JPH0572603B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention involves mixing hot water at a predetermined temperature with water via an interlocking valve, controlling the mixing ratio using a control means, and adjusting the temperature to a desired set temperature. The present invention relates to a hot water mixing valve device capable of supplying hot water to a boiler, and particularly relates to an improvement in the control means.

(Prior art) A hot water supply valve that controls the amount of hot water passing through at a predetermined temperature, and a water supply valve that operates in conjunction with the hot water supply valve to control the amount of water that passes through, is provided, and the hot water and water passing through each valve are mixed in a mixing water pipe. Various devices are known that supply hot water at a predetermined temperature determined by a setting means to the boiler by controlling this mixing ratio.
In this case, due to pressure fluctuations from the hot water supply pipe or water supply pipe, the difference between the set temperature and the temperature of the hot water supplied to the cooker (hereinafter referred to as "actual temperature") fluctuates greatly, causing overshoot or undershoot. There is a risk. In this case, the aforementioned valve opening/closing speed is usually increased in order to speed up the return to the set temperature.

A conventional valve opening/closing speed control unit for controlling this type of control is shown in FIG. 7, for example. That is, the unit includes a hot water temperature detecting means 71 for detecting the actual temperature T _A in the mixing water pipe, a hot water temperature setting means 72 for setting a desired hot water temperature, and an actual temperature T _A detected by the hot water temperature detecting means 71. Comparison means 73 that calculates the difference ΔT from the set temperature T _O of the hot water temperature setting means 72, and memory control means 74 that generates an address for reading from the memory (ROM) 75 in accordance with the output ΔT of the comparison means 73. , and the aforementioned
Equipped with ROM75 etc.

The ROM 75 stores a characteristic curve 80 relating to the opening/closing operation speed R of the valve, which is determined according to the temperature difference ΔT between the actual temperature T _A and the set temperature T _O , as shown in FIG. 8, for example. That is, the control means, depending on the temperature difference ΔT between the actual temperature T _A and the set temperature T _O ,
The valve opening/closing speed R is sequentially read out from the memory 75 and controlled as shown in the characteristic curve 80 in FIG.
In this case, when the temperature difference ΔT is larger than a certain value a, the valve operating speed R responds at the upper limit speed R _M ,
When the temperature difference ΔT becomes smaller than this value a, the valve operating speed R also gradually becomes smaller.

(Problem to be Solved by the Invention) According to the control means having the characteristic curve ₈₀ as shown in FIG. The response will be slow, and if the upper limit speed R _M is set high enough, the response will be quick when the temperature difference is less than a, but due to pressure fluctuations, it will cause an overshoot that greatly exceeds the set temperature or an undershoot that falls below the set temperature. As a result, hunting, which repeats these fluctuations, becomes more likely to occur. In order to prevent this hunting, it has been proposed that a hunting detecting means 76 is provided in the configuration shown in FIG. 7, and second type characteristic curves 90 and 91 as shown in FIG. 9 are stored in the ROM 75. This changes the characteristic curve of the ROM 75 from curve 90 to curve 9 so as to reduce the rate of change in valve operating speed when hunting occurs.
1. However, this control is a response after hunting occurs, and does not minimize overshoot and undershoot or prevent hunting.

Therefore, the present invention has been made in an attempt to eliminate the above decisions of the prior art, and provides a hot water mixing valve device that can minimize overshoot and undershoot during pressure fluctuations, or prevent hunting. The purpose is to

(Means and effects for solving the problem) In order to achieve this object, according to the present invention, at least two types of characteristic curves of the control means are provided, and when the temperature difference exceeds a specific switching temperature, one type of characteristic curve is provided. Control is performed so that the characteristic curve shifts from one characteristic curve to the other, but multiple switching temperatures are provided for this transition, and the temperature difference is specified as positive and negative reference temperatures, and when the temperature difference exceeds the positive reference temperature. Sometimes, the switching temperature on the negative side is changed, and when the negative reference temperature is exceeded, the switching temperature on the positive side is changed, and the switching temperature is changed each time this process is repeated. By adopting such a configuration, it is possible to make it difficult to sequentially shift to the rapid characteristic every time the transition is performed,
It becomes possible to suppress overshoot and undershoot caused by pressure fluctuations.

