JPS643025Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a gas solenoid valve used in a gas water heater or the like.

Recently, solenoid valves have been widely used as on-off valves for gas appliances such as gas water heaters, gas baths, gas cookers, and gas stoves. For safety reasons, two solenoid valves are usually used in series, so that if one fails, the other will stop the gas flow.
FIG. 1 shows a typical structure when two conventional solenoid valves are used. That is, the first and second solenoid valves are provided independently, and the outlet opening of the first solenoid valve and the second solenoid valve are independent of each other.
It has a structure in which the inlet opening of the solenoid valve is connected with an L-shaped pipe. The first and second solenoid valves are opened or closed simultaneously by opening and closing a common switch. Even if the first solenoid valve fails, the second solenoid valve can stop the gas, ensuring safety. However, the conventional structure described above requires two solenoid valves of the same structure, which has the disadvantage of increasing costs. Another disadvantage is that the number of bends and connections in the gas passage increases, and piping resistance also increases.
Furthermore, it is larger overall and has less freedom in terms of ceremonial equipment.

The purpose of the present invention is to solve the above-mentioned conventional drawbacks,
To provide a gas solenoid valve that drives two valves with one solenoid, ensures safety against gas leakage, etc., and is simple in structure, inexpensive, and compact.

The valve of the present invention includes a plunger that is attracted when a coil is energized, a valve rod that is fixed or locked to the central axis of the plunger, and first and second valves that are successively fixed or locked to the valve rod. , two annular projections having first and second seat surfaces that protrude continuously in an annular shape from the inner periphery of the gas passage and can come into close contact with the first and second valves from the upstream side; and first and second springs that bias the second valve toward the first and second seats, respectively, the first valve and the first seat pushing the first valve portion. configure,
The second valve and the second seat constitute a second valve portion.

Further, if at least one of the valves is made slidable on the valve rod, high precision is not required in manufacturing the valve, and it is also advantageous in terms of safety.

