JP3247621B2 - Muffler device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler device used in an internal combustion engine, for example, capable of switching between a low noise mode and a high output mode.

[0002]

2. Description of the Related Art A muffler device mounted on an engine (internal combustion engine) used in a vehicle such as an automobile has a function capable of achieving both quietness in a low engine speed region and high output in a high engine speed region. There is.

A muffler device capable of achieving both quietness in a low engine speed region and high output in a high engine speed region has a relatively narrow exhaust gas flow path and a high exhaust resistance in a low engine speed region. A low-noise mode that lowers the exhaust noise, and a high output that increases the output of the engine by reducing exhaust loss by increasing the exhaust gas flow path and reducing exhaust resistance in the high engine speed range. It has a function that can switch between modes.

There are various types of known muffler devices having the above-described functions, such as a muffler device 101 illustrated in FIG.
There is known a muffler device 151 as exemplified in FIG. A conventional first muffler device 101 illustrated in FIG. 5 includes a muffler main body 102, a control unit 103, and the like.

[0005] The muffler main body 102 includes partition walls 110 and 11.
1, the first chamber 112, the second chamber 113, and the third chamber 114
And an inlet pipe 115 and an outlet pipe 117 are provided, and a bypass pipe 119 is provided in a part of the outside. The inlet pipe 115 is connected to the first chamber 1 from outside the muffler body 102.
One end 115 a is opened to the third chamber 114 through the second chamber 113 and the second chamber 113, and a communication hole 116 for ventilation is provided so as to face the second chamber 113. The outlet pipe 117 has one end 117a open to the first chamber 112, penetrates the second chamber 113 and the third chamber 114, and the other end 117b opens outside the muffler main body 102. The bypass pipe 119 is provided with an opening / closing valve 104 therein, and is opened to the first chamber 112 and the third chamber 114 so that the exhaust gas can flow therethrough.

A communication pipe 118 is provided between the inlet pipe 115 and the outlet pipe 117. The communication pipe 118 penetrates a part of the partition 110 and communicates the first chamber 112 and the second chamber 113.

The control unit 103 includes a negative pressure pipe 122 connected to an intake manifold 121 of the engine 120 and the like.
And a check on-off valve 123, a negative pressure tank 124, a solenoid valve 125, an actuator 126, and the like, and are connected linearly via a pipe 127 in the above-described order. A pipe 129 capable of supplying air is connected to the solenoid valve 125, and a diaphragm or the like is provided inside the actuator 126, and one end of a cable 128 is connected to the actuator 126.

The other end of the cable 128 is connected to an on-off valve 104 provided in a bypass pipe 119, so that the on-off valve 104 is rotatable by an actuator 126 in the direction of arrow Y in FIG. ing.

The on-off valve 104 changes the flow path of the exhaust gas in the bypass pipe 119 by rotating in the direction of arrow Y, and switches between a low noise mode and a high output mode.

In the conventional first muffler device 101 configured as described above, since the solenoid valve 125 and the like are used, the operation of the on-off valve 104 with high accuracy can be expected in the target engine operating range. Engine 120
Is stored in a negative pressure tank 124, and an actuator 126 is operated by the negative pressure in the negative pressure tank 124,
Due to the structure of rotating the mode switching on-off valve 104 provided on the muffler main body 102, a negative pressure tank 124 for securing a negative pressure, a check valve 123, etc., are provided between the engine 120 and the muffler device 101. Such devices must be provided, and a considerable occupied space is required. Therefore, it tends to be large. In particular, since a large amount of intake negative pressure cannot be secured at one time, a negative pressure tank 124 is required, and a check valve 123 and the like are also required to operate the negative pressure tank 124, which complicates the structure. Moreover, when the engine 120 is mounted at the front of the vehicle body and the muffler device 101 is installed at the rear of the vehicle body, it is necessary to provide the negative pressure pipe 122 from the front to the rear of the vehicle body. It may be a factor that restricts the installation of other devices to be performed.

Therefore, as exemplified in FIG. 6, a muffler device 151 that enables mode switching without using a negative pressure tank is used. A second conventional muffler device 151 illustrated in FIG. 6 includes a muffler main body 152, an on-off valve 154, and the like.