For example, according to the hot water mixing valve device according to the embodiment of the present invention, the hot water supply valve 3 that controls the amount of passing hot water at a predetermined temperature and the water supply valve 4 that controls the amount of water passing through are driven by one axis, or each A driving means that is driven by two shafts in conjunction with each other, a mixing water pipe 5 that mixes a predetermined amount of hot water passing through the hot water supply valve 3 and a predetermined amount of water that passes through the water supply valve 4 and guides the mixture to the drain 6; Temperature detection means 8 and flow rate detection means 7 that respectively detect the temperature and flow rate of hot water in the mixing water pipe 5
and valve opening/closing to determine the opening/closing speed of the hot water supply valve 3 and the water supply valve 4 according to a certain characteristic curve based on the temperature _{difference ΔT between the actual temperature T A of} the temperature detection means 8 and the desired set temperature T O. and a control means having a speed control unit, the valve opening/closing speed control unit of the control means having at least two characteristic curves, one of which determines the opening/closing speed of the hot water supply valve 3 and the water supply valve 4. Set multiple switching temperatures (a1, a2, a3, -a1, -a2, -a3) that transition from B to the other characteristic curve A,
The temperature difference ΔT is the switching temperature (a1, a2, a3, −
a1, -a2, -a3), and the temperature difference ΔT specifies positive and negative reference temperatures (b, -b), and if the temperature difference ΔT exceeds the positive reference temperature (b). Sometimes the negative side switching temperature is changed, and when the negative reference temperature (-b) is exceeded, the positive side switching temperature is changed.
Each time this process is repeated, the switching temperature is controlled to be changed sequentially.

Further, for example, according to the hot water mixing valve device according to the embodiment of the present invention, the valve opening/closing speed control unit of the control means lowers the switching temperature on the negative side when the temperature difference exceeds the positive reference temperature; When the negative reference temperature is exceeded, the positive switching temperature is controlled to be high.

(Embodiments of the invention) Examples of the invention will be described below with reference to the accompanying drawings. Note that the same reference numerals in each figure indicate similar objects.

FIG. 1 shows an overall configuration diagram of a hot water mixing valve device according to an embodiment of the present invention. In the figure, 1 is a water supply pipe for supplying hot water at a predetermined temperature, 2 is a water supply pipe for supplying water, 3 is a hot water supply valve that controls the amount of hot water supplied by the hot water supply pipe 1, and 4 is this water supply pipe. A water supply valve 5 is interlocked with the hot water supply valve 3 and controls the amount of water that passes through the water supply pipe 2; A mixing water pipe that guides the water to the water pipe 6, a water pipe 6 that supplies hot water at a desired temperature, a flow sensor (flow rate detection means) 7 that measures the flow rate of the mixed water flowing through the mixing water pipe 5, and a water flow sensor 8 that measures the flow rate of the mixed water flowing through the mixing water pipe 5. A temperature sensor (temperature detection means) such as a thermostat that measures the temperature, 9 an operation setting means for turning on and off the device, and setting the temperature and amount of hot water desired to be supplied; 10 an operation setting means 9 Arithmetic control means for forming an opening/closing operation command signal CC for opening and closing the two valves 3 and 4 based on the settings of the arithmetic and control means 10; 11 is a drive circuit and drive circuit for driving the valves 3 and 4 by the command signal CC of the arithmetic and control means 10; It is a driving means including a motor.

That is, according to this embodiment, the flow rate sensor 7
Based on the detection signal of the temperature sensor 8, the arithmetic control means 10 forms a command signal CC so that hot water of a set amount and temperature is obtained in the run 6,
The valves 3, 4 are actuated via the drive means 11. Therefore, the arithmetic control means 10 has a flow rate control unit and a valve opening/closing speed control unit that controls the opening/closing speed of the valve in order to control the hot water temperature. The present invention relates to the latter, and a valve opening/closing speed control unit according to an embodiment of the present invention is shown in FIG. In the figure, 21 is a hot water temperature detection means that includes the aforementioned temperature sensor 8 and forms an electric signal corresponding to the actual temperature T _A , and 22 is an electric signal T that corresponds to the desired hot water temperature among the aforementioned operation setting means 9. 23 is each output signal of _the hot water temperature detecting means 21 and the hot water temperature setting means 22.
Comparison means 24 calculates the difference between T _A and T _O and forms an electric signal corresponding to the temperature difference ΔT between the actual temperature T _A and the set temperature T _O ; 24 indicates whether the temperature difference ΔT is larger than a certain switching temperature a; 25 is a switching temperature setting means for setting and changing the switching temperature a of the switching command means 24; 26 is a switching temperature setting means for determining whether the temperature difference ΔT is Within the reference temperature range for a certain period of time (e.g. 10 seconds)
temperature difference monitoring means to determine whether the
27 is a memory (ROM) based on the signals ΔT and SW
Memory control means determines the content to be read from 28 and generates a predetermined address. 28 stores a rapid speed characteristic curve A and a slow speed characteristic curve B shown in FIG. 3 in order to drive the valves 3 and 4. It's memory.

