JP2003254534A - Gas flow rate control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of unchangable heating power of a gas burner even if opening is changed to opening or more of a gas valve coincident in secondary pressure and target secondary pressure when the secondary pressure reduces when the opening of the gas valve is maximum when primary pressure changes and reduces in a gas passage in a conventional gas flow rate control device. <P>SOLUTION: The gas passage 21 continues with a gas injection nozzle, and is provided with a flow rate adjusting means 2 for adjusting a gas flow rate of fuel gas to the gas injection nozzle, and a pressure sensor 6 for detecting the secondary pressure of the fuel gas on the downstream side of the flow rate adjusting means. The flow rate adjusting means has orifice parts 4 and 5 for increasing-decreasing the secondary pressure corresponding to the gas flow rate up to a maximum gas flow rate from a minimum gas flow rate by changing the opening of the gas passage. The secondary pressure is detected by making the fuel gas flow to the gas passage via the flow rate adjusting means, and opening of the orifice parts is corrected according to the detected secondary pressure. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas flow rate control device used for gas appliances such as gas stoves.

[0002]

2. Description of the Related Art A gas flow rate control device of this type is, for example,
Japanese Unexamined Patent Publication No. 2001-56118 is known and is used, for example, to reduce the change in the set heating power of the gas burner when adjusting the heating power of the gas burner provided in the gas stove.

In this case, the gas flow rate control device is a motor which is a flow rate adjusting means in which a gas passage connected to a gas injection nozzle connected to a mixing pipe of a gas burner is provided with a throttle portion for changing the opening of the gas passage. It has a drive type gas valve and a pressure sensor which is a secondary pressure detecting means for detecting a secondary pressure in a gas passage provided between the gas valve and the gas injection nozzle.

Then, by the microcomputer controlling the operation of the gas stove, the motor is controlled so that the secondary pressure detected by the pressure sensor matches the target secondary pressure stored in the microcomputer in advance, and the opening degree of the throttle portion is adjusted. Adjust to reduce the change in set firepower.

[0005]

However, in the above, when the primary pressure in the gas passage fluctuates and becomes low, the secondary pressure at the maximum opening of the gas valve becomes low. The thermal power of the gas burner cannot be changed even if the opening is changed beyond the opening of the gas valve at which the secondary pressure and the target secondary pressure match. For this reason, there has been a problem that the heating power widths between the set heating powers become non-uniform, and the usability of the gas appliance deteriorates.

Further, in the above-mentioned one, the CPU of the microcomputer calculates the control position of the motor from the detection result of the pressure sensor every time the motor is controlled to adjust the heating power,
Since the motor drive control processing for adjusting the opening of the gas valve is performed at the same time, the load on the CPU increases. For this reason, in particular, in the gas stove that electronically controls the operation of the utensil in order to improve the convenience of the cook, the CPU having a high calculation processing capability is used.
However, there is a problem that the cost is increased.

In view of the above problems, therefore, the present invention does not require a CPU having a high calculation processing capacity, and moreover, even if the primary pressure changes, the heating power widths between the set heating powers of the gas burner can be made uniform. An object is to provide a gas flow rate control device.

[0008]

In order to solve the above-mentioned problems, a gas flow rate control device of the present invention adjusts a gas flow rate of a fuel gas to a gas injection nozzle in a gas passage communicating with the gas injection nozzle. Means and a secondary pressure detecting means for detecting the secondary pressure of the fuel gas on the downstream side of the flow rate adjusting means are provided, and the flow rate adjusting means changes the opening degree of the gas passage to set the heating power of the gas burner. In a gas flow rate control device having a throttle part for increasing or decreasing the secondary pressure corresponding to the gas flow rate from the minimum gas flow rate to the maximum gas flow rate, the fuel gas is caused to flow through the gas passage via the flow rate adjusting means, The secondary pressure is detected by the pressure detection means, the opening of the throttle portion corresponding to the gas flow rate that determines each set thermal power is corrected from the detected secondary pressure, and the thermal power of the gas burner is adjusted by the corrected opening of the throttle portion. To make adjustments And butterflies.