Furthermore, the sliding stroke of the first and second valves, the distance between the first and second valves, and the first,
By setting the distance between the second sheets to satisfy predetermined conditions, the reliability and safety of the operation can be further improved. Further, airtightness can be easily ensured if the valve can be locked without drilling a sliding hole.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a sectional view showing an embodiment of the present invention. That is, the coil 3 is wound around the plunger 1 and the inner yoke 2, and the outside of the coil 3 is surrounded by the outer yokes 5 and 6 to form a magnetic path. A valve rod 4 is fixed coaxially to the tip of the plunger 1, and a part of the valve rod 4 is made thin so that a first valve 7 and a second valve 8 are successively provided and slidably held. A case 9 is provided coaxially surrounding the valves 7 and 8, and the lower end of the case 9 in the figure is closely fixed to the outer yoke 5. Case 9 constitutes a gas passage. Two annular protrusions 10 and 11 are provided on the inner periphery of the case 9.
are provided in succession, and the surfaces facing the valves 7 and 8 on the upstream side of each protrusion, that is, the seats 10a and 11a, can be brought into airtight contact with the valves 7 and 8. That is, the valve 7 and the seat 10a constitute a first valve section, and the valve 8 and the seat 11a constitute a second valve section. When the valves 7 and 8 are pressed by springs 12 and 13, respectively, they come into close contact with the seats 10a and 11a, respectively, and close the gas flow path. When the coil 3 is energized, the plunger 1 is attracted to the inner yoke 2 (the position shown), and the valves 7 and 8 are moved to the seats 10a and 10 against the urging force of the springs 12 and 13.
1a to open the gas flow path. When the gas flow path is opened, gas flows into the case 9 from the inlet on the left side in the figure, flows out from the outlet on the upper side in the figure, and is guided to a gas appliance or the like (not shown). In this example, 1
Because two solenoids can drive two valves 7 and 8 at the same time and open and close two valves,
There is no need to separately provide two solenoid valves as in the past, and it can be made smaller, and
There is no need for a connecting pipe or the like to connect two solenoid valves, which has the effect of reducing bending angles, joints, etc. In addition, since the valves are opened and closed independently by two valves, even if one valve fails and the gas flow path cannot be completely closed,
Safety is ensured because the gas flow path can be closed by the other valve. Furthermore, the first
The second valve 7 and the second valve 8 are each slidably held by the valve rod 4 and are pressed by separate springs 12 and 13, so the mounting positions of the valves do not need to be highly accurate. Furthermore, the independence of the two valves is ensured. That is, even if one valve or spring is damaged, a gas seal is ensured by the other. A similar effect can be obtained by fixing one valve to the valve rod and slidingly holding the other valve. As shown in FIG. 3, when the valves 7 and 8 are respectively locked at the distal end side of the rod 4, the distance between the valves 7 and 8 is _l1 , and the distance between the seats 10a and 11a is l. ₂
If the stroke length in which valve 7 can slide is α, and the stroke length in which valve 8 can slide is β, then if l ₁ > l ₂ then l ₁ − (α − β) ≦ l ₂ It should be formed or adjusted so that α>0 β≧0, and if l ₁ < l ₂ , it should be formed or adjusted so that l ₁ + (β−α)≧l ₂ α≧0 β>0. For example, independent gas sealing performance is ensured by the two valves. The above adjustment can be easily carried out by adjusting the interference between the valve and the valve rod. If l ₁ > l ₂ in the above, the valve 8 is fixed to the valve rod 4, and the sliding distance α of the valve 7 is α≧l ₁ −l ₂ , then the valve 8 is fixed to the valve rod 4 before the valve 8 comes into contact with the seat 11a. to valve 7
The first valve is closed by the seat 10a, and then the valve 8 is pressed against the seat 11a by the urging force of the spring 13, and the second valve is closed. In the case of l ₁ < l ₂ , conversely, the valve 7 is fixed to the valve rod 4, and the sliding stroke β of the valve 8 is
If β≧l ₂ −l ₁ , the valve 8 is first pressed against the seat 11a by the urging force of the springs 12 and 13, and the second valve is closed, and then the spring 12
The valve 7 is pressed against the seat 10a by the urging force. In any of the above cases, the closing force of the first valve part and the closing force of the second valve part are provided by the springs 12 and 13, respectively, and have the advantage that they are independent of each other and are not influenced by others. be. One of the springs 12 or 13 described above, for example spring 12, may be interposed between the valve 7 and a retaining ring (not shown) that is tightly fitted to the valve rod 4; in this case, the spring 7 The valve rod is urged downward in the figure, and the spring 13
Since the upward biasing force in the figure is weakened by the biasing force of the spring 13, the biasing force of the spring 13 must be made stronger than the biasing force of the spring 12. Further, the closing force of the first valve portion and the closing force of the second valve portion are not independent from each other. In this embodiment, the spring 12 is interposed between the annular protrusion 11 protruding from the inner periphery of the case 9 and the valve 7, so that the urging force of the spring 12 weakens the urging force of the spring 13. As mentioned above, a completely independent closing force can be obtained. The spring 13 is interposed between the valve 8 and a cup-shaped base (the bottom center of which has a hole through which the valve rod is inserted) fixed to the outer yoke 5. If the valves 7 and 8 are both fixed to the valve rod, it goes without saying that the distance between the valves must exactly match the distance between the seats. That is, although high dimensional accuracy is required, in this embodiment, the dimensional accuracy does not need to be so high, so manufacturing and adjustment are easy and the cost is low.

Also, to open the flow path by suctioning the valve,
Conventional solenoid valves require a suction force to overcome the gas pressure applied to the back of the valve, so if the first solenoid valve is defective, the second solenoid valve
Back pressure is applied to the first solenoid valve, and if the second solenoid valve is defective, back pressure is applied to the first solenoid valve. Therefore, both solenoid valves require the same level of suction force. In the example case, the back pressure on either side can be ignored. For example, when the gas seal of the first valve 7 is defective, back pressure is applied only to the second valve 8, and when the gas seal of the second valve 8 is defective, back pressure is applied only to the first valve 7. There's pressure. Therefore, the suction force of the solenoid only needs to be small since it is sufficient to consider the back pressure on one side. That is, in order to drive two valves, the suction force for two valves is not required, so the solenoid does not become large. Furthermore, since the two valves are arranged coaxially within the same case, the number of bends in the gas flow path can be reduced and the number of joints etc. can be kept to a minimum. Piping resistance is also small,
It is possible to provide small size and low cost.

