JP4448797B2 - General-purpose engine muffler support structure - Google Patents

Description

  The present invention relates to a muffler support structure for a general-purpose engine that is attached to an exhaust port of an engine via an exhaust pipe.

As a muffler support structure for a general-purpose engine, an exhaust pipe attached to an exhaust port of an engine and a muffler attached to the exhaust pipe is practically used.
A practical general-purpose engine muffler support structure is practically sufficient if an exhaust pipe is attached to the exhaust port of the engine, a muffler is attached to the exhaust pipe, and the exhaust pipe and muffler mounting part have the required rigidity. It was.

As such a muffler support structure for a general-purpose engine, an exhaust port provided on the side of the engine and a muffler connected to the exhaust port is known (for example, see Patent Document 1).
Japanese Utility Model Publication No. 59-194521 (first page, FIG. 1)

  FIG. 15 is a diagram for explaining a conventional basic configuration. A muffler support structure 330 of a general-purpose engine is provided with an exhaust port 332 on the side of the engine 331, and an exhaust pipe 334 is integrally extended from the muffler 333. The tip of 334 is fixed to the exhaust port 332 with bolts 335 and 335.

However, since the muffler support structure 330 of the general-purpose engine supports the muffler 333 in a cantilever manner via the exhaust pipe 334 on the exhaust port 332 of the engine 331, depending on the use of the engine 331, the vibration of the muffler 333 increases, It may not be suitable for the application.
Further, in the muffler support structure 330 of the general-purpose engine, the weight of the engine 331 may increase in order to increase the rigidity of the exhaust pipe 334 in order to firmly support the muffler 333.

  That is, there is a demand for a muffler support structure for a general-purpose engine that can reduce the vibration of the muffler and reduce the weight of the engine.

  The present invention provides a muffler support structure for a general-purpose engine that solves the problem that the vibration of the muffler increases and can reduce the noise of the muffler. Also, the rigidity of the support member such as the exhaust pipe is increased for the muffler support. It is an object of the present invention to provide a muffler support structure for a general-purpose engine that solves the problem that the engine becomes heavier in order to secure the engine and can reduce the weight of the engine.

  The invention according to claim 1 is a general-purpose engine muffler support structure in which one end of an exhaust pipe is connected to an exhaust port of the engine and a muffler is attached to the other end of the exhaust pipe. In addition, the left and right exhaust port side mounting portions are formed on one end with the center of the exhaust pipe interposed therebetween, and the left and right muffler side connecting portions on the other end with the center of the exhaust pipe sandwiched in order to connect the other end to the muffler. The muffler support part that supports the muffler is formed on the engine side, and the left and right sides of the muffler are positioned so that the center of gravity of the muffler is positioned in the triangle connecting the left and right exhaust port side mounting parts and the muffler support part in plan view. An exhaust port side mounting portion and a muffler support portion are arranged.

  For example, if it is possible to reduce the vibration of the muffler, it is preferable because the quietness of the general-purpose engine can be increased. If the muffler can be supported effectively, the weight of the engine is increased. This is advantageous because it can be minimized.

  Therefore, in plan view, the left and right exhaust port side mounting portions and the muffler support portions are arranged so that the center of gravity of the muffler is positioned in the triangle connecting the left and right exhaust port side mounting portions and the muffler support portions. Can be supported at three points surrounding the center of gravity.

The invention according to claim 2 is characterized in that the left and right muffler side connecting portions are offset to the outside of the triangle.
By offsetting the left and right muffler side connecting portions to the outside of the triangle, it is possible to further prevent the muffler from shaking.

In the invention according to claim 3, the left and right exhaust port side mounting portions are arranged at symmetrical positions with respect to the center of the other end of the exhaust pipe, and a line segment connecting the left and right exhaust port side mounting portions is used as a base. A muffler support portion is formed at the apex of the equal piece triangle.
The left and right exhaust port side mounting parts are arranged symmetrically with respect to the center of the other end of the exhaust pipe, and the muffler is supported at the apex of an isosceles triangle with the line segment connecting the left and right exhaust port side mounting parts as the base By forming the portions, the weight of the muffler can be apportioned by the left and right exhaust port side mounting portions and the muffler support portions.

