TWI855205B - Pressure regulating valve - Google Patents

Abstract

A pressure regulating valve is provided, which can suppress the pressure change of the supplied gas, realize high-precision regulation, and prevent the occurrence of unexpected changes in the set pressure. The pressure regulating valve 1 has an on-off valve 30 for opening and closing the first flow path 20 connected from the primary port 12 at one end of the cylindrical body shell 10 to the secondary port 14 at the other end. The primary port 12 and the secondary port 14 are arranged so that the central axis of the air inlet 16a and the central axis of the air outlet 18a are coaxial, and the pressure-bearing area of the primary port side 12 is provided by the first sealing member 31 of the valve body 31 of the on-off valve 30. The inner diameter of the seat surface 36a at the position where the seal 34 abuts is determined, and the pressure-bearing area on the secondary port 14 side is determined by the inner diameter of the main body shell 11 at the position where the second seal 35 of the valve body 31 abuts. The pressure regulating valve includes an offset component 62 that offsets the valve body 31 in a direction from the primary port 12 to the secondary port 14 in parallel with the center axis of the inlet port 16a and the center axis of the exhaust port 18a.

Description

Pressure regulating valve

The present invention relates to a pressure regulating valve, and more particularly, to a pressure regulating valve for regulating the pressure of gas supplied to an external air pressure device to a predetermined value.

In automated equipment production lines that assemble mechanical devices, electronic devices, etc., many devices that use the pneumatic devices exemplified above are used in cylinders, etc. Since each of these pneumatic devices is set to a working pressure, a pressure regulating valve has been used to adjust the pressure of the supplied gas to a specified value.

For example, in the conventional pressure regulating valve, the structure described in Patent Document 1 (Japanese Patent Laid-Open No. 2004-192462) is known. The pressure regulating valve structure is configured to set the pressure arbitrarily between the high pressure range and the low pressure range by operating the action dial.

In addition, the "pressure regulating valve" and the "safety valve (relief valve)" are different in purpose and structure. The "safety valve (relief valve)" mentioned above releases pressure to protect equipment when the pressure of the supplied gas exceeds the specified value due to some abnormality. [Prior technical literature] [Patent literature]

Patent document 1: Japanese Patent Publication No. 2004-192462

[Problems to be solved by the invention]

Here, in the conventional pressure regulating valve illustrated in Patent Document 1, the pressure can be adjusted arbitrarily by operating the operating dial, but the time required for adjustment becomes long, and even a slight touch on the operating dial may cause an unexpected change in the set pressure. In addition, the provision of the adjustment mechanism increases the number of parts and complicates the structure.

In addition, the connected air pressure equipment sets the working pressure of the supplied gas to a specified value in order to obtain accurate operation. Therefore, the pressure regulating valve is required to be able to adjust the pressure of the supplied gas to the specified value with high accuracy and as little fluctuation as possible. [Means for solving the problem]

The present invention is completed in view of the above situation, and its purpose is to provide a pressure regulating valve that can suppress the pressure variation of the supplied gas to achieve high-precision regulation, and can reduce the number of regulation man-hours and prevent unexpected changes in the set pressure.

As an implementation form, the aforementioned problem is solved by the solution disclosed below.

