JPH06330900A - Vacuum generator - Google Patents

Abstract

PURPOSE:To improve the release efficiency of vacuum by interconnecting an interval between a jet part of a nozzle and an external connecting hole at the operation of a spool valve element and also another interval between the supply source side of compressed air and an air tank, respectively. CONSTITUTION:This vacuum generator is provided with a vacuum generator body 2 in which a nozzle is installed, and a valve mechanism part 3 additionally installed in this body 2. This valve mechanism part 3 has an air tank 8, two external connecting holes 9 and 10 and a spool valve element 11. Especially this spool valve element 11 interconnects an interval between a jet part 1b of the nozzle 1 and the external connecting holes 9, 10, at the operation when compressed air is supplied, while it also interconnects another interval between the supply source side of the compressed air and the air tank 8. At the nonoperation when a supply of the compressed air is stopped, both these intervals between the jet part 1b of the nozzle 1 and the external connecting holes 9, 10 as well as the supply source side of the compressed air and the air tank 8 are cut off, and the interval between the external connecting holes 9, 10 and the air tank 8 is interconnected instead. Thus the compressed air is conducted into a suction pat 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum generator, and more particularly, when compressed air is injected from a nozzle, the air in the adsorption pad is discharged in accordance with the injection of the compressed air to generate a vacuum in the adsorption pad. The present invention relates to a vacuum generator that creates a state.

[0002]

2. Description of the Related Art A vacuum generating device for obtaining a vacuum by ejecting compressed air from a nozzle is used as a means for adsorbing a workpiece in an industrial robot or the like. In a vacuum generator used for such an application, a workpiece is vacuum-sucked by a suction pad, and after performing a predetermined operation,
Although the processed product will be released, when the processed product is released, the processed product remains attached to the suction pad and does not come off, or the vacuum state is released to prevent the delayed release timing of the processed product. A valve mechanism is installed, and compressed air is supplied at the same time as releasing the valve mechanism to ensure reliability of release.

Japanese Utility Model Laid-Open No. 60-125089 discloses a vacuum generating device provided with such a valve mechanism. The vacuum generating device disclosed in this publication is a device in which a valve mechanism is attached to an ejector pump provided with a nozzle for injecting compressed air, and the outer periphery of the nozzle injection port of the ejector pump and the inside of the suction pad are connected to each other. The inside of the adsorption pad is put into a vacuum state by communicating with each other and injecting compressed air.

The valve mechanism is operated by compressed air, stores compressed air in the air tank during operation, and shuts off the air tank and the supply source of compressed air during non-operation when the supply of compressed air is stopped. Then, the compressed air in the air tank is introduced into the adsorption pad to release the vacuum state. However, such a conventional vacuum generator has the technical problems described below.

[0005]

That is, in the vacuum generator disclosed in the above publication, a path for connecting the suction pad and the nozzle to each other and a path for connecting the valve mechanism portion and the suction pad to each other. When the compressed air in the air tank is introduced into the adsorption pad when releasing the vacuum state, the compressed air flows to the nozzle side and the efficiency of releasing the vacuum state in the adsorption pad decreases. However, there is a problem that the certainty of the processed product is deteriorated.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a vacuum generator capable of improving the efficiency of releasing a vacuum state. is there.

[0007]

In order to achieve the above object, the present invention provides a vacuum state in the adsorption pad by injecting compressed air from a nozzle and introduces compressed air into the adsorption pad. In a vacuum generator for releasing the vacuum state, a vacuum generator main body provided with the nozzle, and a valve mechanism part attached to the device main body, the valve mechanism part is an air for storing the compressed air. A tank, and an external connection hole that is connected for communication with the suction pad,
A spool valve element operated by the compressed air,
The spool valve body communicates between the injection port portion of the nozzle and the external connection hole during operation when the compressed air is supplied, and connects the supply source side of the compressed air and the air tank. When the communication is not performed and the compressed air supply is stopped, the communication between the injection port portion of the nozzle and the external connection hole and between the compressed air supply source side and the air tank is cut off. The external connection hole and the air tank are communicated with each other.