The muffler main body 152 includes partition walls 160 and 16.
1, the first chamber 162, the second chamber 163, and the third chamber 164
And an inlet pipe 165 and an outlet pipe 167 are provided. The inlet pipe 165 is connected to the first chamber 162 from outside the muffler body 152.
And one end 165a penetrating through the second chamber 163 and the third chamber 16
4 and a communication hole 166 for ventilation is provided so as to face the second chamber 163. Outlet pipe 1
67, the one end 167a is open to the first chamber 162 and the second end
While penetrating the chamber 163 and the third chamber 164, the other end 1
67 b is open to the outside of the muffler main body 152.

A first communication pipe 168 and a second communication pipe 169 are provided between the inlet pipe 165 and the outlet pipe 167. The first
The communication pipe 168 is provided on the inlet pipe 165 side, and penetrates a part of the partition wall 160 to form the first chamber 1.
62 and the second chamber 163 communicate with each other. The second communication pipe 169 is provided on the outlet pipe 167 side, has an enlarged surface 169c whose diameter increases as one end 169a approaches the tip, opens to the first chamber 162, and has partitions 160, 161. And the other end 169 b opens to the third chamber 164, and the first chamber 16
2 and the third chamber 164 are communicated.

The on-off valve 154 is formed in a shape capable of contacting an enlarged surface 169c provided at one end 169a of the second communication pipe 169, and opens and closes with the center line O of the second communication pipe 169. The first chamber 1 of the second communication pipe 169 is arranged so that the center line of the valve 154 is on the same line.
It is provided at the tip of one end 169a on the 62 side. Further, a valve seat 196 is provided on the contact surface 195 of the on-off valve 154 which contacts the enlarged surface 169c of the second communication pipe 169.
Is provided.

The on-off valve 154 can be opened and closed around a rotating shaft 197, and is normally urged in a closing direction by a return spring (not shown) or the like. The conventional second muffler device 151 configured as described above resists the elastic force of the spring when the pressure of the exhaust gas discharged from the engine increases, that is, when the engine is operated in a high rotation range. The opening / closing valve 154 opens in the direction of arrow F in FIG. 6 to shift to the high-power mode by widening the flow path of the exhaust gas. Therefore, the structure is simple and the size can be reduced. 154 is directly related to the exhaust pressure itself,
In order to move in response, it is difficult to perform a predetermined opening / closing operation in a target predetermined engine operating range, and the mode switching of the muffler device 151 tends to be delayed.

[0016]

As described above, in the conventional first muffler device 101 (FIG. 5), accurate operation of the on-off valve 104 can be expected in a target engine operating range. And a negative pressure tank 124 are required, so that the size of the apparatus is increased and the number of parts tends to increase.

The above-mentioned conventional second muffler device 151
When the structure is simplified as shown in FIG. 6 to reduce the size of the apparatus, the on-off valve 154 moves directly and in response to the exhaust pressure itself, so that the on-off valve 154 can be accurately adjusted in the target engine operation region. There is a tendency that it is difficult to operate well and that high-precision mode switching becomes difficult.

As described above, the conventionally used muffler device has a drawback that switching of the mode with high accuracy and downsizing of the device are not compatible in a target engine operating range. Accordingly, an object of the present invention is to provide a muffler device that is small and that can switch modes with high accuracy in a target engine operating range.

[0019]

According to a first aspect of the present invention, there is provided a muffler device according to the first aspect of the present invention, comprising: a muffler body divided into a plurality of chambers by a partition wall; A communication unit for communicating the partitioned chambers with each other;
An on-off valve for opening and closing the communicating portion, an actuator provided on the muffler main body and operated by the pressure of the exhaust gas of the engine to open and close the on-off valve, and a pressure of the exhaust gas for operating the actuator according to the operation of the engine. And a control means for controlling the muffler device.
You.

In the present invention, the on- off valve has a valve body which can be brought into contact with and separated from the communication portion provided in the muffler main body, and a shaft part extending from the valve body in a direction penetrating an outer wall of the muffler main body. And the casing, wherein the actuator is joined to an outer surface of the muffler body,
A first space in which the pressure of the exhaust gas is applied to one side surface of the diaphragm, and the pressure or the atmospheric pressure of the exhaust gas is applied to the other side surface of the diaphragm. A second space is formed, a shaft of the valve body is connected to the diaphragm, and the on-off valve opens and closes according to the pressure of the exhaust gas or the introduction of atmospheric pressure.

As a result of taking the above-described measures, the following operation occurs. In the muffler device according to the first aspect, the actuator can be driven by using the pressure of the exhaust gas passing through the muffler device to open and close the on-off valve, so that a negative pressure pipe is provided from the engine to the muffler device. Without this, the on-off valve can be operated. Moreover, unlike using intake negative pressure, a large amount of exhaust gas can be used to open and close the on-off valve, so there is no need for a negative pressure tank that occupies a large amount of space, and the muffler device is compact. And the number of parts is small.

