WO2016063499A1

WO2016063499A1 - Intermittent air generation device

Info

Publication number: WO2016063499A1
Application number: PCT/JP2015/005202
Authority: WO
Inventors: 浩二石毛; 丈司上間
Original assignee: クロダニューマティクス株式会社
Priority date: 2014-10-22
Filing date: 2015-10-14
Publication date: 2016-04-28
Also published as: TWI671484B; JPWO2016063499A1; TW201713886A; JP6557246B2

Abstract

[Problem] To provide an intermittent air generation device excelling in applicability using a simple structure, without the need for a pilot pressure-type on-off valve using a complicated structure. [Solution] A passage switching valve (20) with a three-port two-position pilot valve, which connects an inlet port (22) and an outlet port (24) and closes an exhaust port (26) when the pressure in a pilot chamber (84) is less than a prescribed value, and which closes the inlet port (22) and connects the outlet port (24) and the exhaust port (26) when the pressure in the pilot chamber (84) is equal to or greater than the prescribed value, is used. A throttle element (60) is provided between a first pilot passage (56A) and a second pilot passage (56B) which connect the pilot chamber (84) of the passage switching valve (20) to an air pressure source (10). The second pilot passage (56B) on the downstream side of the pilot chamber (84) or the throttle element (60) is connected to the exhaust port (26) of the passage switching valve (20) by an exhaust passage (58).

Description

Intermittent air generator

The present invention relates to an intermittent air generating device, and more particularly to an intermittent air generating device used for an air blowing device or the like.

Compressed air is frequently used in facilities such as factories. Compressed air is often used as a power source for driving pneumatic cylinders and turbines, but most of the compressed air used in factories and the like is consumed as air blowing air. Air for air blowing is widely used, for example, for blowing off foreign matters such as cutting powder removal, draining, drying, cooling, product conveyance, and the like.

In order to reduce the consumption of compressed air in air blow applications, intermittent injection of compressed air is employed. By intermittently injecting compressed air, the purpose of air blowing can be suitably achieved, and the consumption of compressed air can be reduced. In order to achieve the purpose of removing foreign matter, the instantaneous wind speed or air volume of compressed air is important for enhancing the foreign matter removal ability, but the average wind speed or air volume is known to be less important. Yes.

Also, air blow may be used for the purpose of transporting a collection of PET bottles. In such transport, when compressed air is blown continuously, a state in which PET bottles and the like compete and adjacent PET bottles mesh with each other appears, which may hinder the transport of PET bottles and the like. . Such a problem is solved when compressed air is blown intermittently in such conveyance.

The intermittent air blow can be realized by providing an electromagnetic on-off valve in the compressed air passage and supplying an on-off signal to the electromagnetic on-off valve from the outside. By using a programmable controller, timing and duty can be arbitrarily adjusted. However, electric wiring is required for the electromagnetic on-off valve, and a programmable controller is required to send an on-off signal to the electromagnetic on-off valve, which requires a great deal of cost and is newly introduced into existing equipment. With great difficulty.

In order to cope with this, it has been proposed that air blow (compressed air) be intermittently blown out by repeated opening and closing operations of the on-off valve caused by incorporating a feedback element into the pneumatic system of the air blowing device (for example, patents) Reference 1).

Japanese Patent Office Patent No. 3978659

However, the on-off valve shown in Patent Document 1 requires a plurality of valve bodies that operate in association with each other and a complicated pilot passage structure for repeated opening and closing operations, and is not practical. is there.

In view of the problems of the prior art, an object of the present invention is to eliminate the need for a pilot pressure type on-off valve having a complicated configuration, and to provide an economical intermittent air generator that is excellent in practicality by a simple configuration. Is to provide.

The intermittent air generator according to the present invention comprises a pilot chamber (84), an inlet port (22) connected to a pneumatic source (10), an outlet port (24), an exhaust port (26), and the pilot chamber ( 84) is less than a predetermined value, the inlet port (22) and the outlet port (24) are connected to close the exhaust port (26), and the pressure in the pilot chamber (84) is a predetermined value. When this is the case, the passage switching valve (20) having a valve body (74) that closes the inlet port (22) and connects the outlet port (24) and the exhaust port (26), and the pilot chamber A pilot passage (56A, 56B) for connecting (84) to the air pressure source (10), a throttle element (60) provided in the middle of the pilot passage (56A, 56B), and the pie Tsu Doo chamber (84) or the pilot passage (56A, 56B) of, and a exhaust passage connecting (58) to the exhaust port downstream (26) of the throttling element (60).

According to this configuration, a normally open type passage switching valve (20) having a simple structure with a two-position type pilot valve and a simple passage configuration of compressed air, such as an intermittent air blow excellent in practicality due to a simple configuration. Therefore, an intermittent air generator is obtained.

An intermittent air generator according to the present invention comprises a pilot chamber (184), an inlet port (122) connected to a pneumatic source (10), an outlet port (124), an exhaust port (126), and the pilot chamber ( When the pressure of 184) is less than a predetermined value, the inlet port (122) and the outlet port (124) are shut off and the exhaust port (126) is closed, and the pressure of the pilot chamber (184) is predetermined. A passage switching valve (120) having a valve body (174) for communicating the inlet port (122) and the outlet port (124) and opening the exhaust port (126) when the value is equal to or greater than the value; A pilot passage (156A, 156B) connecting a pilot chamber (184) to the air pressure source (10), and a pilot passage (156A, 156B) An exhaust for connecting the throttle element (160) provided therein and the pilot chamber (184) or the pilot passage (156A, 156B) downstream of the throttle element (160) to the exhaust port (126) And a passage (158).

According to this configuration, a normally closed type passage switching valve (120) having a simple structure with a two-position type pilot valve and a simple passage configuration of compressed air, such as an intermittent air blow excellent in practicality due to a simple configuration. Therefore, an intermittent air generator is obtained.

In the intermittent air generator according to the present invention, preferably, the throttle elements (60, 160) are in a fully closed state in which the pilot passages (56A, 156A) are selectively closed.

According to this configuration, the normally open type passage switching valve (20) can also perform continuous air blow by continuous injection, and the normally closed type passage switching valve (120) provides an injection stop state.

