JPH10309689A - Conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve conveying accuracy by a simple structure. SOLUTION: A conveying device is provided with a base 20, a linear guide 22 fixed on the base 20, a supporting member 24 for supporting a work piece W and to be straight moving along the linear guide 22, and a block 30 having the approximately same shape as the linear guide 22 approximately symmetrically fixed on the back of the surface on which the linear guide 22 of the base 20 is fixed across the base 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for transferring a plate-like work with high accuracy.

[0002]

2. Description of the Related Art Conventionally, in a transfer apparatus for transferring a plate-shaped work, particularly when the work is stored or taken out of a cassette or the like for storing the work in a stacked state, the work is formed in a plate shape. If the dimensions are quite large, slight tilting or bending when the transfer device supports the work,
A slight inclination due to the installation of the cassette or the like appears as a considerably large value as a deviation between the leading end position of the work and the storage position of the cassette.

This situation will be described with reference to FIG.

In FIG. 7, a transfer device 100 includes a linear guide 104 for moving an arm 102 in the left-right direction in the figure.
, A base 106 that supports the linear guide 104, and a rotary elevating mechanism 108 that rotates the base 106 in a horizontal plane and moves the base 106 up and down. In the transport device 100 configured as described above,
The inclination of the axis of the rotary elevating mechanism 108 is small and the base 106
Even if the amount of inclination of the tip of the workpiece W is small such as δ1, when the size of the work W is large, the amount of inclination of the tip of the arm 102 and further the tip of the workpiece W becomes δ3, which is considerably larger than δ1, and Is large. Further, in addition to such a tilt, the arm 10
2 and the deflection of the work are added to this shift amount, so that the shift amount at the front end of the work W is further increased. Also,
The displacement δ4 due to the inclination of the cassette also increases as the work to be stored becomes larger.

On the other hand, regarding the cassette, it is preferable to stack the work at a pitch as narrow as possible in order to improve the storage efficiency of the work. In this case, the arm 102 of the transfer device 100 needs to enter a narrow space corresponding to each work, and the arm 102
Is very strict.

Considering these facts, in order to store and take out the work in the cassette without error and to improve the storage efficiency of the cassette, extremely strict accuracy is required for the transfer device.

As a method for satisfying such a demand for accuracy, the following method can be considered. (1) The deflection of a work is reduced by improving the method of supporting a plate-like work. (2) The rigidity of the arm for transferring the work is increased, and the deflection of the arm itself is reduced. (3) The method of transferring the work to the cassette is restricted. (4) Normally, the accuracy of a plurality of used cassettes is improved so that the work storage position is kept constant even when the cassette is changed. (5) Improve the transfer accuracy of the transfer device.

[0008]

However, in the above-mentioned method (1), for example, parts which must not come into contact with the workpiece for reasons of maintaining the quality of the product or of the structure of the apparatus. However, there is a problem that some parts cannot be brought into contact with each other, and optimal work support cannot always be performed.

In the method (2), the effect may be obtained by improving the material and shape of the arm. However, it is necessary for the arm having the work to enter and exit the space within the narrow stacking pitch of the cassette. Therefore, there is a limitation on the thickness of the arm, and there is a limit in improving the rigidity of the arm.

In the method (3), a space may be provided at the upper or lower end of the cassette or in the width direction. For example, a space is provided at the upper end of the cassette, and the work is stored from the upper stage of the cassette. Also,
A space is provided at the lower end of the cassette, and the work is discharged from the lower stage of the cassette. With such a method, the demands on the accuracy of the transfer device are reduced. However, if an extra space is provided in the cassette, the storage efficiency is reduced by the dead space of the cassette. In addition, there are restrictions on the method of storing and removing the work in the cassette.

In the method (4), the cost of the cassette is increased, and the cost is increased by the number of cassettes (usually a considerable number).

Further, in the method (5), it is necessary to increase the rigidity and accuracy of the transfer device itself, that is, the device drive system and the structure. In particular, in such a transfer apparatus as described above, since the warpage of the linear guide 104 due to heat appears as a large value, a rigidity-up or cooling structure that can cancel the influence of heat is required. Therefore, there arises a problem that the device becomes considerably large and the cost becomes high.

