JPH0333576A - High pressure air switching valve - Google Patents

Abstract

PURPOSE:To obtain a low-priced switching valve for high pressure air by pressure lowering operation and improve durability against switching shock at the time of high pressure by reducing the pressure of a part of the high pressure operating air in a main valve to use it as the pilot fluid of a pilot valve. CONSTITUTION:When the pressure in the valve chamber 16 of a pressure reducing valve 9 is lower than the specified pressure, the force of a spring 15 works powerfully, so that a valve seat 10 is released, and high pressure air in a flow passage 8 flows into the valve chamber 16 and fed into the pressure feed port of a pilot valve 3 through a pilot flow passage 17. When the pressure in the valve chamber 16 rises to the specified pressure, a piston 14 is pushed against the force of the spring 15 so as to close the valve seat 10. In order to obtain the smooth movement of the piston 14 at this time, an exhaust port R is formed at a pressure reducing valve main body 13. As the pressure reducing valve 9 is provided at the flow passage 8 communicated with the pressure feed port P of the main valve, the pilot valve 3 receives the air reduced at a medium pressure or the like, in spite of utilizing a part of high pressure air.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a high pressure air switching valve.

[Prior art]

2. Description of the Related Art A switching valve is known that has a main valve and a pilot valve, and switches the main valve body using pilot fluid sent from the pilot valve.

Conventionally, it was generally 1.5 to 10 due to the regulations of the High Pressure Gas Control Law.
Although switching valves for pneumatic pressure of 10 kgf/cm2 or more have been produced, almost no switching valves for pneumatic pressure of 10 kgf/cm2 or more have been produced.

Recently, due to changes in the scope of application of the High Pressure Gas Control Law, 10
It has become possible to use a switching valve for pneumatic pressures of "kgf/cm2 to 50 kgf/cm" as a general-purpose air switching valve.

When using a conventional high-pressure solenoid valve as a switching valve for high pressures of 10 kgf/cm or more, a direct-acting metal spool valve can operate at a higher pressure than a normal medium-pressure operating valve. As such, a pilot type switching valve with a small diameter and increased pressure resistance of the pilot valve as a whole will be used.In the case of a direct acting metal spool valve, a very large solenoid is used to handle the high pressure. This poses a problem in terms of practicality.In the case of a pilot-operated switching valve, in order to increase the pressure, it is necessary to increase the area of the piston that drives the main valve to counteract the increased friction of the seal. Accordingly, it is necessary to increase the flow rate of the pilot valve, which requires a pilot valve that is larger, has higher pressure resistance, and is more expensive than the conventional medium-pressure type.

In pilot switching valves, if the valve body of the main valve is a pressure-balanced spool or slide valve, the minimum driving force of the valve body increases only slightly as the pressure of the operating air increases. It is. Furthermore, even in a poppet valve with unbalanced pressure, the minimum driving force is the unbalanced valve plus the friction. Therefore, in the case of a pilot-operated switching valve, the driving ability of the pneumatic piston that drives the valve body of the main valve only needs to be slightly larger than the above-mentioned minimum driving force.

However, in general, in the case of a pylon 1 type switching valve, the working air of the main valve is used as the pilot fluid of the pilot valve, so the driving ability of the pneumatic piston that drives the valve body of the main valve is approximately proportional to the supply air pressure, The higher the air pressure becomes, the more the driving capacity of the pneumatic piston becomes.

In high-pressure pilot operated switching valves, the structure of the pilot valve tends to be large in order to withstand high pressure, but the driving capacity of the pilot valve is sufficient to keep the main valve's valve body from moving. This resulted in a problem of low efficiency despite the high cost.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an inexpensive high-pressure air switching valve that has a structure similar to that of conventional medium-pressure products, can be used at high pressures, and is inexpensive.

[Means to solve the problem]

The present invention solves the above-mentioned problem in a high-pressure switching valve in which a part of the high-pressure working air of the main valve is reduced in pressure via a pressure reducing valve, and the air is used as the pilot fluid of the pilot valve. This was achieved using an air switching valve.

The high-pressure working air of the main valve can be branched from the main valve body, the sub-plate attached to the main valve, or the manifold to which the main valve is attached and introduced into the pilot valve, and depending on the branch position, the pressure reducing valve is It can be incorporated into either the main valve body, subplate, or manifold.