In addition, since the actuator is driven to open and close the on-off valve in accordance with the engine operating state, accurate operation of the on-off valve in the target engine operating range is expected.

In the present invention, a mechanism such as an actuator that opens and closes the on-off valve using the pressure of the exhaust gas is integrated around the muffler body, so that the muffler device can be further downsized. In addition, since the joining of the casing containing the diaphragm to the muffler body also serves as a seal for the shaft connecting the diaphragm and the valve body, a structure for slidably sealing the shaft is not required. Also, since the muffler device is reduced in size and the number of parts is reduced, the size and the structure are simplified.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the muffler device 1 includes a muffler main body 2, an actuator 3, an on-off valve 4, and the like.

The muffler main body 2 is divided into a first chamber 12 as a plurality of chambers and a second chamber 12 by partitions 10 and 11 as partition walls.
It is partitioned into a chamber 13 and a third chamber 14, and is provided with an inlet pipe 15, an outlet pipe 17, and the like.
The inlet pipe 15 is connected to the first
One end 15a penetrating through the chamber 12 and the second chamber 13 is connected to the third chamber 1
4 and a communication hole 16 for ventilation is provided so as to face the second chamber 13. An outlet pipe 17 provided substantially parallel to the inlet pipe 15 has one end 17.
a opens into the first chamber 12 and the second chamber 13 and the third chamber 14
And the other end 17b is open to the outside of the muffler main body 2.

A first communication pipe 18 and a second communication pipe 19 are provided between the inlet pipe 15 and the outlet pipe 17. The first communication pipe 18 is provided on the inlet pipe 15 side substantially in parallel with the inlet pipe 15, and penetrates a part of the partition wall 10 to communicate the first chamber 12 and the second chamber 13. . The second communication pipe 19 is provided on the outlet pipe 17 side substantially in parallel with the outlet pipe 17, one end 19 a is open to the first chamber 12, and the partitions 10, 11 are provided.
And the other end 19b is open to the third chamber 14 to communicate the first chamber 12 and the third chamber 14.

The communication hole 16, the first communication pipe 18, and the second communication pipe 19 constitute a communication portion described in this specification. The on-off valve 4 is connected to one end 19 a of the second communication pipe 19 so as to be detachable from the one end 19 a of the second communication pipe 19. And a shaft portion 37 extending in the direction.

The valve body 47 is connected to the second communication pipe 1.
9 has a substantially flat contact surface 45 that is in contact with one end 19a of the pipe 9 without any gap and exhibits sealing properties, and is formed to be larger than the outer diameter of the second communication pipe 19.

The shaft portion 37 is supported by the bearing member 25 of the actuator 3 so that the center line of the valve body 47 and the center line of the second communication pipe 19 are substantially parallel. As described later, the casing 2 of the actuator 3
Since the members 3 and 30 are joined to the muffler main body 2 so as to be airtight, there is no need to slidably seal between the shaft portion 37 and the bearing member 25.

Further, as shown in FIG.
One of the one end 19a of the valve body 9 and the contact surface 45 of the valve body 47 is formed of a mesh member having a wire mesh or the like in order to improve the sealing property between the one end 19a and the contact surface 45. A valve seat 46 may be provided.

The actuator 3 has a heat radiating section 20 and an operating section 21. The heat radiating section 20 includes a first casing 2 having a heat radiating fin 22 which is an example of a heat radiating means.
3 is integrally joined to the outer surface of the muffler main body 2 via a bearing member 25 supporting the shaft portion 37 so as to be airtight. The first casing 23 is provided with the heat radiating section 2.
0, and has a throttle gap 24 between the shaft portion 37 and the joint portion with the operating portion 21 so as to narrow the flow path of the exhaust gas. The bearing member 25 is also provided with an orifice 27 sufficiently spaced from the bearing 26 supporting the shaft 37 so as to narrow the flow path of the exhaust gas.

The operating portion 21 has a second casing 30 joined to the first casing 23 so as to be airtight, and a second casing 30 joined to the second casing 30 so as to be airtight and a second casing 30. Actuator 2 with casing 30
A third casing 31 forming an outer shell of the first casing;
A diaphragm 32 is provided between the casing 30 and the third casing 31 and divides the internal space of the operating part 21 into two parts.

