JPS60237274A - Pressure equalizing device for rotary valve - Google Patents

Abstract

PURPOSE:To effect the pressure equalizing in upstream and downstream of a main valve body as well as the opening and closing of the same by simple one step operation by a method wherein a driving cam is provided at the end face of a valve shaft at a sub valve body side while a follower cam is provided at the end face of the sub valve body at the side of the valve shaft. CONSTITUTION:When the valve shaft 10 is turned through a handle, the driving cam 25, provided at the lower end face of the valve shaft 10, is turned and the cam surface thereof is engaged with the cam surface of the follower cam 48 provided on the sub valve body 33. The follower cam 48 can not be turned by a key 36, therefore, it pushes the sub valve body 33 into the axial direction thereof against a spring 40 to separate it from a valve seat and the pressures in the upstream and downstream of the main valve body 4 are equalized substantially. When the valve shaft 10 is turned further, a key 11 is abutted against the other end 51b of a key groove 51 and the valve shaft 10 is engaged with the main valve body 4 thereby the flow path of the main valve body 4 may be opened.

Description

Detailed Description of the Invention (Subject of the Invention) The present invention relates to a pressure equalizing device for a rotary valve, and more specifically, to a pressure equalizing device for a rotary valve, and more specifically, a pressure equalizing device for a rotary valve, and more specifically, a pressure equalizing device for a rotary valve, which substantially equalizes the pressure upstream and downstream of the valve body when the rotary valve is opened and closed. This invention relates to a device that reduces the rotational torque required for a shaft.

(Prior Art) An example of a conventional device of this type is shown in FIG. This has through holes 104 and 1 in the upstream pipe line 102 and downstream pipe line 103, respectively, which are connected to the valve box 101 of the rotary valve.
05, a pipe 107 having a valve 106 is provided between the through holes 104 and 105, and when the main valve body 109 is opened and closed, the valve 106 is opened to make the pressures upstream and downstream of the main valve body 109 almost equal. , which rotates the valve shaft 111 whose rotational torque is reduced to open and close the main valve body 109. 6113 is a valve seat member, 114 is a valve member for the valve seat member, 1
15 is a support pin. However, when opening and closing the main valve body 109, the valve 106 of the pipe 107 must be opened before rotating the valve shaft 111, resulting in a two-stage operation. This method is complicated and requires a pipe 107 outside the valve N 101, which requires extra space.

(Problem) Therefore, the technical problem of this invention is to make it possible to equalize the pressure upstream and downstream of the main valve body and open and close the main valve body with a simple one-step operation without requiring external piping. do.

(Technical means) The technical means taken to solve the above technical problem are:
A communication hole Z is bored in the main valve body so that the upstream and downstream sides communicate with the main valve body in the valve box, and the sub-valve body that opens and closes this communication hole is axially attached to a guide circle fixed to the main valve body. A biasing member is provided which biases the communicating hole of the sub-valve element in a direction that always closes the communication hole, and a main drive cam which moves the sub-valve element against the biasing member is provided. A driven cam is provided on the end surface of the shaft on the side of the sub-valve body, and a driven cam is provided on the end face of the sub-valve body on the side of the valve shaft, and the two cams are engaged with each other as the valve shaft rotates, thereby moving the sub-valve body. Further, the main valve body is adapted to engage with the valve shaft after the valve shaft has rotated by a predetermined angle.

(Function) When the valve stem rotates in the fully closed state, the main drive cam provided on the valve stem rotates and suddenly engages with the driven force, pressing the sub-valve element against the biasing force of the biasing member.

Due to this suppression, the sub-valve body moves to open the communication hole, and the inlet side and the outlet side in the valve box communicate with each other, and the pressures upstream and downstream of the main valve body become approximately equal.

