JP2002089229A - Muffler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the noise of a muffler, to improve the tone quality and to reduce the back pressure. SOLUTION: In this muffler comprising an inlet pipe 74 inserted into an inlet side hollow part 58 of a muffler body 51, and connected to an exhaust manifold of an engine, and provided with an inflow port 63 formed by a number of holes 64 for allowing the exhaust gas from the inlet pipe 74 to flow to the inlet side hollow part 58, the inflow port 63 is composed of a first inflow port 63A for allowing the exhaust gas to flow into the inlet side hollow part 58, and a second inflow part 63B for allowing the exhaust gas into the inlet side hollow part 58 later in comparison with the first inflow port 63A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler used for a vehicle such as a backhoe.

[0002]

2. Description of the Related Art Conventionally, there is a muffler (muffler) employed in a backhoe as shown in FIGS.
9 and 10, the muffler 91 mainly includes a muffler main body 92, an inlet pipe 93 connected to an exhaust manifold of the engine, and an outlet pipe 94 discharged from the muffler main body 92 to the outside. The muffler main body 91 is configured by closing both ends of a flat cylindrical body 91A with a pincer 91B.

[0003] Inside the muffler main body 91, a perforated plate is formed in the same flat cylindrical shape as the cylindrical body 91A of the muffler main body 91, and the inner cylinder 95 is slightly smaller than the cylindrical body 91A.
Are provided between the pincers 91B. Inner cylinder 9
Glass wool is filled between 5 and the cylinder 91A of the muffler main body 91. The inside of the muffler body 91 is divided into an inlet-side cavity 99, an intermediate cavity 100, a resonance chamber 101, and an outlet-side cavity 102 from the right by three partition plates 96, 97, 98.

[0004] An inlet pipe 93 is inserted into the inlet-side hollow portion 99. The inlet pipe 93 has a large number of holes through which exhaust gas from the engine flows from the inlet pipe 93 into the inlet-side hollow portion 99. The parts 104 are provided evenly in the exhaust gas flow direction. Further, in the muffler main body 91, a communication pipe 105 that penetrates the partition plates 96 and 97 and communicates the inlet-side cavity 99 and the resonance chamber 101 is provided.
The communication pipe 105 is formed with a flow portion 106 including a large number of holes through which exhaust gas flows from the inlet-side cavity 99 to the intermediate cavity 100.

In the muffler main body 91, a first distribution pipe 107 penetrating the partition plate 97 and a partition plate 9 are provided.
8 and a second distribution pipe 109 that covers the distribution pipe 107. The first distribution pipe 107 includes a distribution section 108 having a large number of holes through which exhaust gas flows from the intermediate cavity 100 to the first distribution pipe 107, and a second distribution pipe 109 from the first distribution pipe 107. And a flow portion 112 composed of a large number of holes through which the exhaust gas flows.

The second flow pipe 109 has an outlet side hollow portion 102 from the second flow pipe 109.
Section 11 composed of a large number of holes through which exhaust gas flows
0 is formed. The outlet side cavity 10
2, an outlet pipe 94 is inserted into the outlet pipe 94. The outlet pipe 94 has an outlet 111 composed of a number of holes for allowing exhaust gas to flow from the outlet-side cavity 102 to the outlet pipe 94 in the exhaust gas flow direction. Are evenly formed.

[0007]

When high-temperature and high-pressure exhaust gas discharged from an engine is directly discharged, an extremely loud explosion sound is generated. Therefore, the purpose of the muffler is to reduce the exhaust noise, and various measures have been taken to increase the muffler effect of the muffler. However, the muffler having the conventional structure has a sufficient muffler effect. It wasn't, but there was still room for improvement.

Accordingly, the present invention provides a muffler noise reduction,
The purpose is to improve sound quality.

