JP2005315221A - Exhaust gas pressure sensing type control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust pressure sensing type control valve capable of variously adjusting valve opening characteristics to simultaneously achieve various characteristics required for an exhaust system for an engine. <P>SOLUTION: A cover member 8 blocking a communication pipe 1 is rotatably attached to a rotating shaft 7 provided on a side of the communication pipe 1, and a coil spring 11 is fitted on the rotating shaft 7 and energizes the cover member 8 in a direction of the communication pipe 1, namely in a regular direction and a reverse direction of exhaust gas at one open end part 12 of the winding. Another open end part 13 of the winding of the coil spring 11 is fitted into a guide groove 6 formed on a bottom plate 5 of a bracket 2. The guide groove 6 is under a non-linear condition such as a polygonal line shape or a curved line shape, when the cover member 8 is closed according to exhaust gas flow amount, another end part 13 of the winding moves accompanying rotation of the coil spring 11, energizing force of the cover member 8 by the coil spring 11 is changed by regulating moving amount or moving rate to enable to variously adjust valve opening characteristics. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust pressure sensitive control valve that is attached to a communication pipe in a silencer of a vehicle and that opens and closes by exhaust gas from an engine.

It is known that noise is reduced by a resonance effect or an expansion effect by forming several compartments in a muffler of a vehicle and appropriately communicating or blocking them. When communicating or shutting off between the compartments, a communication pipe is inserted between the compartments, and an exhaust pressure sensitive control valve that opens and closes with the exhaust gas from the engine is attached to the opening end of the compartment. There is an exhaust pressure-sensitive control valve that controls opening and closing of the valve according to the rotation state. As such an exhaust pressure-sensitive control valve, for example, a lid member that opens and closes the open end of the communication pipe and a coil spring that biases the lid member in a direction opposite to the flow direction of the exhaust gas are provided on different axes. When the lid member is opened and closed by the exhaust gas, the end of the coil spring slides along the surface of the lid member, thereby changing the biasing force of the lid member by the coil spring and opening the valve with respect to the exhaust gas flow rate. There is one that adjusts the degree characteristic (for example, Patent Document 1).
JP 2001-90529 A

By the way, the exhaust system of a vehicle is required to reduce noise when the rotational speed of the engine is low and to reduce exhaust pressure when the rotational speed of the engine is high. In order to satisfy these requirements, for example, in an exhaust pressure sensitive control valve, when the engine speed is low, that is, when the exhaust gas flow rate is small, the valve opening is made as small as possible, and when the engine speed is high, That is, it is desirable to make the valve opening as large as possible when the exhaust gas flow rate is large. However, in the conventional exhaust pressure-sensitive control valve, the end of the coil spring that biases the valve lid member simply slides along the surface of the lid member. Although the degree characteristic can be changed, the change range of the valve opening characteristic is small, and it is not possible to sufficiently achieve low noise when the engine is low and low exhaust pressure when the engine is high. Further, since the conventional exhaust pressure-sensitive control valve is provided with a shaft for attaching the lid member and a shaft for attaching the coil spring, the structure is complicated and the cost is increased accordingly.
The present invention has been made paying attention to the above problems, and an object thereof is to provide an exhaust pressure sensitive control valve capable of freely setting a valve opening characteristic with respect to an exhaust flow rate. Is.

  In order to solve the above-mentioned problem, the exhaust pressure sensitive control valve of the present invention is a exhaust pressure sensitive control valve that is attached to a communication pipe in a silencer of a vehicle and opens and closes by the pressure of exhaust gas from an engine. A shaft provided on the side of the open end of the communication tube, a lid member rotatably attached to the shaft, and opening and closing the open end of the communication tube, and being engaged with the shaft, A spring that urges the exhaust gas in a direction opposite to the flow direction of the exhaust gas, one end of the spring abuts on a surface opposite to the exhaust gas receiving surface of the lid member, and the other end of the spring communicates The guide groove provided in the vicinity of the opening end of the tube is regulated, and the shape of the guide groove is non-linear. The non-linear shape described above is a line having at least one inflection point, specifically, a polygonal line shape in which line segments are connected by inflection points, or a curved shape in which the curvature changes continuously, Alternatively, a shape in which the two shapes are mixed may be used.

