JPH0210051A - Water quantity control device for hot water feeder - Google Patents

Abstract

PURPOSE:To stop a water flow passage area varying device in a position where an overload exerted on a motor is minimized to protect a motor by a method wherein a signal from a motor to drive the water flow passage area varying device is detected, and it is judged whether or not there is possibility for an overload to be exerted on the motor. CONSTITUTION:Water is fed through an inlet 1, and is fed through an outlet 4 after flowing through a water quantity sensor 2 serving as a water quantity detecting device and a water quantity proportioning valve 17 serving as a water flow passage area varying device. The water quantity proportioning valve 17 is controlled by a control device 16 through a motor 5 and a motor running part 6. When water flows to a water flow passage, a signal from the water quantity detecting device 2 is fed to the control device 16, and it is judged whether or not a target water quantity flows. When a water quantity is different, the motor 5 is run. When an overload is exerted on the motor running the water flow passage area varying device, a water quantity control sequence is suspended, and the water flow passage area varying device is stopped in a position where a load exerted on the motor is minimized to protect the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a water flow rate control device for a water heater that obtains hot water by utilizing heat generated by combustion.

BACKGROUND ART As an example of a conventional technique, a method of controlling the amount of water by changing the area of a water passage using a valve will be described.

2 H/ In FIG. 7, water is supplied from a water inlet 1, passes through a water amount sensor 2 as a water amount detection device, a water amount proportional valve 3 as a water passage area variable device, and is supplied from an outlet 4. The water volume proportional valve 3 is controlled by a control device 7 via a motor 5 and a motor drive section 6.

FIG. 8 shows a schematic diagram of the water proportional valve 3 and the motor 5. The torque of the motor 5 is transmitted to the gear B11 by the gear A10, and the shaft of the valve 13 rotates. A portion of the shaft is a threaded portion, and the valve 13 moves up and down in proportion to the rotation of the shaft. Water is at entrance 8
Since the water flows from the water to the outlet 9, the vertical movement of the valve 13 changes the water passage area and the amount of water can be changed.

FIG. 9 shows an outline of the water flow control sequence when the target water flow is set. When water flows into the water passage, the water amount detection device 2
A signal S2 is sent to the control device 7, and it is determined whether or not the target water volume is flowing (S3). If the water volume is different, the motor 5 is driven and the water volume is detected until the target water volume is reached (S5).
) and motor drive (S4) are repeated. Then, when the target water amount is reached, the motor 5 is stopped (S7).

3. Problems to be Solved by the Invention When considering water flow control when a large amount of water is flowing, a large water pressure is applied to the valve 13 in the direction of widening the water passage. At this time, if an attempt is made to move the valve 13 in a direction to narrow the water passage, work against the water pressure is required. Therefore valve 1
There is a possibility that the motor 5 that drives the motor 3 may be overloaded.
If it takes a long time to reach the target water volume, there is a risk of damage to the motor due to overload.

In order to solve the above problems, the present invention detects a signal from a motor that drives a water passage area variable device, determines whether or not there is a possibility of overloading the motor, and determines whether or not there is a possibility of overloading the motor. In this case, the purpose is to protect the motor by stopping the variable water passage area device at a position where the load on the motor is minimum.

Means for Solving the Problems In order to achieve the above object, a water flow rate control device for a water heater according to the present invention includes: a water flow rate detection device for detecting the amount of water flowing through a water passage; a water passage area variable device; a drive device that drives the area variable device; a control device that controls the drive device based on a signal from the water amount detection device; and a passage area variable device drive that controls the operation of the path area variable device based on the signal from the drive device. It is a configuration equipped with means.

According to the configuration described in "-, the present invention detects a signal from a motor that drives a water passage area variable device, determines whether or not there is a possibility of overloading the motor, and determines whether or not there is a possibility of overloading the motor. If there is, interrupt the water flow control sequence and change the water passage area,
The variable water passage area variable device is driven and the water passage area variable device is stopped at a position where the load applied to the motor is minimum, thereby protecting the motor.

Example FIG. 1 is a block diagram showing an embodiment of the present invention.

Water is supplied from a water inlet 1, a water amount sensor 2 as a water amount detection device, and a water amount proportional valve 17 as a water passage area variable device.
through the outlet 4. The water volume proportional valve 17 is controlled by a control device 16 via a motor 5 and a motor drive unit 6. In addition, the control bag 5 . Has a timer function.

FIG. 2 shows a configuration diagram of the water proportional valve 17, the motor 5, and the microswitch 15. Water is supplied from the water inlet 18 and passes through the cylinder 21, then the disk A22 and the disk B.
23 and is supplied from the outlet 19. The micro switch 15 is turned on and off by the cam 24 attached to the motor 5.
It is configured to turn on at the position where the water passage area of the disk is maximum. Also disk A
22 is rotated by the motor 5 via the cylinder 21;
Disc 823 is fixed to the water passage.

As shown in FIG. 3, water passages are formed in each of the disks A22 and 823, and as the disk A22 rotates on the surface of the disk 823, the area of the water passages changes.

