JP2000170543A - Vibration sound reducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the responsiveness of vibration damping by a simply structured vibration absorbing means so as to increase the reducing effect of a vibration sound in a vibration sound reducing device including the vibration absorbing means provided in a passage forming body for forming a liquid passage faced by at least one of a vibration generation section to absorb vibration transmitted from the vibration generation section through liquid in the liquid passage. SOLUTION: A vibration absorbing means 16 is provided with a bottomed cylindrical closing member 18 closing an attaching hole 17 and attached to an outer wall part 11b, a movable member 19 having a disk pressure receiving part 19a facing a liquid passage 1 and disposed in the closing member 18, an elastic supporting member 120 fixed to the closing member 18 and supporting the movable member 19 to be movable in a direction along the axis of the closing member 18, and a spring 21 for energizing the movable member 19 toward the liquid passage side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passage forming member which forms a liquid passage which faces at least a part of a vibration generating portion, and transmits a vibration transmitted from the vibration generating portion via the liquid in the liquid passage. The present invention relates to a vibration noise reduction device provided with vibration absorbing means for absorbing vibration.

[0002]

2. Description of the Related Art In a water-cooled internal combustion engine, a vibration absorbing means is provided on an outer wall portion of an engine body in order to reduce a piston slap noise caused by a collision of a piston with an inner surface of a cylinder portion. A sound reduction device is already known, for example, from Japanese Patent Application Laid-Open No. 10-184444.

[0003]

According to the vibration noise reduction device disclosed in the above publication, the pressure fluctuation of the cooling water is absorbed by the bending of the elastic film whose one surface faces the cooling water passage, and the cooling water is cooled. The exciting force acting on the outer wall of the engine main body from water is effectively reduced, and the piston slap noise radiated from the engine main body is reduced without increasing the weight of the engine main body.

However, in the above publication, vibration is absorbed by bending of the elastic film to reduce vibration noise.
It is hard to say that the vibration damping response is excellent, and there is a concern about the effect of reducing vibration noise.

The present invention has been made in view of the above circumstances, and provides a vibration sound reducing device in which the vibration damping effect is improved by increasing the vibration damping response by a simple structure of vibration absorbing means. With the goal.

[0006]

In order to achieve the above object, according to the present invention, the vibration generating unit is provided in a passage forming body which forms a liquid passage facing at least a part of the vibration generating unit. A vibration-absorbing means for absorbing vibration transmitted from the liquid through the liquid in the liquid passage, wherein the outer wall of the passage-forming body is provided with a mounting hole extending between the outer and inner surfaces of the outer wall. A closing member which is formed in a cylindrical shape with a bottom closed at an outer end and which is closed to the mounting hole to be attached to the outer wall portion, and a disk which has one surface facing the liquid passage inside the inner end of the closing member. A movable member having a pressure-receiving portion in the shape of being disposed in the closing member, and an outer peripheral portion fixed to an inner end opening of the closing member and moving the movable member in a direction along an axis of the closing member. Elastic support member for supporting A spring force formed between the movable member and the elastic support member and the closing member, and housed in a spring chamber separated from the liquid passage to urge the movable member toward the liquid passage. The vibration absorbing means is constituted by a spring exhibiting the following.

According to such a configuration, the vibration generated in the vibration generating section induces the vibration of the liquid in the liquid passage. However, the movable member having the pressure receiving section facing the liquid passage is connected to the spring in the spring chamber. By moving in the axial direction of the closing member while expanding and contracting, the pressure fluctuation of the liquid is absorbed, and the exciting force acting on the passage forming body from the liquid is effectively reduced, and the liquid is radiated from the passage forming body. Vibration noise is reduced. In addition, the pressure fluctuation of the liquid is absorbed by the expansion and contraction of the spring in the spring chamber, and the responsiveness of vibration damping is remarkably improved as compared with the one utilizing the bending of the elastic film.