The diaphragm 32 is sandwiched between a first pressure receiving member 33 and a second pressure receiving member 34, which are formed in a substantially flat plate shape.
Is divided into a space 35 and a second space 36. The other end 37b of the shaft portion 37 is connected to a substantially central portion of the pressure receiving members 33 and 34 and the diaphragm 32.

A spring 38 is provided between the second pressure receiving member 34 and the third casing 31 so that the pressure in the first space 35 and the pressure in the second space 36 are reduced. Are equal to each other, the valve element 47
Is kept in contact with one end 19 a of the second communication pipe 19.

In the case of the illustrated example, in order to cut off the heat transmission from the muffler main body 2 to the diaphragm 32, between the first casing 23 and the bearing member 25 and between the bearing member 25 and the muffler main body 2. Insulating materials 28 and 29 are provided as an example of the heat insulating means.
29 need not always be provided. In addition, the heat insulating material 2
8 and 29 may or may not be used in combination with the radiation fins 22.

A hole 39 is formed in a part of the first casing 23.
Is provided, and a hole 40 is also provided in a part of the third casing 31. One ends 41a, 42a of pipe-shaped pipes 41, 42 are connected to holes 39, 40 provided in the members 23, 31, respectively. Further, as shown in FIG. 1, the other ends 41b, 42 of the pipes 41, 42 are provided.
The switching valve 43 is connected to b. As the switching valve 43, for example, a solenoid valve or the like is used, and a pipe 44 communicating with the atmosphere is connected, so that the exhaust gas is discharged from the pipe 41 to the pipe 42 or the pipe 42 to the pipe 44.
It is possible to switch to flow to.

Reference numeral 48 in FIG. 1 denotes a control arithmetic unit which is an example of a control means. The control arithmetic unit is connected to a throttle opening sensor 49 and an engine speed sensor 50 and operates in accordance with the throttle opening and the engine speed. It has a function of controlling the switching valve 43. The control arithmetic device 48 may be configured by adding a function to an existing device such as an ECU (Engine Control Unit), or may be configured using an arithmetic device having a dedicated microprocessor or the like. May be.

The muffler device 1 configured as described above,
According to the command output from the control arithmetic unit 48, the flow of the exhaust gas in the pipes 41, 42 and 44 is changed by using the switching valve 43 to change the space 3 of the actuator 3
By controlling the pressure inside the muffler main body 2, the diaphragm 32 and the on-off valve 4 are moved to a position indicated by a solid line and a position indicated by a two-dot chain line Q1 in FIG. Change the flow path.

The timing of switching between the low noise mode and the high output mode by changing the flow path of the exhaust gas in the muffler body 2 is based on the engine speed and the throttle opening. As shown in FIG.
1 or more and less than R and throttle opening fully open (100%)
In the case where the engine speed is equal to or more than the first predetermined value S1 or the engine speed is equal to or more than the predetermined value R and the throttle opening is equal to or more than the second predetermined value S2 in the vicinity of the idle load, that is, as indicated by hatching in FIG. The high output mode is set in the selected region, and when the throttle opening is less than the second predetermined value S2 or when the engine speed is less than the predetermined value R and the throttle opening is equal to or more than the second predetermined value S2, the first predetermined When the value is less than the value S1 or less than the engine speed R1, the low noise mode is set.

Next, the operation of the muffler device 1 of the above embodiment will be described. First, for example, when the engine is idling and the vehicle is stopped, the throttle opening sensor 49 and the engine speed sensor 50 indicate that the throttle opening is near the predetermined value S2 and the engine speed is the predetermined value R. 4 is detected and a signal corresponding to this value is detected by the control arithmetic unit 48.
Send to In this case, the control arithmetic unit 48 sets the flow path of the exhaust gas to the pipe 41 as indicated by an arrow U2 shown in FIG.
The switching valve 43 is controlled so as to be formed from the pipe 42 to the pipe 42.