The invention according to claim 4 is characterized in that the muffler is integrally provided with a support bracket attached to the muffler support portion.
By integrally providing the muffler with a support bracket that is attached to the muffler support portion, an increase in the weight of the engine can be minimized in order to efficiently support the muffler.

  In the invention according to claim 1, the left and right exhaust port side attachment portions and the muffler support portions are arranged so that the center of gravity of the muffler is positioned in a triangle connecting the left and right exhaust port side attachment portions and the muffler support portion in a plan view. Since it is arranged, the muffler can be supported at three points surrounding the center of gravity. As a result, there is an advantage that the vibration of the muffler can be reduced and the noise generated from the muffler can be reduced.

  In the invention according to claim 2, since the left and right muffler side connecting portions are offset to the outside of the triangle, it is possible to further prevent the muffler from shaking. As a result, there is an advantage that further muffler vibration can be reduced.

  In the invention according to claim 3, the left and right exhaust port side mounting portions are arranged at symmetrical positions with respect to the center of the other end of the exhaust pipe, and a line segment connecting the left and right exhaust port side mounting portions is the bottom. Since the muffler support portion is formed at the apex of the equilateral triangle, there is an advantage that the weight of the muffler can be apportioned by the left and right exhaust port side mounting portions and the muffler support portion.

  In the invention according to claim 4, since the muffler is integrally provided with a support bracket attached to the muffler support portion, an increase in the weight of the engine can be minimized in order to efficiently support the muffler. As a result, for example, there is an advantage that the weight of the general-purpose engine can be reduced as compared with the case where the exhaust pipe is cantilevered and the rigidity of the exhaust pipe is improved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a front view of a general-purpose engine that employs a muffler support structure according to the present invention. An engine (general-purpose engine) 10 as an internal combustion engine includes a crankcase 13 that stores oil (lubricating oil) 12, and the crankcase. A crankshaft 14 as an output shaft that is horizontally and rotatably mounted on 13, a single cylinder block 15 that is formed integrally and inclined on the crankcase 13, and can slide on a cylinder 16 of the cylinder block 15. , A connecting rod 18 for connecting the piston 17 and the crankshaft 14, a cylinder head 21 attached to the opening 19 of the cylinder block 15, and an intake port 22 of the cylinder head 21 so as to be movable up and down. The intake valve 24 and the exhaust port 23 of the cylinder head 21 can be moved up and down freely. And valves 25, a single cylinder and inclined-cylinder OHC (overhead camshaft) type air-cooled engine to the main structure.

  Reference numeral 26 denotes a ground plane (horizontal plane), and the cylinder block 15 is inclined with respect to the ground plane (horizontal plane).

  The engine body 27 includes a crankcase 13, a cylinder block 15, a cylinder head 21, a crankshaft 14, a connecting rod 18, a piston 17, an intake valve 24, and an exhaust valve 25. The crankcase 13, the cylinder block 15, and the cylinder head. 21 constitutes a casing 28 of the engine body 27, and the cylinder block 15 and the cylinder head 21 constitute a combustion chamber 29.

The crankshaft 14 is also a shaft for taking out power, and a power take-out portion 31 is formed at one end, and the power take-out portion 31 is sometimes called PTO (power take-off).
The cylinder head 21 includes a valve operating chamber 32 for driving the intake valve 24 and the exhaust valve 25 by the rotation of the crankshaft 14. In the figure, 33 is an oil level gauge, 41 is a muffler cover, and 45 is a discharge pipe that is an outlet of exhaust gas attached to the muffler cover 41.

  FIG. 2 is a side view of a general-purpose engine that employs a muffler support structure according to the present invention. The engine 10 includes, in the engine body 27, auxiliary equipment that is an accessory for operating the engine 10, and the main ones. An air cleaner 35 that draws in outside air, a carburetor 36 that vaporizes and sends fuel (gasoline) to the combustion chamber 29 (see FIG. 1), a fuel tank 37 that stores fuel, and a muffler that reduces exhaust noise of exhaust gas. 40 (see FIG. 1), a recoil starter 39 for starting the engine 10, an oil level detection device (oil alert) 50 for detecting the oil level (lubricating oil level), and an ignition unit (not shown) for ignition. And a built-in plug cap 60.