According to the present invention, when the fuel gas is flown through the gas passage, the fuel gas whose flow rate is adjusted by the flow rate adjusting means flows through the gas injection nozzle. In this case, the secondary pressure detection means
Detecting the secondary pressure of the fuel gas in the gas passage between the flow rate adjusting means and the gas injection nozzle, from the detected secondary pressure,
Correct the opening of the throttle that corresponds to the gas flow rate that determines each set thermal power of the gas burner. Then, the heating power of each gas burner is adjusted according to the opening degree of the throttle portion after correction.

In this case, the detection of the secondary pressure is performed by, for example,
It is advisable to change the opening of the throttle to perform the minimum gas flow rate and the maximum gas flow rate.

Further, in the case of detecting and correcting the secondary pressure at the maximum opening of the throttle portion, if the correction is made on the basis of the secondary pressure increased due to the fluctuation and increase of the primary pressure, it is more than necessary. It is conceivable that the gas burner fire power will increase.

In this case, the detection of the secondary pressure is performed for the maximum gas flow rate by changing the opening of the throttle portion, and when the detected secondary pressure becomes higher than the initial secondary pressure, the throttle is changed from the initial secondary pressure. The opening of the part may be corrected.

Further, when the opening of the throttle portion is corrected based on the secondary pressure detected by the secondary pressure detecting means, the characteristic of the secondary pressure detecting means changes with time, for example, the secondary pressure becomes higher than usual. If the display is high, as in the case described above, the inconvenience of increasing the heating power of the gas burner more than necessary occurs.

In this case, if the detected secondary pressure is out of the predetermined pressure range, a warning of the failure of the secondary pressure detecting means may be given.

It is preferable that the flow rate adjusting means has a closing function.

In this case, an opening / closing valve is provided between the secondary pressure detecting means and the gas injection nozzle, and when the supply of the fuel gas to the gas injection nozzle is stopped, the opening / closing valve is closed before the flow rate adjusting means. However, if the pressure reduction rate is detected by the detection means, it is possible to determine the occurrence of gas leakage from the secondary pressure detection means or the like.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIGS.
It is a gas flow rate control device of the present invention. Gas flow controller 1
Has an apparatus main body 12 having a gas passage 11 connected to a gas injection nozzle (not shown) connected to a mixing pipe of a gas burner provided in a gas stove, for example. Device body 12
A gas valve 2 which is a flow rate adjusting means for adjusting the gas flow rate of the fuel gas to the gas injection nozzle is provided on the lower surface of one end of the.

The gas valve 2 has a valve casing 22 having an internal passage 21, a gas inlet 23 is opened on the side surface of the valve casing 22, and the gas inlet 23 is
It communicates with the gas outlet 24 on the upper surface of the valve casing 22 which communicates with the gas passage 11 through the internal passage 21.

A motor 3 such as a stepping motor or a geared motor having each rotation detecting means 31 is connected to the lower surface of the valve casing 22, and one end of a rotary shaft 32 of the motor 3 projects into the internal passage 21 via a sealing material 33. ing.

In the internal passage 21, a rotary disc 4 located upstream of the gas outlet 23 and connected to one end of a rotary shaft 32, and fitted to the valve casing 22 above the rotary disc 4. Fixed disk 5 is provided. The rotating disk 4 and the fixed disk 5 are the internal passage 2
A throttle unit that changes the opening of the passage area 1 is configured.

As shown in FIG. 2, the fixed disk 5 includes:
Five holes 51, 52, 53, 54, 5 which are first communication holes
5 are continuously provided on the same circumference with different opening areas. On the other hand, in the rotary disc 4, when the rotary shaft 32 rotates by a predetermined angle, the holes 51, 5 of the first communication holes are formed.
Allowing communication between the gas inlet 23 and the gas outlet 24 via the internal passage 21 in conformity with 2, 53, 54, 55 1
An elliptical second communication hole 41 is provided.

The minimum gas flow rate at which the flame of the gas burner is not extinguished depends on the type of fuel gas used. Therefore, it is necessary to be able to set the minimum gas flow rate for each gas appliance that uses different types of fuel gas.

