JPH0885086A - Vacuum gripping device - Google Patents

Abstract

PURPOSE: To provide a vacuum gripping device capable of restraining air pressure from being lowered caused by ineffectivesuction without providing any complicate vacuum pressure control mechanism, and exhibiting high sucking performance without being affected by the shape of a work. CONSTITUTION: A vacuum gripping device VD1 is provided with a cylinder 11, a first air passage 12 connected to the upper end of the cylinder 11, a second air passage 13 connected to the lower end of the cylinder 11, a main body 10 provided with a ball 14 as a spherical blocking member, and a suction pad 20 to be attached to the lower surface of the main body 10. A first auxiliary air passage 18 is formed near a second connecting part 16. This first auxiliary air passage 18 is a passage for easily forming an air passage from the lower side of the suction pad 20 to the cylinder 11 in the suction initial stage, and an air passage is formed without waiting the state where the ball 14 is moved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripping device for gripping a work when the work is supplied to a predetermined position in a manufacturing line, a transfer line or the like, and more specifically, by a suction force generated by a vacuum pump or the like. The present invention relates to a vacuum gripping device for sucking and gripping a work.

[0002]

2. Description of the Related Art Conventionally, in a manufacturing line or the like, a transfer device (feeder) is used to transfer and supply a work to a predetermined position. This feeder is provided with a gripping device for gripping a work and a moving device for moving the gripped work together with the gripping device to a predetermined position.

As a gripping device, a gripping member is generally used for actually gripping a work by a gripping member, but it is difficult to control the gripping force for gripping the work in this type of gripping device. That is, when the gripping force is strong, the work is damaged, and when the gripping force is weak, the work cannot be reliably gripped.

Therefore, using a suction device such as a vacuum pump,
Various vacuum gripping devices for gripping a work by suction have been proposed and put into practical use. Here, a general vacuum gripping device VD4 will be described with reference to FIG.

The vacuum gripping device VD4 is equipped with a vacuum pump 50 for generating a negative pressure for adsorbing a work, and a vacuum pad 51 for adhering the work in close contact with the work. The vacuum pump 50 and the vacuum pad 51 are different from each other. , Are connected by a connection pipe 52. Further, the vacuum gripping device VD4 includes a compressor 54 for removing the work adsorbed on the vacuum pad 51, and a vacuum pump 5.
Switching valve 55 for switching between 0 and the compressor 54
It has.

A skirt made of a rubber material is attached to a portion of the vacuum pad 51 which is in direct contact with the work to increase the effective suction area and improve the adhesion to the work. Then, when the skirt and the work come into contact with each other, a small space is formed inside the skirt, so that the air existing in the small space is efficiently sucked.

In the vacuum gripping device VD4 having such a structure, the vacuum pump 50 is normally in operation at all times, and the work to be gripped is attracted (gripped) by bringing the vacuum pad 51 into contact with the work. At this time,
The work is adsorbed so as to be sucked up from above, and the gravity acting on the work and the suction force of the vacuum pump 50 are on the same line of action. Therefore, unlike the case where the gripping force of the gripping member and the gravity acting on the work are orthogonal to each other, the work is not damaged by the frictional force generated between the work and the gripping member. Further, the gripping force does not damage the work.

When the work adsorbed on the vacuum pad 51 is to be released, the work is released by switching the switching valve 55 to the compressor 54 side and sending compressed air toward the vacuum pad 51.

Here, the ability to adsorb a work in the vacuum gripping device is determined by the adsorbing effective area of the vacuum pad and the ultimate vacuum pressure when adsorbing a non-air-permeable work. Not affected. on the other hand,
In the case of adsorbing a breathable work, air flows into the skirt through the breathable work, so the ability to adsorb the work is determined by the displacement of the vacuum pump.

[0010]

However, in the conventional vacuum gripping device VD4, when the vacuum gripping device VD4 is provided with the plurality of vacuum pads 51 via the branch pipe 52, depending on the shape of the work, the vacuum suction is performed. There is a problem in that the vacuum pad 51 that does not exist is present and the vacuum pressure decreases. That is, since each vacuum pad 51 is connected to one vacuum pump 50,
If some of the vacuum pads 51 suck air, the total vacuum pressure will drop.

When the vacuum pressure is lowered in this way, the other vacuum pad 51 that is adsorbing the work cannot reliably adsorb the work, and the work is gripped in an unstable state or dropped during conveyance. There was a risk of doing it.

In order to solve such a problem, the vacuum gripping device VD4 having a plurality of vacuum pads 51 has an air suction sensor for detecting whether or not the vacuum pad 51 is performing air suction, and suction (air suction). Each vacuum pad 51 is provided with a control device 53 including a switching valve for switching on / off of the vacuum pad 51 for inhalation. And a certain vacuum pad 5
When the air suction sensor in the control device 53 detects that 1 is sucking air, the changeover valve corresponding to the vacuum pad is closed to prevent the vacuum pressure from decreasing.

However, such a vacuum gripping device V
In D4, each vacuum pad 51 must be provided with a control device 53, which causes a problem that the entire device becomes large and the control mechanism becomes complicated. Therefore, there is a problem in that the work transfer efficiency also deteriorates, which in turn deteriorates the product manufacturing efficiency.

Further, the conventional vacuum gripping device VD4 exhibits a relatively good adsorption performance for a work having a larger surface area than the skirt of the vacuum pad 51, but for a work having a smaller surface area than the skirt, Even the vacuum gripping device VD4 having a plurality of vacuum pads 51 could not be sucked.

