JPH10310254A - Stacking method of object to be treated - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain upper surface height after stacking in a specified range by making an allowable height range as a specific range of the maximum variable thickness of an article to be treated and setting boundary height between a position higher by the maximum variable height than its lowest limit height and a position lower by the maximum variable thickness than highest limit height. SOLUTION: An allowable height range HE is made in dimensions of more than two times of the maximum variable thickness Te (=d1+d2), and boundary height Hc is set between a position Ha1 higher by Te than lowest limit height Ha of HE and a position Hb1 lower by Te than highest limit height Hb. A base 1 with no work loaded on it is set so that its upper surface comes to be in a range of more than Ha and not more than the position Hb1, and after a first work W1 is loaded on the upper surface of the base 1, the base 1 is lowered by a distance of a range of more than work minimum thickness Tn and less than a distance Bu between Ha and a setting position Bh of the upper surface of the base 1 added with the work minimum thickness Tn. Consequently, it is possible to efficiently stack objects to be treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of stacking objects to be processed on a base, and more particularly to a method of stacking a plurality of objects to be processed while maintaining the upper surface of the object at a predetermined allowable height. About.

[0002]

2. Description of the Related Art For example, in a manufacturing process of a ceramic electronic component, a flat workpiece (hereinafter, abbreviated as "work" as appropriate) such as a ceramic substrate having a variation in thickness is used. After loading on the base, electrode material etc. are printed and applied on the surface of the work, and then the next work is stacked on it and printed and applied,
This may be repeated one after another, and a step of stacking a large number of works on a base (cassette) may be required. In such a case, it is necessary to set the upper surface of each work to a predetermined height in order to appropriately perform processing such as printing and coating of the electrode material. Therefore, conventionally, a method has been used in which the base is lowered every time a work is loaded, and the upper surface of the work is sequentially set at a predetermined height.

[0003] More specifically, as shown in FIG. 10, beside a base B on which a work W is loaded, a light projecting beam L horizontally passing a predetermined height position where the upper surface of the work W is set.
A positioning device formed by arranging light projecting means La for generating B and light receiving means Lb for receiving light beam LB so as to face each other with work W interposed therebetween is used. When the workpieces W are stacked using this positioning device, the workpieces W are stacked on the base by a method described below. First, when the first workpiece W (W1) is stacked on the upper surface of the base B as shown in FIG. The light beam LB is blocked by the work W (W1), and the light receiving means Lb is
B is no longer received. Therefore, as shown in FIG. 10B, the base B and the base B are moved by the actuator (not shown) until the light receiving means Lb receives the light beam LB.
The work W (W1) loaded on the upper part is lowered, and the work W
(W1) is set so that the upper surface thereof has a predetermined height.
Then, on the upper surface of the work W (W1), FIG.
As shown in, when the next work W (W2) is loaded,
Similarly to the case where the first work W (W1) is loaded, the light beam LB is blocked by the work W (W2), and the light receiving means Lb
Stops receiving the light beam LB. Therefore, as shown in FIG.
The base B and the work W loaded on the base B are lowered until the light beam LB is received, and the uppermost work W (W2) is set so that the upper surface thereof has a predetermined height. Then, by repeating this operation, a plurality of works W are stacked on the base B.

However, in the case of the above-mentioned conventional stacking method,
There is a problem that the lowering speed of the base cannot be increased and the processing efficiency is poor. That is, the light emitting means La,
In the base lowering drive control system of the feedback system using the position detecting sensor including the light receiving unit Lb and the actuator, if the base lowering speed is too high, the response speed of the control system cannot follow, and the position of the upper surface of the work W becomes a predetermined position. Greatly deviates from the height of the object, and is out of the range of the allowable height. It is also conceivable to use a high-speed response type with good stopping accuracy for the base descent drive control system to increase the descent speed of the base, but the control system becomes very expensive and the practicality is impaired. There is a point.

The present invention has been made to solve the above-mentioned problem, and it is possible to adjust the upper surface height of the stacked workpieces to a predetermined height without being affected by the response speed of a base lowering drive control system such as a sensor or an actuator. It is an object of the present invention to provide a stacking method capable of efficiently stacking objects to be processed on a base while maintaining the range.

