KR20220080704A - Conversion valve - Google Patents

Abstract

[assignment]
A switching valve capable of controlling the flow rate in stages and preventing a delay in the flow rate switching point when restarting after stopping use is provided.
[Solution]
The selector valve 1 includes a main valve 50 movable within the sleeve 10 , and a first flow path 31 communicating with the pilot supply port 26 and the opening port 28 and a first opening/closing valve ( 41), a second flow path 32 and a second on/off valve 42 that communicate with the supply port 20 and the open port 28, and a third that communicates with the supply port 20 and the first exhaust port 22 The flow path 33 and the third opening/closing valve 43, the supply port 20 and the second exhaust port 24 are provided with a fourth flow path 34 communicating, the first opening/closing valve 41 and the second opening/closing valve 24 are provided. The valve 42, when the valve body and the valve seat are in contact with the movement direction of the main valve 50, and the pilot supply air is greater than a predetermined pressure, the first on-off valve 41 and the second on-off valve 42 Close and open the third on-off valve 43 , and when the pressure is less than a predetermined pressure, the first on-off valve 41 and the second on-off valve 42 are opened and the third on-off valve 43 is closed.

Description

switching valve {CONVERSION VALVE}

The present invention relates to a switching valve for pneumatic use.

BACKGROUND ART A device using an air cylinder is often used in an automatic equipment line or the like for assembling a mechanical device, an electronic device, or the like. However, if the movement speed of the piston in the air cylinder is increased, the cycle time can be made small, while the impact at the time of stopping becomes large, resulting in a problem that the life of the air cylinder is shortened.

Conventionally, a shock absorber (for example, oil type) is provided in the mechanism part to which the piston of the air cylinder is connected so that the impact at stop does not increase even if the moving speed of the piston of the air cylinder is increased, and the air cylinder (piston) is stopped It was common to mitigate the impact of poetry.

Alternatively, there is also disclosed a technique related to an air cylinder with a cushion mechanism that achieves impact relief at a stop by providing a cushion mechanism for relieving an impact in the air cylinder itself (see Patent Document 1: Japanese Patent Application Laid-Open No. 2003-254303). .

Patent Document 1 Japanese Patent Laid-Open No. 2003-254303 Patent Document 2: Japanese Patent Laid-Open No. 2014-055631

However, for example, in the case of a configuration in which a shock absorber is provided to relieve the impact when the piston of the air cylinder is stopped, since it is necessary to assemble the shock absorber into the device, the mechanism is complicated, and the parts cost and assembly cost are increased. There are challenges such as ascending.

In order to solve the problem, the inventors of the present application, without using a shock absorber, by a simple configuration, the moving speed in one stroke of an air cylinder (piston) assembled to an external pneumatic device in stages A speed controller with a cushioning function that can be controlled by a sprinter was developed (Patent Document 2: Refer to Japanese Patent Application Laid-Open No. 2014-055631).

Here, when the speed controller with a cushion function is used to stepwise control the moving speed in one stroke of the air cylinder (piston) of an external pneumatic device, the switching point of the speed defined by the switching point of the gas flow rate passing through It becomes important to stabilize For example, if a delay occurs at the speed switching point, the cushion does not function until the stroke end of the air cylinder (piston), and a large impact may occur.

As the inventors of the present application conducted intensive research, in a conventional speed controller with a cushioning function, when restarting after stopping use for a certain period of time, the main valve or the main valve-equivalent member sticks, and the flow rate at the first stroke after restarting The challenge was found that there could be a delay at the transition point, that is, the speed transition point.

The present invention is made in view of the above circumstances, is a configuration used by being connected to an external pneumatic device, and can control the flow rate of gas passing through stepwise, and when restarting after stopping use for a certain period of time, the flow rate An object of the present invention is to provide a switching valve that can prevent a delay in the switching point of

As one embodiment, the above problem is solved by means of a solution disclosed below.