  Thus, according to the exhaust pressure-sensitive control valve of the present invention, the lid member that opens and closes the opening end of the communication pipe with respect to the shaft provided on the side of the opening end of the communication pipe in the silencer; A spring for urging the lid member in a direction opposite to the flow direction of the exhaust gas, and attaching one end of the spring to a surface opposite to the exhaust gas receiving surface of the lid member; By restricting the end portion with the guide groove and making the shape of the guide groove non-linear, it becomes possible to freely set the valve opening characteristic with respect to the exhaust flow rate to be non-linear.

Next, a first embodiment of the exhaust pressure sensitive control valve of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of the exhaust pressure sensitive control valve of the present embodiment, and FIG. 2 is a plan view of FIG. Reference numeral 1 in these drawings denotes a communication pipe that communicates between compartments in a silencer provided in an exhaust system of a vehicle, for example. A bracket 2 is attached to the open end of the communication pipe 1 to form a saucer-shaped valve seat 3 outside the open end and to attach a lid member that is the valve itself. The bracket 2 has two wall portions 4 erected toward the side of the opening end of the communication pipe 1. Further, a bottom plate 5 is provided below the wall portion 4, that is, in a direction opposite to the standing direction of the wall portion 4, and a guide for guiding an end portion of a coil spring to be described later is provided on the bottom plate 5. A groove 6 is formed. The shape of the guide groove 6 will be described in detail later.

  A rotating shaft 7 made of a round bar is inserted between the two wall portions 4 of the bracket 2. A lid member 8 as a valve itself for opening and closing the communication pipe 1 is rotatably attached to the rotating shaft 7. The lid member 8 closes the open end of the communication pipe 1 in the valve closed state and opens the open end of the communication pipe 1 in the valve open state. A portion of the lid member 8 facing the valve seat 3 of the bracket 2 is formed with a dish-like contact surface 9, and the communication tube 1 is reliably closed by the contact surface 9 and the valve seat 3. .

  A coil spring 11 is also fitted on the rotary shaft 7. Specifically, the wall portion 10 of the lid member 8 abuts on the inside of each wall portion 4 of the bracket 2, and the coil spring 11 is accommodated between the wall portions 10 of the lid member 8. The coil spring 11 itself is a torsion spring made of a normal elastic metal, and the two open end portions 12 and 13 of the winding protrude laterally from the winding. One open end 12 of the winding of the coil spring 11 is opposite to one surface of the lid member 8, specifically, the surface opposite to the surface that closes the communication pipe 1, in other words, opposite to the exhaust gas receiving surface. As a result, the lid member 8 is urged in the direction opposite to the flow direction of the exhaust gas. On the other hand, the other open end 13 of the winding of the coil spring 11 is fitted into a guide groove 6 formed in the bottom plate 5 of the bracket 2. Therefore, as shown in FIG. 3, the lid member 8 is urged in the direction opposite to the exhaust gas flow direction by one open end 12 of the coil spring 11 so that the open end of the communication pipe 1 is opened. Although it is closed, it rotates around the rotary shaft 7 as the flow rate of the exhaust gas increases, and the open end of the communication pipe 1 is opened. If there is no restriction, the other open end 13 of the winding of the coil spring 11 is free to move in the direction of the arrow in FIG.