[0006]

In order to achieve the above-mentioned object, the method of stacking objects to be processed according to the present invention provides a method of stacking objects to be processed each time the objects having thickness tolerances of + d1 and -d2 with respect to a reference thickness t are stacked. A method of stacking a plurality of workpieces while lowering the base on which the workpieces are stacked by a predetermined distance, while maintaining the upper surface position of the workpieces to be stacked at a predetermined allowable height, comprising: The height range HE is set to the maximum fluctuation thickness Te (= d1 + d
2) or more, and a position Ha1 above the lower limit height Ha of the allowable height range HE by the maximum change thickness Te, and a position below the upper limit height Hb of the allowable height range HE by the maximum change thickness Te. A base setting step of setting the boundary height Hc between Hb1 and setting the base such that the upper surface of the base on which the workpiece is not loaded is located between the position Hb1 and the lower limit height Ha; b) The object to be processed is loaded on the upper surface of the base set in the base setting step, and the base on which the object to be processed is loaded is set at a minimum height Tn (= t−d2) or more and a lower limit height Ha and An initial workpiece loading step of lowering by a distance equal to or less than a distance obtained by adding the workpiece minimum thickness Tn to the set position of the upper surface of the base; and (c) base lowering in the initial workpiece loading step. After the object to be processed If the height of the surface does not reach the boundary height Hc, after loading the next workpiece on the upper surface of the loaded workpiece, the base is lowered by the workpiece minimum thickness Tn,
If the height of the upper surface of the object to be processed after the lowering of the base in the first processing object loading step exceeds the boundary height Hc, the next object to be processed is loaded on the upper surface of the already-processed object, and then processed. A next workpiece loading step of lowering the base by a distance equal to or greater than the maximum workpiece thickness Tm (= t + d1) and equal to or less than a distance obtained by adding the maximum workpiece thickness Tm to the distance between the boundary height Hc and the position Ha1; , (D) after the next processing object loading step, subsequent processing to load a subsequent processing object on the upper surface of the processing object after the base is lowered in the next processing object loading step in the same manner as the next processing object loading step And a loading step.

Further, a boundary height Hc is set at the center of the allowable height range HE, and in the base setting step, the base is set such that the upper surface thereof is located below the boundary height Hc by the maximum variation thickness Te, In the workpiece loading step, the base is lowered by the workpiece minimum thickness Tn,
In the next workpiece loading step and the subsequent workpiece loading step, the height of the upper surface of the workpiece after the base is lowered is the boundary height H.
When the value exceeds c, the base is lowered by the maximum thickness Tm of the workpiece after the next workpiece is loaded.

Further, a light projecting means for generating a light projecting beam which passes horizontally through the boundary height Hc, and a light receiving means for receiving the light projecting beam are provided so as to be opposed to each other with an object to be processed interposed therebetween.
Each time the base lowering operation is completed in each processing object loading process, the height of the upper surface and the boundary height H of the processing object after the base lowering are determined based on the presence or absence of the detection of the projection beam by the light receiving unit.
It is characterized in that the vertical relationship of c is checked.

[0009]

The operation of the method for stacking objects to be processed according to the present invention will be described below with reference to the drawings. As shown in FIG. 4, the workpiece (work) W is a ceramic substrate having a thickness tolerance of + d1 and −d2 with respect to the reference thickness t, and the maximum variation thickness Te of the workpiece W is (d1 + d2). The processing object maximum thickness (work maximum thickness) Tm is (t + d
1), the minimum thickness of the workpiece (the minimum thickness of the work) Tn is (t
−d2). Further, as shown in FIG. 1A, the allowable height range HE is equal to the maximum fluctuation thickness Te (= d1 + d2).
The position (height) Ha, which is twice as large as the lower limit height Ha of the allowable height range HE by the maximum variation thickness Te.
1 and a position (height) Hb1 below the upper limit height Hb of the allowable height range HE by the maximum variation thickness Te, a boundary height H
c is set. The operation of the present invention when stacking the objects to be processed under such conditions will be described below.