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a transfer device which has a simple structure and can improve transfer accuracy.

[0014]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, a transfer device according to the present invention includes a base, a linear guide fixed on the base, and support means for supporting a work, and linearly moves along the linear guide. It is characterized by comprising a support means and a block having substantially the same shape as that of the linear guide, which is fixed symmetrically across the base on the back side of the surface of the base on which the linear guide is fixed.

Further, in the transfer device according to the present invention, the block is made of a material having a thermal expansion coefficient equivalent to that of the linear guide.

Further, in the transfer device according to the present invention, the work is a plate-shaped member.

Further, in the transfer device according to the present invention, the work is a glass substrate for a liquid crystal display device.

Further, in the transfer device according to the present invention, the base is made of a material having a lower specific gravity than the linear guide.

Further, in the transfer apparatus according to the present invention, the base is made of a material having a larger coefficient of thermal expansion than the linear guide.

Further, in the transport device according to the present invention, a part of an endless timing belt stretched over at least two pulleys is fixed to the support means, and the support means rotates the timing belt. Is driven straight ahead.

Further, in the transfer apparatus according to the present invention, the pulley is driven to rotate by a motor.

Further, in the transport device according to the present invention, the pulley is covered by a cover.

Further, the transporting device according to the present invention is characterized by further comprising a rotating means for rotating the base in a horizontal plane, and a vertically moving means for vertically moving the base.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing the overall configuration of a transfer apparatus according to one embodiment, FIG. 2 is a side sectional view of the linear motion mechanism of FIG. 1, FIG. 3 is a view of FIG. 2 viewed from below, and FIG. FIG. 5 is a sectional view taken along line AA of FIG. 2, and FIG. 5 is a sectional view taken along line BB of FIG.

In FIG. 1, the transfer device 10 includes an arm 1
A linear motion mechanism 14 for moving the linear motion mechanism 2 in the horizontal direction (arrow R direction) in the figure, and a rotary elevating mechanism for rotating the linear motion mechanism 14 in a horizontal plane (arrow T direction) and moving the linear motion mechanism 14 in the vertical direction (arrow Z direction). And a mechanical unit 16.

The rotary elevating mechanism 16 is composed of, for example, a rotary air cylinder, but is not limited to this, and may be driven by a motor or the like.

The linear motion mechanism 14 includes a base 20 fixed to the upper end of the rotating shaft 18 of the rotary elevating mechanism 16 and a base 2.
The rail 22 includes a linear guide rail 22 fixed on the rail 0, a slider 24 slidably supported by the rail 22, and the arm 12 fixed to the slider 24. As shown in FIG. 2, the slider 24 includes a bearing 26 which is guided and moved by the rail 22 and a support member 28 fixed on the bearing 26 and supporting the arm 12. The arm 12 supports and transports the work W. In this embodiment, the work W is a glass substrate for a liquid crystal display device.

As shown in FIG. 2, on the lower surface of the base 20,
At a position symmetrical to the rail 22 across the base 20, a block 30 of substantially the same shape and the same material as the rail 22 is fixed.

The slider 24 is fixed to a fixing portion 32a of the timing belt 32 by a fixing member 34 as shown in FIGS. 4 and 5, and when the timing belt 32 is driven to rotate, the slider 24 Move in the R direction.

As shown in FIG. 5, timing pulleys 36 and 38 are rotatably supported at both ends of the upper surface of the base 20, and an endless timing belt 32 is wound therearound. The timing pulley 38 is provided with a tension mechanism (not shown), and adjusts the tension of the timing belt 32.

On the other hand, as shown in FIGS.
A timing pulley 40 is rotatably supported at one end of the lower surface of the “0”, and is connected to the timing pulley 36 by a shaft 42.

At the lower center of the base 20, a timing pulley 44 for driving is arranged in a state of being connected to a rotating shaft of a servomotor 46 via a speed reducer 48, and the rotation of the servomotor 46 is controlled by a belt. 50.