In the present embodiment, the first hole 5 of the first communication hole is
A bypass passage 13 that communicates 1 with the gas passage 11 is provided in the apparatus main body 12, and an orifice 14 that sets the minimum gas flow rate is inserted in the bypass passage 13.

If the second communication hole 41 does not coincide with any of the first communication holes 51, 52, 53, 54, 55, the internal passage 21 is closed and the fuel gas is supplied to the gas passage 11. It is stopped (see FIG. 2 (a)). On the other hand, the motor 3 is driven to rotate the rotary disk 4 and the second communication hole 41 is moved to the first communication hole 51, 52, 53, 53, 54, 5.
The gas flow rate is adjusted by changing the opening by matching with any one of No. 5 and No. 5.

Here, in the gas stove whose operation is electronically controlled to enhance the convenience for the cook, the heating power of the gas burner is adjusted by, for example, a light touch switch provided on the operation panel on the front of the stove. In this case, the gas valve 2 is controlled so that the thermal power of the gas burner can be set to five levels from thermal power 1 to thermal power 5, for example.

In this embodiment, when the light touch switch is pressed to set the thermal power to 1, the motor 3 is driven to rotate the rotary shaft 3
2 is rotated to one side so that the second communication hole 41 is aligned with the first hole 51 of the first communication hole. In this case, the minimum gas flow rate is such that the flame of the gas burner is not extinguished (see FIG. 2 (b)).

Next, when the touch switch is pressed to set the thermal power to 2, the motor 3 is driven to rotate the rotary shaft 32 to one side, and the second communication hole 41 is connected to the first hole 51 and the second communication hole of the first communication hole. Match the holes 52. In this case, the flow rate of the fuel gas to the gas passage 11 can be changed according to the area where the first hole 51 and the second hole 52 of the first communication hole and the second communication hole 41 coincide (FIG. 2 (c)). reference).

Then, with the thermal power 3, the second communication hole 41 is set to the first
In the second hole 52 and the third hole 53 of the communication hole (see FIG. 2D), the second communication hole 41 is changed to the third hole 53 and the fourth hole 54 of the first communication hole (see FIG. e)), in the case of thermal power 5, the second communication hole 41 is connected to the fourth hole 54 and the fifth communication hole of the first communication hole.
It is aligned with the hole 55 (see FIG. 2 (f)). Also in this case, the gas flow rate can be adjusted by changing the area of each of the holes 51 to 55 of the first communication hole which the second communication hole 41 coincides with.

Here, in the initial state, the opening degree (set thermal power) of the gas valve 2 is adjusted as follows. That is, the pressure sensor 6 described later measures the pressure of the fuel gas in the gas passage 11 at the minimum gas flow rate (thermal power 1) (hereinafter referred to as “secondary pressure”) and the secondary pressure at the maximum gas flow rate (thermal power 5). Detect each.

These secondary pressures are divided into four equal parts to calculate the secondary pressures corresponding to the thermal power 2, the thermal power 3 and the thermal power 4, and the pressure sensor 6
The motor 3 is driven to rotate the rotating disk 4 so that the detected values of 2) become the secondary pressures thereof, and the opening degree (gas flow rate) of the gas valve 2 is adjusted.

In this case, the adjusted rotating shaft 3 of the motor 3
The rotation angle of No. 2 is detected by the rotation angle detecting means 31, and the rotation angle and the secondary pressure at each heating power at that time are stored as an initial value in the microcomputer for controlling the operation of the gas stove.

For reliable ignition of the gas burner, it is preferable to rotate the rotary shaft 32 by the motor 3 to the position of the thermal power 5 at which the gas flow rate is maximized and perform the ignition operation.

Further, the gas passage 11 has the gas passage 11
A pressure sensor 6 for detecting the secondary pressure inside is provided.
The pressure sensor 6 includes a rod 62 that is inserted from a gas passage 11 into a branch passage 11 a provided in a vertical direction via a seal material 61.
And a thin resin plate (not shown) is connected to one end of the rod 62. Then, when the fuel gas is flown through the gas passage 11, the rod 11 is pushed upward by the secondary pressure, and the strain amount of the thin plate 11 at that time is detected by the strain gauge attached to the thin plate to detect the secondary pressure. .