The intermittent air generator according to the present invention preferably has an on-off valve (200, 230) for selectively opening the pilot chamber (84, 184) to the atmosphere.

The intermittent air generating device according to the present invention preferably has on-off valves (220, 240) for opening and closing the pilot passages (56B, 156B).

In the intermittent air generating device according to the present invention, preferably, the throttle element (60, 160) is constituted by a variable throttle element (60, 160) capable of changing the throttle degree.

According to this configuration, the intermittent air blowing time can be variably set by changing the degree of restriction of the restriction elements (60, 160).

The intermittent air generator according to the present invention preferably further includes an air reservoir (90) connected to the pilot chamber (84, 184).

According to this configuration, the intermittent air blowing stop time can be variably set according to the internal volume of the air reservoir (90).

The intermittent air generator according to the present invention preferably further includes a throttle element (88) provided in the middle of the exhaust passage (58).

According to this configuration, the stop time of the intermittent air can be variably set according to the throttle degree of the throttle element (88).

In the intermittent air generating device according to the present invention, preferably, the passage switching valve (20) is operated by an equilibrium relationship between a load due to the pressure of the pilot chamber (84) and a spring load of the compression coil spring (82). A mechanism (110, 112) for variably installing the preload of the compression coil spring (82) is incorporated in the passage switching valve (20).

According to this configuration, the intermittent air blowing time and stop time can be variably set.

The intermittent air generator according to the present invention is preferably capable of changing the internal volume of the pilot chamber (184, 185).

According to this configuration, the intermittent air stop time can be variably set according to the internal volume of the pilot chamber (184, 185).

The intermittent air generator according to the present invention is preferably a valve in which at least a part of the throttle element (60), the pilot passage (56A, 56B) and the exhaust passage (58) accommodates the valve body (74). It is installed in the housing (28).

This configuration eliminates the need for external piping and allows further simplification.

According to the present invention, a pilot pressure type on-off valve having a complicated structure is not required, and an intermittent operation excellent in practicality by a simple structure by a simple structure of a passage switching valve and a simple passage structure of compressed air. An air generator is obtained.

The circuit diagram which shows the initial state of Embodiment 1 which applied the intermittent air generator by this invention as an air blower. The circuit diagram which shows the air blow stop state of the air blow apparatus by Embodiment 1. FIG. FIG. 3 is a circuit diagram showing an air blow-out state of the air blow device according to the first embodiment. Sectional drawing which shows the 1st position state of the specific structural example of the channel | path switching valve used for the air blow apparatus by Embodiment 1. FIG. Sectional drawing which similarly shows the 2nd position state. The circuit diagram which shows the initial state of Embodiment 2 which applied the intermittent air generator by this invention as an air blower. The circuit diagram which shows the air blow blowing state of the air blow apparatus by Embodiment 2. FIG. The circuit diagram which shows the air blow stop state of the air blow apparatus by Embodiment 2. FIG. Sectional drawing which shows the 1st position state of the specific structural example of the channel | path switching valve used for the air blower by Embodiment 2. FIG. Sectional drawing which similarly shows the 2nd position state. The circuit diagram which shows Embodiment 3 which applied the intermittent air generator by this invention as an air blower. Sectional drawing of the valve closing state which shows the specific structural example of the channel | path switching valve used for the air blower by Embodiment 3. FIG. Sectional drawing of the valve opening state which shows the specific structural example of the channel | path switching valve used for the air blower by Embodiment 3. FIG. The circuit diagram which shows Embodiment 4 which applied the intermittent air generator by this invention as an air blower. Sectional drawing of the valve opening state which shows the specific structural example of the channel | path switching valve used for the air blow apparatus by Embodiment 4. FIG. Sectional drawing of the valve closing state which shows the specific structural example of the channel | path switching valve used for the air blow apparatus by Embodiment 4. FIG. The circuit diagram which shows Embodiment 5 which applied the intermittent air generator by this invention as an air blower. The circuit diagram which shows Embodiment 6 which applied the intermittent air generator by this invention as an air blower. The figure similar to FIG. 1 which shows other embodiment which applied the intermittent air generator by this invention as an air blower. The figure similar to FIG. 4 which shows other embodiment which applied the intermittent air generator by this invention as an air blower.

Hereinafter, Embodiment 1 in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIGS.

1 to 3, the air pressure source 10 may include a compressor, a filter, a regulator, and an on-off valve (not shown) in a known manner. The compressed air output portion of the air pressure source 10 is connected to the inlet port 22 of the passage switching valve 20 by the inlet pipe 12.

The passage switching valve 20 is a three-port two-position pilot valve, and has the above-described inlet port 22, outlet port 24, and exhaust port 26. The outlet port 24 is connected to an air gun 100 for air blowing by an outlet pipe 14 made of a hose or the like. The air gun 100 has an air blow nozzle 102 for injecting compressed air to the outside, and a trigger valve 104 for opening and closing a flow path to the air blow nozzle 102. The trigger valve 104 is a normally closed on-off valve that is normally closed by a spring, and is opened when the trigger lever 106 provided on the air gun 100 is pulled by hand against the spring force.

The first pilot passage 56A is branched from the inlet pipe 12 and connected to the inlet end of the throttle element 60. The outlet end of the throttle element 60 is connected to the pilot chamber 84 of the passage switching valve 20 by the second pilot passage 56B. The pilot chamber 84 is connected to the exhaust port 26 by an exhaust passage 58.

Next, a specific configuration of the passage switching valve 20 will be described with reference to FIGS.

The passage switching valve 20 has a valve housing 28. A cylindrical chamber 30 is formed in the valve housing 28. The cylindrical chamber 30 has a closed first (right side) end and an open second (left side) end, in which a sleeve 36 is disposed. The sleeve 36 is configured by a cylindrical body having an outer diameter slightly smaller than the inner diameter of the cylindrical chamber 30, and forms a cylindrical main valve chamber 38 on the inner side. The sleeve 36 is sandwiched between an end wall 42 that defines the first end of the cylindrical chamber 30 and a plug 40 that is fitted into the opened second end of the cylindrical chamber 30, and is axially (see FIG. It is fixed to the valve housing 28 so that it cannot move in the left-right direction).

