WO2009081467A1

WO2009081467A1 - Vacuum generator

Info

Publication number: WO2009081467A1
Application number: PCT/JP2007/074648
Authority: WO
Inventors: Koichi Morimoto
Original assignee: Koganei Corporation
Priority date: 2007-12-21
Filing date: 2007-12-21
Publication date: 2009-07-02

Abstract

A reception hole (17) is formed in the main block (11) of a vacuum generator (10), and an ejector element (19) is fitted into the reception hole (17). The ejector element (19) is formed by joining a nozzle (45), which has a base end part at which an inflow hole (47) is formed and a tip end part at which a diffusion hole (48) is formed, to a diffuser (46) in which a suction hole (53) is formed. A compressed air supplied from an air pressure source through a solenoid valve (22) for air supply control is jetted from the nozzle (45) toward a diffuser flow passage (55). A vacuum flow passage (56) communicating with the suction hole (53) is made in the state of negative pressure by the jet flow from the nozzle. The tip end of the ejector element (19) is projected from the end surface of the main block (11). When a silencer assembly (32) is separated from the main block (11), the tip end of the ejector element (19) projects to the outside.

Description

Vacuum generator

The present invention relates to a vacuum generator that jets compressed air from a nozzle to a diffuser to generate a negative pressure by a jet of compressed air.

A vacuum generator that supplies compressed air from a nozzle to a diffuser and sucks outside air into a suction hole formed in the diffuser to generate negative pressure is also called an ejector vacuum pump or simply an ejector. A vacuum is generated using the viscosity of Since this type of vacuum generator has no moving parts and does not require a vacuum tank, it can be miniaturized. For example, as described in Patent Document 1, an electronic component or the like is used as a transported object. It is used to supply negative pressure to the vacuum suction tool.

A vacuum generator used for sucking and transporting an object to be transported constitutes an apparatus main body by incorporating a nozzle having a diffusion hole for expanding compressed air and a diffuser having a suction hole communicating with the outside. Has a block. An air supply control solenoid valve for controlling the supply of compressed air to the nozzle is attached to this block. When a vacuum breaking electromagnetic valve is attached to this block, the detachment of the object to be conveyed from the vacuum suction tool can be performed quickly by supplying compressed air to the vacuum suction tool when releasing the suction of the object to be conveyed by the vacuum suction tool. It can be carried out.
JP 2002-103263 A

The nozzle has a diffusion hole for expanding compressed air at its tip, and the diffuser has a suction hole formed at its base end, and mixes the jet air ejected from the nozzle and the air flowing from the suction hole. Since the mixing portion is formed, the nozzle and the diffuser are manufactured separately, and these are combined and mounted on the block of the apparatus main body. Thus, in the conventional vacuum generator, the nozzle and the diffuser have a separate structure. The jet flow from the nozzle will flow in the diffuser flow path, and if foreign matter in the compressed air adheres to the diffuser flow path, the desired vacuum degree will not be obtained and the vacuum performance will deteriorate, so it is necessary to replace the diffuser. is there. An electromagnetic valve is attached to the outside of the block, and when the diffuser is replaced, the electromagnetic valve is removed from the block and the diffuser is separated from the nozzle.

In order to increase the degree of vacuum of the generated negative pressure air, it is necessary to increase the pressure and flow rate of the compressed air supplied to the nozzle. If so, the amount of air consumed can be reduced. Therefore, the inventors conducted various studies for improving the performance of the vacuum generator from the viewpoint of improving energy efficiency.

In the conventional vacuum generator, the nozzle and the diffuser are processed separately, and these have a separate structure. Therefore, in order to prevent air leakage from the gap between them, the sealing material is used as the nozzle. I try to put it between the blocks. As described above, when the sealing material is mounted, a slight clearance is provided in these fitting portions in consideration of the assembling property of the nozzle and the diffuser. For this reason, it was speculated that the nozzle vibrates or displaces in the radial direction although it is slightly with respect to the diffuser when air is blown out. Therefore, when the central axis of the nozzle and the central axis of the diffuser are integrated so that they coincide even when air is ejected, the compressed air supplied to the nozzle has the same pressure and flow rate as compared to the conventional separate structure. However, it has been found that the integrated structure can suppress the variation in the degree of vacuum obtained in each vacuum generator and stabilize the vacuum performance, thereby improving the performance of the vacuum generator. The present invention has been made by finding out the nozzle behavior when jets are discharged in this way.