By the way, in the gas flow control device 1, when the source pressure of the fuel gas (hereinafter referred to as "primary pressure") on the upstream side of the gas valve 2 changes, the set thermal power changes. In this case, the set thermal power is adjusted by feedback-controlling the secondary pressure detected by the pressure sensor 6 and adjusting the rotation angle of the rotary shaft 32 via the motor 3 so as to match the initial secondary pressure stored in the microcomputer. Can be adjusted, but this causes the following problems.

That is, referring to FIG. 3, when the primary pressure in the gas passage 11 fluctuates and becomes lower, and the secondary pressure in the gas passage 11 becomes lower (solid line), the secondary pressure and the initial secondary pressure. (dotted line)
There is a problem in that the heating power of the gas burner does not change even if the area where the second communication hole 41 and the first communication hole match is increased from the point B where is matched.

In the present embodiment, when the fuel gas is flowed through the gas valve 2 to the gas passage 11, the pressure sensor 6
Then, the secondary pressure is detected, and the opening of the throttle portion of the gas valve 2 is corrected according to the secondary pressure.

The correction of the opening of the throttle of the gas valve 2 will be described with reference to FIG. The motor 3 is driven to rotate the rotating disk 4 to a position where the maximum gas flow rate (thermal power 5) shown in FIG. At that time, the pressure sensor 6 detects the secondary pressure in the gas passage 11.

For example, when the primary pressure decreases, the pressure sensor 6
When the secondary pressure detected in step 2 becomes lower than the initial secondary pressure (dotted line 1), the motor 3 is driven to rotate the rotary disk 4 to a position where the minimum gas flow rate (thermal power 1) shown in FIG. The secondary pressure at that time is detected.

The detected secondary pressures at the maximum gas flow rate and the minimum gas flow rate are stored in a microcomputer, and these secondary pressures are divided into four equal parts by the microcomputer to generate thermal power 2 and thermal power 3.
Further, the opening degree is corrected by calculating and storing the secondary pressure corresponding to the thermal power 4 and the rotation angle of the rotating shaft 32 at that time.

As a result, even if the secondary pressure becomes lower than the initial secondary pressure due to the decrease in the primary pressure, the thermal power at each stage is corrected from the secondary pressure between the maximum gas flow rate and the minimum gas flow rate. The width of firepower between firepower becomes even.

On the other hand, when the secondary pressure detected by the pressure sensor 6 becomes higher than the initial secondary pressure (dotted line 2) due to, for example, the increase of the primary pressure, the correction is made based on this secondary pressure. The thermal power at thermal power 5 may become larger than necessary.

In this case, the motor 3 is driven to rotate the rotary disk 4 to a position where the minimum gas flow rate (thermal power 1) shown in FIG. 2B is reached, and the secondary pressure at that time is detected.

The secondary pressure at the detected minimum gas flow rate and the initial secondary pressure at the maximum gas flow rate are stored in the microcomputer, and the secondary pressure is divided into four equal parts by the microcomputer and the thermal power 2, thermal power 3 and thermal power are calculated. The opening degree is corrected by calculating and storing the secondary pressure corresponding to 4 and the rotation angle of the rotary shaft 32 at that time. As a result, the heating power of the gas burner does not become unnecessarily large by not using the region B shown in FIG.

Further, the gas flow rate control device 1 of the present embodiment
Then, since only the rotation angle of the rotary shaft 32 of the motor 3 is controlled based on the corrected data when the thermal power is adjusted, the rotation of the rotary shaft 32 of the motor 3 is changed from the detection value of the pressure sensor 6 each time the thermal power is adjusted. The load is not added to the CPU as compared with the case where the processing for calculating the angle and the drive control processing for the motor 3 are performed simultaneously.

When the secondary pressure detected by the pressure sensor 6 is out of the predetermined pressure range during the ignition operation of the gas burner, the microcomputer determines that the pressure sensor 6 is out of order and issues a warning. May be.

