JPH04107374A - Valve opening indicating device - Google Patents

Abstract

PURPOSE:To improve flow rate regulation precision available when a valve is in a state approximately equal to a full closing state by providing a shaft axially moved along with opening and closing of a valve and a pointer arm rotated according to the axial movement, and increasing rotation of the pointer arm when the valve is in a state approximately equal to a state to fully close the valve. CONSTITUTION:A valve opening closing mechanism 12 is operated and a shaft 20 is axially moved along with movement of a valve body 18. The axial movement is transmitted to a pointer arm 28 through a pin 24 and an oblong hole 30, and the pointer arm 28 is rotated around axle 32 to indicate a graduation 40. Provided the change angle of the pointer arm 28 is theta. a distance between the axle 32 and the pin 24 is A, and a movement amount of the shaft 20 is X, a relation of theta=Tan<-1> (X1A) is established. Namely, the change angle theta is increased according to the movement amount X when the valve body 18 is slightly moved from a fully closed state. Thus, the more a valve is in a state closer to a fully closed state, the more movement of a valve body 18 is read with higher precision, and microregulation is facilitated. Meanwhile, in a full opening region, the change angle theta is decreased according to the movement amount X, but in this region, there is no need for regulation of precision, and the width of a graduation may be narrow.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a valve opening indicating device for moving a pointer indicating the opening state of a valve.

[Prior art]

As shown in FIG. 5, a conventional meter 50 indicating the valve opening has a scale plate 54 affixed with a scale 52 evenly carved in the vertical direction, and is exposed through a window of the scale plate 54. The pointer 56 is moved linearly in the vertical direction to indicate a specific scale. The amount of movement of the pointer 56 is linked to a drive system for opening and closing the valve. For example, in a valve to which a so-called butterfly valve is applied, the pointer 56 indicates the angle when the fully closed state of the butterfly valve is assumed to be 0°. Therefore, the pointer 56 is moved up and down in accordance with the valve opening/closing drive of this drive system, and the current valve opening state can be recognized.

[Problem to be solved by the invention]

However, there is considerable error between the calculated flow rate based on the predetermined opening degree of the valve and the actual flow rate. Since this error in flow rate is approximately constant regardless of the degree of opening or closing of the valve, the error rate when the valve is close to fully open is larger than the error rate when the valve is fully open. For example, the flow rate per unit time with the valve fully open is 100
If the error in CC is 5cc, the error rate is only 5% when the valve is fully open, but when the valve is close to fully open (flow rate per unit time is 10CC), the error rate is 50%.
becomes.

In this way, when adjusting the flow rate in a state close to fully open,
If the conventional meter 50 is used as a basis, compared to adjusting the flow rate when the meter is close to fully open, even an adjustment of one scale will result in a large error when converted into a flow rate, making it impossible to adjust the flow rate with high accuracy. Furthermore, it is possible to increase the number of scales 52 engraved on the scale plate 54 by increasing the amount of movement of the pointer 56, but this increases the number of unnecessary scales (on the fully open valve side), which is not preferable as the meter itself becomes large.

In consideration of the above facts, the present invention aims to provide a valve opening indicating device which is small in size, has a small pointer movement range, and can accurately adjust the flow rate when the valve is nearly fully open.

[Means to solve the problem]

The invention described in claim (1) includes a shaft that is axially moved as the valve is opened and closed, and a pointer arm that is rotatably supported around one end and has a long hole provided along the longitudinal direction. , a pin attached to the shaft and inserted into the elongated hole so as to rotate the pointer arm in response to axial movement of the shaft in the valve opening/closing direction; and the other end of the pointer arm corresponding to a constant axial movement amount of the shaft. It has a scale plate engraved for each movement amount.

The invention according to claim (2) includes a shaft that is axially moved as the valve is opened and closed, and a pointer arm that has a long hole provided along the longitudinal direction and is rotatably supported around one end. , a pin attached to the shaft and inserted into the elongated hole so as to rotate the pointer arm according to the axial movement of the shaft in the valve opening/closing direction; and a pin arranged on the movement locus of the other end of the pointer arm and a unit movement amount. It has a plurality of contacts installed at each location.

[Effect]

According to the present invention, for example, when the valve is fully open, the pointer arm is held perpendicular to the shaft (θ=
0°, where θ is the angle between the shaft and the pointer arm. ). From this state, the shaft is axially moved in response to the opening of the valve.

