JPS60263784A - Control valve using pulse motor - Google Patents

Abstract

PURPOSE:To enhance both range ability and control resolution by using a pulse motor, a worm speed reduction mechanism and a screw mechanism. CONSTITUTION:When a pulse motor 3 is rotated in the normal and reverse directions the turning force is transmitted through a coupling 17, a driving shaft 15, a worm 13 of a worm speed reduction mechanism 4, a worm wheel 14 and a driven shaft 16 to a ball guide nut 18 of a screw mechanism 5. When the ball guide nut 18 of the screw mechanism 5 is rotated, as a coupling member 21 is detected by a detent mechanism 22 in such a manner as to freely elevate, a screw rod 19 is elevaged, so that the coupling member 21, a valve rod 11 and a valve body 10 are detented and elevated. The valve body 10 is brought into contact with and separated from a valve seat 8 of a valve casing 9, whereby a main body 2 of a valve is opened and closed to control flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a control valve used in devices and equipment that handles fluids to precisely control the flow rate of the fluid to be handled.

(Prior Art) Conventionally, as this type of control valve, for example, a tire flam type control valve that uses air pressure to drive the valve, a control valve that uses an inductor motor, etc. are known.

However, the control performance of any control valve is
In addition to rangeability being a critical requirement, the control resolution was also small, making it impossible to control the flow rate of the fluid handled with ultra-small precision.

Range ability, as is well known, refers to the ratio of the maximum controllable flow rate to the minimum flow rate, and the larger this ratio is, the larger the controllable flow range becomes.

On the other hand, the term control resolution is used in the present invention to refer to control resolution.
It is defined and used as the quotient obtained by dividing the range of liquid fluid that can be controlled by the minimum flow rate m that can be controlled. That is, (611 inn 1-
r11' Express how many parts the functional flowmeter range can be divided into.-J
If this control resolution is large, it means that the controllable minimum l is small compared to the flow rate range that can be controlled. Low flow rate 1: Allows fine control over the area.

Control resolution has a close relationship with the above-mentioned range ability. Expand your range ability to make low '(1 do i)
Even if diversion control is made possible in a wide Ijj area with a wide range of people flow, if the control resolution remains small, the minimum flow rate unit that can be controlled is large, making fine control in low flow areas difficult. It means not being able to.

This will be specifically explained using numerical values.

For a control valve with a controllable flow rate range of 10 to 200'/l-1r and a controllable minimum flow unit of 0.5'/T (r), the range ability is 20 and the control resolution is It becomes 380.

Even if the rangeability becomes 1.000 and the controllable flow rate range widens to 0.2 to 200'/T-(r), if the control resolution remains 380, the minimum controllable flow rate unit is Since it is approximately 0.531A4r, fine control in the low flow rate region close to O-2l?/l-Ir is actually impossible.

Therefore, if the control resolution could be increased to 10.000, the minimum controllable flow rate unit would be approximately 0.02'/l-1.
Since it is r, fine control is possible even in the low flow rate range as mentioned above. Therefore, when increasing the range ability, it is necessary to simultaneously increase the control resolution.

The term "unit sensitivity" is well known, but since it focuses only on the movement of the valve stem, it cannot be used as a factor for evaluating the control performance of the control valve of the present invention, which has characteristics in the drive section. It's not appropriate.

Currently, the range ability of the most commonly used tire flamm control valve that uses air pressure is about 20 to 40, so if the controllable flow rate range is wide, it is recommended to use a combination of multiple control valves. Otherwise, it was necessary to take measures such as replacing the valve body in accordance with changes in the flow rate range. Furthermore, in this type of control valve, the control resolution is 400
It is small, about ~600, and has not been able to perform the minute and precise control required especially in the low flow rate range.

(Problems to be solved by the invention) The present invention was devised in view of the above-mentioned problems and to solve them, and its purpose is to dramatically improve both rangeability and control resolution. It is an object of the present invention to provide a control valve which is enlarged in size and is capable of controlling the flow rate of a handled fluid in an ultra-fine manner and with high precision over a wider range than before.