In such a case, by using a dedicated vacuum pad, the work can be adsorbed, but for that purpose, the positional relationship between the work and the vacuum pad must be accurately controlled, and the work is Accordingly, the vacuum pad had to be replaced, which was very complicated.

The present invention has been made to solve the above-mentioned conventional problems, and a vacuum capable of suppressing a decrease in vacuum pressure due to air suction without providing a complicated vacuum pressure control mechanism. An object is to provide a gripping device. It is another object of the present invention to provide a vacuum gripping device that exhibits good suction performance regardless of the shape of the work.

[0017]

In order to achieve the above object, a vacuum gripping device according to a first aspect of the present invention has a cylinder and a diameter smaller than the diameter of the cylinder, and one end of the cylinder and a first connection. A first air passage that is connected via a section, and is movably provided inside the cylinder,
A spherical closing member that closes the first air passage, and a second diameter that is smaller than the diameter of the cylinder, is connected to the other end of the cylinder, and can be closed by the spherical closing member.
An air passage and a first auxiliary air passage that is formed at a second connecting portion between the other end of the cylinder and the second air passage and cannot be closed by the spherical closing member are provided.

Here, it is preferable that a spherical closing member contact portion for contacting the first air passage and the spherical closing member is formed in the first connecting portion. Also,
It is desirable that a second auxiliary air passage that connects the cylinder and the first air passage be formed near the first connecting portion. Further, it is preferable that a suction member for facilitating suction of the work is attached to the second air passage.

Next, the vacuum gripping device according to the second invention is
A cylinder chamber, a third air passage having a diameter smaller than that of the cylinder chamber, and connected to one end of the cylinder chamber via a third connecting portion, and movably provided inside the cylinder chamber. And a spherical closing member that closes the third air passage, and a diameter that is smaller than the diameter of the cylinder chamber, is connected to the other end of the cylinder chamber, and can be closed by the spherical closing member. An air passage, a fourth of the other end of the cylinder chamber and the fourth air passage,
A plurality of adsorption units, each of which is formed in the connecting portion and includes a third auxiliary air passage that cannot be closed by the spherical closing member, are arranged in the same plane, and each third air passage of the plurality of adsorption units is The chamber is connected to the chamber.

Here, it is desirable that a spherical closing member contact portion for contacting the third air passage and the spherical closing member is formed in the third connecting portion. Also,
It is preferable that a suction member that facilitates suction of the work is attached to an outer portion of the fourth air passage.

[0021]

In the vacuum gripping device according to the first aspect of the present invention having the above structure, when suction is started from the first air passage by the suction device such as a vacuum pump, the outside of the second air passage opened to the atmosphere. From, the air flows toward the inside of the cylinder and escapes to the first air passage. The spherical closing member is locked to the second connecting portion that connects the other end of the cylinder and the second air passage when the suction is started.

When the work is in contact with the atmosphere side of the second air passage, the air existing between the work and the second connecting portion is the first auxiliary formed in the second connecting portion. It escapes from the air passage to the first air passage. Here, since the amount of air existing between the work and the second connecting portion is finite, the air pressure difference between the first air passage side and the second air passage side of the spherical closing member is eliminated with the passage of time. To go.

That is, it becomes impossible to supply (suck) the air amount corresponding to the air amount sucked from the first air passage from the second air passage side, and it is formed from the second air passage to the first air passage. The pressure from the first air passage to the surface of the work becomes the same vacuum pressure by blocking the air flow path that has been performed.

As a result, the pressures on the first air passage side and the second air passage side of the spherical closing member become the same, the spherical closing member moves toward the first air passage and is not closed, and the work is It is attracted to the vacuum gripping device by the negative pressure and is in a gripped state. Here, when the adsorption member is attached to the atmosphere side of the second air passage, the adsorption effective area for adsorbing the workpiece increases and the adsorption capacity improves, so that the workpiece is adsorbed more reliably.

When the adsorbed work is released, the work is released from the vacuum gripping device by sending compressed air from the first air passage to the second air passage.

On the other hand, when the work is not in contact with the atmosphere side of the second air passage, the air flowing in from the second air passage first escapes from the first auxiliary air passage to the first air passage. To go. However, unlike the case where the workpiece is in contact, there is no limit on the amount of inflowing air, so the air pressure difference between the first air passage side and the second air passage side of the spherical closing member increases with the passage of time, but this is resolved. It will not be done.

That is, since the air amount corresponding to the air amount sucked from the first air passage is continuously supplied from the second air passage, the air flow passage formed from the second air passage to the first air passage. Is never shut off. Therefore, the first auxiliary air passage alone cannot handle the amount of air flowing in from the atmosphere side of the second air passage, and gradually the air begins to flow directly into the cylinder from the second air passage.

As a result, the spherical closing member moves toward the first air passage due to the airflow flowing directly into the cylinder from the second air passage and the airflow generated in the gap between the spherical closing member and the cylinder wall. To start. Then, finally, the spherical blocking member comes into close contact with the first connecting portion, and the flow of air from the second air passage to the first air passage is blocked.
In this way, by blocking the air flow from the second air passage to the first air passage, it is possible to reliably and easily prevent the vacuum gripping device having no workpiece from sucking air.

