Fully automatic vacuum lifter

Abstract

To provide a fully automatic vacuum lifter capable of sucking and holding even a workpiece having a slightly inclined surface without reducing suction force and capable of sucking and removing water or the like adhering to the workpiece surface. [Solution] A fully automatic vacuum lifter is equipped with a vacuum generating device, a pressure sensor that detects the pressure inside the base body, a control circuit, a battery, a power switch, and further comprises a base body equipped with a handle operating unit, a suction pad of uniform thickness that comes into close contact with the workpiece, an elastic holder that supports the suction pad so that it can be displaced up and down relative to the base body, and a stop plate that is provided on the base body side of the elastic holder and prevents contact between the suction pad and the base body during suction.

Description

[Technical field]

[0001] The present invention relates to an improvement of a vacuum suction device that suctions a workpiece by using a suction force generated by negative pressure. [Background technology]

[0002] Conventionally, vacuum suction devices incorporating a vacuum pump and the like have been developed and commercialized as vacuum lifters for suctioning and transporting sheet-like or plate-like workpieces.

[0003] These are generally battery-powered and operated by turning a power switch on and off. Patent document 1 also describes a vacuum suction device that includes a body having a port through which negative pressure fluid is supplied, a pad having a flat suction surface made of a porous material, and a holder that holds the pad displaceably relative to the body. Here, the pad has a body portion and a thin lip portion formed on the periphery of the body portion, and the retainer is disposed between the lip portion of the pad and the body.

[0004] According to the above-described vacuum suction device, even if the workpiece is inclined with respect to the suction surface of the pad, the suction surface of the pad can be brought into contact with the workpiece. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5756956 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the pad of the vacuum suction device, the lip portion functions as a sealing portion, so that the lip portion is crushed when the pad is press-molded, forming a step between the main body portion and the lip portion. Such a pad is easily deformed near the step, and there is a risk that the suction surface will not be able to maintain a flat shape.

[0007] In addition, the pad of the vacuum suction device has a certain space between the holding plate attached to the body and the pad to allow the pad to tilt, so that when a high negative pressure is applied, the pad may deform in a tilted state relative to the holding plate, and the suction surface may not be able to maintain a flat shape. Also, when a sudden negative pressure is applied, the pad may be sucked into the body, causing deformation or damage. [Means for solving the problem]

[0008] The present invention has been proposed to achieve the above-mentioned objective, and is a fully automatic vacuum lifter which comprises a vacuum generating device, a pressure sensor which detects the pressure inside the base body, a control circuit, a battery, a power switch, and further comprises a base body equipped with a handle operating unit, a suction pad of uniform thickness which comes into close contact with the workpiece, an elastic holder which supports the suction pad so that it can be displaced up and down relative to the base body, and a stopper plate which is provided on the base body side of the elastic holder and prevents contact between the suction pad and the base body during suction. Effect of the Invention

[0009] According to the present invention, the control circuit, after detecting the power switch being turned on, monitors the pressure sensor to drive the vacuum generator, and when the inside of the base body reaches a predetermined vacuum level, stops the operation of the vacuum generator, and when air has entered the base body and the vacuum level falls below the predetermined level, controls the operation of the vacuum generator to start, and turns off the power switch when the suction operation is completed. Therefore, the suction operation can be used fully automatically and safely. In addition, since it is equipped with an adsorption pad of uniform thickness that comes into close contact with the workpiece, and an elastic holder that supports the adsorption pad so that it can be displaced up and down relative to the base body, even if the workpiece is slightly inclined, the inclination is absorbed by the elastic force of the elastic holder, and the lifter can be held in a vertical position during operation. In addition, the inside of this elastic holder is equipped with a stopper plate that prevents contact between the suction pad and the base body during suction, thereby stably maintaining the suction force during suction operation and preventing deformation of the suction pad. Even if a high negative pressure is suddenly applied, there is no risk of the suction pad being sucked into the passage of the base body and deforming or damaging the suction pad. Furthermore, in the case where the suction pad is provided with a water suction hole and the main body cover is provided with a drainage hole, even if water or other liquid remains on the surface of the workpiece, the liquid can be sucked up and removed by activating the vacuum generating device. Furthermore, if the suction pad is made of soft rubber or silicone, any dust, powder, or dirt on the surface of the workpiece can be sucked away and removed, allowing the workpiece to be lifted safely. [Brief description of the drawings]