[Effect]

According to the present invention, a main valve is used to switch a high-pressure air path of 10 kgf/cm2 or more, and a part of the high-pressure air is guided to a pressure reducing valve built into the main valve or a subplate or manifold to which the main valve is attached. , the same pressure as the compressed air of the switching valve conventionally used in pressure reducing valves, e.g.
The air pressure is reduced to 8 kgf/cm2, and the reduced air is introduced into the pressure supply boat of the pilot valve.

The compressed chamber air whose flow path has been switched by the pilot valve is supplied to the main valve as a pilot fluid when the valve body of the main valve is switched and moved.

According to the present invention, the main valve is made as a switching valve with a structure that can withstand high-pressure air, but the pilot valve must be of the same size or the same product as the pilot valve used in conventional medium-pressure switching valves. is now possible. Therefore, it has become possible to reduce costs and development man-hours.

〔Example〕

The details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, a high pressure air switching valve 1 according to the present invention has a main valve 2 and a pilot valve 3.

The main valve 2 has a pressure supply port P, a first output robot A,
It has a valve body 4 including a second discharge boat B, a first discharge boat R, and a second discharge port R2. A spool 5 is slidably supported in the valve body 4 as a valve body. The spool 5 is provided with a driving piston 6, and the spool 5 is driven by the driving piston 6 being moved by pilot fluid from the pilot valve 3 supplied to the piston chamber 7. The functional portion of the main valve as a valve is the same as that of a known spool valve, so a description thereof will be omitted.

In the valve body 4 of the main valve 2, a pressure reducing valve 9 is assembled or integrally formed in a passage 8 communicating with the pressure supply valve P.

As shown in FIG. 2, the pressure reducing valve 9 has a valve seat 10 formed on the valve body 4 and a poppet valve body 11 seated on the valve seat 10. The valve body 11 is pushed against the valve seat 10 by a spring 12. Pressed by

A piston 14 is slidably guided inside the pressure reducing valve body 13 attached to the main valve body 4, and the piston 14 engages with the valve stem 5 of the poppet valve body 11. The piston 14 is pressed against the poppet valve body 11 by a spring 15. Due to the pressure balance between the force acting on the piston 14 by the spring 15, the pressure acting on the piston 14 and the poppet valve body 11 due to the fluid pressure in the valve chamber 16, and the air pressure of the pressure supply port acting on the poppet valve body 11. A poppet valve body 11 opens and closes a valve seat 10. When the pressure in the valve chamber 16 is below a predetermined pressure, the force of the spring 15 acts strongly, the valve seat 1O is opened, and the high pressure air in the flow path 8 flows into the valve chamber 16, and the pilot flow path 1
7 to the pressure supply port of the pilot valve 3.

FIG. 2B is an abbreviated symbol representation of the structure shown in FIG.

Since the pilot valve 3 itself is a well-known pilot solenoid valve 3, a detailed explanation thereof will be omitted.

When the pressure inside the valve chamber 16 rises to a predetermined pressure, the piston 1
4 is pushed against the force of spring 15 to close valve seat 10.

At that time, so that the movement of the piston 14 can be obtained smoothly,
An exhaust port R is formed in the pressure reducing valve body 13.

A pressure reducing valve 9 is connected to the flow path 8 communicating with the pressure supply bow 1-P of the main valve.
By providing the pilot valve 3, air with reduced pressure is supplied to the pilot valve 3 and a part of the high pressure air is used, but the pilot valve 3 is supplied with air with reduced pressure such as intermediate pressure.

As the pressure reducing valve 9, a diaphragm type shown in FIG. 3 may be used instead of the piston type shown in FIG. 2. Since the basic structure is the same as that in FIG. 2 except that the piston 14 in FIG. 2 is replaced with a Guyaf ram 14' in FIG. 3, the same or corresponding parts will be given the same reference numerals and a description thereof will be omitted.

Compressed air as a pilot fluid whose pressure has been reduced by the pressure reducing valve 9 is supplied to the pilot valve 3, and by switching the flow path of the pilot valve 3 as a solenoid valve, the pilot fluid is transferred to the main valve 2.
is supplied to the piston chamber 7 of the valve body 4 (main valve body 4).