  The guide groove 6 has a shape as shown in FIG. 4 in a plan view of FIG. In the present embodiment, a multi-stage broken line having a plurality of inflection points is formed in a so-called non-linear shape. The other end 13 of the winding of the coil spring 11 indicated by a solid line in the figure corresponds to the position where the lid member 8 closes the communication pipe in FIG. With the opening operation of the lid member 8 shown in FIG. 3, the other open end 13 of the winding of the coil spring 11 moves in the direction of the arrow in FIG. This is indicated by a broken arrow in the drawing of the guide groove 6 in FIG. For example, if the position of the other open end 13 of the coil spring 11 in the state where the lid member 8 closes the communication pipe is the fully closed position, the direction of the arrow in FIG. The guide groove 6 is once inclined at a large angle with respect to the movement direction of the other open end of the winding 11 and then inclined at a smaller angle to form a broken line as a whole. For example, when the abutment point of the guide groove having a different inclination angle, that is, the inflection point is an intermediate position, and the end point position of the guide groove having a small inclination angle is a fully open position, the other open end portion 13 of the winding of the coil spring 11 is As the lid member 8 is opened, the lid member 8 moves from the fully closed position to the intermediate position, and then moves to the fully opened position. The reverse occurs when the lid member 8 is closed. That is, the movement amount or movement rate from the fully closed position to the intermediate position is relatively small with respect to the original movement direction of the other open end 13 of the winding of the coil spring 11, and the movement from the intermediate position to the fully open position is relatively small. The quantity or transfer rate is relatively large.

  FIG. 5 shows the relative positional relationship between the lid member 8 and the communication tube 1 when the other open end 13 of the winding of the coil spring 11 is in the fully closed position of the guide groove 6. FIG. 6 shows a relative positional relationship between the lid member 8 and the communication pipe 1 when the other open end 13 of the winding of the coil spring 11 is at an intermediate position of the guide groove 6. FIG. 7 shows the relative positional relationship between the lid member 8 and the communication pipe 1 when the other open end 13 of the winding of the coil spring 11 is in the fully open position of the guide groove 6. For example, during the opening operation of the lid member 8, while the other open end 13 of the winding of the coil spring 11 moves from the fully closed position of the guide groove 6 to the intermediate position, the other opening of the winding of the coil spring 11 is opened. Since the moving amount or moving rate of the end portion 13 is small, the urging force of the coil spring 11 generated with the opening operation of the lid member 8 is large, and therefore the lid member 8 is not easily opened. On the other hand, during the opening operation of the lid member 8, while the other open end 13 of the winding of the coil spring 11 moves from the intermediate position of the guide groove 6 to the fully open position, the other winding of the coil spring 11 is moved. Since the moving amount or moving rate of the open end 13 is large, the urging force of the coil spring 11 generated with the opening operation of the lid member 8 is small, and the lid member 8 is easily opened.

  Since the torque for opening the lid member 8, so-called valve opening torque, is equal to the exhaust flow rate from the engine, the relationship between the exhaust flow rate and the valve opening is shown by the solid line in FIG. According to this valve opening characteristic, when the exhaust flow rate is small, that is, when the valve opening amount is small, the rate of increase of the valve opening with respect to the increase of the exhaust flow rate, that is, the valve opening speed is small, and when the exhaust flow rate is large, that is, the valve When the opening is large, the rate of increase of the valve opening with respect to the increase of the exhaust flow rate, that is, the valve opening speed is large. That is, when the engine rotational speed is low, the valve opening characteristic with respect to the exhaust flow rate is small and the valve is difficult to open, so the valve opening is small and a low noise effect is obtained. Further, when the engine speed is high, the valve opening characteristic with respect to the exhaust flow rate is large, and the valve is easily opened. Therefore, the valve opening is large and a low exhaust pressure effect is obtained.

  Thus, according to the exhaust pressure-sensitive control valve of the present embodiment, the open end 13 of the coil spring 11 that biases the lid member 8 that is the valve itself is guided by the guide groove 6, and the guide groove 6 is By making it non-linear, the valve opening characteristic with respect to the exhaust flow rate is made non-linear so that a plurality of the valve opening characteristics can be set with one valve, thereby simultaneously achieving various characteristics required for the exhaust system. be able to. Further, by making the guide groove 6 in a polygonal line shape, tuning and processing are easy.

  Further, in the exhaust pressure sensitive control valve of the present embodiment, when the lid member 8 is opened by the exhaust gas flow and the open end 13 of the coil spring 11 moves along the guide groove 6, the opening degree of the lid member 8 is increased. By setting the inflection point of the shape of the guide groove 6 so that the opening speed of the lid member 8 increases as it increases, the low noise effect when the engine speed is low and the low speed when the engine speed is high It is possible to achieve both the exhaust pressure effect.