Three ports are formed in the sleeve 36 at intervals in the axial direction so as to correspond to the inlet port 22, the outlet port 24, and the exhaust port 26 described above with reference to FIG. . Each of the

ports

22, 24, 26 is formed by a plurality of through holes that are formed so as to penetrate the wall of the sleeve 36 in the radial direction and are spaced apart in the circumferential direction.

Four annular grooves are formed on the outer periphery of the sleeve 36, and an O-ring 46 is fitted in each annular groove. These O-rings 46 are in contact with the inner peripheral surface of the cylindrical chamber 30. This forms a seal between

adjacent ports

22, 24, 26. Further, the through holes constituting the

ports

22, 24, and 26 communicate with each other in common by an annular passage formed between adjacent O-rings 46 on the outer periphery of the sleeve 36.

The valve housing 28 communicates with the outlet port 24 through an inlet passage 52 provided in the valve housing 28 and communicates with the inlet port 22, and through an outlet passage 54 also provided in the valve housing 28. And an outlet opening 50 is provided. In the illustrated embodiment, the inlet opening 48 and the outlet opening 50 form a recess provided with an internal thread, but may also form a cylindrical extension.

The valve housing 28 is provided with a cylindrical needle valve hole 62 parallel to the cylindrical chamber 30. Needle valve hole 62 has an outer end that opens at the outer surface of valve housing 28, and an inner end that is narrowed and communicates with inlet opening 48 via first pilot passage 56A.

On the end surface of the plug 40 that contacts the opposite end of the sleeve 36, a pilot chamber 84 located in the center and

radial grooves

86A and 86B extending in the diametrical direction so as to communicate with the pilot chamber 84 are provided. Yes. The radial groove 86A communicates with the needle valve hole 62 via a second pilot passage 56B formed in the valve housing 28. The radial groove 86 B communicates with the exhaust port 26 through an exhaust passage 58 provided in the valve housing 28. Accordingly, the radial groove 86A forms an extension of the second pilot passage 56B, and the radial groove 86B forms an extension of the exhaust passage 58.

The needle valve body 64 is screwed into the needle valve hole 62. The inner end 64 A of the needle valve body 64 is tapered, and enters the constricted portion of the needle valve hole 62 (the opening end of the first pilot passage 56 A with respect to the needle valve hole 62) so that the inner end 64 A of the needle valve hole 62 By cooperating with the constriction portion, the throttle element 60 is configured. In this way, the throttle element 60 is incorporated in the valve housing 28 as a variable throttle valve.

The downstream end of the throttle element 60 is connected to the pilot chamber 84 via the second pilot passage 56B and the radial groove 86A. Therefore, a throttle element 60 for restricting the flow is provided between the two sections of the pilot passage. At the rear end of the needle valve body 64, the needle valve body 64 is screwed and retreated in the needle valve hole 62, and a tool engaging portion such as a hexagonal hole for adjusting the degree of throttling in the throttling element 60 is provided. (Not shown) is provided. An O-ring 72 for holding the needle valve body 64 in the needle valve hole 62 in an airtight state is provided at an intermediate portion of the needle valve body 64.

In the main valve chamber 38, a main valve body 74 having a cylindrical body is fitted so as to be movable in the axial direction. An annular recess 76 in the central portion in the axial direction and a pair of

lands

78 and 80 located on both sides in the axial direction of the annular recess 76 are formed on the outer periphery of the main valve body 74. As shown in FIG. 4, when the main valve body 74 is in the first position in contact with the left plug 40 in the figure, the inlet port 22 and the outlet port 24 are communicated with each other by the annular recess 76. The exhaust port 26 is closed by the land 78. On the other hand, when the main valve body 74 is in the second position in contact with the right end wall 42 in the drawing as shown in FIG. 26, the inlet port 22 is closed by the land 80.

A circular central recess 68 is provided at the right end of the main valve body 74, and a corresponding central recess 44 is provided in the end wall 42 of the opposing valve housing 28. A compression coil spring 82 is sandwiched between the

central recesses

68 and 44. The compression coil spring 82 is biased in the direction in which the main valve body 74 abuts against the opposing surface of the plug 40 (leftward). The valve housing 28 is provided with an air vent hole 45 in the central recess 44.

The pressure in the pilot chamber 84, that is, the pilot pressure, acts on the main valve body 74 as a force that urges the main valve body 74 to the second position side (right side) against the compression coil spring 82. As a result, the main valve body 74 operates by an equilibrium relationship between the load due to the pilot pressure and the spring load of the compression coil spring 82. When the pressure in the pilot chamber 84 is less than a predetermined value, the spring force of the compression coil spring 82 When the pressure in the pilot chamber 84 is equal to or higher than a predetermined value, the valve moves to the right against the spring force of the compression coil spring 82 and moves to the right. In the second position (see FIG. 5). Thus, the passage switching valve 20 forms a normally open type switching valve.

Next, the operation of the air blow device having the above configuration will be described.

FIG. 1 shows a state where the air pressure source 10 is stopped and compressed air is not supplied. Compressed air when the trigger valve 104 is closed and the main valve element 74 of the passage switching valve 20 is in the first position (see FIG. 4) (the pressure in the pilot chamber 84 is less than a predetermined value). Is started, the compressed air passes through the passage switching valve 20 and is supplied to the outlet pipe 14. At the same time, compressed air is supplied to the pilot chamber 84 through the first pilot passage 56A, the throttle element 60, the second pilot passage 56B, etc., so that the pressure in the pilot chamber 84 is not increased instantaneously. It gradually rises under the action.

When the pressure in the pilot chamber 84 exceeds a predetermined value, the main valve body 74 is displaced to the second position (see FIG. 5) against the spring force of the compression coil spring 82, as shown in FIG. Then, the outlet port 24 communicates with the exhaust port 26 and the inlet port 22 is closed.

When the trigger valve 104 is opened by operating the trigger lever 106 in this state, the state shown in FIG. 2 is reached, and the compressed air in the pilot chamber 84 is supplied to the exhaust passage 58, the passage switching valve 20, and the outlet pipe 14. The air is discharged from the air blow nozzle 102 through the trigger valve 104. However, due to the action of the throttle element 60, the amount of air discharged from the air blow nozzle 102 at this time is such that the main valve body 74 of the passage switching valve 20 is in the first position (see FIG. 4). It is a little compared with the jet flow rate.