At this time, when the spherical closing member contact portion is formed in the first connecting portion, the spherical closing member is surely brought into close contact with the first connecting portion, and idle suction is prevented. Then, when the work is detached, the compressed air is sent from the first air passage to the second air passage even in the vacuum suction device for air suction, and the close contact state is released. That is, in the state where the spherical closing member is in close contact with the first connecting portion (spherical closing member close contact portion), the air flow path is blocked, so that the next time the workpiece is abutted, it will not immediately adsorb the workpiece. Because you can't.

When the second auxiliary air passage is formed near the first connecting portion, even if the spherical closing member is in close contact with the first connecting portion (spherical closing member contact portion),
A slight empty suction occurs, and the suction responsiveness when the work is brought into contact next time is improved. That is, by providing the second auxiliary air passage, the air passage is not completely blocked, so that the work can be immediately adsorbed. Since the air passage is not completely blocked, some suction may occur, but by determining the diameter of the second auxiliary air passage in consideration of the vacuum pump capacity, the suction capacity will not decrease due to the suction. To be prevented.

Next, in the vacuum gripping apparatus according to the fifth aspect of the present invention, when air in the chamber is started to be sucked by a suction device such as a vacuum pump, a plurality of suction units connected to the chamber suction the work. Is started.

That is, when the air in the chamber is sucked, from the outside of the fourth air passage open to the atmosphere,
Air flows into the cylinder chamber, and the air that has flowed into the cylinder chamber escapes from the third air passage to the chamber. The spherical closing member is locked to the fourth connecting portion that connects the other end of the cylinder and the fourth air passage when the suction is started.

Here, in the vacuum gripping apparatus according to the invention of claim 5, since a plurality of suction units are arranged in the same plane to constitute one vacuum gripping apparatus,
When the work is brought into contact with each other, the operation differs between each unit corresponding to the position where the work exists and each unit corresponding to the position where the work does not exist.

That is, in each suction unit corresponding to the position where the work is present, when the air in the space formed between the work and the fourth air passage is sucked and all the air in the space is sucked. , The pressure from the chamber to the space becomes the same vacuum pressure, and the work is adsorbed by the vacuum gripping device. At this time, the spherical blocking member remains locked to the fourth connecting portion and does not move toward the third connecting portion.

On the other hand, in each adsorption unit corresponding to the position where the work does not exist, since there is no limit on the amount of air flowing from the fourth air passage toward the chamber, the chamber side of the spherical closing member and the fourth air passage side. A pressure difference is generated between the spherical blocking member and the spherical blocking member, and the spherical blocking member moves toward the third connecting portion. Then, the air flow path which is in close contact with the third connecting portion and is formed from the fourth air passage toward the chamber is blocked, and air suction is suppressed.

Therefore, even when each suction unit is connected to one chamber, it is possible to prevent the vacuum pressure degree in the chamber from being lowered by the air suction from the suction unit corresponding to the non-working position. Thus, the suction performance of the work by the suction unit corresponding to the work existing position is maintained.

When the adsorbed work is released, compressed air is sent from the chamber into the cylinder chamber so that the pressure of the work on the side of the vacuum gripping device is higher than the pressure of the work on the atmosphere side. To leave.

Regarding the detailed operation of the vacuum gripping device according to the invention of claim 5 and the operation when the spherical closing member contact portion is formed in the third connecting portion, the vacuum according to the invention of claim 1 is obtained. Since each operation is the same as that of the gripping device, the description thereof will be omitted.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments in which the present invention is embodied in a vacuum gripping device will be described below with reference to the drawings.

First, the vacuum gripping device VD according to the first embodiment.
The configuration of No. 1 will be described with reference to FIGS. The vacuum gripping device VD1 includes a cylinder 11, a first air passage 12 connected to an upper end of the cylinder 11, a second air passage 13 connected to a lower end of the cylinder 11, and a ball 14 as a spherical closing member. 10 and a suction pad 20 mounted on the lower surface of the main body 10.

The cylinder 10 is arranged in the center of the main body 10, the upper end surface thereof is formed with a first connecting portion 15 to which the first air passage 12 is connected, and the lower end surface thereof is formed. A second connecting portion 16 is formed to which the second air passage 13 is connected.

The first air passage 12 is a passage having a diameter smaller than the diameter of the cylinder 11, is located on the same axis as the cylinder 11, and its lower end portion is connected to the cylinder through the first connecting portion 15. It is connected with 11. Further, a connection pipe JP that connects the vacuum gripping device VD1 and a vacuum pump (not shown) is connected to the upper end portion thereof.
When adsorbing, the air in the cylinder 11 is the first
The air flows out through the air passage 12 toward the vacuum pump, and at the time of separation, the compressed air from the compressor flows through the first air passage 12 into the cylinder 11.

In addition, the first connecting portion 15 is formed with a tapered ball contact portion 17 having a diameter corresponding to the diameter of the ball 14 in order to improve the adhesion when the ball 14 comes into close contact with the first connecting portion 15. Has been done.

The second air passage 13 is a passage having a diameter smaller than that of the cylinder 11, is located on the same axis as the cylinder 11, and its upper end portion is at the upper end thereof.
It is connected to the cylinder 11 via 6. The suction pad 20 is attached to the lower end (opening) of the filter 23 through a filter 23. And when adsorbing,
Air on the lower side of the suction pad 20 (outside the vacuum gripping device VD1) flows into the cylinder 11 through the second air passage 13, and when the air is released, the compressor and the cylinder 1
The compressed air from 1 flows out toward the lower side of the adsorption pad 20 through the second air passage 13.

