JPH0527436U - Valve device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent cracks and damage problems associated with ceramic plugs, which are the plug characteristics of valve plugs, and ensure reliability as a valve. [Structure] A valve plug 9 that opens and closes a seat ring flow hole 5a in a valve body 10 is provided in a guide ring 12 so as to be movable up and down. The valve plug 9 includes a cylindrical plug guide 15 and a base end flange 16a at the stepped portion of the inner hole.
Is made up of a ceramic plug 16 and a plug retainer 17 screwed from the opposite side. A spacer 20 having a contact surface with the plug wider than a contact surface with the plug retainer is interposed between the plug and the plug retainer in the guide ring.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a valve device that controls opening and closing of a seat ring side flow hole by moving a valve plug up and down, and more particularly to a valve device in which a plug characteristic portion of the valve plug is made of a ceramic plug.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, as this type of valve device, those having various structures are known, and for example, a straight through type device as shown in FIG. 4 and an angle type device as shown in FIG. is there. This will be described with reference to the drawings. In FIG. 4, reference numeral 1 denotes a valve body which opens in three directions, and inside the partition wall 2 two compartments 3 and 4 are formed. The partition wall 2 of the valve body 1 is provided with a ring mounting hole 2a which opens in the axial direction, and the seat ring 5 having a through hole 5a which opens into the compartments 3 and 4 in the ring mounting hole 2a. Is fixed. Reference numeral 6 denotes an upper lid having an insertion hole 6a that opens in the axial direction of the valve body 1, and is fixed on the valve body 1 by a stud bolt 7 and a nut 8. Reference numeral 9 denotes a valve plug for controlling the opening / closing of the flow hole 5a, which is provided on the axis of the seat ring 5 so as to be able to move forward and backward, and is attached to the stem 11 for inserting the packing 10 in the insertion hole 6a. A guide ring 12 guides the valve plug 9 and is fixed in the valve body 1.

Further, the reference numeral 1 in FIG. 5 is also a valve main body which opens in three directions, and an upper lid 6 is provided in the upper opening by a stud bolt 7 and a nut 8, and the inside is opened in the axial direction. The seat ring 5 having the through hole 5a is fixed. The flow hole 5a is controlled to be opened and closed by a valve plug 9 provided in a stem 11 penetrating the upper lid 6 and moving back and forth in the axial direction.

By the way, in recent years, in this type of valve device, the plug characteristic portion of the valve plug 9 exposed to the controlled fluid is made of a ceramic material in consideration of wear resistance and corrosion resistance, for example, as shown in FIG. Those having such a structure are known. That is, in this conventional example, the valve plug 9 which is moved forward and backward by the stem 11 in the axial direction is formed at the tip end side of the inner hole 15a of the plug guide 15 which is made of metal and has a substantially tubular shape as a whole. A ceramic plug 16 which is arranged with the base end flange portion 16a locked to the stepped portion 15b and whose front end opens and closes the through hole 5a as a plug characteristic portion, and a base end flange 16a of this plug 16, In the inner hole 15a of the cylindrical plug guide 15, a metal plug retainer 17 is screwed into the inner hole 15a so as to be fixed by pressing it from the non-locking side. The plug retainer 17 is the stem. It was designed to be connected to 11 by screwing. Here, in this conventional example, a case of a cage type in which the seat ring 5 having the above-described through hole 5a and the guide ring 12 for guiding the valve plug 9 are integrally structured is illustrated. In the figure, 13 is a cage window.

That is, a ceramic material is generally expensive, difficult to process, and hard but brittle and easily chipped. For this reason, when the valve plug 9 is used, it is desirable that the entire plug 9 is not formed of a ceramic material, is limited to a minimum vulnerable portion, and can be replaced if necessary. Conventionally, it has been common practice to form only the plug characteristic portion exposed to the control fluid as a plug 16 with a ceramic material, incorporate it into the cylindrical plug guide 15 constituting the valve plug 9 and fix it with the plug retainer 17. It was target.