When the valve stem further rotates, the main valve body engages with the valve stem and is gradually rotated to open the flow path and become fully open. The rotational torque of the valve shaft accompanying the opening of the main valve element is reduced because the sub-valve element opens prior to the opening of the main valve element, so that the differential pressure acting on the main valve element is almost eliminated. Therefore, the main valve body is rotated with a small force. To return from the fully open state to the fully closed state again, the valve stem is rotated in the opposite direction. As a result, the main valve body is engaged with the valve stem and gradually rotates in the opposite direction to close the flow path, reaching a fully closed state.

Thereafter, the main valve body stops moving, and only the valve shaft rotates in the opposite direction by a predetermined angle. During this time, the main drive cam rotates in the opposite direction and is no longer engaged with the driven cam.Then, the secondary valve body moves in the opposite direction to close the communication hole by the biasing force of the biasing member. .

As mentioned above, it is possible to equalize the pressure upstream and downstream of the main valve body and to open and close the main valve body simply by rotating the valve shaft, and since no external piping is required, the installation space can be minimized.

(Special effect) As mentioned above, the main valve body can be opened and closed easily with a one-stage operation of only rotating the valve shaft with reduced rotational torque when opening the valve, so it is possible to easily open and close the main valve body with a one-stage operation, which requires only the rotation of the valve shaft with reduced rotational torque when opening the valve. Since there is no need to perform operations sequentially and accurately, there is no possibility of malfunction, and therefore safe and reliable operation can be expected. In addition, the auxiliary valve element that opens and closes the communication hole is directly moved by the driving cam and driven cam that engage with each other as the valve shaft rotates, without using other operating members, and the rotational force of the valve shaft during movement is reduced. Transmission is absolutely reliable. Furthermore, since the sub-valve element does not rotate and can only move in the axial direction, when the sub-valve element closes the communication hole, the valve seat that the sub-valve element contacts will not be twisted and damaged. It has the advantage of being able to be used for a long period of time as it has almost no oxidation.

(Example) The present invention will be explained in detail below.

In Fig. 2.3, l is a valve box, and an inlet 2 is formed on one side of the valve box 1, and an outlet 3 is formed on the other side. 64 is rotatably arranged inside the valve box 1. The main valve body is provided with a boss portion 5.5a integrally connected to its upper and lower ends, and the boss portion 5 is vertically supported by a bearing portion 6 on the upper wall of the valve box via a bushing 8. The boss portion 5a is rotatably fitted to the lower part of the rotary valve shaft 10 with the key 10, and the boss portion 5a is rotatably attached to the upper end portion of the support pin 13 vertically supported on the bottom wall of the valve box facing the valve shaft 10. It is fitted. The outer peripheral edge of the main valve body 4 is formed into a spherical seat 14 . An annular valve seat member 15 is disposed on the inner wall of the valve box on the side of the outlet 3 from the main valve body 4 in contact with a step 16 formed on the inner wall of the valve box, which is the side wall on the side of the inlet 2. The outer peripheral surface of 15 on the side of the main valve body 4 is formed into a spherical seat 18 that comes into close contact with the spherical seat 14 of the main valve body when the valve is closed. On the inner wall of the valve box on the side of the outlet 3 from the valve seat member 15, a holding member 20 in the shape of a short cylinder is screwed into the valve fil from the side of the outlet 3 of the valve fil, and the end face of the tip of the holding member 20 is disposed on the inner wall of the valve box on the side of the outlet 3. Outlet 3 of member 15
The side wall of 'aJ is pressed down and fixed to the valve box 1 yen.