Further, in the exhaust pressure sensitive control valve of the present embodiment, the lid member 8 is rotatably attached to one rotating shaft and the coil spring 11 is fitted, so that there is no extra constituent member and the configuration is simple. This is also advantageous in terms of cost.
The shape of the guide groove 6 is not limited to the above, and may be a broken line as shown in FIG. 9 in which three straight lines having different inclination angles are joined.

Next, a second embodiment of the exhaust pressure sensitive control valve of the present invention will be described with reference to the drawings.
The front view of the exhaust pressure sensitive control valve of the present embodiment is the same as that of FIG. 1 of the first embodiment, but the plan view appears as shown in FIG. In this embodiment, only the shape of the guide groove 6 is different, and other configurations are the same as those of the first embodiment. Further, the behavior of the end portion of the winding of the coil spring 11 when the lid member 8 is opened and closed is the same as that in FIG. 3 of the first embodiment. In addition, the code | symbol in a figure was used similarly to the said 1st Embodiment.

  The guide groove 6 has a shape as shown in FIG. 11 in a plan view of FIG. In this embodiment, it forms in the curve shape which consists of a parabola in which a curvature becomes small continuously as it distances from the edge part of the baseplate 5. As shown in FIG. As in the first embodiment, the movement direction of the other open end 13 of the winding of the coil spring 11 that moves in accordance with the opening operation of the lid member 8 is indicated by the broken arrow in the drawing of the guide groove 6 in FIG. For example, when the position of the other open end 13 of the winding of the coil spring 11 in the state where the lid member 8 closes the communication pipe is the fully closed position, the direction of the broken arrow in FIG. That is, the guide groove 6 is inclined at a large angle with respect to the moving direction of the other open end of the winding of the coil spring 11, and the inclination angle is gradually decreased. Has a curved shape consisting of a small parabola. For example, when the point where the parabola curvature is the largest is the intermediate position and the end position of the guide groove where the parabola curvature is small is the fully opened position, the other open end 13 of the winding of the coil spring 11 opens the lid member 8. As a result, it moves from the fully closed position to the intermediate position and then smoothly moves to the fully open position. The reverse occurs when the lid member 8 is closed. That is, the movement amount or movement rate from the fully closed position to the intermediate position is relatively small with respect to the original movement direction of the other open end 13 of the winding of the coil spring 11, and the movement from the intermediate position to the fully open position The quantity or transfer rate is relatively large.

  FIG. 12 shows the relative positional relationship between the lid member 8 and the communication tube 1 when the other open end 13 of the winding of the coil spring 11 is in the fully closed position of the guide groove 6. FIG. 13 shows the relative positional relationship between the lid member 8 and the communication pipe 1 when the other open end 13 of the winding of the coil spring 11 is in the middle position of the guide groove 6. FIG. 14 shows the relative positional relationship between the lid member 8 and the communication pipe 1 when the other open end 13 of the winding of the coil spring 11 is in the fully open position of the guide groove 6. For example, when the lid member 8 is opened, the other open end 13 of the winding of the coil spring 11 moves from the fully closed position of the guide groove 6 to the intermediate position while the other open of the winding of the coil spring 11 is opened. Since the moving amount or moving rate of the end portion 13 is small, the urging force of the coil spring 11 generated with the opening operation of the lid member 8 is large, and therefore the lid member 8 is not easily opened. On the other hand, during the opening operation of the lid member 8, while the other open end 13 of the winding of the coil spring 11 moves from the intermediate position of the guide groove 6 to the fully open position, the other winding of the coil spring 11 is moved. Since the moving amount or moving rate of the open end 13 is large, the biasing force of the coil spring 11 generated with the opening operation of the lid member 8 is small, and the lid member 8 is easily opened.

  Since the torque for opening the lid member 8, so-called valve opening torque, is equal to the exhaust flow rate from the engine, the relationship between the exhaust flow rate and the valve opening is shown by the solid line in FIG. According to this valve opening characteristic, when the exhaust flow rate is small, that is, when the valve opening amount is small, the rate of increase of the valve opening with respect to the increase of the exhaust flow rate, that is, the valve opening speed is small, and when the exhaust flow rate is large, that is, the valve When the opening is large, the rate of increase of the valve opening with respect to the increase of the exhaust flow rate, that is, the valve opening speed is large. That is, when the engine speed is low, the valve opening is small, and a low noise effect is obtained. Further, when the engine speed is high, the valve opening is large, and a low exhaust pressure effect is obtained.

