JPH0651842A - Flow controller - Google Patents

Abstract

PURPOSE:To easily manufacture the flow controller for opening/closing fluid and adjusting flow by omitting an adjustment process at the time of manufacture for detecting the close position of a valve. CONSTITUTION:This device is composed of 1st and 2nd valve elements 22 and 24, valve shaft 6, motor 12, flow sensor 13, flow calculation part 14, flow stop detection part 30 and valve opening time motor control part 31 to control the motor 12 at the time of opening the valve while receiving the signal of the flow stop detection part 30. At the time of opening the valve, the motor 12 is driven by the feedback control part 15 at velocity corresponding to set flow (a) and operated so as to prevent the overshoot of flow caused by the delay of flow detection at the time of reducing the set flow, and the control at the time of opening the valve can be stably performed in the shortest time corresponding to the set flow. The motor 12 is stopped by surely detecting the close position of the valve by detecting the stop of a pulse signal from the flow sensor 13. Since the adjustment process at the time of manufacture is omitted and further a position detector can be omitted, the device can be minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate control device for keeping hot water and water out of a bathroom, washbasin, kitchen, etc., and for obtaining a desired flow rate.

[0002]

2. Description of the Related Art Conventionally, a flow rate control device of this type is shown in FIG.
There was something like that.

A valve seat 4 is provided on the body 1 between a flow passage inlet 2 and a flow passage outlet 3, and a valve shaft 6 and a valve body 5 which are loosely fitted and connected to a valve body 5 facing the valve seat. A spring 7 for urging is provided. The thread portion 8 of the valve shaft 6 is screwed into the rotation straight line conversion screw 9 of the body 1. Further, the valve shaft 6 is a gear 10
And a motor 12 that is rotationally driven via a gear 11. The DC motor 12 is controlled by the flow rate sensor 13, the flow rate calculation unit 14, and the feedback control unit 15 according to the difference between the flow rate signal from the flow rate calculation unit 14 and the set flow rate. 16 is a cam integrated with the gear 11 and is a position detector 17
Have.

FIG. 5 shows the characteristics of the feedback control unit 15. The motor 12 is driven at a speed proportional to the flow rate error which is the difference between the flow rate signal and the set flow rate, and the valve shaft 6 is moved left and right to open the valve body 5. Alternatively, when the flow rate signal is adjusted to the close direction and the flow rate signal substantially matches the set flow rate, the motor 12 is stopped and the flow rate is adjusted to be equal to the set flow rate. In the range where the flow rate error is small in FIG. A, the speed is proportional to the error, but in the range where the flow rate error is above a certain level in FIG. B, the motor speed is constant because the speed of the motor 12 is limited.

[0005]

However, the conventional structure as described above has the following problems.

The position detector 17 detects the closed position corresponding to the cam 16 of the gear 11. Position detection is performed because component variations such as variations in the dimensions of the valve seat 4, the valve body 5, and the valve shaft 6, the fitting relationship between the screw portion 8 and the rotation straight line converting portion 9, and the fitting relationship between the gear 10 and the gear 11 are accumulated. In order for the device 17 to detect the D position in FIG. 6, it becomes necessary to adjust the operating point of the position detector 17 one by one when manufacturing the device. For example,
The gear 10 was removed from the valve shaft 6, the gear 11 was moved to the closing detection position of the position detector 17, and the point where the valve body 5 contacted the valve seat 4 at point C in FIG. Later,
Further, the valve shaft 6 is moved to the right by an amount corresponding to E in FIG. 6, and thereafter, the gear 10 is engaged with the gear 11 to be connected to the valve shaft 6 for adjustment. As described above, in the conventional example, since it is necessary to adjust the closing detection positions one by one in a complicated process, manufacturing is time-consuming and costly.

The present invention is intended to solve the above problems and to realize a flow rate control device which can be manufactured easily without adjustment by omitting the adjustment step.

[0008]

In order to achieve the above-mentioned object, the present invention is provided with a valve closing time control unit for detecting the stop of the signal of the flow rate sensor and stopping the motor.

