JPH0641022Y2 - Ball valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a ball valve, and more particularly to a ball valve designed to reduce rotational torque.

[Conventional technology]

As shown in FIG. 6, a ball valve generally used in the past has a pair of opposed passages communicating with a valve chamber 51 of a valve body 50.
52, the seat rings 53 are inserted into both passages 52, and each seat ring 53 is inserted into the ball valve body 54 in the valve chamber 51.
Ring-shaped leaf spring 58 at the rear end of each seat ring 53.
The retaining ring 55 is fixed with the interposition of, and the seat ring 53 is pressed against the ball valve body 54 by the spring force of the leaf spring 58.

In addition, in the figure, 56 is a bonnet that closes the open portion of the valve body 50, and 57 is a valve rod that is integral with the ball valve body 54.

[Problems to be solved by the invention]

In the ball valve having the above structure, since the seat ring 53 is constantly pressed against the outer peripheral surface of the ball valve body 54, sliding resistance when the ball rod 57 is opened and closed by rotating the valve rod 57 is reduced. There is a problem that it is large and the rotation torque is large.

Therefore, an object of the present invention is to provide a ball valve having a structure with a small rotational torque without impairing the sealing function of the seat ring.

[Means for solving problems]

In order to solve the above problems, the present invention forms a pair of opposed passages through a valve body in a valve body, mounts a seat ring inside each passage, and inserts a ball valve element into the valve chamber, In a ball valve in which a valve rod for rotating the ball valve element is projected to the outside of the valve body, the seat rings are slidably mounted in the axial direction of the passages, and the seat rings are engaged with both sides of the valve rod. The auxiliary cam plate which is provided with a joint portion and rotates inside the engaging portion and the main cam plate with a flange edge which rotates outside the engaging portion are respectively provided integrally with the valve rod. An auxiliary cam plate projection that engages with the inside of the engaging portion to move the seat ring outward is provided, and engages the outside of the engaging portion with the flange of the main cam plate to move the seat ring inward. The main cam plate protrusion that moves the Provided at a position to be engaged with the engagement portion, in which the auxiliary cam plate projection has a configuration provided at a position displaced from each other by a required angle of rotation from the main cam plate projection.

[Action]

When the ball valve element is in the closed state, the main cam plate projection engages with the outside of the engaging portion of each seat ring, thereby moving each seat ring inward and pressing it against the ball valve element,
Performs sealing action. When the valve rod is rotated to rotate the ball valve element by the required angle in the valve opening direction, the auxiliary cam plate protrusion engages with the inside of the engaging portion of each seat ring, which moves the seat ring outward. Let the ball move away from the valve body. When the ball valve element is rotated from the open state to the valve closing direction, the main cam plate projection engages with the outside of the engaging portion of each seat ring to move each seat ring inward, Press it down.

〔Example〕

1 to 5 show the ball valve of the embodiment. In the ball valve of the embodiment, a valve body 2 is provided in a valve body 1, and two passages 3 open to the outside are provided at positions symmetrical to the center of the valve chamber 2. A step portion 4 is formed inside each passage 3, and a seat ring 5 is attached to the step portion 4. The front surface of each seat ring 5 is brought into contact with both sides of the ball valve element 6 inserted into the valve chamber 2. With the front end surface of each seat ring 5 in contact with the ball valve element 6, there is a gap 7 between the rear end of each seat ring 5 and the step portion 4, and within each gap 7 each seat ring 5 can slide in the direction of its central axis.

The ball valve body 6 is formed with a valve rod 9 penetrating the bonnet 8 and protruding outward, and a bottom valve rod 10 is provided on the opposite side of the valve rod 9 so as to project. An open portion of the valve body 1 facing the valve rod 10 is closed by a bottom lid 11.

The above-mentioned valve rod 9 and bottom valve rod 10 have a main cam plate 12 respectively.
Also, the auxiliary cam plate 13 is attached, and the engaging portion 14 protruding from the seat ring 5 and the auxiliary cam plate 13 can be engaged and disengaged by the rotation of the valve rod 9. Since the engagement / disengagement mechanism has the same structure on both the valve stem 9 side and the bottom valve stem 10, only the structure on the valve stem 9 side will be described below.

The main cam plate 12 and the auxiliary cam plate 13 have boss portions 15 and 16 respectively (see FIG. 2), and the boss portion 16 of the auxiliary cam plate 13 is connected to the valve rod 9
The auxiliary cam plate 13 by inserting the boss portion 15 of the main cam plate 12 around the boss portion 16 of the auxiliary cam plate 13.
Put the main cam plate 12 on top of it. Both boss portions 15 and 16 are attached to the valve rod 9 by a common screw 17.

The auxiliary cam plate 13 has a disk shape as a whole, and has a notch surface 18 formed at a centrally symmetrical position on the outer peripheral surface thereof (see FIG. 3). The cutout surface 18 is formed on the inner side of the cutout circular engaging portion 14 provided on the outer peripheral portion of the front end surface of the seat ring 5 when the ball valve body 6 is in the closed state (FIGS. 1 and 3). It faces a flat surface. When the auxiliary cam plate 13 rotates together with the main cam plate 12 in the valve opening direction (see the arrow a in FIG. 4), the inside of the engaging portion 14 is rotated so that one end 19 of the notch surface 18 has an oval shape. Upon hitting the flat portion of the joint 14, each seat ring 5 is retracted (see arrow b in FIG. 4).

