JPH10292850A - Engine mount device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the vibration property (the spring constant) of a mount rubber respond to the vibration property of an engine unit without changing the body form of a vehicle, and to improve the durability, in an engine mount device to prevent the transmission of the engine vibration to a body by providing it between the engine and the body. SOLUTION: This engine mount device is composed by furnishing an engine side metal fitting 21 fastened with an engine; a body side metal fitting 22 fastened with a body; and a mount rubber 23 provided between an engine side bearing surface 24 provided to the engine side metal fitting 21, and a body side bearing surface 32 provided to the body side metal fitting 22. While it is composed to make the width size of the mount rubber 23 between the engine side bearing surface 24 and the body side bearing surface 32 even, an angle regulating step 33 is formed to the body side bearing surface 32, and it is so composed that the angle (θ1) of the engine side bearing surface 24 to the horizontal direction is at least less than 45 deg. (θ1<45 deg.).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine mounting device, and more particularly to an engine mounting device that is interposed between an engine and a body to prevent engine vibration from being transmitted to the body.

[0002]

2. Description of the Related Art In general, an automobile engine is supported on a vehicle frame via an engine mount device having an insulator (mount rubber) having vibration damping performance according to its vibration characteristics. The vibration generated by the engine is reduced by using the vibration absorption performance of the engine. In designing this engine mount device, it is necessary to select horizontal and vertical spring constants suitable for the vibration characteristics of the mounted engine.

As shown in FIG. 5, for example, a conventional engine mounting apparatus vulcanizes and bonds a mount rubber 6 between an engine-side metal fitting 2 and a body-side metal fitting 3 when a seating surface 4 of the engine-side metal fitting 2 is bonded. Is made parallel to the seating surface 5 of the body side fitting 3. In the engine mount device 1 having such a structure, the seat surface 4 of the engine side bracket 2 and the seat surface 5 of the body side bracket 3 are generally inclined by 45 ° with respect to the horizontal direction (the direction indicated by arrow X in the figure). When installed with
Horizontal spring constant (K1x) and vertical spring constant (K1x)
1y) indicates the same value.

FIG. 4 shows the relationship between the inclination angle (θ) of the seat surface 4 of the engine side bracket 2 with respect to the horizontal direction X and the spring constant of the mount rubber 6. The characteristic indicated by the solid line in FIG. 3 is the spring constant characteristic when the seat 4 of the engine-side fitting 2 is parallel to the seat 5 of the body-side fitting 3. In the drawing, K1x indicates a horizontal spring constant, and K1y in the drawing indicates a horizontal spring constant.

[0007] As shown in FIG.
When the seat surface 4 and the seat surface 5 of the body-side bracket 3 are inclined by 45 ° with respect to the horizontal direction (the direction indicated by the arrow X in the figure), the spring constant ratio (K1x / K1y) in the horizontal and vertical directions
Becomes 1. On the other hand, in a region where the inclination angle of the engine side fitting 2 is 45 ° or more, the horizontal spring constant K1x
Becomes larger than the spring constant K1y in the vertical direction, and in the region where the inclination angle is 45 ° or less, the spring constant K1y in the vertical direction becomes larger than the spring constant K1x in the horizontal direction. Therefore, when the engine unit 7 having the same vibration characteristics is mounted on the same vehicle body, the practically satisfactory anti-vibration performance can be obtained even with the engine mount device 1 having the above configuration.

However, in response to the recent demand for diversification of vehicles, a vehicle body assembly system in which a plurality of types of engine units 7 having different vibration characteristics are mounted on the same vehicle body has been widely used. In this case, it has become extremely difficult to provide substantially satisfactory vibration damping characteristics to all types of vehicles by using the engine mount device 1 having the same vibration absorbing characteristics as described above.

That is, when engine units having different vibration characteristics are mounted in an engine room having the same dimensions and shape, it is necessary to adjust the vibration characteristics (spring constant) of the mount rubber 6 according to the vibration characteristics of the engine. However, as described above, it is substantially impossible to change the mounting position of the engine unit as long as the size and shape of the engine room are the same. For this reason, in order to adjust the spring constant of the mount rubber 6, it is necessary to change the shape of the vehicle frame so as to correspond to the vibration characteristics of the engine and to adapt the angles of the seat surfaces 4 and 5, which is very uneconomical. Was.