First, in a base setting step, the base 1 on which no work is loaded is set so that the upper surface thereof is in a range not less than the lower limit height Ha and not more than the position Hb1. Then, as shown in FIG. 1 (b), in the first workpiece loading step (first workpiece loading step), the first workpiece W is placed on the upper surface of the base 1.
After loading (W1), as shown in FIG. 1 (c), the distance between the lower limit height Ha and the set position Bh on the upper surface of the base 1 (base) when the work has a minimum thickness Tn (= t−d2) or more. The base 1 is lowered by a distance equal to or less than a distance obtained by adding the minimum thickness Tn of the workpiece to Bu) of the upper surface of the base 1 from the lower limit height. In FIG. 1C, the work W (W1)
The case where the height of the upper surface of the workpiece W does not reach the boundary height Hc is indicated by a dotted line, and the height of the upper surface of the work W (W1) is the boundary height Hc.
The case exceeding c is indicated by a two-dot chain line. At this time, even if the thickness of the work W (W1) is the minimum work thickness Tn, the set position Bh of the upper surface of the base 1 is equal to or higher than the lower limit height Ha, and the lower limit height of the upper surface of the base 1 is set to the minimum work thickness Tn. Since the base 1 does not descend beyond the dimension obtained by adding the protruding dimension Bu, the upper surface of the workpiece W (W1) after the base descends always becomes equal to or greater than the lower limit height Ha.
Conversely, even if the thickness of the workpiece W (W1) is the maximum workpiece thickness Tm, there is a distance equal to or greater than the maximum variation thickness Te between the set position Bh on the upper surface of the base 1 and the upper limit height Hb. Since the base 1 is lowered at least by the minimum work thickness Tn, the rising amount of the upper surface of the work W (W1) after lowering the base is equal to or less than the maximum fluctuation thickness Te. Therefore, in any case, the work W (W1) after the base descends
The upper surface of is always below the upper limit height Hb, as shown in FIG. 1 (c).

In the next workpiece loading step (the next workpiece loading step), the height of the upper surface of the workpiece W after the base is lowered does not reach the boundary height Hc, as shown by a dotted line in FIG. In this case, after the next work W (W2) is loaded on the upper surface of the loaded work W (W1), the base 1 is lowered by the minimum work thickness Tn. At this time, the loaded work W
Between the upper surface of (W1) and the upper limit height Hb, there is a distance equal to or greater than the maximum fluctuation thickness Te, and even when the work W (W1) has the maximum work thickness Tm, the base 1 descends by the minimum work thickness Tn. Work W (W
Since the rise of the upper surface of 1) is suppressed to the maximum fluctuation thickness Te or less, the upper surface of the work W (W1) after the lowering is always less than the upper limit height Hb. Further, as shown by a two-dot chain line in FIG. 1C, when the height of the upper surface of the work W (W1) after the base descends exceeds the boundary height Hc, the loaded work W (W1)
After the next work W (W2) is loaded on the upper surface of 1), the distance is equal to or greater than the maximum work thickness Tm and equal to or less than the distance between the boundary height Hc and the position Ha1 plus the maximum work thickness Tm. Lower the base 1. And the boundary height Hc
When the work W (W2) having the minimum work thickness Tn is stacked on the upper surface of the work W (W1) located as close as possible, the upper surface of the work W (W2) after the base is lowered becomes the lowest position. Since the maximum descending distance of the base 1 is the distance between the boundary height Hc and the position Ha1, the upper surface of the workpiece W (W2) after descending is always equal to or more than the lower limit height Ha. When the work W (W2) having the maximum work thickness Tm is stacked on the upper surface of the work located at the upper limit height Hb, the upper surface of the work W (W2) after the base descends is the highest position. Since the work can be lowered by a distance equal to or more than the maximum work thickness Tm, the upper surface of the work W (W2) after the base is lowered must always be at the upper limit even if the work W having the work maximum thickness Tm is stacked at the upper limit height Hb. Hb or less. That is, as shown in FIG.
The upper surface after the base lowering of (W2) is always within the upper limit allowable height range HE.

After the next work loading step, the subsequent work W is stacked on the upper surface of the work W after the base is lowered in the next work loading step in the same manner as in the next work loading step.
The upper surface of the workpiece W after the lowering is always within the allowable height range HE between the lower limit height Ha and the upper limit height Hb. As described above, the present invention provides a base lowering drive system in which, at the end of the lowering of the base after the preceding work is loaded, the appropriate lowering amount of the base after the next work is loaded is determined in advance in consideration of the thickness tolerance of the base. The base is lowered quickly and accurately without being influenced by the response speed of the base lowering drive control system because the base lowering drive control system of the so-called feedback loop type is not used. be able to.