Among the above components, important ones will be explained in further detail. The switching command means 24 passes the temperature difference signal ΔT as it is, but also monitors whether the temperature difference ΔT exceeds the switching temperature set value a,
If ΔT>a, a switching signal SW is sent out. Before the switching signal SW is generated, data corresponding to the slow speed characteristic curve B with a small rate of change in FIG. 3 is read from the ROM 28, and corresponding control is executed. Further, after the switching signal SW is generated, switching is made to the rapidity characteristic curve A having a large rate of change shown in FIG. 3, the corresponding data is read from the ROM 28, and the corresponding control is executed. When ΔT≦a, control is performed using slow speed characteristic curve B.

By the way, such a switching temperature setting value a is given by the switching temperature setting changing means 25, and this switching temperature setting changing means 25 can change, for example, three switching temperature settings, first, second, and third. Value (a1,
Prepare a2, a3) (a1<a2<a3) on the positive side and negative side. These set values (a1, a2, a3) are changed from set value a to a1 on the positive side every time the switching signal SW of the switching command means 24 is sent out, that is, every time the reference temperature on the positive side and the negative side is exceeded. →a2→a3 and negative side is −a1
Change →−a2→−a3.

Further, the temperature difference monitoring means 26 includes a timer that is activated upon generation of the switching signal SW, and the comparison means 23 is provided for a certain period of time (for example, 10 seconds) from the time when the timer is activated.
If the output temperature difference ΔT is maintained within the reference temperature range, the switching temperature setting changing means 25 is reset by generating a reset signal RS.
Return the output setting value to the initial value, that is, (a1, −a1).

Therefore, the memory control means 27 normally controls the slow speed characteristic curve B to be read from the memory 28, but the temperature difference ΔT between the actual temperature T _A and the set temperature T _O is the first switching temperature a1. , so that the switching temperature changes to the rapidity characteristic curve A at this switching temperature a1.
Change address. Further, since the switching temperature set value a is subsequently changed to the second set value a2 as described above, the memory control means 27 receives this set value a2 as data so that it can generate a predetermined address. It's getting old. As is clear from the above explanation, according to the present invention, the transition from the slow speed characteristic curve B to the rapid speed characteristic curve A starts from the switching temperature (a1, -a1), and the positive side and negative side standards are set. The temperature is changed sequentially each time the temperature is exceeded, and it is not possible to change the temperature at multiple locations at the same time.
In addition, in the range of -0.5≦∆T≦+0.5, the actual temperature is acceptable assuming that T _A is at the set temperature T _O.
This is a so-called dead area where the valve is not activated.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. 4 and the actual temperature change characteristic diagram of FIG. 5. In the following description, the numbers 40 to 49 correspond to the symbols of each block in the flowchart. Further, symbols such as 43-Y and 43-N represent that the judgment of the judgment block 43 is positive and negative, respectively. Furthermore, the switching temperature (a1, a2,
a3) are taken at 2.5°C intervals of 3°C, 5.5°C, and 8°C, respectively, and the reference temperature b is the first switching temperature in this example.
Suppose it is kept at 3℃, the same as a1.

When the device starts normally, 40, the setting a of the switching temperature setting change means 25 is changed to the first switching temperature (a1) (=
3°C), the main controller such as a CPU (not shown) adjusts the coefficients m and n of the switching temperature setting change means 25.
41 and 42, each with 1.

Here, if the actual temperature T _A begins to rise due to pressure fluctuations and the difference ΔT from the set temperature T _O exceeds a1 = 3°C, the switching command means 24 checks that T _A > T _O + a1. Therefore, 43, this judgment is established, and the 43-Y switching command means 24 sends out the switching signal SW, and operates the memory control means 27 so that the memory 28 selects the rapidity characteristic curve A. At the same time, in order to exceed the reference temperature b=3°C, this switching signal SW is given to the switching temperature setting change means 25, and the coefficient value is advanced by one to set n=2 44, and the switching temperature setting value -a2 is prepared. . This slows down the control to the undershoot side and suppresses the occurrence of undershoot.

However, if undershoot occurs, the switching command means 24 has checked T _A <T _O -a2, so this judgment is established and the switching command means 24
sends out the switching signal SW and operates the memory control means 27 so that the memory 28 selects the rapidity characteristic curve A. Also, by this, the reference temperature b=
Since it exceeds -3℃, T _A ≦T _O -b holds and 45-
Y, this switching signal is sent to the switching temperature setting changing means 25.
Given SW, advance one coefficient value and set m = 2 and 4
6. Prepare the switching temperature set value a2. As a result, the control toward the overshoot side is slowed down to suppress the occurrence of overshoot. According to this example, a similar modification is made at the switching temperature (a3) (m
=3, n=3).

