JPH11351412A - Gas flow adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas flow adjusting device which can stabilize the medium ignition or medium combustion of a gas burner. SOLUTION: A needle part 9 is arranged at the end of a valve element 6, and a circumferential groove 11 is arranged in the middle of the needle part 9. A variable throttle passage 12 is arranged between the needle part 9 and a valve hole 4, and an intermediate passage 14 and a normally opened passage 15 which communicate with a center hole 13 are opened. A large amount of gas is led to flow from the passages 12, 14, 15 in the upper position of the valve element 6, a middle amount of gas is led flow from the passages 14, 15 in the intermediate position thereof, and a small amount of gas is led to flow only from the passage 15 in the lower end position thereof. The middle amount of gas is led to flow by an approximately constant flow during a period unless the circumferential groove 11 penetrates into the valve hole 4, therefore medium ignition or medium combustion can be stably performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas flow control device capable of controlling a gas flow over a wide range. The present invention relates to a gas flow control device capable of obtaining a stable medium fire as well as being able to obtain a medium heat.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional gas flow controller of this type. In FIG. 7, a
Is a housing, a1 is a valve chamber, a2 is a valve hole, and a3 is a flow path. Needle part b is provided at the tip end of valve body b through step b1.
2, a normally open passage b5 communicates via an orifice b4 provided in a center hole b3, and a seal packing c is interposed between the valve chamber a1 and the valve body b. In this gas flow control device, a variable throttle passage d is formed between the valve hole a2 and the needle portion b2, and the valve body b is moved by a lever (not shown).
When the pressure is decreased, the throttle in the variable throttle passage d increases, and finally the step b1 closes the valve hole a2, while the orifice b4 remains open.

[0003] When this gas flow control device is used for a burner, the needle portion b2 has a valve hole a2 on the burner side.
When it is outside, high heat is generated and the needle part b2 is
When the step portion b1 closes the valve hole a2, the weakest fire is caused by gas passing only through the orifice b4.

However, in this type of gas flow control device, the degree of opening of the variable throttle passage d with respect to the lever position varies due to the hysteresis between the forward and backward movements of the valve body b by the lever, particularly at the intermediate position. This causes a change in the gas amount even at the same lever position.

FIG. 8 shows the relationship between the lever position and the gas flow rate. The curve A1 that decreases the opening from the maximum opening and the curve B1 that increases the opening from the minimum opening are:
Even at the same intermediate position, there is a difference in the gas amount of the difference H between the intersection X of the line A and the curve A1 and the intersection Y of the line A and the curve B1.

[0006] Therefore, when attempting to ignite at this intermediate position, a large flame may be generated and the ignition may be surprised, or the ignition may be difficult due to a small amount of gas.

[0007] Alternatively, in a gas stove with a rice cooker function in which a gas stove is provided with a rice cooker function capable of reducing the amount of gas from large heat to small heat, it is necessary to set the amount of gas to be cooked with a lever during cooking in order to cook delicious rice. is there. If the gas flow control device is used for the gas stove, if the setting position of the lever is slightly shifted, the gas amount is not set correctly, which may affect the rice cooking performance.

Although the above description has been made with reference to the example of the change in the gas amount due to the hysteresis, the same may occur due to the variation in the position where the valve body is assembled to the lever.

Therefore, as shown in FIG.
If a cylindrical portion b21 having a length L is provided in the middle in the axial direction of the valve hole, the same diameter portion and the opening are equally spaced while the same diameter b21 is at the mouth of the valve hole a2. Because there is, needle part b2
Even if there is a misalignment due to the structure, hysteresis,
The gas volume is not expected to change.

[0010] However, while the same-diameter portion is at the mouth, the interval between the same-diameter portion and the mouth portion is equal, but when the tip side of the same-diameter portion is located at the mouth portion of the valve hole a2, the same as in the case where The root side of the diameter is the valve hole a
The gas amount is different from that in the case of being located at the mouth of No. 2. This is because the flow resistance is affected by the difference in the overlapping length between the same diameter portion b21 and the valve hole a.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas flow control device capable of controlling strong, medium and weak heating power without being affected by hysteresis or the like.

[0012]

Means for Solving the Problems According to the first aspect of the present invention, a valve chamber is provided in a housing, and a gas is supplied from the valve chamber to the housing. A valve hole concentric with the valve chamber and having a smaller diameter than the valve chamber and a flow path communicating with a side portion of the valve chamber are provided on the upstream side in the flow direction of the flow. A needle portion forming a variable throttle passage protrudes between the valve member and a normally open passage from the center hole opened from the tip of the needle portion to the valve body surface to the valve body surface. In the gas flow rate adjusting device for adjusting the flow rate, a peripheral groove is provided on the distal end side of the normally open passage in the needle portion, and an intermediate passage is provided between the center hole and the peripheral groove.