In the present invention, the allowable height range HE of the upper surface of the work W is set to be at least twice as large as the maximum variation thickness Te (= d1 + d2). However, as shown in FIG. When the work W having the maximum work thickness Tm is stacked on the work W whose upper surface is located at the boundary height Hc and the base is lowered by the work minimum thickness Tn, the upper surface of the work W after the lowering is obtained. Is located above the boundary height Hc by the maximum variation thickness Te, and the work W whose upper surface is located at the boundary height Hc is assumed.
When the work W having the minimum work thickness Tn is loaded on the base material and the base is lowered by the maximum work thickness Tm, the upper surface of the work W after the base is lowered is positioned below the boundary height Hc by the maximum change thickness Te. And as a result,
This is because it is inevitable that the set position of the upper surface of the work fluctuates up to twice the maximum fluctuation thickness Te. This means that the boundary height Hc is a position (height) Ha1 above the lower limit height Ha by the maximum variation thickness Te and a position below the maximum variation thickness Te from the upper limit height Hb of the allowable height range. This is also the reason that the height is set between Hb1.

In the initial work loading step, the boundary height Hc is set at the center of the allowable height range HE, and in the base setting step, the upper surface of the base is lowered from the boundary height Hc by the maximum variation thickness Te. In the first work loading step, the base is lowered by the minimum work thickness Tn, and in the next work loading step and the subsequent work loading step (subsequent work loading step), the workpiece after the base is lowered When the height of the upper surface exceeds the boundary height Hc, after the next object to be processed (work) is loaded, the base is lowered by the maximum work thickness Tm. Below the height of the upper surface of the base set in the base setting step, or exceeding the height above the boundary height Hc by the maximum variation thickness Te. It can be reliably prevented. As a result, the upper surface of the work after the lowering of the base is moved to the maximum fluctuation thickness T.
e, it is possible to always maintain the height within a range of twice as high as the height e, and it is possible to provide a simple descent drive control mode in which the base descent distance is only two types, thereby facilitating control and improving reliability. Will be possible.

As shown in FIG. 3, a light projecting means La for generating a light projecting beam LB running horizontally at a position of a boundary height Hc and a light receiving means Lb for receiving the light projecting beam LB include a work W. Each time the base lowering operation is completed in each work loading process, the light receiving unit Lb detects the light projection beam LB from the light projecting unit La and determines whether the processing after the base lowering is completed. When the vertical relationship between the height of the upper surface of the object and the boundary height Hc is checked, when the base lowering operation is completed, the position of the upper surface of the work W after the base lowering is determined, and as shown by a solid line in FIG. The light beam LB is not blocked by W
b, it is determined that the height of the upper surface of the work W has not reached the boundary height Hc, and as shown by the dashed line in FIG. If not detected by the means Lb, it is determined that the height of the upper surface of the work W exceeds the boundary height Hc. Therefore, in this case, it is possible to easily check the vertical relationship between the height of the upper surface of the workpiece W after the base is lowered and the boundary height Hc only by installing the position detection sensor of the ordinary light emitting / receiving means.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, features of the present invention will be described in more detail by showing embodiments of the present invention. FIG. 5 shows a stack used for carrying out a method of stacking an object to be processed (in this embodiment, a ceramic substrate (however, the type of the object to be processed is not limited to this)) according to an embodiment of the present invention. It is the schematic which shows the principal part structure of a device.

The loading device used in this embodiment includes a work W on the side of a base 1 on which a workpiece W is loaded.
Light projecting means La and light projecting means L installed to face each other with the
A light receiving means Lb for receiving the light beam LB emitted from a, and an actuator 2 for raising and lowering the base 1 are provided.
In addition, as the actuator 2, a motor driven type having a normal configuration is used. Also, the work W is shown in FIG.
As shown in the figure, the thickness tolerance of the work W with respect to the reference thickness t is + d1 and −d2, the maximum fluctuation thickness Te of the work W is (d1 + d2), and the maximum work thickness Tm is (t +
d1) A ceramic substrate having a minimum work thickness Tn of (t−d2).

