JPH0514534U - Engine sound insulation cover - Google Patents

Abstract

(57) [Summary] [Purpose] To efficiently reduce the noise of the engine by disposing the sound insulation cover of the engine close to the engine body. [Structure] Chain cover 16, which covers the front of the camshaft drive chamber,
The front of 17 is covered with the first engine covers 71 and 72, and the upper part of the rocker covers 6 and 7 is covered with the second engine cover 91. Further, the upper end side 73 having the bent portion 75 is extended to a position close to the flange portions 35 and 36.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine sound insulation cover that reduces noise from an engine mounted on an automobile or the like.

[0002]

[Prior Art]

 BACKGROUND ART Conventionally, in an engine of an automobile or the like, a cylinder block vibrates in an up-down direction and a left-right direction due to an exciting force generated by an explosion in a cylinder and a rotation of a crankshaft. Then, this vibration reaches the rocker cover and the like via the cylinder head, and vibrates the rocker cover to generate noise.

Therefore, various techniques have been conventionally used to reduce the noise generated by the engine. For example, as disclosed in Japanese Patent Laid-Open No. 55-140709, a sound insulating cover covering the front of the engine is used. There is one that tried to reduce the radiated sound to the outside of the car. In addition, a hood insulator is attached to the inner surface of the engine hood to reduce the noise emitted outside the vehicle.

[0004]

[Problems to be solved by the device]

 However, in these conventional sound insulation devices, since the sound insulation cover or the hood insulator is provided on the vehicle side on which the engine is mounted, only a part of the sound emission can be reduced, and the sound insulation efficiency is reduced. Cannot be improved. In particular, there is a problem that the sound emitted from the front of the cylinder head front wall located in front of the camshaft drive chamber, which has a large contribution to the emitted sound of the engine, and the sound emitted from above the rocker cover cannot be effectively shielded.

In view of the above conventional problems, it is an object of the present invention to efficiently reduce the noise of the engine by disposing the sound insulation cover of the engine near the engine body. ..

[0006]

[Means for Solving the Problems]

 For this reason, the present invention is a sound insulation cover for an engine, which is arranged in the vicinity of the engine, in which a rocker cover and a cylinder head are joined by a flange portion that protrudes outward, and is located in front of the camshaft drive chamber. The first engine cover that covers the front of the front wall portion of the cylinder head and the second engine cover that covers the upper part of the rocker cover are provided close to the engine so that they do not project outward from the flanges. The upper end side of the first engine cover and the lower end side of the second engine cover are extended to a position close to the flange portion, and an inwardly bent portion is provided at the position.

[0007]

[Action]

 In such a configuration, the sound insulation cover of the engine is arranged close to the engine body, which means that the sound insulation cover is arranged near the engine, which is the noise source, so that the sound emitted from the engine can be efficiently emitted. The size can be reduced and the size can be reduced.

Further, by the first engine cover that covers the front of the front wall of the cylinder head located in front of the camshaft drive chamber, the front of the cylinder head located in front of the camshaft drive chamber where the radiated sound contribution of the engine is large. The sound emitted from the wall is shielded, and the sound emitted from the upper part of the rocker cover, which has a large contribution to the upward sound emitted from the engine, is shielded by the second engine cover that covers the upper part of the rocker cover. Therefore, the radiated sound can be efficiently reduced.

Further, by providing the first engine cover and the second engine cover so close to the engine that they do not protrude outward from the flange portion, respectively, even if the engine cover is attached to the engine, the covers will be Since it does not protrude from the entire width of the engine, the total width of the engine does not become large, and thus unnecessary installation space is not required.