Here, in the vicinity of the second connecting portion 16, the first
An auxiliary air passage 18 is formed. The first auxiliary air passage 18 is a passage for easily forming an air flow passage from the lower side of the suction pad 20 to the cylinder 11 in the initial stage of suction, without waiting for the ball 14 to move. An air passage is formed.

The first auxiliary air passage 18 will be further described with reference to FIG. FIG. 2 shows the vacuum gripping device V in FIG.
A cross section taken along line XX of D1 is shown, for a total of 3
One first auxiliary air passage 18 is formed. It can be seen that the second air passage 13 is closed by the lower portion of the ball 14, but the first auxiliary air passage 18 is not closed by the lower portion of the ball 14. Therefore, even when the second air passage 13 is closed by the balls 14, air easily flows into the cylinder 11 from the outside of the vacuum gripping device VD1.

The first auxiliary air passage 18 has a second
Since the function can be exhibited if it is formed outside the contact area between the air passage 13 and the ball 14, one elliptical deformation hole 19 may be formed as shown in FIG.

The ball 14 is contained in the cylinder 11 and is formed to have a diameter smaller than the diameter of the cylinder 11 by a predetermined length. Further, before the suction is started, it is stationary while being locked to the second connecting portion 16, and after the suction is started, different behaviors are exhibited depending on the presence or absence of the work W. The diameter of the ball 14 is determined by the material of the ball 14 and the diameter of the cylinder 11. If the diameter is too large, rapid movement of the ball 14 is hindered, and if the diameter is too small, the ball 14 is too large. Reacts hypersensitively.

The suction pad 20 is made of a soft material so as to conform to the shape of the surface of the work W to be sucked, and has a connection passage 22 connected to the second air passage 13 and a lower portion for ensuring an effective suction area. It is provided with a suction portion 21 that opens in a skirt shape toward the side. Here, as the soft material, for example, soft rubber such as foamed urethane is suitable.

The filter 23 is interposed between the upper side surface of the suction pad 20 and the lower side surface of the main body 10. When sucking the outside air, dust and the like enter the inside of the cylinder 11,
This prevents the movement of the ball 14 and the adhesion between the ball 14 and the ball contact portion 17 from being hindered.

Vacuum gripping device VD1 having the above structure
Corresponding to the shape and size of the work W, or one vacuum gripping device VD1 is used as one set. That is, if the work W is slightly larger than the suction pad 20, the work W can be performed with the 11 vacuum gripping devices VD.
This is because, when the work W has a large surface area, it can be carried only by using the plurality of vacuum gripping devices VD1.

Subsequently, the vacuum gripping device V according to the first embodiment.
The operation of D1 will be described with reference to FIGS.
For convenience of explanation, the operation when there is a work W to be sucked and the operation when there is no work W to be sucked will be described separately.

When the vacuum pump is started, the connecting pipe JP
The air in the cylinder 11 starts to be sucked from the first air passage 12 via the. Then, air flows from the outside of the suction portion 21 of the suction pad 20 that is open to the atmosphere toward the inside of the cylinder 11 via the connection passage 22, and the inflowing air escapes to the first air passage 12. Is formed.

Here, the lower end surface of the main body 10 and the suction pad 20
Since the filter 23 is interposed between the upper end surface and the upper end surface, the amount of dust and the like in the air mixed in the cylinder 11 is suppressed. That is, when dust or the like is mixed in the cylinder 11 and intervenes between the ball 14 and the ball close contact portion 17, the close contact between the two deteriorates, and the suction capacity during idle suction decreases. If dust is present in the gap between the ball 14 and the cylinder 11, the ball 14
Is deteriorated, and in the worst case, the ball 14 is locked in the middle of the cylinder 11.

Therefore, it becomes necessary to interpose the filter 23. It is assumed that the ball 14 is locked to the second connecting portion 16 that connects the other end of the cylinder 11 and the second air passage 13 at the beginning of suction.

First, with reference to FIG. 4, the operation of the vacuum gripping device VD1 when the work W to be attracted exists will be described. When the suction portion 21 of the suction pad 20 is brought into contact with the suction surface of the work W, a small space is formed between the suction surface of the work W and the suction portion 21 of the suction pad 20. Then, the air in the small space is not connected to the second connecting portion 16
It flows into the cylinder 11 from the first auxiliary air passage 18 formed in the vicinity, passes through the first air passage 12, and reaches the vacuum pump. Therefore, since the ball 14 moves upward and the second air passage 13 does not need to be opened, a relatively large suction force can be obtained from the beginning of suction.

In this case, most of the air sucked by the vacuum pump exists in the small space formed by the work W and the suction portion 21 of the suction pad 20, and the amount thereof is finite. is there. Therefore,
At the beginning of adsorption, the balls 14 and the second air passage 12 side
The air pressure difference existing between the air passage 13 side and the air passage 13 side is eliminated as the adsorption time elapses.

That is, it becomes impossible to supply (suction) the amount of air corresponding to the amount of air sucked from the first air passage 12 from the outside (atmosphere side) of the suction pad 20.
Workpiece W and suction section 2 of suction pad 20 from air passage 12
The pressure applied to the small space formed by 1 and 1 is the same.

