JP4255353B2 - Exhaust flow path control valve - Google Patents

Description

  The present invention relates to an exhaust passage control valve used when, for example, opening and closing a bypass passage provided in a silencer in an exhaust system of an engine such as an automobile.

  Conventionally, as described in, for example, Patent Document 1 below, a silencer in an exhaust system of an engine of an automobile or the like is provided with a bypass passage separately from a normal exhaust passage through which exhaust can be circulated at all times, and the bypass passage is opened and closed. By providing an exhaust flow control valve, the exhaust from the engine is silenced through the normal exhaust passage and then released to the atmosphere when the engine is rotating at low speed, and the exhaust flow is increased when the exhaust pressure is increased when the engine is rotating at high speed. It is known that the passage control valve is opened so that the exhaust gas also flows from the bypass passage to prevent a decrease in engine output due to an increase in exhaust pressure.

  As the exhaust flow control valve as described above, conventionally, as described in Patent Document 1, a butterfly valve that opens and closes by rotating the valve body around the shaft is often used. There is a problem that the manufacturing cost is increased because a bearing or the like that supports the shaft in a rotatable manner is necessary. Therefore, for example, as disclosed in Patent Documents 2 and 3 below, it has been proposed to use a spiral member as a low-cost valve body that does not require a bearing.

  For example, the exhaust flow control valve described in Patent Document 3 has a substantially cylindrical housing that circulates exhaust from the engine, a spiral valve body that opens and closes a passage in the housing, and the valve body is always closed. A coil spring of a torsion coil spring biased in a direction, and abutting and fixing an outer peripheral portion of the spiral valve body to a flange portion provided at a peripheral edge portion of the housing. A substantially semi-cylindrical valve spring holder for engaging and holding the portion is integrally fixed to the valve body.

  By attaching the exhaust flow path control valve configured as described above to, for example, the bypass passage in the silencer as described above, the rotational speed of the engine increases and the pressure in the silencer near the bypass passage becomes a predetermined value. When it rises above, the spiral valve body spreads in the direction of the spiral winding axis and the valve opens, and when the engine speed decreases and the pressure in the silencer drops below a predetermined value, the valve closes, Thereby, the bypass passage is opened and closed.

  However, the valve body may be gradually deformed by repeating the above opening and closing operations, and the valve closing function may be lowered.In particular, when the set load of the valve spring is increased to increase the valve opening set pressure. The pressure at the time of closing the valve body is increased by the valve spring, and deformation or the like is likely to occur. Therefore, in Patent Document 3, it is proposed that a valve closing stopper that contacts the surface of the spiral valve body opposite to the valve spring to prevent deformation of the valve body is attached to the inner surface of the housing. However, it is troublesome to provide such a dedicated valve closing stopper at a predetermined position with high accuracy, and there are problems such as an increase in the number of parts and assembly man-hours and an increase in manufacturing cost.

JP-A-6-221130 JP-A-11-287118 Japanese Patent Laid-Open No. 2001-207827

  The present invention has been proposed in view of the above-described conventional problems, and an exhaust passage that can satisfactorily prevent deformation of a valve body due to pressure at the time of valve closing without providing a valve closing stopper as described above. An object is to provide a control valve.

In order to achieve the above object, an exhaust passage control valve according to the present invention has the following configuration. That is, a valve spring comprising a substantially cylindrical housing through which exhaust from the engine circulates, a spiral valve body that opens and closes a flow passage in the housing, and a torsion coil spring that urges the valve body in a direction to always close the valve body And a substantially semi-cylindrical valve that engages and holds the coil portion of the valve spring while fixing the outer peripheral portion of the spiral valve body to a flange portion provided on the peripheral portion of the housing. In the exhaust flow control valve formed by integrally fixing the spring holder to the valve body, the valve spring holder is formed in the diameter direction of the spiral valve body so as to have a length substantially equal to the diameter of the valve body. It is characterized by that.

A substantially semi-cylindrical valve spring holder for engaging and holding the coil portion of the valve spring while fixing the outer peripheral portion of the spiral valve body to the flange portion provided on the peripheral portion of the housing as described above. In the diameter direction of the spiral valve body, the length of the valve body is approximately the same as the diameter of the valve body, so that when the valve is closed, the valve body is pressed to the opposite side of the valve spring and bent in the same direction. When such a force is repeatedly received, both end portions of the valve spring holder come into contact with the valve seat portion via the valve body, thereby preventing the valve body from being bent and deformed more than a predetermined amount. It becomes possible to improve durability and reliability.