[0009]

The first technical means taken by the present invention to achieve the above object is a muffler body 5
1 and an inlet pipe 74 that is inserted into the inlet-side cavity 58 of the engine 9 and is connected to the exhaust manifold 76 of the engine 9.
The inlet side hollow portion 5
In a muffler provided with an inflow portion 63 including a large number of holes 64 through which exhaust gas flows into the exhaust gas 8, the inflow portion 63 includes:
A first inflow portion 63A that allows exhaust gas to flow into the inlet-side cavity portion 58, and a second inflow portion 63B that causes exhaust gas to flow into the inlet-side cavity portion 58 later than the first inflow portion 63A are provided. It is characterized by comprising.

The number of holes 64 forming the second inflow portion 63B is preferably larger than the number of holes 64 forming the first inflow portion 63A. The second technical means is an outlet pipe 7 which is inserted into the outlet side cavity 68 of the muffler body 51 and discharges exhaust gas to the outside.
7, the outlet pipe 77 is provided with an outlet portion 85 including a large number of holes 84 for allowing exhaust gas to flow from the outlet side cavity portion 68 to the outlet pipe 77. First outflow portion 85A that flows out to outlet pipe 77
And a second outflow portion 85B that allows the exhaust gas to flow out to the outlet pipe 77 later than the first outflow portion 85A.
And is provided.

The number of holes 84 forming the second inflow portion 85B is preferably larger than the number of holes 84 forming the first outflow portion 85A.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 5 and 6, reference numeral 1 denotes a backhoe exemplified as a turning work machine. The backhoe 1 is mainly composed of an upper revolving unit 2 and a lower traveling device 3. Even if the revolving base 6 is pivoted about a vertical axis, the rear surface of the revolving platform 6 has a lateral width of the traveling device 7. This is called a small rear small turning backhoe in which the rear side of the turntable 6 is formed in a plan view arc shape (substantially arc shape) so as not to protrude outside.

The traveling direction of the backhoe 1 (the left-right direction in FIG. 5) is referred to as the front-rear direction, and the lateral direction perpendicular to the front-rear direction (the direction penetrating the plane of FIG. 5) is referred to as the left-right direction. The traveling device 3 rotatably supports an idler 3B, a driving wheel 3C, a track roller 3D, and a carrier roller 3F on both left and right sides of a track frame 3A, and a rubber crawler traveling body 4 (or an iron crawler traveling type). And a crawler-type traveling device in which the drive wheels 3C are driven by a hydraulic motor or the like. A dozer 5 is provided at the front of the traveling device 3.

The revolving unit 2 includes a revolving base 6 supported on a traveling device 3 so as to be revolvable about a vertical axis, a working device (excavator) 7 provided in front of the revolving platform 6, Swivel 6
A driver's seat 8 provided above, an engine 9 (four-cycle engine), a fuel tank 10, a hydraulic pump 11, a hydraulic oil tank 12, a control valve 13, a radiator 14,
Oil cooler 15, reserve tank 16, battery 1
The system includes various devices mounted on the swivel 6 such as a muffler 7, an muffler 18, and an air cleaner 25.

The driver's seat 8 is disposed halfway in the front-rear direction of the swivel base 6 and to the left from the center in the left-right direction. The revolving base 6 is attached and fixed to a revolving frame and a rear part of the revolving frame, and balances weight with a working device 7 provided on a front part of the revolving base 6 together with the engine 9 and constitutes a rear part of the revolving base 6. And a counter weight 20 (protector). Further, the left and right side surfaces, the front surface, the front side of the driver's seat 8 on the front surface, and the upper surface of the turning frame are appropriately covered with a cover body 23 and the like.

The revolving frame includes a revolving substrate supported on the traveling device 3 via a revolving bearing 21 so as to be revolvable about a vertical axis, and a reinforcing member and various devices are mounted on the revolving substrate. A fixing member or the like for fixing is fixed. A pair of upper and lower support brackets 26 are provided at the front of the revolving frame so as to protrude forward from the revolving table 6.
Are supported to be able to swing left and right around the vertical axis. A boom 28 supported by the swing bracket 27 so as to be swingable about a horizontal axis, an arm 29 supported at a tip side of the boom 28 so as to be swingable about the horizontal axis, and a tip side of the arm 29 The working device 7 is mainly composed of a bucket 30 attached so as to be able to perform a squeeze and dump operation. The boom 28, the arm 29, and the bucket 30 are each composed of a boom cylinder 31, an arm cylinder 32, Operable by the cylinder 33.

