Electric fire damper

Abstract

The present invention provides an electric fire damper, which includes: a main valve body (2) capable of freely moving in the closing direction approaching the valve seat and the opening direction away from the valve seat, a sub-valve body opposed to the main valve body in the opening direction, a direct-acting body abutting against the sub-valve body from the opening direction, and a stepping motor for driving the direct-acting body. The main valve body has: a bypass hole (24) for allowing gas to flow from the upstream side to the downstream side of the main valve body even in the state of being seated on the valve seat, and a sub-valve seat (25) for opening the bypass hole. It can be switched to a fully closed state where the main valve body is seated on the valve seat and the sub-valve body is seated on the sub-valve seat, and poor sealing in the fully closed state can be prevented. A gasket (32) made of an elastic material is installed on the sub-valve body, and the sub-valve body is seated on the sub-valve seat at the position of the gasket. And when the stepping motor loses steps and performs origin return in the fully closed state, the valve body (31) of the sub-valve body formed of a hard material is brought into contact with the sub-valve seat.

Description

Technical Field

[0001] The present invention relates to an electric fire intensity regulating valve provided on a gas supply path for supplying gas to a stove burner. Background Art

[0002] As is well known, in the past, according to Patent Document 1, as such an electric fire intensity regulating valve, there is provided: a main valve body that is disposed in a valve chamber within a valve housing so as to be movable freely in a closing direction approaching a valve seat at one end in the valve chamber and an opening direction away from the valve seat; a sub-valve body that is opposed to the main valve body in the opening direction; a first biasing mechanism that biases the main valve body in the opening direction; a second biasing mechanism that biases the sub-valve body in the opening direction relative to the main valve body with a force stronger than that of the first biasing mechanism; a stopper mechanism that restricts the movement of the sub-valve body in the opening direction relative to the main valve body to a fixed position; a direct-acting body that abuts against the sub-valve body from the opening direction; and a stepping motor that drives the direct-acting body in the opening direction and the closing direction by means of a linkage mechanism. In this electric fire intensity regulating valve, the main valve body has: a bypass hole that allows gas to flow from the upstream side to the downstream side even when the main valve body is seated on the valve seat, and a sub-valve seat on which the sub-valve body can be seated and that allows the bypass hole to be open. Further, it is possible to switch to a fully closed state in which the main valve body is seated on the valve seat and the sub-valve body is seated on the sub-valve seat, thereby stopping the gas supply to the stove burner.

[0003] However, in the gas stove described in Patent Document 1, the sub-valve seat is formed in the main body portion of the main valve body formed of a hard member, and the entire sub-valve body is formed of a hard member. Therefore, even when the sub-valve body is seated on the sub-valve seat in the fully closed state, since it is the contact between hard members, the gas flowing into the bypass hole cannot be completely blocked, resulting in poor sealing in the fully closed state.

[0004] Patent Document

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015 - 129626 Summary of the Invention

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide an electric fire intensity regulating valve capable of preventing poor sealing in the fully closed state.

[0007] In order to solve the above problems, an electric flame control valve provided on a gas supply path for supplying gas to a stove burner includes: a main valve body disposed in a valve chamber within a valve housing so as to be movable freely in a closing direction approaching a valve seat at one end in the valve chamber and an opening direction away from the valve seat; a sub-valve body opposed to the main valve body in the opening direction; a first biasing mechanism that biases the main valve body in the opening direction; a second biasing mechanism that biases the sub-valve body in the opening direction relative to the main valve body with a force stronger than that of the first biasing mechanism; a stopper mechanism that restricts the movement of the sub-valve body in the opening direction relative to the main valve body to a fixed position; a direct-acting body that abuts against the sub-valve body from the opening direction; and a stepping motor that drives the sub-valve body in the opening direction and the closing direction via a linkage mechanism. The main valve body has: a bypass hole that allows gas to flow from the upstream side to the downstream side of the main valve body even when the main valve body is seated on the valve seat, and a sub-valve seat on which the sub-valve body can be seated and that makes the bypass hole open. Moreover, it is possible to switch to a fully closed state in which the main valve body is seated on the valve seat and the sub-valve body is seated on the sub-valve seat. It is characterized in that: a gasket made of an elastic material opposed to the sub-valve seat is installed on the sub-valve body, and the sub-valve body is seated on the sub-valve seat at the gasket position.