Further, as shown in FIG. 1, an electromagnetic opening / closing valve 7 may be provided in the gas passage 11 on the downstream side of the pressure sensor 6.
In this case, when the gas burner is extinguished, after closing the electromagnetic on-off valve 7, the gas valve 2 is closed to seal the gas passage, and the pressure decrease rate by the pressure sensor 6 at that time may be detected. For example, it may be possible to determine the occurrence of gas leakage from the pressure sensor 6 or the like.

In the present embodiment, the electromagnetic safety valve 7 is provided in the gas passage 11 on the downstream side of the pressure sensor 6, but the present invention is not limited to this. For example, as shown in FIG. A publicly known safety valve 8 may be provided instead.

Further, in the present embodiment, the electromagnetic safety valve 7 is provided in the gas passage 11 on the downstream side of the pressure sensor 6, and
Although the gas valve 2 is provided on the upstream side of the pressure sensor 6, the present invention is not limited to this, and the electromagnetic safety valve 7 may be provided on the upstream side of the gas valve 2 as shown in FIG.

Further, as shown in FIG. 6, a stopper 9 for limiting the rotation of the rotary shaft may be provided.

[0050]

As described above, the gas flow rate control device of the present invention does not require a CPU having a high calculation processing capacity, and moreover, even if the primary pressure changes, the thermal power between the set thermal powers of the gas burner is increased. The effect is that the width can be made uniform.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a gas flow rate control device of the present invention.

2A to 2F are views for explaining flow rate adjustment by a gas valve.

FIG. 3 is a graph illustrating gas flow rate adjustment when the primary pressure fluctuates.

FIG. 4 is a graph illustrating correction of set thermal power by the gas flow rate control device of the present invention.

FIG. 5 is a sectional view illustrating a gas flow rate control device according to another embodiment.

FIG. 6 is a sectional view illustrating a gas flow rate control device according to another embodiment.

FIG. 7 is a cross-sectional view illustrating a gas flow rate control device according to another embodiment.

[Explanation of symbols]

1 Gas flow controller 11 gas passages 2 gas valves 4 rotating discs 5 fixed disk 6 Pressure sensor

Claims (6)

[Claims] 1. A flow path adjusting means for adjusting a gas flow rate of fuel gas to the gas injection nozzle in a gas passage communicating with the gas injection nozzle, and a secondary pressure of the fuel gas downstream of the flow rate adjusting means is detected. A secondary pressure detecting means is provided, and the flow rate adjusting means changes the opening degree of the gas passage to increase or decrease the secondary pressure corresponding to the gas flow rate from the minimum gas flow rate to the maximum gas flow rate that determines the set thermal power of the gas burner. In a gas flow rate control device having a throttle portion that performs, a fuel gas is caused to flow in a gas passage through the flow rate adjusting means,
The secondary pressure is detected by the secondary pressure detection means, and the opening of the throttle portion corresponding to the gas flow rate that determines each set thermal power is corrected from the detected secondary pressure, and the gas is opened at the corrected opening of the throttle portion. A gas flow rate control device, characterized in that it controls the heat power of a burner. 2. The gas flow rate control device according to claim 1, wherein the secondary pressure is detected for each of the minimum gas flow rate and the maximum gas flow rate by changing the opening of the throttle portion. 3. The detection of the secondary pressure is performed for the maximum gas flow rate by changing the opening of the throttle part, and when the detected secondary pressure becomes higher than the initial secondary pressure, the throttle part is changed from the initial secondary pressure. The gas flow rate control device according to claim 1, wherein the opening degree of the gas flow rate is corrected. 4. The method according to claim 1, wherein when the detected secondary pressure is out of a predetermined pressure range, a warning of the failure of the secondary pressure detecting means is issued. The gas flow rate control device according to item 1. 5. The gas flow rate control device according to claim 1, wherein the flow rate control means has a closing function. 6. An on-off valve is provided between the secondary pressure detecting means and the gas injection nozzle, and when the supply of fuel gas to the gas injection nozzle is stopped, the on-off valve is closed before the flow rate adjusting means. The gas flow rate control device according to claim 5, wherein the pressure decrease rate is detected by the detection means.