JPH0443656Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fluid control valve disposed in a flow path for a fluid having a high temperature.

[Prior Art] A valve main body having a plurality of ports and a valve seat in a flow path that communicates these ports, a valve body that opens and closes the valve seat, and a drive unit that drives the valve body, the drive unit Fluid control valves in which a valve body opens and closes a valve seat by the operation of the fluid control valve are already known without being particularly exemplified.

The above-mentioned known fluid control valve has no problem when the main fluid flowing through the valve body is low temperature, but when the temperature of the main fluid is high, the valve body is heated by the high temperature main fluid, and this causes the driving part to There is a problem in that heat is transferred to the drive unit, causing deterioration and damage to seal members and the like in the drive section.

In order to solve this problem, we created a heat radiation space between the valve body and the drive part using the mounting base of the drive part, and connected the valve stem and drive shaft to a hollow space with a heat radiation hole that opens into the heat radiation space. The electric valve connected by the connecting member is
This was proposed in Japanese Utility Model Application No. 55-64571.

However, in this already proposed valve, the mounting base and connecting member are not made of a material with low heat conductivity, so it is necessary to insert a heat insulating plate when attaching the mounting base to the valve body, and the heat dissipation space is If the length in the axial direction is not made long, the heat dissipation by the connecting member will be insufficient, so in order to reduce the amount of heat transferred to the drive part, the valve becomes large and the installation space becomes large.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is to provide a fluid control valve in which the amount of heat transferred from the valve body to the drive section is small, and which can be made smaller as a whole.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a valve body having a plurality of ports and a valve seat in a flow path that communicates these ports, and a valve body that approaches and separates from the valve seat. In a fluid control valve consisting of a main valve including a valve body that opens and closes a valve seat and a drive section that drives the main valve, and a pilot valve that supplies and discharges pilot fluid to and from the drive section, there is a gap between the valve body and the drive section. A heat dissipation space that is open to the outside is formed by a plurality of spacers made of a material with low heat conductivity and a set nut, and the tip of the valve stem of the valve body is made spherical, and the tip of the valve stem and the rod of the drive section are connected. In the heat dissipation space, axial and radial plays are provided and the pilot valves are connected by pins, and the exhaust port of the pilot valve is communicated with the outside through the breathing chamber of the drive section.

[Function] Even when high-temperature main fluid flows into the valve body and its temperature rises, the provision of a heat dissipation space open to the outside air between the valve body and the drive section allows the valve body to maintain its temperature. Heat is dissipated.

In this case, the heat dissipation space is formed by a set nut and a plurality of spacers made of a material with low heat conductivity interposed between the valve body and the drive part, and the valve tip has a spherical shape. By connecting the rods with pins with play in the axial and radial directions in the heat radiation space to reduce the amount of heat transfer between them, even if the axial length of the heat radiation space is short, The amount of heat transferred to the drive section can be extremely small.

Furthermore, by discharging the pilot fluid to the outside through the breathing chamber of the drive section, the heat is radiated from the drive section by the pilot fluid each time the valve seat is opened and closed by the valve element. It is also possible to reduce the temperature rise in the drive section.

Therefore, not only can thermal deterioration and thermal damage to the driving section be prevented, but also the axial length of the heat radiation space can be shortened, so that the fluid control valve can be downsized as a whole.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, and this fluid control valve includes a main valve 1, a pilot valve 2 for supplying and discharging pilot air to the main valve 1, and a valve of the main valve 1. A heat dissipation space, which will be described later, is provided between the main body 3 and the drive section 4.

The valve body 3 includes an input port 5 for pressurized fluid (steam, water, oil, air, etc.), an output port 6, and a valve seat 7 in a flow path that communicates these ports, and opens and closes the valve seat 7. The valve stem 9 of the valve body 8 extends tightly through a seal packing 11 provided on a first plate 10 that closes the valve body 3.

The cover 13 constituting the outer casing of the drive unit 4 is closed on the valve body 3 side by a second plate 14, and a slidable piston 15 is provided between the top wall of the cover 13 and the second plate 14. The breathing chamber 1 opens to the outside through the pressure chamber 16 and the breathing port 17a.
7, and a return spring 18 is installed in the breathing chamber 17.

A plurality of spacers 2 formed in a cylindrical shape made of a material with low heat conductivity are provided between the valve body 3 and the drive section 4.
1, a heat dissipation space 20 open to the outside by...
are formed, and both are integrally connected by connecting bolts 22, . . . (see FIG. 3) passing through spacers 21, . Further, the set nut 23 screwed onto the second plate 14 is also made of a material with low heat conductivity, and the tool hole 23 formed in the nut 23 is made of a material with low heat conductivity.
By inserting and rotating appropriate tools in a, . . . , the tips thereof are brought into pressure contact with the first plate 10.

In this case, as shown in FIG.
By providing the radial holes 21a,...
Heat transfer by the connecting bolts 22, . . . can be further reduced.

The rod 15a of the piston 15 extends tightly through the second plate 14 and is connected to the set nut 2.
3, a valve stem 9 having a spherical tip
and are connected by a pin 24 with play in the radial and axial directions (see FIG. 2). When connected in this way, the contact area between the valve stem 9 and the rod 15a is reduced, which suppresses heat transfer from the valve stem 9 to the rod 15a, and eliminates the need for precision machining such as aligning the centers of the two. It is possible,
Furthermore, the tool holes 23a, . . . of the set nut 23 can further reduce heat transfer from the valve stem 9 to the rod 15a.