FIG. 4 shows a modification of the flow path compared to FIG. 1, and the basic structure is completely the same as that in FIG. 1.

In other words, this shows an example in which the R2 port is used as a high pressure supply port, the R1 port is used as a low pressure supply port, the A and B ports each have different pressure outputs, and the pressure reducing valve 9 is assembled in a flow path 8' that communicates with the R2 port. It is.

In this case, the P port becomes the exhaust port.

In the examples shown in FIGS. 1 and 4, the pressure reducing valve 9 is attached to the main valve body 4, whereas as shown in FIGS. 5 and 6, the main valve body is attached to the sub-plate 21, and the The plate 21 is provided with a pressure supply path 22, an output path 23, 24, and an exhaust path 25.
26 are formed, and each flow path of the subplate 21 is connected to each boat of the main valve body (for example, the shape T7 as in FIG. 1) through connection ports 27, 28, 29, 30, and 31 of the subplate 21. In the sub-plate type switching valve, the pressure reducing valve 9 can be incorporated into the sub-plate 21. In this case, the pressure reducing valve 9 has a pressure supply branch passage 32 branching from the pressure supply passage 22 of the sub-plate 21, and a pilot supply connection port 3 that connects with the pressure supply passage of the pilot valve of the sub-plate l-21.
It is installed between the pilot supply path 34 which passes through 3.

The operation and effect are similar to the example shown in FIG.

Furthermore, as shown in FIGS. 7 and 8, a plurality of switching valves 4
In the case of a manifold-mounted switching valve in which the valves 1 and 1 are connected by a manifold 42, the pressure reducing valve 9 can also be assembled to the manifold 42.

The pressure reducing valve 9 is installed between the pressure supply branch passage 44 branching from the pressure supply passage 43 and the pilot supply passage 46 branching from the pilot flow passage 45, as in the case of the examples shown in FIGS. 5 and 6. be done. The switching valve 41 has a main valve 2' and a pilot valve 3'.

When testing the relationship between supply pressure and driving force when the valve body of the main valve is driven by a pilot valve, the results shown in FIG. 9 were obtained. That is, the switching force required to switch and drive the spool valve, which is the valve body of the main valve, is proportional to the change in supply pressure as shown by straight line A, but does not show a very large change.

When the valve body of the main valve is a poppet valve, the switching force changes as shown by straight line B, and the change in supply pressure appears as a change in driving force more than in the case of a spool valve.

When the pilot fluid pressure of the pilot valve remains the same as the supply pressure of the main valve, the driving force changes in approximately 1:1 proportion to the supply pressure, as shown by straight line C.

In order to switch and drive the valve body of the main valve by the pilot valve, a driving force slightly higher than the value indicated by straight line A or straight line B is required. In other words, a poppet valve requires a higher driving force than point a, and a spool valve requires a higher driving force than point b.

When switching is controlled by a pilot valve in the conventional system, the supply pressure of the main valve becomes the pilot supply pressure because there is no pressure reducing valve, and the result shown by straight line C is obtained. For this reason, the valve body of the main valve is driven with a driving force considerably larger than the required switching force of the valve body, and a supply pressure of 10 kg4/cm2 or more leaves too much margin in the driving force and is rather wasted. Furthermore, it becomes necessary to strengthen the structure of the pylon 1 to the valve in terms of pressure resistance and switching shock resistance.

When a pressure reducing valve is used as in the present invention, the supply pressure to the pilot valve becomes a constant pressure or less regardless of the supply pressure of the main valve, and as shown in the curve, a predetermined pressure such as 6 kgf/c112 is reached. Up to this point, the driving force increases as the supply pressure increases, but beyond a predetermined pressure, no matter how much the main valve's supply pressure increases, the air pressure in the biloft valve remains constant, and the driving force to the main valve remains constant. It remains almost constant. As is clear from the straight lines A, B, and D in the figure, even if this pressure reducing valve is used, the amount of change in the increase in the driving force is larger than the amount of change in the required switching force within the range defined by the pressure reducing valve, and there is too much margin.

In addition, in cases such as poppet valves where the required switching force is large,
Unless the set pressure of the pressure reducing valve is increased considerably, the driving force generated by the high-pressure air may become smaller than the required driving force, and in this case, the main valve cannot be switched.