The disclosed pressure regulating valve is used to regulate the pressure of gas supplied to an external air pressure device to a specified value, and is characterized in that it includes: a cylindrical main body shell; a primary port, the primary port is arranged at the first end of the main body shell and has an air inlet connected to the external gas supply source; a secondary port, the secondary port is arranged at the second end of the main body shell and has an air outlet connected to the external air pressure device; a first flow path, the first flow path connects the air inlet and the air outlet to allow fluid to pass; an on-off valve, the on-off valve is arranged in the middle of the first flow path to open and close the flow path; a cylindrical guide member, the guide member is arranged inside the main body shell, and the outer diameter of the guide member is larger than the outer diameter of the main body shell. The inner diameter of the main body shell is small; and a cylindrical flow path component, the flow path component is arranged inside the guide component, and the outer diameter of the flow path component is smaller than the inner diameter of the guide component; the primary port and the secondary port are arranged so that the central axis of the air inlet and the center of the air exhaust port are coaxial, and the flow path component has: a first space, the first space constitutes the first flow path at the radial center; a first through hole, the first through hole connects the inside of the first space with the outside; and a seat surface, the seat surface constitutes the valve seat of the on-off valve at the end close to the secondary port; the on-off valve has a valve body, in which the valve body has a side shape close to the primary port. The valve body is provided with a small diameter portion with a relatively small outer diameter, and a large diameter portion with a relatively large outer diameter is formed on the side close to the secondary port, and a first seal is embedded outside the small diameter portion, and a second seal is embedded outside the large diameter portion; the valve body is configured to have: a second space, the second space constitutes the first flow path at the radial center; and a second through hole, the second through hole connects the inside of the second space with the outside, the small diameter portion is embedded in the guide member so as to be reciprocatingly movable, and the large diameter portion is embedded in the main body shell so as to be reciprocatingly movable, the pressure-bearing area on the primary port side is defined by the inner diameter of the seat surface at the position where the first seal abuts, and the pressure-bearing surface on the secondary port side is defined by the inner diameter of the seat surface at the position where the first seal abuts, and the pressure-bearing surface on the secondary port side is defined by the inner diameter of the seat surface at the position where the first seal abuts. The volume is determined by the inner diameter of the main body shell at the position where the second sealing member abuts; the pressure regulating valve also includes an offset member, which offsets the valve body and the central axis of the air inlet and the central axis of the exhaust port in parallel along the direction from the primary port to the secondary port; the third space between the inner surface of the peripheral wall portion of the guide member and the outer surface of the peripheral wall portion of the flow path forming member constitutes a second flow path; the second flow path is connected to the first flow path through the first through hole of the flow path forming member and the second through hole of the valve body, and a check valve is provided in the middle, and the check valve only allows flow from the secondary port to the primary port.

According to the disclosed pressure regulating valve, the pressure fluctuation of the gas supplied to the external air pressure equipment can be suppressed, thereby achieving high-precision regulation. In addition, since a structure without an operating dial is achieved, the number of adjustment man-hours can be reduced and unexpected fluctuations in the set pressure can be prevented.

[Form used to implement the invention]

Hereinafter, the embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 and FIG. 2 are both front cross-sectional views (schematic views) showing an example of a pressure regulating valve 1 of the present embodiment, FIG. 1 is a state where the on-off valve 30 is "open", and FIG. 2 is a state where the on-off valve 30 is "closed". In addition, FIG. 3 is an enlarged view of a flow path component 50 of the pressure regulating valve 1, and FIG. 4 is an enlarged view of a valve body 31 of the on-off valve 30 in the pressure regulating valve 1. In addition, in all the accompanying drawings used to describe the embodiment, the same symbols are sometimes assigned to components having the same function, and their repeated descriptions are omitted.

The pressure regulating valve 1 of this embodiment is used to supply gas (air) whose pressure is regulated to a specified value to pneumatic equipment installed in an automatic equipment production line for assembling mechanical devices, electronic equipment, etc. Specific examples of the aforementioned pneumatic equipment include actuators such as cylinders, vacuum generators, blowers, etc. In order to perform accurate operations, the pressure (working pressure) of the gas supplied to the aforementioned pneumatic equipment is set to a specified value. In addition, regarding the common characteristics of these pneumatic equipment, the following operation is performed, that is, the pressure on the secondary side, that is, the internal pressure (working pressure) of the aforementioned pneumatic equipment, is reduced by reducing the pressure on the primary side of the pressure regulating valve 1.

As shown in Figs. 1 and 2, the pressure regulating valve 1 has a main body shell 10 of a cylindrical shape (for example, the overall schematic shape is cylindrical), a primary port 12 is provided at a first end 10a, and a secondary port 14 is provided at another second end 10b. For example, the primary port 12 is configured by embedding a first pipe joint 16 at the first end 10a, and the opening of the first pipe joint 16 is configured as an air inlet 16a (wherein, it is an exhaust port when the gas flows in the opposite direction) directly connected to an external gas supply source (not shown) such as an air compressor or connected to an external gas supply source (not shown) such as an air compressor via a pipe. In addition, the secondary port 14 is configured to have a second pipe joint 18 embedded in the second end 10b, and the opening of the second pipe joint 18 is configured to be an exhaust port 18a (wherein, it is an air inlet when the gas flows in the opposite direction) directly connected to the external air pressure equipment or connected to the external air pressure equipment through a pipe. In addition, in the manufacturing process, according to the situation that the valve body 31 (described later) of the on-off valve 30 is installed in the main body shell 10, the second pipe joint 18 is configured to be fixed to the cover member 22 embedded in the second end 10b of the main body shell 10. In addition, the first pipe joint 16 and the second pipe joint 18 use well-known pipe joints, and their detailed structures are omitted.