An object of the present invention is to improve the performance of a vacuum generator.

A vacuum generator according to the present invention is a vacuum generator that generates negative pressure air by a jet of compressed air, and is formed in a circular shape that has a compressed air supply hole formed at one end thereof, communicates with the supply hole, and opens at the other end surface. A main block in which a housing hole is formed, and an air supply control electromagnetic valve that is attached to one end face of the main block and switches between a state in which compressed air from a compressed air supply source is supplied to the supply hole and a state in which supply is stopped An inflow hole communicating with the supply hole in the base end portion, a nozzle provided with a diffusion hole in the distal end portion for inflating compressed air toward the front end surface, and a vacuum channel formed in the main block. A diffuser flow path is provided that has a joining end portion in which a suction hole that communicates is formed, guides air flowing in from the diffusion hole and the suction hole toward the tip, and the nozzle is fastened to the joining end portion. Said A diffuser that forms an ejector element that fits into the housing hole integrally with the slip, and a muffler that is attached to the other end surface of the main block and silences the air that has passed through the diffuser and exhausts the air from the exhaust hole to the outside. And a built-in silencer assembly.

In the vacuum generator of the present invention, the silencer assembly is detachably connected to the other end surface of the main block, and a fitting hole is formed in the silencer assembly to fit the tip of the ejector element. When the silencer assembly is removed from the main block, the tip of the ejector element is exposed to the outside.

The vacuum generator of the present invention has the same outer diameter as the outer diameter of the diffuser and the base end of the nozzle, communicates the supply hole with the bottom surface of the supply hole, and pushes the ejector element into the bottom surface. The contact hole is mounted in the receiving hole.

The vacuum generator according to the present invention is for vacuum breaking, wherein the compressed air from a compressed air supply source is supplied to the vacuum channel to switch between a state in which the vacuum in the vacuum channel is broken and a state in which the supply of compressed air is stopped. A solenoid valve is attached to the surface of the main block.

According to the present invention, since the nozzle and the diffuser are integrated to form an ejector element, and the nozzle is coaxially joined to the diffuser, the compressed air from the nozzle is centered in the diffuser flow path of the diffuser. Is ejected without displacement. Thereby, the vacuum performance of the negative pressure air obtained compared with the case where a nozzle and a diffuser are made into a separate structure can be stabilized, and the performance of a vacuum generator can be improved.

Since the ejector element is formed by integrating the nozzle and diffuser, when the silencer assembly is removed from the main block, the tip of the ejector element protrudes from the end face of the main block, and the protruding end is held in the hand. The ejector element can be easily removed from the main block. Thereby, replacement | exchange of an ejector element can be performed easily.

It is a perspective view which shows the external appearance of the vacuum generator which is one embodiment of this invention. It is an expanded sectional view of FIG. (A) is an enlarged front view showing the ejector element disassembled into a nozzle and a diffuser, and (B) is a sectional view showing the ejector element formed by integrating the nozzle and the diffuser. It is a pneumatic circuit diagram which shows the flow of the air in the vacuum generator shown by FIG. It is a schematic sectional drawing which shows the vacuum generator shown as a comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an appearance of a vacuum generator according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of FIG.

As shown in FIG. 1, the vacuum generator 10 includes a main block 11 having a substantially rectangular parallelepiped shape, and the main block 11 is attached to the manifold block 12. Although a plurality of vacuum generators 10 are attached to the manifold block 12, only one vacuum generator 10 is shown in FIG. In order to attach the main block 11 to the manifold block 12, a screw member 14 protruding from the attachment surface 13 is provided on the main block 11, and a sheet-like gasket 15 is provided between the attachment surface 13 and the manifold block 12. It is designed to be incorporated.