The disclosed selector valve has a cylindrical shape and includes a sleeve having a supply port, a first exhaust port, a second exhaust port, a pilot supply port, and an opening port formed to communicate inside and outside, and axially movable within the sleeve; a first flow passage communicating the pilot supply port and the open port, a second flow passage communicating the supply port and the open port, and the supply port and the first passage having a provided main valve and passing through the sleeve A third flow path communicating with the exhaust port, and a fourth flow path communicating the supply port and the second exhaust port are provided, and a first on/off valve for opening and closing the first flow path, and opening and closing the second flow path A second on-off valve and a third on-off valve for opening and closing the third flow passage are provided, wherein each of the first on-off valve, the second on-off valve, and the third on-off valve includes one of a valve body and a valve seat. The sleeve is provided integrally or separately, and the other is provided integrally or separately with the main valve, and in the first on-off valve and the second on-off valve, the valve body and the valve seat are arranged in a direction of movement of the main valve and arranged so as to be retractable in a parallel direction, and when the pressure of the pilot supply air supplied to the pilot supply port is greater than a predetermined pressure, the main valve is moved to the first end side in the sleeve, and the first opening and closing When the third on-off valve is opened while closing the valve and the second on-off valve, and the pressure of the pilot supply air supplied to the pilot supply port is less than a predetermined pressure, the main valve moves to the second opening in the sleeve. It is characterized in that it has a configuration in which the first on-off valve and the second on-off valve are opened and the third on-off valve is closed when the end is moved.

According to the disclosed selector valve, when used in connection with an external pneumatic device, it is possible to control the flow rate of the gas passing therethrough in stages. Moreover, when restarting after stopping use for a fixed period of time, it can prevent that a delay arises in the switching point of a flow volume.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the structural example of the selector valve which concerns on embodiment of this invention, and also an operation explanatory drawing.
Fig. 2 is a schematic diagram showing a configuration example of a selector valve according to an embodiment of the present invention and also an operation explanatory diagram.
Fig. 3 is a schematic diagram showing a configuration example of a selector valve according to an embodiment of the present invention, and also an operation explanatory diagram.
Fig. 4 is a circuit diagram showing an example when the selector valve according to the embodiment of the present invention is connected to an external pneumatic device.
5 is an explanatory diagram for explaining a problem to be solved by the selector valve according to the embodiment of the present invention (experimental data using a conventional mechanism);
It is explanatory drawing for demonstrating the effect achieved by the selector valve which concerns on embodiment of this invention (experimental data by the selector valve which concerns on embodiment of this invention).

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, embodiment of this invention is described in detail. 1 to 3 are front sectional views (schematic views) showing a configuration example of the selector valve 1 according to the present embodiment, and also serves as an operation explanatory diagram. In addition, in all the drawings for demonstrating embodiment, the same code|symbol is attached|subjected to the member which has the same function, and the repetition description may be abbreviate|omitted.

As an example, the switching valve 1 according to the present embodiment is an exhaust (C) of a double acting type air cylinder (hereinafter simply referred to as "air cylinder") assembled in an external pneumatic equipment constituting an automatic equipment line or the like. It is arranged (connected) in a flow path through which compressed air of a predetermined pressure discharged by the movement of the piston flows through it, and the operating speed of the air cylinder C is increased in stages (for example, in two stages of high speed and low speed). A usage mode, such as controlling, is assumed.

1 to 3 , the selector valve 1 is disposed in an axial direction (central axis S) within a sleeve 10 having a cylindrical shape (for example, a substantially cylindrical shape) having a space at the center in the radial direction. ) along the direction) is configured to be provided with a main valve 50 movably disposed. In addition, as a constituent material of the selector valve 1, a resin material (for example, POM, PBT, etc.) according to the conditions of use, except for parts in which rubber, elastomer, etc., such as a seal member, which will be described later, are used; A metal material (for example, a stainless alloy, an aluminum alloy, brass, etc.) is used suitably.

The sleeve 10 according to the present embodiment has a cylindrical shape (for example, a substantially cylindrical shape) having a cylindrical shape (as an example, a substantially cylindrical shape) in the inner cylindrical portion of the main sleeve 12 having a space at the radial center thereof ( As an example, the first guide sleeve 14 having a substantially cylindrical shape) and the second guide sleeve 16 having a cylindrical shape (as an example, substantially cylindrical shape) having a space portion at the center in the radial direction are each a seal member (18A, 18B, 18C) (as an example, O-ring which consists of rubber|gum, an elastomer, etc.) is interposed and it has a structure in which the installation was carried out. Therefore, the main valve 50 moving in the axial direction in the sleeve 10 is, more specifically, in the first guide sleeve 14 and the second guide sleeve 16 (that is, in each space) in the axial direction. It is structured to move in the right direction. However, the configuration of the sleeve 10 is not limited to the above, and as a modification, a configuration that forms the entire sleeve 10 integrally, and the first guide sleeve 14 and the second guide sleeve 16 are integrally formed. It is good also as a structure etc. which are formed (all are not shown).