A first flow path 20 is provided inside the main body housing 10. The first flow path 20 connects the air inlet 16a and the air outlet 18a to allow fluid to pass through. In addition, an on-off valve 30 is provided in the middle of the flow path of the first flow path 20. The valve body 31 of the on-off valve 30 reciprocates in a direction parallel to the central axis C to open and close the flow path (as described later).

As a characteristic structure of this embodiment, the primary port 12 and the secondary port 14 are configured so that the central axis of the air inlet 16a and the central axis of the air outlet 18a are coaxially located (here, on the C axis). Thus, in conjunction with the structure of the roughly cylindrical main body shell 10, the pressure regulating valve 1 can be formed into a slender and compact shape. In particular, the entirety can be accommodated radially within the outer diameter of the main body shell 10, so that it can be installed in a narrower place than conventional devices.

In order to realize the above structure, the pressure regulating valve 1 has the following internal structure. First, there is a cylindrical guide member 40 (as an example, the schematic shape is cylindrical), which is arranged inside the body shell 10, has a predetermined portion whose outer diameter is smaller than the inner diameter of the body shell 10, and has a central axis coaxial with the central axis C of the body shell 10. In this embodiment, the end of the guide member 40 on the primary port 12 side is set as an integral structure continuous with the inside of the body shell 10. However, it is not limited to the above structure, and the guide member 40 can also be set as a structure separated from the body shell 10. In addition, the material constituting the main housing 10 and the guide member 40 can be appropriately selected from metal materials or resin materials.

In addition, a flow path component 50 having a cylindrical shape (for example, a schematic shape is a cylindrical shape with different diameters) is provided inside the guide member 40, has a predetermined portion with an outer diameter smaller than the inner diameter of the guide member 40, and has a central axis coaxial with the central axis C of the main body housing 10. Here, a first space 52 constituting the first flow path 20 (20A) is provided at the radial center, and a first through hole 54 is provided at a position closer to the primary port 12 than the check valve 60 described later, and the first through hole 54 connects the inside of the first space 52 with the outside. In addition, in the present embodiment, the flow path component 50 is provided as a structure separate from the guide member 40. In addition, the material constituting the flow path component 50 can be appropriately selected from metal materials or resin materials.

Next, the on-off valve 30 of this embodiment will be described. The valve body 31 of the on-off valve 30 has a relatively small diameter portion 31a formed on the side close to the primary port 12, and has a relatively large diameter portion 31b formed on the side close to the secondary port 14. Here, a first seal 34 is embedded outside the small diameter portion 31a (for example, a front end small diameter portion 31c with a smaller diameter is formed at the front end of the small diameter portion 31a) and abuts against a valve seat 36 (described later) of the on-off valve 30, and a second seal 35 is embedded outside the large diameter portion 31b and abuts against (slidably contacts) the peripheral wall portion 11 (inner surface 11a) of the main body housing 10. In addition, a second space 32 constituting the first flow path 20 (20B) is provided at the radial center, and a second through hole 33 is provided near the front end of the small diameter portion 31a, and the second through hole 33 connects the inside of the second space 32 with the outside. In addition, the material constituting the valve body 31 can be appropriately selected from metal materials or resin materials.

The valve body 31 having the above structure is configured such that the small diameter portion 31a can be reciprocatingly embedded in the tube of the guide member 40, and the large diameter portion 31b can be reciprocatingly embedded in the tube of the main body shell 10.

On the other hand, the valve seat 36 for contacting and separating with the valve body 31 of the on-off valve 30 is provided in the flow path component 50. Specifically, the seat surface 36a of the valve seat 36 is formed at the end 50a of the flow path component 50 close to the secondary port 14. The aforementioned seat surface 36a is formed as an inclined surface (chamfered shape) whose diameter expands from the inner surface 56a of the peripheral wall portion 56 to the end surface 58. In this embodiment, the first seal 34 provided at the end of the small diameter portion 31a of the valve body 31 close to the primary port 12 contacts and separates with the seat surface 36a provided in the flow path component 50 to open and close the first flow path 20 (that is, the switching between the connection and non-connection of the first flow path 20A and the first flow path 20B).

