JPH0942471A - Heat wind control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent stress concentration to a connection portion between a valve body and support shafts by fixing a first and second support shafts to portions of a ceramic valve body, rotationally driving the first support shaft by means of a motor, and cooling the valve body, the first and second support shafts for purging dusts. SOLUTION: In a heat control valve 10, a flow passage 14 for heat fluid composed of a heat insulative member 12 and a fire resistant member 13 is formed on an inner periphery of a metal casing 11. A ceramic valve body 15 is arranged inside the flow passage 14 in an openable/closeable manner. Portions 16, 17 of the valve body are symmetrically arranged from a peripheral edge of the valve body 15. First and second support shafts 18, 19 are engaged with the portions 16, 17. The first support shaft 18 is rotationally driven by a driving motor 21. The first and second support shafts 18, 19 are cooled by means of a cooling mechanism 20. Inactive gas is periodically supplied from a gas supply pipe 30 through the first and second support shafts 18, 19, a bearing 25, and peripheries of the portions 16, 17 of the valve body to the flow passage 14. Stress is evenly applied to the valve body 15 and the support shafts 18, 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved hot air control valve for controlling the flow rate of hot fluid.

[0002]

2. Description of the Related Art Generally, in a conventional hot air control valve, a valve body made of ceramics (SiC) supported on one side in a casing is rotatably supported. Further, the inner circumference of the casing is lined with a heat insulating material and a refractory material. Further, the valve body is connected to the drive motor via a metal valve shaft. The hot air control valve can open and close the valve body by operating the drive motor. In addition, ceramics have a limit to the size of the firing furnace, and it is not possible to make a product that is too large. Further, large products are likely to cause variations in components (specific gravity), which is also a cause of residual stress after baking.

Therefore, it has been proposed to join a ceramic product with a metal to produce a long product as shown in FIGS. FIG. 7 shows that the valve shaft 5 made of ceramic is made of metal,
For example, it is an explanation showing a stress state when the support shaft 6 formed of SUS304 or the like is shrink-fitted. In this example,
Since the tip portion 6a of the support shaft 6 is formed in a square shape, stress concentration occurs at the contact point A with the valve shaft 5, and there is a risk that the ceramic will crack.

FIG. 8 shows a case where the tip 6b is formed in a tapered shape in order to avoid stress concentration at the tip of the support shaft 6. When formed in this way, the stress concentration at the point A is somewhat alleviated, but the stress concentration still occurs at the tip edge portion of the support shaft 6. In the case shown in FIG. 8, it is reduced by about 12% as compared with the case shown in FIG.
In FIG. 9, the taper at the tip of the support shaft 6 is formed more gently than in the case shown in FIG. In the case of such a configuration, it is reduced by about 22% as compared with the case shown in FIG.

[0005]

By the way, in the above-mentioned conventional hot air control valve, since the valve body is made of ceramics, it can withstand high temperature, but stress concentration at the joint with the metallic support shaft is reduced. It still occurred and there was still the risk that the valve stem would crack at this point. Also, the valve body is
There is absolutely small gap for rotation, drawbacks dust from entering is present from the gap.

An object of the present invention is to solve the above-mentioned conventional drawbacks, and to provide a hot air control valve which does not cause stress concentration in the connection between a ceramic valve body and a metal support shaft. It is in. A further object is to provide a hot air control valve in which dust and the like do not enter the minute gaps of the valve body.

[0007]

A hot air control valve according to the present invention has a flow passage for a thermal fluid formed with a refractory heat insulating layer on the inner circumference of a metal casing, and a hot air flow control valve that can be opened and closed in the flow passage for the thermal fluid. A ceramic valve body provided, and first and second parts fixed to a part of the valve body and penetrating the casing.
A support shaft, a drive motor that rotationally drives the first support shaft, and a cooling mechanism that cools a part of the valve body and the support shaft.
An inert gas supply mechanism for dust-purging a part of the valve body and the support shaft is provided. Further, the tip ends of the first and second support shafts are formed in a tapered shape, and the fitting stress generated in the valve body fitted with the first and second support shafts is made uniform. Furthermore, the tip ends of the first and second support shafts are formed in a taper shape, and the tip end of the inner periphery that contacts the valve body is chamfered into a spherical shape.

The valve body is characterized by being fixed to the first and second supporting shafts formed in a cylindrical shape with screws. The valve element is characterized in that it is fixed to the first and second cylindrical support shafts with a screw through a cushioning material.

As described above, the hot air control valve according to the present invention is
Since the tip of the valve body support shaft is formed in a tapered shape and fitted to the valve body to make the fitting stress uniform, cracks due to stress concentration can be prevented. Further, since the inert gas supply mechanism for dust-purging a part of the valve body and the support shaft is provided, it is possible to prevent dust from entering the rotating portion of the valve body.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a hot air control valve which is an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part of a hot air control valve which is an embodiment of the present invention, and FIG. 3 is a fitting of the hot air control valve. It is an expanded sectional view showing a part. Here, the hot air control valve 10
A ceramic valve body 15 is rotatably disposed in a flow path 14 formed of a heat resistant member.

