JP2004195570A - Thrust generating noncontact suction means - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To impart thrust to a work sucked in noncontact. <P>SOLUTION: This thrust generating noncontact suction means has a fluid blowout hole 12 opening in a suction surface 11, and is constituted so as to suck the work Wk in noncontact by using negative pressure generated when fluid jetting from the blowout hole 12 flows between the suction surface 11 and a surface Wka of the work Wk. The blowout hole 12 is constituted so as to obliquely extend in the direction orthogonal to the suction surface 11. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention utilizes the fact that a static pressure becomes negative pressure when a fluid flows at a high speed, holds the work in a non-contact manner, and uses a flow of the fluid to apply a thrust to the work. It relates to a contact adsorption means.
[0002]
[Prior art]
As the non-contact adsorption means, there is known a non-contact adsorption means in which a gas outlet opening to an opening is provided on a suction surface and a work near the adsorption surface is adsorbed based on a Bernoulli effect of a gas flow ejected from the outlet. For example, Patent Document 1).
As shown in FIG. 8, the non-contact suction means 6 allows gas ejected from a blowing hole 62 extending in a direction perpendicular to the planar suction face 61 to flow between the suction face 61 and the work Wk at a high speed. , The static pressure P becomes a negative pressure lower than the atmospheric pressure Po, so that the work Wk is sucked.
Further, since the blowout hole 62 extends in a direction orthogonal to the suction surface 61, the gas blown out from the blowout hole 62 flows so as to expand concentrically with respect to the blowout hole 62, and flows on the concentric circle. At each position, the flow has a substantially uniform flow velocity in the radial direction. That is, the gas flows almost uniformly radially around the blowout hole 62.
[0003]
[Patent Document 1]
JP-A-3-43180
[Problems to be solved by the invention]
By the way, in the non-contact suction means 6, since the gas flows almost evenly in a radial manner, the work Wk can be stably sucked and held, and the work Wk hardly moves unless an external force is applied.
However, if a thrust can be applied to the work Wk using such a non-contact suction means, a new use value will be generated.
For this reason, the inventor has continued research and development, and as a result, has developed a thrust generating type non-contact suction means capable of applying a thrust to the work while holding the work in a non-contact manner.
[0005]
The present invention has been made based on the above research and development, and has as its object to provide a thrust generating type non-contact suction means capable of applying a thrust to a work while adsorbing the work in a non-contact manner.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 has an outlet for a fluid which is opened on the suction surface, and the fluid ejected from the outlet flows between the suction surface and the surface of the work. The workpiece is suctioned in a non-contact manner by utilizing a negative pressure generated at the time, and the blowout hole extends obliquely to a direction orthogonal to the suction surface. I have.
[0007]
According to a second aspect of the present invention, in the first aspect of the present invention, the blowout hole extends at an angle of 15 to 60 degrees with respect to a direction perpendicular to the suction surface. .
[0008]
According to a third aspect of the present invention, in the first or second aspect, the blowout hole is formed to have an axial length that is three times or more a diameter.
[0009]
In the invention according to any one of claims 1 to 3 configured as described above, the fluid ejected from the blowout hole flows at a high speed by flowing through the narrow space between the suction surface and the surface of the work, and the static pressure of the fluid is increased. Becomes low pressure according to Bernoulli's law. In this case, since the static pressure becomes a negative pressure lower than the atmospheric pressure, the work can be held by suction.
[0010]
On the other hand, since the ejection holes are formed obliquely to the direction orthogonal to the suction surface, the fluid ejected from the ejection holes has a partial velocity in the direction along the suction surface on the ejection side. Become. For this reason, the fluid ejected from the outlet has theoretically a speed component obtained by synthesizing the component of the speed concentrically spreading from the outlet and the component of the partial speed. Therefore, the flow velocity on the downstream side in the above-mentioned speed-dividing direction becomes relatively high, and the flow velocity on the upstream side in the above-mentioned speed-dividing direction becomes relatively slow with respect to the outlet. Then, the absolute value of the negative pressure indicated by the static pressure increases on the downstream side where the flow velocity is high, and the absolute value of the negative pressure decreases on the upstream side where the flow velocity is low.