  FIG. 1A is a front view showing an embodiment of an exhaust passage control valve according to the present invention, FIG. 1B is a side view thereof, and FIG. 2 is an AA enlarged sectional view in FIG. .

  The exhaust passage control valve of the present embodiment circulates exhaust from the engine by providing it in communication with a bypass passage provided in a silencer (not shown) in an exhaust system of an engine such as an automobile not shown in the figure. A substantially cylindrical housing 1, a spiral valve body 2 that opens and closes a passage 1a in the housing 1, and a valve spring 3 that includes a torsion coil spring that urges the valve body 2 in a normally closing direction. The outer peripheral portion of the spiral valve body 2 is fixed in contact with the flange portion 10 provided on the peripheral edge portion of the housing 1, and the coil portion 30 of the valve spring 3 is engaged and held. The valve spring holder 4 is integrally fixed to the valve body 2 by welding or the like.

  The housing 1 is formed in a cylindrical shape so as to be connected to an inner pipe or the like constituting a bypass flow path in the silencer, and a flange portion 10 that also serves as a valve seat portion of the valve body 2 is formed on one end side thereof. Is provided. In the present embodiment, as shown in FIG. 3, the valve body 2 is formed by combining a pair of spiral plates 21 and 22 into a double spiral shape, and semicircular central portions 21 a of both the spiral plates 21 and 22. The one in which one spiral valve body 2 is constructed by butt welding 22a at its semicircular strings 21b and 22b is used. The valve body 2 is formed by overlapping the overlapping portions of the spiral plates 21 and 22 on the outer peripheral portion thereof with the flange portion 10 of the housing 1 to form the flange portion 10 and folded pieces 10a formed at a plurality of locations around the flange portion 10. It is clamped and fixed in between.

  The valve spring 3 is a torsion coil spring comprising a coil portion 30 and a pair of arm portions 31 and 31 projecting from both ends thereof, and a substantially semi-cylindrical valve spring holder for engaging and holding the coil portion 30. 4 is integrally attached to the central portion of the valve body 2 by welding or the like. The coil portion 30 engaged with and held by the valve spring holder 4 is positioned and fixed between a pair of upright pieces 41 and 41 provided on the holder 4, and a pair of arm portions 31 and 31 extending from both ends of the coil portion 30. Are slidably inserted and held in a spring receiver 11 provided integrally with the flange portion 10 of the housing 1 through a through hole (not shown).

  The pair of arm portions 31 and 31 always tend to open in the opposite direction to the housing 1, and the reaction force causes the central portion of the valve body 2 to move toward the housing 1 via the coil portion 30 and the valve spring holder 4. As a result, the adjacent spiral plates 21 and 22 of the valve body 2 overlap each other in a close contact state and are kept in a normally closed state. When the exhaust pressure in the housing 1 rises to a predetermined level or more, the valve body 2 is pushed rightward in FIG. 1A against the valve spring 3, and the spiral plates 21 and 22 overlap each other. A gap is formed in the so-called valve open state.

  At that time, the coil portion 30 and the arm portions 31 and 31 of the valve spring 3 move in the same direction as the valve body 2 moves rightward in FIG. The bent portion 31a provided at the tip of each arm portion 31 comes into contact with the spring receiver 11 to prevent further movement. As a result, the degree of opening (opening amount) of the valve body 2 is restricted and the valve spring 3 is prevented from being detached. In particular, in the present embodiment, only the bent portion 31a is used for the valve body 2. The opening amount and the detachment of the valve spring 3 can be regulated, and the opening amount of the valve body 2 can be adjusted only by appropriately changing the position where the bent portion 31a is provided. Therefore, there is no trouble of separately providing a valve opening stopper or the like as described in Patent Document 3, and it is possible to prevent an increase in exhaust resistance.