In this embodiment, as shown in FIG. 6, the allowable height range HE of the uppermost position of the stacked workpieces W is such that the lower limit height Ha and the upper limit height Hb are equal to the maximum variation thickness Te. Doubled. Also, the allowable height range H
A boundary height Hc is set at the center of E, and an upper allowable height range E1 (= Te) above the boundary height Hc and a lower allowable height range E2 below the boundary height Hc (E2 ( = Te) are equal (HE = E1 + E2). The light projecting means La and the light receiving means Lb are arranged so that the light projecting beam LB from the light projecting means La passes horizontally through the position of the boundary height Hc and enters the light receiving means Lb, ie, the light projecting beam Lb. LB
Are arranged such that the optical axis of the light emitting device is located at the boundary height Hc.

Further, as shown in FIG. 7A, the base 1 is set so that the upper surface on which no work is loaded is positioned at the lower limit height Ha of the allowable height range HE. After the workpiece W is loaded, the actuator 2
Thereby, the base 1 can be lowered by the minimum work thickness Tn (FIG. 4). Thereafter, when the height of the upper surface of the work W after the base lowering does not reach the boundary height Hc, the next work W is placed on the upper surface of the loaded work W.
After the base is lowered, the base 1 is lowered by the minimum work thickness Tn. If the height of the upper surface of the work W after the base lowers exceeds the boundary height Hc, the base W is mounted after the next work W is mounted. The actuator 2 operates so as to lower 1 by the maximum work thickness Tm.

The vertical relationship between the height of the upper surface of the workpiece W and the boundary height Hc after the lowering of the base is determined by detecting the light beam LB from the light emitting means La by the light receiving means Lb every time the base lowering operation is completed. Is checked based on the presence or absence of Then, when the base lowering operation is completed, the position of the upper surface of the work W after the base lowering is determined. If the height of the upper surface of the work W does not reach the boundary height Hc, the light beam LB is blocked by the work W. If the height of the upper surface of the work W exceeds the boundary height Hc, the light beam LB is blocked by the work W and the light beam Lb is detected.
It is not detected because it does not enter. That is, if the light projecting beam LB is detected by the light receiving means Lb, the base 1 is lowered by the minimum work thickness Tn after the next work W is loaded, and the light projecting beam LB is not detected by the light receiving means Lb. After the next work W is loaded, the base 1 is configured to descend by the work maximum thickness Tm.

Next, a description will be given of the operation when the work is stacked by the loading device having the above-described configuration. Base setting step As shown in FIG. 7A, the upper surface of the base 1 has a lower limit height Ha.
Set the base 1 so that it comes to the position. Initial Work Loading Step Subsequently, as shown in FIG. 7B, the first (first stage) work W (W1) is loaded on the upper surface of the base 1. Work W (W
As shown in FIG. 7 (c), the base 1 loaded with 1) is lowered by the minimum work thickness Tn. At this time, the work W
If (W1) has the minimum work thickness Tn, the position of the upper surface of the lowered work W (W1) is the position of the lower limit height Ha. The position of the upper surface of (W1) is the boundary height Hc.
Therefore, after the base is lowered, the position of the upper surface of the work W (W1) does not deviate from the allowable height range HE.

Next Work Loading Step After the next (second stage) work W (W2) is loaded on the upper surface of the loaded work W (W1), as shown in FIG.
The base is lowered by the minimum work thickness Tn. As described above, since the upper surface of the first-stage work W (W1) did not exceed the boundary height Hc, the position of the upper surface of the second-stage work W (W2) after the base was lowered is determined by the boundary height Hc. Although it does, it does not exceed the upper limit height Hb. Further, as described above, since the upper surface of the first stage work W (W1) is equal to or greater than the lower limit height Ha, the position of the upper surface of the second stage work W (W2) after lowering the base is also lower limit height. It does not fall below Ha. Therefore, after the base is lowered, the position of the upper surface of the second stage work W (W2) does not deviate from the allowable height range HE. However, the second stage work W (W
The upper surface of 2) may be above or below the boundary height Hc as shown in FIG. 7D.