According to this means, in the vicinity of the maximum opening of the gas flow control device, the gas having the maximum opening is the sum of the variable throttle passage, the intermediate passage having a constant area, and the normally open passage. Gas volume flows. At the intermediate position where the needle portion enters the valve hole, the amount of gas passing through the variable throttle passage and its change are small until the entire circumferential groove is hidden by the valve hole, and the amount of gas passing through the intermediate passage and the normally open passage is small. Since the total is constant, the gas amount as a whole is substantially constant even if there is a slight difference in the position of the valve element. Therefore, when this gas flow control device is used for a burner, stable medium-fire ignition can be performed.

According to a second aspect of the present invention, the housing is provided with a valve hole concentric with the valve chamber and a flow path communicating with a side portion of the valve chamber. At the tip, a needle portion that forms a variable throttle passage between the valve hole and the valve hole protrudes, and a normally open passage from the center hole opened over the valve body from the needle portion tip to the valve body surface is provided. In the gas flow control device provided with an operation mechanism consisting of a cam and a lever, a peripheral groove is provided in the middle of the needle portion, and a bypass-shaped intermediate portion passing through the needle portion is provided between the distal end surface of the needle portion and the peripheral groove. A passage is provided.

In this means, the position and structure of the intermediate passage are different from those of the first aspect, but the operation is the same.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a gas flow control device, 2 denotes a housing thereof, and a valve chamber 3 and a valve hole 4 having a smaller diameter than the valve chamber 3 are formed concentrically upstream of the gas flow from the valve chamber 3. The flow path 5 is opened at the side of. The valve body 6 is provided with a large-diameter portion 7 having a diameter larger than the valve hole 4, and a needle portion 9 is projected from the large-diameter portion 7 via a step 8. As shown in FIG. 3, the needle portion 9 has a tip needle portion 9 a and a root side needle portion 9 b divided by the circumferential groove 11, and the diameter of the root portion 9 c connected to the step 8 is smaller than the inner diameter of the valve hole 4. Both needle portions 9a and 9b are tapered slightly toward the distal end. The taper angle can be changed, for example, in the range of about 1 to 10 degrees depending on the gas type and gas consumption.

The distal end side variable throttle portion 12a formed between the distal end needle portion 9a on the distal end side of the peripheral groove 11 of the needle portion 9 and the mouth portion 4a is connected to the distal end portion 9a of the distal end needle portion 9a.
The degree of aperture is changed depending on the degree of approach to a. In addition, the root side needle portion 9 on the root side from the circumferential groove 11 of the needle portion 9
root-side variable throttle section 12 formed between b and the mouth 4a
As for b, the degree of squeezing is changed by the degree of entry of the root side needle portion 9b into the mouth 4a.

The needle portion 9 has a large diameter portion 7 from its tip.
The center hole 13 is opened to the back of the
1, an intermediate passage 14 is formed between the center hole 13 and the peripheral surface of the large-diameter portion 7. The circumferential groove 11 has a groove width w in the axial direction as shown in FIG. 3, and the groove edge 11 of the tip needle portion 9 a in contact with the circumferential groove 11.
a and the radius of the groove edge 11b of the root side needle portion 9b are the same radius r. For this reason, the valve element 6 descends and the circumferential groove 11
From the start of entering into the valve hole 4 to the end thereof, the tip-side variable restrictor 12a maintains the state of the maximum restriction in the first half,
Next, when the circumferential groove 11 is completely inserted into the valve hole 4, the root-side variable throttle portion 12b starts to operate, and a throttle that is larger than the former half of the throttle action is generated.

In FIG. 1, 16 is an O-ring for sealing,
Reference numeral 17 denotes a driven pin, and the driven pin 17 is operated by a lever 18 shown in FIGS. The lever 18 has a crank shape, and has a base end pivotally attached to a metal fitting 19 integrated with the housing 2 with a rivet 19a, and has a vertical groove 18a in a vertical portion. A cam 20 having an inclined cam groove 20a is provided in the housing 2.
Is fixed, and the pin 17 is fixed to the valve body 6 through the cam groove 20a and the vertical groove 18a. Therefore, lever 18
Is rotated, the pin 17 moves along the cam groove 20a, and the valve body 6 moves up and down. Further, an ignition device (not shown) is provided so as to operate at the middle fire position of the lever 18.

Then, as shown in FIG. 4 (A), the valve element 6 is located above, and the distal end of the distal needle portion 9a starts to enter the mouth portion 4a.
When the normally open passages 15 are all open, each passage is
1, g2 and g3 flow and a large amount of gas is supplied to the burner to generate a strong fire. Thereafter, as the distal needle portion 9a enters the mouth 4a (line 4a1 in FIG. 3), the distal variable throttle passage 12a gradually narrows, and the gas g1 gradually decreases, but the gas g2 and g3 are basically changed. It does not change. Therefore, the amount of gas flowing through the flow path 5 gradually decreases.

The tip side needle portion 9a is connected to the mouth portion 4a.
End (line 4a2 in FIG. 3) and then FIG. 4 (B)
As shown in FIG. 3, the circumferential groove 11 enters the mouth 4a (lines 4a2 to 4a4 in FIG. 3). The groove width w of the peripheral groove 11 is equal to the opening 4a.
In other words, even if the needle 9 moves into the peripheral groove 11
Even if it moves into the mouth portion 4a by the groove width w, the throttle of the gas amount hardly changes, and the gas enters an equilibrium state.

