JP4638375B2 - Exhaust control valve - Google Patents

Description

  In the present invention, the valve body facing the valve seat formed at the exhaust gas outlet of the exhaust pipe is urged in the valve closing direction by a spring, and the pressing force acting on the pressure receiving surface of the valve body by the exhaust gas flowing through the exhaust pipe is reduced. The present invention relates to an exhaust control valve in which a valve element is separated from a valve seat when the spring force of a spring is exceeded.

  An exhaust silencer provided with a control valve for controlling the flow rate of exhaust gas at the open end of a communication pipe provided in the silencer body of the engine or the open end of an exhaust gas discharge pipe extending outside from the silencer body is as follows. This is known from US Pat.

The control valve of the exhaust silencer is configured such that a bottomed cylindrical valve body is slidably fitted to a valve seat formed at the open end of a communication rod (or exhaust gas discharge pipe) in the silencer body. A compression coil spring disposed between the flange at the open end of the valve and the flange at the open end of the valve body biases the valve body in the direction of seating on the valve seat. When the valve body moves while compressing the coil spring due to an increase in exhaust gas pressure and moves away from the valve seat, the exhaust gas from the communication rod passes through the communication port formed on the outer peripheral surface of the valve body and enters the silencer body. To be discharged.
Japanese Patent No. 3342461

  By the way, when the coil spring of the control valve is constituted by a tension coil spring, if the exhaust gas pressure suddenly increases and the lift amount of the valve body of the control valve increases extremely, the coil spring is caught on the valve seat, resulting in malfunction. There is a possibility of waking up. In order to prevent this, the material strength of the coil spring may be set high, or a stopper may be provided to suppress the lift amount of the valve body. However, in the former case, there is a problem that the cost increases because the coil spring needs to have sufficient strength margin. In the latter case, a support member such as a stay is extended from the control valve to stop the coil spring. There is a problem that the number of parts increases and the structure becomes complicated.

  The present invention has been made in view of the above circumstances, and an object thereof is to regulate the upper limit value of the lift amount of the valve body of the exhaust control valve with a simple structure.

  In order to achieve the above object, according to the first aspect of the present invention, the valve body facing the valve seat formed at the exhaust gas outlet of the exhaust pipe is urged in the valve closing direction by a spring, and the exhaust pipe The exhaust control valve that separates the valve body from the valve seat when the pressing force acting on the pressure receiving surface of the valve body by the exhaust gas flowing through the valve exceeds the spring force of the spring, and a protective tube that covers the periphery of the exhaust pipe Is provided in parallel with the exhaust pipe, and an exhaust control valve is proposed in which a stopper for restricting the upper limit of the lift amount from the valve seat of the valve body is provided on the protective pipe.

  According to the invention described in claim 2, in addition to the configuration of claim 1, an exhaust control valve is proposed in which the protective pipe is a finisher that covers the exhaust gas outlet of the exhaust pipe. .

  According to the invention described in claim 3, in addition to the configuration of claim 1, the exhaust pipe is a communication pipe that communicates a plurality of sound deadening chambers defined inside the silencer body, and the protection pipe is An exhaust control valve characterized by being a silencer body is proposed.

  The first rear exhaust pipe 15 and the communication pipe 38 of the embodiment correspond to the exhaust pipe of the present invention, and the silencer body 26 and the finisher 51 of the embodiment correspond to the protective pipe of the present invention. The first and third silencing chambers 29 and 31 correspond to the silencing chamber of the present invention, and the coil spring 43 of the embodiment corresponds to the spring of the present invention.

  According to the first aspect of the present invention, the stopper that restricts the upper limit of the lift amount from the valve seat of the exhaust control valve is provided on the protective pipe that covers the periphery of the exhaust pipe in parallel with the axis, so that there is sufficient room for the spring. It is no longer necessary to provide a certain level of strength and an inexpensive spring can be used, but there is no need to provide a special support member to support the stopper on the exhaust control valve itself, reducing the number of parts and simplifying the structure Is possible.

  According to the second aspect of the present invention, the stopper for restricting the upper limit value of the lift amount of the control valve provided in the exhaust pipe is supported using the finisher that covers the exhaust gas outlet of the exhaust pipe. Is possible.

  Further, according to the configuration of claim 3, the silencer is provided with a stopper that regulates the upper limit value of the lift amount of the valve body of the control valve provided in the communication pipe that communicates with the plurality of silencer chambers divided inside the silencer body. It becomes possible to support using the main body.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a perspective view of an exhaust silencer, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a sectional view taken along line 5-5 of FIG. 3, and FIG. 6 is a sectional view taken along line 6-6 of FIG.