As the compressed air in the pilot chamber 84 is exhausted from the air blow nozzle 102 through the exhaust passage 58, the passage switching valve 20, the outlet pipe 14, and the trigger valve 104, the pressure in the pilot chamber 84 decreases. As a result, when the pressure in the pilot chamber 84 becomes less than a predetermined value, the main valve body 74 of the passage switching valve 20 returns to the first position by the spring force of the compression coil spring 82, and the outlet port 24 becomes the inlet port 22. As a result, the exhaust port 26 is closed and the state shown in FIG. 3 is obtained.

Thereby, the compressed air from the air pressure source 10 passes through the passage switching valve 20 and the trigger valve 104 and is ejected from the air blow nozzle 102 to the outside with a large flow rate. At this time, since the exhaust port 26 is closed, a part of the compressed air is supplied from the inlet opening 48 to the pilot chamber 84 through the first pilot passage 56A, the throttle element 60, the second pilot passage 56B, and the like. Then, the pressure in the pilot chamber 84 gradually increases under the action of the throttle element 60. When the pressure in the pilot chamber 84 becomes a predetermined value or more, the main valve element 74 is positioned at the second position again, and the outlet port 24 communicates with the exhaust port 26 as shown in FIG. Is blocked, the injection of a large flow rate of compressed air from the air blow nozzle 102 stops, and the compressed air in the pilot chamber 84 again passes through the exhaust passage 58, the passage switching valve 20, the outlet conduit 14, and the trigger valve 104. Then, the air starts to be discharged from the air blow nozzle 102.

Thereafter, the pressure drop and rise in the pilot chamber 84 are repeated under the switching action of the passage switching valve 20, whereby the compressed air is repeatedly ejected and stopped, and intermittent air blow is performed. The blow time of the air blow is determined by the throttle degree of the throttle element 60 and the internal volume of the pilot chamber 84 that determine the rate of increase of the pressure in the pilot chamber 84. The higher the throttle degree of the throttle element 60, the larger the internal volume of the pilot chamber 84. The longer the blow time of the air blow becomes. The air blow stop time is determined by the internal volume of the pilot chamber 84. The larger the internal volume of the pilot chamber 84, the longer it takes to discharge the compressed air from the pilot chamber 84 until the pressure in the pilot chamber 84 becomes less than a predetermined value. Therefore, the air blow stop time becomes longer as the inner volume of the pilot chamber 84 is larger. The blow time and stop time of the air blow are also determined by the preload and spring constant of the compression coil spring 82 of the passage switching valve 20, and the larger the preload and spring constant of the compression coil spring 82, the longer the blow time. Stop time is shortened. In this way, the blow time, stop time, and duty ratio of the air blow are variably set by changing the throttle degree of the throttle element 60, the internal volume of the pilot chamber 84, the spring force of the compression coil spring 82, and the spring constant. Can do.

As described above, according to the first embodiment, there is no need for a pilot pressure type on-off valve having a complicated configuration, and a simple structure of the passage switching valve 20 using a 3-port 2-position type pilot valve and the compressed air With the simple passage configuration, an intermittent air generation device having a simple configuration and excellent in practicality can be obtained. Further, since the throttle element 60, the first pilot passage 56A, the second pilot passage 56B, and the exhaust passage 58 are provided in the valve housing 28, external piping for them is not required, and the number of parts is reduced. This further simplifies the process.

The throttle element 60 has a structure in which the inner end 64 A of the needle valve body 64 comes into contact with a portion defining the narrowed portion of the needle valve hole 62 so that the first pilot passage 56 A can be fully closed. be able to.

When the first pilot passage 56A is closed by the throttle element 60, compressed air is not supplied from the inlet opening 48 to the pilot chamber 84, so that the pressure in the pilot chamber 84 is maintained below a predetermined value. Thereby, the state in which the main valve body 74 of the passage switching valve 20 is located at the first position (see FIG. 4) is maintained.

In this case, that is, when the throttle element 60 is set to the fully closed state, the compressed air from the air pressure source 10 passes through the passage switching valve 20 and the trigger valve 104 and continuously from the air blow nozzle 102 with a large flow rate. Erupted.

This makes it possible to easily switch the air blow mode between intermittent air blow and continuous air blow simply by opening and closing the throttle element 60.

Next, a second embodiment in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIGS. 6 to 8, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals as those in FIGS. 1 to 3.

6 to 8, the air pressure source 10 may include a compressor, a filter, a regulator, and an on-off valve (not shown) in a known manner. The compressed air output of the air pressure source 10 is connected to the inlet port 122 of the passage switching valve 120 by the inlet pipe 12.

The passage switching valve 120 is a 4-port 2-position pilot valve, and has the above-described inlet port 122, first outlet port 124, exhaust port 126, and second outlet port 127.

The first outlet port 124 is connected to an air gun 100 for air blowing by an outlet pipe 14 made of a hose or the like. The air gun 100 has an air blow nozzle 102 for injecting compressed air to the outside, and a trigger valve 104 for opening and closing a flow path to the air blow nozzle 102. The trigger valve 104 is a normally closed on-off valve that is normally closed by a spring, and is opened when the trigger lever 106 provided on the air gun 100 is pulled by hand against the spring force.

The second outlet port 127 is connected to the outlet pipeline 14 by an outlet passage 129. A throttle element 131 is provided in the middle of the outlet passage 129.

The first pilot passage 156A branches from the inlet pipe 12 and is connected to the inlet end of the throttle element 160. The outlet end of the throttle element 160 is connected to the pilot chamber 184 of the passage switching valve 120 via the second pilot passage 156B. The pilot chamber 184 is connected to the exhaust port 126 via the exhaust passage 158.

Next, a specific configuration of the passage switching valve 120 will be described with reference to FIGS.

The passage switching valve 120 has a valve housing 128. A cylindrical chamber 130 is formed in the valve housing 128. The cylindrical chamber 130 has a closed first (right side) end and an open second (left side) end, and a sleeve 136 is disposed therein. The sleeve 136 is formed of a cylindrical body having an outer diameter slightly smaller than the inner diameter of the cylindrical chamber 130, and forms a cylindrical main valve chamber 138 on the inner side. The sleeve 136 is sandwiched between an end wall 142 that defines a first end of the cylindrical chamber 130, a plug 140 fitted into the opened second end of the cylindrical chamber 130, and a washer-shaped rubber packing 141. Thus, the valve housing 128 is fixed so that it cannot move in the axial direction (left and right in the figure).