The valve mechanism section has a pair of first and second external connection holes that are connected to communicate with the suction pad, and the spool valve element is operated when the compressed air is supplied.
The injection port portion of the nozzle and the first external connection hole are communicated with each other, the compressed air supply source side is communicated with the air tank, and the supply of compressed air is stopped. During operation, the communication between the injection port portion of the nozzle and the first external connection hole and between the compressed air supply source and the air tank is cut off, so that the second external connection hole and the air tank. And can be configured to communicate with.

[0009]

According to the vacuum generator having the above structure, the valve mechanism portion attached to the main body of the apparatus is operated by the compressed air and the air tank for storing the compressed air, the external connection hole which is connected to the adsorption pad for communication. And a spool valve body that communicates between the injection port of the nozzle and the external connection hole during operation when compressed air is supplied, and also supplies the compressed air to the supply source side and the air tank. Since air is communicated with the air, the air in the adsorption pad is discharged along with the flow of the compressed air injected from the nozzle, the inside of the adsorption pad becomes a vacuum state, and the compressed air is stored in the air tank.

When the supply of the compressed air to the nozzle is stopped from this state, the spool valve element is deactivated, whereby the supply of the compressed air between the injection port portion of the nozzle and the external connection hole is performed. Since the communication between the source side and the air tank is blocked and the external connection hole and the air tank are communicated with each other, the compressed air in the air tank is introduced into the adsorption pad.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 and 2 show an embodiment of a vacuum generator according to the present invention. The vacuum generator shown in FIG. 1 has a nozzle 1 to which compressed air is supplied.
And a valve mechanism portion 3 attached to the apparatus main body 2.

The nozzle 1 provided in the apparatus main body 2 has a nozzle hole 1a penetrating in the axial direction thereof, an injection port portion 1b provided at the tip, an annular groove portion 1c circumferentially provided on the side surface, and the nozzle hole. Through-hole 1 for communicating between 1a and the annular groove 1c
and a compressed air supply source 5 is connected to the end of the nozzle hole 1a via a three-way switching solenoid valve 4. The main body 2 has a nozzle mounting hole 2a, a compressed air injection hole 2b communicating with the mounting hole 2a, and a first and a second end having one end opened to a side surface of the main body 2 and the other end communicating with the nozzle mounting hole 2a. Hole 2
c and 2d are formed at intervals in the axial direction. The nozzle 1 has a nozzle ring 2a with a seal ring 6 interposed.
In the fitted state of the nozzle 1, the nozzle hole 1a opens to the side portion of the main body 2 through the through hole 1d, the annular groove 1c, and the first hole portion 2c, and An annular space 7 is defined around the injection port 1b, and the annular space 7 is open to the side portion of the main body 2 via the second hole 2d.

The valve mechanism 3 has an air tank 8, first and second external connection holes 9 and 10, and a spool valve body 11. The valve mechanism portion 3 is integrally attached to a side portion of the vacuum apparatus body 2, and the first and second external connection holes 9 are provided on the surface opposite to the attachment surface at predetermined intervals along the axial direction. A main body portion 3a provided with 10, a valve hole 3b bored along the axial direction of the main body portion 3a, and a first annular communication hole 3c communicating between the first external connection hole 9 and the valve hole 3b. And the second
It has a second annular communication hole 3d that communicates between the external connection hole 10 and the valve hole 3b.

The body portion 3a is provided with first and second communicating holes 3e and 3f for communicating between the first and second hole portions 2c and 2d provided in the apparatus body 2 and the valve hole 3b, respectively. Has been drilled. The spool valve body 11 is formed in a substantially cylindrical shape, and its total length is shorter than the length of the valve hole 3b. The spool valve body 11 is slidably movable in the valve hole 3b by interposing seal packings 12 and 13 in the front and rear. It is installed. Spool valve body 1
The outer peripheral surface of No. 1 always communicates with the second communication hole 3f, and when moving forward (to the right in FIG. 1), allows communication between the second communication hole 3f and the first external connection hole 9. A spool groove portion 11a is provided around the spool groove portion 11a.