Subsequent Work Loading Process For generalization, a case where the work W is the work n in the n-th stage will be described. As shown in FIG. 8A, the upper surface of the work n exceeds the boundary height Hc and the upper allowable height range E1.
If the height of the upper surface of the workpiece n is Hn (= E2 + α + Ha) in the case where the light beam LB is interrupted,
Since the height Hn of the upper surface of the work n exceeds the boundary height Hc, after loading the subsequent work (n + 1), the base 1
As shown in FIG. 8B, the work maximum thickness Tm (=
(t + d1) (FIG. 4). Hereinafter, the height range of the upper surface of the work (n + 1) after the base is lowered will be considered.

The upper surface of the work (n + 1) after the base descends is the lowest when the thickness of the work (n + 1) is the minimum work thickness Tn. In this case, the work (n +)
The position of the upper surface of 1) is obtained by subtracting the maximum work thickness Tm (FIG. 4) from the product of the height Hn of the upper surface of the work n and the minimum work thickness Tn of the work (n + 1) (FIG. 4). ), That is, Hn + Tn−Tm = Hn + (t−d
2)-(t + d1) = Hn- (d1 + d2) = Hn-T
e = Hn-E2. On the other hand, from Hn = Ha + E2 + α, Hn−E2 = Ha + α, and does not fall below the lower limit height Ha. Work (n + 1) after base descent
Is the highest when the thickness of the work (n + 1) is the maximum work thickness Tm. In this case, the position of the upper surface of the work (n + 1) is determined by the height Hn of the upper surface of the work n. The position (height) obtained by subtracting the maximum work thickness Tm from the sum of the maximum work thickness Tm of the work (n + 1),
That is, Hn + Tm-Tm = Hn, the original height is maintained, and does not exceed the upper limit height Hb. Therefore, even when the upper surface of the work n exceeds the boundary height Hc, the upper surface of the next work (n + 1) after the base is lowered must be within the allowable height range as shown by hatching in FIG. 8B. H
Maintained within E.

Further, as shown in FIG.
Is below the boundary height Hc, and the lower allowable height range E2
If the height of the upper surface of the work n is Hn (= Hb-E1-β) in the case where the projection beam LB is not interrupted, the upper surface of the work n is lower than the boundary height Hc. After loading the following work (n + 1), the base 1
As shown in FIG. 9B, the minimum work thickness Tn (FIG. 4)
Just descend. Hereinafter, the work (n + 1) after the base descends
Consider the height range of the upper surface of.

The position of the upper surface of the work (n + 1) after the base descends is the lowest when the work (n + 1) has the minimum work thickness Tn (= t−d2). The position of the upper surface is a position (height) obtained by subtracting the minimum work thickness Tn from the sum of the height Hn of the upper surface of the work n and the minimum work thickness Tn of the work (n + 1), that is, Hn + Tn−Tn = Hn. The original height is maintained and does not fall below the lower limit height Ha. The position of the upper surface of the work (n + 1) after the base descends is the highest when the work (n + 1) has the maximum work thickness Tm (FIG. 4). In this case, the position of the upper surface of the work (n + 1) is obtained. Means that the work (n +
The position (height) obtained by subtracting the minimum work thickness Tn (FIG. 4) from the sum of the maximum work thickness Tm of 1), that is, H
n + Tm-Tn = Hn + (d1 + d2) = Hn + Te =
Hn + E1 = Hb-β, and Hn does not exceed the upper limit height Hb. Therefore, even when the upper surface of the work n is lower than the boundary height Hc, the next work (n + 1)
9B is always maintained within the allowable height range HE, as indicated by hatching in FIG. 9B.

After the second stage work W (W2) is loaded and the base 1 is lowered as described in the preceding next work loading step, as shown in FIG. Whether the upper surface is in the upper allowable height range E1 beyond the boundary height Hc or, as shown in FIG. 9A, whether the upper surface of the work n is lower than the boundary height Hc and is in the lower allowable height range E2. It is obvious that the upper surface of the subsequent work W after the third stage after the lowering of the base is always within the allowable height range HE regardless of the number of stacked stages. More specifically,
According to the method of the present invention, the dimensional tolerance +0.05 mm, −
0.05mm ceramic substrate has an allowable height range of 0.2
It has been confirmed that they can be stacked on the upper surface of the base 1 within mm.