At this time, the relationship between the axis movement amount
(See Figure 3).

Therefore, the smaller the amount of movement X, the larger the change in angle θ,
The larger the movement amount X, the smaller the change in angle θ. For this reason, the scale width according to the unit movement amount is
The close-to-closed state can be enlarged and fine adjustments can be made.

Here, in the invention described in claim (1), the scale width is smaller as the valve opening approaches the full opening, so the movement range of the pointer arm is not expanded more than necessary, and the valve opening indicating device itself can be made compact. It can be done.

In the invention as set forth in claim (2), the number of contacts provided within a certain movement amount of the shaft increases as the shaft approaches the fully open state;
Signals can be obtained for each minute opening. For this reason, for example, when automatically adjusting the valve opening degree, the closer the valve opening is to full opening, the more finely the adjustment can be performed.

〔Example〕

A valve opening indicating device 10 according to this embodiment is shown in FIGS. 1A and 2B and FIG.

The valve opening indicating device 10 is provided outside the casing 14 of the valve opening/closing mechanism section 12. The valve opening/closing mechanism section 12 has the role of opening and closing a valve body 18 disposed in the pipe line 16, and has a function of opening and closing a valve body 18 disposed in the pipe line 16.
By moving the valve body 18 axially, the valve body 18 is moved to open and close a part of the pipe line 16. The shaft 20 can be moved with high precision by forming a male thread on the shaft 20 and moving the shaft by rotating the shaft, for example, by using a ball screw or the like.

A small diameter portion 2OA is formed at the base of the shaft 20, and a ring 22 is pivotally supported. Therefore, even if the shaft 20 rotates for axial movement, the ring 22 is held without rotating. On the outer periphery of the ring 22,
A female thread 22A is formed, and a male thread 24A formed on a pin 24 is screwed into the pin 24. and extends to the valve opening degree indicating device IO. At the tip of this pin 24 in the extending direction,
A pointer arm 28 is associated.

The pin 24 is housed in an elongated hole 30 formed along the length of the pointer arm 28.

One of the pointer arms 28 is connected to the casing 1 via a shaft 32.
It is pivoted to 4. Therefore, the pointer arm 28 is rotatable about the shaft 32 in the direction of arrow A in FIG. 1(A). Here, the pin 24 of the pointer arm 28 is connected to the elongated hole 3.
0, the movement of the pin 24, i.e.,
It is configured to rotate around a shaft 32 in accordance with the axial movement of the shaft 20.

A sub-casing 34 is attached to the casing 14 so as to include the rotation range space of the pointer arm 28 (see FIG. 1(B)). The sub-casing 34 is dish-shaped and has a fan-shaped window 3 corresponding to the movement locus of the tip of the pointer arm 28.
6 is provided.

Therefore, the tip of the pointer arm 28 can be visually observed through this window 36. A transparent cover 38 is placed on the window 36.
is attached, and a scale 40 is engraved. The engraved width of the scale 40 is determined by the principle shown below.

The pointer arm 28 is perpendicular to the shaft 20 when the valve body 18 fully closes the conduit 16 (horizontal state in FIG. 1(A)). From this state, when the shaft 20 is axially moved in the direction of opening the pipe line 16 by the valve body 18, the pin 24 is moved from one end of the elongated hole 30 to the other end by the cam action of the pin 24 and the elongated hole 30. Accordingly, the pointer arm 28 is tilted at an angle θ. This angle θ is determined by the distance A between the shaft 32 and the pin 24 and the shaft 2
0 (refer to formula (1) described in the section of the invention).

That is, the smaller the amount of movement X, the greater the amount of change in angle θ, and the larger the amount of movement X, the smaller the amount of change in angle θ. The scale width gradually becomes narrower from the fully closed state to the fully open state (see Fig. 3).

Therefore, when the conduit 16 is close to the fully closed region, the scale width is large, making it possible to read the opening degree of the valve body 18 with high accuracy, and when the conduit 16 is close to the fully open region, the scale width is larger than necessary. Rather, the range of rotation of the pointer arm 28 is limited.

The operation of this embodiment will be explained below. - When the pipe line 16 is fully closed by the valve body 18, the pointer arm 28 is held perpendicular to the shaft 20 (angle θ=0).