The bearing member 2 of the actuator 3
From the orifice 27 provided in the first casing 2
The exhaust gas that has flowed into the space inside the third casing 31 flows through the pipes 41 and 42 from the hole 39 of the first casing 23 as shown by the arrow U2, and from the hole 40 of the third casing 31 to the second space 36. Inflow. Since the orifice 27 and the throttle gap 24 of the bearing member 25 are formed so as to narrow the flow path of the exhaust gas, the exhaust gas flows through the orifice 27 and the throttle gap 24 as shown by a two-dot chain line U1 in FIG. After the flow rate is restricted and the exhaust gas passes through the orifice 27 and the throttle gap 24, the exhaust gas expands to reduce the flow velocity and reduce the temperature of the exhaust gas, so that the heat of the exhaust gas acting on the diaphragm 32 is reduced. Shock can be reduced. Further, the flow of the exhaust gas flowing through the orifice 27 and the throttle gap 24 changes its course in the shape of a crank, and when the exhaust gas passes through the first casing 23, the flow velocity decreases and the exhaust gas flows in the vicinity of the radiation fins 22. Therefore, the heat of the exhaust gas can be released from the radiation fins 22 to the outside of the muffler device 1. Therefore, the heat of the exhaust gas acting on the diaphragm 32 can be further reduced. For example, as shown in FIGS. 1 and 2, the orifice 27, the throttle gap 24, the radiation fins 22, and the heat insulating material 2
In the case where 8, 29, etc. are provided, the temperature of the exhaust gas acting on the diaphragm 32 can be lowered to the heat-resistant temperature (for example, 200 ° C.) of the diaphragm 32 or lower.

As described above, the space 3 of the actuator 3
2A, the pressure in the valves 5 and 36 becomes substantially equal, and the valve body 47 of the on-off valve 4 abuts on one end 19a of the second communication pipe 19 as shown in FIG. Becomes Since the contact surface 45 of the valve body 47 is in contact with the second communication pipe 19, the exhaust gas flowing from the inlet pipe 15 passes through the communication hole 16 along the arrow A as shown in FIG. It flows through one communication pipe 18 and flows from the outlet pipe 17 to the outside. At this time, since the flow path of the exhaust gas in the muffler main body 2 is relatively narrow, the exhaust resistance in the muffler main body 2 is large, and the exhaust noise is low.

When the throttle of the engine is opened,
The throttle opening and the engine speed are set to the predetermined value S2.
And the throttle opening sensor 4
The sensor 9 and the engine speed sensor 50 detect a value near the point P2 shown in FIG. 4 and send a signal corresponding to this value to the control arithmetic unit 48. That is, as indicated by an arrow U3 in FIG. 2B, the control operation device 48 controls the switching valve 43 so that the pipe 42 communicates with the atmosphere-side pipe 44.

Since the second space 36 is originally filled with the exhaust gas at a pressure higher than the atmospheric pressure, the exhaust gas filling the second space 36 is filled with the arrow U shown in FIG.
3 and is discharged to the outside of the muffler device 1 and the second space 36
The pressure inside becomes equal to the atmospheric pressure. Therefore, the first space 35
A pressure difference is generated between the internal pressure and the pressure in the second space 36, and the pressure difference between the space 35 and the space 36 exceeds the elastic force of the spring 38.
As shown in FIG. 5, the contact surface 45 of the valve element 47 moves away from the one end 19a of the second communication pipe 19.

In this case, the exhaust gas flowing from the inlet pipe 15 flows through the communication hole 16 and the first communication pipe 18 along the arrow A as shown in FIG. One end 15a of pipe 15
Flows through the second communication pipe 19 and flows out of the outlet pipe 17 to the outside. At this time,
Since the flow path in the muffler main body 2 is relatively wide, the exhaust resistance in the muffler main body 2 is reduced, the exhaust loss of the engine is reduced, and the engine output is increased.

The muffler device 1 of the first embodiment uses an exhaust gas flowing through the muffler device 1
The mechanism for opening and closing the on-off valve 4 can be arranged around the muffler main body 2 in order to operate. Further, since a required mechanism such as the actuator 3 can be arranged around the muffler main body 2, the muffler device 1 can be reduced in size, the required occupied space is small, and the number of parts can be reduced.

Since the actuator 3 for operating the on-off valve 4 is controlled by using the control arithmetic unit 48, the mode switching required in the target engine operation region can be switched with high accuracy.

Since the orifice 27 and the throttle gap 24 are formed so that the flow path of the exhaust gas is narrowed, the flow rate of the exhaust gas introduced into the actuator 3 is limited, and the orifice 27 and the throttle gap 24 of the exhaust gas are restricted. After passing through, the exhaust gas is expanded to reduce the flow velocity and the temperature, so that the thermal shock of the exhaust gas acting on the diaphragm 32 can be reduced.

Further, the orifice 27 and the throttle gap 24
The exhaust gas passing through the fins 22
, The heat is radiated to the outside by the radiation fins 22 to lower the temperature.

Since the heat insulating materials 28 and 29 are provided between the muffler main body 2 and the bearing member 25 and between the bearing member 25 and the first casing 23, the heat of the muffler main body 2 is transferred to the diaphragm 32. To prevent it from being transmitted.