[0008] The invention according to claim 2 provides the above-mentioned claim 1.
In addition to the configuration of the invention described in the above, a screw member that is restricted from moving inward in the axial direction by the outer end closing portion of the closing member and coaxially and movably penetrates the outer end closing portion is the movable member. It is characterized by being screwed into, according to such a configuration,
By changing the screwing amount of the screw member into the movable member, the set load of the spring can be freely adjusted so as to obtain the maximum vibration sound absorbing effect.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

1 to 6 show an embodiment of the present invention. FIG. 1 is a perspective view of a cylinder block of a four-cylinder water-cooled internal combustion engine, and FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 3, FIG. 3 is an enlarged view of a main part of FIG. 2, FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3, FIG. 5 is a view showing a vibration mode of an outer wall surface of a cylinder block along an arrangement direction of each cylinder part, It is a figure showing a vibration acceleration characteristic.

1 and 2, a cylinder block 11 of a water-cooled four-cylinder internal combustion engine constitutes an engine body E as a passage forming body together with a cylinder head and an oil pan (not shown). the 11, first to fourth cylinder unit _131-134 are provided in parallel a vibration generating unit, the piston 12 ... we are engaged respectively slidably in the cylinders portions _131-134 . These cylinder portions _131-134 are
In this embodiment, the inner wall portion 1 of the cylinder block 11 is provided.
The cylinder liners 15 are cast into 1a, but may be formed by grinding the inner surface of the inner wall 11a. The also engine body E, the cooling water passage 14 as a liquid passage for circulating the liquid is formed, the cooling water channel 14 is formed in the cylinder block 11 so as to surround the respective cylinder portions _131-134 in common Waterway part 1
4a.

By the way, the piston 12 ... are present slight gaps between the outer and inner surfaces of the cylinder portions _131-134 of the piston 12 ... vertical movement of the respective cylinder portions _131-134 within ₄ Sometimes pistons 12 are cylinder parts 1
3 _{1-13 4} collides with the inner surface cylinder unit _131-134
4 is vibrated, and the vibration is transmitted to the cooling water in the cooling water passage 14. Since the cooling water is incompressible,
Even a slight vibration causes a pressure change, and the cooling water passage 14
When a vibration force is applied to the outer wall portion 11b of the cylinder block 11 facing the pressure due to a change in the pressure of the cooling water, the outer wall portion 11b vibrates, and the piston slap sound is emitted to the outside.

Therefore, vibration absorbing means 16, 16 for absorbing the vibration of the cooling water in the cooling water passage 14 and minimizing the application of the vibrating force to the outer wall portion 11b of the cylinder block 11 to reduce the piston slap noise. But each cylinder part 13 ₁
To 13 second and third cylinder portions 13 ₂ located in the intermediate position along the arrangement direction of _4, 13 ₃ of the sleeve bore center corresponding position, respectively, which is attached to the outer wall portion 11b of the cylinder block 11, At the outer wall 11b of the cylinder block 11, mounting holes 17... Corresponding to the respective vibration absorbing means 16, 16 are provided between the inner and outer surfaces of the outer wall 11b.

The vibration absorbing means 16 includes a closing member 18 that closes the mounting hole 17 and is attached to the outer wall 11b, a movable member 19 disposed in the closing member 18,
An elastic support member 20 that supports the movable member 9 in a direction along the axis of the closing member 18 and a spring 21 that exerts a spring force that urges the movable member 19 toward the cooling water passage 14.
And a screw member 22 which coaxially and movably penetrates the closing member 18 and is screwed into the movable member 19.

Referring to FIG. 3 and FIG. 4, a cylindrical boss 2 is formed on the outer wall 11b of the cylinder block 11.
4 is integrally provided, and a mounting hole 17 having an inner end opened to the water passage portion 14a is provided on the outer wall portion 11b such that the outer end is opened to the outer end of the boss portion 24. A female screw 25 is engraved on the inner surface of the mounting hole 17.

The closing member 18 is a cylindrical mounting cylinder 2 having a male screw 26 screwed to the female screw 25 provided on the outer peripheral surface.
7, a flange portion 28 extending radially outward from the outer end of the mounting cylinder portion 27, and a mounting cylinder portion 27 that is used when the male screw 26 is screwed into the female screw 25 and the mounting cylinder portion 27 is screwed into the mounting hole 17. The operating cylinder 29 has a hexagonal outer surface and is connected to the outer end of the flange 28 so that a tool for rotating the cylinder can be engaged.
And an end wall portion 30 for closing the outer end of the operation tube portion 29, and is formed in a bottomed cylindrical shape having an outer end closed by, for example, an aluminum alloy.