As described above, the flow of the fluid between the suction surface and the work is symmetrical with respect to the first straight line passing through the center of the blowout hole and extending in the direction of the speed reduction. And the flow is asymmetric with respect to the second straight line extending in the direction orthogonal to the first straight line.
[0011]
In addition, the force for driving the work generated by the viscous frictional force of the fluid increases with an increase in the flow velocity, and is generated from a higher static pressure side to a lower static pressure side. Therefore, the force for driving the workpiece to the downstream side due to the viscous friction force or the like is larger than the force for driving the work to the upstream side. Therefore, the thrust generated by the difference between the driving forces acts to move the work to the downstream side.
[0012]
Therefore, a thrust in a predetermined direction determined by the direction in which the blowout hole is inclined can be applied to the work while adsorbing the work in a non-contact manner.
[0013]
According to the second aspect of the present invention, since the blowout hole is formed to extend in an angle range of 15 to 60 degrees with respect to a direction perpendicular to the suction surface, the work can be sufficiently suctioned. , A sufficiently large speed can be obtained. Therefore, a sufficiently large thrust can be applied to the work while reliably sucking the work.
[0014]
The direction in which the blowout hole extends is set in the range of 15 to 60 degrees as described above. When the direction is less than 15 degrees, the minute speed decreases and a sufficiently large thrust is applied to the work. If it exceeds 60 degrees, the flow velocity on the downstream side will be larger, but the flow velocity on the upstream side will be smaller, and the distribution of the flow velocity will be too biased to one side. This is because the force for adsorbing the phenol is reduced.
[0015]
According to the third aspect of the present invention, since the axial length of the outlet is formed to be three times or more the diameter of the outlet, the fluid is guided by the outlet and flows along the outlet. After that, it is ejected from the outlet. Therefore, it is possible to reliably generate a predetermined thrust according to the inclination of the outlet.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
The thrust generating type non-contact suction means 1 shown in this embodiment is formed in a disk shape as shown in FIGS. 1 to 3, and has an opening on one surface, that is, a flat suction surface 11. Using a negative pressure generated when air (fluid) ejected from the ejection hole 12 flows through the narrow gap 2 between the suction surface 11 and the surface Wka of the flat work Wk. The work Wk is attracted in a non-contact manner.
[0018]
The blow-out hole 12 has a circular cross section, opens at the center of the suction surface 11, and extends linearly at an angle of 15 to 60 degrees with respect to a direction perpendicular to the suction surface 11. It is formed to exist. That is, the angle θ between the axis L of the blow-off hole 12 and the center line C of the thrust generating type non-contact suction means 1 which is a straight line in a direction orthogonal to the suction surface 11 is set to 15 to 60 degrees.
Further, the length of the blowout hole 12 in the axial direction is set to be three times or more the diameter of the blowout hole 12. In this embodiment, the diameter of the blowout hole 12 is 2 mm, and the length in the axial direction is 6 mm or more.
[0019]
Further, the thrust generating type non-contact suction means 1 is integrally formed of an acrylic resin (PMMA). However, it may be formed of a synthetic resin other than acrylic, a metal such as aluminum or stainless steel, or another material.
[0020]
In the thrust generating type non-contact suction means 1 configured as described above, the air ejected from the blowing holes 12 flows through the narrow gap 2 between the suction surface 11 and the surface Wka of the work Wk, thereby increasing the speed. The static pressure P of the air becomes low according to Bernoulli's law. In this case, the static pressure P becomes a negative pressure lower than the atmospheric pressure, so that the work Wk can be suction-held.