In the sleeve 10, the inside and the outside of the cylindrical portion communicate with each other (that is, so that the inside and outside of the fitted main sleeve 12, the first guide sleeve 14, and the second guide sleeve 16 communicate with each other) The following ports which were opened are provided. Specifically, a supply port 20 , a first exhaust port 22 , a second exhaust port 24 , a pilot supply port 26 , and an open port 28 are provided.

Further, for each of these ports, the following flow passages configured to pass between the inner cylinder portion of the sleeve 10 and the outer peripheral portion of the main valve 50 are provided (indicated in FIG. 2 to avoid cluttering the drawings). Specifically, a first flow path 31 communicating the pilot supply port 26 and the open port 28, a second flow path 32 communicating the supply port 20 and the open port 28, a supply port ( A third flow path 33 communicating 20 and the first exhaust port 22 and a fourth flow path 34 communicating the supply port 20 and the second exhaust port 24 are provided.

In addition, the first on/off valve 41 for opening and closing the first flow path 31 , the second on/off valve 42 for opening and closing the second flow path 32 , and a third on/off valve for opening and closing the third flow path 33 . 43 is provided (indicated in Figs. 2 and 3 to avoid complication of the drawings).

The first on-off valve 41 has a valve body 41a formed as a separate body using rubber, elastomer, etc., provided in the main valve 50, and the valve seat 41b is provided with a sleeve 10 (this embodiment). In this case, it is provided integrally with the 1st guide sleeve 14 (it may be used separately). Moreover, as a modification, the structure etc. which provide the valve body 41a in the sleeve 10, and arrange|position the valve seat 41b to the main valve 50 are also considered (not shown).

In the same way, in the second on/off valve 42, a valve body 42a formed as a separate body using rubber, elastomer, or the like is provided in the main valve 50, and the valve seat 42b is provided in the sleeve 10 ( In this embodiment, it is provided integrally with the 1st guide sleeve 14 (it may be set as a separate body). Moreover, as a modification, the structure etc. which provide the valve body 42a in the sleeve 10, and arrange|position the valve seat 42b to the main valve 50 are also considered (not shown). In addition, as for the third on-off valve 43, a valve body 43a formed as a separate body using rubber, elastomer, or the like is provided in the main valve 50, and the valve seat 43b is provided in the sleeve 10 (this embodiment). In the form, it is provided integrally with the 1st guide sleeve 14 (it may be set as a separate body). Moreover, as a modification, the structure etc. which provide the valve body 43a in the sleeve 10, and arrange|position the valve seat 43b to the main valve 50 are also considered (not shown).

Moreover, in this embodiment, the valve body 41a of the 1st on-off valve 41 and the valve body 42a of the 2nd on-off valve 42 are provided in the packing member 40 of an integral structure, and the said packing The member 40 is set as the structure in which the outer peripheral part of the main valve 50 was installed. According to this, the number of parts can be reduced, and cost reduction can be aimed at. However, it is not limited to this structure, You may comprise the valve body 41a and the valve body 42a separately (not shown).

Here, a gas (for example, compressed air of about 0.5 MPa) of a predetermined pressure is supplied (input) to the pilot supply port 26 as "pilot supply air". On the other hand, to the supply port 20, gas (for example, compressed air of about 0.5 MPa) of a predetermined pressure is supplied (input) as "supply air". Each gas (compressed air) may be supplied from, for example, a common supply source (eg, a compression pump, etc.) (not shown). However, it is not limited to this, It is also possible to set it as the structure supplied from another supply source (as an example, a compression pump etc.) (not shown).

The selector valve 1 provided with these structures operates as follows. Specifically, when the pressure of the pilot supply air supplied to the pilot supply port 26 is greater than a predetermined pressure (hereinafter, referred to as a “first set pressure”), the main valve 50 moves the first in the sleeve 10 . It becomes the state (state shown in FIG. 1) moved to the edge part (right end part in the figure) 10a side, and while making the 1st on-off valve 41 and the 2nd on-off valve 42 into "closed", the 3rd The on/off valve 43 is set to "open". On the other hand, when the pressure of the pilot supply air supplied to the pilot supply port 26 is smaller than the predetermined pressure (the first set pressure), the main valve 50 is opened in the sleeve 10 at the second end (the left end in the figure). (10b) is moved to the side (state shown in Fig. 3), the first on-off valve 41 and the second on-off valve 42 are set to "open", and the third on-off valve 43 is turned " close". The state shown in Fig. 2 is a state in the middle of transitioning from the state shown in Fig. 1 to the state shown in Fig. 3, or in the middle of transitioning from the state shown in Fig. 3 to the state shown in Fig. 1 .