By the way, when overshoot or undershoot is controlled and the normal state is restored, the temperature difference ΔT falls within a certain range. This check is performed by the temperature difference monitoring means 26. That is, the temperature difference monitoring means 26 monitors T _O −b≦T _A ≦T _O +b, and
7. If this judgment is established, 47-Y, set its own timer and continue 48 monitoring 49;
As a result, if T _O -b≦T _A ≦T _O +b is maintained until the end of the timer setting time (for example, 10 seconds), then 4
9. Return the coefficient values of the switching temperature setting change means 25 to the initial values m=1, n=1, and change the switching temperature to the first temperature.
Let it be a1. In this way, by returning the switching temperature to the initial state after suppressing overshoot and undershoot due to pressure fluctuations, overshoot and undershoot during an initial cold start can be suppressed.

Note that the symbols A and B below the time axis t in FIG.
indicates the different characteristic curves A and B for executing the control. Further, "0" in the figure indicates the time point at which the timer is activated.

The present invention is not limited to the above embodiments and modifications, but within the technical scope of the present invention,
Various other embodiments and variations are possible;
Also, the fact that equivalent components can be exchanged means that
It will be clear to those skilled in the art. For example, it goes without saying that the number of switching temperatures to be set is not limited to three, but may be greater. Further, the starting time point of the timer for returning to the initial state can be determined as appropriate, not only the time point when the actual temperature enters the allowable temperature range. Furthermore, the characteristic curves are not limited to the two characteristic curves A and B with different slopes, but as shown in FIG.
Characteristic curves C and D that are parallel to each other may also be used.

(Effects of the Invention) According to the present invention, as described above, the valve speed control unit of the control means is provided with at least two types of characteristic curves of slow speed and rapid speed, and the switching for transition from slow speed to rapid speed is provided. By setting multiple temperatures and changing this switching temperature each time the positive and negative reference temperatures are exceeded, pressure fluctuations during normal hot water supply and overshoot and undershoot caused by initial cold start can be minimized, and hunting can be minimized. Thus, it is possible to obtain a hot water mixing valve device that can prevent this from occurring.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram of an embodiment of the present invention, FIG. 2 is a main system diagram of an embodiment of the invention, FIG. Flowchart for explaining the operation of the embodiment, fifth
The figure is a characteristic diagram for explaining the operation of the embodiment of the present invention, FIG. 6 is a diagram showing the memory configuration of another embodiment of the present invention, and FIGS. 7 to 9 are explanatory diagrams of the conventional device. Ru. In the drawing, 3 is a hot water supply valve, 4 is a water supply valve, 5 is a mixing water pipe, 6 is a counter, 7 is a flow rate detection means (flow rate sensor), 8 is a temperature detection means (temperature sensor), 9 is an operation setting means, and 10 is a calculation It is a control means.

Claims (1)

[Scope of Claims] 1. A driving means that drives a hot water supply valve that controls the amount of hot water at a predetermined temperature passing through and a water supply valve that controls the amount of water that passes through one shaft or two shafts in conjunction with each other. , a mixing water pipe that mixes a predetermined amount of hot water passing through the hot water supply valve and a predetermined amount of water that passes through the water supply valve and guides the mixture to the water tank; a temperature detection means that detects the temperature of the hot water in the mixing water pipe; and control means having a valve opening/closing speed control unit that determines the opening/closing speed of the hot water supply valve and the water supply valve according to a certain characteristic curve based on the temperature difference between the temperature detected by the temperature detection means and a desired set temperature. In the hot water mixing valve device, the valve opening/closing speed control unit of the control means has at least two characteristic curves, and a transition from one characteristic curve to the other characteristic curve that determines the opening/closing speed of the hot water supply valve and the water supply valve. a plurality of switching temperatures to be set, the transition is performed when the temperature difference exceeds the switching temperature, and the temperature difference specifies positive and negative reference temperatures, and when the temperature difference exceeds the positive reference temperature, the transition is performed; The hot water mixture is characterized in that the switching temperature on the side is changed, and when the negative reference temperature is exceeded, the switching temperature on the positive side is changed, and the switching temperature is sequentially changed each time this process is repeated. Valve device. 2. The valve opening/closing speed control unit of the control means lowers the switching temperature on the negative side when the temperature difference exceeds the positive reference temperature, and increases the switching temperature on the positive side when the temperature difference exceeds the negative reference temperature. The hot water mixing valve device according to claim 1, wherein the hot water mixing valve device is configured to control the hot water mixing valve device.