[0021]
On the other hand, since the blowout holes 12 are formed obliquely to the direction orthogonal to the suction surface 11, the air blown out from the blowout holes 12 has a partial velocity in the direction along the suction surface 11 on the blowout side. Will have. Therefore, the air ejected from the outlet 12 theoretically has a speed component obtained by synthesizing the component of the speed concentrically spreading from the outlet 12 and the component of the above-mentioned partial speed. Therefore, the flow velocity on the downstream side in the above-mentioned speed-dividing direction becomes relatively high, and the flow velocity on the upstream side in the above-mentioned speed-dividing direction becomes relatively slow with respect to the outlet hole 12. As shown in FIG. 1B, the absolute value of the negative pressure indicated by the static pressure P increases on the downstream side where the flow velocity is high, and the absolute value of the negative pressure decreases on the upstream side where the flow velocity is low.
As described above, the flow of air in the narrow gap 2 is symmetrical with respect to the first straight line L1 (see FIG. 2A) extending through the center of the blowout hole 12 and extending in the above-described speed-dividing direction. However, the flow is asymmetric with respect to the second straight line L2 (see FIG. 2A) extending in the direction orthogonal to the first straight line L1 through the center of the outlet hole 12.
[0022]
Further, the force for driving the work Wk generated by the viscous frictional force of the air increases with an increase in the flow velocity, and is generated from the higher side of the static pressure P toward the lower side. For this reason, the force for driving the work Wk to the downstream side due to the viscous friction force or the like is larger than the force for driving the work Wk to the upstream side. Therefore, the thrust generated by the difference between the driving forces acts to move the work Wk to the downstream side.
[0023]
In addition, since the axial length of the blowout hole 12 is formed to be three times or more the diameter of the blowout hole 12, air is sufficiently guided by the blowout hole 12 to flow in the direction along the blowout hole 12. Become. Therefore, air can be reliably ejected in the direction in which the blowout holes 12 extend.
[0024]
Moreover, since the direction in which the blowout holes 12 extend is inclined at an angle of 15 to 60 degrees with respect to the center line C, the work Wk can be sucked with a sufficiently large force, and at the same time, the work speed is sufficiently large as the above-mentioned partial speed. Things are obtained.
[0025]
Therefore, a sufficiently large thrust can be applied to the work Wk while reliably sucking the work Wk. Further, the thrust can be applied in a predetermined direction determined by the direction in which the blowout hole 12 is inclined.
[0026]
Further, by providing at least three thrust generating type non-contact suction means 1 configured as described above so that the thrusts are balanced, a plate-like sheet glass or the like can be used without using a positioning means such as a stopper. The work Wk can be held at a predetermined position.
[0027]
Further, when the thrust generating type non-contact suction means 1 is used for transporting a work Wk such as a postcard, a ticket, a regular ticket, or the like, a conventional method using a belt conveyor or the like for the transport is used. As a result, it is possible to improve the transfer speed, reduce the size of the transfer device, reduce failures and costs, and the like.
[0028]
The reason for setting the angle θ in the range of 15 to 60 degrees is that if the angle θ is less than 15 degrees, the above-described minute speed decreases, and it becomes impossible to apply a sufficiently large thrust to the work Wk. If the angle exceeds 60 degrees, the flow velocity on the downstream side becomes larger, but the flow velocity on the upstream side becomes smaller, and the distribution of the flow velocity becomes too biased to one side. This is because it will decrease. However, angles other than the above angle range are not excluded.
[0029]
In the above embodiment, an example in which air is used as the fluid has been described. However, other fluid such as water can be used instead of the air.
[0030]
【Example】
Next, an embodiment of the present invention will be described. Here, the thrust-generating type non-contact suction means shown in FIGS. 2 and 3 is used as the first embodiment and the second embodiment, respectively, and the pressure (especially, the static pressure) of the slit 2 is measured for each of these embodiments. A first experiment and a second experiment to measure the maximum adsorption load were performed.
[0031]
1. Experimental conditions Diameter of adsorption surface 11 such as specifications of the first and second embodiments: 50 mm
Work surface diameter: 49mm
Diameter of blow hole 12: 2.0 mm
Length of blow-out hole 12: first embodiment = 6.0 mm, second embodiment = 8.0 mm
Angle θ: 1st embodiment = 15 degrees, 2nd embodiment = 60 degrees Fluid to be supplied to outlet 12: Industrial compressed air pressure measurement position of maximum 0.5 MPa: Downstream from center of opening 12 a of outlet 12 , Measured from the work Wk side at predetermined intervals in the upstream, right and horizontal directions.