Further, since the upper end side of the first engine cover and the lower end side of the second engine cover are extended to a position close to the flange portion, air as a sound insulation layer is provided between the cover and the engine. The layers can be effectively provided, and by providing an inwardly bent portion at a position close to the flange portion, it is possible to prevent noise from leaking through the air layer, and at the same time, the end portion of the engine cover can be prevented. Is protected.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view in which an engine cover according to the present invention is attached to a V-type engine 1. Fuel is supplied to the V-type engine 1 from a fuel pump (not shown) via a fuel gallery 2. Here, in the fuel gallery 2, a fuel injection valve 13 and a fuel injection valve 14 are attached in a bank 8 between the rocker covers 6 and 7 mounted above the cylinder heads 4 and 5. Here, the respective rocker covers 6 and 7 have the flange portions 31 and 32 provided at the lower end portions thereof joined to the flange portions 35 and 36 provided at the upper end portions of the cylinder heads 4 and 5 via the packing 33. ing. The V-type engine 1 according to this embodiment has an intake collector 10 disposed above the cylinder head 5 located on the vehicle rear side when mounted on a vehicle and protruding rearward from the rocker cover 7 of the cylinder head 5. Intake air is supplied through the intake manifold 9.

A crankshaft 11 is rotatably supported by the cylinder block 14, and an accessory drive pulley 12 fixed to the crankshaft 11 drives an accessory such as a compressor 13 and rotates the crankshaft 11. The force is applied to the inside of the cylinder block 14 (in this embodiment, the front side of the paper surface) and the camshaft drive chambers provided inside the cylinder heads 4 and 5 through a timing chain or the like (not shown) that travels through the cylinder. It is transmitted to a cam shaft (not shown) provided on the heads 4 and 5.

The V-type engine 1 is provided with chain covers 16 and 17 as front wall portions of a cylinder head that covers the front of the camshaft drive chamber provided in the cylinder heads 4 and 5. The fronts of the chain covers 16 and 17 are covered with first engine covers 71 and 72. Here, the first engine covers 71 and 72 are provided so as not to interfere with the accessory drive belt 15 or the like for driving the accessory such as the compressor 13, and the first engine covers 71 and 72 are further provided. The chain covers 16 and 17 are fastened to the chain covers 16 and 17 so as to cover the front portions of the chain covers 16 and 17 to the extent that they do not project outward from the flange portions 35 and 36. Further, a second engine cover 91 that covers above the rocker cover 6 of the cylinder head 4 located on the front side of the vehicle and the rocker cover 7 of the cylinder head 5 located on the rear side of the vehicle projects outward from the flange portions 31 and 32. It is fastened close to the rocker covers 6 and 7 at a height that does not fit.

In both the first engine cover 71, 72 and the second engine cover 91, a sound absorbing part 62 made of a sound absorbing material such as felt is attached to an outer plate part 61 made of a heat-resistant synthetic resin such as 6-6 nylon. It is configured by bonding with. Further, the upper end sides 73, 73 of the substantially flat plate-shaped first engine covers 71, 72 are extended to a position close to the flange portions 35, 36, and the upper end sides 73, 73 are bent inwardly 75, 75 are provided. Here, the protruding length of the bent portion 75 is formed longer than the thickness t _{62 of} the sound absorbing portion 62, and therefore, compared with the distance C ₇₆ between the inner surface 64 of the sound absorbing portion 62 and the cylinder heads 4 and 5. The distance C ₇₇ between the tip portion 77 of the bent portion 75 and the cylinder heads 4 and 5 is small.

On the other hand, in the second engine cover 91, the ceiling wall 91a that covers above and the front of the rocker covers 6 and 7 and the first engine covers 71 and 72 that are continuous with the ceiling wall 91a are provided. A side wall 91b formed on the side of the engine front side to be mounted, a side wall 91d (not shown) formed on the side of the engine rear side, and a bank on the front side of the vehicle when the V-type engine 1 is mounted on the vehicle. The ceiling wall 91a includes a side wall 91c that covers the side surface of the rocker cover 6 and a side wall 91e that covers the side surface of the rocker cover 7 of the bank on the vehicle rear side when the V-type engine 1 is mounted on the vehicle. The side walls 91b, 91c, 91d and 91e are connected to each other and integrally formed in a concave shape. Further, also in the second engine cover 91, similarly to the above, the lower end sides 93 of the side walls 91b, 91c, 91d and 91e are extended to the positions close to the flange portions 31 and 32, and the lower end portions are further extended. An inwardly bent portion 95 is provided on the side 93. Here, the protruding length of the bent portion 95 is also formed longer than the thickness t ₆₂ of the sound absorbing unit 62, it has been the bend compared to the distance C ₉₆ between the inner surface 64 and b Kkakaba 6 and 7 of the sound absorbing portion 62 The distance C ₉₇ between the tip portion 97 of the portion 95 and the rocker covers 6 and 7 becomes small.