The closing member 18 is screwed into the mounting hole 17 so that its inner end, that is, the inner end of the mounting cylinder 27, does not protrude from the inner surface of the outer wall 11b of the cylinder block 14 toward the cooling water passage 14. The annular gasket 31 is sandwiched between the flange 28 and the boss 24.

The movable member 19 has a disk-shaped pressure receiving portion 19a whose one surface faces the water passage portion 14a of the cooling water passage 14 within the inner end portion of the closing member 18, and one end is coaxial with the center of the other surface of the pressure receiving portion 19a. And a shaft portion 19b integrally and continuously formed, and is formed of a metal such as an aluminum alloy or a synthetic resin having rigidity, and is coaxially disposed in the closing member 18.

The elastic support member 20 is formed in a disk shape with, for example, cloth, synthetic fiber or glass fiber reinforced rubber, synthetic resin or metal in order to improve its durability. The outer periphery of 20 is fixed to the inner end opening of closing member 18. That is, the closing member 18
A fitting concave portion 32 is provided in the inner peripheral portion of the inner end of the mounting cylindrical portion 27, and the outer peripheral portion of the elastic support member 20 fitted in the fitting concave portion 32 is formed in a ring shape from, for example, an aluminum alloy. The ring member 33 is press-fitted into the fitting recess 32 and is sandwiched between the closing member 18.

The shaft portion 19b of the movable member 19 penetrates the center of the elastic support member 20, and sandwiches the inner peripheral portion of the elastic support member 20 with the other surface of the pressure receiving portion 19a of the movable member 19. The metal retainer 34 is used for the elastic support member 2.
0 and is caulked to the pressure receiving portion 19a. Thereby, the movable member 19 is supported by the elastic support member 20 whose outer peripheral portion is fixed to the inner end opening of the closing member 18 so as to be movable in the direction along the axis of the closing member 18.

A spring chamber 35 is formed between the movable member 19 and the elastic support member 20 and the closing member 18 so as to be isolated from the water passage 14a of the cooling water passage 14. The coil-shaped spring 21 is housed in the spring chamber 35, and the outer end closing portion of the closing member 18, that is, the end wall portion 30.
And a retainer 34 that operates integrally with the movable member 19. As a result, the movable member 19 is elastically urged toward the water channel portion 14a of the cooling water channel 14.

At the center of the end wall portion 30 as the outer end closing portion of the closing member 18, an insertion hole 37 having an inner end opened in the spring chamber 35 and a diameter larger than the insertion hole 37 are formed. An outer end of the insertion hole 37 is provided coaxially with the shaft portion 19b of the movable member 19 so that a step is formed between the outer end of the insertion hole 37 and an inner end thereof. An inner end portion of the screw member 22 that penetrates the movable member 19 is screwed into the other end of the shaft portion 19b of the movable member 19.

The screw member 22 has an enlarged diameter head 22 at its outer end.
a is integrally provided, and the enlarged diameter head 22 a is housed in the housing hole 38. In addition, an engagement groove 39 for engaging a rotary operation tool (not shown) such as a driver is provided on an outer end surface of the enlarged diameter head 22a.
It may be a straight line as in this embodiment or a cross shape.

A washer 40 that engages with the enlarged diameter head 22a and a washer 40 between the enlarged diameter head 22a of the screw member 22 and the step between the insertion hole 37 and the storage hole 38. And a ring-shaped seal member 41 disposed at the center. Therefore, the engagement of the large-diameter head 22a with the washer 40 in which the seal member 41 is interposed between the end wall 30 of the closing member 18 and the axially inward movement of the screw member 22 is restricted. Will be.

Incidentally, the movement of the enlarged head 22a in accordance with the axial movement of the movable member 19 is about several μm, and the seal member 41 is inserted through the washer 40 regardless of the movement of the enlarged head 22a. It is in resilient contact with the step between the hole 37 and the storage hole 38, and the seal member 41 seals between the spring chamber 35 and the outside.

The engine body E of such a vibration absorbing means 16
In the state where the movable member 1 is attached to the movable member 1,
The pressure receiving portion 19 a and the elastic support member 20 are set so as not to protrude into the cooling water passage 14 from the inner surface of the outer wall portion 11 b of the cylinder block 11.