[0010] [Figure 1] 1 is an external perspective view showing one embodiment of a fully automatic vacuum lifter according to the present invention; [Diagram 2] FIG. 2 is an exploded perspective view showing the structure of the main part. [Diagram 3] FIG. 2 is a vertical cross-sectional view of the main part when not being attracted to the substrate; [Figure 4] FIG. 2 is a vertical cross-sectional structural view of a main part when a flat workpiece is being sucked. [Diagram 5] FIG. 2 is a vertical cross-sectional structural view of a main part when a workpiece having an inclined surface is being sucked. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] FIG. 1 shows the appearance of the fully automatic vacuum lifter of the present invention. The vacuum lifter A has a cover 10, and a grip handle 11 is fixed to the upper surface of the cover 10 by a bolt 14. A power switch 12 and a display unit 13 are provided at one end of the grip handle 11. Reference numeral 16 denotes a drain hole for when water is sucked in. When liquid such as water adheres to the surface of the workpiece, the adhering liquid can be sucked in by the vacuum lifter 4 and drained to the outside. Reference numeral 41 denotes a protrusion for allowing air to flow into the suction pad 4 in order to detach the suction pad 4 from the workpiece at the end of the suction operation. A vacuum generating device such as a vacuum pump, a control circuit, a pressure sensor, a battery, etc. are housed in appropriate locations within the grip handle 11 or cover, and the pressure sensor detects the pressure within the main body base 2, none of which are shown in the figure.

[0012] 2 and 3 show the main parts housed within the cover 10. As shown in FIG. 2, the main part is composed of a main body base 2, an elastic holder 3, a suction pad 4, and a stopper plate 5, which are assembled together as main parts. Here, the main body base 2 is made of a metal material such as an aluminum alloy, and has a through hole 21 running vertically through the center, with bolt holes 22 provided around the periphery. The grip handle 11 is fixed to the cover 10 by threading a bolt 14 through the bolt hole 22 through the cover 10. A through hole 21 formed in the center of the main body base 2 is connected to a vacuum generating device (not shown).

[0013] Numeral 3 denotes an elastic holder, which is formed in a ring shape and is fixed to the inner peripheral edge of the bottom of the main body base 2 and to the peripheral edge of the upper surface of the suction pad 4. It is made of a porous rubber sponge body made by foaming a material such as rubber to which conductive fillers such as carbon and metals have been added. What is desired is a material that is not breathable, has many closed cells inside, and is durable enough that its cushioning properties and breathability are not lost over a long period of time. The elastic holder 3 has a notched groove 31 formed around its periphery, which forms a first flange portion 31a and a second flange portion 31b. The first flange portion 31a is fitted and fixed to the bottom inner surface of the main body base 2, and the second flange portion 31b is fixed to the peripheral edge of the upper surface of the suction pad 4. In this case, if the workpiece W is attached using conductive double-sided tape or the like, the static electricity generated when the workpiece W is sucked and held can be released to the outside.

[0014] The suction pad 4 is formed into a disk shape to match the shape of the main body base 2, and has a uniform thickness without any steps. The suction pad 4 is made of a material containing resin fibers and conductive filler, such as rubber or silicone, depending on the properties of the workpiece, and the flat lower surface forms an adsorption surface that can come into close contact with a sheet-like or plate-like workpiece. If such an adsorption pad 4 is constructed with a material that has no air permeability at its outer periphery and a material that has air permeability at its middle portion excluding the outer periphery, the adhesion to the workpiece will be further improved. Reference numeral 42 denotes a water absorption hole formed on the bottom surface of the suction pad 4, which is plugged by a bottom cap (not shown) having a shape that does not form a convex portion on the bottom surface of the suction pad during normal suction operation. In the present invention, when necessary, the plug is removed and water or liquid is removed by suction, and the sucked water or liquid is discharged through the drain hole 16 in the cover 10 (see FIG. 1).