Further, as shown in FIG. 3, an oil supply port 21 for supplying engine oil into the V-type engine 1 is provided as a working opening above the rocker cover 6 of the bank on the front side of the vehicle. A female screw 22 is cut in the oil supply port 21 so that a screw portion 19a of an oil filler cap 19 as a closing member is screwed. The top plate portion 91a of the second engine cover 91 is provided with an opening 52 having a diameter larger than the diameter of the fuel filler port 21 at a position facing the fuel filler port 21. A bent portion 51 which is bent downward is provided, that is, in the direction toward the rocker cover 6. Here, the protruding length of the bent portion 51 also depends on the thickness t of the sound absorbing portion 62.₆₂It is formed longer, so the distance C between the inner surface 64 of the sound absorbing part 62 and the rocker cover 6 ₉₆ In comparison with the distance C between the tip 53 of the bent portion 51 and the rocker cover 6₅₃Will be small.

A seal ring 20 is fitted on the outer peripheral side of the screw portion 19 a of the oil filler cap 19. Here, in the present embodiment, when the sound absorbing portion 62 is adhered to the outer plate portion 61 with an adhesive, the flat back surface 65 of the side walls 91b of the first engine covers 71, 72 and the second engine cover 91, Not only the flat surface 66 of the sound absorbing portion 62 is coated with an adhesive to bond the same, but in the first engine covers 71 and 72, to the bent portions 75 and 75, and to the second engine cover 91. Then, an adhesive is applied to the bent portion 95, and to the bent portion 51 in the opening 52 in the top plate portion 91a of the second engine cover 91, and the end surface 67 of the sound absorbing portion 62 is also set to the first portion. The engine covers 71, 72, the side wall 91b of the second engine cover 91, or the top plate portion 91a are securely bonded.

Next, the operation according to this embodiment will be described. In this structure, the first engine covers 71 and 72 are fixed to the chain covers 16 and 17 by covering the front portions of the chain covers 16 and 17, and the second engine cover 91 is fixed to the rocker covers 6 and 7. The engine covers 71, 72 and 91 are held close to the V-type engine 1 main body, and the engine covers 71, 72 and 91 as sound insulation covers are brought close to the V-type engine 1 main body which is a noise source. As a result, the sound emitted from the V-type engine 1 can be efficiently reduced.

Further, the engine covers 71, 72 and 91 are fastened close to the chain covers 16 and 17 and the rocker covers 6 and 7 at a height such that the engine covers 71, 72 and 91 do not project outward from the flanges 35 and 36 and the flanges 31 and 32. Therefore, the V-type engine 1 can be made compact without increasing the size of the engine cover. The contribution rate of each radiated sound generation point of the V-type engine 1 is as shown in Table 1 when the V-type 6-cylinder engine is rotated at 4000 rpm, for example. Radiation from above the rocker cover and from the front of the chain cover is shown. Loud.

[0020]

[Table 1]

In the present embodiment, the first engine covers 71, 72 are fixed directly in front of the chain covers 16, 17 to efficiently shield the radiated sound from the front of the chain covers 16, 17. Further, in the second engine cover 91, the ceiling wall 91a, the side walls 91b, 91c, 91d, and 91e are coupled to each other and integrally formed in a concave shape, and the rocker cover 6 and the rocker cover 7 are provided above and to the side. The sound emitted from the rocker cover 6 and the rocker cover 7 is effectively shielded since it is surrounded. That is, for example, when a V6 engine is rotated at 40000 rpm, as shown in FIGS. 4 and 5, the noise level above the rocker cover and the noise level in front of the chain cover are the same as those of the conventional example (shown by the solid line). In comparison, it is much smaller, as shown by the dotted line.

Further, in the present embodiment, in the first engine covers 71 and 72, the protruding length of the bent portion 75 is formed longer than the thickness t _{62 of} the sound absorbing portion 62, and the inner surface 64 of the sound absorbing portion 62 is formed. An air layer 76 effective for sound insulation is provided between the cylinder head 4 and the cylinder heads 4 and 5, and the sound insulation effect is also provided by the air layer 76, and the tip portion 77 of the bent portion 75 and the cylinder heads 4 and 5 are the distance C ₇₇ as small things than the thickness C ₇₆ of the air layer 76, also prevents escape of the sound from the tip portion 77.

