JPS5840651B2 - Internal combustion engine with noise reduction canopy - Google Patents

Description

[Detailed Description of the Invention] This invention provides the following (A, (B), (T)), that is,
(a) It consists of a plurality of members that constitute a cover, which are installed soundproofingly at a distance from the internal combustion engine main body, and which are at least partially fixed to the engine main body in such a way as to block sound conducted by the solid floor. Piping and other connecting parts are configured to pass through it in a sealing manner, and (a) its bottom member is designed to sandwich the internal combustion engine body from below in a U-shape, and passes through the crankshaft axis. It is tall enough to rise above the horizontal plane, and is suspended from the engine body through a member that blocks sound conduction from the solid floor, and is equipped with a penetration part necessary for holding the engine body. (a) a sound-attenuating cover meeting the following characteristics: (1) all penetrations provided therein are provided with connections adapted to receive elastic seals; This applies to an internal combustion engine having a similar configuration.

It is already known to cover engines, especially internal combustion engines, with sound-attenuating sheaths.

In many such cases, good noise reduction is achieved by applying sound absorbing material to the covering, at least in part.

However, with such a configuration, the weight is heavy, the manufacturing cost is high, and it is difficult to modify the engine body covered by it.

Additionally, heat exchange between the engine itself and the external environment is often impeded.

The engine canopy modification known from Austrian Patent No. 308,475 makes use of the laws of acoustic physics to achieve good noise reduction without the specific addition of such sound-damping materials.

That is, in the known configuration, the cover is directly fixed to the engine body while blocking the sound conducted by the solid floor, and the installed pipes and other engine body connection parts are led out through the first group cover part. , and a second group cover portion fixed to the first group cover portion in a sealing manner but so as to be easily removable.

These first group cover parts are used for the oil sump part of the engine body, the cylinder head part, and even partially the cylinder outer wall,
They are fixed at various points on the solid floor through members that block sound conduction from the solid floor.

With this configuration, good noise reduction can certainly be achieved, and the easily removable second group cover allows
Although it is easy to modify the engine body covered in this way for adjustment and maintenance, the difficulty that is particularly noticeable when the machine body covered in this way is built into a vehicle is that it is difficult to modify it. The ease of use is still considerably exacerbated by the parts that are attached to the fuselage.

The manufacturing and assembly costs are high because a significant number of solid floor sound-intercepting elements are required.

Furthermore, the solid-conducted sound reduction effect is adversely affected to some extent by each such additional connection between the sound source (engine) and the canopy.

Completely removing obstructions from the upper part of the crankshaft center of an engine installed in a vehicle would either increase assembly costs or be impossible in the first place.

Furthermore, Federal Republic of Germany Patent Application Publication No. 224131
In what is known in specification No. 4, the canopy bottom member is suspended from the internal combustion engine via a member that blocks sound conduction from the solid floor, and is necessary for holding the engine body. It is provided with a penetration through which the

The canopy bottom member is complemented upwardly by two annular intermediate members enclosing the engine, which form a horizontal separator fixed to the internal combustion engine in such a way as to block solid floor sound conduction. are fixed together by.

Other than the one large cover on the top, there are no other covers for adjustment or maintenance.

Therefore, this configuration does not mean that all parts that require adjustment and maintenance can be easily touched, and the dependent claims of the published specification include that the bottom and top parts of the cover may be made into one piece. However, since there is also a description that a multi-member structure preferably welded together may be used, it seems that such a structure was not even originally intended.

An object of the present invention is to provide a sound-attenuating canopy with excellent acoustic effects that eliminates the above-mentioned drawbacks of conventional constructions.

This novel design should also easily allow noise reduction of torque converters or transmissions connected to the internal combustion engine, if required.

In order to solve this problem, this invention has the following characteristics (a)
, (b), (c), and (d).

(a) Of all the penetrations required for the operation of the engine, as many as possible are incorporated into the canopy bottom member.

(b) The upper member to be covered is configured to sandwich the internal combustion engine main body from above in a U-shape, and is fixed only to the connecting flange of the bottom member,
Of all the penetrations required for the operation of this engine, those other than the bottom member are incorporated into this.

(c) There are hollow parts in both the upper and bottom parts of the cover, and these parts are used for sealing purposes.
At least the parts of the internal combustion engine that require adjustment and maintenance are covered by an assembled cover that can be easily removed.

(d) The canopy in tubular form made up of both the top and bottom parts of the internal combustion engine is further provided with at least one penetration on either side of the front end and the output end of the internal combustion engine. closure member, sealingly closed.