[0008] According to the electric flame control valve of the present invention, different from the contact between hard components in the above conventional example, in the fully closed state, since the gasket made of an elastic material provided on the sub-valve body is seated on the sub-valve seat provided on the main valve body, it is possible to surely prevent a sealing defect in the fully closed state.

[0009] However, when performing the home position return of the stepping motor, sometimes the stepping motor may lose steps in the fully closed state. But when, as in the present invention, the sub-valve body is seated on the sub-valve seat at the gasket position made of an elastic material in the fully closed state, an uneven compression condition of the gasket may occur when losing steps, resulting in an uncertain home position of the stepping motor.

[0010] Therefore, in the present invention, preferably, the sub-valve body includes a valve body formed of a hard material. The valve body has: a hollow portion that is open at a front end of the valve body opposed to the sub-valve seat. The gasket is installed in the hollow portion in such a manner that a front end portion of the gasket opposed to the sub-valve seat protrudes from the front end of the valve body by a specified compression amount. When losing steps during the home position return in the fully closed state, the amount of compression of the gasket is the above-specified compression amount, so that the front end of the valve body abuts against the sub-valve seat. Accordingly, it is possible to fix the home position of the stepping motor without being affected by an uneven compression condition of the gasket, and based on this home position, the flame can be accurately adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a sectional side view of the electric flame control valve according to an embodiment of the present invention.

[0012] Figure 2 This is a perspective view of an exploded state of the main part of the electric type fire damper of the embodiment.

[0013] Explanation of reference numerals

[0014] A... Electric type fire damper, B... Burner, G... Gas supply path, 1... Valve housing, 13... Valve chamber, 14... Valve seat, 2... Main valve body, 25... Sub - valve seat, 3... Sub - valve body, 31... Valve body proper, 31a... Hollow part, 32... Gasket, 32a... Front end part of the gasket, 41... First biasing mechanism, 42... Second biasing mechanism, 5... Stopping mechanism, 6... Direct - acting body, 7... Linkage mechanism, 8... Stepper motor. Detailed implementation mode

[0015] Refer to Figure 1 , A is the electric type fire damper of the embodiment of the present invention provided on the gas supply path G for supplying gas to a burner such as a stove burner. This fire damper A includes a valve housing 1, and the valve housing 1 has: an inlet 11 and an outlet 12 respectively connected to the upstream side part and the downstream side part of the gas supply path G, and provided in the valve housing 1 are: a valve chamber 13 communicating with the inlet 11, and a valve seat 14 at one end of the valve chamber 13. An orifice 15 communicating with the outlet 12 is opened on the valve seat 14.

[0016] Refer to Figure 2 , the electric type fire damper A includes: a main valve body 2 which is arranged in the valve chamber 13 so as to be able to move freely in the closing direction approaching the valve seat 14 ( Figure 1 right side), and the opening direction away from the valve seat 14 ( Figure 1 left side); a sub - valve body 3 which is opposed to the main valve body 2 in the opening direction; a first biasing mechanism 41 which biases the main valve body 2 in the opening direction; a second biasing mechanism 42 which biases the sub - valve body 3 in the opening direction relative to the main valve body 2 with a force stronger than that of the first biasing mechanism 41; a stopping mechanism 5 which stops the movement of the sub - valve body 3 in the opening direction relative to the main valve body 2 at a fixed position; a direct - acting body 6 which abuts against the sub - valve body 3 from the opening direction; and a stepper motor 8 which drives the direct - acting body 6 in the opening direction and the closing direction through a linkage mechanism 7.