Similarly, in the second engine cover 91, the protruding length of the bent portion 95 is formed longer than the thickness t _{62 of} the sound absorbing portion 62, and the inner surface 64 of the sound absorbing portion 62 and the rocker covers 6 and 7 are connected to each other. An air layer 96 effective for sound insulation is provided between the air layer 96 and the sound insulation effect by the air layer 96, and the distance C ₉₇ between the tip 97 of the bent portion 95 and the rocker covers 6 and 7 is set to the air layer 96. The thickness is smaller than the thickness C ₉₆ to prevent the sound from escaping from the tip portion 97.

Similarly, in the second engine cover 91, with respect to the opening 52 provided at a position facing the fuel filler port 21, the protruding length of the bent portion 51 is equal to the thickness of the sound absorbing portion 62. An air layer 96 that is formed longer than t ₆₂ and is effective for sound insulation is provided, and the distance C ₅₃ between the tip 53 of the bent portion 51 and the rocker cover 6 is smaller than the thickness C _{96 of the} air layer 96. As a result, the escape of sound from the tip portion 53 is also prevented.

Further, as the operation and effect according to the present embodiment, in the bent portion 75, the bent portion 95 and the bent portion 51, the end surface 67 of the sound absorbing portion 62 also has the first engine covers 71, 72 and the second engine cover 72, respectively. Since it is securely adhered to the side wall 91b of the engine cover 91 or the top plate portion 91a, the sound absorbing portion caused by the intrusion of rainwater at the bent portions 75 and 95 and the oil entering at the bent portion 51 during oil supply. It is possible to prevent the peeling of 62 from the outer plate portion 61, and it is possible to prevent the sound absorbing portion 62 from bubbling up in the bending portion 75, the bending portion 95, and the bending portion 51, so that the first engine cover 71, The life of the 72 and the second engine cover 91 can be extended.

Further, as a configuration of the top plate portion 91a of the second engine cover 91 related to the fuel filler port 21 provided above the rocker cover 6, there is also a configuration as shown in FIG. However, the description of the components described with reference to FIG. 3 is omitted. That is, the top plate portion 91 a of the second engine cover 91 is provided with the opening 42 including the stepped portion 41 at a position facing the fuel filler port 21.

A gripping portion 44 a for gripping the opening end portion 42 a and a collar portion of the oil filler cap 19 when the oil filler cap 19 is attached to the oil filler port 21 are provided in the opening portion 42. A rubber gripping member 44, which is composed of a lip portion 44b that is pressed and sandwiched between the rocker cover 6 by 19b and a connecting portion 44e that connects the gripping portion 44a and the lip portion 44b, is provided around the entire circumference. Mated across. Here, the protruding length of the stepped portion 41 or else, is formed longer than the thickness t ₆₂ of the sound absorbing unit 62, since the further the gripping portion 44a is gripped by the opening end 42a, with among the sound absorbing portion 62 The distance C ₄₄ between the lower end 44f of the gripping portion 44a and the rocker cover 6 is smaller than the distance C ₉₆ between the surface 64 and the rocker cover 6.

In the oil filler cap 19, a seal ring 20 having a rigidity higher than the rubber rigidity of the lip portion 44b is fitted on the inner peripheral side of the lip portion 44b and on the outer peripheral side of the screw portion 19a. Further, as the screw portion 19a of the oil filler cap 19 is screwed into the female screw 22, the distance between the collar portion 19b of the oil filler cap 19 and the rocker cover 6 becomes smaller, so that the collar portion 19b becomes smaller. The lip portion 44b of the grip member 44 is pressed and pinched by the rocker cover 6. Therefore, the space 91 between the rocker cover 6 and the second engine cover 91 and the outer space 99 of the second engine cover 91 are isolated by the gripping member 44, so that the noise generated from the rocker cover 6 is replenished by the refueling. It is possible to prevent leakage to the outside through the opening 42 related to the mouth 21.