At the rear of the swivel 6 and behind the driver's seat 8, an engine 9 is disposed horizontally (so that the axis of the crankshaft is directed to the left and right). Has a hydraulic pump 1 that supplies hydraulic oil to various hydraulic equipment.
1, a muffler 18 is disposed above the hydraulic pump 11, and an air cleaner 25 is disposed above the muffler 18. A radiator 14, an oil cooler 15, a reserve tank 16 and a battery 17 are arranged on the right side (the other side on the right and left) of the engine 9, and a fuel tank 10 is arranged on the front side of the engine 9 and on the left side of the swivel 6. , The front of the engine 9 and the swivel 6
A hydraulic oil tank 12 for storing hydraulic oil for operating hydraulic equipment is disposed on the right side of the vehicle and in front of the radiator 14 and the like.
In front of the hydraulic oil tank 12, a control valve 13 is formed by vertically stacking control valves for controlling each hydraulic device.
Is arranged.

The engine 9, the radiator 14, the oil cooler 15, the hydraulic oil tank 12, the control valve 13 and the like are formed so as to protrude upward from the swivel 6 and the engine 9, the hydraulic pump 11, the muffler 18, the air cleaner 25 and the like. The upper front side, the front side, and the left side of the upper portion of the disposition space above the revolving base 6 are covered with a fixed cover 35. The rear side of the space above the swivel 6 in the space where the engine 9, the hydraulic pump 11, the radiator 14, the muffler 18, the air cleaner 25, and the like is disposed is a bonnet 3.
The hood 36 is attached to a support frame or a fixed cover 35 (not shown) via a hinge so as to be swingable up and down, and is openable and closable.

The hydraulic oil tank 12 and the control valve 13 are covered by a tank cover 37. The tank cover 37 extends to the right of the fixed cover 35, and includes a radiator 14, an oil cooler 15, and a reserve tank 16. And the battery 17 and the like. In front of the driver's seat 8, a pair of left and right driving control levers 3 for operating the right and left traveling bodies 4 separately are provided.
8L and 38R are arranged, and control tables 39L and 39R are arranged on both left and right sides of the driver's seat 8.

On the right control platform 39R, a boom / bucket operating lever 40 for operating the boom 28 and the bucket 30, and a dozer operating lever 41 for operating the dozer 5 are provided.
An accelerator lever 42 for controlling the rotation of the engine;
And a lock lever 24. The left control table 39L is provided with a rotation motor for rotating the rotation table 6, a rotation / arm operation lever 43 for operating the arm 29, and a lock lever 44.

By operating the lock levers 24 and 44, the operation of the boom 28 and the bucket 30 by the boom / bucket operation lever 40 and the operation of the swing motor and the arm 29 by the swing / arm operation lever 43 are disabled or possible. I do. The radiator fan 50 provided on the right side of the engine 9 is of a suction type that sucks air from the outside. An outside air intake is formed on the rear side of the side surface of the tank cover 37, and the sucked air is supplied to the swivel. 6 so as to escape downward.

As shown in FIGS. 7 and 8, the hydraulic pump 1
Reference numeral 1 denotes a muffler 18 which is attached and fixed to the left side of a pump housing 71 which is attached and fixed to the left side of the engine 9.
Are arranged above the hydraulic pump 11 in such a manner as to shift outward in the left-right direction as going toward the front A (the longitudinal direction of the muffler 18 shifts outward in the left-right direction as going toward the front A). The pump housing 71 is attached to a mounting base 73 fixed to the upper left side of the pump housing 71. In this manner, by arranging the muffler 18 in an inclined manner, even if the engine 9 is arranged to be close to the bonnet 36, the muffler 18 can be properly positioned above the hydraulic pump 11 beside the engine 9. It is configured.