According to this, as an example, only the circuit for exhausting the supply air supplied to the supply port 20 from both the first exhaust port 22 and the second exhaust port 24 and the second exhaust port 24 . It becomes possible to perform switching from the circuit to exhaust. That is, since it becomes possible to switch the exhaust flow path, specifically, to the third flow path 33 , the fourth flow path 34 , and the fourth flow path 34 , the cross-sectional area of the flow path (the narrowest part By switching part)), it becomes possible to perform switching of the flow volume of the compressed air which passes. Moreover, the 3rd flow path 33 and the 4th flow path 34 are provided with the throttle valve 62 and the throttle valve 64, respectively (refer FIG. 4), The flow volume control of the compressed air passing through each flow path is adjusted. possible configurations.

Here, as an example of use (connection example) of the selector valve 1 according to the present embodiment, as shown in the circuit diagram of FIG. 4 , the supply port 20 of the selector valve 1 is air assembled to an external pneumatic device. It is used by being connected to the exhaust port of the cylinder (C). In this case, when compressed air of a predetermined pressure (here, the above-mentioned 0.5 MPa or the like) is supplied to the intake port of the air cylinder C and the piston moves, the compressed air of the same pressure is discharged from the exhaust port. This compressed air is configured to be supplied (input) to the supply port 20 of the selector valve 1 .

Accordingly, a circuit for exhausting the supply air supplied to the supply port 20 by the switching valve 1 from both the first exhaust port 22 and the second exhaust port 24, and the second exhaust port ( 24), it becomes possible to obtain the action of performing the switching by the circuit exhausting from the bay. That is, it becomes possible to switch the cross-sectional area of the flow path for exhausting the external pneumatic device (air cylinder C) in steps (here, in two steps). Thereby, the operation speed (axial movement speed) of the piston of the air cylinder C switches from a high-speed movement to a low-speed movement, and it becomes possible to generate|occur|produce a cushioning function. Therefore, since the speed immediately before stopping of a piston can be reduced, it becomes possible to relieve|moderate the impact at the time of stopping.

In addition, as another example, for example, by configuring an on/off valve (not shown) for opening and closing the fourth flow path 34 , the supply air supplied to the supply port 20 is reduced to the first exhaust port 22 . ) and a circuit evacuating only from the second exhaust port 24, it is possible to switch. Also by such a structure, it becomes possible to generate|occur|produce a cushioning function by performing the switching of the flow volume of the compressed air passing through the same effect as the above.

By the way, if only the cushioning function is generated during the piston operation of the air cylinder C, as described above, it can also be realized by a conventional speed controller with a cushioning function, a spool type selector valve, or the like. However, in their conventional products, when resuming after stopping use for a certain period of time, the internal main valve (or main valve equivalent member) is stuck, and the flow rate switching point, ie, speed switching point, at the first stroke after restart. Problems that cause delays have been identified. Here, the experimental results using the conventional apparatus are shown in FIG. 5 . Two types of time from use to resumption are set. Plot A1 is standard data at the time of normal operation, Plot A2 is data at the time of restarting after 10 minutes of suspension of use, Plot A3 is data at the time of restarting after 3 hours of suspension of use. In both cases, the vertical axis indicates the pressure value of the pilot supply air, and the horizontal axis indicates the response delay time value when the main valve 50 responds (starts to move) in response to the pressure change of the pilot supply air. As is also clear from this graph, the longer the time of stopping use, the longer the delay time until the main valve 50 responds (movement start point: point E in Fig. 5), that is, the degree of sticking of the main valve 50. It can be seen that increases

In order to solve such a subject, the selector valve 1 which concerns on this embodiment is equipped with the following structure. First, in the first on-off valve 41 and the second on-off valve 42, the valve body and the valve seat (specifically, the valve body 41a and the valve seat 41b, and the valve body 42a) and the valve seat 42b) are arranged to be folded in a direction parallel to the moving direction of the main valve 50 (that is, the same as the direction parallel to the central axis S of the inner cylinder portion of the sleeve 10). The study of the inventors of the present application has clarified that the main valve sticking, which is a subject, is due to the occurrence of a close contact state by pressure contact between the valve body provided in each on-off valve and the corresponding valve seat. On the other hand, according to the above configuration, even if the valve body (here, 41a, 42a) and the corresponding valve seat (here, 41b, 42b) are in pressure contact, and a close contact occurs, the close contact can be easily eliminated. , it becomes possible to eliminate (or suppress) the occurrence of sticking.