  As shown in FIGS. 1 and 2, an exhaust silencer M for an automobile includes a shell 21 having an approximately elliptical cross section and caulking portions 22 and 23 on the outer periphery so as to close the opening portions on the left and right ends of the shell 21. A muffler body 26 composed of a pair of fixed end plates 24 and 25 is provided. The interior of the silencer body 26 includes a first silencer chamber 29 and a second silencer chamber by a first partition plate 27 and a second partition plate 28 in which flanges 27a and 28a whose outer peripheral portions are bent are fixed to the inner surface of the shell 21 by press-fitting. 30 and a third silencing chamber 31.

  The downstream end of the front exhaust pipe 14 inserted into the silencer body 26 constitutes an exhaust gas introduction pipe 32, and the exhaust gas introduction pipe 32 passes through the second partition plate 28 and the first partition plate 27. To the first silencing chamber 29. The upstream end portion of the first rear exhaust pipe 15 inserted into the silencer body 26 constitutes a first exhaust gas exhaust pipe 33, and the first exhaust gas exhaust pipe 33 includes the first partition plate 27 and the second partition wall. It penetrates through the plate 28 and opens to the third silencing chamber 31. The upstream end portion of the second rear exhaust pipe 16 inserted into the silencer body 26 constitutes a second exhaust gas exhaust pipe 34, and the second exhaust gas exhaust pipe 34 penetrates the first partition plate 27. Open to the second silencing chamber 30. Both ends of the communication pipe 35 penetrating the first partition plate 27 and the second partition plate 28 open to the first silencing chamber 29 and the third silencing chamber 31. The communication pipe 35 facing the second silencing chamber 30 is formed with a number of punching holes 35a communicating with the inside and the outside. Finishers 51 and 52 for improving the appearance are provided at the rear ends of the first and second rear exhaust pipes 15 and 16 extending rearward through the rear end plate 25, respectively. Among them, the control valve 36 of the present embodiment is provided inside the finisher 51 of the first rear exhaust pipe 15.

  Next, the structure of the finisher 51 and the control valve 36 will be described with reference to FIGS.

  The finisher 51 arranged in parallel to the first rear exhaust pipe 15 is a funnel-shaped connecting portion 53 welded to the outer periphery of the first rear exhaust pipe 15 and a second end welded to the rear end of the connecting portion 53. 1 comprises a cylindrical portion 54 covering the outer periphery of the rear exhaust pipe 15 and a stopper 55 welded to the inner peripheral surface of the rear end of the cylindrical portion 54, and is provided at the outlet opening of the first rear exhaust pipe 15. The control valve 36 is covered with a finisher 51. The finisher 52 of the second rear exhaust pipe 16 is configured by supporting a cylindrical portion 54 with a pair of front and rear connecting portions 53, 53 as shown in FIG.

  The control valve 36 includes a generally disc-shaped valve body 41, a generally annular spring receiving member 42 welded to the outer periphery of the first rear exhaust pipe 15, and a slidable fit on the outer periphery of the first rear exhaust pipe 15. And a coil spring 43 to be joined. The valve body 41 is seated on an annular valve seat 15a formed at the downstream end of the first rear exhaust pipe 15, and has a size capable of closing the downstream end of the first rear exhaust pipe 15, from the outer periphery thereof. It is fixed to one end portion of the coil spring 43 by three spring fixing portions 41a that protrude at intervals of 120 °. A surface of the valve body 41 facing the downstream end of the first rear exhaust pipe 15 is a pressure receiving surface 41b that receives the pressure of the exhaust gas. The spring receiving member 42 is also fixed to the other end portion of the coil spring 43 by three spring fixing portions 42a that protrude from the outer periphery at 120 ° intervals.

  The stopper 55 provided on the finisher 51 includes a circular stopper main body 55a and three support arms 55b extending radially from the stopper main body 55a at 120 ° intervals. It is welded to the inner surface of the cylindrical portion 54. When the valve body 41 is seated on the valve seat 15a, a predetermined gap (for example, 6 mm) is formed between the valve body 41 and the stopper main body 55a.

  Next, the operation of the first embodiment having the above configuration will be described.

  In FIG. 2, the pressure applied to the pressure receiving surface 41b of the valve body 41 of the control valve 36 via the first rear exhaust pipe 15 is small during low load operation of the engine with low exhaust gas pressure. The valve is held at the valve closing position indicated by the solid line in FIG. 3 by the tensile force of 43, and communication between the first rear exhaust pipe 15 and the atmosphere is prevented. As a result, the exhaust gas from the front exhaust pipe 14 flows into the exhaust gas introduction pipe 32, the first silencing chamber 29, the punching holes 35a of the communication pipe 35, the second silencing chamber 30, the second exhaust gas exhaust pipe 34, and the second exhaust gas. It is discharged to the atmosphere through the rear exhaust pipe 16. As described above, the valve element 41 of the control valve 36 is held in the closed position during low load operation of the engine, so that the exhaust noise distribution effect in the exhaust silencer M is increased, thereby enhancing the exhaust silencing effect. Engine exhaust noise is reduced.