[0017] The main valve body 2 includes a valve body 21 formed of a hard material such as hard resin. In the valve body 21, there is provided a needle body portion 22 that can be inserted into the valve hole 15. Fixed to the outside of the valve body 21 is an annular sealing portion 23 that can be seated on the valve seat 14 and is formed of an elastic material such as rubber, and the annular sealing portion 23 is prevented from falling off by an edge portion 22 formed at the opening direction end of the needle body portion 22. Further, in the valve body 21, there are formed a bypass hole 24 that allows gas to flow from the upstream side to the downstream side of the main valve body 2 even when the main valve body 2, that is, the sealing portion 23, is seated on the valve seat 14, and a sub-valve seat 25 on which the sub-valve body 3 can be seated and that allows the bypass hole 24 to be open. In the bypass hole 24, there is provided a pinhole portion 24a that defines the minimum flame of the burner, and at the opening direction end of the valve body 21, there is joined a guide cylinder portion 26 formed of a hard material and extending in the opening direction so as to surround the sub-valve body 3. On the outer peripheral surface of the guide cylinder portion 26, there are protruding a plurality of ridges 26a that slidably contact the peripheral wall surface of the valve chamber 13. Additionally, at the base end portion of the guide cylinder portion 26, there is formed a through hole 26b that communicates the inside and outside of the guide cylinder portion 26.

[0018] The sub-valve body 3 is provided with a gasket 32 made of an elastic material such as rubber that faces the sub-valve seat 25. And the sub-valve body 3 is seated on the sub-valve seat 25 at the position of the gasket 32. If described in more detail, the sub-valve body 3 has a valve body 31 formed of a hard material such as hard resin. The valve body 31 has a hollow portion 31a that is open at the front end of the valve body 31 facing the sub-valve seat 25. The above-mentioned gasket 32 is installed in the hollow portion 31a. As Figure 2 shown, in the free state, the front end portion 32a of the gasket 32 facing the sub-valve seat 25 protrudes from the front end portion of the valve body 31 facing the sub-valve seat 25 by a specified amount of compression. Further, in the present embodiment, although the gasket 32 is installed in the hollow portion 31a during the injection molding in the formation of the valve body 31, it is also possible to install the gasket 32 in the hollow portion 31a in an embedded manner after the formation of the valve body 31. In this case, an adhesive can be applied between the valve body 31 and the gasket 32, and then the two can be joined. In addition, the sub-valve body 3 is provided with a guide portion 33 that is integral with the valve body 31, and the guide portion 33 slidably contacts the inner peripheral surface of the guide cylinder portion 26 of the main valve body 2.

[0019] The stopper mechanism 5 is composed of a window hole 51 formed in the guide cylinder portion 26 of the main valve body 2 and a claw portion 52 protruding from the outer peripheral surface of the sub-valve body 3 and inserted into the window hole 51 with a clearance. Moreover, when the sub-valve body 3 moves in the opening direction relative to the main valve body 2 and the claw portion 52 engages with the opening direction edge of the window hole 51, the sub-valve body 3 does not move further in the opening direction relative to the main valve body 2.

[0020] The end face of the linear moving body 6 in the closing direction is formed as a convex spherical surface, and this convex surface is brought into contact with the end face of the sub-valve body 3 in the opening direction. The linkage mechanism 7 is constituted by a feed screw mechanism, and this feed mechanism is constituted by an external thread 71 connected to the output shaft 81 of the stepping motor 8 and a slider 72 that is screwed with the external thread 71 and is fixed against rotation. The slider 72 abuts against a diaphragm 61 that separates the arrangement portion of the linkage mechanism 7 from the valve chamber 13, and the linear moving body 6 is connected to this diaphragm 61.