As a result, the air passage formed from the second air passage 13 to the first air passage 12 disappears, and the pressures of the balls 14 on the first air passage 12 side and the second air passage 13 side are the same. Therefore, the ball 14 becomes the first connecting portion 15
The ball does not move toward the ball contact portion 17, and the first air passage 12 is not blocked. Therefore,
The air in the cylinder 11 is continuously sucked out from the first air passage 12, and the work W is adsorbed by the vacuum gripping device VD1 by the negative pressure (vacuum pressure) to be gripped.

At this time, since the adsorption effective area for adsorbing the work W is increased by the adsorption portion 21 of the adsorption pad 20, the adsorption pad 20 is not mounted and the second air passage 13 is not attached.
As compared with the case where the suction is performed depending on the diameter, the suction capacity is improved, and the work W is more reliably sucked.

Thus, the work W gripped by suction
Is moved to a predetermined position, then separated, and the conveyance is completed. Here, when the work W is released, the compressed air obtained by the compressor is supplied to the first air passage 12
The work W is detached by feeding the work W into the cylinder 11. That is, the work W is separated from the vacuum gripping device VD1 by making the pressure applied to the work W on the second air passage 13 side (adsorption part 21 side) higher than the pressure applied to the work W on the atmosphere side.

Next, the operation of the vacuum gripping device VD1 when there is no work W to be attracted will be described with reference to FIG. Even when the work W is not in contact with the suction pad 20, the air that has flowed in from the outside of the suction pad 20 does not contact the first auxiliary air passage 1 at the beginning of the suction.
8 through the cylinder 11 to the first air passage 12. However, unlike the case where the workpiece W is in contact, there is no limit to the amount of air flowing in from the suction pad 20, so that even if the suction time elapses, the first air passage 12 side of the ball 14 and the second air passage. The air pressure difference from the 13 side will not be eliminated.

That is, since the amount of air corresponding to the amount of air sucked from the first air passage 12 is continuously supplied from the outside of the adsorption portion 21, it is formed from the second air passage 13 to the first air passage 12. The air flow path is not blocked. Here, since the diameter of the first auxiliary air passage 18 is smaller than the diameter of the first air passage 12, only the first auxiliary air passage 18 gradually increases the amount of air sucked out from the first air passage 12. Second air passage 1
Air starts to flow from 3 directly into the cylinder 11.

As a result, the ball 14 moves into the second air passage 1
3 starts to levitate from the second connecting portion 16 by the flow of air directly flowing into the cylinder 11, and the ball 14
The air flow generated in the gap between the cylinder 11 and the wall of the cylinder 11 starts moving toward the first air passage 12. Then, finally, the ball 14 comes into close contact with the ball contact portion 17 of the first connecting portion 15, and the first air passage 12 is closed.

Therefore, the air flow path formed from the outside of the adsorption portion 21 to the first air passage 12 is blocked, and the air outside the adsorption pad 20 does not flow from the first air passage 12 toward the vacuum pump. Thus, the air suction by the vacuum gripping device VD1 in which the work W does not exist is reliably and easily suppressed.

When a plurality of vacuum gripping devices VD1 are used as one set, when the work W is detached from the other vacuum gripping device VD1 which is sucking the work W, the vacuum gripping device for idle suction is used. Compressed air is also sent to the VD1 from the first air passage 12 toward the attracted surface of the work W by the compressor.

As a result, the ball 14 and the ball contact portion 17
The close contact state with is released, and the ball 14 returns to the second connecting portion 16. This operation is performed because the ball 14 is in close contact with the ball contact portion 17, and the close contact may not be released only by stopping suction by the vacuum pump. Thus, in the state where the ball 14 and the ball contact portion 17 are in close contact with each other, the first air passage 12 remains closed, and the air flow path from the suction portion 21 of the suction pad 20 to the first air passage 12 is blocked. Has been done.

Therefore, even if the work W is abutted next time, the air in the small space formed by the suction portion 21 of the suction pad 20 and the suction surface of the work W cannot be sucked by the vacuum pump. , The work W cannot be adsorbed. Therefore, it is necessary to return the ball 14 to the second connecting portion 16.

Next, the vacuum gripping device VD according to the second embodiment.
The configuration of No. 2 will be described with reference to FIGS. 6 and 7. In the following embodiments, the same components as those of the vacuum gripping device VD1 according to the first embodiment or the components having the same functions are denoted by the reference numerals used in the first embodiment and the description thereof is omitted. However, the description will focus on the different configuration.

The vacuum gripping device VD2 according to the second embodiment is
The vacuum gripping device VD2 according to the first embodiment is different in that a second auxiliary air passage 30 is provided near the first connecting portion 15.

The second auxiliary air passage 30 has the ball contact portion 1
It is formed from the upper end surface of the cylinder 11 on the outside of 7 to the lower side surface of the first air passage 12. Then, as shown in the cross-sectional view taken along the line YY in FIG. 7, an air flow passage from the inside of the cylinder 11 to the first air passage 12 is secured even when the ball 14 is in close contact with the ball contact portion 17. .

Therefore, the vacuum suction device VD2 for empty suction
In the above, the work W can be attracted even when the ball 14 is in close contact with the ball contact portion 17.
Next, the operation of the vacuum gripping device VD2 according to the second embodiment will be described with reference to FIGS. 8 and 9.