Accordingly, an engine disclosed in Japanese Utility Model Laid-Open Publication No. 58-184048 is disclosed as one that can adjust the vibration characteristic (spring constant) of the mount rubber to correspond to the vibration characteristic of the engine without changing the frame shape of the vehicle. Mounting devices have been proposed. FIG.
48 shows the engine mounting device 10 disclosed in FIG. 6, the same reference numerals are given to the components corresponding to the components of the engine mount device 1 shown in FIG. 5, and the description thereof will be omitted.

An engine mount device 10 shown in FIG.
Are different in thickness of the mounting rubber 9 so that the engine-side end surface 9a and the body-side end surface 9b of the mounting rubber 9 are different.
Have a non-parallel configuration, whereby an inclination angle θ according to the vibration characteristics of an engine unit (not shown) is given between the seating surface 4 of the engine side fitting 2 and the seating surface 5 of the body side metal 3. It is characterized by the following.

The inclination angle θ is such that the horizontal spring constant K1x and the vertical spring constant K1y of the engine mount device 10 maintain a predetermined ratio required for vibration damping according to the vibration characteristics of the mounted engine unit. Selected. The engine mounting device 10 having the tilt angle θ selected as described above includes the engine fixing bracket 11 and the body 1
2 are fixed using bolts 8, whereby the engine unit is provided with appropriate vibration damping performance.

[0011]

In the engine mounting apparatus 10 having the above-described structure, the thickness of the mounting rubber 9 is varied so that the engine-side end surface 9 of the mounting rubber 9 is formed.
a and the body side end surface 9b are non-parallel,
The mounting rubber 9 can be used without changing the shape of the body 12.
Can be made to correspond to the vibration characteristics of the engine unit.

However, the thickness of the mounting rubber 9 provided on the engine mounting device 10 is not uniform.
The minimum portion has a thickness indicated by an arrow H1 in FIG. 6, and the maximum portion has a thickness indicated by an arrow H2 (H1 <H2). For this reason,
The stress (strain) generated when a load is applied to the mount rubber 9 is different between the portion having the thickness H1 and the portion having the thickness H2. Particularly, a large stress is applied to the portion having the small thickness H1. This causes a problem that durability is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a vibration characteristic (spring constant) of the mount rubber corresponding to the vibration characteristic of the engine unit without changing the body shape of the vehicle, and has durability. It is an object of the present invention to provide an engine mount device capable of improving the performance.

[0014]

In order to solve the above-mentioned problems, according to the present invention, an engine-side fitting fastened to an engine, a body-side fitting fastened to a vehicle body, and the engine-side fitting are provided. An engine mount device comprising: an engine-side seating surface provided and an insulator interposed between a body-side seating surface provided on the body-side metal fitting, wherein the engine-side seating surface, the body-side seating surface, By forming the insulator so that the width dimension of the insulator between them becomes uniform, and by forming an angle adjusting step on the body side seating surface, the angle (θ) formed by the engine side seating surface with respect to the horizontal direction can be reduced. At least less than 45 ° (θ <45
°).

In the engine mount device having the above-described structure, the width of the insulator between the engine-side seating surface and the body-side seating surface is made uniform, so that the insulator is biased when the load is applied. Since substantially no uniform stress is applied, the durability can be improved. In addition, an angle adjusting step is formed on the body-side seating surface, and the angle θ formed by the engine-side seating surface with respect to the horizontal direction is at least less than 45 ° (θ <45 °). The spring constant in the vertical direction can be set larger than the spring constant in the direction,
Therefore, the phenomenon that the driver's seat vibrates in the vertical direction (so-called vertical bull), which occurs particularly in commercial vehicles (vehicles having a cab type driver's seat), can be effectively suppressed.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. 1 and 2 show an engine mount device 20 according to an embodiment of the present invention. FIG. 1 shows a side view of the engine mount device 20, and FIG. 2 shows a state in which the engine mount device 20 is mounted on a vehicle. Is shown.

As shown in FIG. 1, the engine mount device 20 includes an engine-side fitting 21, a body-side fitting 22, and a mount rubber 23 serving as an insulator.
And the like. The engine side bracket 21 has an engine side washer 24 and a protect cover 25 (not shown in FIG. 1 for convenience). The protect cover 25 is configured to extend in a flange shape toward the body-side metal fitting 22, and has an integrated structure by being welded to the engine-side washer 24. An implant bolt 26 and a positioning boss 27 are provided upright on the outer surface of the engine-side washer 24.