  As described above, according to the exhaust pressure sensitive control valve of the present embodiment, in addition to the same effects as those of the first embodiment, the guide groove 6 has a curved shape so that the inflection points of the guide groove are continuous. Therefore, the valve opening characteristic with respect to the exhaust flow rate can be continuously changed, and there is an original effect that it can be set more optimally with respect to the first embodiment. There is a unique effect that the movement of the winding tip of the coil spring 11 is smooth.

The curved shape of the guide groove is not limited to a parabola, and may be various curves such as an exponential function curve, a sine curve, and an arc curve.
Further, the shape of the guide groove 6 is not limited to the above, and may be a combination of three circular arc curves as shown in FIG. 16, for example.
Further, instead of the coil spring 11, a leaf spring 14 may be used as shown in FIGS.

It is a front view which shows 1st Embodiment of the exhaust pressure sensitive control valve of this invention. It is a top view of the exhaust pressure sensitive control valve of FIG. It is explanatory drawing of an effect | action of the exhaust pressure sensitive control valve of FIG. It is a top view of the guide groove of the coil spring end part provided in the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. FIG. 2 is a valve opening characteristic diagram of the exhaust pressure sensitive control valve of FIG. 1. It is a top view which shows the other example of the guide groove of the coil spring edge part of the exhaust pressure sensitive control valve of this invention. It is a top view which shows 2nd Embodiment of the exhaust pressure sensitive control valve of this invention. It is a top view of the guide groove of the coil spring end part provided in the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. It is a perspective view which shows the effect | action of the exhaust pressure sensitive control valve of FIG. FIG. 11 is a valve opening characteristic diagram of the exhaust pressure sensitive control valve of FIG. 10. It is a top view which shows the further another example of the guide groove of the coil spring edge part of the exhaust pressure sensitive control valve of this invention. It is a perspective view which shows other embodiment of the exhaust pressure sensitive control valve of this invention. It is a perspective view which shows other embodiment of the exhaust pressure sensitive control valve of this invention.

Explanation of symbols

1 is a communication pipe 2 is a bracket 3 is a valve seat 4 is a wall portion 5 is a bottom plate 6 is a guide groove 7 is a rotating shaft 8 is a lid member 9 is a close contact surface 10 is a wall portion 11 is a coil spring 12, and 13 is an open end portion 14 Is a leaf spring

Claims (6)

  An exhaust pressure sensitive control valve that is attached to a communication pipe in a silencer of a vehicle and opens and closes by the pressure of exhaust gas from an engine, and a shaft provided on the side of the open end of the communication pipe, A cover member that is rotatably mounted and opens and closes the open end of the communication pipe; and a spring that is engaged with the shaft and biases the cover member in a direction opposite to the flow direction of the exhaust gas. One end portion of the spring is in contact with the surface opposite to the exhaust gas receiving surface of the lid member, and the other end portion of the spring is regulated by a guide groove provided in the vicinity of the opening end portion of the communication pipe. Exhaust pressure sensitive control valve characterized by non-linear groove shape.   2. The exhaust pressure sensitive control according to claim 1, wherein the guide groove has a guide shape in which the initial load of the spring decreases as the input applied to the spring increases as the lid member opens. valve   The exhaust pressure-sensitive control valve according to claim 1 or 2, wherein the guide groove has a multi-stage broken line shape.   The exhaust pressure-sensitive control valve according to claim 1 or 2, wherein the guide groove has a curved shape.   When the cover member is opened by the exhaust gas flow and the other end of the spring moves along the guide groove, the shape of the guide groove is such that the opening speed of the cover member increases as the opening degree of the cover member increases. The exhaust pressure-sensitive control valve according to any one of claims 1 to 4, wherein:   An exhaust pressure-sensitive valve that opens and closes according to the pressure of exhaust gas from an engine, wherein the valve opening per unit pressure increases as the exhaust gas pressure increases.

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