like work used for an electronic display (liquid crystal display, plasma display, etc.), a resin plate used for an organic EL display or illumination, etc., the same effect as that of the transport system 100 according to the above embodiment is obtained. Obtainable.
(G)
In the transport system 100 of the above embodiment, the example in which the mounting pins 4a formed on the crosspiece 4 are formed has been described. However, the present invention is not limited to this.

  For example, the transport speed of the tray 1 on the transport conveyor 20 may be controlled so that relative movement between the tray 1 and the glass substrate W, that is, slippage does not occur. Also in this case, it is possible to suppress charging caused by friction or separation generated between the tray 1 and the glass substrate W. As a result, it is possible to enhance the effect of suppressing charging when an insulating workpiece is conveyed.

1 is an external view of a transport system according to an embodiment of the present invention. The cross section of the conveyance system concerning one embodiment of the present invention. The expanded sectional view of the roller periphery included in FIG. 1 and FIG. The external view of the tray for conveyance conveyed by the conveyance system of FIG. The top view of the tray for conveyance conveyed by the conveyance system of FIG. Measurement result of charging potential when a glass substrate is transported by a conventional transport method. The graph which showed the speed curve (no acceleration / deceleration) at the time of measuring of FIG. The graph which showed the speed curve (with acceleration / deceleration) at the time of measuring of FIG. Measurement results of charging potential when various types of transport media are transported using the conventional transport method. (A) is the graph which showed the speed curve in the SUS tray at the time of measuring of FIG. (B) is the graph which showed the speed curve in the aluminum tray at the time of measuring of FIG. Measurement result of charging potential when measuring with different materials in tray and roller. Measurement results of charging potential when a glass substrate is placed on an aluminum tray and transported. The graph which showed the speed curve (15 m / min * no acceleration / deceleration) at the time of measuring of FIG. The graph which showed the speed curve (30 m / min * no acceleration / deceleration) at the time of measuring of FIG. The graph which showed the speed curve (45 m / min * with acceleration / deceleration) at the time of measuring of FIG. The graph which showed the speed curve (45 m / min * no acceleration / deceleration) at the time of measuring of FIG. The expanded sectional view of the roller periphery in other embodiment of this invention.

Explanation of symbols

1 Transport tray (tray)
2 Outer frame 2a Frame member 4 Crosspiece 4a Mounting pin 11 Outer flange (contact part)
12 Inner flange 13 Inclined part 20 Conveyor 21 Support frame 21a Main body 21b Support leg 25 Roller (contact part)
25a Contact part 26 Shaft 100 Conveyance system

Claims (5)

A transfer system for transferring an insulating work,
A tray on which the workpiece is placed;
A plurality of rollers arranged side by side in the transport direction for transporting the tray,
In the roller and the tray, at least the mutual contact portion has conductivity,
The conveyance system, wherein the contact portion is grounded. The tray is formed of a conductive material,
The transport system according to claim 1. The roller is formed of a resin containing a predetermined amount of conductive material,
The transport system according to claim 1 or 2. The roller contains 1 to 50 wt% of the conductive material,
The transport system according to claim 3. The roller contains 1-30 wt% of the conductive material,
The transport system according to claim 4.

Images