As shown in FIG. 2, a supply hole 16 is formed at one end of the main block 11 so as to open to the end face, and an accommodation hole 17 communicating with the supply hole 16 is formed in the main block 11. The hole 17 is open to the other end surface of the main block 11. Both the supply hole 16 and the accommodation hole 17 have a circular cross section, the inner diameter of the supply hole 16 is set to be smaller than the inner diameter of the accommodation hole 17, and the bottom surface of the accommodation hole 17 is abutted in the radial direction. Surface 18 is formed. An ejector element 19 is inserted into the accommodation hole 17 so as to abut against the abutment surface 18.

An air supply control solenoid valve 22 is attached to one end surface of the main block 11 via an adapter 21. The adapter 21 is fixed to one end surface of the main block 11 by a plurality of screw members 23, and the air supply control electromagnetic valve 22 is fixed to the adapter 21 so as to cover the screw members 23 by the plurality of screw members 24.

The main block 11 is formed with a communication channel 26 that communicates with a common channel 25 formed in the manifold block 12, and the communication channel 26 supplies air via an air supply channel 27 formed in the adapter 21. It communicates with the air supply port 28 of the control solenoid valve 22. The adapter 21 is formed with an output flow path 31 for communicating the output port 29 of the air supply control electromagnetic valve 22 with the supply hole 16. A compressed air supply source such as a compressor (not shown) is connected to the common flow path 25, and the compressed air discharged from the compressed air supply source is supplied to the air supply flow path 27 via the communication flow path 26. The When a drive signal is sent to the coil of the air supply control electromagnetic valve 22, the air supply port 28 and the output port 29 are switched to the communication state by the valve body incorporated therein, and the compressed air is supplied to the air supply control electromagnetic valve. It is supplied to the ejector element 19 from the supply hole 16 through 22. On the other hand, when the supply of the drive signal to the coil is stopped, the communication between the air supply port 28 and the output port 29 is cut off, and the supply of compressed air to the supply hole 16 is stopped. Reference numeral 30 denotes a plug connected to the connector of the air supply control electromagnetic valve 22, and a drive signal for the coil of the air supply control electromagnetic valve 22 is supplied through a signal line connected to the plug.

A rectangular parallelepiped muffler assembly 32 is detachably attached to the other end surface of the main block 11. The silencer assembly 32 has a silencer block 32a, and a connection plate 35 is attached to an end surface of the silencer block 32a by a screw member 34 via a sheet-like gasket 33. A plurality of nuts 38 are incorporated in the main block 11, and the silencer assembly 32 is detachably attached to the main block 11 by a plurality of screw members 39 screwed to the respective nuts 38.

The coupling plate 35 is formed with a fitting hole 41 into which the tip of the ejector element 19 is fitted. When the silencer assembly 32 is attached to the main block 11, the ejector element 19 is inserted into the step 36 of the fitting hole 41. The front end surface abuts and is sandwiched between the stepped portion 36 and the abutting surface 18, and the ejector element 19 is positioned and fixed in the axial direction. Since the tip of the ejector element 19 protrudes from the end face of the main block 11, when the screw member 39 is loosened and the silencer assembly 32 is removed from the main block 11 together with the connecting plate 35, the tip of the ejector element 19 is moved to the main block. 11 is projected from the end face.

The muffler assembly 32 is formed with a muffler chamber 42 that communicates with the receiving hole 17, and the muffler chamber 42 is provided with a muffler 43 to mute the exhaust sound of the air discharged from the ejector element 19. In order to exhaust the exhausted air that has passed through the muffler 43 to the outside, the muffler block 32 is formed with an exhaust hole 44 that opens to the end face thereof.

The ejector element 19 is formed by the nozzle 45 and the diffuser 46 being coaxially joined together.

FIG. 3 (A) is an enlarged front view showing the ejector element disassembled into a nozzle and a diffuser, and FIG. 3 (B) is a cross-sectional view showing the ejector element formed by integrating the nozzle and the diffuser.