  In the figure, 42 is an oil supply port for supplying oil, 43 is an exhaust pipe having one end extending from the cylinder head 21 and having a muffler 40 attached to the other end, and 44 is a starting knob (grip) of the recoil starter 39.

  FIG. 3 is a rear view of a general-purpose engine employing the muffler support structure according to the present invention. The engine 10 has a generator (not shown) and a cooling unit on the opposite side of the power take-out portion 31 (see FIG. 1) of the crankshaft 14. The fan 47 is attached in this order from the inside, the cooling fan 47 is surrounded by a fan cover 48, and a recoil starter 39 is provided that rotates in mesh with the crankshaft 14 (see FIG. 1) at the time of starting. 49, a main panel 52 is disposed on the upper side of the recoil starter cover 49, and a cover panel 53 is provided between the fuel tank 37 and the recoil starter cover 49 so as to be continuous with the main panel 52. It is.

  The main panel 52 and the cover panel 53 constitute an operation panel. The main panel 52 includes a switch knob 54 as an operation member for setting the engine 10 to an ON state, and a governor motor (see FIG. 2) provided in the carburetor 36 (see FIG. 2). And an adjustment knob 55 as an operation member for adjusting the characteristic (not shown).

  FIG. 4 is a side view showing a mounting state of the muffler support structure for the general-purpose engine according to the present invention. The muffler 40 is connected to the other end of the exhaust pipe 43 in which one end of the exhaust pipe 43 is attached to the exhaust port 23 of the cylinder head 21. At the same time, a support bracket (stay) 81 is extended from the muffler 40 side, and this support bracket 81 is attached to a muffler support portion 82 provided on the cylinder head 21 (engine body 27 side). That is, the muffler 40 is supported at three points on the engine body 27 side by supporting two points on the other end of the exhaust pipe 43 and supporting one point on the muffler support portion 82.

  In order to attach one end to the exhaust port 23, the exhaust pipe 43 forms left and right exhaust port side attachment portions 83, 83 (one 83 is not shown) sandwiching the center of the exhaust pipe 43 at one end. In order to connect the other end, left and right muffler side connecting portions 84 and 84 (one 84 is not shown) are formed at the other end with the center of the exhaust pipe 43 interposed therebetween. In the vicinity of the inlet pipe) 85 side, a bent portion 86 is formed for the exhaust gas to be coaxial with the introduction pipe 85. In the figure, 87 is a stud bolt on the cylinder head 21 side, 88 is a gasket, 89 is a nut screwed into the stud bolt 87, 91 is a stud bolt on the muffler 40 side, 92 is a nut screwed into the stud bolt 91, 118 is a muffler support portion 82 It is a bolt that stops the support bracket.

  In addition, by forming the bent portion 86 in the exhaust pipe 43, it also has the effect of suppressing the vibration of the engine 10.

FIG. 5 is a plan view of an exhaust port of a muffler support structure for a general-purpose engine according to the present invention, and FIG. 6 is a sectional view taken along line 6-6 of FIG.
The exhaust port 23 shown in FIG. 5 has stud bolts (exhaust port side stud bolts) 87 and 87 embedded in order to attach the left and right exhaust port side attachment portions 83 and 83 of the exhaust pipe 43 shown in FIG. In the exhaust pipe 43, the gasket 88 is mounted on the stud bolts 87, 87 to fit the left and right exhaust port side mounting portions 83, 83, and the exhaust port side mounting portions 83, 83 are connected to the nuts 89, 83 from above. It fixes to the exhaust port 23 by 89 (refer FIG. 6).

  As shown in FIG. 4, the extension direction of stud bolts 87 and 87 on the exhaust port 23 side is made different from the extension direction of stud bolts (muffler side stud bolts) 91 and 91 on the muffler 40 side described later. The assembling property or the detaching property of the muffler 40 can be improved.