As a pressure reducing valve, as shown in FIG. 10, the piston I4 shown in FIG. It is possible to use a modified fixed ratio pressure reducing valve 9' with an offset as the pressure reducing valve main body 13' having a two-stage cylinder surface corresponding to '. The piston 14' has a valve chamber 16,
A flow path 18 is formed that connects the opening in the peripheral surface of the small diameter portion 14a at the end on the large diameter portion 14b side, and the flow path 18 can communicate with an exhaust port R formed in the pressure reducing valve body 13'. Furthermore,
The valve stem 11a of the poppet valve body 11 passes through the piston 14' in a sealed manner, and a through passage 11b formed in the poppet valve body 11 forms a spring chamber that accommodates the flow passage 8 and the spring 15 of the pressure reducing valve body 13'. 13'a can be communicated with. The poppet valve body 11 is formed with an auxiliary valve body 11c that opens and closes the flow path I8. FIG. 10B is an abbreviated symbol representation of the structure z shown in FIG. 10A.

In this pressure reducing valve 9', the air pressure in the pilot flow path 17, that is, the secondary pressure is obtained for the main valve supply air pressure in the flow path 8, i.e. - the next pressure. When the primary pressure, that is, the supply pressure of the main valve increases beyond the pressure offset by the spring 15, the secondary pressure also changes in proportion to the change in the secondary pressure. If this secondary pressure, which changes in proportion to the secondary pressure, is made into the pilot pressure, a change in driving force as shown in the straight line in Figure 9 can be obtained.For example, in the case of a poppet valve, straight line B and straight line Parallel to E, the margin force remains almost constant even if the supply pressure changes. Therefore, by selecting the amount of offset due to the spring force, the margin force can also be selected to an optimum value.

Although not specifically mentioned in the description of each of the above embodiments, it is a matter of course that sealing members are placed in necessary areas for sealing.

〔effect〕

The present invention makes it possible to use a conventionally used pilot valve while using the same high-pressure air as the main valve, which has the pressure resistance and sealing ability to handle high-pressure air. It is now possible to provide a low cost pilot operated switching valve for high pressure air.

The present invention makes it possible to cut excessive pilot pressure in switching valves that utilize high-pressure air, limit the increase in operating speed of the main valve body at high pressures, and improve switching impact durability at high pressures. We were able to avoid the decline.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a high-pressure air switching valve according to the present invention, A is a schematic sectional view, B is a schematic symbol diagram, and FIG. 2 is an explanatory diagram of a pressure reducing valve, A is a sectional diagram, B is a schematic symbol diagram, Fig. 3 is a sectional view of another embodiment of the pressure reducing valve, Fig. 4 is an explanatory diagram of another embodiment of the high pressure air switching valve, A is a schematic sectional view, B is a schematic symbol diagram, and Fig. 5 is a subplate. FIG. 6 is a front view of the sub-plate, FIG. 7 is a partially sectional front view of the manifold type switching valve, FIG. 8 is a side view of the manifold type switching valve, and FIG. The figure shows a characteristic curve showing the relationship between the supply pressure and the driving force for the main valve, and FIG. 1... High pressure air switching valve 2... Main valve 3... Pilot valve 4... Main valve body 5... Valve body
9...Reducing valve ~ Kusu Φ -651

Claims (3)

[Claims] (1) In a high-pressure switching valve that has a main valve and a pilot valve and switches the main valve by the action of pilot fluid sent through the pilot valve, the pressure supply port of the pilot valve is connected to the pressure of the main valve via a pressure reducing valve. A high-pressure air switching valve, characterized in that it is connected to a supply port, and the output port of the pilot valve is connected to the valve body operating chamber of the main valve. (2) A claim characterized in that a manifold connecting a plurality of main valves is provided, and a pressure reducing valve connected to the main valve pressure flow path of the manifold and the pressure supply port of the pilot valve is assembled to the manifold. The high-pressure air switching valve according to item 1. (3) Provide a sub-plate that can be attached to the main valve and has a pressure fluid supply path and discharge path for the main valve and a fluid supply path for the pilot valve, and a flow branching from the pressure fluid supply path for the main valve of the sub-plate. 2. The high-pressure air switching valve according to claim 1, wherein a pressure reducing valve connecting the pilot valve fluid supply channel and the pilot valve fluid supply channel is provided on the sub-plate.