An inlet pipe 74 is provided on the front right side of the muffler main body 51 of the muffler 18. The inlet pipe 74 is connected to an exhaust manifold 76 of the engine 9 via a pipe 75 with a flange. On the rear left side of the muffler main body 51, an outlet pipe 77 is provided in a downwardly bent shape, and an exhaust pipe 78 (including a hose) is connected to the outlet pipe 77. , The discharge side end of which is formed with an opening (not shown) in the lower portion of the counterweight 20 or the like, for example, and is arranged so that exhaust gas from the engine 9 is discharged from this opening.

As described above, the noise reduction effect is improved by extending the exhaust pipe 78 to the bottom of the swivel 6. Hereinafter, the muffler 18 will be described in detail with reference to FIGS. The muffler main body 51 is configured by closing both ends of a flat cylindrical body 51A with a pincer 51B.
The stay 52 which is detachably attached to is fixed by welding or the like. The inside of the muffler main body 51 is partitioned by a pair of partition plates 53 and 54 into three chambers on the inlet side, the outlet side, and the middle (in the axial direction) therebetween.

In the chamber on the inlet side in the muffler main body 51, an inner cylinder 55, which is formed in a flat cylindrical shape similar to the cylindrical body 51A of the muffler main body 51 and is slightly smaller than the cylindrical body 51A, It is provided over the pincer 51B. The inner cylinder 55 is formed of, for example, a perforated plate, and is provided with small holes over the entire surface. Between the inner cylinder 55 and the muffler main body 51 (the cylindrical body 51A), there is a glass wool 56 for eliminating high frequency, Sound absorbing material. Further, inside the inner cylinder 55, two inlet-side cavities 58, 59 in the axial direction are formed by a partition plate 57.

An intermediate room in the muffler main body 51 is a resonance chamber 60, and a perforated plate 61 is provided in the resonance chamber 60 so as to face the partition plate 54 on the outlet side. A space between the partition plate 54 and a sound absorbing material such as glass wool 56 for eliminating high frequency is filled. In the chamber on the outlet side in the muffler main body 51, an inner cylinder 62 which is formed in a flat cylindrical shape similar to the cylindrical body 51A of the muffler main body 51 and is slightly smaller than the cylindrical body 51A is provided with the partition plate 54 and the pincer 51B. Is provided over,
The inside of the inner cylinder 62 is an outlet-side cavity 68.

The inner cylinder 62 is formed of, for example, a perforated plate, and is provided with small holes over the entire surface. The high frequency is eliminated between the inner cylinder 62 and the muffler main body 51 (cylindrical body 51A). A sound absorbing material such as glass wool 56 is filled. The upstream inlet-side hollow portion 58 (this is called a first inlet-side hollow portion, and the downstream inlet-side hollow portion 5
9 is referred to as a second inlet side hollow portion), the inlet pipe 74 is inserted thereinto.
Is closed at the insertion side.

The inlet pipe 74 is provided with an inflow portion 63 composed of a number of holes 64 through which exhaust gas from the engine 9 flows into the first inlet side cavity portion 58. The inflow section 63 is provided with a first inflow section 63A and a second inflow section 63B provided at a distance from the first inflow section 63A (displaced). . In the first inflow portion 63A, a row in which three holes 64 are arranged in the axial direction and a row in which two holes 64 are arranged in the axial direction are formed alternately in the circumferential direction by eight rows. It is composed of a total of 40 holes 64.

Further, the second inflow portion 63B has an axially
The row in which the two holes 64 are arranged is formed in 16 rows in the circumferential direction, and is composed of a total of 80 holes 64. The number of holes is larger than the first inflow portion 63A, and the opening area is large. It is formed as follows. Further, the first inflow portion 63A and the second inflow portion 63A
The holes 64 forming the inflow portion 63B are formed in a staggered shape as illustrated in FIG. Further, the first inlet side cavity portion 58 and the resonance chamber 60 are communicated with each other by a communication pipe 65 that penetrates the partition plates 53 and 57 and is disposed near the first inflow portion 63A. A flow portion 67 including a large number of holes 66 for flowing exhaust gas from the first inlet side cavity portion 58 to the second inlet side cavity portion 59 is formed.