Next, the structure of the muffler will be described.
FIG. 7 is a side cross-sectional view of a muffler support structure for a general-purpose engine according to the present invention. The muffler 40 is formed on the exhaust pipe 43 side, and a lower housing 94 as a housing constituting the lower portion is formed. An upper housing 93 as a covered housing, an upper partition wall 95 as a partition wall provided in two layers for partitioning these upper and lower housings 93, 94, and a lower partition wall 96 as a partition wall; An introduction pipe (inlet pipe) 85 penetrating the upper and lower housings 93 and 94 and the upper and lower partition walls 95 and 96, and a discharge pipe (outlet pipe) sandwiched between the upper partition wall 95 and the lower partition wall 96 ) 97, a sound absorbing material (glass wool) 98 for absorbing sound energy interposed between the upper and lower partition walls 95, 96 and the discharge pipe 97, and a lower housing. A reinforcing plate 99 for reinforcing the ring 94, constituting a.

  Further, in the muffler 40, a first silencing chamber 101 as a silencing chamber is formed by the lower housing 94 and the lower partition wall 96, and a second silencing chamber 102 as a silencing chamber is formed by the upper housing 93 and the upper partition wall 95. And the upper partition wall 95 and the lower partition wall 96 form the third sound deadening chamber 103 as a sound deadening chamber, and the upper partition wall 95 and the lower partition wall 96 store the sound absorbing material 98. The material storage portion 104 is formed. In the figure, reference numeral 105 denotes the bottom surface of the muffler 40.

  The introduction pipe 85 has an introduction pipe opening 106 as an opening opened at one end to connect to the exhaust pipe 43, a lid member 107 provided at the other end to close the other end, and an exhaust gas through the introduction pipe 85. A plurality of introduction pipe side gas holes 108 (... indicate a plurality, the same shall apply hereinafter) provided near one end (exhaust pipe 43 side) to lead to the first muffler chamber 101. .

  The lower housing 94 is inclined with respect to the ground surface (horizontal plane) 26 shown in FIG. 1 and is formed on the inclined surface 111 so as to be fitted (caulked) to the introduction pipe opening 106 of the introduction pipe 85. A mating port 112, a stud bolt 91 for mounting the exhaust pipe 43 by being formed around the mating port 112, a support bracket 81 shown above to be attached to the muffler support portion 82 (see FIG. 4) of the cylinder head 21, Is provided. In the figure, 117 is a bolt through hole formed in the support bracket 81.

  The upper housing 93 includes a caulking portion 114 that integrally fixes the lower housing 94 and the upper and lower partition walls 95 and 96 to the outer periphery, and the other end of the introduction pipe when one end of the introduction pipe 85 is the exhaust pipe 43 side. An upper housing hole 115 that allows the (cover member 107) to face the outside, and a stopper 116 for stopping the muffler cover 41 are provided.

  FIG. 8 is a plan view of a muffler support structure for a general-purpose engine according to the present invention. The exhaust pipe 43 has left and right sides sandwiching the center of the exhaust pipe 43 at one end in order to attach one end to the exhaust port 23 (see FIG. 5). The left and right muffler side connecting portions 84 are formed at the other end with the center of the exhaust pipe 43 interposed therebetween in order to form the exhaust port side mounting portions 83 and 83 and to connect the other end to the muffler 40. The muffler 40 is provided with a support bracket 81 attached to the muffler support portion 82 on the cylinder head 21 side.

  Therefore, it can be said that the muffler 40 can be supported by the left and right exhaust port side mounting portions 83 and 83 and the muffler support portion 82 in plan view. It can be said that the left and right exhaust port side mounting portions 83 and 83 and the muffler support portion 82 are arranged so that the center of gravity G1 of the muffler 40 is positioned in the triangle connecting the portions 82. Thereby, the muffler 40 can be stably supported.