Here, in order to move the valve body 18, the valve opening/closing mechanism section 12 is operated to move the shaft 20 axially. This movement of the shaft 20 is transmitted to the pointer arm 28 via the pin 24 and the elongated hole 30, and the pointer arm 28 moves the shaft 32 by moving the pin 24 from one end of the elongated hole 30 to the other end. It rotates around the center and points to a scale 40 engraved on the cover 38. The operator can read this and recognize the current state of opening of the pipe line 16 by the valve body 18.

Here, the scale 40 of this embodiment is the pipe line 1 formed by the valve body 18.
6, the scale width is set wide on the side closer to the fully open position, and the scale width is set smaller as the position approaches the fully open position. In this scale assignment, one scale corresponds to a unit movement amount of the shaft 20.

That is, the rotation angle of the pointer arm 28 is determined by the distance A between the shaft 32 and the pin 24 and the amount of movement X of the shaft 20. Therefore, as shown in FIG. 3, it can be seen that the angle of change θ changes greatly with respect to the amount of movement X when the shaft 20 slightly axially moves from the state where the valve body 18 fully opens the pipe line 16 ( θ-tan' (X/A)...(
1)).

Therefore, the movement of the valve body 18 can be read more accurately the closer it is to the fully open position, making fine adjustment easier and reducing errors in the flow rate flowing through the pipe line 16.

On the other hand, in the vicinity of the fully open region of the conduit 16, relatively high precision adjustment is not required. Here, in this embodiment, the scale width in the fully open side region is gradually narrowed, and even if the flow rate error is the same amount, the error rate is low, and the rotation of the pointer arm is reduced in the fully open state. Therefore, the rotation range of the pointer arm 28 does not become larger than necessary, and the accuracy can only be increased in the region near fully closed, which requires high-precision adjustment, so the opening degree indicating device 10 itself can be made compact. I can do it.

In addition, in this embodiment, the accuracy of reading the opening degree by the pointer arm 28 can be improved, but as shown in FIG. It is possible to increase the number of contacts that can be accommodated within one scale in the region near fully closed, for example, when the shaft 2
Even when automatically controlling the movement of zero, the flow rate flowing through the conduit 16 can be adjusted with high precision.

In this embodiment, the opening degree of the pipe line 16 by the valve body 18 is set so that the pointer arm 28 and the shaft 20 are perpendicular to each other when the valve body 18 is fully closed. Fine adjustment around this arbitrary opening degree can be performed.

〔Effect of the invention〕

As explained above, the valve opening degree indicating device according to the present invention includes:
It is small, the movement range of the pointer is small, and it has the excellent effect of being able to accurately adjust the flow rate when the valve is close to fully open.

[Brief explanation of drawings]

FIG. 1(A) is a front view showing the inside of the valve opening degree indicating device according to the present embodiment, FIG. 1(B) is a front view of the sub-insulator, and FIG. 2 is a left side view of FIG. 1. Fig. 3 is a characteristic diagram showing the change in angle with respect to the amount of shaft movement, Fig. 4 is a front view when a contact point is provided on the movement locus of the pointer arm, and Fig. 5 is a front view of a conventional opening indicating device. be. DESCRIPTION OF SYMBOLS 10... Valve opening degree indicating device, 20... Shaft, 24... Pin, 28... Pointer arm, 30... Long hole, 40... Scale.

Claims (2)

[Claims] (1) A shaft that is moved as the valve opens and closes;
A pointer arm is provided with a long hole provided along the longitudinal direction and is rotatably supported around one end, and the pointer arm is attached to the shaft and rotates in accordance with the axial movement of the shaft in the valve opening/closing direction. A valve opening indicating device comprising: a pin inserted into the elongated hole; and a scale plate engraved for each amount of movement of the other end of the pointer arm corresponding to a certain amount of axial movement of the shaft. (2) a shaft that is moved as the valve opens and closes;
A pointer arm is provided with a long hole provided along the longitudinal direction and is rotatably supported around one end, and the pointer arm is attached to the shaft and rotates in accordance with the axial movement of the shaft in the valve opening/closing direction. A valve opening indicating device comprising: a pin inserted into the elongated hole; and a plurality of contacts arranged on a movement locus of the other end of the pointer arm and installed for each unit movement amount.