With this covering structure, it is possible to modify the covered equipment very easily under almost any installation conditions.

Since this upper cover member is not fixed anywhere on the engine body, it can be easily removed even in the case of an installed engine.

There are gouges in both the top and bottom parts of the cover, so when adjusting, maintaining, or making minor repairs to the engine, you can easily move it by simply removing the easily removable cover.

This overall covering reduces manufacturing and assembly costs because there are fewer members that block solid floor sound conduction, and the noise blocking effect is improved.

As a characteristic example of the present invention, a rotation speed and/or torque converter directly flanged to the engine body;
There are internal combustion engines which are characterized in that the cover also encloses such a converter.

According to this configuration. The gear shift noise itself is often quite noisy.

Furthermore, with this simple method, noise transmitted from the internal combustion engine itself to the transmission and torque transmission can be effectively suppressed so that it does not radiate to the surroundings.

Another embodiment of the present invention is an internal combustion engine equipped with a transmission flanged directly to the clutch, which has the following characteristics (7) and (a), namely (a) a canopy closing portion on the output end side; However, the transmission cover main body material is separate from the internal combustion engine main body cover, and is suspended from the transmission cover so that the gearbox is sandwiched in a U-shape from below and solid conduction sound is blocked. and a cover fixed thereto to close the upper side of the transmission cover; are provided, the gap of which is bridged in a sealing manner by a sleeve, preferably constructed as an elastic rubber band.

There is something that satisfies both of these.

This arrangement effectively attenuates such noise sources and at the same time eases the assembly process, particularly in the case of large transmissions as a preferred application.

Separating the canopies also prevents mutual influence from one of the canopies to the other, such as noise conduction.

The surrounding noise emitting dust is a function of the noise emitting area, and dividing the noise into small area portions has advantageous results from this relationship as well.

In the case of an internal combustion engine with a torque transducer flanged directly on the engine body, the canopy closure member on the side of the output end is constructed in two parts, and the abutting surfaces of the two parts fit into the output shaft through hole. One configured to pass through the center is also preferred.

Since such converters are generally of short construction, they can be accommodated within the internal combustion engine canopy.

Since the closing member at the end of the converter has a two-part structure, when it is necessary to disassemble it, it is easy to modify the converter itself and the output shaft connected to it. .

As an embodiment of the present invention which can also be modified easily, the canopy closing member on the front end side of the engine is constructed in two parts, and the abutting surfaces of these two parts preferably form the part through the canopy hole. a substantially horizontal plane passing through the center, and further comprising a bottom cutout in the canopy bottom member being closed by an easily removable cover adapted to conform to the shape of the sump. There are also internal combustion engines with different configurations.

In either of these configurations, a large portion of the internal combustion engine surface becomes freely accessible by simply loosening the easy-to-remove assembly to remove each closure member.

As a more characteristic example of this invention, the following characteristics (
7), (a), that is, (7) A cover in which the large cutout holes on both left and right sides in the longitudinal direction of the engine body are substantially horizontally divided into a plurality of parts, preferably two. (a) Where the divided parts are adjacent to each other, the span members for abutting part of the cover are removably assembled to the upper part of the cover. There is an internal combustion engine.

With this configuration, both sides of the engine can be exposed almost completely with a simple operation, even if the running gear gets in the way, reducing work time for adjustments, maintenance, and repairs. Not only can you save a lot of money, but it also makes these tasks easier.

A further characteristic embodiment of the present invention is an internal combustion engine in which the engine is held through an elastic material that blocks solid conduction sound, and has the following characteristics (7) and (a).

(7) Those members that block solid-conducted sound are assembled inside the can on both the engine body and the engine body support stand which is also pulled out from the can. (b) Such a support is fixedly held on the vehicle chassis (of course, by means of an ejector tube provided in the bottom member);
There is one that satisfies all of these requirements, with rubber sleeves installed to prevent noise from escaping through the air between the engine body support stand and the support stand.

This configuration eliminates the possibility of solid conduction sound being extracted from the canopy via the engine body support, and this problem, which has been considered a difficult problem with engine canopies, can be solved very effectively. be.

The structure in which the internal combustion engine main body support stand is constructed as an integral layered member and supports the engine main body from below allows the load on the elastic members to be dispersed without difficulty.
Very preferable.

In another example that further advances this invention idea, such an engine body support stand is said to be directly connected to the engine body, and the member for blocking solid conduction sound is assembled to the vehicle chassis outside the canopy. There is a structure in which the seal between the cover and the solid-conducted sound blocking member is to be achieved by a diaphragm-type sleeve material or a lip-type sealant. .