As described above, according to the present invention, at the end of the lowering of the base after the preceding work is loaded, a proper amount of lowering of the base after the next work is loaded is determined in advance in consideration of the thickness tolerance of the base. (In other words, the so-called feedback loop-type base lowering drive control method is not used), so that the base can be lowered quickly and accurately without being affected by the response speed of the base lowering drive control system. It is possible to always control the height of the upper surface of the work within an allowable range. Further, since the base descent distance is a simple descent drive control mode having only two types, implementation is easy. Furthermore, the practicality is high in that the vertical relationship between the height of the upper surface of the workpiece W after the base is lowered and the boundary height Hc can be reliably checked only by the position detection sensor including the projecting / receiving means.

In the above embodiment, the allowable height range H
Although the case where E is twice as large as the maximum variation thickness Te has been described, the present invention provides that the allowable height range is 2 times the maximum variation thickness Te.
In the case of more than twice, it is possible to apply without any restrictions. Further, the loading device used to carry out the method of stacking objects to be processed according to the present invention is not limited to the loading device shown in FIG. 5 and used in the above embodiment, but may be a loading device having various other configurations. It is possible. The present invention is not limited to the above-described embodiment in other respects as well. The material and reference thickness of the workpiece (work), the thickness dimension tolerance, the height and the boundary of the upper surface of the workpiece after the base is lowered. Various applications and modifications can be made to the specific configuration of the mechanism for checking the vertical relationship of the height Hc within the scope of the present invention.

[0030]

As described above, according to the method of stacking objects to be processed of the present invention, the present invention considers the thickness tolerance of the base at the end of the lowering of the base after loading the object to be processed in the preceding stage and takes the following into consideration. Since a method of determining an appropriate amount of lowering of the base after the workpiece is loaded is adopted (in other words, a so-called feedback loop type base lowering drive control method is not adopted), the base lowering drive control system The base can be quickly and accurately lowered without being affected by the response speed of the workpiece, and the workpiece can be stacked efficiently while always controlling the height of the workpiece upper surface within an allowable range. .

Further, in the first workpiece loading step, a boundary height Hc is set at the center of the allowable height range HE, and in the base setting step, the upper surface of the base is lowered from the boundary height Hc by the maximum variation thickness Te. In the first workpiece loading step, the base is lowered by the minimum workpiece thickness Tn, and in the next workpiece loading step and the subsequent workpiece loading step, the base is lowered. If the height of the upper surface of the workpiece exceeds the boundary height Hc, the next workpiece is loaded, and then the base is lowered by the maximum workpiece thickness Tm. Is reliably prevented from being lower than the height of the upper surface of the base set in the base setting step, or exceeding the height above the boundary height Hc by the maximum variation thickness Te. It can be. As a result, it is possible to always maintain the upper surface of the object to be processed after the base is lowered within a range of a height twice as large as the maximum variation thickness Te, and to perform simple lowering driving with only two types of base lowering distances. It becomes a control mode, control can be facilitated, and reliability can be improved.

Further, when the vertical relationship between the height of the upper surface of the object to be processed after the base is lowered and the boundary height Hc is checked based on the presence or absence of detection of the light projecting beam from the light projecting means by the light receiving means, The height of the upper surface of the object and the boundary height Hc
It is possible to easily check the hierarchical relationship of
The present invention can be made more effective.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a positional relationship of a work upper surface, a base, and the like when a work is stacked by a method of stacking objects to be processed (work) according to the present invention.

FIG. 2 is a schematic diagram for explaining a limit of an allowable height range in the method of stacking objects to be processed according to the present invention.

FIG. 3 is a schematic diagram showing a check state of a vertical relationship between a height of an upper surface of a work (workpiece) and a boundary height in the method of stacking workpieces according to the present invention.

FIG. 4 is a front view showing workpieces stacked by the method of the present invention.

FIG. 5 is a schematic view illustrating a main configuration of a loading device used in the method of stacking objects to be processed according to the present invention.

FIG. 6 shows a work (object to be processed) in the embodiment of the present invention.
FIG. 4 is a schematic diagram showing an allowable height range of the upper surface of FIG.