The sleeve 136 has three ports in the axial direction so as to correspond to the inlet port 122, the first outlet port 124, and the second outlet port 127 described above with reference to FIG. Is formed. Each

port

122, 124, 127 is formed by a plurality of through holes that are formed so as to penetrate the wall of the sleeve 136 in the radial direction and are spaced apart in the circumferential direction. Further, an opening for a pilot chamber 184 described later of the sleeve 136 forms an exhaust port 126.

Three annular grooves are formed on the outer periphery of the sleeve 136, and an O-ring 146 is fitted in each annular groove. These O-rings 146 are in contact with the inner peripheral surface of the cylindrical chamber 130. This forms a seal between

adjacent ports

122, 124, 127. Further, the through holes constituting each

port

122, 124, 127 communicate with each other in common by an annular passage formed between adjacent O-rings 146 on the outer periphery of the sleeve 136.

The valve housing 128 has an inlet opening 148 communicating with the inlet port 122 via an inlet passage 152 provided in the valve housing 128, and a first outlet port 124 via an outlet passage 154 also provided in the valve housing 128. And an outlet opening 150 that communicates with the second outlet port 127 via the outlet passage 129. The outlet passage 129 has a passage sectional area smaller than that of the outlet passage 154 and the like, so that the outlet passage 129 itself forms the throttle element 131 in FIGS.

The valve housing 128 is provided with a cylindrical needle valve hole 162 parallel to the cylindrical chamber 130. Needle valve hole 162 has an outer end that opens at the outer surface of valve housing 128, and an inner end that is narrowed and communicates with inlet opening 148 via first pilot passage 156A.

The needle valve body 164 is screwed into the needle valve hole 162. The inner end 164A of the needle valve body 164 is tapered, and enters the constricted portion of the needle valve hole 162 (the opening end of the first pilot passage 156A with respect to the needle valve hole 162) to the inner end of the needle valve hole 162. By cooperating with the constriction portion, the throttle element 160 is configured. In this way, the throttle element 160 is incorporated in the valve housing 128 as a variable throttle valve.

The end surface of the plug 140 that contacts the opposite end of the sleeve 136 is provided with a pilot chamber 184 located in the center and a radial groove 186 that extends in the diametrical direction so as to communicate with the pilot chamber 184. The radial groove 186 communicates with the needle valve hole 162 via a second pilot passage 156 B formed in the valve housing 128.

The downstream end of the throttle element 160 is connected to the pilot chamber 184 via the second pilot passage 156B and the radial groove 186. Therefore, a throttle element 160 for restricting the flow is provided between the two sections of the pilot passage. At the rear end of the needle valve body 164, a tool engagement portion such as a hexagonal hole for adjusting the degree of throttling in the throttling element 160 by screwing and screwing the needle valve body 164 into the needle valve hole 162. (Not shown) is provided. An O-ring 172 for holding the needle valve body 64 in the needle valve hole 62 in an airtight state is provided at an intermediate portion of the needle valve body 164.

A hole 192 is formed in the plug 140. Hole 192 has an outer end that opens at the outer surface of valve housing 128 and an inner end that opens into pilot chamber 184. A movable plug 193 is screwed into the hole 192. The movable plug 193 closes the outer end of the hole 192 and defines an extended pilot chamber 185 on the inner end side. The movable plug 193 is provided with a tool engaging portion 194 such as a hexagonal hole for screwing and retracting the movable plug 193 in the hole 192 to increase or decrease the internal volume of the expansion pilot chamber 185. An O-ring 195 for holding the movable plug 193 in the hole 192 in an airtight state is provided on the distal end side of the movable plug 193.

In the main valve chamber 138, a main valve body 174 forming a cylindrical body is fitted so as to be movable in the axial direction. An annular recess 176 at the center in the axial direction and a pair of

lands

178 and 180 located on both sides in the axial direction of the annular recess 176 are formed on the outer periphery of the main valve body 174. As shown in FIG. 9, when the end surface 175 of the main valve body 174 is in the first position in contact with the left rubber packing 141 in the drawing, the land 178 closes the inlet port 122 and The communication between the exhaust port 126 and the second outlet port 127 is blocked by 180. Note that blocking communication between the exhaust port 126 and the second outlet port 127 is the same as closing the exhaust port 126. On the other hand, when the main valve body 174 is in the second position in contact with the right end wall 142 in the drawing as shown in FIG. The first outlet port 124 is communicated, and the exhaust port 126 is opened to allow the pilot chamber 184 and the second outlet port 127 to communicate.

A circular center recess 168 is provided at the right end of the main valve body 174, and a corresponding center recess 144 is provided in the end wall 142 of the opposing valve housing 128. A compression coil spring 182 is sandwiched between the

central recesses

168 and 144. The compression coil spring 182 urges the main valve body 174 in a direction in which the main valve body 174 abuts against the opposing surface of the rubber packing 141 (to the left). The valve housing 128 is formed with an air vent hole 145 in the central recess 144.

The pressure in the pilot chamber 184, that is, the pilot pressure, acts on the main valve body 174 as a force that biases the main valve body 174 against the compression coil spring 182 to the second position side (right side). As a result, the main valve body 174 operates according to an equilibrium relationship between the load due to the pilot pressure and the spring load of the compression coil spring 182, and when the pressure in the pilot chamber 184 is less than a predetermined value, the spring force of the compression coil spring 182 causes When the pressure in the pilot chamber 184 is equal to or higher than a predetermined value, the valve moves to the right against the spring force of the compression coil spring 182 and moves to the right. The second position (see FIG. 10). Thus, the passage switching valve 120 forms a normally closed switching valve. In the passage switching valve 120, the pilot chamber 184 communicates directly with the second outlet port 127 without requiring a special passage by the main valve chamber 138, so that the exhaust passage 158 in FIGS. 6 and 7 does not exist. .

