JP4922495B2 - Transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transfer device used in a continuous heat treatment apparatus such as a furnace. In particular, the present invention relates to a transfer apparatus for a processing apparatus such as a furnace used in a clean room or the like for processing a plate-like workpiece such as a semiconductor substrate, a glass substrate such as an LCD panel or a plasma display panel, or a printed wiring board.
[0002]
In the present specification, front, rear, left, and right refer to the moving direction of the workpiece.
[0003]
[Prior art]
A transfer device for a processing apparatus such as a furnace used in a clean room or the like is required to generate less dust. There is a walking beam type conveying apparatus as one of the conveying apparatuses that satisfy such requirements.
[0004]
The walking beam type conveying apparatus includes a pair of moving beams provided in the left-right direction and extending in the front-rear direction, and a pair of fixed beams arranged in the left-right distance between the moving beams. In this way, the workpiece is transported.
[0005]
First, the moving beam at a position lower than the fixed beam moves upward to lift the object to be processed at the placement position on the fixed beam. Next, the moving beam moves forward until the lifted workpiece reaches the next placement position. Then, the moving beam moves downward and the object to be processed is placed on the next placement position on the fixed beam. After this, the moving beam moves backward.
[0006]
The above-described series of operations are repeated, and the workpiece is sequentially transferred onto the fixed beam and transferred to the front mounting position.
[0007]
[Problems to be solved by the invention]
In the above-described conventional reaction apparatus, the object to be processed in the clean room is a semiconductor substrate or a glass substrate and may be damaged during transportation. Therefore, the speed at which the object to be processed is moved upward from the mounting portion. In addition, there is a certain limitation on the speed at which the workpiece is moved downward and placed on the placement unit. That is, the speed at which the workpiece is moved up and down cannot be increased to the extent that the workpiece may be damaged. For this reason, there is a problem that it is difficult to increase the conveyance speed as a whole. By the way, since the conveyance speed may affect the temperature distribution of the object to be processed, it may be difficult to make the temperature distribution of the object to be processed favorable if the conveyance speed cannot be increased.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, and to provide a transfer device that can increase the transfer speed of the object to be processed as compared with the conventional apparatus and can make the temperature distribution of the object to be processed preferable. The purpose is to provide.
[0009]
[Means for Solving the Problems and Effects of the Invention]
In order to solve the above problems, the transport device of the present invention is
Position detecting means for detecting the vertical position of the beam in a walking beam type conveying apparatus that places a workpiece to be lifted from the workpiece placing portion and lowered to the workpiece placing portion with a pair of beams that move up and down at least And a control means for controlling the vertical movement speed of the beam based on the vertical position of the beam detected by the position detection means, and when the beam lifts the workpiece from the placement portion and lowers it to the placement portion. The vertical movement speed of the placing beam is slowed down.
[0010]
According to this apparatus, the speed at which the workpiece is lifted from the placing section and the speed at which the workpiece is lowered on the placing section is slowed down, and the speed when the workpiece is away from the placing section is increased. Thus, compared with the case where the speed of moving the object to be processed is constant, the speed of moving the object to be processed can be increased. Therefore, the setting range of the conveyance speed of the workpiece is widened, and the temperature distribution of the workpiece can be in a preferable state.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a transfer device of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows a continuous furnace (1) equipped with a transfer device (2) for carrying out the transfer device of the present invention, and FIG. 2 shows a position for controlling the vertical movement speed of a moving beam (4) described later. The concept of detection means and control means is shown.
[0013]
Here, the transfer device (2) includes a pair of moving beams (4) spaced apart from each other on the left and right sides, and a pair of fixed beams (5) spaced apart from each other between the moving beams (4). ). The interval between the moving beam (4) and the interval between the fixed beams (5) is smaller than the width of the workpiece (P), and the workpiece (P) can be placed thereon.
[0014]
A front and rear slide plate (7) projecting downward from the beam (4) is attached to a portion of the moving beam (4) projecting backward from the furnace body, and a vertical motion plate (6) is attached to the slide plate (7). ing.
[0015]
The front / rear slide plate (7) is driven back and forth by a motor (not shown) to move back and forth with respect to the vertical movement plate (6), thereby moving the moving beam (4) between the forward movement position and the reverse movement position. On the other hand, the up-and-down moving plate (6) is driven up and down by the motor (M) to move the front and rear slide plate (7) and the moving beam (4) up and down integrally to move the moving beam (4) to the fixed beam (5). It moves between a raised position above and a lowered position below the fixed beam (5). The mechanism for driving the vertical moving plate (6) by the motor (M) and the mechanism for driving the front / rear slide plate (7) by the motor are well known and will not be described in detail.
[0016]
The up-and-down moving plate (6) is provided with a light shielding plate (6a) projecting rearward therefrom. Four light shielding switches (S1), (S2), (S3), and (S4) are provided at intervals in the vertical direction at positions where light is blocked by the vertical movement of the light shielding plate (6a).
[0017]
The shading switch (S1) is for detecting that the moving beam (4) has reached the raised position, and the shading switch (S4) is for detecting that the moving beam (4) has reached the lowered position. Is. Two switches (S2) and (S3) are arranged between the switches (S1) and (S4). Both switches (S2) and (S3) are provided at the following positions. That is, the moving beam (4) lifts the workpiece (P) from the fixed beam (5) and the fixed beam (5) while the light shielding plate (6a) moves between the two switches (S2) and (S3). It is provided at a position where the workpiece (P) is put down.
[0018]
As shown in FIG. 2, the switches (S1), (S2), (S3), and (S4) are connected to a program logic controller (PLC). The motor (M) is driven by an inverter by an inverter (INV) controlled by a program logic controller (PLC). The configuration for controlling the inverter (INV) by the program logic controller (PLC) and the configuration of the light shielding switches (S1), (S2), (S3), and (S4) are well known, and detailed description thereof is omitted.
[0019]
Hereinafter, the operation of the moving beam (4) will be described.
[0020]
The moving beam (4) first takes an initial state in the retracted position and the raised position. The workpiece (P) is placed on the moving beam (4) in this state.
[0021]
The moving beam (4) on which the workpiece (P) is placed advances to the advance position and stops. Next, the moving beam (4) is lowered. When the moving beam (4) descends and the light blocking plate (6a) blocks the light from the switch (S2), the power supplied to the motor (M) by the inverter (I) decreases and the moving beam (4) descends. The speed is slower than before. Furthermore, after the moving beam (4) is lowered and the workpiece (P) is transferred to the fixed beam (5), the motor (5) is used by the inverter (I) when the light shielding plate (6a) blocks the light from the switch (S3). The power supplied to (M) becomes higher, and the moving beam (4) descends faster than before.
[0022]
When the moving beam (4) descends to a lower position below the fixed beam (5), the moving beam (4) retracts to the retracted position.
[0023]
The moving beam (4) retracted to the retracted position rises to the ascending position and takes an initial state. At this time, the workpiece (P) on the fixed beam (5) is transferred to the moving beam (4) and lifted, but the light shielding plate (6a) is moving between the switches (S2) and (S3). The rising speed of the moving beam (4) in the meantime is slower than the rising speed at other times. In the same manner as above, the position of the moving beam (4) is detected by the light shielding switches (S1), (S2), (S3), and (S4), and the electric power supplied from the inverter (I) to the motor (M) based on this position. This is done by changing.
[0024]
The above-mentioned transport device is one in which one beam (4) moves up and down and back and forth, and the other beam (5) is fixed.However, the transport device of the present invention is not limited to this, and both beams alternate. And the object to be processed (P) is conveyed, and one of the beams is moved up and down and the other beam is moved forward and backward to convey the object to be processed (P).
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view of a furnace equipped with a transfer apparatus for carrying out the transfer apparatus of the present invention, and FIG. 1B is a transverse cross-sectional view of a main part of the transfer apparatus.
FIG. 2 is a conceptual diagram of speed control means of the transport apparatus.
[Explanation of symbols]
(1) Furnace
(2) Transfer device
(4) Moving beam
(5) Fixed beam
(I) Control means (inverter)
(P) Workpiece
(S1) (S2) (S3) (S4) Position detection means (shading switch)