As shown in FIG. 3, the timing pulleys 40,
A timing belt 50 is wound around the gap 44, and the tension of the timing belt 50 is adjusted by adjusting the positions of the idlers 52 and 54.

With the above configuration, the arm 12 is connected to the base 2
It operates as follows for 0.

When the servo motor 46 rotates, the speed reducer 4
8, the timing pulley 44 rotates. When the timing pulley 44 rotates, the timing pulley 40 is rotationally driven via the timing belt 50. When the timing pulley 40 rotates, the timing pulley 36 rotates integrally with the timing pulley 40, and the timing pulley 38 also rotates via the timing belt 32. As a result, the slider 24 fixed to the fixed portion 32a of the timing belt 32 moves in the direction of arrow R. Then, the arm 12 and the work W supported by the arm 12 move in the direction of the arrow R.

The base 20 is provided with the rotary elevating mechanism 16.
As a result, the work W is conveyed in three directions of T, Z, and R as a result of this operation and the overall operation of the linear motion mechanism 14 because the work W is moved up and down in the arrow Z direction.

A cover (not shown) having a notch through which the timing belt 32 enters and exits is provided around the timing pulleys 36 and 38, and a cover that covers the timing pulleys 40 and 44 is provided below the base 20. (Not shown), and a grooved ring (not shown) is provided in the portion of the rotary elevating mechanism 16 where the rotating shaft 18 slides. Then, the above-mentioned cover and ring and the rotary elevating mechanism 16
The main body 56 is cleaned by vacuum suction.

In the transfer apparatus as described above, the linear motion mechanism section 14 is the leading end, and the rotary elevating mechanism section 16 also has a layout with peripheral devices of a system configured by incorporating the transfer apparatus. For the above reasons, the linear motion mechanism 1
4 is required to be as light and compact as possible.

Therefore, usually, the base 2 of the linear motion mechanism 14
A material having a low specific gravity, such as aluminum, is selected as the zero material, and the thickness and shape of the base 20 are desired to be made as small as possible from the viewpoint of space, thereby achieving compactness. On the other hand, the rail 22 is usually a standard product of a commercial manufacturer, and the material is limited to iron or stainless steel in terms of hardness, accuracy, and the like.

Further, since the transfer device is required to have the accuracy of movement in the R direction, it is desirable to use a servo control system using a servo motor 46 as a drive system as in this embodiment.

When the above request is made in a normal configuration (a configuration not using the block 30 of this embodiment), the following operations (1) → (2), (1) → (3) are performed. become. (1) Heat is generated by the servo motor 46 and the slide of the rail 22, and the heat is transmitted to the base 20 and the rail 22. (2) Since the base 20 and the rail 22 have different coefficients of thermal expansion,
Warpage occurs due to the bimetal effect (Fig. 6)
reference). (3) Base 2 enough to control thermal expansion of rail 22
When the rigidity of the rail 20 is increased (that is, the thickness of the mounting portion of the base 20 to which the rail 22 is attached is increased to increase the heat dissipation, and at the same time, the rigidity to overcome the bending force of the rail 22 is increased), It is impossible to reduce the weight and size of the 14.

Therefore, as shown in this embodiment, the rail 22
A block 30 of the same material and the same shape as that of the base 2 is provided.
The rail 22 and the block 30 are arranged so as to be symmetrical with respect to 0. As a result, the thermal expansion described in (2) occurs equally above and below the base 20, and as a result, the bending force due to the thermal expansion does not act on the base 20.

As described in (3), the base 20 made of aluminum requires a considerable base thickness to obtain the same rigidity as that of the rail 22, but the block 30 made of the same material as the rail 22 is required. By disposing the rail 22
The warpage of the base 20 due to heat can be prevented only by an increase in the cross-sectional dimension equivalent to that of the above.