The stud bolt 26 is inserted into an insertion hole 28 formed in an engine side bracket 30 fixed to an engine (not shown), and a nut 29 is screwed thereto. The position of the positioning boss 27 is selected so as to correspond to the position of the positioning hole 31 formed in the engine side bracket 30. Therefore, while the positioning boss 27 is fitted in the positioning hole 31,
Is inserted into the insertion hole 28, and a nut 29 is screwed onto the stud 26, so that the engine-side bracket 21 is fixed to the engine-side bracket 30 while being positioned.

On the other hand, the body-side bracket 22 has a body-side washer 32 and an angle adjusting step 33, and the angle-adjusting step 33 is integrated with the body-side fitting 32 by welding. Have been. Both side portions of the body-side washer 32 are bent toward the engine-side metal fitting 21, and rubber stoppers 34 and 35 are provided at the distal ends thereof.
The rubber stoppers 34 and 35 are located inside the protect cover 25 provided on the engine-side metal fitting 21 and are configured to face the inner wall of the protect cover 25.

The angle adjusting step 33 has a flange 36 fixed to a frame-side bracket 37 provided on the vehicle frame. The flange 36 has an insertion hole 39 through which a fixing bolt 38 is inserted. Are drilled.
The angle adjusting step 33 has a triangular shape as viewed from the side as shown in FIGS. 1 and 2, and therefore, the flange 36 and the body side washer 32 are inclined by an angle indicated by an arrow θ2 in the figure. (Eg, θ2 ≒ 19)
°). The function and effect obtained by inclining the flange portion 36 and the body side washer 32 at an angle θ2 will be described later for convenience of explanation.

The mount rubber 23 (indicated by a satin finish in the figure) is formed in a cylindrical or quadrangular prism shape, and its engine side end is vulcanized and bonded to the inner surface of the engine side washer 24.
The body side end is vulcanized and bonded to the inner surface of the body side washer 32. Therefore, the mounting rubber 23
Is disposed between the engine-side washer 24 and the body-side washer 32.

The width of the mounting rubber 23 used in the present embodiment is indicated by the entire width (indicated by an arrow H in FIG. 1).
Has a substantially constant width, so that the engine-side seat surface 24 and the body-side seat surface 32 are arranged in parallel. In this way, by configuring the width dimension H of the mount rubber 23 (insulator) between the engine-side seating surface 24 and the body-side seating surface 32 to be uniform, the mounting rubber 23 can be mounted when a load is applied (when vibration is applied). 2
A substantially uniform stress without bias is applied to 3. Therefore,
The generation of excessive stress (strain) in the mount rubber 23 can be suppressed, and the durability of the mount rubber 23 can be improved.

The engine mount device 2 having the above configuration
0 is particularly advantageous for use in vehicles having a cab-type driver's seat (for example, commercial vehicles). Hereinafter, the reason will be described. As is well known, a vehicle having a cab-type driver's seat has a driver's seat above the engine, and the engine vibration is easily transmitted to the driver's seat. Therefore, in this cab type vehicle,
Mount rubber 2 provided on engine mount device 20
The setting of the spring constant 3 is important from the viewpoint of preventing vibration and noise.

As described above, the spring constant of the mount rubber 23 is determined by the horizontal spring constant Kx with respect to the horizontal direction (indicated by an arrow X in FIG. 2) and the vertical direction (indicated by an arrow Y in FIG. 2).
The vertical and horizontal spring constants Ky and the vertical spring constant Ky can be appropriately set to suppress vibration and noise in the driver's seat.

Conventionally, in setting the spring constant of the mount rubber in a cab type vehicle, the horizontal spring constant Kx and the vertical spring constant Ky are both set to be soft (ie, the spring constant is reduced). Was.
This is because the cab-type vehicle has the driver's seat located above the engine as described above, and thus the first consideration is to prevent transmission of engine noise to the driver's seat.