FIG. 8 shows an operating state of the vacuum gripping device VD2 when there is a work W to be attracted. When the work W to be adsorbed exists, the air in the small space formed by the adsorbed surface of the work W and the adsorbing portion 21 of the adsorbing pad 20 becomes the total amount of air to be adsorbed, so that the second auxiliary air Whether the passage 30 is formed or not, there is no difference in the adsorption action. That is, the pressure from the attracted surface of the work W to the first air passage 12 reaches the vacuum pressure shortly after the suction is started, and the ball 1
No pressure difference occurs between the No. 4 first air passage 12 side and the suction pad 20 side. Therefore, the ball 14 moves toward the ball contact portion 17 and does not contact the ball contact portion 17, and the air in the cylinder 11 directly flows through the first air passage 12 having a larger diameter than the second auxiliary air passage 30. It is sucked through by a vacuum pump.

FIG. 9 shows an operating state of the vacuum gripping device VD2 when there is no work W to be attracted. When the work W does not exist, the cylinder 11
Since the amount of air sucked in is infinite, as described in the explanation of the operation in the first embodiment,
A pressure difference occurs between the air passage 12 side and the suction pad 20 side, and this pressure difference does not disappear even after a lapse of time.
Therefore, the ball 14 moves toward the ball contact portion 17 and contacts the ball contact portion 17, and the first air passage 12 is closed. As a result, the air flow path from the suction pad 20 to the first air passage 12 is blocked, and the work W cannot be sucked.

However, in the vacuum gripping device VD2 according to the second embodiment, the second auxiliary air passage 30 is formed near the first connecting portion 15. Therefore, even if the ball 14 is in close contact with the ball contact portion 17, the suction pad 2
The air flow path from 0 to the first air passage 12 is secured, and the adsorption responsiveness when the work W is brought into contact next time is improved.

That is, in the vacuum gripping device in which the second auxiliary air passage 30 is not formed, the compressed air is sent to separate the ball 14 that is in close contact with the ball contact portion 17 to re-form the air flow path. However, in the vacuum gripping device VD2 according to the second embodiment, the air flow path is always ensured without performing the work of detaching the ball 14. Therefore, it is not necessary to switch the suction of the air in the cylinder 11 and the feeding of the compressed air into the cylinder 11, and as long as the vacuum gripping device in which the work W is not sucked is always sucked by the vacuum pump. It's good.

Since the air flow path is not completely blocked, some air suction occurs, but the amount thereof is small compared to the case where the first air passage 12 is opened, and the vacuum pump is used. By determining the diameter of the second auxiliary air passage 30 in consideration of the capacity, a decrease in the adsorption capacity due to air suction is prevented.

Next, the vacuum gripping device VD according to the third embodiment.
The configuration of No. 3 will be described with reference to FIGS.
The vacuum gripping device VD3 includes a plurality of adsorption units VU formed inside the main body 40, a chamber 41 that connects the adsorption units VU above, a filter 42 arranged on the lower surface of the main body 40, and a lower surface of the filter 42. Is equipped with suction pads 43a and 43b.

The adsorption unit VU includes a cylinder chamber 44,
A third air passage 45 connected to the upper end of the cylinder chamber 44 via the third connecting portion 33, and a fourth air passage 4 connected to the lower end of the cylinder chamber 44 via the fourth connecting portion 34.
6 is provided. Further, the adsorption unit VU includes a third auxiliary air passage 32 formed in the fourth connecting portion 34, a ball 14 that is movably provided inside the cylinder chamber 44, and that closes the third air passage 45. .

The chamber 41 is connected to the third air passage 45 of each adsorption unit VU, and is also connected to a vacuum pump and a compressor (not shown). Then, the chamber 41 alternately sucks the air in the cylinder chamber 44 in each adsorption unit VU and pressure-feeds the air to the cylinder chamber 44 by switching electromagnetic valves (not shown).

The filter 42 is for preventing dust and the like in the atmosphere from being mixed into the cylinder chamber 44 when the work W is adsorbed, and has a structure in which the balls 14 move in the cylinder chamber 44. Vacuum gripping device VD3
Then, it is an essential component.

Unlike the suction pads 20 in the first and second embodiments, the suction pads 43a, 43b are not formed with a skirt-shaped suction portion 21 for enlarging the effective suction area, and are made of a soft rubber material. Is a flat plate-shaped suction pad. In addition, each suction unit VU is attached to the suction pad 43.
In, the suction holes 47a and 47b are formed in accordance with the position where the fourth air passage 46 is formed, and the hole diameter is determined by the workpiece W to be suctioned.

For example, as shown in FIG. 11, for a workpiece W1 having an edge such as a cup, the edge width W of the workpiece W1.
Suction pad 43 having suction holes 47a smaller than 11
As shown in FIG. 12, a suction hole 4 larger than the fourth air passage 46 is used for the work W having a large surface area.
The suction pad 43b having 7b is used.

Next, the vacuum gripping device V according to the third embodiment.
The operation of D3 will be described with reference to FIG. When a vacuum pump (not shown) is activated and suction is started, the air in the chamber 41 begins to flow in the direction of the arrow, and the air in the cylinder chamber 44 of each adsorption unit VU flows into the chamber 41. Then, outside air is sucked into the cylinder chamber 44 from the fourth air passage 46.

At this time, in the adsorption unit VU corresponding to the work existing position, the sucked outside air flows into the cylinder chamber 44 through the third auxiliary air passage 32, as described in the first embodiment, and the third Chamber 41 through air passage 45
Go out. Therefore, there is no pressure difference between the upper and lower sides of the ball 14, and the ball 14 does not come into contact with the ball contact portion 17.
It does not close the third air passage 45 by moving toward the ball contacting the ball contacting portion 17. As a result, the work W
The air existing in the space WS inside 1 is sucked by the vacuum pump, and the work W1 is suction-held by the suction pad 43a.