The lower end surface of the valve shaft 1O is located above the lower end surface of the boss portion 5, and a space 23 is formed between the lower end surface of the valve shaft 10 and the shaft hole 22 into which the valve shaft 10 is fitted. . A driving cam 25 is disposed within a cavity 23 on the lower end surface of the valve shaft 10 . The driving cam 25 includes a cam portion 27 having a spiral cam surface 26 on the lower surface, and a mounting portion 28 that is integrally connected to the cam portion 27 via a stepped portion. They are arranged around the axis of the valve shaft 10 in a substantially fan-shaped shape when viewed from the outside, and are fastened and fixed via bolts 29 and 30 screwed into the mounting portion 28 and the recessed hole 26m of the cam surface 26. Below the main drive cam 25 , a sub-valve body 33 having a flange portion 32 with a large diameter in the space 23 is housed in a bottomed kite tube 35 yen fixed to the lower end surface of the boss portion 5 . The outer circumferential surface is placed in sliding contact with the inner large-diameter surface 35hK so that it can move up and down. The sub-valve body 33 has a key 36 on its outer circumferential surface, and the key 36 is inserted into the insertion hole 37 in the bottom wall of the guide tube 35.
It is engaged with a keyway 38 formed in the key groove 38 and cannot be rotated. A compression spring 40 is interposed between the flange portion 32 of the sub-valve body 33 and the bottom wall of the guide cylinder 35, and constantly biases the sub-valve body 33 upward to prevent the flat ring-shaped sub-valve body It comes in close contact with the valve seat 41. The valve seat 41 is held between a flat washer 44 housed in a current four portion 43 formed on the lower end surface of the boss portion 5 and the upper surface of the guide tube 35 . Further, the sub-valve body 33 is attached to the opposing circumferential edges of the flange portion 32.
has a notch 46 that closes when it comes into close contact with the valve seat 41;
As shown in FIG. 5, the upper end surface of the flange portion 32 has a driven cam 48 which is eccentric to the axes of the sub-valve body 33 and the valve shaft 10. 26 is formed in a helical cam surface 49 that engages with the cam surface 49.

The key groove 51 on the boss portion 5 side that engages with the key 11 has a fourth
The hole shown in the figure is formed with some play in the circumferential direction.

53 is formed to be inclined from the boss portion 5 toward the main valve body 4.
This communication hole 53 has one end open to the cavity 23iC and the other end opened to the front wall of the main valve body 4. When the sub valve body 33 is opened when the main valve body 4 is closed, The inside of the valve box on the inflow port 2 side and the inside of the valve box on the outflow port 3f111 are formed by a through hole 55. provided in the bottom wall of the guide tube 35. They communicate with each other through the guide cylinder 35, the notch 46 of the flange portion 32 of the sub-valve body 33, the cavity 23, and the communication hole 53.

The upper end of the valve shaft 10 protruding from the bushing 8 has a square head 1
0a, and an operating handle (not shown) is coupled to the head 10m to rotate the valve shaft 1O.

57 is an annular flange provided on the valve stem 10, 58 is a retaining ring for preventing the bushing 8 from being pulled out, and 59 to 63 are O-rings.

Next, the operation of the above embodiment will be explained.

To open the valve from the fully closed state shown in Figures 2 and 3, the head 10
When an operation handle is fitted to m and the valve @10 is rotated through this handle, the main drive cam 25 provided on the lower end surface of the valve shaft 10 rotates, and the driven cam 25 provided on the sub-valve body 33 is rotated by the cam surface 26. engages with the cam surface 49 of the cam 48, and at this time the cam rfi
26 and the cam surface 49 are in a spiral shape and are in full contact with each other, and since the driven cam 48 cannot rotate due to the key 36, its wedge action pushes the sub-valve body 33 in the axial direction against the spring 40. This suppression causes the sub-valve body 33 to move toward the flange portion 32.
The outer circumferential surface of the guide tube 35 slides on the inner large-diameter surface of the guide tube 35, moves downward, and leaves the valve seat 41. Therefore, the inlet 2 side and the outlet 3 side of the valve box 1 yen are connected through the through hole 55, the inside of the guide cylinder 35, the notch 46 of the 7-rank part 32 of the sub-valve body 33, the cavity 23, and the communication hole 53. As a result, the pressures upstream and downstream of the main valve body 4 are approximately equal. As shown in FIG. 4, the rotation angle α of the valve shaft lO until the downward movement of the sub-valve body 33 connects the inlet and outlet 2.3 sides in the valve Ml is as follows: The valve shaft 10 and the main valve body 4 are not in contact with each other during this period, and the main valve body 4 does not rotate.