  In other words, the muffler support structure 80 for the general-purpose engine is configured such that one end of the exhaust pipe 43 is connected to the exhaust port 23 of the engine 10 and the muffler 40 is attached to the other end of the exhaust pipe 43. In order to attach one end to the exhaust port 23, the left and right exhaust port side attachment portions 83, 83 are formed on one end with the center of the exhaust pipe 43 interposed therebetween, and the other end is connected to the muffler 40. Left and right muffler side connecting portions 84 and 84 are formed at the end with the center of the exhaust pipe 43 interposed therebetween, and a muffler support portion 82 that supports the muffler 40 is formed on the engine 10 (cylinder head 21) side shown in FIG. In plan view, the left and right exhaust port side mounting portions 8 are arranged such that the center of gravity G1 of the muffler 40 is positioned in a triangle connecting the left and right exhaust port side mounting portions 83, 83 and the muffler support portion 82. It is obtained by placing 83 and the muffler support portion 82.

  The muffler support structure 80 of the general-purpose engine is such that the left and right muffler side connecting portions 84 and 84 are offset to the outside of the triangle, and the left and right muffler side connecting portions 84 and 84 are offset to the outside of the triangle. Further, it is possible to prevent the muffler from shaking. As a result, it is possible to further reduce the muffler 40 vibration.

Moreover, the muffler support structure 80 of the general-purpose engine is integrally provided with a support bracket 81 that is attached to the muffler support portion 82 on the muffler 40.
Since the muffler 40 is integrally provided with the support bracket 81 attached to the muffler support portion 82, an increase in the weight of the engine 10 (see FIG. 4) can be minimized in order to efficiently support the muffler 40. it can. As a result, the weight of the engine can be reduced as compared with, for example, a case where the exhaust pipe is cantilevered and the rigidity of the exhaust pipe is improved.

  FIG. 9 is a bottom view of the lower partition wall of the muffler support structure for a general-purpose engine according to the present invention. The lower partition wall 96 extends from the first silencing chamber 101 (see FIG. 7) to the second silencing chamber 102. A gas hole 121 through which exhaust gas is introduced, a through hole 122 through which the introduction pipe 85 passes, and a lower part of the third silencing chamber 103 shown in FIG. It is a plate provided with a bulging portion 123 and a lower concave portion 124 that houses a discharge pipe (exit pipe) 97 and a sound absorbing material 98. Since FIG. 9 is a bottom view of the lower partition wall 96, the lower bulging portion 123 and the lower concave portion 124 are displayed as convex surfaces.

  FIG. 10 is a plan view of the upper partition wall of the muffler support structure for a general-purpose engine according to the present invention. The upper partition wall 95 opens the gas holes 121... Of the lower partition wall 96 shown in FIG. A longitudinal opening 126 and a substantially rectangular opening 127 that form an opening), an upper bulging portion 129 that forms an upper portion of the through-hole 128 that penetrates the introduction pipe 85 shown in FIG. From the second muffler chamber 102 (see FIG. 7) by opening the tube (exit tube) 97 and the upper recess 131 for storing the sound absorbing material 98 and opening the upper bulged portion 129 to the third muffler chamber 103 side. And a gas hole 132 for introducing exhaust gas into the third silencing chamber.

  In addition, since FIG. 10 is a top view of the upper partition wall 96, the upper bulging part 129 and the upper recessed part 131 are displayed as a convex surface. Further, the third silencing chamber 103 shown in FIG. 7 includes an upper bulging portion 129 and a lower bulging portion 123 (see FIG. 9), and the sound absorbing material storage portion 104 shown in FIG. The concave portion 124 (see FIG. 9) is used.

FIG. 11 is a front sectional view of a muffler support structure for a general-purpose engine according to the present invention. A discharge pipe (exit pipe) 97 is closed by applying one end to the third muffler chamber 103 and the other end (open port 135). ) Open to the outside and communicates with a gas hole group 133 formed at one end for introducing exhaust gas from the third silencing chamber 103 and a sound absorbing material (glass wool) 98 stored in the sound absorbing material storing portion 104. And a communication hole group 134 formed near the other end to absorb sound energy.
The stud bolts 91, 91 are penetrated through the reinforcing plate 99 and the lower housing 94 and protrude outward from the lower housing 94.

FIG. 12 is a perspective view of a muffler support structure for a general-purpose engine according to the present invention, and shows the flow of exhaust gas.
Exhaust gas is caused to flow from the exhaust pipe 43 (see FIG. 7) into the inlet pipe opening (one end) 106 as indicated by a broken line arrow a1, and the exhaust gas flowing into the inlet pipe 85 is supplied to the lid member (other end) 107 of the inlet pipe 85. Hit it.
At this time, since the lid member 107 faces the outside from the upper housing (housing) 93, the exhaust gas can be cooled when the exhaust gas is applied to the lid member 107.