[0009]

With this construction, the motor is stopped by confirming the stop of the signal of the water amount sensor at the position where the valve body is closed when the valve is closed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the first inlet 18 into which hot water flows
A second inlet 19 through which water flows and one outlet 20,
Between the first inlet 18 and the outlet 20, the first valve seat 21 and the first
And a second valve seat 23 and a second valve body 24 are provided in the flow path body 1 between the second inlet 19 and the outlet 20, respectively. The first valve body 22 and the second valve body 24 are respectively provided with a first spring 25 and a second spring 26 that bias in the closing direction, and the valve shaft 6 is the second valve body 24.
Is slidably passed through, and its tip is slidably connected to the hole 27 of the first valve body 22, and further abuts on the second valve body 24 by a retaining ring 28. An O-ring 29 is provided in the penetrating portion between the second valve body 24 and the valve shaft 6 to seal the sliding portion. A flow rate sensor 13 is provided at the outlet 20, and a signal of the flow rate sensor 13 has its period measured by a flow rate calculation unit 14 to calculate a flow rate signal. This flow rate signal is compared with the set flow rate signal, and the feedback control unit 15 drives the motor 12 to rotate the valve shaft 6 by the gear 11 and the gear 10 and the threaded portion 8 of the valve shaft 6 and the rotary linear conversion screw 9 to drive the valve shaft. 6 is driven in the thrust direction. The flow stop detector 30 works in conjunction with the flow calculator 13 to detect the stop of the pulse signal of the flow sensor 13.
When the valve is closed, signals from the hot water discharge / stop switch 32, the water discharge / stop switch 33, and the flow rate stop detection unit 30 are input to the motor control unit 31. When the valve is closed, the switch 12 drives the motor 12 instead of the feedback control unit 15. To do.

With the above construction, when the hot water discharge / stop switch 32 is operated and hot water is being discharged, the valve shaft 6 is driven to the left and the first valve body 22 is opened, and the feedback control unit 15 is operated by the signal from the flow rate sensor 13. Controls the flow rate equal to the set flow rate.

FIG. 2 is a characteristic diagram of the motor speed and the flow rate when the valve is closed. When the tapping / stopping switch 32 is operated to instruct the valve closing, the valve closing motor control unit 31 switches the switch 34 to change the state. At time F, the motor 12 is driven in the closing direction at the speed v1. The first valve element 22 moves to the right to reduce the flow rate and the pulse signal interval of the flow rate sensor 13 becomes longer. At the time of G and H when the decrease in the flow rate is detected by the flow rate calculation unit 14, the valve closing motor control unit 31 sets the motor speed to v2 according to the flow rate.
It is gradually lowered to v3 so as not to overshoot the closed position. The motor speed is further reduced to v4 at time I when the flow rate calculation unit 14 detects T1 corresponding to a flow rate equal to or lower than the minimum operating flow rate of the flow rate sensor 13, and the flow rate stop detection unit 30 passes the time T2 longer than T1 from time I. Wait for the flow sensor 1
After confirming that the pulse signal of No. 3 does not come, it is determined that the flow rate is stopped, and the valve closing motor control unit 31 sets the motor speed to zero and stops the motor 12. If the flow rate K, which is a sufficiently small flow rate, is confirmed at the time point I, and the moving distance of v4 × T2 is set to be equal to or more than the opening degree of the valve body 22 corresponding to the flow rate K, the first time point at the time point L until the time point J is reached. It is ensured that the valve body 22 abuts the first valve seat 21. Since v4 is sufficiently low speed, the overshoot amount can be suppressed small.

On the other hand, when the water discharge / stop switch 33 is operated, the valve shaft 6 is driven to the right, the first valve body 22 abuts on the first valve seat 21, and the valve shaft 6 has a hole 27. Sliding to the right causes the stop ring 28 to push open the second valve body 24
The water at the inlet 19 is supplied to the outlet 20 and the flow rate is feedback-controlled. When the water out / on switch 33 is operated again to instruct to close the valve, the movement direction is opposite to that in the case of the above hot water, and the valve closing operation is similarly controlled.