On the other hand, in the suction unit VU corresponding to the non-existence position of the work, since the amount of air passing through the third auxiliary air passage 32 is unlimited, a pressure difference is generated above and below the ball 14, and the ball 14 comes into contact with the ball. Stick to 17. Therefore, the third air passage 45 is closed, and idle suction is prevented.

In the vacuum gripping device VD3 shown in FIG. 12, only the difference is that the diameter of the suction hole 47b of the suction pad 43b is large and the work W2 has no space. Figure 1
The vacuum gripping device VD3 shown in FIG.

As described above in detail with reference to some embodiments, the vacuum gripping device VD according to each of the above embodiments.
1, VD2 and VD3 are the existence of the works W, W1 and W2,
Due to the difference in intake air amount due to the absence,
The air passages 12 and 45 are opened or closed.

Therefore, unlike the conventional vacuum gripping device in which the air passage is opened or closed by the external control processing device, it is not necessary to provide various sensors, solenoid valves and the like, so that the device can be simplified. it can. Also complex,
Since complicated control logic is not required, it is possible to improve the efficiency of the work W carrying work and the like. Also, the first
The vacuum gripping device VD1 according to the embodiment includes a first auxiliary air passage 18 that connects the second air passage 13 and the cylinder 11 in the vicinity of the second connecting portion 16.

Therefore, at the beginning of suction, the sucked outside air flows through the first auxiliary air passage 18 to the cylinder 11 and forms an air flow path leading to the first air passage 12, so that the work W is adsorbed. It has the advantage of improved response. That is, when the first auxiliary air passage 18 is not formed, the suction pad 20 is kept until the amount of air to be sucked in (fluid pressure) reaches a value for floating the ball 14.
Since the air flow path from the first air passage 12 to the first air passage 12 is not formed, a time lag occurs from the start of suction to the start of suction of the work W. However, since the first auxiliary air passage 18 is provided, an air flow passage is formed from the suction pad 20 to the first air passage 12 from the time when the intake air amount is small, so that the time lag is eliminated.

Further, the vacuum gripping device V according to the second embodiment.
The D2 is provided with a second auxiliary air passage 30 that connects the cylinder 11 and the first air passage 12 in the vicinity of the first connecting portion 15.

Therefore, the ball 14 is placed in the ball contact portion 1
Even when the work W is in close contact and the air flow path between the first air passage 12 and the cylinder 11 is blocked, the suction can be promptly started when the work W is abutted next time. . That is, by blocking the air flow path between the first air passage 12 and the cylinder 11, the air suction in the vacuum gripping device which does not adsorb the work W is suppressed, and in such a state, the adsorption of the work W does not occur. It is impossible.

However, by forming the second auxiliary air passage 30, even when the first air passage 12 is closed by the ball 14, the air in the cylinder 11 slightly flows into the first air passage 12. There is. As a result, the work of adsorbing the next work W can be immediately performed without performing the work of returning the ball 14 to the second connecting portion 16 once. Therefore, the work of carrying the work W or the like can be efficiently performed.

Furthermore, the vacuum gripping device VD3 according to the third embodiment has a structure in which a plurality of suction units VU are arranged in the same plane and the work W is sucked by the plurality of suction units VU. Therefore, the type of work W,
The work W can be adsorbed regardless of the shape or the like.

For example, in the vacuum gripping apparatus according to the first and second embodiments, since the suction pad 20 having the suction portion 21 is provided in order to expand the effective suction area, the work W1 having an edge such as a cup is provided. I couldn't aspirate. That is, since the suction portion 21 has a large opening area, even if the suction portion 21 is brought into contact with the edge of the cup or the like, outside air flows in, and an effective suction force cannot be obtained.

However, in the vacuum gripping device VD3 according to the third embodiment, the opening area of the cup is the effective suction area even if the effective suction area is not enlarged by the suction portion 21 having a large opening area. Adsorption time can be shortened by providing VUs densely.
Further, the airtightness is secured by making the opening areas of the suction holes 47a and 47b smaller than the edge area of the cup or the like. In such a case, the work W1 having an edge such as a cup
Can be adsorbed. Further, when the work W is heavy and has a large surface to be attracted, an effective attraction force can be obtained by enlarging the attraction hole.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the spirit of the present invention. It is easily guessed.

For example, in the present embodiment, the shapes of the first and third auxiliary air passages 18 and 32 are as shown in FIGS.
Alternatively, the ball 1 having the shape shown in FIG. 12 was used.
Any shape may be used as long as the second and fourth air passages 13 and 46 can communicate with the cylinder 11 and the cylinder chamber 44 in a state where 4 is locked to the second connecting portion 16.

The shape of the second auxiliary air passage 30 is as shown in FIG. 7, but when the ball 14 is in close contact with the ball contact portion 17, the cylinder 11 and the first air passage 12 are in contact with each other. The shape is not limited to this as long as it can communicate with air.

Further, the shape of the suction pads 20, 43a, 43b in each of the above-mentioned embodiments is not limited to that shown in the figure, and may be any shape corresponding to the shape of the work W to be suctioned.