  When the engine operating state shifts from the low load operation to the high load operation, the pressure of the exhaust gas applied to the pressure receiving surface 41b of the valve body 41 of the control valve 36 increases, so that the valve body 41 resists the tensile force of the coil spring 43. 3 moves to a position indicated by a chain line in FIG. 3, and a clearance is generated between the first rear exhaust pipe 15 and the valve seat 15a, and the control valve 36 is opened. As a result, most of the exhaust gas from the front exhaust pipe 14 is the exhaust gas introduction pipe 32, the first silencing chamber 29, the communication pipe 35, the third silencing chamber 31, the first exhaust gas exhaust pipe 33, and the first rear exhaust. A part of the exhaust gas from the front exhaust pipe 14 is exhausted to the atmosphere through the pipe 15 and the control valve 36, and the exhaust gas introduction pipe 32, the first silencing chamber 29, the punching holes 35a of the communication pipe 35, the second silencing. It is discharged to the atmosphere through the chamber 30, the second exhaust gas discharge pipe 34 and the second rear exhaust pipe 16. Since the amount of movement of the valve element 41, that is, the opening area of the control valve 36 increases as the exhaust gas pressure increases, the flow resistance of the exhaust gas in the exhaust silencer M is reduced during high-load operation of the engine. The amount of engine output reduction can be minimized.

  As described above, when the engine load increases, the flow rate of the exhaust gas that passes through the control valve 36 increases. Therefore, the target ratio of the exhaust sound silencing effect and the engine output reduction suppressing effect is automatically set according to the engine load change. Thus, the exhaust silencer M can be made to exhibit optimum performance in accordance with changes in engine load.

  Further, the control valve 36 can be constituted by four members, that is, the first rear exhaust pipe 15, the valve body 41, the spring receiving member 42 and the coil spring 43, and originally for exhausting exhaust gas from the silencer body 26. Since the first rear exhaust pipe 15 is used as the attachment portion of the spring receiving member 42 and the valve seat 15a, the control valve 36 can be reduced in size, weight, and cost.

  Further, by using the tension coil spring 43, it is possible to replace the conventional bottomed cylindrical valve body with a simple plate-like valve body 41, and the control valve 36 is reduced in weight and has a small axial dimension. It can contribute to the conversion. In particular, the weight of the valve body 41 is reduced and the inertia is reduced, so that the valve body 41 can easily follow the pressure change of the exhaust gas, and the open / close response of the control valve 36 is improved. In addition, when the valve body is separated from the valve seat 15a, the coil spring 43 fitted to the outer periphery of the first rear exhaust pipe 15 serves as a guide, so that the position of the valve body 41 is regulated without providing any special guide means. It is possible to further reduce the weight by eliminating the guide means.

  By the way, when the exhaust gas pressure suddenly increases and the lift amount of the valve body 41 of the control valve 36 increases extremely, the coil spring 43 may be caught by the valve seat 15a. However, in the present embodiment, since the stopper 55 provided on the finisher 51 faces the valve body 41 via a predetermined gap, the valve body 41 contacts the stopper 55 and the upper limit value of the lift amount is regulated. Therefore, the lift amount is surely prevented from being excessively increased.

  As a result, an inexpensive coil spring 43 having a low material strength can be used. In addition, since the stopper 55 is supported by using the finisher 51 as a protective pipe arranged in parallel with the first rear exhaust pipe 15, the stopper support member such as a stay is extended from the control valve 36 to support the stopper 55. There is no need, and the number of parts can be reduced and the structure can be simplified.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the second embodiment, instead of the stopper 55 of the first embodiment, a metal net 56 fitted to the opening end of the cylindrical portion 54 of the finisher 51 is used as a stopper. Also according to the second embodiment, it is possible to achieve the same effect as that of the first embodiment.

  FIGS. 8 and 9 show a third embodiment of the present invention. FIG. 8 corresponds to FIG. 2, and FIG. 9 is an enlarged view of part 9 of FIG.

  In the first and second embodiments described above, the control valve 36 is provided in one finisher 51. In the third embodiment, the control valve 36 is provided in the silencer body 26. . The structure of the control valve 36 itself is the same as in the first and second embodiments.

  As shown in FIG. 8, a communication pipe 38 that passes through the first partition plate 27 and the second partition plate 28 and opens at both ends to the first silencer chamber 29 and the third silencer chamber 31 is provided inside the silencer body 26. Be placed. The communication pipe 38 is the same as the communication pipe 35 (see FIG. 2) of the first embodiment. A control valve 36 having the same structure as the control valve 36 of the first and second embodiments is provided at the end of the communication pipe 38 protruding into the third silencing chamber 31, and the valve body of the control valve 36 A stopper 24a that faces the front end plate 24 with a predetermined gap is formed integrally when the front end plate 24 is press-molded.