However, according to the experiments of the present inventor, as described above, the horizontal spring constant Kx and the vertical spring constant Ky
Although the transmission of the engine noise to the driver's seat can be prevented by setting both of them to be soft, it has been found that vibrations (so-called vertical bulls) trembling in the vertical direction occur in the driver's seat. The occurrence of the vertical bull is an uncomfortable vibration for the driver, and thus it is necessary to suppress the occurrence of the vertical bull. At the same time, it is necessary to prevent transmission of engine noise to the driver's seat.

Therefore, the present inventor has proposed a horizontal spring constant Kx and a vertical spring constant Ky which satisfy the above two requirements.
An experiment was performed to determine the combination of..., And the experimental result shown in FIG. 3 was obtained. In the figure, the vertical axis indicates the vertical spring constant Ky, and the horizontal axis indicates the horizontal spring constant Kx. In our experiments,
With the combination of the respective spring constants (Kx, Ky) indicated by the arrow A, the noise of both the upper and lower bulls and the driver's seat could be reduced most. It should be noted that a region B surrounded by a square in the drawing is a region where the occurrence of vertical bulls can be prevented and noise in the driver's seat can be reduced when tolerances are included.

From the experimental results shown in FIG. 3, the vertical spring constant Ky is set to be large (for example, Ky = 700 N / mm) in order to prevent the occurrence of vertical bulls and reduce the noise in the driver's seat.
It can be seen that the horizontal spring constant Kx should be set small (for example, Kx = 300 N / mm). That is, the vertical spring constant Ky is set hard, and the horizontal spring constant Kx is set.
Is set to be soft, it is possible to prevent the occurrence of vertical bulls and to reduce noise in the driver's seat.

Attention is now directed to FIG. 4 described above. In the engine mounting device 20 according to this embodiment, the width H of the mounting rubber 23 is set to be substantially constant throughout as described above, and therefore, the engine-side seat surface 24 and the body-side seat surface 32 are parallel. It is the structure arranged in. Therefore, assuming that the volume and the shape are substantially equal to those of the mounting rubber 6 used in the engine mounting apparatus 1 shown in FIG. 5, the mounting rubber 23 and the mounting rubber 6 should have substantially the same spring characteristics.

Therefore, by paying attention to the characteristics of the horizontal spring constant K1x and the vertical spring constant K1y indicated by solid lines in FIG. 4, the inclination can be set so that the vertical spring constant Ky is set large and the horizontal spring constant Kx is set small. When the area of the angle θ is obtained,
It can be seen that this condition is satisfied when the inclination angle θ is less than 45 °. That is, by setting the inclination angle θ, which is the angle between the engine-side seating surface 24 and the body-side seating surface 32, to be less than 45 °, it is possible to prevent the occurrence of vertical bulls and reduce the noise in the driver's seat.

However, if the inclination angle θ is simply set to less than 45 °, the structure of the engine mount device 10 shown in FIG. That is, the engine-side end surface 9a and the body-side end surface 9b of the mount rubber 9 must be non-parallel, and in this configuration, excessive stress is generated in the mount rubber 9 and durability is deteriorated as described above.

Therefore, in this embodiment, by providing the body-side metal fitting 22 with the angle adjusting step 33, the engine-side seating surface 24 and the body-side seating surface 32 are kept parallel (that is, the width dimension of the mount rubber 23). H), the angle θ1 formed by the engine-side seat surface 24 with respect to the horizontal direction X is 45 °.
Less than (° 1 <45 °).

As described above, in order to prevent the occurrence of vertical bulls and reduce noise in the driver's seat, it is not always necessary to make the engine-side seat surface 24 and the body-side seat surface 32 parallel to each other. By setting only the inclination angle θ1 at an angle of less than 45 ° (θ1 <45 °) with respect to the horizontal direction X, a horizontal spring that can prevent the occurrence of vertical bulls and reduce noise in the driver's seat can be achieved. A constant K1x and a vertical spring constant K1y can be realized. Therefore, according to the engine mount device 20 according to the present embodiment, it is possible to improve the durability of the mount rubber 23, prevent the occurrence of vertical bulls, and reduce the noise of the driver's seat.

As is clear from FIG. 2, the inclination angle θ
1 is an angle that depends on the angle θ2 of the angle adjustment step 33. Specifically, the angle θ3 of the position where the frame-side bracket 37 attaches the flange portion 36 (in the present embodiment, θ3
3 = 45 °), the inclination angle θ1 decreases when the angle θ2 of the angle adjustment step 33 is increased, and conversely, when the angle θ2 is increased, the inclination angle θ1 decreases.