The nozzle 45 has a base end portion 45a having an outer diameter corresponding to the accommodation hole 17 and a tip portion 45b having a smaller diameter. An inflow hole 47 communicating with the supply hole 16 is formed in the base end portion 45a, and a diffusion hole 48 for inflating compressed air toward the distal end surface is formed in the distal end portion 45b so as to communicate with the inflow hole 47. The outer peripheral surface of 45b is a tapered surface 49 whose outer diameter becomes smaller toward the distal end surface.

The outer diameter of the diffuser 46 corresponds to the inner diameter of the accommodation hole 17, and one end portion is a joining end portion 46 a into which the tip portion 45 b of the nozzle 45 is press-fitted. A press-fit hole 51 is formed in the joint end portion 46a, and an annular groove 52 is formed on the outer peripheral surface. A plurality of suction holes 53 are formed in the joint end portion 46 a so as to communicate with the annular groove 52, and each suction hole 53 is formed between the inner surface of the joint end portion 46 a and the tapered surface 49 of the nozzle 45. It communicates with the mixing chamber 54. A diffuser channel 55 is formed in the diffuser 46 so as to communicate with the mixing chamber 54, and the diffuser channel 55 opens at the tip end surface of the diffuser 46.

The diffuser channel 55 has a straight portion 55a at the center in the longitudinal direction, a reduced diameter portion 55b for guiding the air flowing out from the mixing chamber 54 to the straight portion 55a, and a diffusion portion 55c for guiding the air flowing out from the straight portion 55a. In addition, the distal end side of the diffusion portion 55c is an expansion chamber 55d having a larger diameter.

As shown in FIG. 2, a vacuum channel 56 is formed in the main block 11 so as to communicate with the suction hole 53 of the diffuser 46, and the vacuum channel 56 is connected to a vacuum supply port 57 formed in the manifold block 12. Communicated. Therefore, the compressed air supplied from the common flow path 25 of the manifold block 12 to the inflow hole 47 of the nozzle 45 through the air supply control solenoid valve 22 expands in the diffusion hole 48 to increase the flow velocity. The pressure drops. As a result, the vacuum flow path 56 communicating with the mixing chamber 54 is in a negative pressure state, that is, a vacuum state, and a negative pressure is supplied to a vacuum device such as a vacuum suction tool connected thereto via the vacuum supply port 57. The air that has flowed into the diffuser channel 55 from the inflow hole 47 and the suction hole 53 through the mixing chamber 54 passes through the muffler 43 and is silenced, and then is discharged to the outside through the exhaust hole 44.

The nozzle 45 and the diffuser 46 are separately manufactured in a shape shown in FIG. 3 by machining using a metal material. The inner diameter of the press-fit hole 51 of the joint end 46a is formed to be slightly smaller than the outer diameter of the tip 45b of the nozzle 45, and as shown by the arrow in FIG. 3A, the press-fit hole 51 of the joint end 46a. When the tip 45b of the nozzle 45 is press-fitted in, the outer periphery of the tip 45b is elastically deformed radially inward, and the inner periphery of the joint end 46a is elastically deformed radially outward. Thereby, the nozzle 45 and the diffuser 46 are press-fitted and integrated with each other to form the ejector element 19. This press-fitting operation cannot be performed manually by an operator, but is performed by using a press-fitting press.

When the nozzle 45 is press-fitted into the diffuser 46 using the press-fitting press as described above, the nozzle 45 and a part of the diffuser 46 are elastically deformed and bonded to each other as described above. Air does not leak to the outside from the gap, and it is not necessary to install a sealing material between them. Moreover, since the nozzle 45 is integrated with the diffuser 46 to form the ejector element 19, mixing is performed when the compressed air from the inflow hole 47 and the air from the vacuum channel 56 are mixed in the mixing chamber 54. Even if a vortex is generated in the chamber 54 and the vibration caused by the generation and disappearance of the vortex propagates to the nozzle 45, the central axis of the nozzle 45 always coincides with the central axis of the diffuser 46. Generation of displacement is prevented. Thereby, even if the compressed air supplied to the nozzle 45 has the same pressure and flow rate, the vacuum generator having the ejector element 19 having an integrated structure in which the nozzle 45 and the diffuser 46 are integrated is separate from the conventional one. Rather than the structure, it is possible to stabilize the vacuum performance of the negative pressure air supplied to the vacuum equipment such as a vacuum suction tool via the vacuum supply port 57.