Furthermore, the pressure regulating valve 1 of the present embodiment further includes an offset member 62 for offsetting the valve body 31 of the on-off valve 30 in a direction from the primary port 12 to the secondary port 14 in parallel with the central axis of the air inlet 16a and the central axis of the air outlet 18a (i.e., in parallel with the central axis C of the body housing 10). The offset member 62 is disposed so that a part or the whole of the offset member 62 is accommodated in the fourth space 44 between the inner surface 11a of the peripheral wall portion 11 of the body housing 10 and the outer surface 42b of the peripheral wall portion 42 of the guide member 40. Here, a third through hole 19 is provided at a predetermined position of the peripheral wall portion 11 of the main housing 10 (a position closer to the primary port 12 than the second seal 35), and the third through hole 19 connects the inner surface 11a with the outer surface 11b. The third through hole 19 is provided to prevent the valve body 31 from being immobilized due to the closed space for accommodating the biasing member 62. In addition, as an example, the biasing member 62 uses a coil spring formed of a metal material, but is not limited to this.

Thus, the on-off valve 30 can be set to the so-called normally open state (the state shown in FIG. 1 ). On this basis, the pressure of the gas delivered from the exhaust port 18a of the secondary port 14, that is, the working pressure of the external air pressure equipment, can be set to a specified value by setting the spring coefficient of the biasing member 62 (here, a coil spring).

Thus, the pressure regulating valve 1 of this embodiment is a mechanism that does not have a pressure regulating mechanism for setting an operating dial, but sets the pressure on the secondary port 14 side by selecting a biasing member 62 (helical spring) pre-installed during manufacturing. Therefore, the following technical problem can be solved: in the conventional pressure regulating valve illustrated in Patent Document 1, even a slight touch on the operating dial will produce an unexpected change in the set pressure. Moreover, it is also possible to achieve a reduction in the number of adjustment man-hours, a reduction in the number of parts, and a simplification of the structure.

Here, in the on-off valve 30 of the pressure regulating valve 1 for regulating pressure, the pressure receiving area on the primary port 12 side is defined by the inner diameter of the seat surface 36a at the position where the first seal 34 abuts, and the pressure receiving area on the secondary port 14 side is defined by the inner diameter of the body housing 10 at the position where the second seal 35 abuts.

As a result of careful research conducted by the inventors of the present case, it was found that by configuring the valve body 31 in such a way that the ratio of the pressure-bearing area on the primary port 12 side to the pressure-bearing area on the secondary port 14 side is 1:25 or more (more preferably 1:28 or more), when the pressure of the gas flowing into the primary port 12 side changes, the pressure change of the gas sent out from the secondary port 14 side can be suppressed, thereby achieving high-precision pressure regulation. Here, the measured data in the comparative experiment of the pressure characteristics of the conventional pressure regulating valve is shown in FIG5 (as an example, the case of 1:28). The horizontal axis is the pressure of the gas flowing into the primary port 12, and the vertical axis is the pressure of the gas delivered from the secondary port 14. The data of the pressure regulating valve 1 of this embodiment are represented by a solid line, and the data of the conventional pressure regulating valve (the applicant's conventional product RVU6-6 model) are represented by a dotted line. As shown in the figure, the following result can be obtained: compared with the conventional pressure regulating valve, the pressure fluctuation of the gas delivered from the secondary port 14 can be suppressed to be extremely stable relative to the pressure fluctuation of the gas flowing into the primary port 12. Although the characteristics are slightly inferior to those described above, even if the pressure-receiving area ratio is configured to be 1:20 or more according to the required specifications of the connected air pressure equipment and the ratio is reduced relative to the above ratio, the pressure variation suppression effect can be fully obtained and further miniaturization can be achieved. On the other hand, in the case of trying to give priority to miniaturization (especially radial miniaturization) over the pressure variation suppression effect, by configuring the pressure-receiving area ratio to be 1:10 or more and reducing the ratio relative to the above ratio, the miniaturization effect can be significantly obtained.

In this way, the air pressure device connected to the secondary port 14 sets the working pressure of the supplied gas to a specified value in order to obtain accurate operation. According to the pressure regulating valve 1 of this embodiment, the pressure of the gas supplied from the secondary port 14 can be adjusted with high precision so that the pressure becomes the specified value with as little variation as possible, thereby achieving accurate and stable operation of the connected air pressure device.