Therefore, the inclination angle θ1 is determined by the angle adjustment step 3.
3 can be adjusted arbitrarily by simply adjusting the angle θ2 of the angle adjustment step 33, so that the engine mount device 20 can easily cope with various engines having different vibration characteristics. be able to. By the way, also in the engine mounting device 10 described above with reference to FIG. 6, the washer 4 of the engine-side bracket 2 has an inclination angle of less than 45 ° with respect to the horizontal direction X. For this reason, in the engine mount device 10, it is considered that there is a possibility of preventing generation of vertical bulls to some extent and reducing noise in the driver's seat.

Therefore, the present inventor conducted an experiment for determining the relationship between the spring constant and the inclination angle in the engine mount device 10. This result is shown by a dashed line in FIG. As shown in the drawing, the spring characteristic of the mount rubber 9 provided on the engine mount device 10 and having a non-uniform thickness is gentler than the spring characteristic of the mount rubber 23 used in the present embodiment, which is indicated by a solid line. Characteristic.

That is, the vertical spring constant K2y of the mount rubber 9 is larger than the vertical spring constant K1y of the mount rubber 23 in the region where the inclination angle is 45 ° or more, and conversely in the region where the inclination angle is 45 ° or less. It is getting smaller. The horizontal spring constant K2x of the mount rubber 9 is
In the region where the inclination angle is 45 ° or more, the mounting rubber 23 is used.
Is smaller than the horizontal spring constant K1x of
It is larger in the region of 5 ° or less.

Therefore, when attention is again paid to FIG. 3, the combination of the vertical spring constant Ky and the vertical spring constant Kx that can prevent the occurrence of vertical bulls and reduce the noise of the driver's seat is, for example, the vertical spring constant Ky. = 700 N / mm and horizontal spring constant Kx = 300 N / mm. For this reason, like the engine mount device 10, the vertical spring constant K2y and the horizontal spring constant Kx
In the mount rubber 9 having a spring characteristic with a small gradient of
It is impossible to realize the combination of the areas indicated by the arrow B in FIG. Therefore, the engine mount device 10 shown in FIG. 6 cannot prevent the occurrence of vertical bulls and reduce the noise in the driver's seat.

[0039]

As described above, according to the present invention, when a load is applied, a substantially uniform stress is applied to the insulator without bias, so that the durability can be improved. Further, since the vertical spring constant can be set to be larger than the horizontal spring constant of the insulator, it is possible to effectively suppress the phenomenon that the driver's seat vibrates vertically (especially vertical bull) especially in commercial vehicles. it can.

[Brief description of the drawings]

FIG. 1 is a side view of an engine mount device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which the engine mount device according to one embodiment of the present invention is mounted on a vehicle.

FIG. 3 is a diagram for explaining desirable vertical spring constant and horizontal spring constant required for mount rubber in a commercial vehicle.

FIG. 4 is a diagram illustrating a relationship between a spring constant of a mount rubber and an inclination angle.

FIG. 5 is a view for explaining a conventional engine mount device (part 1).

FIG. 6 is a view for explaining a conventional engine mount device (part 2).

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 engine mount device 21 engine-side bracket 22 body-side bracket 23 mount rubber (insulator) 24 engine-side washer 25 protect cover 26 stud bolt 27 positioning boss 28,39 insertion hole 29 nut 30 engine-side bracket 31 positioning hole 32 body-side washer 33 Angle adjusting step 34, 35 Rubber stopper 36 Flange 37 Frame side bracket 38 Fixing bolt

Claims (1)

[Claims] An engine-side fitting fastened to an engine, a body-side fitting fastened to a vehicle body, an engine-side seat provided on the engine-side fitting, and a body-side provided on the body-side fitting. An engine mount device comprising an insulator interposed between the seat surface and an insulator, wherein the insulator has a uniform width between the engine-side seat surface and the body-side seat surface, and By forming an angle adjusting step on the body side seating surface, an angle (θ) formed by the engine side seating surface with respect to a horizontal direction is at least less than 45 ° (θ <45 °). Characteristic engine mounting device.