[0021] As Figure 1 shown, while the main valve body 2 (more precisely, the plugging portion 23 of the main valve body 2) is seated on the valve seat 14, the sub-valve body 3 is seated on the sub-valve seat 25 of the main valve body 2 and plugs the bypass hole 24. At this time, the state is the fully closed state of the electric type fire control valve A, and thus the supply of gas to the stove burner B is stopped. When the linear moving body 6 moves in the opening direction from this fully closed state through the stepping motor 8 and by means of the linkage mechanism 7, the sub-valve body 3 follows the linear moving body 6 by the acting force of the second biasing mechanism 42 and moves in the opening direction. Until the movement of the sub-valve body 3 in the opening direction relative to the main valve body 2 is stopped by the stop mechanism 5, the movement of the main valve body 2 in the opening direction is blocked by the acting force of the second biasing mechanism 42. Therefore, it is maintained in the state where the main valve body 2 is seated on the valve seat 14, and moreover, the sub-valve body 3 separates from the sub-valve seat 25 and the bypass hole 24 is opened. Accordingly, the electric type fire control valve A becomes the minimum fire state where the fire of the burner B is at the minimum. After the movement of the sub-valve body 3 in the opening direction relative to the main valve body 2 is stopped by the stop mechanism 5, if the sub-valve body 3 is further moved in the opening direction, the main valve body 2 follows the sub-valve body 3 by the acting force of the first biasing mechanism 41 and moves in the opening direction. The main valve body 2 separates from the valve seat 14, and the fire of the burner B gradually increases.

[0022] Here, when the electric type fire control valve A of the present embodiment is in the fully closed state, the sub-valve body 3 is seated on the sub-valve seat 25 at the gasket 32 position. Therefore, different from the above-mentioned conventional example where the sub-valve seat 25 formed of a hard material of the main valve body 2 abuts against the portion formed of a hard material of the sub-valve body 3, it is possible to surely prevent poor sealing in the fully closed state.

[0023] In addition, the stepping motor 8 is periodically made to lose steps in the fully closed state for origin return. In the present embodiment, when performing origin return, the amount by which the gasket 32 of the sub-valve body 3 is compressed is the above-mentioned specified compression amount, as Figure 1As shown, the front end of the valve body 31 of the sub-valve body 3 abuts against the sub-valve seat 25. Accordingly, the origin position of the stepping motor 8 can be fixed without being affected by the uneven compression of the gasket 32, and the fire intensity can be accurately adjusted based on this origin position. In addition, when performing origin return, the blocking portion 23 of the main valve body 2 is also compressed, causing the flange portion 22a to abut against the valve seat 14.

[0024] As described above, the embodiments of the present invention have been described with reference to the accompanying drawings. However, the present invention is not limited thereto. For example, in the above-described embodiment, although the linkage mechanism 7 is constituted by a feed screw mechanism, it may be constituted by a member other than the feed screw mechanism, such as a rack and pinion mechanism or a cam mechanism.

Claims

1. An electric fire control valve, which is arranged on the gas supply path of a stove burner, The electric fire control valve includes: A main valve body, which is arranged in a valve chamber in a valve housing in such a way that it can move freely in a closing direction approaching a valve seat at one end in the valve chamber and an opening direction away from the valve seat; A sub-valve body, which is opposed to the main valve body in the opening direction; A first biasing mechanism, which biases the main valve body in the opening direction; A second biasing mechanism, which biases the sub-valve body in the opening direction relative to the main valve body with a force stronger than that of the first biasing mechanism; A stopper mechanism, which restricts the movement of the sub-valve body in the opening direction relative to the main valve body to a fixed position; A direct-acting body, which abuts against the sub-valve body from the opening direction; And A stepping motor, which drives the direct-acting body in the opening direction and the closing direction by means of a linkage mechanism, The main valve body has: a bypass hole for allowing gas to flow from the upstream side to the downstream side of the main valve body even in a state where the main valve body is seated on the valve seat, and a sub-valve seat on which the sub-valve body can be seated and which makes the bypass hole open, It is possible to switch to: a fully closed state in which the main valve body is seated on the valve seat and the sub-valve body is seated on the sub-valve seat, and is characterized in that, A gasket made of an elastic material opposed to the sub-valve seat is installed on the sub-valve body, The sub-valve body is seated on the sub-valve seat at the gasket position, The sub-valve body includes a valve body formed of a hard material, The valve body has: a hollow portion that is open at the front end of the valve body opposed to the sub-valve seat, The gasket is installed in the hollow portion in such a manner that the front end portion of the gasket opposed to the sub-valve seat protrudes from the front end of the valve body by a specified amount of compression, When the stepping motor loses steps and performs origin return in the fully closed state, the amount by which the gasket is compressed is the specified amount of compression, so that the front end of the valve body abuts against the sub-valve seat.

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