According to this configuration, when it becomes necessary to remove the engine body or the entire equipment, the entire equipment can be removed from the car body by simply loosening a few screws that can be accessed from the outside. The convenience of being able to leave is realized.

As a recently described characteristic example of the present invention, a configuration in which a member for blocking solid conduction sound is assembled to a vehicle chassis via a bracket is also preferable.

This is particularly suitable for heavy-duty applications.

The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings.

The canopy according to the present invention has two main components, namely, a canopy bottom member 1 and an upper part 2.
That is.

Together, they enclose the internal combustion engine main body 3 and the torque converter 4 (Fig. 3) and rotational speed converter (i.e., transmission) 5, if any, installed therein. I'm here.

As shown in FIG. 1, the transmission 5 may include a dedicated cover, ie, a transmission casing 6, separate from the internal combustion engine main body cover.

The cover bottom member 1 is arranged in a U-shape from the bottom to the internal combustion engine main body 3.
(Fig. 1) A drive unit 3' (Figs. 3 and 4) consisting of an internal combustion engine main body 3 and a torque converter 4 is sandwiched between them, and the edge 7 of this cover bottom member 1 is configured as a flange. The through holes 9 and 10 for the unit holding parts 11 and 12, which protrude to a higher level than the horizontal plane passing through the crankshaft axis center 8 and are designed to block at least solid-conducted sound, are located in this cover bottom member. 1.

The cover bottom member 1 is further provided with through holes 13 and 14 for introducing cooling water, conduits for pressure fluid, air, fuel, and electricity, and for control adjustment.

This canopy bottom member 1 is suspended from the internal combustion engine body 3 or unit 3' by means of preferably four solid-conducted sound-blocking elastic members 15 (FIG. 4).

If such an internal combustion engine body or unit is built into a vehicle, this bottom member cannot be removed.

The upper cover member 2 is also configured in a U-shape.

This is placed over the internal combustion engine main body 3 or unit 3' from above.

Unlike the canopy bottom part 1, this canopy top part 2 is not fixed to any part of the unit 3' (FIG. 4), but only to the flange 7 of the canopy bottom part 1, already mentioned. and its flange is for this purpose.

This canopy upper member incorporates all the penetration parts necessary for engine operation other than the bottom part, and the most noticeable ones are the cooling water outlet 16.
There are through holes for an intake pipe 17 and an exhaust pipe 18.

However, in principle these through holes could also be integrated into the canopy and bottom part.

Of course, although not shown in detail in the drawings, if there are other penetrations that cannot be incorporated into the canopy bottom member 1, they can be incorporated into the canopy top member 2.

In any case, each penetration is provided with a connection designed to accommodate a sealant, in order to prevent this airborne sound from being produced.

For that purpose, all penetrations other than those for exhaust pipes are
A large number of circular protruding pipe parts 19 to 25 are assembled, each of which has one end of a rubber spring 26 to 29 fixed, and the other end of the rubber bush 26 to 29 fixed to a penetrating member at that location. I am doing what I want to do.

Since such a sealing method cannot be used in hot or rotating parts, the exhaust pipe 18 and the drive shaft 31 are both enclosed in protruding pipes 33 and 34 lined with sound-absorbing material 32 and bowed from the canopy. I'm trying to be served.

In the case of a drive unit with a transmission 5 flanged to the internal combustion engine body 3, as shown in FIG. It can also be taken as a thing.

This casing is also provided with a cover 35 that sandwiches the transmission 5 from below in a U-shape, and is suspended from the transmission via an elastic member 36 that also blocks solid-conducted sound. , cover its upper side 3
7 is closed, its cover and this canopy 35.

Together, they are intended to create, on the side facing the internal combustion engine body 3, a protruding pipe 38 for connecting the comb shaft and spring 39.

There is an axial clearance between this transmission cover 35 and the internal combustion engine main body cover.

The gap is bridged by the rubber bridge 39 mentioned above.

However, as another form, the transmission casing 6 may have its connecting protruding pipe 38 protruded into the internal combustion engine main body casing as far as it remains in the radial direction, and the annular gap created there may be covered with a suitable elastic sealing material. You can also think of things you want to include.

Furthermore, it is also possible to connect the transmission casing to the internal combustion engine main body cover in a manner that is solid and immovable, but is removable.