Claims (2)

In the walking beam type transfer device that places the workpiece to be lifted from the workpiece placing portion and lowered to the workpiece placing portion with a pair of beams that move at least up and down,
A motor for moving the beam up and down , a position detection means for detecting the vertical position of the beam, and a control means for controlling the vertical movement speed of the beam by the motor based on the vertical position of the beam detected by the position detection means. Prepared,
The position detecting means includes first to fourth light shielding switches, the first light shielding switch detects that the beam has reached the ascending position, and the second light shielding switch detects that the beam has reached the descending position, A third shading switch detects that the beam has reached the first speed switching position between the ascending position and the descending position, and the second speed switching position below the first speed switching position between the ascending position and the descending position. The fourth shading switch detects that
The control means raises the beam at a high speed and detects the beam by the fourth shading switch until the fourth shading switch detects the beam after the second shading switch detects the beam in the ascending stroke of the beam. Until the third shading switch detects the beam, the beam is raised at a low speed, and during the beam descending stroke, the beam is raised between the detection of the beam by the first shading switch and the detection of the third shading switch. The motor is controlled so that the beam is lowered at a low speed between the time when the beam is detected by the third light shielding switch and the time when the fourth light shielding switch detects the beam.
Walking beam type transport, where the beam lifts the object to be processed from the mounting part when the beam rises at a low speed, and the beam lowers the object to be processed on the mounting part when the beam descends at a low speed apparatus.   The control means raises the beam at a high speed during the beam rising stroke until the first light blocking switch detects the beam after the third light blocking switch detects the beam, and the beam moves the fourth beam at the beam falling stroke. 2. The walking beam type conveying apparatus according to claim 1, wherein the motor is controlled so that the beam is lowered at a high speed between the detection of the light shielding switch and the detection of the second light shielding switch.

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