The flow portion 67 has six holes 66 in the axial direction.
Are arranged alternately in the circumferential direction in a row in which five holes 66 are arranged in the axial direction, and a total of 88 holes 66 are formed. Also, the partition plates 54 and 53
Through the perforated plate 61 and the second inlet side cavity 5
A communication pipe 69 that communicates the outlet 9 with the outlet side cavity 68 is provided. In the portion of the communication pipe 69 inserted into the second inlet side hollow portion 59, a flow portion 81 including a large number of holes 80 is formed.

The flow portion 81 has six holes 80 in the axial direction.
, And a row in which five holes 80 are arranged in the axial direction are alternately formed in eight rows in the circumferential direction, and are composed of a total of 88 holes 80. In addition, of the communication pipe 69,
In the portion inserted into the outlet side cavity 68, a flow portion 82 including a number of holes 82 is formed. The flow portion 82 has a row in which two holes 82 are arranged in the axial direction and a row in which one hole 82 is arranged in the axial direction, which are alternately formed in eight rows in the circumferential direction. The hole 82 is formed.

An outlet pipe 77 is inserted into the outlet-side cavity 68, and the outlet pipe 7
The end on the insertion side of 7 is closed. Further, the exhaust gas is supplied to the outlet pipe 77 through the outlet side cavity 6.
An outflow portion 85 composed of a large number of holes 84 for outflow from the outlet 8 is provided. The outflow portion 85 is provided with a first outflow portion 65A.
And a second outflow portion 85B provided at a distance from the first outflow portion 85A (displaced).

The communication pipe 69 has a first outlet portion 85A.
Located on the side. In addition, the first outflow portion 85A includes a row in which four holes 84 are arranged in the axial direction, and three holes 8 in the axial direction.
The four rows are arranged alternately in the circumferential direction in eight rows each, and are composed of a total of 56 holes 84. Also,
The second outflow portion 85B has a total of 96 holes 84 in which a row of six holes 84 arranged in the axial direction is formed in the circumferential direction, and the second outflow portion 85B is composed of a total of 96 holes 84. The holes are also formed so as to have a large number of holes and a large opening area.

The first outflow portion 85A, the second outflow portion 85B, and the holes 84, 66, 80, 82 constituting the flow portions 67, 81, 83 are provided with the first inflow portion 63A and the second inflow portion. Are formed in a staggered manner, like the holes 64 constituting the inflow portion 63B. In the muffler 18 having the above-described configuration, the exhaust gas from the engine 9 first flows into the first inlet-side cavity 58 from the first inlet 63A, and then delays from the second inlet 63B to the inlet-side cavity. Into the section 58. As a result, exhaust interference is reduced, exhaust gas passage resistance is reduced, back pressure can be reduced (power loss due to back pressure can be reduced), and exhaust sound propagates to the resonance chamber 60 with a time lag. Thus, noise is reduced and sound quality is improved.

The exhaust gas that has flowed into the first inlet-side cavity 58 flows into the second inlet-side cavity 59 through the flow portion 67, and also flows into the communication pipe 69 through the flow portion 81. It flows into the outlet side cavity 68 via the circulation part 83. Outlet side cavity 6
The exhaust gas that has flowed into the first outflow section 85
A flows into the outlet pipe 77 from A, and flows into the outlet pipe 77 from the second outflow portion 85B with a delay,
It is discharged outside through the exhaust pipe 78.

Also on the exhaust gas discharge side, exhaust gas is discharged with a time lag, thereby reducing exhaust interference, reducing exhaust gas passage resistance, and reducing back pressure (power loss due to back pressure). Exhaust noise is propagated with a time lag, so that noise is reduced and sound quality is improved. Further, by increasing the number of holes 64 and 84 which flow later, the exhaust pulsation of the engine 9 is reduced.