Towards the output end side, this transmission casing 6 has a cover 40
The cover, which can also be of two-part construction, is provided with the penetration 33 for the output shaft 31 already mentioned.

In the canopy bottom part 1, close to the oil sump 41, there is a gouged hole 42 adapted to the dimensions of the oil sump,
It is sealed closed by an easily removable cover 43 that follows the shape of the oil sump 41.

Therefore, it is possible to easily modify the oil sump 41 for oil change or removal of the oil sump.

The cover upper member 2 also has a gouge hole in the upper part of the engine, which is made as large as possible, and a cover 44 that can be easily removed.
It is sealed and closed by.

There are large gouge holes on both longitudinal sides of the internal combustion engine main body 3 and the unit 3', preferably near the internal combustion engine main body, and also on the front end surface, extending over both the bottom and top members 1 and 2, respectively, They also cover 45.46
covered with

Both covers are held by a quickly operable closure not shown in detail and include a suitably shaped seal 46' (FIG. 4) along the lip.

The cover 46 on the front end surface of the internal combustion engine is different from the others because it also includes a through hole 25 for the ventilation fan of the internal combustion engine 3.

In addition, in the embodiment shown in FIG. 3, the ventilation fan 47
The cover 48 in this case is also of a slightly different shape since it is bearing inside the cover.

In any case, the front end cover, whether it is the one shown in Figure 1 or the one shown in Figure 3, can be of split construction so that it can be easily removed, in which case it is generally possible to The abutting surface is a horizontal plane passing through the center of the ventilator penetration.

In the embodiments shown in FIGS. 3 to 5, the side cover 45 is composed of two parts 45' and 45''.

This configuration is absolutely necessary when the cover 45 is very large and it would be difficult or impossible to remove it as it would interfere with the traveling mechanism frame support stand. .

In the case of such a two-part structure of the cover 45, it is necessary to provide a liquid-conducting span member 49 which is removably fixed to the cover upper member 2 (FIG. 4).

After removing the covers 45' and 45'', remove the connecting material 4.
9 can also be removed to easily modify the internal combustion engine main unit.

The embodiment of the cover shown in FIGS. 3 to 5 is for a unit consisting of an internal combustion engine main body 3 and a torque converter 4.

Since such a converter 4 is made short, it can be housed inside the canopy of the internal combustion engine body 3.

In this case, the closing member on the side of the output end consists of two covers 50, 5, which are in a split configuration and overlapping each other.
0', and when the two force bars are in the assembled state, the protruding tube portion 5 is also circular.
1, and its protruding tube portion has a sealing sleeve 52. in the shape of a rubber band or rose. That is, the entire unit cover is sealed against the transmission 53 which is assembled after the converter 4.

In addition, 43' in the figure is a cover of the lower protruding bottom of the torque converter 4.

FIG. 6 shows a preferred method for holding the internal combustion engine main body 3 and the drive unit 3' on the vehicle chassis 54.

A layered transverse support 55 passes under the entire unit, and the unit is connected to this transverse support 55 via a solid-conducted sound blocking member 56.

This horizontal support stand 55 itself is fixed to the vehicle chassis 54 with screws.

Rubber bolts 57 are installed at all locations where this horizontal support base penetrates the cover bottom member 1 in order to prevent airborne sounds from being produced.
In each case, one end is fixed to a short protruding tube 57' from the canopy, and the other end is fixed to the horizontal support base 55, respectively.

In the embodiment shown in FIG. 7, the metal members 58 and 59 at both ends included in the component of the member 11 that blocks solid conduction sound are
It is configured to act as a stop that prevents too severe elastic deformation.

Since these art materials constructed in this way are themselves a source of large noise, they must be incorporated inside the canopy.

For this reason, the ;= member is provided with means for fixing the rubber sleeve 29 surrounding the member 11 on the chassis side.

Such a means can be realized by a simple method of interposing a thin sheet metal member 61 between the bracket 62 on the chassis side and this member 11 with screws.

FIG. 8 shows an example in which the lip type sealing material 63 is substituted for the joints and rosettes as just described, and the sealing material is fixed to the closing member 76 and is made of sheet metal as already described. They cooperate so as to butt against the member 61.

A member 65 for blocking solid conduction sound and an internal combustion engine main body 3,
A support base 68 is interposed between the unit 3' and the unit 3'.

The main advantage of this configuration is that since the sealant is not fixed on the chassis side, there is no need to loosen or remove screws or other fixed members when removing the entire unit, which saves work time. This has the great advantage of not only requiring a short length of screw, but also eliminating the space occupied by the screw.