Further, the spool valve body 11 is provided with a spool hole portion 11c penetrating in the axial direction thereof and having an orifice 11b at the tip, and a cutout groove 11d is formed on the outer peripheral surface of the rear end thereof. There is. The valve hole 3b of the valve mechanism portion 3 is closed on the rear end side by an end plate 14 provided with a sealing material in a state where the spool valve body 11 is inserted therein, and has a substantially concave cross section on the front end side. Valve stopper 15
Is fitted and fixed. The valve stopper 15 is provided with a through hole 15a at the center thereof, and on the right end side of the valve stopper 15, the air tank 8 mounted in the valve hole 3b and the valve hole 3b.
It communicates with the inside of.

A suction pad 18 is communicatively connected to the first external connection hole 9 through a filter 17, and the second external connection hole 1
0 is directly connected to the suction pad 18. 1 and 2, the member designated by reference numeral 19 is a pressing plate that fixes the end plate 14 with screws. Next, the operation of the vacuum generator having the above configuration will be described. Figure 1
Shows the initial state before the operation of the vacuum generator of the present embodiment. In the state shown in this figure, since the work piece is not adsorbed to the adsorption pad 18, the air tank 8 includes the through hole 15a of the valve stopper 15, the valve hole 3b, the second annular communication hole 3d, and the second external connection hole 10. Is released to the atmosphere through.

When the suction pad 18 is brought into contact with the work piece and then the three-way switching solenoid valve 4 is energized to supply compressed air to the nozzle 1, the compressed air is supplied to the injection port 1 of the nozzle 1.
The nozzle hole 1a and the cutout groove 11d of the spool valve body 11 communicate with each other through the through hole 1d and the first communication hole 3e, and thus the cutout portion 11c. The spool valve element 11 moves to the right in FIG. 1 due to the pressure of the compressed air introduced therein.

FIG. 2 shows the spool valve body 11 thus constructed.
Shows a state in which it moves and abuts against the valve stopper 15. When the spool valve body 11 is actuated by compressed air, the annular space 7 on the outer periphery of the injection port 1b of the nozzle 1 and the first external connection hole 9 are shown. Through the second hole 2d, the second communication hole 3f, and the spool groove 11a, so that the air in the adsorption pad 18 is discharged along with the flow of the compressed air injected from the nozzle 1. The inside of the suction pad 18 is in a vacuum state, and the workpiece can be held by suction.

At this time, the second external connection hole 10 is closed at its side surface as the spool valve body 11 moves, and the spool valve body is provided between the compressed air supply source 5 side and the air tank 8. With the movement of 11, the notch groove 11d and the spool hole 11c communicate with each other, and compressed air is transferred to the spool valve hole 1
It is stored in the air tank 8 through 1c and the through hole 15a. In the course of this storage, since the orifice 11b is provided in the spool hole 11c, the pressure of the compressed air is increased by this orifice 11b, and the air tank 8
The internal pressure becomes almost the same as that of the compressed air supplied.

From this state, when the three-way switching solenoid valve 4 is de-energized and the supply of compressed air to the nozzle 1 is stopped, the pressure on the side of the first communication hole 3e decreases, and in FIG.
Since the pressure on the left side of the spool valve body 11 decreases, the spool valve body 11 is moved to the left side by being pushed by the compressed air pressure in the air tank 8, and returns to the state shown in FIG.
In this state, the annular space 7 of the nozzle 1 and the first external connection hole 9 are disconnected from each other, and the spool valve body 11 is closed.
The end portion of the contact portion abuts on the end plate 14, and the communication between the compressed air supply source 5 side and the air tank 8 is also cut off.

At the same time, since the second external connection hole 10 and the air tank 8 communicate with each other through the through hole 15a, the valve hole 3b, and the second annular communication hole 3d, the compressed air in the air tank 8 is compressed. Are introduced into the suction pad 18, whereby the processed product can be separated from the suction pad 18. Now, according to the vacuum generator configured as described above, with the first external connection hole 9 blocked, the second external connection hole 1
The adsorption pad 18 for adsorbing the compressed air in the air tank 8
Since it is introduced only into the inside, the problem that the compressed air flows to the nozzle 1 side, the efficiency of releasing the vacuum state in the adsorption pad 18 decreases, and the reliability of separation of the processed product deteriorates is avoided.

