Ejector and vacuum generating device including the same

Patent metadata

Field	Value
Publication number	US-12435737-B2
Application number	US-202217664537-A
Country	US
Kind code	B2
Filing date	May 23, 2022
Priority date	Jun 18, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

An ejector includes an ejector body having an internal passage and a negative-pressure generating mechanism including a nozzle unit and a diffuser unit that generates a negative pressure by using compressed air ejected by the nozzle unit. The ejector body has a first attachment surface to which a valve body of a switching valve is attached and a second attachment surface to which a base body of the manifold base is attached. The first attachment surface has a first inflow port for supplying compressed air to the negative-pressure generating mechanism by being connected to a first output port of the switching valve, and this port communicates with the nozzle unit. The second attachment surface has a negative-pressure supply port for outputting a negative pressure to the outside by being connected to a negative-pressure inflow port of the manifold base, and this port communicates with the diffuser unit.

First claim

The invention claimed is:

1. An ejector that generates a negative pressure under an action of compressed air, the ejector comprising:
an ejector body in which an internal passage is formed; and
a negative-pressure generating mechanism including a nozzle unit that is connected to the internal passage and that ejects compressed air and a diffuser unit that generates a negative pressure by using compressed air ejected by the nozzle unit and that discharges compressed air to outside,
wherein the ejector body has a first attachment surface to which a valve body that serves as a body of a switching valve is fixedly attached and a second attachment surface to which a base body that serves as a body of a manifold base is fixedly attached,
wherein an inflow port for supplying compressed air to the negative-pressure generating mechanism by being connected to an output port that is formed in the valve body of the switching valve is formed in the first attachment surface of the ejector body, and the inflow port communicates with the nozzle unit through a positive-pressure supply passage that is included in the internal passage in the ejector body,
wherein a negative-pressure supply port for outputting a negative pressure, which is generated in the negative-pressure generating mechanism, to outside by being connected to a negative-pressure inflow port that is formed in the base body of the manifold base is formed in the second attachment surface of the ejector body, and the negative-pressure supply port communicates with the diffuser unit through a negative-pressure communication passage that is included in the internal passage in the ejector body,
wherein the inflow port of the first attachment surface includes a first inflow port and a second inflow port that are respectively connected to a first output port and a second output port of the output port that are formed in the valve body of the switching valve,
wherein one of the first inflow port and the second inflow port communicates with the nozzle unit through the internal passage, and
wherein another one of the first inflow port and the second inflow port communicates with the negative-pressure supply port through the internal passage.

2. The ejector according to claim 1 ,
wherein an ejector-side air-supply port for supplying compressed air to the switching valve by being connected to a switching-valve-side air-supply inflow port that is formed in the valve body of the switching valve is formed in the first attachment surface,
wherein an air-supply inflow port for receiving compressed air by being connected to an air-supply port that is formed in the base body of the manifold base is formed in the second attachment surface, and
wherein the ejector-side air-supply port and the air-supply inflow port communicate with each other through an air-supply communication passage that is included in the internal passage in the ejector body.

3. A vacuum generating device comprising:
the ejector according to claim 2 ;
the manifold base attached to the second attachment surface of the ejector; and
the switching valve attached to the first attachment surface of the ejector,
wherein the switching valve includes
the valve body having a valve hole that is formed in such a manner as to extend from a first end side to a second end side in an axial direction and a plurality of ports that are formed in such a manner as to communicate with the valve hole,
a spool that is accommodated in the valve hole of the valve body in such a manner as to be capable of freely sliding in the axial direction,
a first driving unit and a second driving unit that are arranged at two ends of the spool in the axial direction and that move the spool to a second-end-side switching position on the second end side in the axial direction and move the spool to a first-end-side switching position on the first end side in the axial direction, and
a spool moving mechanism unit that selectively moves the spool to a first-intermediate switching position and a second-intermediate switching position that are located between the first-end-side switching position and the second-end-side switching position and that are different from each other,

wherein the plurality of ports includes the first output port connected to the first inflow port of the ejector, the second output port connected to the second inflow port of the ejector, and the switching-valve-side air-supply inflow port to which compressed air is supplied by being connected to the ejector-side air-supply port formed in the first attachment surface of the ejector,
wherein the spool moving mechanism unit moves the spool that has moved to the first-end-side switching position to the first-intermediate switching position when the spool is released from being pressed by the second driving unit and moves the spool that has moved to the second-end-side switching position to the second-intermediate switching position when the spool is released from being pressed by the first driving unit,
wherein the first-intermediate switching position is in a communication state in which one of the first output port and the second output port that is in communication with the nozzle unit communicates with the switching-valve-side air-supply inflow port and in which the other ports are closed and do not communicate with each other, and
wherein the second-intermediate switching position is in a non-communication state in which all the plurality of ports are closed and do not communicate with each other.

4. The vacuum generating device according to claim 3 ,
wherein the spool includes a spring seat shaft that is coaxial with the spool,
wherein the spool moving mechanism unit includes a first spring seat and a second spring seat that are respectively arranged on a first end side and a second end side of the spring seat shaft in the axial direction in such a manner as to be freely movable in the axial direction and includes a compression spring that is provided between the first spring seat and the second spring seat,
wherein the spring seat shaft includes a pair of contact portions arranged at the two ends of the spring seat shaft in the axial direction such that the first and second spring seats are brought into contact with the contact portions, and the compression spring is disposed so as to be compressed when the first and second spring seats are in contact with the pair of contact portions,
wherein a pair of stopper portions with which the first and second spring seats are brought into contact are provided at two sides of the valve hole of the valve body in the axial direction with the spool moving mechanism unit interposed between the stopper portions, and wherein, when a length between the pair of contact portions in the axial direction is X, a length between the pair of stopper portions in the axial direction is Y, a stroke length of the spool by the first driving unit is S 1 , and a stroke length of the spool by the second driving unit is S 2 , relationships of X<Y and Y−X<S 1 , S 2 are satisfied.

5. The vacuum generating device according to claim 4 ,
wherein the valve hole has a spring accommodating chamber that extends in the axial direction and in which the spool moving mechanism unit is accommodated,
wherein the spring accommodating chamber has a pair of end walls that are formed at two ends of the spring accommodating chamber in the axial direction and each of which extends outward in a radial direction, and
wherein one of the pair of end walls includes the stopper portion with which the first spring seat is brought into contact, and another one of the pair of end walls includes the stopper portion with which the second spring seat is brought into contact.

6. The vacuum generating device according to claim 5 ,
wherein the pair of co

Assignees

• Smc Corp

Inventors

• Matsumura Kenichi

Classifications

• F04F5/52

  of evacuating pumps · CPC title

• F04F5/463

  with provisions for mixing · CPC title

• F04F5/46

  Arrangements of nozzles · CPC title

• F04F5/466

  with a plurality of nozzles arranged in parallel · CPC title

• F04F5/20 Primary

  for evacuating · CPC title