  The exhaust gas whose temperature has been lowered in advance is U-turned by the lid member 107 as indicated by a broken line arrow a2, and flows into the first muffler chamber 101 from the introduction pipe side gas holes 108 as indicated by broken line arrows a3 and a3. In order to cause the exhaust gas in the introduction pipe 85 to flow as indicated by the broken arrow a1 to the arrow a2, the exhaust pipe 43 (see FIG. 7) is coaxial with the introduction pipe 85 in the vicinity of the introduction pipe 85 side of the muffler 40. The bent portion 86 was formed.

  After exhausting the exhaust gas in the first silencing chamber 101 as indicated by broken arrows a4 and a4 and broken arrows a5 and a5, the exhaust gas is passed through the gas holes 121... As indicated by arrows a6 and a6 and arrows a7 and a7. As shown in FIG.

  Next, exhaust gas flows from the second silencing chamber 102 into the third silencing chamber 103 as indicated by arrows a8 and a8 and arrows a9 and a9.

  Then, the third silencer 103 is caused to flow into the discharge pipe 97 as indicated by broken line arrows a10 and 10, and the exhaust gas is caused to flow into the discharge pipe 97 as indicated by broken line arrows a11. The glass wool 98 is flown as indicated by the broken arrow a12. Then, exhaust gas sufficiently cooled and silenced is discharged from the discharge pipe 97 to the outside as indicated by arrows a13 and a13.

  FIG. 13 is a comparative view of a muffler support structure of a general-purpose engine according to the present invention. FIG. 13A is a side view of a muffler support structure 230 of a general-purpose engine of a comparative example, and FIG. The rear view of the muffler support structure 80 is shown.

  In (a), the muffler support structure 230 of the general-purpose engine is such that an exhaust pipe 232 is extended from a cylinder head 231 and a muffler 233 is attached to the tip of the exhaust pipe 232. Since the muffler 233 having a large volume with respect to the diameter of the exhaust pipe 232 is supported, the muffler 233 may swing as indicated by an arrow b1 or an arrow b2. G3 indicates the position of the center of gravity of the muffler 233.

  In (b), in the muffler support structure 80 of the general-purpose engine, the center of gravity G1 of the muffler 40 is positioned in a triangle connecting the left and right exhaust port side attachment portions 83 and 83 and the muffler support portion 82 in plan view. By arranging the left and right exhaust port side mounting portions 83 and 83 and the muffler support portion 82, the muffler 40 can be supported at three points surrounding the center of gravity G1. As a result, the vibration of the muffler 40 can be reduced, and the noise generated from the muffler 40 can be reduced.

FIG. 14 is a plan view of a muffler support structure for a general-purpose engine according to another embodiment of the present invention.
The same parts as those used in the muffler support structure 80 (see FIG. 8) of the general-purpose engine are denoted by the same reference numerals, and detailed description thereof is omitted.
In the figure, 43 is an exhaust pipe, 83 and 83 are left and right exhaust port side mounting portions formed at one end of the exhaust pipe, 84 and 84 are left and right muffler side connecting portions formed at the other end of the exhaust pipe, and 212 is an engine 200. A muffler support portion 211 formed on the side is a support bracket of the muffler 210. The engine 200 is an engine having substantially the same configuration as the engine 10 shown in FIG. 1, and the muffler 210 is a muffler having substantially the same configuration as the muffler 40 shown in FIG.

  In the muffler support structure 220 of the general-purpose engine, the left and right exhaust port side mounting portions 83 and 83 are arranged at symmetrical positions with respect to the center of the other end of the exhaust pipe 43, and the left and right exhaust port side mounting portions 83 and 83 are arranged. By forming the muffler support portion 212 at the apex of the isosceles triangle having the connecting line as the base, the isosceles triangle connecting the left and right exhaust port side attachment portions 83 and 83 and the muffler support portion 82 in a plan view. The left and right exhaust port side attachment portions 83 and 83 and the muffler support portion 82 are arranged so that the center of gravity G2 of the muffler 40 is located inside. Therefore, the weight G2 of the muffler 210 can be apportioned by the left and right exhaust port side attachment portions 83, 83 and the muffler support portion 212.