[0037]

According to the present invention, there is provided an inlet pipe 74 inserted into the inlet side cavity 58 of the muffler body 51 and connected to the exhaust manifold 76 of the engine 9. In a muffler provided with an inflow portion 63 composed of a large number of holes 64 for allowing exhaust gas to flow from 74 into the inlet side cavity portion 58, the inflow portion 63 is used for a first inflow where exhaust gas flows into the inlet side cavity portion 58. Part 6
3A and a second inflow section 6 that allows the exhaust gas to flow into the inlet-side cavity 58 later than the first inflow section 63A.
3B, the exhaust noise is propagated with a time lag, thereby reducing noise and improving sound quality.

Further, the holes 6 forming the first inflow portion 63A are formed.
4, the number of holes 64 constituting the second inflow portion 63B is larger than the number of holes 64.
By increasing the number of holes, there is an effect that exhaust gas and exhaust noise can be satisfactorily flowed. An outlet pipe 7 inserted into the outlet side cavity 68 of the muffler main body 51 and discharging exhaust gas to the outside.
7, the outlet pipe 77 is provided with an outlet 85 comprising a large number of holes 84 for allowing exhaust gas to flow from the outlet side cavity 68 to the outlet pipe 77. First outflow portion 85A that flows out to outlet pipe 77
And a second outflow portion 85B that allows the exhaust gas to flow out to the outlet pipe 77 later than the first outflow portion 85A.
With this configuration, the exhaust sound is transmitted with a time lag, thereby reducing noise and improving sound quality.

The hole 8 forming the first outflow portion 85A
4, the number of holes 84 constituting the second inflow portion 85B is smaller than the number of holes 84.
By increasing the number of holes, there is an effect that exhaust gas and exhaust noise can be satisfactorily flowed.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line BB of FIG.

FIG. 2 is a side view of the muffler.

FIG. 3 is a bottom view of the muffler.

FIG. 4 is a development view of an inflow portion and the like.

FIG. 5 is a side view of the backhoe.

FIG. 6 is a plan view of the backhoe.

FIG. 7 is a plan view of a muffler arrangement section.

FIG. 8 is a side view of the muffler arrangement section.

FIG. 9 is a side view of a muffler according to a conventional example.

FIG. 10 is a sectional view taken along the line CC of FIG. 9;

[Explanation of symbols]

 9 Engine 51 Muffler main body 59 Inlet side cavity 63 Inflow 63A First inflow 63B Second inflow 64 Hole 68 Outlet side cavity 74 Inlet pipe 77 Outlet pipe 76 Exhaust manifold 84 Hole 85 Outflow 85A 1 outflow section 85B 2nd outflow section

Claims (4)

[Claims] An inlet pipe (74) inserted into an inlet side cavity (58) of a muffler body (51) and connected to an exhaust manifold (76) of an engine (9). )
A number of holes (64) through which exhaust gas flows from the inlet pipe (74) to the inlet side cavity (58).
A muffler provided with an inflow section (63) comprising: a first inflow section (63A) for allowing exhaust gas to flow into the inlet-side cavity (58); and a first inflow section. (63A), the second inflow section (63) for allowing the exhaust gas to flow into the inlet-side cavity (58).
B). 2. The number of holes (64) forming a second inflow portion (63B) is larger than the number of holes (64) forming a first inflow portion (63A). The muffler according to claim 1, wherein 3. An outlet pipe (77) inserted into the outlet side cavity (68) of the muffler body (51) and discharging exhaust gas to the outside, the outlet pipe (77) having an outlet side cavity. (6
8) In a muffler provided with an outflow portion (85) composed of a large number of holes (84) for allowing exhaust gas to flow from an outlet pipe (77) to an outlet pipe (77), And a second outlet (85A) that allows exhaust gas to flow out to the outlet pipe (77) later than the first outlet (85A).
B). 4. The number of holes (84) constituting the second inflow portion (85B) is larger than the number of holes (84) constituting the first outflow portion (85A). The muffler according to claim 3, wherein