Means for Solving Problem C) The control valve of the present invention includes a valve body that can control the handled fluid by imitating a movable valve stem, a pulse motor supported by the valve body, and a pulse motor linked to the pulse motor. and a screw mechanism that is interposed between the worm reducer ff/; and the valve stem of the valve body and converts rotational motion into linear motion. There are characteristics.

In other words, by using a pulse motor, a worm reducer (14), and a screw mechanism, the valve stem of the valve body can be moved very finely.

(Function) When the pulse motor is driven to rotate, its rotation is reduced by the worm reducer connected to it]74, and then the rotary motion is converted into linear motion by the screw mechanism, and the valve stem is moved. .

That is, when the pulse motor is rotated in the forward and reverse directions, the valve body provided on the valve stem is brought into contact with and unseated from the valve seat of the valve box, thereby allowing passage of the fluid to be handled and control of the flow rate.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal sectional front view showing the structure of a control valve according to an embodiment of the present invention. Fig. 2 is a plain drawing of Fig. 1 drawn from ■-■.

The main parts of the control valve 1 include a valve body 2, a pulse motor 3, a worm reduction mechanism 4, and a screw mechanism 5.

The valve body 2 is capable of controlling the flow rate of the fluid to be handled, and includes a valve body 9 having a valve seat 8 formed in the middle of a flow path communicating with the inlet 6 and the outlet 17, and the valve body 9. It consists of a valve body 10 that seats on and leaves the valve seat 8 of a box 9, and a valve rod 11 that is provided on the valve body 10 and is movably supported while being knurled to the valve body 9. In this example, it is a needle valve. A model with linear characteristics is used.

The pulse motor 3 is supported by the valve body 2,
Specifically, it is provided through a box-shaped housing 12 attached to the upper part of the valve body 2.

As is well known, Pulsmoke 3 has no feedback and can stop rotating at a predetermined angle with high precision.The total rotation angle is proportional to the total number of input pulses, and the rotation speed is proportional to the input pulse per unit time. It is proportional to the number of pulses.

In this example, a device that rotates by 1.8 degrees per pulse (that is, one rotation per 200 pulses) is used.

The worm deceleration mechanism 4 is connected to the pulse motor 3 and can decelerate its rotation, and the worm 1 consists of a worm 13 and a worm wheel 14 meshing with the worm 13.
3 is wedged to a horizontal drive shaft 15 rotatably supported by the housing 12, and the worm wheel 1
4 is wedged and stacked on a vertical driven shaft 16 which is also rotatably supported by the housing 12, and the drive shaft 15 and the output shaft of the pulse motor 3 are linked by a coupling 17.

The screw mechanism 5 connects the worm reduction mechanism 4 and the valve stem 1 of the valve body 2.
1 to convert rotational motion into linear motion, and in this example, a hole screw consisting of a ball guide nut 18 having a large number of holes therein and a threaded rod 9 screwed into the ball guide nut 18. 20 is used, whole chi 1 gun nut 1
8 is attached to the driven shaft 16 and a threaded rod 19
is connected to the valve stem 11 via the connecting member 2J.

The screw pitch of the pole screw 20 is 1.5m+n,
The lift amount of the valve body 10 is set to 8 m.

Thus, the screw mechanism 5 includes a rotation stopper mechanism 22, which includes a vertically elongated guide section 23 formed on the connecting member 21, and a shaft provided on the housing 12 to sandwich the guide section 23 from both sides. It consists of a pair of guide rollers 24, and the connecting member 21
It has the function of allowing the vertical movement of the cylinder and disabling rotational movement.

Next, in such a configuration, the action is repeated.

When the pulse motor 3 is rotated in the forward and reverse directions, the rotational force is generated from the cup link 17 → the drive shaft I5 → the worm 13 of the worm reduction mechanism 4 → the worm wheel 14 → the following driving shaft 16
The signal is transmitted to the ball guide nut 18 of the screw mechanism 5 through.

When the ball guide nut 18 of the screw mechanism 5 rotates, the connecting member 21 is prevented from rotating so that it can move up and down by the rotation preventing mechanism 221, so the screw rod 19 moves up and down, and the connecting member 21, the valve stem 11, and the valve The body 1o moves up and down while being stopped from rotating.