As a secondary effect, the contact surface 45 of the valve element 47 of the on-off valve 4 is connected to one end 19 of the second communication pipe 19.
a because it is formed substantially flat so as to contact
The on-off valve 4 may be installed on the muffler main body 2 so that the center line of the communication pipe 19 and the center line of the contact surface 45 are parallel to each other, so that the man-hour required for manufacturing the muffler device 1 is reduced. The Rukoto.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. As shown in FIG. 3, the muffler device 51 includes a muffler main body 52, an actuator 53, an on-off valve 54, and the like.

The muffler main body 52 is divided into a plurality of first chambers 62 and a second chamber 62 by partitions 60 and 61 as partition walls.
It is partitioned into a chamber 63 and a third chamber 64, and is provided with an inlet pipe 65, an outlet pipe 67, and the like.
The inlet pipe 65 penetrates through the first chamber 62 and the second chamber 63 from outside the muffler main body 52, and has a communication hole for ventilation such that one end 65 a is open to the third chamber 64 and faces the second chamber 63. 66 are provided. Outlet pipe 67
One end 67a is open to the first chamber 62 and penetrates the second chamber 63 and the third chamber 64, and the other end 67b is open to the outside of the muffler main body 52.

A first communicating pipe 68 and a second communicating pipe 69 are provided between the inlet pipe 65 and the outlet pipe 67. The first communication pipe 68 is provided on the inlet pipe 65 side, and penetrates a part of the partition wall 60 to communicate the first chamber 62 and the second chamber 63. The second communication pipe 69 is provided on the outlet pipe 67 side, has one end 69a opened to the first chamber 62, penetrates the partition walls 60, 61, and has the other end 69b opened to the third chamber 64. Thus, the first chamber 62 and the third chamber 64 communicate with each other. A hole 70 is provided in the muffler body 52 near a position facing the outlet pipe 67.

The communication hole 66, the first communication pipe 68, and the second communication pipe 69 constitute a communication portion described in this specification. The on-off valve 54 includes a valve body 97 that can be freely connected to and separated from one end 69 a of the second communication pipe 69, an end 87 a connected to the valve body 97, and the muffler body 5.
It has a shaft portion 87 extending in one direction so as to penetrate the outer wall of the second.

The valve body 97 is connected to the second communication pipe 6.
9 has a substantially flat contact surface 95 which is in contact with one end 69a of the second pipe 9 without any gap and exhibits sealing properties, and is formed to be larger than the outer diameter of the second communication pipe 69.

The shaft portion 87 is connected to the center line of the valve body 97 by the pressure receiving members 83 and 84 of the actuator 53 and the like.
Are supported so that the center line of the communication pipe 69 is substantially parallel to the center line. If the contact surface 95 of the valve element 54 can contact one end 69a of the second communication pipe 69, the valve element 97 can be directly connected to the diaphragm 8 without using the shaft part 87.
2 may be connected.

As shown in the figure, one end 69a of the second communication pipe 69 or a contact surface 95 of the valve body 97 is provided.
One of them may be provided with a valve seat 96 formed of a mesh member having a wire net or the like in order to improve the sealing property between the one end 69a and the contact surface 95.

The actuator 53 includes an operating portion 71 and a casing 73. The casing 73 is integrally joined to the outer surface of the muffler main body 52 so as to be airtight. The casing 73 forms an outer shell of the actuator 53 and has a hole 74.

The operating portion 71 is provided between the casing 73 and the muffler main body 52, and
Is provided with a diaphragm 82 that bisects the internal space of. The diaphragm 82 has a shape of being sandwiched between a first pressure receiving member 83 and a second pressure receiving member 84 which are formed in a substantially flat plate shape.
And a second space 86. Pressure receiving members 83, 8
4 and a substantially central portion of the diaphragm 82, a shaft 87
Is connected to the other end 87b.

A spring 88 is provided between the second pressure receiving member 84 and the casing 73. When the pressure in the first space 85 and the pressure in the second space 86 are equal to each other, the spring 88 The valve body 97 is kept in contact with one end 69a of the second communication pipe 69 by the elastic force of 88.

One ends 91a and 92a of pipes 91 and 92 are connected to a hole 70 provided in the muffler main body 52 and a hole 74 provided in the casing 73, respectively. Further, as shown in FIG. 3, the other ends 91b and 92 of the pipes 91 and 92, respectively.
A switching valve 93 is connected to b. As the switching valve 93, for example, a solenoid valve or the like is used, and a pipe 94 communicating with the atmosphere is connected, so that exhaust gas is supplied from the pipe 91 to the pipe 92 or from the pipe 92 to the pipe 94
It is possible to switch to flow to.