As described above, since the one end 19 of the cutout surface 18 comes into contact with the flat surface of the cutout circular engaging portion 14 to retract the seat ring 5, the one end 19 is generally Specifically, it is only necessary that the protrusions project at the same height. In the “claim for utility model registration”, this is collectively referred to as the “auxiliary cam plate protrusion”.

In addition, the missing circular engagement portion 14 protruding from the seat ring 5 is
A member separate from the seat ring 5 may be fixed to the seat ring 5.

On the other hand, the main cam plate 12 is also formed in a disc shape, and has a downward flange edge 20 formed on the outer periphery thereof. The inner radius of the brim edge 20 is formed so as to be larger than the maximum distance from the center of the valve rod 9 of the above-mentioned circular lack engagement portion 14. A small protrusion 21 is formed on the brim edge 20 at a position symmetrical with respect to the center, and the small protrusion 21 abuts on the top of the outer circular arc surface of the missing circular engagement portion 14 in the valve closed state.

In the "claim for utility model registration", the small protrusions 21 are collectively referred to as "main cam plate protrusions". Small projection above
The positional relationship between 21 and the one end portion 19 of the auxiliary cam plate 13 is
As shown in FIG. 3, the required angle θ around the valve rod 9
Is. This angle θ is such that the one end portion 19 has a cutout surface when the valve is opened.
It is set to the smallest angle within the range where it does not touch 18.

The ball valve of the embodiment has the above configuration, and its operation will be described below.

In the valve closed state, as shown in FIG. 1 and FIG.
The small protrusion 21 of the main cam plate 12 is a circular engaging portion of the seat ring 5.
The seat ring 5 is moved inward to come into contact with the apex of the outer surface of 14, and is brought into close contact with the ball valve body 6.

When the ball valve body 6 is rotated in the valve opening direction (see the arrow a in FIG. 4) by the angle θ by rotating the valve rod 9 from the above valve closed state, one end 19 of the cutout surface 18 is removed. Seat ring 5
It hits the inner flat surface of the missing circular engaging portion 14. For this reason, each seat ring 5 moves outward, separates from the ball valve element 6, and the friction acting on the ball valve element 6 is reduced.

In the case shown in the figure, since the outer peripheral surface between the two notched surfaces 18 of the auxiliary cam plate 13 is a circular arc surface 22, the circular arc surface 22 of the auxiliary cam plate 13 becomes the inner flat surface of the circular truncated engaging portion 14. Because it slides into contact,
When the valve is opened (see FIG. 5), the seat ring 5 is prevented from moving inward.

Further, when the valve rod 9 is rotated in the valve closing direction (see the arrow b in FIG. 5) from the valve opened state shown in FIG. 5, the small projection 21 of the main cam plate 12 is moved.
Hits the outer arc surface of the missing circular engaging portion 14, so that the seat ring 5 is moved inward, and when the small projection 21 reaches the top of the engaging portion 14, the seat ring 5 is brought into close contact with the ball valve body 6. (Fig. 3).

The cam mechanism on the side of the bottom valve rod 10 may be omitted.

[Effect of device]

As described above, the present invention relates to the interrelation between the main cam plate projections and the auxiliary cam plate projections respectively provided on the main cam plate and the auxiliary cam plate integrated with the valve rod, and the engaging portion provided on the slidable seat ring. Since the seat ring is pressed against the ball valve body by closing due to the deactuation, a reliable seal can be achieved.
Further, in both cases of opening and closing the valve, the seat ring is separated from the ball valve body, so that there is an effect that the seat ring can be operated with a small rotational torque.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment, FIG. 2 is a partial sectional perspective view showing a part of the same, and FIGS. 3 to 5 are explanatory views of the operation of the same. FIG. 6 is a sectional view of a conventional example. 1 ... Valve body, 2 ... Valve chamber, 3 ... Passageway, 4 ... Step, 5 ... Seat ring, 6 ... Ball valve element, 7 ... Gap, 8 ... Bonnet, 9 ... Valve Rod, 12 ... main cam plate, 13 ... auxiliary cam plate, 14 ... engaging part, 18 ... notch surface, 19 ... one end, 20 ... brim edge, 21 ... small protrusion.

Claims (1)

[Scope of utility model registration request] 1. A pair of opposed passages are formed in a valve body through a valve chamber, a seat ring is attached to the inside of each passage, and a ball valve element is inserted into the valve chamber to rotate the ball valve element. In a ball valve in which a valve rod is projected to the outside of the valve body, each seat ring is slidably mounted in the axial direction of each passage, and engaging portions are projectingly provided on both sides of the valve rod of each seat ring. An auxiliary cam plate that rotates inside the engaging portion and a main cam plate with a brim edge that rotates outside the engaging portion are provided integrally with the valve rod, and the auxiliary cam plate is engaged inside the engaging portion. An auxiliary cam plate projection for moving the seat ring outward is provided, and a main cam plate projection for engaging the outside of the engaging portion with the flange edge of the main cam plate to move the seat ring inward is provided. The main cam plate protrusion is provided at a position where it engages with the engaging portion when the valve is closed. Only, a ball valve is characterized by providing the auxiliary cam plate projections at positions displaced from each other by a required angle of rotation from the main cam plate projection.