The pilot drive unit 30 in the pilot valve 2 includes a pilot pressure chamber 32 and a feedback chamber 33, which are partitioned by a diaphragm 31, and the pilot pressure chamber 32 is a pressure reducing valve, an electropneumatic proportional valve, etc. (not shown), etc. The feedback chamber 33 communicates with the output port 6 of the main valve 1 through a passage 27, and has a return spring 35 compressed therein.

The pilot valve 2 has an inlet port 2a that communicates with a port 26 opened in the cover 13, an output port 2b that communicates with the pressure chamber 16 of the main valve 1 via a passage 13a, and an external connection via a breathing chamber 17 and the breathing port 17a. The output port 2c in the feedback chamber 33 is provided with a discharge port 2c communicating with the output port 2c in the feedback chamber 33.
If the force is larger than the sum of the acting force of the feedback fluid pressure and the biasing force of the return spring 35, the flow path between the inlet port 2a and the outlet port 2b is connected, and if it is smaller than the sum, the flow path between the outlet port 2b and the discharge port 2c It is composed of a well-known 3-port valve with communicating flow paths.

In the above embodiment, when a predetermined signal air pressure set by a pressure reducing valve or an electro-pneumatic proportional valve acts on the pilot pressure chamber 32, the flow path between the inlet port 2a and the outlet port 2b of the pilot valve 2 is brought into communication. Since pilot air is supplied to the pressure chamber 16 of the main valve 1 through the passage 13a, the valve body 8 opens the valve seat 7 and fluid such as steam flows out to the output port 6. When the acting force of the feedback chamber 33 becomes larger than the opposing force of the pilot pressure chamber 32 due to an increase in the fluid pressure of the output port 6, the passage between the outlet port 2b and the discharge port 2c is brought into communication due to the displacement of the diaphragm 31, so that the pressure increases. The chamber 16 communicates with the outside via the discharge port 2c etc., and the valve body 8 closes the valve seat 7,
As a result, when the acting force of the pilot pressure chamber 32 becomes larger than the counterforce of the feedback chamber 33, the valve body 8 opens the valve seat 7, and these operations cause the fluid pressure of the output port 6 to become equal to the signal air pressure. The pressure is adjusted to a certain level.

In the control valve, when the temperature of the main fluid flowing through the valve body 3 is high, the valve main body 3 is heated by the main fluid.
heat is dissipated to the outside from a heat dissipation space 20 provided between the drive unit 4 and the heat dissipation space 20 is formed by the spacers 21, . The valve stem 9 and the rod 15a are connected by the pin 24 with play in the radial and axial directions with respect to the spherical surface of the tip of the valve stem, so that the contact area between the two is small. Since the amount of heat transferred from the engine 3 to the drive unit 4 is small, and furthermore, the heat is dissipated from the drive unit 4 by the pilot fluid discharged through the breathing chamber 17, the temperature rise in the drive unit 4 is small. , thermal deterioration, thermal damage, etc. of the sealing member and the like in the drive section 4 can be prevented.

Therefore, the axial length of the heat dissipation space 20 can be shortened, thereby making it possible to downsize the fluid control valve as a whole.

Furthermore, the heat dissipation space 20 is formed by a plurality of spacers 21,
... and the set nut 23, the structure is simple and the valve can be made inexpensive.

[Effects of the invention] In the fluid control valve of the invention, a heat dissipation space between the valve body and the driving part is formed by a spacer and a set nut made of a material with low heat transfer properties.
By connecting the tip of the spherical valve stem and the rod with a pin with play in the axial and radial directions within the heat dissipation space, heat transfer between these members is reduced, and furthermore, the drive section Since the heat is dissipated by the pilot fluid discharged through the breathing chamber, the temperature rise in the drive part can be kept extremely small even if the axial length of the heat dissipation space is short.

Therefore, the fluid control valve that prevents deterioration and damage to the drive unit due to heat can be downsized and can be installed in a narrow space.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention (normally closed), FIG. 2 is an enlarged sectional view of the connecting portion between the rod and the valve stem, and FIG. 3 is a sectional view of the main parts. 1... Main valve, 2... Pilot valve, 2c... Discharge port, 3... Valve body, 4... Drive unit, 5, 6
... Port, 7 ... Valve seat, 8 ... Valve body, 9 ... Valve stem, 15a ... Rod, 17 ... Breathing chamber, 20 ...
...Heat radiation space, 21...Spacer, 23...Set nut, 24...Pin.

Claims (1)

[Claims for Utility Model Registration] A valve body having a plurality of ports and a valve seat in a flow path that communicates these ports, a valve body that approaches and separates from the valve seat to open and close the valve seat, and a valve body that drives the valve body. A fluid control valve comprising a main valve having a driving part that supplies and discharges pilot fluid to and from the driving part, and a plurality of spacers made of a material with low heat conductivity between the valve body and the driving part. and a set nut to form a heat dissipation space open to the outside, and the valve stem tip of the valve body is made into a spherical shape, and the valve stem tip and the rod of the drive section are arranged in the axial and radial directions within the heat dissipation space. A fluid control valve characterized in that the pilot valve has a play and is connected by a pin, and the discharge port of the pilot valve is communicated with the outside through a breathing chamber of the drive unit.