Here, the experimental result using the switching valve 1 which concerns on this embodiment provided with the said structure is shown in FIG. Plot B1 is standard data at the time of normal operation, and Plot B2 is data at the time of restarting after 3 hours of suspension of use. In addition, the indexes of the vertical axis and the horizontal axis are the same as in FIG. 5 . As is clear from this graph, according to the selector valve 1 according to the present embodiment, it can be seen that the degree of sticking of the main valve 50 is almost non-existent (or extremely small) even when the time of stopping use is long. have.

In addition, as a modification, the valve seats 41b, 42b, 43b are formed using a metal material or a resin material, and all or part of them are in contact with the corresponding valve bodies 41a, 42a, 43a. It is good also as a structure in which the plating process or grease application|coating which reduces the friction coefficient of a surface was made|formed. According to this, even if the valve body (here, 41a, 42a) and the corresponding valve seat (here, 41b, 42b) are in pressure contact, even if a close contact occurs, it is easy to cancel the close contact, and the occurrence of sticking is reduced. It becomes possible to further enhance the effect of removing (or suppressing).

Moreover, in the selector valve 1 which concerns on this embodiment, the minimum cross-sectional area of the 2nd flow path 32 (here, the position which becomes the narrowest part between the inner cylinder part of the 1st guide sleeve 14 and the outer peripheral part of the main valve 50) It has a characteristic structure that it is smaller than the minimum cross-sectional area of the 1st flow path 31 (here, the position downstream from the 1st on-off valve 41 to the outlet of the opening port 28). For example, if the minimum cross-sectional area of the 2nd flow path 32 becomes larger than or equal to the minimum cross-sectional area of the 1st flow path 31, the compressed air supplied to the supply port 20 at the time of movement of the main valve 50 is pilot-supplied. It flows into the port 26 side, and the thrust generated by the pressure of pilot supply air rises more than the setting. As a result, a problem arises that the main valve 50 is not stably switched at a desired timing.

In response to this problem, in the present embodiment, the opening port 28 for releasing the exhaust of the pilot supply air to the atmosphere is provided (details will be described later), and as described above, the minimum cross-sectional area of the second flow path 32 is the first By a configuration smaller than the minimum cross-sectional area of the flow path 31, it is possible to solve the problem. That is, according to these structures, when switching (moving) the main valve 50 in the direction in which the 1st on-off valve 41 is opened, the pilot supply air can be released to atmosphere at once, and the 2nd flow path 32 can be opened. The action of flowing through the supply port 20 side can be made almost negligible (or extremely small). In addition, since the supply air flowing from the supply port 20 through the second flow passage 32 can flow through the open port 28 side instead of the pilot supply port 26 side, the pressure of the pilot supply air The action of raising the generated thrust beyond the setting can be almost negligible (or extremely small). Therefore, it becomes possible to perform movement of the main valve 50, ie, switching, stably at a desired timing. In addition, the timing of switching can be set by the speed controller 66 (refer FIG. 4).

As described above, in the present embodiment, the opening port 28 is configured to open the flow-through gas under atmospheric pressure. However, it is not limited to this structure, Even if it is a structure which opens the flow-through gas under a micro pressure (for example, about 0.2 MPa or less), the same effect can be acquired.

Moreover, in the selector valve 1 which concerns on this embodiment, the biasing member (for example, a coil spring, or its An outer spring member) 60 is further provided. According to this, the movement operation|movement of the main valve 50 can be assisted, and when there is no application of supply air (or a small case), the attitude|position of the main valve 50 can be stabilized. Incidentally, the biasing force of the biasing member 60 (eg, a coil spring) is appropriately set depending on the size of the sleeve 10 or the main valve 50 , but as an example, a bias of about 1N at the time of assembly set to generate power.

In the case of such a configuration including the spring 60 , the “first set pressure” described above is the pressure of the supply air supplied to the supply port 20 and the biasing member 60 (eg, a coil spring). It is set as the pressure which added the pressure which converted the force of .