  According to the third embodiment, the pressure applied to the pressure receiving surface 41b of the valve body 41 of the control valve 36 from the first silencing chamber 29 via the communication pipe 38 during low load operation of the engine with low exhaust gas pressure. Therefore, the valve element 41 is held at the valve-closed position shown by the solid line in FIG. 9 by the tensile force of the coil spring 43, and the communication between the first silencing chamber 29 and the third silencing chamber 31 by the communication pipe 38 is prevented. . As a result, the exhaust gas from the front exhaust pipe 14 flows into the exhaust gas introduction pipe 32, the first silencing chamber 29, the punching holes 38b of the communication pipe 38, the second silencing chamber 30, the second exhaust gas exhaust pipe 34, and the second exhaust gas. It is discharged to the atmosphere through the rear exhaust pipe 16. As described above, since the valve element 41 is held in the closed position during the low load operation of the engine, the exhaust resistance of the exhaust gas in the exhaust silencer M is increased, so that the exhaust silence effect is enhanced and the exhaust noise of the engine is increased. Is reduced.

  When the engine operating state shifts from the low load operation to the high load operation, the pressure of the exhaust gas applied to the pressure receiving surface 41b of the valve body 41 of the control valve 36 increases, so that the valve body 41 resists the tensile force of the coil spring 43. 9 moves to a position indicated by a chain line in FIG. 9, a gap is generated between the valve seat 38 a of the communication pipe 38, and the first silencing chamber 29 and the third silencing chamber 31 communicate with each other via the communication pipe 38. To do. Since the amount of movement of the valve element 41, that is, the opening area of the control valve 36 increases as the exhaust gas pressure increases, the flow resistance of the exhaust gas in the exhaust silencer M is reduced during high-load operation of the engine. The amount of engine output reduction can be minimized.

  When the exhaust gas pressure increases and the lift amount of the valve body 41 of the control valve 36 increases, the valve body 41 comes into contact with the stopper 24a provided integrally with the front end plate 24, and the upper limit value of the lift amount is ensured. Be regulated. As a result, an inexpensive coil spring 43 with low material strength can be used, and the stopper 24a can be provided by using the end plate 24 of the silencer body 26 as a protective tube arranged in parallel with the communication tube 38 in the axial direction. Since it is formed, the number of parts of the control valve 36 can be reduced and the structure can be simplified.

  Other functions and effects of the third embodiment are the same as the functions and effects of the first embodiment described above.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.

The perspective view of the exhaust silencer concerning a 1st embodiment 2-2 line enlarged sectional view of FIG. Part 3 enlarged view of FIG. Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG. The figure corresponding to the said FIG. 3 based on 2nd Embodiment. The figure corresponding to the said FIG. 2 based on 3rd Embodiment 9 enlarged view of FIG.

Explanation of symbols

15 First rear exhaust pipe (exhaust pipe)
15a Valve seat 24a Stopper 26 Silencer body (protection tube)
29 The first silence room (silence room)
31 3rd muffler room (muffler room)
38 Communication pipe (exhaust pipe)
38a Valve seat 41 Valve body 41b Pressure receiving surface 43 Coil spring (spring)
51 Finisher (protection tube)
55 Stopper 56 Metal mesh (stopper)

Claims (3)

The valve body (41) facing the valve seat (15a, 38a) formed at the exhaust gas outlet of the exhaust pipe (15, 38) is urged in the valve closing direction by the spring (43), and the exhaust pipe (15, 38) is urged. ) When the pressing force acting on the pressure receiving surface (41b) of the valve body (41) by the exhaust gas flowing through the exhaust gas exceeds the elastic force of the spring (43), the valve body (41) becomes the valve seat (15a, 38a). An exhaust control valve separated from
A protective pipe (26, 51) covering the periphery of the exhaust pipe (15, 38) is arranged in parallel to the exhaust pipe (15, 38), and the lift amount is adjusted from the valve seat (15a, 38a) of the valve body (41). An exhaust control valve comprising a protective pipe (26, 51) provided with a stopper (55, 56, 24a) for regulating an upper limit value.   The exhaust control valve according to claim 1, characterized in that the protective pipe is a finisher (51) covering an exhaust gas outlet of the exhaust pipe (15). The exhaust pipe is a communication pipe (38) for communicating a plurality of silencer chambers (29, 31) defined inside the silencer body (26), and the protective pipe is a silencer body (26). The exhaust control valve according to claim 1.

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