The nozzle 45 may be welded between the nozzle 45 and the press-fitting hole 51 of the diffuser 46 after the nozzle 45 is press-fitted into the joint end 46 a of the diffuser 46. In this case, the nozzle 45 and the diffuser 46 are integrated via the weld metal. Moreover, you may make it integrate both by an adhesive agent.

As shown in FIG. 3, two annular grooves 55e are formed on the outer peripheral surface of the diffuser 46, and

seal materials

59a and 59b are attached to the respective annular grooves 55e. As shown in FIG. 2, the sealing material 59 a prevents air leakage from between the sound deadening cover 35 and the diffuser 46, and the sealing material 59 b prevents air leakage from between the diffuser 46 and the accommodation hole 17. To do. Further, a sealing material 59 c is attached to the end face of the nozzle 45 to prevent air leakage from between the nozzle 45 and the accommodation hole 17.

A vacuum breaking electromagnetic valve 60 is attached by a screw member 61 to the surface 58 of the main block 11, that is, the surface opposite to the attachment surface 13. The main block 11 is formed with a branch flow path 62 communicating with the air supply flow path 27 of the adapter 21, and this branch flow path 62 communicates with the air supply port 63 of the vacuum break electromagnetic valve 60. The main block 11 is formed with an output flow path 65 for communicating the output port 64 of the vacuum breaking electromagnetic valve 60 and the vacuum flow path 56. When a drive signal is sent to the coil of the vacuum breaking electromagnetic valve 60, the air supply port 63 and the output port 64 are switched to the communication state by the valve body incorporated therein, and the compressed air passes through the vacuum breaking electromagnetic valve 60. Then, it is supplied from the vacuum channel 56 to the vacuum supply port 57. On the other hand, when the supply of the drive signal to the coil is stopped, the communication between the air supply port 63 and the output port 64 is cut off, and the supply of compressed air to the vacuum supply port 57 is stopped. Therefore, when the object to be conveyed is removed from the vacuum suction tool after the suction object has been sucked and transported by the vacuum suction tool, the supply of compressed air to the ejector element 19 is stopped and the vacuum suction port 57 is used for vacuum suction. When the compressed air for vacuum breakage is supplied to the tool, the conveyed object can be reliably removed from the suction tool. Reference numeral 66 denotes a plug connected to the connector of the vacuum breaking electromagnetic valve 60, and a drive signal for the coil of the vacuum breaking electromagnetic valve 60 is supplied via a signal line connected to the plug.

FIG. 4 is a pneumatic circuit showing the flow of air in the vacuum generator shown in FIG.

When supplying a negative pressure to the vacuum suction tool connected to the manifold block 12, a drive signal is sent to the coil of the air supply control electromagnetic valve 22, and the compressed air from the common flow path 25 is sent to the inflow hole of the ejector element 19. 47. Thereby, negative pressure air is supplied to the vacuum suction tool connected to the vacuum supply port 57, and the object to be transported is sucked and transported by the vacuum suction tool. When releasing the object to be conveyed by the vacuum suction tool, the supply of the drive signal to the air supply control electromagnetic valve 22 is stopped and the drive signal is supplied to the coil of the vacuum breaking electromagnetic valve 60. As a result, the supply of compressed air to the ejector element 19 is stopped, the compressed air for breaking the vacuum is supplied to the vacuum supply port 57, and the object to be conveyed is detached from the vacuum suction tool.

When the vacuum generator 10 is used for a long period of time and foreign matter adheres to the diffusion hole 48 of the nozzle 45, the vacuum generation capability will be reduced, and the ejector element 19 will be replaced. At this time, when the silencer assembly 32 is separated from the main block 11 by loosening the screw member 39, the tip of the ejector element 19 formed integrally with the nozzle 45 and the diffuser 46 protrudes from the end face of the main block 11. Therefore, the operator can easily take out the ejector element 19 from the main block 11 and replace it with a new one while holding the protruding tip portion in his hand.