[0006]

[Problems to be solved by the device]

 However, according to the conventional structure using the ceramic plug 16 as described above, the plug retainer 17 is screwed and fixed in the plug guide 15 with the ceramic plug 16 retained and retained. At this time, the inner end pressing portion 17a of the plug pressing member 17 may come into contact with the end surface of the base end flange 16a of the ceramic plug 16 and rotate it in the plug guide 15. It was the cause of the malfunction.

That is, when the ceramic plug 16 described above rotates in the plug guide 15, the sliding contact portion with the plug guide 15 rubs against each other, or even if the plug 16 does not rotate, the plug 16 does not rotate. The end face of the base end flange 16a and the sliding contact portion at the inner end of the plug retainer 17 rub against each other, and as a result, a minute crack is generated in the sliding contact portion of the ceramic plug 16 and the plug 16 is damaged. However, there is a risk of causing practical problems such as damage, and it is desirable to take some measures that can solve such problems. Of course, as shown in FIG. 6, the sliding contact portion of the metal plug retainer 17 with respect to the ceramic plug 16 is formed to have a shape that minimizes the contact area. However, it is unavoidable that a relative rotational displacement occurs between the plug retainer 17 and the plug 16 or between the plug 16 and the plug guide 15 when the plug retainer 17 is screwed. Must be considered.

In particular, the above-mentioned ceramic plug 16 is exposed to the fluid flow path in the valve device, and when the valve is closed, contact with the seat ring 5, friction, sticking force, etc. When subjected to side force due to turbulence, etc., it is subject to tensile loads and bending loads, which easily cause damage problems, and it is necessary to take measures to prevent the above-mentioned cracks, etc. in order to maintain reliability as a valve. Has been done.

[0009]

[Means for Solving the Problems]

 In order to meet such a demand, the valve device according to the present invention includes a valve plug that opens and closes a flow hole in a valve body, and is attached to a stepped portion of an inner hole of a cylindrical plug guide by a base end flange. As a plug characteristic part to be stopped, a spacer is sandwiched between the ceramic plug and the plug retainer screwed from the non-locking side of the plug guide, and the contact surface with the plug makes contact with the plug retainer. A spacer formed wider than the surface is sandwiched so as to be sandwiched.

[0010]

According to the present invention, the ceramic plug is inserted into the inner hole of the tubular plug guide, the base end flange is locked to the inner hole stepped portion, and the base end flange end surface is The valve plug is constructed by screwing the plug retainer into the plug guide from the non-locking side of the plug with the spacer in between, and fixing it with the tip end abutting against the spacer. To be done.

[0011]

【Example】

 FIG. 1 shows an embodiment of the valve device according to the present invention. In FIG. 1, parts that are the same as or correspond to those in FIG. 6 etc. described above are given the same numbers, and a detailed description thereof is omitted. To do.

According to the present invention, in the valve device as described above, the valve plug 9 for opening and closing the flow hole 5a in the valve body 1 is stepped in the inner hole 12a of the cylindrical plug guide 12. The plug 16 side is provided between the ceramic plug 16 as a plug characteristic portion locked by the base end flange 16a and the plug retainer 17 screwed from the non-locking side of the plug guide 12 to the portion 12b. It is characterized in that it is sandwiched by interposing a spacer 20 formed so that the contact surface thereof is wider than the contact surface with the plug retainer 17 side.

Here, in the spacer 20 described above, when the contact portion 20a with the plug retainer 17 is fixed by screwing the plug retainer 17 to the plug guide 15, the spacer 20 slides and makes a sliding contact, and the minimum required amount. The contact portion 20b with the plug 16 is preferably formed with a large area so as not to slip.