Further, if the respective directions of the downstream, the upstream, and the right side are more accurately defined, they are as follows. That is, in FIG. 2 and FIG. 3, when the axis L of the blowing hole 12 is projected on the suction surface 11 in FIGS. 2 and 3, the direction in which air is ejected on the projected axis (corresponding to the first straight line) L1 The upstream direction refers to a direction opposite to the downstream direction, and the right lateral direction refers to the right direction of the projection axis L1 in plan view.
[0032]
2. Experimental Results and Discussion of First Experiment FIGS. 4 and 5 show the first experimental results. In the case of the first embodiment shown in FIG. 4, the angle θ is 15 degrees, and the direction in which the blowout holes 12 extend is close to the direction orthogonal to the suction surface 11. A pressure zone was obtained. Therefore, it can be estimated that a sufficiently large adsorption force is obtained.
On the other hand, in the case of the second embodiment shown in FIG. 5, the angle θ is 60 degrees, and the direction in which the blowout holes 12 extend is considerably inclined with respect to the direction orthogonal to the suction surface 11. As a result, the result was that the upstream negative pressure was not sufficiently obtained. However, since the negative pressure on the downstream side and the right side is sufficiently obtained, it can be estimated that although a lowering of the attraction force is expected as compared with the first embodiment, an inconvenient attraction force can be obtained.
[0033]
4 and 5, ro is a position corresponding to the opening edge of the blowout hole 12, P is a pressure in the narrow gap 2 measured from the work Wk side, and substantially inside the position of the radius ro. The pressure becomes equal to the total pressure Po described later, and becomes a value obtained by measuring the static pressure of the air in the narrow gap 2 substantially outside the position of the radius ro. Po is the total pressure of the air supplied from the blowing holes 12, and Pa is the atmospheric pressure.
In FIGS. 4 and 5,
(P-Pa) / (Po-Pa)
Is calculated to make the measurement pressure P dimensionless.
[0034]
3. Experimental Results and Discussion of the Second Experiment FIGS. 6 and 7 show the results of the second experiment. As a result of this experiment, it was confirmed that the maximum suction load was increased by increasing the flow rate of the air ejected from the blowing holes 12. In addition, the maximum suction load of the first embodiment shown in FIG. 6 is larger than the maximum suction load of the second embodiment in which the angle θ shown in FIG. . However, also in the second example, it was confirmed that a sufficiently large maximum suction load without any inconvenience in adsorbing the work Wk was obtained.
[0035]
6 and 7, the flow rate Q is a normal flow rate value instructed by the flow meter, and the corrected flow rate Qn is caused by a difference between a design pressure (0.6 MPa) of the flow meter and an actually measured pressure. This is the normal flow value after correcting the flow difference.
[0036]
As a result, when the angle θ is in the range of 15 to 60 degrees, the work Wk can be suctioned with a sufficiently large force.
[0037]
Further, the thrust for driving the work Wk along the suction surface 11 increases as the angle θ increases.
Therefore, when a relatively heavy work Wk such as an iron plate or a glass plate is transferred, by using the work with the angle θ approaching 15 degrees, the work Wk can be surely absorbed and transferred. And the thrust can be balanced and held at a predetermined position.
When conveying a relatively light work Wk such as a sheet of paper or plastic (synthetic resin) such as a postcard, a ticket, a regular ticket, or the like, the angle θ is set to be close to 60 degrees. Thus, the work Wk can be transferred at a high speed.
[0038]
【The invention's effect】
As described above, according to the first to third aspects of the present invention, the static pressure of the fluid flowing through the narrow space between the suction surface and the surface of the work becomes a negative pressure lower than the atmospheric pressure. Can be held by suction.