FIG. 3 is a characteristic diagram of the displacement of the valve shaft and the flow rate M on the melt side and the flow rate N on the water side. In the range of P, both the first valve body 22 and the second valve body 24 are closed. ing. When the hot water side is closed by the above valve closing operation, the motor 12 is stopped at point Q, and when the water side is closed, the motor 12 is stopped at point R. It is sufficient that the Q point and the R point are within the P range, and therefore the P range may be set to be larger than the overshoot amount of the valve shaft 6.

At the time of manufacture, the valve shaft is in a position where either the first valve body 22 or the second valve body 24 is open, for example, S.
If it is assembled at points, the valve shaft 6 will automatically move to the P range and stop if the above valve closing operation is first performed, and the adjustment step is unnecessary.

As described above, the flow rate stop detection unit 30 and the valve closing time motor control unit 31 for controlling the motor 12 at the time of valve closing in response to the signal of the flow rate stop detection unit 30 are provided, and the flow rate sensor 13 is provided.
By detecting the stop of the signal of No. 3, the valve closing position is surely detected and the motor 12 is stopped, and the adjustment step at the time of manufacturing can be omitted and the position detector can be omitted, so that the cost of the device can be reduced. It is possible.

Further, the flow rate calculating section 14 for measuring the pulse period of the flow rate sensor 13 and calculating the flow rate signal, and the flow rate stop detecting section 30 for detecting that the pulse signal of the flow rate sensor 13 has not been generated for a certain period of time. With the above configuration, the stop of the flow rate can be detected in the shortest time after the pulse signal of the flow rate sensor 13 is stopped, and the closed position of the valve can be accurately detected.

[0019]

As described above, according to the flow rate control device of the present invention, the valve body, the valve shaft, and the motor for driving the valve shaft,
It is composed of a flow rate sensor and a valve closing motor control unit that detects the stop of the signal of the flow rate sensor and controls the motor when closing the valve,
By detecting the stop of the flow sensor signal when the valve is closed, the valve closing position can be reliably detected and the motor stopped, so the adjustment process during manufacturing can be omitted and the position detector can be omitted. Can be made smaller.

Further, since the flow rate stop detector for detecting that the signal of the flow rate sensor has not been generated for a certain period of time is constituted, it becomes possible to detect the stop of the flow rate after the signal of the flow rate sensor is stopped, and the valve is stopped. The position can be detected accurately.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a flow rate control device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of motor speed and flow rate when the device is opened.

FIG. 3 is a characteristic diagram of flow rate with respect to valve shaft displacement of the device.

FIG. 4 is a block diagram of a conventional flow control device.

FIG. 5 is a characteristic diagram of a motor speed with respect to a flow rate error of a conventional flow rate control device.

FIG. 6 is a characteristic diagram of flow rate with respect to valve shaft displacement.

[Explanation of symbols]

 6 Valve Shaft 12 Motor 13 Flow Rate Sensor 18 First Inlet 19 Second Inlet 20 Outlet 21 First Valve Seat 22 First Valve Body 23 Second Valve Seat 24 Second Valve Body 30 Flow Stop Detector 31 Motor control unit when valve is closed

Claims (2)

[Claims] 1. A flow passage body having an inlet and an outlet, a valve seat and a valve body provided in the flow passage body for opening and closing the flow passage and adjusting a flow rate, and a valve shaft connected to the valve body. A motor that drives the valve shaft to open and close the valve, a flow sensor provided on the outlet side of the flow path main body, and a closed valve that detects the stop of the signal of the flow sensor when the valve is closed to stop the motor. A flow control device having a motor control unit. 2. A flow rate calculating section for measuring a pulse cycle time of a flow rate sensor for generating a pulse signal having a frequency proportional to the flow rate, and calculating a flow rate signal from the time, and a pulse signal for the flow rate sensor being generated for a fixed time. The flow rate control device according to claim 1, wherein the flow rate control device includes a flow rate stop detection unit that detects that the flow rate control is not performed.