The mounting positions of the mounting hole 17 and the vibration absorbing means 16 are determined by the piston 12
It is desirable to be close to the position where the inner surfaces of the cylinder portions 13 ₂ and 13 ₃ are hit, and it is known that the timing of the slap vibration with respect to the crank angle is within 25 degrees before and after the top dead center of the piston 12. Before and after dead center 25
Assuming that the sum of the piston displacement in degrees and the axial length of the piston 12 is A, the mounting hole 17 and the vibration absorbing means 16 are desirably provided in a range A from the upper surface of the cylinder block 11.

[0028] According to the experiments conducted by the present inventors, velocity amplitude of the accompanying vibration to blow from the piston 12 of each cylinder unit _131-134 is along the arrangement direction of the cylinder portion _131-134 Te is intended to vary as shown in Figure 5, at the portion corresponding to the bore center of the cylinders portions _131-134 second and third cylinder portion 13 ₂ which is an intermediate portion along the arrangement direction of _4, 13 ₃ The speed amplitude increases. Thus, the mounting hole 17 and the vibration absorbing means 16, in a state in which from the side perpendicular to the arrangement direction of the cylinder portion _131-134 viewed cylinder block 11, the second and third cylinder portions 13 _2, 13 ₃ It is preferable that the portions corresponding to the bore center are disposed on the outer wall portion 11b of the cylinder block 11, respectively.

Next, the operation of this embodiment will be described. The outer surfaces of the pistons 12 and the cylinders 13 ₁
By minute gap exists between -13 ₄ of the inner surface, when the inner surface of the cylinder portion _131-134 piston 12 ... vibrates the respective cylinder portions _131-134 collide, the vibration is cooling It is transmitted to the incompressible cooling water in the water channel 14 and induces a pressure change of the cooling water. However, a mounting hole 17 is provided in the outer wall portion 11b of the cylinder block 11 at a portion facing the water channel portion 14a of the cooling water channel 14, and a vibration absorbing means 16 is mounted so as to close the mounting hole 17.

The vibration absorbing means 16 closes a mounting hole 17 and is a closing member 18 mounted on the outer wall 11b.
And a disc-shaped pressure receiving portion 19 having one surface facing the cooling water passage 14.
a movable member 19 having a
An elastic support member 20 having an outer peripheral portion fixed to the inner end opening of the closing member 18 and supporting the movable member 19 so as to be movable in a direction along the axis of the closing member 18; There is provided a spring 21 formed between the member 20 and the closing member 18 and housed in a spring chamber 35 separated from the cooling water passage 14 to urge the movable member 18 toward the cooling water passage 14. Therefore, the pressure fluctuation of the cooling water is absorbed by the movable member 19 having the pressure receiving portion 19 a facing the cooling water passage 14 moving in the axial direction of the closing member 18 while expanding and contracting the spring in the spring chamber 35. , Cooling water from the outer wall 1 of the cylinder block 11
The excitation force acting on 1b is effectively reduced.

Further, the vibration absorbing means 16 absorbs fluctuations in the pressure of the cooling water by expansion and contraction of the spring 21 in the spring chamber 35, and utilizes the bending of the elastic film (Japanese Patent Laid-Open No.
184444), the response of vibration damping can be improved.

Since the spring chamber 35 is isolated from the outside by the seal member 41, the sound due to the axial movement of the movable member 19 is not radiated from the closing member 18 to the outside, but is radiated from the cylinder block 11. Piston slap noise can be effectively reduced.

The axially inward movement of the closing member 18 is restricted by the end wall portion 30, and the screw member 22 that penetrates the end wall portion 30 coaxially and movably is provided on the shaft portion 1 of the movable member 19.
9b and the movable member 19 of the screw member 22
The set load of the spring 21 can be freely adjusted so as to obtain the maximum vibration sound absorbing effect by changing the screwing amount into the screw.