Reference numeral 98 in FIG. 3 denotes a control arithmetic unit which is an example of a control means. The control arithmetic unit is connected to a throttle opening sensor 99 and an engine speed sensor 100, and operates in accordance with the throttle opening and the engine speed. It has a function of controlling the switching valve 93. The control arithmetic unit 98 may be configured, for example, by adding a function to the ECU, or may be configured using a dedicated arithmetic unit.

The muffler device 51 configured as described above
Is controlled by controlling the pressure in the spaces 85, 86 by changing the flow of the exhaust gas in the pipes 91, 92, 94 using the switching valve 93 in accordance with the command output from the control arithmetic unit 98. The flow path of the exhaust gas in the muffler main body 52 is changed by moving the diaphragm 82 and the on-off valve 54 to a position indicated by a solid line in FIG. 3 and a position indicated by a two-dot chain line Q2.

The timing of switching between the low noise mode and the high output mode by changing the flow path of the exhaust gas in the muffler body 52 is based on the engine speed and the throttle opening. As shown in FIG. 4, when the engine speed is equal to or more than a predetermined value R1 and less than R and the throttle opening is fully opened (100
%) Or more when the engine speed is equal to or more than the predetermined value R and the throttle opening is equal to or more than the second predetermined value S2 near the idle load, that is, hatching in FIG. In the region indicated by, the high output mode is set, and when the throttle opening is less than the second predetermined value S2, or when the engine speed is less than the predetermined value R and the throttle opening is equal to or more than the second predetermined value S2, When the engine speed is less than the predetermined value S1 or when the engine speed is less than R1, the low noise mode is set.

Next, the operation of the muffler device 51 of the above embodiment will be described. First, for example, when the engine is idling and the vehicle is stopped, the throttle opening sensor 99 and the engine speed sensor 10
A value of 0 detects the value of the throttle opening near the point P1 shown in FIG. 4 and sends a signal corresponding to this value to the control arithmetic unit 98.
In this case, the control arithmetic unit 98 determines that the flow path of the exhaust gas is
The switching valve 93 is controlled so as to be formed from 1 to the pipe 92.

The hole 7 provided in the muffler main body 52
The exhaust gas that has flowed into the pipe 91 from the pipe 0 flows through the pipe 92, passes through the hole 74 of the casing 73, and passes through the second space 8.
Flow into 6. For this reason, the pressure in the first space 85 and the second
Is substantially equal to the pressure in the space 86, and the contact surface 95 of the valve body 97 comes into contact with one end 69a of the second communication pipe 69 due to the repulsive load of the spring 88. For this reason, the exhaust gas flowing from the inlet pipe 65 passes through the communication hole 66 along the arrow C in the drawing, and the first communication pipe 6
8 flows out of the outlet pipe 67 to the outside. At this time, since the flow path of the exhaust gas in the muffler main body 52 is relatively narrow, the exhaust resistance in the muffler main body 52 is large, and the exhaust noise is low.

When the throttle of the engine is opened,
The throttle opening and the engine speed are set to the predetermined value S2.
And R, the throttle opening sensor 9
9 and the engine speed sensor 100 are at point P2 shown in FIG.
A value such as the vicinity is detected, and a signal corresponding to this value is sent to the control arithmetic unit 98. The control arithmetic unit 98 controls the switching valve 93 so that the pipe 92 communicates with the pipe 94 on the atmosphere side.

Since the exhaust gas is originally filled in the second space 86 at a pressure higher than the atmospheric pressure, the exhaust gas filled in the second space 86 passes through the pipe 92 and the pipe 94 to the muffler. The pressure is released outside the device 51 and the pressure in the second space 86 becomes equal to the atmospheric pressure. Therefore, a pressure difference is generated between the pressure in the first space 85 and the pressure in the second space 86, and the pressure difference between the space 85 and the space 86 exceeds the elastic force of the spring 88. Moves to the left as shown by the two-dot chain line Q2 in FIG. 3, and the contact surface 95 of the valve body 97 is moved to one end 69 of the second communication pipe 69.
a.