And in the present invention, the substantially semi-cylindrical valve spring holder 4 in the diametrical direction of the valve body 2, made by forming a length of a diameter substantially equal to the valve body 2, particularly in the present embodiment As shown in FIGS. 1B and 2, both end portions 4 a in the axial direction of the substantially semi-cylindrical valve spring holder 4 are extended to the peripheral edge of the valve body 2. By configuring as described above, when the valve body 2 is closed by the elastic restoring force of the valve spring 3 from the opened state, both end portions 4a of the valve spring holder 4 are interposed via the peripheral portion of the valve body 2. By contacting the flange portion 10 that also serves as a valve seat portion of the valve body 2, the valve body 2 is prevented from being deformed by an impact or the like when the valve is closed. In particular, it is possible to satisfactorily prevent problems such as the central portion of the valve body 2 being bent inward of the housing 1 due to an impact when the valve is closed and the sealing performance is deteriorated.

  It should be noted that the both end portions 4a of the valve spring holder 4 may be in contact with the peripheral portion of the valve body 2 in the initial state when the valve body 2 is closed, or may have a slight clearance. In the case of the figure, both end portions 4a are provided with protrusions 42 such as protrusions protruding toward the valve body 2 as shown in FIG. 2, but both end portions 4a of the valve spring holder 4 are bent and formed. You may make it contact | abut or approach the valve body 2. FIG.

  Further, when a single valve body 2 is configured by combining a pair of spiral plates 21 and 22 in a double spiral shape as in the above embodiment, the spiral plates 21 and 22 are simply combined (superposed) as they are. When attached to the flange portion 10, as shown in FIGS. 4 (a) and 4 (b), a gap g is often generated between the peripheral portions of the spiral plates 21 and 22 and the flange portion 10 as shown in the figure, thereby causing pressure leakage. For example, if the peripheral portions of the spiral plates are pressed with a press or the like before or after the spiral plates 21 and 22 are combined, they are attached to the flange portion 10 as shown in FIG. As shown in (c), it can be assembled with almost no gap g as described above.

  Further, the valve body 2 is not limited to a combination of the pair of spiral plates 21 and 22 as described above in a double spiral shape, but only a single spiral plate as described in Patent Document 2, for example. The valve body which consists of can also be used.

  As described above, in the exhaust flow path control valve according to the present invention, the substantially semi-cylindrical valve spring holder 4 that engages and holds the coil portion 30 of the valve spring 3 is formed to have a length that covers substantially the entire length of the valve body 2 in the diameter direction. With such an extremely simple configuration, it is possible to satisfactorily prevent deformation or the like due to repetitive operation of the valve body 2, and it is possible to improve the reliability, stability, durability, etc. of this type of valve. Further, it is not necessary to separately provide a valve closing stopper or the like, and the configuration is simplified. For example, in the above-described embodiment, the exhaust flow path is constituted by four parts of the housing 1, the valve body 2, the valve spring 3, and the valve spring holder 4. It is also possible to configure a control valve. Therefore, the number of assembling steps and manufacturing costs can be reduced, and the size and weight can be reduced, so that it can be easily installed in a limited small space even when it is installed in an exhaust system silencer of an engine, for example. It becomes possible to improve the freedom of selection and the freedom of design.

(A) is a front view of the exhaust-flow-path control valve by this invention, (b) is the side view. The AA expanded sectional view in FIG.1 (b). (A) is a disassembled perspective view of a pair of spiral plate which comprises a valve body, (b) is sectional drawing of the state which combined both the spiral plates. (A) is a plan view of a part of the state in which the pair of spiral plates are simply stacked and assembled, (b) is a front view thereof, and (c) is one of the states in which the spiral plate is assembled after press forming. Front view of the part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 1a Passage 10 Flange part 10a Folding piece 11 Spring receiver 2 Valve body 21, 22 Spiral plate 3 Valve spring 30 Coil part 31 Arm part 31a Bending part 4 Valve spring holder 4a End part 41 Standing piece 42 Projection part

Claims (2)

A substantially cylindrical housing through which exhaust from the engine circulates, a spiral valve body that opens and closes a flow passage in the housing, and a valve spring comprising a torsion coil spring that urges the valve body in a normally closing direction. A substantially semi-cylindrical valve spring holder that holds and fixes the outer periphery of the spiral valve body in contact with a flange provided on the peripheral edge of the housing and engages and holds the coil portion of the valve spring In the exhaust flow path control valve integrally fixed to the valve body, the valve spring holder is formed in the diameter direction of the spiral valve body to have a length substantially equal to the diameter of the valve body. An exhaust passage control valve characterized by.   The exhaust passage control valve according to claim 1, wherein protrusions protruding toward the valve body are integrally provided at both ends of the valve spring holder.

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