Further, the inner end of the closing member 18 and the movable member 1
Since the pressure receiving portion 19a and the elastic support member 20 do not protrude into the cooling water passage 14 from the inner surface of the outer wall portion 11b of the cylinder block 11, the flow of the cooling water in the cooling water passage 14 is prevented as much as possible. The flow of the cooling water in the cooling water passage 14 can be made smooth, and the cooling performance can be maintained at the same level as that of a conventional water-cooled internal combustion engine not equipped with the vibration absorbing means 16. .

[0035] Here, when showing the results of verification of the vibration acceleration of the outer wall 11b of the cylinder block 11 at a portion corresponding to the third cylinder portion 13 _3, which is shown in Figure 6, the vibration absorbing means Whereas the conventional one without 16 is relatively high as shown by the dashed line,
It is clear that the acceleration according to the present invention is effectively reduced as shown by the solid line, and the piston slap noise can be effectively reduced by the vibration absorbing means 16 according to the present invention.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in the above embodiment, the closing member 18 is attached to the outer wall 11b by screwing, but the closing member 18 may be pressed into the outer wall 11b.

In the above embodiment, the case where the present invention is applied to a water-cooled internal combustion engine has been described. However, the present invention is directed to a case where radiation is generated from a passage forming member which forms a liquid passage facing at least a part of a vibration generating portion. This can be widely implemented as a device for reducing the vibration noise generated.

[0039]

As described above, according to the first aspect of the present invention, the movable member having the pressure receiving portion facing the liquid passage moves in the axial direction of the closing member while expanding and contracting the spring in the spring chamber. By absorbing the pressure fluctuation, the vibrating force acting on the passage forming body from the liquid can be effectively reduced, and the vibration sound radiated from the passage forming body can be reduced. Moreover, since the pressure fluctuation of the liquid is absorbed by the expansion and contraction of the spring in the spring chamber, the response of the vibration damping is increased,
The effect of reducing vibration noise is further improved.

According to the second aspect of the present invention, by changing the screwing amount of the screw member into the movable member,
The set load of the spring can be freely adjusted so as to obtain the maximum vibration sound absorbing effect.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cylinder block of a four-cylinder water-cooled internal combustion engine.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3;

FIG. 5 is a view showing a vibration mode of an outer wall surface of a cylinder block along an arrangement direction of each cylinder portion.

FIG. 6 is a diagram illustrating vibration acceleration characteristics with respect to frequency.

[Explanation of symbols]

13 _{1 to} 13 ₄ ··· Cylinder part as vibration generating part 14 ··· Cooling water path as liquid passage 11b · · · Outer wall part 16 ··· Vibration absorbing means 17 ··· Mounting hole 18 ··· closing member 19 movable member 19a pressure receiving part 20 elastic support member 21 spring 22 screw member 30 end wall as outer end closing part 35 spring chamber E ... Engine body as passage forming body

Claims (2)

[Claims] [Claim 1] A vibration generating unit _(131-134) of at least a portion of the face was liquid passage (14) forming a passage defining member (E), the vibration generating unit _(131-134) The vibration-absorbing means (16) for absorbing vibration transmitted from the liquid through the liquid in the liquid passage (14), the outer wall portion (11b) of the passage forming body (E).
The mounting hole (1) extending between the outer surface of the outer wall portion (11b)
7) is provided, is formed in a bottomed cylindrical shape with an outer end closed, and closes the mounting hole (17) to close the outer wall (1).
1b) has a closing member (18) attached to the closing member (18), and a disc-shaped pressure receiving portion (19a) having one surface facing the liquid passage (14) inside the inner end of the closing member (18). A movable member (19) disposed in the inside of the closing member (18) is fixed to an inner end opening of the closing member (18), and the movable member (19) is oriented along an axis of the closing member (18). Elastic support member (2)
0) and a spring chamber (3) formed between the movable member (19) and the elastic support member (20) and the closing member (18) and isolated from the liquid passage (14).
A spring (2) which is housed in the fifth member (5) and exerts a spring force for urging the movable member (19) toward the liquid passage (14);
(1) The vibration sound reducing device, wherein the vibration absorbing means (16) is constituted. 2. An outer end closing portion (3) of said closing member (18).
0), the screw member (2) is restricted from moving inward in the axial direction and coaxially and movably penetrates the outer end closing portion (30).
2. The vibration noise reduction device according to claim 1, wherein 2) is screwed into the movable member.