The hot air control valve 10 includes a metal casing 11
A heat-fluid flow path 14 formed with an inner lining of a heat-resistant heat-insulating material composed of a heat-insulating material 12 and a fire-resistant material 13, and a ceramic valve disposed in the heat-fluid flow path 14 so as to be openable and closable. It has a body 15. Valve body parts 16 and 17 symmetrically extending from the periphery of the valve body 15 and first support shafts 18 fitted to the first and second valve body parts 16 and 17,
The second support shaft 19 and the first and second support shafts 18, 19
A cooling mechanism 20 that cools the first support shaft 18, a drive motor 21 that rotationally drives the first support shaft 18, and the like are provided.

The metal casing 11 is formed of a steel plate in a cylindrical shape, and has connection flanges (not shown) formed at both ends. In addition, the metal casing 11 includes short tubes 22 and 23.
Is attached. The cooling mechanism 20 is provided in the short cylinder 22.
Is provided, and cooling water circulates inside. A bearing 24 is provided inside the cooling mechanism 20 formed in an annular shape, and the first support shaft 18 fitted with the part 16 of the valve body is provided.
Are rotatably supported. Further, guide cylinders 24, 24 are connected to the central cylindrical portion of the cooling mechanism 20.
The guide cylinder 24 covers the outer peripheries of the valve bodies 16 and 17 with a predetermined gap to prevent the heat insulating material 12 and the refractory material 13 from entering the valve body portions 16 and 17. ing.

The guide tube 24 reaches near the flow path 14 formed by the refractory material 13. Bearings 25 that rotatably support the first support shaft 18 and the second support shaft 19 are disposed in the short cylinders 22 and 23, respectively.

On the inner circumference of the metal casing 11, a plurality of anchor bolts (not shown) are erected inward. Then, the castable heat insulating material 12 is formed on the outer circumference of the metal casing 11 by casting or the like. Further, a castable refractory material 13 is similarly formed on the inner circumference of the castable refractory material 13 by pouring. The inner circumference of the refractory material 13 constitutes a flow path 14 for the thermal fluid. The refractory material 13 is made of high alumina or the like.

The valve body 15 is made of ceramics, and the valve body parts 16 and 17 which are also made of ceramics extend symmetrically from the periphery of the valve body 15. At the tip of the part 16 of the valve body, a stainless alloy (SUS30
4) and a first support shaft 18 having the same coefficient of thermal expansion as ceramics and made of COVAR (trademark) or the like. The first support shaft 18 is rotatably supported by the bearing 25.

The fitting of the part 17 of the valve body and the second support shaft 19 is carried out, for example, by shrink fitting. At this time, in order to prevent stress concentration in the fitting portion, as shown in FIG.
The tip of the support shaft 19 is formed into a taper 27, and an inner peripheral tip 28 that contacts the part 17 of the valve body is chamfered into a spherical shape. In addition, a part 16 of the valve body formed symmetrically
And the first support shaft 18 are fitted in the same manner. Furthermore, the first
The outer periphery of the support shaft 18 and the bearing 25 is cooled by the cooling mechanism 20 to prevent seizure.

The first support shaft 18 has a coupling 2
A drive motor 21 is connected via 6 and the valve body 15 is rotationally driven via the first support shaft 18 by a control signal from a control mechanism (not shown). In addition, the manual lever 31
When the drive motor 21 fails, the valve body 15 can be opened and closed manually.

A second support shaft 19 is fitted to the tip of a part 17 of the valve body. The second support shaft 19 is rotatably supported by the bearing 25.

As shown in FIG. 1, the inert gas supply mechanism 29 supplies an inert gas such as nitrogen (N 2) gas from the gas supply pipes 30, 30 to the second support shaft 19, the bearing 25, and a part of the valve body. 1
7 is periodically supplied so as to be discharged to the flow path 14 from the periphery. The supplied inert gas cools the second support shaft 19, the bearing 25, and the part 17 of the valve body, and also prevents foreign matter such as dust from entering. Similarly, the part 16 of the valve element on the opposite side of the valve element 15, the first support shaft 18, and the bearing 25 are also cooled and dust-purged with an inert gas.

Next, the operation of the hot air control valve constructed as above will be described. First, the hot air control valve 10 is opened and closed via the first support shaft 18 by the drive of the drive motor 21. If the drive motor 21 fails for some reason, it can be manually opened and closed by the manual lever 31.

Since the first support shaft 18 and the second support shaft 19 arranged at both ends of the valve body 15 are cooled by the cooling mechanism 20, seizure or the like occurs even when heated by the high temperature gas. You can operate smoothly without any problems.