When the valve shaft 10 is further rotated, the key 11 comes into contact with the other end 51b of the keyway 51, and the valve shaft 10 and the main valve body 4 are disengaged, so that the main valve body 4 is gradually rotated to open the flow path. However, when it rotates approximately 90 degrees, it becomes fully open. This main valve body 4
When the valve shaft 10 rotates, the main valve body 4
Since the differential pressure acting on the main valve body is almost eliminated, the rotational torque of the valve shaft 10 is reduced, so that the valve shaft 10 is rotated with a small force.

Next, to change the state from fully open to fully closed, the valve shaft lO is rotated in the opposite direction. At this time, the main valve body 4 is of an eccentric type, and the upstream pressure is acting on the main valve body 4 and it is about to rotate in the closing direction. Therefore, when the valve shaft 10 is rotated in the reverse direction, the key 11
The main valve body 4 is formed on the outer peripheral edge of the main valve body 4 while the main valve body 4 remains in contact with the other end 51b of the keyway 51, that is, in a position where the valve shaft 10 and the boss portion 5 have moved by an angle of β without relative rotation. The spherical seat 14 contacts the spherical seat 1B of the valve seat member 15, thereby closing the flow path. After that, the main valve body 4 stops moving, and the valve stem 10
In other words, the key 11 comes into contact with the one end 51m from the other end 51b of the keyway 51, and during this time the main driving cam 25 rotates in the opposite direction, and the cam surface 26 and the cam surface that are no longer in contact with each other move in the opposite direction. Since the driven cam 48 having the cam 49 moves upward accordingly, the sub-valve body 33 simultaneously moves upward due to the biasing force of the spring 4d and comes into close contact with the valve seat 41, completely blocking communication between the upstream and downstream sides. In this case, since the auxiliary valve body 33 is closed after the main valve body 4 is closed, it is possible to minimize wear and the like on the valve seats 14 and 18 when the main valve body 4 is closed, and also to prevent water hammer. Motion is prevented. β in FIG. 4 indicates the rotation angle of the valve shaft lO required to fully open or fully close the main valve body 4.

In the above embodiments, the shape of the main valve body 4 and the arrangement of the through holes are merely examples, and it goes without saying that other shapes and arrangements having similar functions may be used.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of a conventional example, and Fig. 2 is an actual view of the present invention.
FIG. 3 is an enlarged sectional view of the main parts of the example, FIG. 4 is a sectional view taken along the culm-IV line in FIG. 3, and FIG. 5 is a cross-sectional view taken along the v-v line in FIG. 3. It is a cut sectional view. l...Valve box 2...Inlet 3...Outlet 4...Main valve body 5.5a...Boss part 6...Bearing part lO...Valve stem 11...Key 15... Valve seat member 2o... Holding member 23... Vacant space 25... Main drive cam 26.49... Cam surface 32... 7 rank portion 33.
...Sub-valve body 35...Guide tube 40...Compression spring
41... Valve lock 46... Notch 48... Followed cam 51... Keyway 53... Communication hole Patent applicant Kurimoto Iron Works Co., Ltd. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A main valve body that opens and closes a flow path is rotatably disposed in a valve box, and one end of a rotary valve shaft is fitted to the main valve body, and
In a rotary valve in which the other end of the valve shaft projects outside the valve box and a rotary operation part is provided on this projecting part, the main valve body is connected to the main valve body in the valve box on an upstream side and a downstream side. A communication hole is bored through the communication hole, and a sub-valve element for opening and closing this communication hole is accommodated in a guide cylinder fixed to the main valve element so as to be movable in the axial direction, and the communication hole, which is the sub-valve element, is normally opened and closed. A driving cam is provided on the end surface of the sub-valve body side of the valve shaft to move the sub-valve body against the biasing member of the bracket, and a driven cam is provided on the end surface of the sub-valve body side of the valve shaft. The cams are provided on the side end faces, and the two cams are engaged with each other when the valve shaft rotates, thereby moving the sub-valve body. Further, a pressure equalizing device for a rotary valve, wherein the main valve body engages with the valve shaft after the valve shaft has rotated by a predetermined angle;