FIG. 4 shows another embodiment of the invention. That is, the second valve 8 is fixed to the valve rod 4' connected to a plunger (not shown), and the valve 8 is connected to the valve rod 4'.
A connecting rod 4'' is fixed at the center of the valve rod 4' and 4'' may be formed by a single rod through which the valve 8 is inserted and fixed. Also, valve rod 4',
4'' may be simply locked without being fixed to the valve 8. Then, a locking part 4a for locking the valve 7 is provided at the tip of the connecting rod 4'', and the first valve 7 is provided with a locking part 4a for locking the valve 7. 4a is provided. In this case, the rods 4', 4'', etc. do not need to slide and hold the valves 7, 8, etc., so there is no risk of gas leaking from the sliding parts.In other words, it is easier to maintain airtightness and machining is easier. This has the advantage of being simple. When the valve rod 4' is pulled downward in the figure, the second valve 8 opens the valve, and the rod 4'' opens the first valve 7 by the locking part 4a. Of course you can. Spring 12 at all times,
13, the first valve 7 and the second valve 8 are closed independently. In addition, the locking parts 7a, 4a
The shape etc. of can be variously modified.

As described above, in the present invention, one solenoid is configured to attract two valves to open each valve, and each valve is pressed by a separate spring to close the valve. Therefore, safety can be ensured by using two valves, and it can be provided in a small size and at low cost. In addition, piping resistance can be reduced, and the number of bends, joints, etc. in the gas flow path can be reduced compared to the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of two conventional solenoid valves connected in series, Fig. 2 is a cross-sectional view showing an embodiment of the present invention, and Fig. 3 is the spacing between the seats of the above embodiment. , a diagram for explaining the relationship between the valve interval and the valve sliding stroke, and FIG. 4 is a partially sectional view showing another embodiment of the present invention. In the figure, 1... Plunger, 2... Inner yoke, 3... Coil, 4, 4'... Valve rod, 5, 6... Outer yoke, 7... First valve, 8... Second valve. , 9...Case, 1
0, 11...Annular protrusion, 10a...First seat, 11a...Second seat, 12...First spring, 13...Second spring, _l1 ...Distance between valves, l ₂ ... Distance between seats, α ₁ ... Sliding stroke of the first valve, α ₂ ... Sliding stroke of the second valve, 4'' ... Connection rod, 4a,
7a...Locking part.

Claims (1)

[Claims for Utility Model Registration] (1) A plunger that is attracted when a coil is energized, a valve rod that is fixed or locked to the central axis of the plunger, and a first valve rod that is fixed or locked in succession to the valve rod. and a second valve, and two annular protrusions having first and second seat surfaces that protrude continuously into the gas passage and allow the first and second valves to come into close contact with each other from the upstream side, respectively. , first and second springs biasing the first and second valves toward the first and second seats, respectively; A solenoid valve for gas, comprising a valve portion, and the second valve portion and the second seat constitute the second valve portion. (2) Utility Model Registration The gas solenoid valve according to claim 1, characterized in that at least one of the first and second valves is slidably held by the valve rod. (3) Utility model registration In the gas solenoid valve according to claim 2, the sliding stroke of the first valve is α, the sliding stroke of the second valve is β, and the first and The distance between the first and second valves when the second valves are respectively locked by the distal end side locking portions of the valve rod is _l1 , and the distance between the first and second seats is _l2 . If l ₁ > l ₂ , then
At least α is not zero and satisfies the relationship l ₁ − (α − β) ≦ l ₂ , and when l ₁ < l ₂ , at least β is not zero and l ₁ + (β − α) ≧ l ₂ A characteristic that satisfies the relationship of (4) Utility model registration The gas solenoid valve according to claim 1, further comprising a connecting rod that is fixed or locked to the second valve and that locks the first valve, 1st
The valve of the invention is characterized in that the valve does not have a hole through which the valve rod or the connecting rod is inserted, and is respectively locked or fixed to the rod.