FIG. 4 shows a part 17 of the valve body and the second support shaft 1.
9 shows an example in which the stress state at point S near the fitting portion of No. 9 is analyzed by the finite element method. Here, as is clear,
The stress concentration is remarkably alleviated as compared with the conventional cases shown in FIGS. Therefore, the risk of the ceramics cracking due to stress concentration at the fitting portion is greatly reduced.

FIG. 5 is a horizontal cross-sectional view of an essential part showing another embodiment of the present invention, and FIG. 6 is a vertical cross-sectional view of an essential part showing another embodiment of the present invention. Here, the part 16 of the valve body and the part 17 of the valve body are
The tip is fixed by a screw 34 to a first support shaft 32 and a second support shaft 33 having a frog-like shape. Part 1 of valve body
6. A part of the circumference of the tip of the valve body 17 is a flat surface 35.
And is fixed via a cushioning member 36.

With this structure, the screw 34 fixed by the presence of the cushioning member 36 does not cause stress concentration on the valve body 16 and the valve body 17 and reduces the risk of ceramic damage. To do.

In the above embodiments, an example of shrink fitting has been described, but the present invention is not limited to this, and it may be cast, cold fitted, or brazed. Further, the present invention is not limited to the above embodiments, and various design changes can be made based on the technical idea of the present invention.

[0026]

As described in detail above, according to the hot air control valve of the present invention, the flow path of the thermal fluid formed with the refractory heat insulating layer on the inner circumference of the metal casing and the flow path of the thermal fluid. A valve body made of ceramics that can be opened and closed freely,
A part of the valve body symmetrically extending from the peripheral edge of the valve body, first and second support shafts fixed to the part of the valve body and penetrating the casing; Since a drive motor for rotationally driving the first support shaft, a cooling mechanism for cooling the valve body and the support shaft, and an inert gas supply mechanism for dust-purging a part of the valve body and the support shaft are provided, It is possible to prevent the seizure between the first and second support shafts and the bearings, and also to prevent dust and the like from entering through the gap between the support shafts.

Further, since the tip ends of the first and second support shafts are formed in a tapered shape and the fitting stress generated in a part of the first and valve bodies fitted with the first and second support shafts is made uniform, the stress is made uniform. It is possible to prevent stress concentration and prevent cracking of ceramics.

Further, the tip ends of the first and second support shafts are formed in a taper shape, and the inner peripheral tip end which comes into contact with a part of the first and valve bodies is chamfered into a spherical shape to form a valve body. Since the edge portions are not contacted with each other, the ceramics can be prevented from cracking without stress concentration at the fitting portion with the support shaft.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hot air control valve that is an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a hot air control valve that is an embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view showing a fitting portion of the hot air control valve.

FIG. 4 is an explanatory view showing a stress state of a fitting portion of the hot air control valve.

FIG. 5 is a cross-sectional view of essential parts showing another embodiment of the present invention.

FIG. 6 is a vertical sectional view of a main part showing another embodiment of the present invention.

FIG. 7 is an explanatory view showing a stress state of a conventional fitting portion.

FIG. 8 is an explanatory diagram showing a stress state of a conventional fitting portion.

FIG. 9 is an explanatory view showing a stress state of a conventional fitting portion.

[Explanation of symbols]

 10 Hot Air Control Valve 11 Metal Casing 12 Heat Insulating Material 13 Refractory Material 14 Flow Path 15 Valve Body 16 Part of Valve Body 17 Part of Valve Body 18 First Support Shaft 19 Second Support Shaft 20 Cooling Mechanism 21 Drive Motor 22, 23 Short cylinder 24 Guide cylinder 25 Bearing 26 Coupling 27 Taper 28 Inner peripheral tip 29 Inert gas supply mechanism 30 Gas supply pipe 31 Manual lever 32 First support shaft 33 Second support shaft 34 Screw 35 Plane 36 Buffer Element

Claims (5)

[Claims] 1. A flow path for a thermal fluid formed with a refractory heat insulating layer on an inner circumference of a metal casing, a valve body made of ceramics which is openably and closably disposed in the flow path for the thermal fluid, and the valve body. A first and a second support shafts fixed to a part of the base plate and penetrating through the casing; a drive motor for rotationally driving the first support shafts; and a part of the valve body and the support shafts. A hot air control valve comprising: a cooling mechanism for cooling; and an inert gas supply mechanism for dust-purging a part of the valve body and a support shaft. 2. The hot air according to claim 1, wherein the tip ends of the first and second support shafts are formed in a tapered shape, and the fitting stress generated in the valve body fitted with the taper is made uniform. Control valve. 3. The first and second support shafts have tapered tips, and an inner circumferential tip that is in contact with a part of the valve body is chamfered into a spherical shape. 2. The hot air control valve described in 2. 4. The valve body comprises a first cylindrical member,
The hot air control valve according to claim 1, wherein the hot air control valve is fixed to the second support shaft with a screw. 5. The valve body comprises a first cylindrical member,
The hot air control valve according to claim 4, wherein the hot air control valve is fixed to the second support shaft with a screw via a cushioning material.