FIG. 6 shows a state where the air pressure source 10 is stopped and compressed air is not supplied. Compressed air when the trigger valve 104 is closed and the main valve body 174 of the passage switching valve 120 is in the first position (see FIG. 9) (the pressure in the pilot chamber 184 is less than a predetermined value). Is started, the inlet port 122 is closed, so that the flow of compressed air that flows from the inlet port 122 to the outlet pipe 14 is blocked by the passage switching valve 120. At this time, the exhaust port 126 is closed, and the flow of compressed air that flows from the exhaust port 126 to the outlet passage 129 is also blocked by the passage switching valve 120. Therefore, the first pilot passage 156A, the throttle element 160, the pressure in the pilot chamber 184 gradually rises under the action of the throttle element 160 by the compressed air supplied to the pilot chamber 184 through the second pilot passage 156B and the like.

When the pressure in the pilot chamber 184 exceeds a predetermined value, the main valve body 174 is displaced to the second position against the spring force of the compression coil spring 182 as shown in FIG. And the first outlet port 124 communicate with each other, and the exhaust port 126 and the second outlet port 127 communicate with each other.

In this state, when the trigger valve 104 is opened by operating the trigger lever 106, the state shown in FIG. 7 is reached, and the compressed air from the air pressure source 10 passes through the passage switching valve 120 and the trigger valve 104, The air blow nozzle 102 is ejected with a large flow rate to the outside. At the same time, the compressed air in the pilot chamber 184 including the expanded pilot chamber 185 is discharged from the air blow nozzle 102 through the passage switching valve 120, the outlet passage 129, the outlet pipe 14, and the trigger valve 104. The compressed air is gradually discharged by the action of the throttle element 131.

As the compressed air in the pilot chamber 184 is discharged to the outside, the pressure in the pilot chamber 184 decreases. As a result, when the pressure in the pilot chamber 184 becomes less than a predetermined value, the main valve body 174 of the passage switching valve 120 is in the state shown in FIG. 8 by the spring force of the compression coil spring 182.

Thereby, the ejection of a large flow rate of compressed air from the air blow nozzle 102 stops, and the pressure in the pilot chamber 184 gradually rises again under the action of the throttle element 160. Thereafter, when the pressure in the pilot chamber 184 again becomes a predetermined value or more, the main valve body 174 is displaced to the second position against the spring force of the compression coil spring 182 as shown in FIG. The inlet port 122 and the first outlet port 124 communicate with each other, and the exhaust port 126 and the second outlet port 127 communicate with each other.

Thereafter, the pressure drop and rise in the pilot chamber 184 are repeated under the switching action of the passage switching valve 120, whereby the compressed air is repeatedly ejected and stopped, and intermittent air blow is performed. The blow time of the air blow is determined by the throttle degree of the

throttle elements

160 and 131 that determine the rate of increase in the pressure of the pilot chamber 184 and the internal volume of the pilot chamber 184. The higher the throttle degree of the

throttle elements

160 and 131, the more the pilot chamber 184 The larger the internal volume, the longer the air blow-out time. The air blow stop time is determined by the internal volume of the pilot chamber 184. The larger the internal volume of the pilot chamber 184, the longer it takes to discharge the compressed air in the pilot chamber 184 until the pressure in the pilot chamber 184 becomes less than a predetermined value. Therefore, the larger the internal volume of the pilot chamber 184, the longer the air blow stop time. The blow time and stop time of the air blow are also determined by the preload and spring constant of the compression coil spring 182 of the passage switching valve 120. The larger the preload and spring constant of the compression coil spring 182, the longer the blow time. Stop time is shortened. In this way, the blow time, stop time, and duty ratio of the air blow are variably set by changing the throttle degree of the

throttle elements

160 and 131, the internal volume of the pilot chamber 184, the spring force of the compression coil spring 182 and the spring constant. can do. The internal volume of the pilot chamber 184 can be variably set by changing the internal volume of the extended pilot chamber 185 by the movable plug 193.

As described above, according to the second embodiment, there is no need for a pilot pressure type on-off valve having a complicated configuration, and a simple structure of the passage switching valve 120 and the compressed air of the 4-port 2-position type pilot valve is used. With the simple passage configuration, an intermittent air generation device having a simple configuration and excellent in practicality can be obtained. In addition, since the

throttle elements

160 and 131, the first pilot passage 156A, and the second pilot passage 156B are provided in the valve housing 128, external piping for them becomes unnecessary, and the number of parts is reduced. In this way, further simplification is achieved.

The throttle element 160 has a structure in which the inner end 164A of the needle valve body 164 comes into contact with a portion that defines the narrowed portion of the needle valve hole 162 so that the first pilot passage 156A can be fully closed. be able to.

When the first pilot passage 156A is closed by the throttle element 160, compressed air is not supplied from the inlet opening 148 to the pilot chamber 184, so that the pressure in the pilot chamber 184 becomes less than a predetermined value and the state less than the predetermined value is maintained. The Thereby, the state in which the main valve body 174 of the passage switching valve 120 is located at the first position (see FIG. 9), that is, the valve closing state is maintained.

In this case, that is, when the throttle element 160 is set to the fully closed state, a stopped state in which the compressed air from the air pressure source 10 is not ejected from the air blow nozzle 102 is obtained.

Next, a third embodiment in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIGS. In FIG. 11, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted. 12 and FIG. 13, parts corresponding to those in FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and description thereof is omitted.

In the third embodiment, the plug 40 of the normally open type passage switching valve 20 in the first embodiment is provided with an on-off valve 200 that selectively opens the pilot chamber 84 to the atmosphere. The on-off valve 200 is disposed in a valve chamber 202 formed in the plug 40, and is a columnar shape that can move between the valve closing position shown in FIG. 12 and the valve opening position shown in FIG. The valve body 204 is provided.

The valve body 204 is restricted to move in the axial direction between the valve closing position and the valve opening position by the engagement with the stopper pin 206, and the O-ring 208 is inside the valve chamber 202 at the valve closing position. By making contact with the peripheral surface, the sealing performance of the pilot chamber 84 is maintained, and at the valve opening position, the O-ring 208 is separated from the inner peripheral surface of the valve chamber 202 by contact, thereby making the pilot chamber 84 the outer peripheral surface of the valve body 204. The pilot chamber 84 is opened to the atmosphere by a gap 210 between the valve chamber 202 and the inner peripheral surface of the valve chamber 202. The flow rate of compressed air discharged from the pilot chamber 84 by the on-off valve 200 is larger than the flow rate of compressed air in the throttle element 60.