This is because of the groove edge 1 on the front end side of the groove width w of the peripheral groove 11.
The thickness of the needle portion 1a is the same as that of the needle portion at the root side groove edge 11b, and the gas passing through the center hole 13 and passing through the intermediate passage 14 is not affected by the distance between the front end side groove edge 11a and the mouth 4a. This is because it comes out of the gap with the mouth 4a.

Next, after the root-side needle portion 9b has entered the mouth portion 4a (after passing through the mouth portion 4a4 in FIG. 3), even if there is gas passing through the center hole 13 and passing through the intermediate passage 14, the root portion needle portion 9b will not. The gas amount is limited by the variable throttle 12b formed at the interval between the side needle 9b and the mouth 4a.

When the step portion 8 comes into contact with the mouth portion 4a as shown in FIG. 4C, only the gas g ₃ having the minimum flow rate through the center hole 13 and the normally open passage 15 flows, and a complete low heat is generated. Become. In order to secure this minimum flow rate, an orifice corresponding to the amount of gas flowing through the normally open passage 15 is provided in the center hole 13 like the conventional orifice b4 in FIG. It may be a communication passage through which the gas can flow.

FIG. 5 shows the change in the gas flow rate with respect to the position of the lever 18. Curves A and B show the limit of the variation in the operation of the product or the hysteresis at the time of opening and closing.
During the middle fire when the circumferential groove 11 is open as in (B), the sum of the amounts of the gases g2 and g3 passing through the intermediate passage 14 and the normally open passage 15 is constant, and the gas g1 passing through the variable throttle passage 12 is constant. , The curve indicating the sum of the gas amounts has a gentle slope and the difference h in the gas amount at the position of the straight line a.
Is small.

For this reason, even if there is a variation in the assembly of the gas flow control devices or there is a hysteresis, the difference between the gas amounts of the gas flow control devices is small when the straight line A is set to the medium ignition position. Is the ignition position, there is almost no difference in the size of the flame at the time of ignition. Further, even if the position of the straight line a is slightly shifted left and right, the difference h is small, so that there is almost no difference in the size of the flame. This means that almost the same amount of gas can be obtained even when the position of A is the position of the amount of cooked gas, so that there is no difference in the cooked state.

FIG. 6 shows another embodiment of the valve body 6, in which a groove-shaped intermediate passage 14a is provided in a part of the peripheral surface of the needle portion 9 instead of the intermediate passage 14 of the previous embodiment. . The operation of the intermediate passage 14a is the same as the operation of the intermediate passage 14.

[0028]

As described above, according to the gas flow control device of the first and second aspects, the peripheral groove of the needle portion is provided at the intermediate position of the valve body even if the position of the valve body with respect to the housing varies. There is an effect that the gas flow rate can be stably maintained at a substantially constant medium amount from the time when the gas enters the hole to the time when the gas enters the hole. Therefore, when this gas flow control device is used for a burner, it is possible to generate a medium fire of a substantially constant size, to perform stable medium fire ignition, or to set an appropriate rice cooking gas amount. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is a perspective view of an operation unit.

FIG. 3 is an enlarged view of a main part of a valve body.

FIG. 4 is an explanatory view of the operation of the valve body.

FIG. 5 is a graph showing a change in flow rate.

FIG. 6 is a perspective view of another form of the valve body.

FIG. 7 is a longitudinal sectional view of a conventional example.

FIG. 8 is also a graph showing a change in flow rate.

FIG. 9 is a longitudinal sectional view of a reference example.

[Explanation of symbols]

Reference Signs List 2 housing 3 valve chamber 4 valve hole 4a mouth 6 valve body 7 stepped portion 8 large diameter portion 9 needle portion 11 peripheral groove 12 variable throttle passage 13 center hole 14, 14a intermediate passage 15 normally open passage

Claims (2)

[Claims] A flow communicating with a valve chamber, a valve hole smaller in diameter than the valve chamber and concentric with the valve chamber upstream of the valve chamber in the gas flow direction, and a side of the valve chamber. A needle is formed at the tip of the valve body that moves forward and backward in the valve chamber, and a needle part that forms a variable throttle passage between the valve body and the valve hole is provided. In a gas flow control device that provides a normally open passage that extends and retracts the valve body into and out of the valve hole to adjust the gas flow rate, a peripheral groove is provided on the distal end side of the normally open passage in the needle portion, and a center hole and a peripheral groove are formed. A gas flow control device, wherein an intermediate passage for communicating these is provided between them. 2. A housing having a valve hole concentric with the valve chamber and a flow path communicating with a side portion of the valve chamber. A variable throttle passage is provided between the valve hole and the distal end of the valve body which advances and retreats in the valve chamber. A needle portion to be formed is protruded, a normally open passage from a center hole opened from the tip of the needle portion to the valve body to the valve body surface is provided, and an operation mechanism including a cam and a lever is provided between the housing and the valve body. In the gas flow control device, a peripheral groove is provided in the middle of the needle portion, and a bypass-shaped intermediate passage passing through the needle portion is provided between the distal end surface of the needle portion and the peripheral groove. .