Here, as described above, the supply air (compressed air) supplied to the supply port 20 and the pilot supply air (compressed air) supplied to the pilot supply port 26 are supplied from a common supply source. (In addition, "supply air" is supplied via the air cylinder C). Therefore, the structure which adjusts so that the pressure of pilot supply air may become larger than a 1st set pressure is needed.

In this regard, in the main valve 50 according to the present embodiment, the pressure receiving area of the pilot supply air supplied from the pilot supply port 26 (specifically, the valve body 41a (valve seat 41b)) The pressure-receiving area defined by the diameter of the contact position with the supply port 20) is the pressure-receiving area of the supply air supplied from the supply port 20 (specifically, the diameter of the valve body 42a (contact position with the valve seat 42b)). It is comprised so that it may become larger than the prescribed|regulated water pressure area). According to this configuration, the thrust for moving the main valve 50 in the direction of the first end 10a by the pressure of the pilot supply air is applied to the main valve 50 by the pressure of the supply air and the biasing force of the biasing member 60 . It can be set to be larger than the thrust to move in the direction of the second end 10b. In addition, as an example, in the use state in which the supply port 20 is connected to the exhaust port of the air cylinder C, the flow velocity of the exhaust gas becomes a high state and the pressure of the supply air becomes a low state, so this effect acts overlappingly, and the action of generating and maintaining a state in which the thrust by the pressure of the pilot supply air becomes higher increases.

As described above, according to the disclosed selector valve, it becomes possible to control the flow rate of the gas at a predetermined pressure supplied (input) to the supply port in steps (here, two steps) at the time of exhausting the gas. As an example, if it is configured to be connected to the exhaust port of an air cylinder assembled into an external pneumatic device, the piston of the air cylinder is moved at a high speed for a short period of time after starting to move, thereby reducing the operating time. It becomes possible to switch the moving speed from high speed to low speed at the set timing just before this stop. Therefore, it becomes possible to aim at the shock relief at the time of the piston stop of an air cylinder without using a shock absorber.

Moreover, when restarting this switching valve after stopping use for a fixed period of time, it becomes possible to prevent that a delay arises in the switching point of the flow volume resulting from sticking of a main valve with respect to a sleeve.

In addition, this invention is not limited to embodiment demonstrated above, It cannot be overemphasized that various changes are possible in the range which does not deviate from this invention.

Claims (6)

A sleeve having a cylindrical shape and having a supply port, a first exhaust port, a second exhaust port, a pilot supply port, and an open port formed to communicate inside and outside;
and a main valve arranged movably in the axial direction in the sleeve;
a first flow passage communicating the pilot supply port and the open port, a second flow passage communicating the supply port and the open port, and a third communicating the supply port and the first exhaust port to pass through the sleeve a flow path, and a fourth flow path communicating the supply port and the second exhaust port, a first opening/closing valve opening and closing the first flow path, a second opening/closing valve opening/closing the second flow path, and the A third opening/closing valve for opening and closing the third flow path is provided;
In all of the first on-off valve, the second on-off valve, and the third on-off valve, one of the valve body and the valve seat is provided integrally or separately in the sleeve, and the other is provided integrally or separately in the main valve, ,
In the first on-off valve and the second on-off valve, the valve body and the valve seat are arranged to be folded in a direction parallel to the movement direction of the main valve,
When the pressure of the pilot supply air supplied to the pilot supply port is greater than a predetermined pressure, the main valve is moved to the first end side in the sleeve and the first on-off valve and the second on-off valve are closed; When the third on-off valve is opened together and the pressure of the pilot supply air supplied to the pilot supply port is less than a predetermined pressure, the main valve is moved to the second end side in the sleeve, and the first A switching valve comprising an on-off valve and a configuration in which the third on-off valve is closed while the on-off valve and the second on-off valve are opened. The method of claim 1,
and a minimum cross-sectional area of the second passage is smaller than a minimum cross-sectional area of the first passage. 3. The method of claim 1 or 2,
and a biasing member for biasing the main valve in a direction for moving the main valve to the second end in the sleeve. 4. The method of claim 3,
The predetermined pressure is a pressure obtained by adding a pressure obtained by converting the pressure of the supply air supplied to the supply port and the biasing force of the biasing member. 5. The method according to any one of claims 1 to 4,
The valve seat is formed using a metal material or a resin material, and plating or grease application is performed on a contact surface with the valve body. 6. The method according to any one of claims 1 to 5,
A switching valve, characterized in that the supply port is connected to an exhaust port of an air cylinder assembled to an external pneumatic device and used.

Images