A cut-out hole 67 with a rubber cap 66 is provided in order to be able to access the interior of the cover in order to loosen the screw 64 securing the previously mentioned member 65.

The elastic member 69 used in the embodiment shown in FIG.
An end metal material 70 on the engine side included in the component,
Although it receives solid conduction sound from the unit as it is, it is vulcanized so that it is deeply inserted into the rubber material 71 to serve as its core material, and only radiates a very small amount of noise.

Therefore, this may be provided outside the canopy 1.

In order to suppress airborne sounds, here a diaphragm-type rubber sleeve 72 is used, which is connected at one end to the connection 73 of the covering bottom part 1 and at the other end to the support base 75.
The intermediate member 74 interposed between the member 69 and the member 69 is fixed to the member 69 itself.

As a holding system for the internal combustion engine main body 3 or the disturbance unit 3', the front end, output end, and each side may be unified into one of the same forms shown in FIGS. 6 to 9, or Any one of the configurations shown in FIGS. 7 to 9 and the configuration shown in FIG. 6 may be combined.

[Brief explanation of the drawing]

Fig. 1 is a side view of one embodiment of this invention, Fig. 2 is a front view indicated by the arrow ■ in Fig. 1, Fig. 3 is a side view of another embodiment, and Fig. 4 is a side view of an embodiment of this invention. 3 is a cross-sectional view of the drive unit and the canopy taken along the TV-TV line in FIG. Figures 7 to 9 are diagrams showing a partial cross section of the holding part, and each of Figures 7 to 9 is an enlarged view of a partial cross section of another example of the body holding method, and the same members are indicated by the same numbers. There is. 1...Cover bottom member, 2...Cover upper member, 3...Internal combustion engine body, 3'...
... A drive unit consisting of a main body 3 and a converter 4, 4...
...Torque converter, 5...Transmission, 6...
. . . the cover closing part on the side of the output end, for example the transmission casing, 7 . . . the connecting flange of part 1,
8...Crankshaft center, 9,10...
Each through-hole of the cover for the holding part 11.12, 11°12...
...A holding part designed to block solid conduction sound,
13...Cover through hole for introducing cooling water, 14.
......Cover through hole for pressure fluid, pressure air, fuel, electricity conduit or control adjustment, 15...Member that blocks solid conduction sound, 16...Cooling water Exit, 17.
...Intake pipe, 18...Exhaust pipe, 19,2
0,21゜22, 23, 25... Protrusion tube for connecting the roses 26 to 29, 26 to 29...
・Comm jiyabara, 31...Output shaft, 32...
... Sound attenuation material, 33 ... Protruding pipe surrounding the shaft 31, 34 - ... Protruding pipe surrounding the pipe 1B, 35
...Transmission cover body material, 36...Member that blocks solid conduction sound, 37...Body material 35
Upper cover 38... Sleeve 39 connection protruding pipe, 39... Sleeve of which a preferred example is a comb joint and a rose, 40... Output end side cover closing member , 41...Oil sump, 42...Drilled hole in member 1 suitable for oil sump 41, 43...
...Cover covering the hole 42 around the oil sump 41, 43'
...Torque converter 4 lower protruding bottom cover 44
・・・・・・A cover covering the upper hollow hole of member 2,
45...Cover of the hollowed-out portion of the side surface in the longitudinal direction of the engine, 45'. 45"... Upper and lower hook portions of the three-part cover 45, 46...Cover of the front end side cover cut-out part 46'......The cover cut-out hole, ＼ 4T... Ventilator, 48... Engine front end face cover through which the ventilator 47 bearing in the cover passes, 49... Both covers Part 45', 45"
Liquid passing member, 50° 50'... Output end side canopy closing member upper and lower hook halves, 51... Assembling closing member 50, protruding pipe from 50', 52
・・・・・・Sleeve with rubber jiyayabara as a suitable example, 5
3...Transmission, 54...Vehicle chassis, 55...Engine body 3 support stand, 56...
・Member for blocking solid-conducted sound, 57...Sealing sleeve with rubber sleeves and roses as preferred examples, 57'...
・Ejected tubes with sleeves 57 and \ attached to member 1, 58, 59... Collaborative metal members 61 configured to serve as stoppers to prevent severe elastic deformation.
... Thin sheet metal member, 62, 62'... Member 1
1,69 Each assembly includes a bracket, 63...lip type sealing material, 64...screw for fixing member 65, 65...solid conduction sound. blocking member,
66...Rubber cover for hole 67, 67...
Hollow hole, 68...Engine body 3 support base, 6
9... Member that blocks solid conduction sound, 70... ...Metal core material for engine side connection of member 69, 71...
... Rubber material, 72 ... Diaphragm type sleeve material, 73 ... Connection part of member 1 to sleeve material 72, 74 ... Member 69 and base material Intermediate material interposed between 75, 75... engine main body 3 support base, 76... closing member.