The valve body 204 is urged toward the valve closing position by the spring force of the compression coil spring 212, and against the spring force of the compression coil spring 212 by pressing a button 214 provided on the outer end. Located in the open position. The valve body 204 may be connected to an alternate mechanism (not shown) that selectively self-holds at either the valve closing position or the valve opening position.

In the third embodiment, when the valve body 204 is in the closed position shown in FIG. 12 and the pilot chamber 84 is not open to the atmosphere in the on-off valve 200, intermittent air blow is performed as in the first embodiment. Is called.

When the valve body 204 is in the valve open position shown in FIG. 13 and the pilot chamber 84 is opened to the atmosphere in the on-off valve 200, the compressed air that has entered the pilot chamber 84 from the inlet opening 48 enters the atmosphere from the on-off valve 200. Therefore, the pressure in the pilot chamber 84 does not rise above a predetermined value, and the main valve body 74 is maintained in the first position.

In this case, continuous air blow is performed in which compressed air from the air pressure source 10 passes through the passage switching valve 20 and the trigger valve 104 and is continuously ejected from the air blow nozzle 102 with a large flow rate. Thereby, the air blow mode can be easily switched between the intermittent air blow and the continuous air blow only by opening and closing the on-off valve 200 incorporated in the passage switching valve 20.

During continuous air blowing, there is a loss that compressed air is discharged into the atmosphere from the on-off valve 200. However, since the flow rate of compressed air flowing from the inlet opening 48 to the pilot chamber 84 is limited by the throttle element 60, the compressed air The amount of loss is small.

Next, a fourth embodiment in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIGS. 14, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted. 15 and FIG. 16, parts corresponding to those in FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and description thereof is omitted.

In the fourth embodiment, the passage switching valve 20 in the first embodiment is provided with an on-off valve 220 for connecting and blocking the second pilot passage 56B. The on-off valve 220 is disposed in a valve chamber 222 formed in the valve housing 28, and is a spool that is movable between a valve opening position shown in FIG. 15 and a valve closing position shown in FIG. It has a valve body 224. The spool valve body 224 has a communication hole 225, establishes communication of the second pilot passage 56B by the communication hole 225 at the valve opening position, and blocks communication of the second pilot passage 56B at the valve closing position. The spool valve body 224 is positioned at the valve opening position or the valve closing position by manual operation of the operation element 226 provided at the outer end, and is selectively held at any position by an alternate mechanism (not shown). Note that the on-off valve 220 formed by the spool valve body 224 is provided with a seal 227 for preventing air leakage.

In the fourth embodiment, when the spool valve body 224 is in the open position shown in FIG. 15 and the second pilot passage 56B is in communication, compressed air is supplied from the inlet opening 48 to the pilot chamber 84, and the operation is performed. Similar to the first mode, intermittent air blow is performed.

When the spool valve body 224 is located at the closed position shown in FIG. 16 and the communication of the second pilot passage 56B is blocked, compressed air is not supplied from the inlet opening 48 to the pilot chamber 84. The pressure of 84 does not rise above a predetermined value, and the main valve body 74 is maintained in the first position.

In this case, continuous air blow is performed in which compressed air from the air pressure source 10 passes through the passage switching valve 20 and the trigger valve 104 and is continuously ejected from the air blow nozzle 102 with a large flow rate. Thereby, the air blow mode can be easily switched between the intermittent air blow and the continuous air blow simply by opening and closing the on-off valve 220 incorporated in the passage switching valve 20.

The on-off valve 220 may open and close the first pilot passage 56A on the upstream side of the throttle element 60.

Next, a fifth embodiment in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIG. In FIG. 17, parts corresponding to those in FIG. 6 are denoted by the same reference numerals as those in FIG.

In the fifth embodiment, an on-off valve 230 that selectively opens the pilot chamber 184 of the normally closed passage switching valve 120 in the second embodiment to the atmosphere is provided. The on-off valve 230 may be equivalent to the on-off valve 200 of the third embodiment.

When the pilot chamber 184 is opened to the atmosphere by the on-off valve 230, the pressure in the pilot chamber 184 does not exceed a predetermined value. As a result, the passage switching valve 120 is maintained in a closed state, and the compressed air from the air pressure source 10 is stopped from being ejected from the air blow nozzle 102 to the outside.

Next, a sixth embodiment in which the intermittent air generating device according to the present invention is applied as an air blowing device will be described with reference to FIG. In FIG. 18, parts corresponding to those in FIG. 6 are denoted by the same reference numerals as those in FIG.

In the sixth embodiment, an on-off valve 240 is provided to communicate and block the second pilot passage 156B of the normally closed passage switching valve 120 in the second embodiment. The on-off valve 240 may be equivalent to the on-off valve 220 of the fourth embodiment.

When the second pilot passage 156B is blocked by the on-off valve 240, the compressed air in the pilot chamber 184 is not supplied, so the pressure in the pilot chamber 184 does not exceed a predetermined value. As a result, the passage switching valve 120 is maintained in a closed state, and the compressed air from the air pressure source 10 is stopped from being ejected from the air blow nozzle 102 to the outside.

The on-off valve 240 may be provided in the first pilot passage 156A.

Although the present invention has been described above with reference to preferred embodiments thereof, the present invention is not limited to such embodiments and can be deviated from the spirit of the present invention, as will be readily understood by those skilled in the art. It is possible to change appropriately within the range not to be.

For example, in the above embodiment, the exhaust passage 58 is branched from the pilot chamber 84 (via the radial groove 86), but from the second pilot passage 56B downstream of the throttle element 60 (pilot chamber 84 side). A branched passage may be used. If necessary, all or part of the

throttle elements

60, 160, the first pilot passage 56A, the second pilot passage 56B, and the exhaust passage 58 can be provided outside the

valve housing

28 or 128. The second outlet port 127 may be a port open to the atmosphere.