By doing so, when the plug retainer 17 is screwed into the plug guide 15 when the valve plug 9 is assembled, the plug retainer 17 is rubbed against the ceramic plug 16. Further, due to the magnitude of the frictional force due to the contact area difference described above, the rotation of the plug retainer 17 is caused only between the spacer 20 and the spacer 20, and as a result, the rotation of the ceramic plug 16 in the plug guide 15 is prevented. It is possible to prevent the generation of cracks due to the conventional rotation of the plug 16 and eliminate the damage problem. Therefore, with such a configuration, the problem of damage to the ceramic plug 16 due to various acting forces can be minimized, and the reliability as a valve can be improved as compared with the conventional case.

Further, in the above-mentioned configuration, since it is sufficient to obtain the sliding contact state in the contact portion 2a of the spacer 20 with the plug retainer 17, there is an advantage that the other portions can be processed rough. There is also.

Such an advantage is more effective when the contact portion 20a of the spacer 20 with the plug retainer 17 is formed in a spherical shape as shown in FIG. Further, in order to surely prevent the rotation at the contact portion 20b of the spacer 20 with the plug 16 side, instead of the above-described frictional force, in FIG. 3, (a), (b), ( As shown in (c), the abutment portion 20b on the side of the spacer 20 and the end face of the base end flange 16a of the ceramic plug 16 are engaged with each other to prevent rotation. It will be easily understood that the effect can be more enhanced by forming with 31.

It is needless to say that the present invention is not limited to the structure of the above-described embodiment, and the shape, structure, etc. of each part can be appropriately modified and changed. For example, in the valve device, various modifications can be considered as the structure of each part including the structure of the guide ring 12 and the seat ring 5.

[0018]

[Effect of the device]

 As described above, according to the valve device of the present invention, the valve plug is provided with the ceramic plug as the plug characteristic portion locked to the inner hole stepped portion of the tubular plug guide by the proximal end flange, and the plug. A spacer, whose contact surface with the plug is wider than the contact surface with the plug retainer, is interposed between the guide retainer and the plug retainer screwed from the opposite locking side of the guide so as to be sandwiched. Therefore, when the plug retainer is screwed into the plug guide when assembling the valve plug, the friction of the plug retainer with the ceramic plug is eliminated, and the difference in the frictional force due to the contact area causes the plug retainer to Rotation of the plug only between it and the spacer, which prevents the rotation of the ceramic plug in the plug guide, which may cause cracking due to the conventional plug rotation. Prevents loss problem, the effect of excellent on a real that can improve the reliability of the valve.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing an embodiment of a valve device according to the present invention.

FIG. 2 is a schematic view showing a modified example of the present invention.

FIG. 3 is a schematic exploded perspective view showing each of (a), (b) and (c) of another modification of the present invention.

FIG. 4 is a schematic sectional view showing an example of a straight through valve as a suitable valve device to which the present invention is applied.

FIG. 5 is a schematic sectional view showing an example of an angle valve as a suitable valve device to which the present invention is applied.

FIG. 6 is a sectional view of relevant parts for explaining a conventional valve plug structure.

[Explanation of symbols]

 1 valve body 5 seat ring 5a through hole 6 upper lid 9 valve plug 11 stem 12 guide ring 15 cylindrical plug guide 15a inner hole 15b stepped portion 16 ceramic plug 16a base end flange 17 plug retainer 17a inner end retainer 20 spacer 20a contacting part 20b contacting part

Claims (1)

[Scope of utility model registration request] 1. A seat ring which is fixed in a valve body and has a flow opening which opens in the axial direction, and a ceramic plug which opens and closes the flow hole is locked to a stepped portion of an inner hole of a cylindrical plug guide. In addition, in a valve device comprising a valve plug configured by being fixed by a plug retainer from the anti-locking side, a contact between the plug made of a ceramic constituting the valve plug and the plug retainer A valve device characterized in that it is sandwiched and held by interposing a spacer whose surface is wider than the contact surface with the plug retainer.