FIG. 4 shows the change in the load current applied to the motor 5 when the water amount is changed by rotating the disk A22 in the water amount proportional valve 17. In FIG. 4, when the disk A22 is rotated in a direction that decreases the amount of water, the load current 1 tends to increase, and the slope of the load current 1 increases as the water pressure increases. In addition, l m a x is the limit current value at which the motor will be damaged if a load current of more than this flows, and 1 o
is a threshold current value at which the control device determines that there is a possibility that the motor may be damaged if the load current 1 (1o≦1) continues to flow for 10 seconds.

FIG. 5 shows a schematic diagram of the water flow rate control sequence when the target water volume is set in the present invention. When water flows into the water passage,
A signal from the water amount detection device 2 is sent to the control device 16 to determine whether or not the target water amount is flowing (S10), and if the water amount is different, the motor 5 is driven. At this time, the load current I flowing through the motor 5 is detected, and if 1o>1, water volume detection (s13) and motor drive (s13) are performed until the target water volume is reached.
Repeat Si1). If 10≦1, the controller internal timer is activated 7 (S16). This timer is configured to turn off after to seconds, and if the target water amount is reached (51B) or l o) I (520) before the timer is turned off, the timer is canceled and normal water amount control is resumed. If the timer is not released within to seconds, the motor is driven in the direction in which the amount of water increases (522), and the motor is stopped when the microswitch 15 is turned on.

(s24) FIG. 6 shows a configuration diagram of the water amount control device 16. The signal from the water amount detection device 2 is sent to the 110 section 26 of the microcomputer 25 via the transistor 24. Further, the load current of the motor 5 is converted by a resistor into a voltage proportional to the current value, which is converted into a 4-bit signal by the A/D converter 33 and sent to the rlo section 26. Further, the ON signal of the microswitch 15 is sent to the 110 section 26 via the transistor 34. On the output side of the 110 section 26, there is a D/A converter 32 as a motor drive section.

The water amount detection device 2 outputs a pulse signal according to the amount of water. 1 corresponding to the target water volume is stored in the ROM section 29 in advance.
The number of pulses per second is stored, and the CPU 27 compares the number of pulses from the water amount detection device 2 with the target number of pulses. At this time, if the actual number of pulses differs from the target number of pulses, the water volume proportional valve 17 is operated.
/A converter 32. While the water volume proportional valve 17 is in operation, the signal from the A/D converter 33 continues to be input from the 110 section 26. Then, the signal value of the A/D converter 33 becomes the threshold current value 1.
If the CPU 27 determines that o has been exceeded, the timer 30
Start. At this time, the RAM section 28 stores the most recently sampled signal Pa from the A/D converter 33 and the most recently sampled signal P1. t.

If the timer 30 does not reach I(lo) in seconds and the timer 30 is turned off, the output to the D/A converter 32 is set to O and the water flow control sequence is stopped.Next, compare PO and Pl stored in the RAM 2B. If PO>Pl, the disk A22 was rotating in the direction in which the load current was increasing just before the sequence was stopped, so a signal is sent to the D/A9...converter 32 in the direction to reverse the motor 5. Conversely, if it is PO (Pi), a signal is sent to the D/A converter 32 so that the motor 5 rotates in the same direction as it was just before the sequence was stopped.

The signal sent to the D/A converter 32 is the microswitch 1
When the signal from 5 is input to the 10 part 26, it becomes O.

At this point, the water volume proportional valve 17 has stopped at the position where the motor load current is minimum, that is, at the position where the water volume is maximum.

With the configuration of the above embodiment, if the motor that drives the variable water passage area device is overloaded, the water flow control sequence is stopped, the variable water passage area device is stopped at the position where the load on the motor is minimum, and the motor It protects the

Effects of the Invention As is clear from the above embodiments, the water flow rate control device for a water heater of the present invention includes a water flow rate detection device that detects the amount of water flowing through a water passage, a water passage area variable device, and a water passage area variable device. a drive device that drives the device; a control device that controls the drive device based on a signal from the water amount detection device; and a passageway that controls the operation of the passage area variable device based on a signal 10 from the drive device. Due to the configuration equipped with a variable area device driving means, if there is a possibility that the motor, which is the driving device, may be overloaded, the variable water passage area device is stopped at a position where the load on the motor is minimal to protect the motor. It is something.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a water flow control device for a water heater showing an embodiment of the present invention, Fig. 2 is a sectional view of the main parts of the water flow proportional valve, motor, and microswitch, and Fig. 3 is a schematic diagram of the disc valve. A perspective view, FIG. 4 is a diagram showing the relationship between the amount of water and the load current flowing to the motor, FIG. 5 is a schematic sequence diagram of an embodiment of the present invention, and FIG. 6 is a diagram showing the amount of water in an embodiment of the present invention. A detailed view of the control device, FIG. 7 is a configuration diagram of a water flow control device for a conventional water heater, FIG. 8 is a sectional view of a conventional water flow proportional valve, and FIG. 9 is a schematic diagram of a conventional water flow control sequence. 2...Water amount detection device, 5...Motor, 7
．． 16.25... Control device, 15...
Micro switch, 22.23...Disc valve, 3
2...D/A converter, 33...A/D converter.

Claims (1)

[Claims] A water amount detection device that detects the amount of water flowing through the water passage, a water passage area variable device, a drive device that drives the passage area variable device, and a signal from the water amount detection device,
A water flow control device for a water heater, comprising: a control device that controls the drive device; and a passage area variable device drive means that controls the operation of the passage area variable device based on a signal from the drive device.