FIG. 7 is a partial process diagram showing a situation from a base setting process to a next work loading process in the embodiment of the present invention.

FIG. 8 is a partial process diagram showing a workpiece loading state in a subsequent workpiece loading process in the embodiment of the present invention.

FIG. 9 is a partial process diagram showing another work loading state of the subsequent work loading process in the embodiment of the present invention.

FIG. 10 is an explanatory view showing a conventional method of stacking objects to be processed.

[Explanation of symbols]

1 Base Bh Set position of upper surface of base Bu Projection dimension of upper surface of base from lower limit height Ha1 Position above maximum lower limit height Ha by maximum variation thickness Te Hb1 Position below maximum upper limit height Hb by maximum variation thickness Te d1 , D2 dimensional tolerance of workpiece (work) Ha lower limit height Hb upper limit height Hc boundary height HE allowable height range La light projecting means Lb light receiving means LB light projecting beam t reference thickness Te of work (work) Maximum fluctuation thickness Tm Maximum thickness of workpiece (Work maximum thickness) Tn Minimum thickness of workpiece (Minimum thickness of workpiece) W Workpiece (Work)

Claims (3)

[Claims] 1. A thickness dimension tolerance with respect to a reference thickness t is + d1.
And -d2, by lowering the base by a predetermined distance each time the objects to be processed are stacked on the base, thereby maintaining the upper surface position of the objects to be stacked at a predetermined allowable height. (A) setting the allowable height range HE to the maximum variation thickness Te of the object to be processed.
(= D1 + d2) or more, and a position Ha1 above the lower limit height Ha of the allowable height range HE by the maximum variation thickness Te, and a position Ha1 below the upper limit height Hb of the allowable height range HE by the maximum variation thickness Te. A base setting step of setting a boundary height Hc between the position Hb1 and setting the base such that the upper surface of the base on which the workpiece is not loaded is located between the position Hb1 and the lower limit height Ha. (B) The object to be processed is loaded on the upper surface of the base set in the base setting step, and the base on which the object to be processed is loaded is set to a minimum height Tn (= t−d2) or more and a lower limit height An initial workpiece loading step of lowering by a distance equal to or less than a distance obtained by adding the minimum workpiece thickness Tn to the distance between Ha and the set position of the upper surface of the base; Base descent If the height of the upper surface of the workpiece does not reach the boundary height Hc, the next workpiece is loaded on the upper surface of the loaded workpiece, and then the base is lowered by the minimum thickness Tn of the workpiece. If the height of the upper surface of the workpiece after the base is lowered in the first workpiece loading step exceeds the boundary height Hc, the next workpiece is loaded on the upper face of the loaded workpiece, The next workpiece loading step of lowering the base by a distance equal to or greater than the workpiece maximum thickness Tm (= t + d1) and less than or equal to the distance between the boundary height Hc and the position Ha1 plus the workpiece maximum thickness Tm (D) After the next workpiece loading step, the subsequent workpieces to be loaded on the upper surface of the workpiece after the base of the next workpiece loading step is lowered in the same manner as the next workpiece loading step. A method for stacking objects to be processed, comprising a step of loading the objects to be processed. 2. A boundary height Hc is set at the center of the allowable height range HE, and in a base setting step, the base is set so that its upper surface is located below the boundary height Hc by a maximum variation thickness Te. In the workpiece loading step, the base is lowered by the minimum workpiece thickness Tn, and in the next workpiece loading step and the subsequent workpiece loading step, the height of the upper surface of the workpiece after the base lowers is the boundary height. 2. The method according to claim 1, wherein when the height exceeds Hc, the base is lowered by the maximum thickness Tm of the workpiece after loading the next workpiece. 3. A light projecting means for generating a light projecting beam which passes horizontally through a boundary height Hc and a light receiving means for receiving the light projecting beam are installed so as to face each other with an object to be processed interposed therebetween. Each time the base lowering operation is completed in the object loading process, based on the presence or absence of the detection of the projection beam by the light receiving unit,
3. The method according to claim 1, wherein a vertical relationship between the height of the upper surface of the workpiece after the base is lowered and the boundary height Hc is checked.