  The muffler support structure of the general-purpose engine according to the present invention is such that the center of gravity of the muffler 40 is located in a triangle connecting the left and right exhaust port side mounting portions 83 and 83 and the muffler support portion 82 as shown in FIG. However, the present invention is not limited to this, and does not preclude providing a support portion that supports the muffler in an auxiliary manner.

  As shown in FIG. 7, the muffler support structure for a general-purpose engine according to the present invention has a muffler 40 as an introduction pipe, first to third silencing chambers 101 to 103, and a discharge pipe (outlet pipe) 97 as main components. However, the present invention is not limited to this, and the internal structure of the muffler is arbitrary, as long as the center of gravity of the muffler is located in a triangle connecting the left and right exhaust port side mounting parts and the muffler support part. .

  The muffler support structure for a general-purpose engine according to the present invention is suitable for use in a small air-cooled engine or an automobile engine.

1 is a front view of a general-purpose engine that employs a muffler support structure according to the present invention. 1 is a side view of a general-purpose engine that employs a muffler support structure according to the present invention. It is a rear view of the general purpose engine which adopted the muffler support structure concerning the present invention. It is a side view which shows the attachment state of the muffler support structure of the general purpose engine which concerns on this invention. It is a top view of the exhaust port of the muffler support structure of the general purpose engine which concerns on this invention. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is side surface sectional drawing of the muffler support structure of the general purpose engine which concerns on this invention. It is a top view of the muffler support structure of the general purpose engine which concerns on this invention. It is a bottom view of the partition wall under the muffler support structure of the general purpose engine which concerns on this invention. It is a top view of the partition wall on the muffler support structure of the general purpose engine which concerns on this invention. It is front sectional drawing of the muffler support structure of the general purpose engine which concerns on this invention. 1 is a perspective view of a muffler support structure for a general-purpose engine according to the present invention. It is a comparative examination figure of the muffler support structure of the general purpose engine concerning the present invention. It is a top view of the muffler support structure of the general purpose engine of another embodiment concerning the present invention. It is a figure explaining the conventional basic composition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Engine, 23 ... Exhaust port, 40 ... Muffler, 43 ... Exhaust pipe, 80 ... General-purpose engine muffler support structure, 81 ... Support bracket, 82 ... Muffler support part, 83, 83 ... Left and right exhaust port side attachment part, 84, 84 ... left and right muffler side connecting portions, 85 ... introduction pipe, 93, 94 ... housing (upper / lower housing), 97 ... discharge pipe (outlet pipe).

Claims (4)

In the muffler support structure of a general-purpose engine in which one end of the exhaust pipe is connected to the exhaust port of the engine and a muffler is attached to the other end of the exhaust pipe.
In order to attach one end of the exhaust pipe to the exhaust port, the left and right exhaust port side mounting portions are formed at the one end with the center of the exhaust pipe interposed therebetween, and the other end is connected to the muffler. Form the left and right muffler side connecting parts across the center of the exhaust pipe at the end,
A muffler support part for supporting the muffler is formed on the engine side,
The left and right exhaust port side mounting portions and the muffler support portion are arranged so that the center of gravity of the muffler is positioned in a triangle connecting the left and right exhaust port side mounting portions and the muffler support portion in plan view. A muffler support structure for general-purpose engines.   The muffler support structure for a general-purpose engine according to claim 1, wherein the left and right muffler side connecting portions are offset to the outside of the triangle.   The left and right exhaust port side mounting portions are arranged at symmetrical positions with respect to the center of the other end of the exhaust pipe, and a vertex of an isosceles triangle having a line segment connecting the left and right exhaust port side mounting portions as a base The muffler support structure for a general-purpose engine according to claim 1, wherein the muffler support portion is formed in the main engine. The muffler support structure for a general-purpose engine according to claim 1, wherein a support bracket attached to the muffler support portion is integrally provided on the muffler.

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