Therefore, since the valve body 1o is seated and unseated with respect to the valve seat 8 of the valve box 9, the valve body 2 can be opened and closed, and the flow rate can be controlled as well as the passage of the fluid to be handled.

As a result of experiments conducted on the control valve 1 of this embodiment, the controllable flow rate range was approximately 0155 to 175'AI.
r, the minimum flow rate unit that can be controlled is approximately o, oi'/1
-1 +-. Therefore, the range ability is approximately 1
．． 130, control resolution is approximately 1'7.500 Te, F,
It was.

In addition, as a result of similar experiments on the tire plum type waterfall control valve that uses air pressure, which is currently the most commonly used,
The controllable flow rate range was about 4.6 to 150'/Hr, and the minimum controllable flow rate unit was about 0.27'/Hr. Therefore, the rangeability was approximately 33, and the control resolution was approximately 540.

However, in the control valve 1 of this embodiment and the tire flam type control valve, only the driving part is replaced, and both have a MaxGV value of 0.0.
035, ΔP is 100 yen ate experiment.

Therefore, when compared with the diaphragm type control valve that uses pneumatic pressure, which is currently most commonly used, the control valve 1 of this embodiment is about 34 times better in range ability and about 32 times better in control resolution. It turned out that there was.

Although the valve body 2 is of the needle valve type in the previous embodiment, the present invention is not limited to this, and various types and structures may be adopted.

In the previous embodiment, the pulse motor 3 has a pulse speed of 1.8
Although a type that rotates many degrees is used, the configuration is not limited to this, for example, a type that rotates the sail by 9 degrees with an I pulse may be used.

In the previous embodiment, the pole screw 2o was used for +R a '185 due to hysteresis, etc., but it is not limited to this, and it may be simply a screw rod that is screwed together. The screw pitch is also limited to 1.5 mm, and can be selected to an appropriate value.

In the previous embodiment, the screw mechanism 5 is connected to the ball guide nut 1.
8 to the worm wheel 13 side, and the threaded rod 19 to the valve rod 11.
This is limited to whether they are linked to each side, or vice versa.

In the previous embodiment, the rotation prevention mechanism 22 included in the valve mechanism 5 is interposed between the housing 12 and the connecting member 21, or is limited to this, and allows the valve stem 1 to move up and down while being prevented from rotating. Therefore, it can be positioned and structured as appropriate.

(Effects of the Invention) As described above, according to the present invention, the following various effects can be achieved.

(1) A small device that dramatically increases both rangeability and control resolution by more than 30 times, and allows handling of fluids, especially the flow rate, over a wider range than before with ultra-fine and high precision control. can be controlled.

As a result, the controllable flow rate range that conventionally required 3 to 5 control valves can now be done with one control valve, which is extremely economical, and the flow rate of the fluid to be handled changes frequently. It is extremely effective when adopted in plants that produce a small number of different products.

(2) Since a worm reduction mechanism and a screw mechanism are provided, the rotational force of the pulse motor can be increased and transmitted to the valve body, and it can be used even when the pressure of the fluid to be handled is high.

(3) Since a worm reduction mechanism is provided, even if the pressure of the fluid being handled fluctuates, the valve body is held at a predetermined opening position, and no reversing force is transmitted to the pulse motor.

Therefore, failures can be prevented from occurring, and stable and extremely accurate flow rate control can be performed at all times.

(4) Since the structure does not utilize air pressure, it is extremely effective in places where anaerobic conditions are imposed.

(5) The pulse motor can be controlled directly by a computer, which facilitates automation.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing the structure of a control valve according to an embodiment of the present invention. FIG. 2 is the ■-■ transverse plane rotation of FIG. 1. l... Control Valve 2... Valve body 3 Pulse motor 4 Worm reduction mechanism 5... Screw mechanism Fig. 7 1 2nd diagram system Tsukuda valve sho Main body pulse motor

Claims (1)

[Claims] A valve body that is equipped with a movable valve stem and can control handled fluid, a pulse motor supported by the valve body, and a worm reduction mechanism that is connected to the pulse motor to reduce its rotation. A control valve using a pulse motor, characterized in that it is comprised of a screw machine 11 which is interposed between a valve stem of a valve body and converts rotational motion into linear motion.