When the oil filler cap 19 presses and holds the gripping member 44 on the rocker cover 6, the gripping member 44 grips the opening end 42a by the gripping portion 44a, so that the gripping member 44 is Since the second engine cover 91 is indirectly gripped, the second engine cover 91 is reliably supported, the support rigidity of the second engine cover 91 is increased, and even if the rocker cover 6 vibrates, (2) It is possible to prevent the engine cover 91 from vibrating and prevent the generation of new noise.

Further, in this embodiment, the lip portion 44b of the gripping member 44 is pressed and sandwiched by the rocker cover 6 by the collar portion 19b, and the rubber rigidity of the lip portion 44b is greater than that of the seal ring 20. Since it is set small, the fastening force applied to the screw portion 19a of the oil filler cap 19 is mainly used for elastically deforming the seal ring 20, so that the sealing action of the seal ring 20 is secured as usual. Since the second engine cover 91 is securely held via the lip portion 44b, the second engine cover 91 is held by the soft lip portion 44b having a small rigidity, that is, it is difficult for sound and vibration to be transmitted. Furthermore, the oil filler cap 19 There is no reduction in the tightening force of and there is no risk of oil leakage.

Further, in a state where the oil filler cap 19 is removed from the rocker cover 6 in order to inject oil from the oil supply port 21, the lip portion 44 b of the grip member 44 is provided on the upper surface of the rocker cover 6 and the second engine cover 91. It comes into contact with itself due to its own weight, so that the sealing property around the oil supply port 21 is secured when the oil is injected. Even if oil leaks from the oil supply port 21 during refueling work, the leaked oil is stopped by the lip portion 44b, and it is possible to reliably prevent the oil from leaking to the upper surface of the rocker cover 6.

[0032]

[Effect of the device]

 As described above, according to the present invention, the first engine cover that covers the front of the cylinder head front wall portion located in front of the camshaft drive chamber and the second engine cover that covers the upper portion of the rocker cover are provided. Each of them is provided close to the engine so as not to project outward from the flange portion, and the upper end side of the first engine cover and the lower end side of the second engine cover are extended to a position close to the flange portion. Since the inward bent portion is provided at the position, the sound emitted from the engine can be efficiently reduced, the size can be reduced, and the front of the camshaft drive chamber, which is the largest source of the engine noise, can be achieved. The sound radiated from the front of the front wall of the cylinder head located at and from above the rocker cover was reliably shielded, so the effect of effective reduction of the radiated sound can be achieved. That.

[Brief description of drawings]

FIG. 1 is a schematic side view of a V-type engine with a cover mounted thereon according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along the line AA in FIG.

FIG. 3 is a partial cross-sectional view showing an embodiment of the fuel filler of the V-type engine with the cover according to the embodiment being mounted thereon.

FIG. 4 is a noise level characteristic diagram showing a noise reduction effect at 1 m above the V-type engine according to the embodiment.

FIG. 5 is a noise level characteristic diagram showing a noise reduction effect 1 m in front of the V-type engine according to the embodiment.

FIG. 6 is a partial cross-sectional view showing another embodiment of the fuel filler port of the V-type engine with the cover according to the embodiment being mounted thereon.

[Explanation of symbols]

 1 V-type engine 4 Cylinder head 5 Cylinder head 6 Rocker cover 7 Rocker cover 10 Intake collector 16 Chain cover 17 Chain cover 31 Flange portion 32 Flange portion 35 Flange portion 36 Flange portion 61 Outer plate portion 62 Sound absorbing portion 71 1st engine cover 72 First engine cover 73 Upper end side 75 Bent portion 91 Second engine cover 93 Lower end side 95 Bent portion

Claims (1)

[Scope of utility model registration request] 1. A sound insulation cover for an engine, wherein the rocker cover and the cylinder head are joined to each other by a flange portion projecting outward, and the sound insulation cover is provided in the vicinity of the engine. The cylinder head is located in front of the camshaft drive chamber. A first engine cover that covers the front of the front wall portion and a second engine cover that covers the upper portion of the rocker cover are provided close to the engine to the extent that they do not project outward from the flange portion, and the first engine cover is provided. And a lower end side of the second engine cover are extended to a position close to the flange portion, and an inwardly bent portion is provided at the position.