Although not described in the claims, the technical idea grasped from the above-mentioned embodiment will be described below together with its effect. (1) In the vacuum gripping device according to any one of claims 1 to 4, the suction member facilitates suction of a workpiece by enlarging a suction effective area. Vacuum gripping device.

The suction force is determined by the suction effective area and the ultimate vacuum pressure, but it is difficult to improve the ultimate vacuum pressure. On the other hand, when such a configuration is provided, the suction force can be easily improved under the same ultimate vacuum pressure.

[0103]

As described above, the vacuum gripping device according to the present invention can suppress a decrease in vacuum pressure due to air suction without providing a complicated vacuum pressure control mechanism.

When the structure according to claim 5 is provided, good adsorption performance can be exhibited without being influenced by the shape of the work.

[Brief description of drawings]

FIG. 1 is a side view showing a side surface in section for explaining a configuration of a vacuum gripping device according to a first embodiment.

FIG. 2 shows the vacuum gripping device according to the first embodiment as X in FIG.
FIG. 3 is a plan sectional view taken along line X-ray.

FIG. 3 is a plan sectional view taken along line XX in FIG. 1 in a vacuum gripping device having a first auxiliary air passage having a different shape.

FIG. 4 is an explanatory view showing a working state when a work is in contact with a suction pad in the vacuum gripping apparatus according to the first embodiment.

FIG. 5 is an explanatory diagram showing an operation state in the case where the work is not in contact with the suction pad in the vacuum gripping apparatus according to the first embodiment.

FIG. 6 is a side view showing a cross section of a side surface for explaining the configuration of the vacuum gripping apparatus according to the second embodiment.

FIG. 7 shows a vacuum gripping device according to a second embodiment of FIG.
It is a plane sectional view cut by the -Y line.

FIG. 8 is an explanatory diagram showing an operation state when a work is in contact with the suction pad in the vacuum gripping apparatus according to the second embodiment.

FIG. 9 is an explanatory diagram showing an operation state in the case where the work is not in contact with the suction pad in the vacuum gripping device according to the second embodiment.

FIG. 10 is an overall perspective view for explaining an overall external configuration of a vacuum gripping device according to a third embodiment.

FIG. 11 is a first side view showing a cross section of a side surface for explaining the configuration of the vacuum gripping apparatus according to the third embodiment.

FIG. 12 is a second side view showing a side surface in section for explaining the configuration of the vacuum gripping apparatus according to the third embodiment.

FIG. 13 is an explanatory diagram showing an overall configuration of a vacuum gripping device according to a conventional example.

[Explanation of symbols]

10 ... Main body, 11 ... Cylinder, 12 ... First air passage, 1
3 ... 2nd air passage, 14 ... Ball, 15 ... 1st connection part,
16 ... 2nd connection part, 17 ... Ball contact part, 18 ... 1st auxiliary air passage, 20 ... Adsorption pad, 23 ... Filter, 3
0 ... second auxiliary air passage, 32 ... third auxiliary air passage, 33
... Third connecting portion, 34 ... Fourth connecting portion, 40 ... Main body, 41 ...
Chamber, VU ... Adsorption unit, W, W1, W2 ... Workpiece, VD1, VD2, VD3 ... Vacuum gripping device, VD4 ...
Vacuum gripping device according to conventional example

Claims (7)

[Claims] 1. A cylinder, and a first diameter having a diameter smaller than that of the cylinder and connected to one end of the cylinder via a first connecting portion.
An air passage, a spherical closing member that is movably provided inside the cylinder and closes the first air passage, and has a diameter smaller than that of the cylinder, and is connected to the other end of the cylinder, A second air passage that can be closed by the spherical closing member; and a first auxiliary air passage that is formed at the second connecting portion between the other end of the cylinder and the second air passage and that cannot be closed by the spherical closing member. A vacuum gripping device comprising: 2. The vacuum gripping device according to claim 1, wherein a spherical closing member contact portion for contacting the first air passage and the spherical closing member is formed in the first connecting portion. Vacuum gripping device characterized in that 3. The vacuum gripping device according to claim 1 or 2, wherein a second auxiliary air passage that connects the cylinder and the first air passage is formed near the first connecting portion. A vacuum gripping device characterized by being provided. 4. The vacuum gripping device according to any one of claims 1 to 3, wherein a suction member for facilitating suction of a work is attached to the outside of the second air passage. A vacuum gripping device characterized by being provided. 5. A cylinder chamber, a third air passage having a diameter smaller than that of the cylinder chamber, and connected to one end of the cylinder chamber via a third connecting portion, and the inside of the cylinder chamber. Is movably provided in
A spherical closing member that closes the third air passage, and a fourth air passage that has a diameter smaller than that of the cylinder chamber, is connected to the other end of the cylinder chamber, and can be closed by the spherical closing member. And a third auxiliary air passage which is formed at a fourth connecting portion between the other end of the cylinder chamber and the fourth air passage and cannot be closed by the spherical closing member, in the same plane. A vacuum gripping device, wherein a plurality of the suction units are arranged and each third air passage of the plurality of suction units is connected to a chamber. 6. The vacuum gripping device according to claim 5, wherein the third connecting portion is formed with a spherical closing member contact portion for closely contacting the third air passage and the spherical closing member. Vacuum gripping device characterized in that 7. The vacuum gripping device according to claim 5 or 6, wherein a suction member for facilitating suction of the work is attached to the outside of each of the fourth air passages. Vacuum gripping device.