On the other hand, the air pressure device for supplying gas to the pressure regulating valve 1 of the present embodiment has the following characteristics: the pressure of the gas on the secondary port 14 side, that is, the internal pressure (working pressure) of the air pressure device is reduced according to the reduction of the pressure of the gas on the primary port 12 side. As a structure for realizing the above-mentioned operation, in the present embodiment, the third space 46 between the inner surface 42a of the peripheral wall portion 42 of the guide member 40 and the outer surface 56b of the peripheral wall portion 56 of the flow path forming member 50 has a second flow path 48. In more detail, the second flow path 48 is configured such that when the on-off valve 30 is in a closed state (i.e., the pressure of the gas on the secondary port 14 side is made to reach a specified value, etc., so that the pressure of the gas on the primary port 12 side is lower than the pressure of the gas on the secondary port 14 side), it is connected to the first flow path 20 through the first through hole 54 of the flow path constituent component 50 and the second through hole 33 of the valve body 31 to become a flow path, and a check valve 60 is provided in the middle of the flow path of the second flow path 48, and the check valve 60 only allows flow from the secondary port 14 to the primary port 12.

With the above-described structure, the pressure regulating valve 1 can be used to regulate the pressure of gas supplied to an actuator such as an air cylinder, a vacuum generator, a blower, or other air pressure equipment to a predetermined value.

Next, the operation of the pressure regulating valve 1 having the above-mentioned structure will be described with reference to FIGS. 1 and 2 .

First, at the beginning of use, the on-off valve 30 is in the "open" state as shown in FIG1. Then, gas (compressed air as an example) is sent from an external gas supply source (not shown) to the air inlet 16a of the first pipe joint 16 of the primary port 12, and the gas flows through the first flow path 20A in the flow path component 50 and the first flow path 20B in the valve body 31 as shown by arrow A, and is supplied from the exhaust port 18a of the second pipe joint 18 of the secondary port 14 to the external air pressure device (not shown).

Next, the gas supply from the exhaust port 18a to the external air pressure device continues, and the internal pressure (operating pressure) of the external air pressure device is increased to a predetermined value through the biasing member 62. Thus, the process of operating the external air pressure device at a predetermined internal pressure (operating pressure) is performed.

At this time, the pressure of the gas on the secondary port 14 side reaches a predetermined value, and the on-off valve 30 is switched to the "closed" state as shown in Fig. 2. In this state, the gas in the pressure regulating valve 1 does not flow.

Then, the pressure of the gas on the primary port 12 side is reduced. As a result, the gas is sent from the external air pressure device to the exhaust port 18a of the second pipe joint 18 of the secondary port 14, and the aforementioned gas flows in the first flow path 20B in the valve body 31 as shown by arrow B, and then flows from the second through hole 33 to the second flow path 48, and then flows from the first through hole 54 to the first flow path 20A in the flow path component 50, and is sent out from the air inlet 16a of the first pipe joint 16 of the primary port 12. As a result, the internal pressure (working pressure) of the external air pressure device is reduced, and the preparation process for the next work is performed.

As described above, according to the disclosed pressure regulating valve, the pressure fluctuation of the gas supplied to the external air pressure equipment can be suppressed, thereby achieving high-precision regulation. In addition, since a structure without an operating dial can be achieved, the number of adjustment man-hours can be reduced and unexpected changes in the set pressure can be prevented.

In addition, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the scope of the present invention. In particular, the present invention can also be applied to supplying gas to equipment other than the exemplified air pressure equipment.

1: Pressure regulating valve 10: Body shell 12: Primary port 14: Secondary port 16: First pipe joint 16a: Inlet port 18: Second pipe joint 18a: Exhaust port 19: Third through hole 20: First flow path 30: On-off valve 31: Valve body 31a: Small diameter part 31b: Large diameter part 32: Second space 33: Second through hole 34: First seal 35: Second seal 36: Valve seat 36a: Seat surface 40: Guide component 44: Fourth space 46: Third space 48: Second flow path 50: Flow path component 52: First space 54: First through hole 60: Check valve 62: Offset component C: Center axis

FIG. 1 is a schematic diagram (front sectional view) showing an example of a pressure regulating valve according to an embodiment of the present invention. FIG. 2 is a schematic diagram (front sectional view) showing an example of a pressure regulating valve according to an embodiment of the present invention. FIG. 3 is an enlarged view of a flow path component of the pressure regulating valve shown in FIG. 1 and FIG. 2. FIG. 4 is an enlarged view of a valve body of an on-off valve of the pressure regulating valve shown in FIG. 1 and FIG. 2. FIG. 5 is measurement data of pressure characteristics of a pressure regulating valve according to an embodiment of the present invention and a pressure regulating valve according to a conventional embodiment.