Claims (1)

[Claims] 1. The following (7), (a), ('7), that is, (7)
) installed in a soundproof manner at a distance from the internal combustion engine body,
It consists of a plurality of cover components that are at least partially fixed to the engine body in a manner that blocks solid conduction sound, and pipes and other connecting parts are configured to pass through it in a sound-sealing manner. (a) The bottom member is designed to fit into the internal combustion engine body from below in a U-shape, and has a height that rises above the horizontal plane passing through the crankshaft axis, and is a member that blocks solid-conducted sound. It is said to be suspended from the main body of the engine. It is configured to include the penetrations necessary for holding the engine body, and (1) all of the penetrations provided therein have connections designed to receive elastic sealing materials. It is equipped with a sound attenuation cover that satisfies the following characteristics, and also has the following characteristics (a), (b), (
An internal combustion engine characterized by satisfying all of c) and (d). (a) Of all the penetrations required for the operation of the engine, as many as possible are incorporated into the canopy and bottom member 1; (b) The upper member 2 that is to form the cover is designed to sandwich the internal combustion engine main body 3 in a U-shape from above,
It is configured to be fixed only to the connecting flange 7 of the bottom member 1, and of all the penetration parts required for the operation of this engine, those other than those for assembling the bottom member are incorporated therein. (c) Both the bottom and top parts 1 and 2 of these covers have hollowed out parts, and these parts are designed to provide soundproofing and are easily removable, at least in the areas that require adjustment and maintenance of this internal combustion engine. Assembled cover 4
3, 44, 45° 45', 45", 46. Each closure member 40, 4 has at least one penetration on either side of the front end and the output end.
6, it is closed acoustically. 2. The invention according to claim 1, which includes a rotation speed and/or torque converter directly flanged to the internal combustion engine body, in which the cover 1 and 2 are such converters 4 and 5. An internal combustion engine characterized by incorporating 3. The invention according to claim 2, which is equipped with a transmission that is directly flanged to the clutch, is characterized in that it satisfies all of the following characteristics (7), (a), and (of course) Internal combustion engine. (7) The cover closing part 6 on the output end side is the internal combustion engine main body 3.
A transmission cover main body material 35, which is separate from the cover, is suspended from the solid floor sound guide so that the transmission 5 is sandwiched in a U-shape from below. , and a cover 37 fixed to it to close its upper side. (a) At the connection part of the transmission 5 to the internal combustion engine main body 3, a gap is provided between the internal combustion engine main body cover and the transmission cover 35, and the gap is configured as an elastic rubber band. It is sealingly bridged by a preferred sleeve 39. (Mold) The transmission cover 35 has a sound-reducing material 32 and a protruding pipe 33 surrounding the output shaft 31 on the output end side.
, and is closed by a cover 40. 4. In the invention according to any one of claims 1 to 3, the bottom cutout hole of the canopy bottom member 1 is provided with an easily removable cover 43 adapted to cover the oil sump 41 in its shape. An internal combustion engine characterized in that it is closed. 5. An internal combustion engine according to any one of claims 1 to 4, characterized in that it satisfies both the following characteristics (7) and (a). (A) The hollow holes on both the left and right side surfaces in the longitudinal direction of the internal combustion engine main body 3 are covered with a cover 45 that is substantially horizontally divided into a plurality of parts 45' and 45'', two of which are a preferred example. (a) If necessary, the cover portions 45', 45 are attached to the upper member 2, where the divided portions are adjacent to each other.
"The abutting span member 49 is assembled in a removable manner. 6. In the invention according to any one of claims 1 to 5, the engine support is provided through an elastic material that blocks solid floor sound conduction. The internal combustion engine is characterized by satisfying all of the following characteristics (7). (7) Those members 56 that block solid floor sound Inside, it is assembled to both the engine body 3 and an engine body support stand 55 that is also pulled out from the canopy. (a) Such support stand 55 is fixedly held on the vehicle chassis 54. (1) A protruding pipe 5 provided on the canopy bottom member 1.
Rubber sleeves 57 are installed in order to prevent airborne noise from coming out between the engine body support stand 55 and the engine body support stand 55.