Further, in the apparatus of this embodiment, the spool valve element 11 is activated or deactivated by the difference between the compressed air pressure supplied to the nozzle 1 and the air pressure in the air tank 8, and the inside of the adsorption pad 18 is closed. Since the vacuum state or the vacuum release state is set, auxiliary equipment such as a timer is unnecessary. Further, in the apparatus of the present embodiment, when the air pressure stored in the air tank 8 becomes equal to the compressed air pressure supplied to the nozzle 1, the spool valve body 11 changes due to fluctuations in the supplied compressed air pressure. Although movement may occur, since the seal packings 12 and 13 are arranged in front of and behind the spool valve body 11, the movement of the spool valve body 11 is restricted by the frictional force of the seal packings 12 and 13. The vacuum state in the suction pad 18 can be stably maintained.

FIG. 3 shows another embodiment of the vacuum generator according to the present invention. The same or corresponding parts as those of the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Only the characteristic points will be described below.
In the example shown in the figure, the length of the spool valve body 11 is set as shown in FIG.
The second external connection hole and the second external connection hole are made shorter than those of the second embodiment.
A connection hole 20 in which the annular communication hole is removed and the external connection hole for obtaining a vacuum state and the external connection hole for releasing the vacuum state are integrated.
Is provided.

In the vacuum generator thus constructed, the same operational effect as the above embodiment can be obtained, and
In addition to this, the structure is simplified and the vacuum piping to the suction pad 18 is simplified.

[0025]

As described above in detail in the embodiments,
According to the vacuum generating apparatus of the present invention, auxiliary equipment such as a timer is not necessary, the efficiency of releasing the vacuum state in the suction pad is improved, and the reliability of the processed product is increased.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a vacuum generator according to the present invention.

FIG. 2 is a cross-sectional view of the spool valve body of FIG. 1 in an activated state.

FIG. 3 is a sectional view showing another embodiment of the vacuum generator according to the present invention.

[Explanation of symbols]

 1 Nozzle 1b Injection Port 2 Device Main Body 3 Valve Mechanism 3a Main Body 3b Valve Hole 5 Compressed Air Supply Source 7 Annular Space 8 Air Tank 9 First External Connection Hole 10 Second External Connection Hole 11 Spool Valve Body 15 Valve Stopper 18 Adsorption Pat 20 connection hole

Claims (2)

[Claims] 1. A vacuum generator for injecting compressed air from a nozzle to bring the suction pad into a vacuum state and introducing compressed air into the suction pad to release the vacuum state, wherein the nozzle is provided. And a valve mechanism section attached to the apparatus body, wherein the valve mechanism section has an air tank that stores the compressed air, and an external connection hole that is connected to communicate with the adsorption pad. A spool valve element operated by the compressed air, wherein the spool valve element communicates between the injection port portion of the nozzle and the external connection hole during operation when the compressed air is supplied. Connecting the supply side of the compressed air and the air tank, and between the injection port of the nozzle and the external connection hole when the supply of the compressed air is stopped and not operating, and A vacuum generator, characterized in that the communication between the compressed air supply source side and the air tank is cut off, and the external connection hole and the air tank are connected. 2. The valve mechanism section has a pair of first and second external connection holes that are connected to communicate with the suction pad, and the spool valve element is configured to operate when the compressed air is supplied. When the injection port portion of the nozzle and the first external connection hole are in communication with each other, the supply source of the compressed air is in communication with the air tank, and the supply of the compressed air is stopped during non-operation. , The communication between the injection port portion of the nozzle and the first external connection hole and between the compressed air supply source and the air tank is cut off to thereby connect the second external connection hole and the air tank. The vacuum generator according to claim 1, wherein the vacuum generators communicate with each other.