[0015] The stop plate 5 is made of a highly rigid metal material such as stainless steel and is formed in a disk shape. The stopper plate 5 has a first hole 51 at its center which is aligned with the negative pressure supply passage 21 of the base body 2, and a plurality of arc-shaped second holes 52 are formed around the first hole 51. As shown in Figure 3, the stopper plate 5 is fixed to the underside of the main body base 2 so as to be positioned inside the opening of the elastic holder 3, and faces the upper surface of the suction pad 4 with a specified gap 6 between them. Such a stopper plate 5 functions as a stopper for the suction pad during the suction operation. In other words, this stop plate 5 prevents the suction pad 4 from coming into contact with the main body base 2 during the suction operation (in the illustrated example, contact with the through hole 21 formed in the center), and fixes and limits the position of the upward displacement of the suction pad 4, thereby preventing deformation or damage caused by excessive suction of the suction pad 4 into the base main body 2. The joint between the elastic holder 3 and the main body base 2 and the joint between the elastic holder 3 and the suction pad 4 are sealed to prevent vacuum leakage.

[0016] Next, an operation of sucking and holding a plate-like workpiece W such as a glass substrate will be described with reference to FIGS. When the vacuum suction device is activated, the central passage 21 of the main body base 2 becomes negative pressure (vacuum pressure), and the negative pressure acts on the upper surface of the suction pad 4 through the first hole portion 51 and the second hole portion 52 of the stopper plate 5, and also acts on the workpiece W in contact with the lower surface of the suction pad 4. Thus, the pressure difference between the negative pressure acting on the upper surface of the workpiece W and the atmospheric pressure acting on the lower surface of the workpiece W increases rapidly. As a result, the workpiece W pushes up the suction pad 4, and the suction pad 4 displaces upward while compressing the elastic holder 3. When the suction pad 4 abuts against the stopper plate 5, the upward displacement of the suction pad 4 is restricted, and the workpiece W is stably adsorbed and held by the suction pad 4 in this state. Furthermore, the impact caused when the workpiece W is lifted is absorbed by the elastic holder 3 undergoing compressive deformation.

[0017] FIG. 4 shows the longitudinal cross-sectional structure of the essential parts when a workpiece that is not inclined and is flat is used. When the upper surface of the highly rigid workpiece W has a relatively precisely flat surface, the suction pad 4 shown in FIG. 3 is displaced upward until the gap 6 disappears and is maintained in that state. On the other hand, when the workpiece W is inclined, the workpiece W is adsorbed and held in the state shown in Fig. 5. That is, in this case, one of the elastic supports 3 contracts in response to the inclination of the workpiece W, and the gap 6 changes accordingly, so that the base body 2 becomes inclined, but the suction pad 4 can lift the workpiece W vertically and maintain close contact with the workpiece W. [Explanation of symbols]

[0018] A Fully automatic vacuum lifter 10 Main unit cover 11 Grab Handle 12 Power Switch 16 Drain hole 2 Base body 3 Elastic holder 4 Suction pads 5 Stop plate

Claims

1. It is equipped with a vacuum generator, a pressure sensor that detects the pressure inside the base body, a control circuit, a battery, and a power switch. Furthermore, the fully automatic vacuum lifter is provided with a base body equipped with a handle operating unit, an suction pad of uniform thickness that comes into close contact with the workpiece, an elastic holder that supports the suction pad so that it can be displaced up and down relative to the base body, and a stopper plate that is provided on the base body side of the elastic holder and prevents contact between the suction pad and the base body during suction.

2. In claim 1, After detecting an ON operation of the power switch, the control circuit drives the vacuum generating device and maintains the suction of air inside the base body by monitoring the pressure sensor, while when it detects an OFF operation, it stops driving the vacuum generating device. This is a fully automatic vacuum lifter.

3. In claim 1 or 2, The suction pad is provided with a water suction hole.

4. In claim 1 or 2, A fully automatic vacuum lifter, in which the suction pad is made of a soft rubber or silicone pad.

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