The method of the present embodiment does not normally serve as a reinforcing bar for suppressing bending, vibration, and the like of the arm, and is intended only to suppress warping of the base due to heat. . Therefore, in order to play the role of the reinforcing bar, the higher the strength, such as the cross-sectional shape and the material, the higher the effect can be obtained. On the other hand, the block 30 that serves to prevent warping in the present embodiment is only The highest effect can be obtained when the guide rail is made of the same material (thermal expansion coefficient) and shape as the guide rail.

That is, as for the shape of the block 30, if the guide rail is small, the space and the weight are small and a high effect can be obtained. A great effect can be obtained by using the shaft. (Other Embodiments) (1) In the above-described embodiment, the length of the block 30 in the longitudinal direction (R direction) is the same as the length of the rail 22. If it is desired to restrict the movement only when the arm 30 and the work W are most protruded in the R direction, the length of the block 30 in the longitudinal direction can be reduced to half, and the arrangement can be made even if the block 30 is arranged only in the right half in the longitudinal direction. There is. (2) The shape of the block 30 may be any shape as long as the amount of thermal expansion with the rail 22 can be balanced. (3) The rail 22 is connected to the block 3 via the base 20.
It is also possible to mount the base 20 directly (with the base 20 sandwiched by bolts). (4) The driving method in the R direction may be another method such as a wire or a ball screw, without depending on the timing belt. (5) Although the three-axis configuration of T, R, and Z has been described as the transport device, a configuration having two axes or four or more axes may be used including the R axis. (6) The material of the block 30 may be any material as long as it has substantially the same coefficient of thermal expansion as the rail 22.

[0047]

As described above, according to the present invention,
By a simple method of disposing a block having a coefficient of thermal expansion equivalent to that of a rail mounted on the base of the straight shaft of the transfer device below the base, it is possible to eliminate warping of the straight shaft due to heat generation.

The prevention of warpage of the straight-moving shaft due to heat generation according to the present invention has the following effects as compared with the prevention method using other methods. (1) It is lightweight and compact, and can reduce the size of the entire transfer device. (2) Since only blocks are added, there is almost no increase in cost. (3) The structure is simple, and no special control or correction is required.

[0049]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a transport device according to an embodiment.

FIG. 2 is a side sectional view of the linear motion mechanism section of FIG.

FIG. 3 is a view of FIG. 2 as viewed from below.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is a diagram showing a state in which the base is warped due to thermal expansion.

FIG. 7 is a diagram illustrating a configuration of a conventional transport device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Conveying apparatus 12 Arm 14 Linear motion mechanism part 16 Rotating elevating mechanism part 18 Rotating shaft 20 Base 22 Rail 24 Slider 26 Bearing 28 Supporting part 30 Block 32,50 Timing belt 34 Fixing member 36,38,40,44 Timing pulley 42 Shaft 46 Motor 48 Reduction gear 52, 54 Idler 56 Rotary lifting mechanism main body

Claims (10)

[Claims] 1. A base, a linear guide fixed on the base, support means for supporting a work, the support means moving straight along the linear guide, and the linear guide of the base And a block having substantially the same shape as the linear guide, which is fixed symmetrically across the base on the back side of the surface on which the base is fixed. 2. The transfer device according to claim 1, wherein the block is made of a material having a thermal expansion coefficient equivalent to that of the linear guide. 3. The transfer device according to claim 1, wherein the work is a plate-shaped member. 4. The transfer device according to claim 3, wherein the work is a glass substrate for a liquid crystal display device. 5. The transfer device according to claim 1, wherein the base is made of a material having a lower specific gravity than the linear guide. 6. The transfer device according to claim 5, wherein the base is made of a material having a larger thermal expansion coefficient than the linear guide. 7. A part of an endless timing belt wrapped around at least two pulleys is fixed to the support means, and the support means is driven straight by rotation of the timing belt. The transport device according to claim 1, wherein 8. The transfer device according to claim 7, wherein the pulley is driven to rotate by a motor. 9. The transfer device according to claim 7, wherein the pulley is covered by a cover. 10. The transport apparatus according to claim 1, further comprising a rotating unit that rotates the base in a horizontal plane, and a vertical moving unit that moves the base in a vertical direction.