[0039]
Also, since the outlet is formed obliquely to the direction perpendicular to the suction surface, the fluid ejected from the outlet has a partial velocity in the direction along the suction surface on the side where the fluid is ejected. Become. Therefore, between the suction surface and the work, the flow velocity on the downstream side in the above-mentioned speed-dividing direction becomes relatively high, and the flow velocity on the upstream side in the above-mentioned speed-dividing direction becomes relatively slow. On the side where the flow velocity is high, the absolute value of the negative pressure becomes large, and the viscous frictional force of the fluid acts greatly. Therefore, the workpiece is moved toward the downstream side in the above-mentioned speed dividing direction. Thrust will be generated.
[0040]
Therefore, a thrust in a predetermined direction determined by the direction in which the blowout hole is inclined can be applied to the work while adsorbing the work in a non-contact manner.
[0041]
According to the second aspect of the present invention, since the blowout hole is formed to extend in an angle range of 15 to 60 degrees with respect to a direction orthogonal to the suction surface, the work can be sufficiently suctioned. At the same time, it is possible to obtain a sufficiently large speed as the above-mentioned minute speed. Therefore, a sufficiently large thrust can be applied to the work while reliably sucking the work.
[0042]
According to the third aspect of the present invention, since the axial length of the outlet is formed to be three times or more the diameter of the outlet, the fluid is guided by the outlet and flows along the outlet. After that, the gas is blown out from the outlet. Therefore, it is possible to reliably generate a predetermined thrust according to the inclination of the outlet.
[Brief description of the drawings]
FIG. 1 is a diagram showing a thrust generating type non-contact suction means shown as an embodiment of the present invention, wherein (a) is a cross-sectional view, and (b) is air flowing along a first straight line. FIG. 4 is an explanatory diagram showing a pressure distribution of FIG.
FIGS. 2A and 2B are diagrams showing the thrust generating type non-contact suction means (angle θ = 15 degrees), wherein FIG. 2A is a plan view and FIG.
FIGS. 3A and 3B are diagrams showing the same thrust generating type non-contact suction means (angle θ = 60 degrees), wherein FIG. 3A is a plan view and FIG.
FIG. 4 is a diagram illustrating a first experimental result according to the first embodiment of the present invention, and is a diagram illustrating a pressure distribution of air flowing along an adsorption surface at an angle θ = 15 degrees.
FIG. 5 is a diagram illustrating a first experimental result according to the second embodiment of the present invention, and is a diagram illustrating a pressure distribution of air flowing along an adsorption surface at an angle θ = 60 degrees.
FIG. 6 is a diagram illustrating a second experimental result according to the first embodiment of the present invention, and is a diagram illustrating a relationship between an ejection flow rate from an ejection hole and an maximum suction load at an angle θ = 15 degrees.
FIG. 7 is a diagram illustrating a second experimental result according to the second embodiment of the present invention, and is a diagram illustrating a relationship between a blowout flow rate from an outlet and a maximum suction load at an angle θ = 60 degrees.
FIGS. 8A and 8B are views of a non-contact suction means shown as a conventional example, in which FIG. 8A is a cross-sectional view and FIG. 8B is an explanatory view showing a pressure distribution of a gas flowing along an adsorption surface.
[Explanation of symbols]
11 suction surface 12 blow-out hole C center line L axis
Wk work
Wka surface θ angle

Claims (3)

A suction hole for the fluid is provided on the suction surface, and the work is suctioned in a non-contact manner by utilizing a negative pressure generated when the fluid ejected from the blow hole flows between the suction surface and the surface of the work. So that
The thrust generating type non-contact suction means, wherein the blowout hole extends obliquely with respect to a direction orthogonal to the suction surface. The thrust-generating non-contact suction means according to claim 1, wherein the blow-out hole extends at an angle of 15 to 60 degrees with respect to a direction orthogonal to the suction surface. The thrust-generating non-contact suction means according to claim 1 or 2, wherein the length of the blow-out hole in the axial direction is at least three times the diameter.

Images