1: Pressure regulating valve

10: Main body shell

10a: First end

10b: Second end

11: Peripheral wall

11a: Inner surface

11b: External surface

12: primary port

14: Secondary port

16: First pipe joint

16a: Air intake

18: Second pipe joint

18a: Exhaust port

19: The third through hole

20(20A,20B):First flow path

22: Cover component

30: Open/Close Valve

31: Valve body

31a: Trail section

31b: Main Path

32: Second Space

33: Second through hole

34: First seal

35: Second seal

36: Valve seat

40: Guidance component

42: Peripheral wall

42a: Inner surface

42b: Outer surface

44: The fourth space

46: The Third Space

48: Second flow path

50: Flow path components

52: First Space

54: First through hole

56: Peripheral wall

60: Check valve

62: Offset member

C: Center axis

Claims (4)

A pressure regulating valve adjusts the pressure of gas supplied to an external air pressure device to a specified value, and is characterized in that it includes: a cylindrical body shell; a primary port, the primary port is arranged at the first end of the body shell and has an air inlet connected to an external gas supply source; a secondary port, the secondary port is arranged at the second end of the body shell and has an air outlet connected to the external air pressure device; a first flow path, the first flow path connects the air inlet and the air outlet to allow fluid to pass; an on-off valve, the on-off valve is arranged in the middle of the first flow path to open and close the flow path; a cylindrical guide member, the guide member is arranged inside the body shell, and the outer diameter of the guide member is larger than the outer diameter of the guide member. The inner diameter of the aforementioned main body shell is small; and a cylindrical flow path component, the aforementioned flow path component is arranged inside the aforementioned guide component, the outer diameter of the aforementioned flow path component is smaller than the inner diameter of the aforementioned guide component, the aforementioned primary port and the aforementioned secondary port are arranged so that the central axis of the aforementioned air inlet and the center of the aforementioned air exhaust port are coaxial, and the aforementioned flow path component has: a first space, the aforementioned first space constitutes the aforementioned first flow path at the radial center; a first through hole, the aforementioned first through hole connects the inside of the aforementioned first space with the outside; and a seat surface, the aforementioned seat surface constitutes the valve seat of the aforementioned on-off valve at the end close to the aforementioned secondary port, The aforementioned on-off valve has a valve body, in the aforementioned valve body, at the side close to the aforementioned primary port A small diameter portion with a relatively small outer diameter is formed, and a large diameter portion with a relatively large outer diameter is formed on the side close to the secondary port, and a first seal is embedded outside the small diameter portion, and a second seal is embedded outside the large diameter portion, and the valve body is configured to have: a second space, the second space constitutes the first flow path at the radial center; and a second through hole, the second through hole connects the inside of the second space with the outside; the small diameter portion is reciprocatingly embedded in the guide member, and the large diameter portion is reciprocatingly embedded in the main body housing, the pressure-bearing area on the primary port side is defined by the inner diameter of the seat surface at the position where the first seal abuts, and the pressure-bearing surface on the secondary port side is The volume is determined by the inner diameter of the main body shell at the position where the second seal abuts. The pressure regulating valve further includes a biasing member, which biases the valve body in parallel with the central axis of the air inlet and the central axis of the air exhaust in the direction from the primary port to the secondary port. The third space between the inner surface of the peripheral wall of the guide member and the outer surface of the peripheral wall of the flow path forming member constitutes a second flow path. The second flow path is connected to the first flow path through the first through hole of the flow path forming member and the second through hole of the valve body, and a check valve is provided in the middle. The check valve only allows the flow from the secondary port to the primary port. For example, the pressure regulating valve of claim 1, wherein the valve body is constructed such that the ratio of the pressure-bearing area on the primary port side to the pressure-bearing area on the secondary port side is greater than 1:10. As in the pressure regulating valve of claim 1 or 2, the offset member is disposed in a fourth space between the inner surface of the peripheral wall of the body shell and the outer surface of the peripheral wall of the guide member. For a pressure regulating valve as claimed in claim 1 or 2, the external air pressure device is an actuator, vacuum generator, or blower that reduces the internal pressure by reducing the pressure on the primary port side.