If necessary, the

throttle elements

60 and 160 may be fixed throttles, or may consist of simple narrow passages or narrow passages. If desired, an air reservoir 90 can be connected to increase the effective volume of the

pilot chambers

84, 184, as shown by phantom lines in FIGS. 1-3, 6-8.

Further, as shown in FIG. 19, a throttle element 88 may be provided in the middle of the exhaust passage 58. The throttle element 88 serves to reduce the speed at which the compressed air in the pilot chamber 84 is discharged from the air blow nozzle 102 through the exhaust passage 58, the passage switching valve 20, the outlet pipe 14, and the trigger valve 104, The higher the aperture of the aperture element 88, the longer the air blow stop time. The aperture of the aperture element 88 is required to be lower than the aperture of the aperture element 60.

The compression coil springs 82 and 182 can be exchanged and the spring constant can be selected and set. Further, as shown in FIG. 20, the axial position of the spring retainer 110 that forms the spring end receiving portion on the valve housing 28 side with respect to the valve housing 28 is configured to be displaceable by the adjusting screw 112, whereby the compression coil The preload of the spring 82 can be variably set. As a result, the blowing time and stop time can be changed or variably set.

In addition, the intermittent air generating device according to the present invention is not limited to the application to the air blowing device, and a drive device such as an air cylinder device and various pneumatic devices such as a diaphragm device and a pump device are connected to the outlet port 24. It can also be applied to various air devices.

Further, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the spirit of the present invention.

The Japanese patent application that serves as the basis for the priority under the Paris Convention of the present application (the disclosure of Japanese Patent Application No. 2014-215517 filed on October 22, 2014 is hereby incorporated by reference in its entirety.

DESCRIPTION OF SYMBOLS 10 Air pressure source 12 Inlet pipe 14 Outlet pipe 20 Passage switching valve 22 Port 22 Inlet port 24 Outlet port 26 Exhaust port 28 Valve housing 30 Cylindrical chamber 36 Sleeve 38 Main valve chamber 40 Plug 42 End wall 44 Central recessed part 46 O ring 48 Inlet opening 50 Outlet opening 52 Inlet passage 54 Outlet passage 56A First pilot passage 56B Second pilot passage 58 Exhaust passage 60 Throttle element 62 Needle valve hole 64 Needle valve body 64A Inner end 68 Central recess 72 O-ring 74 Main valve body 76 Circle Ring recess 78 Land 80 Land 84 Pilot chamber 86 Radial groove 86A Radial groove 86B Radial groove 88 Throttle element 90 Air reservoir 100 Air gun 102 Air blow nozzle 104 Trigger valve 106 Trigger lever 110 Retainer 120 passage switching valve 122 inlet port 124 first outlet port 126 exhaust port 127 second outlet port 128 valve housing 129 outlet passage 130 cylindrical chamber 131 throttle element 136 sleeve 138 main valve chamber 140 plug 141 rubber packing 142 end wall 144 central recess 146 O-ring 148 Inlet opening 150 Outlet opening 152 Inlet passage 154 Outlet passage 156A First pilot passage 156B Second pilot passage 158 Exhaust passage 160 Throttle element 162 Needle valve hole 164 Needle valve body 164A Inner end 168 Central recess 172 O-ring 174 Main valve Body 175 End face 176 Annular recess 178 Land 184 Pilot chamber 185 Expanded pilot chamber 186 Radial groove 192 Hole 193 Movable plug 194 Tool engaging portion 195 O-ring 20 Close valve 202 valve chamber 204 valve body 206 stopper pin 208 O-ring 210 gap 214 button 220 on-off valve 222 valve chamber 224 valve spool 225 communication hole 226 operator 230 closing valve 240 off valve

Claims

A pilot chamber, an inlet port connected to an air pressure source, an outlet port, an exhaust port, and when the pressure in the pilot chamber is less than a predetermined value, the inlet port and the outlet port communicate with each other to connect the exhaust port. A passage switching valve having a valve body that is closed and has a valve body that closes the inlet port and communicates the outlet port and the exhaust port when the pressure in the pilot chamber is equal to or higher than a predetermined value;
A pilot passage connecting the pilot chamber to the air pressure source;
A throttle element provided in the middle of the pilot passage;
An intermittent air generating apparatus comprising: an exhaust passage that connects the pilot chamber or the pilot passage downstream of the throttle element to the exhaust port.
A pilot chamber, an inlet port connected to an air pressure source, an outlet port, an exhaust port, and when the pressure in the pilot chamber is less than a predetermined value, the inlet port and the outlet port are shut off, and the exhaust port A passage switching valve having a valve body that connects the inlet port and the outlet port and opens the exhaust port when the pressure in the pilot chamber is equal to or higher than a predetermined value;
A pilot passage connecting the pilot chamber to the air pressure source;
A throttle element provided in the middle of the pilot passage;
An intermittent air generating device comprising: an exhaust passage connecting the pilot chamber or the pilot passage downstream of the throttle element to the exhaust port.
The intermittent air generating device according to claim 1 or 2, wherein the throttle element is in a fully closed state that selectively closes the pilot passage.
The intermittent air generator according to claim 1 or 2, further comprising an on-off valve that selectively opens the pilot chamber to the atmosphere.
The intermittent air generator according to claim 1 or 2, further comprising an on-off valve that opens and closes the pilot passage.
The intermittent air generating device according to any one of claims 1 to 5, wherein the aperture element is a variable aperture element capable of changing an aperture degree.
The intermittent air generating device according to any one of claims 1 to 6, further comprising an air reservoir connected to the pilot chamber.
The intermittent air generating device according to any one of claims 1 to 7, further comprising a throttle element provided in the middle of the exhaust passage.
The passage switching valve is operated by an equilibrium relationship between the load due to the pressure in the pilot chamber and the spring load of the compression coil spring, and the passage switching valve has a mechanism for variably installing the preload of the compression coil spring. The intermittent air generating device according to any one of claims 1 to 8, which is incorporated.
The intermittent air generator according to any one of claims 1 to 9, wherein the internal volume of the pilot chamber is changeable.
The intermittent member according to any one of claims 1 to 10, wherein at least a part of the throttle element, the pilot passage, and the exhaust passage is provided in a valve housing that accommodates the valve body. Air generator.