FIG. 5 is a schematic cross-sectional view showing a vacuum generator as a comparative example, and members having the same functions as those in the above-described embodiment are denoted by the same reference numerals.

When the compressed air having the same pressure and the same flow rate was supplied to the vacuum generator 10a as a comparative example and the vacuum generator 10 of the present invention, the vacuum generator 10 of the present invention improved the stability of the vacuum performance. The reason for this is that, as shown in FIG. 5, when the diffuser 46 and the nozzle 45 are brought into contact with each other and a sealing material 71 is mounted between them and incorporated in the main block 11, the air discharged from the nozzle 45 and the suction holes It is considered that the nozzle 45 slightly vibrates in the radial direction with respect to the diffuser 46 due to the vortex generated when the air flowing in from the mixing chamber 53 is mixed in the mixing chamber 54. In the present invention, the nozzle 45 is press-fitted and fastened to the diffuser 46, and these are integrated to form the ejector element 19, so that the nozzle 45 is not vibrated or displaced, and the vacuum performance can be stabilized.

Further, in the vacuum generator 10a of the comparative example, the main block 11 is formed by the two

block pieces

11a and 11b. Therefore, when the foreign object adheres to the diffuser 46 and the diffuser 46 is replaced, the air supply control is performed. After the electromagnetic valve 22 is removed from the main block 11, the

block pieces

11a and 11b are separated from each other. Next, after the nozzle 45 is removed, the diffuser 46 that is separated from the nozzle 45 and remains in the block piece 11a is exchanged. For this exchange, it is necessary to take out the diffuser 46 from the block piece 11a. In contrast, in the vacuum generator 10 of the present invention, when the silencer assembly 32 is removed from the main block 11 when the ejector element 19 is exchanged, the tip of the ejector element 19 comes from the end face of the main block 11. Since it protrudes, the ejector element 19 can be easily removed, and the replacement work can be performed quickly and easily.

The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention. For example, although the vacuum generator 10 is mounted on the manifold block 12, it can be used alone.

The vacuum generator of the present invention is applied, for example, to suck and convey a workpiece in a production line for manufacturing a mass-produced product.

Claims

A vacuum generator that generates negative pressure air by a jet of compressed air,
A main block in which a compressed air supply hole is formed at one end and a circular accommodation hole is formed which communicates with the supply hole and opens on the other end surface;
An air supply control solenoid valve which is attached to one end surface of the main block and switches between a state where compressed air from a compressed air supply source is supplied to the supply hole and a state where supply is stopped;
An inflow hole communicating with the supply hole is provided in the base end, and a diffusion hole for inflating the compressed air toward the front end surface is provided in the front end; and
A diffuser flow path is provided which has a joint end portion formed with a suction hole communicating with a vacuum flow path formed in the main block and guides air flowing in from the diffusion hole and the suction hole toward the tip. And the diffuser which forms the ejector element which the above-mentioned nozzle is fastened to the above-mentioned joint end, and is united with the above-mentioned nozzle, and is fitted in the above-mentioned accommodation hole,
A vacuum generating apparatus comprising: a muffler block that is attached to the other end surface of the main block and that incorporates a muffler that muffles the air that has passed through the diffuser and exhausts the air from the exhaust hole to the outside.
2. The vacuum generator according to claim 1, wherein the muffler block is detachably connected to the other end surface of the main block, and a fitting hole is formed in the muffler block to fit a tip end portion of the ejector element. A vacuum generator, wherein the tip of the ejector element is exposed to the outside when the container assembly is removed from the main block.
2. The vacuum generator according to claim 1, wherein an outer diameter of the diffuser and the base end portion of the nozzle have the same outer diameter, the supply hole is communicated with a bottom surface of the supply hole, and the ejector element is connected to the bottom surface. The vacuum generator is mounted in the receiving hole by abutting against the housing.
2. The vacuum generating apparatus according to claim 1, wherein compressed air from a compressed air supply source is supplied to the vacuum channel to switch between a state in which the vacuum in the vacuum channel is broken and a state in which the supply of compressed air is stopped. A vacuum generating device, wherein a breaking electromagnetic valve is attached to a surface of the main block.