In this case, the exhaust gas flowing from the inlet pipe 65 flows in the first communication pipe 68 from the communication hole 66 along the arrow C in FIG.
Flows from the one end 65a of the inlet pipe 65 through the second communication pipe 69, and flows out from the outlet pipe 67 to the outside. At this time, since the flow path in the muffler main body 52 is relatively wide, the exhaust resistance in the muffler main body 52 is reduced, so that the exhaust loss of the engine is reduced and the engine output is increased.

In the muffler device 51 of the second embodiment, the first space 85 partitioned by the diaphragm 82 and the like is formed in the muffler main body 52, so that the muffler device 1 shown in the first embodiment is different from that of the first embodiment. The size can be further reduced, and the required occupied space is further reduced.

[0072]

According to the first aspect of the present invention, it is possible to drive the actuator and open and close the on-off valve by using the pressure of the exhaust gas passing through the muffler device, so that the negative pressure pipe is connected from the engine to the muffler device. It is possible to operate the on-off valve without providing it. Further, unlike the case of using the intake negative pressure, the exhaust gas can be used for opening and closing the on-off valve, so that the muffler device can be reduced in size and the number of parts can be reduced.

In addition, since the actuator is driven to open and close the on-off valve in accordance with the operating state of the engine, it is expected that the mode can be accurately switched in the target engine operating range.

According to the present invention, a mechanism such as an actuator that opens and closes the on-off valve using the pressure of the exhaust gas includes:
Since the muffler device is integrated around the muffler body, the size of the muffler device can be further reduced. In addition, since the joining of the casing containing the diaphragm to the muffler body also serves as a seal for the shaft connecting the diaphragm and the valve body, a structure for slidably sealing the shaft is not required. Also, since the muffler device is reduced in size and the number of parts is reduced, the size and the configuration are simplified.

[Brief description of the drawings]

FIG. 1 is a sectional view of a muffler device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing an operation state of the muffler device shown in FIG.

FIG. 3 is a sectional view of a muffler device according to a second embodiment of the present invention.

FIG. 4 is a control map showing mode switching in the muffler device of the present invention.

FIG. 5 is a sectional view showing a conventional first muffler device.

FIG. 6 is a sectional view showing a second conventional muffler device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Muffler device 2 ... Muffler main body 3 ... Actuator 4 ... On-off valve 10 ... Partition wall (partition wall) 11 ... Partition wall (partition wall) 12 ... 1st chamber 13 ... 2nd chamber 14 ... 3rd chamber 16 ... Communication hole (communication) 18) First communication pipe (communication part) 19 ... Second communication pipe (communication part) 22 ... Heat radiation fin (heat radiation means) 23 ... First casing 28 ... Heat insulation material (heat insulation means) 29 ... Heat insulation material (Insulation means) 30 ... second casing 32 ... diaphragm 35 ... first space 36 ... second space 37 ... shaft part 45 ... contact surface 47 ... valve element 48 ... control arithmetic unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 35/00 378 F02D 35/00 378A (72) Inventor Keigo Ogawa 5-33-8 Shiba 5-chome, Minato-ku, Tokyo Mitsubishi Motors Inside (72) Inventor Yasuo Suzuki 2480 Kuno, Odawara City, Kanagawa Prefecture Inside the Mikuni Odawara Plant (72) Inventor Hirofumi Imai 2480 Kuno, Odawara City, Kanagawa Prefecture Inside the Mikuni Odawara Plant (56) References JP-A-4-124418 (JP, A) JP-A-61-164013 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01N 1/08 F01N 1/00 F01N 7/08 F02D 9/04 F02D 11/08 F02D 35/00 378

Claims (1)

(57) [Claims] 1. A muffler body having an interior partitioned into a plurality of chambers by a partition wall, a communication portion for communicating the partitioned chambers, an on-off valve for opening and closing the communication portion, and a muffler body. an actuator for opening and closing the on-off valve actuated by the pressure of the exhaust gas of the engine, the muffler device having a control means for controlling the pressure of the exhaust gas to actuate the actuator in response to operation of the engine, the on-off valve Is detachable from the communication portion provided in the muffler main body.
A valve element, and penetrates the outer wall of the muffler body from the valve element
And a shaft extending in a direction, wherein the actuator is joined to an outer surface of the muffler body.
Casing and the displacement accommodated in this casing
And a flexible diaphragm.
Form a first space on one side where the pressure of the exhaust gas is applied.
Pressure on the other side of the diaphragm
Configured to form a second space to which atmospheric pressure is applied;
The shaft of the valve body is connected to the diaphragm,
The on-off valve according to the introduction of gas pressure or atmospheric pressure
A muffler device that opens and closes .