JP3079954B2 - Suspension of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for supporting an internal combustion engine on a vehicle body, and more particularly, to a suspension device for an internal combustion engine having a variable spring constant with respect to displacement in the front-rear direction and left-right direction of the internal combustion engine. It is about.

[0002]

2. Description of the Related Art Conventionally, as a suspension device which elastically supports an internal combustion engine on a vehicle body and suppresses transmission of vibration generated from the internal combustion engine to the vehicle body, Japanese Patent Publication No. 5-23865 discloses a suspension device. Some have been disclosed. The suspension includes a first frame, a second frame, and an elastic body.
The second frame has a cylindrical shape extending vertically and is connected to the vehicle body via a bracket. The first frame is connected to the engine via a bracket. The elastic body is interposed between the second frame and the first frame to join them. And the second
The liquid is sealed in a liquid chamber surrounded by a frame, an elastic body, and the like. This suspension device is intended to reduce or restrict vibration by elastic deformation of an elastic body.

[0003]

However, in recent years,
It is desired that the spring constant in the direction perpendicular to the axis of the suspension device (the direction perpendicular to the center axis of the elastic body) be made different depending on the operation state of the internal combustion engine. For example, the spring constant is reduced in order to reduce the transmission of vibration in the roll direction during idling. That is, by making the spring soft at the time of idling, it is possible to easily absorb the vibration in the front-rear direction in the horizontally mounted internal combustion engine, and to easily absorb the vibration in the left-right direction in the vertically mounted internal combustion engine. Conversely, the spring constant is increased to suppress the displacement of the internal combustion engine due to inertial forces such as acceleration and deceleration of the vehicle and lateral movement. That is, by making the spring stiff when such an inertial force acts, it is possible to easily regulate the displacement in the front-rear direction in a horizontally placed internal combustion engine and to easily regulate the displacement in the left-right direction in a vertically placed internal combustion engine. .

However, in the conventional suspension device,
Only one spring constant in such a direction perpendicular to the axis can be set. Therefore, for example, if the spring constant is set small while giving priority to vibration absorption at the time of idling, the internal combustion engine is greatly displaced during acceleration / deceleration, and the acceleration / deceleration shock is increased. Contrary to this, if the spring constant is set to be large with priority given to acceleration or the like, vibration during idling cannot be sufficiently absorbed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to change a spring constant in a direction orthogonal to a center axis of an elastic body in accordance with an operation state of an internal combustion engine. It is an object of the present invention to provide a suspension system for an internal combustion engine, which makes it possible to achieve both suppression of vibration during idling and restriction of displacement of the internal combustion engine during acceleration and deceleration.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a suspension device provided on or near a roll shaft of an internal combustion engine for supporting the internal combustion engine on the vehicle body. A cylindrical body-side fixing member fixed to the engine, an engine-side fixing member fixed to the internal combustion engine side, a substantially conical shape, coupled to the vehicle-body-side fixing member at an outer peripheral portion thereof, and a top portion of the engine An elastic body coupled to the side fixing member; and changing means for changing a position of the engine side fixing member on the central axis of the elastic body according to an operation state of the internal combustion engine.

According to the above-mentioned means, the vibration of the internal combustion engine at idle or the displacement of the internal combustion engine due to the inertial force at the time of acceleration / deceleration of the vehicle is transmitted to the elastic body via the engine-side fixing member, where it is absorbed or restricted. You. At this time, the degrees of vibration absorption and displacement regulation are different depending on the spring constant of the elastic body. One of the factors that determine the spring constant is the deformed shape of the elastic body. That is, the spring constant is small when the elastic body is sheared, and large when the elastic body is compressed.
On the other hand, the shape of the elastic body differs depending on the position of the engine-side fixing member on the central axis of the elastic body.

Accordingly, if the position of the engine-side fixing member on the central axis of the elastic body is changed by the changing means according to the operating state of the internal combustion engine, the elastic body is deformed in the direction perpendicular to the central axis (compression / compression). It is possible to change the spring constant of (shear). For example, when the internal combustion engine is idling, the engine-side fixing member is moved in a direction to shear-deform the elastic body, and during acceleration or deceleration, the engine-side fixing member is moved in a direction to compressively deform the elastic body. Then, at the time of idling, the spring constant becomes small and the transmission of vibration in the roll direction of the internal combustion engine is suppressed. At the time of acceleration / deceleration or when the vehicle moves left and right, the spring constant becomes large, and displacement of the internal combustion engine due to inertial force is regulated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 3 and 4, an engine 12 as an internal combustion engine is disposed in an engine room 11 of the vehicle such that a crankshaft (not shown) extends substantially in the left-right direction. A transaxle 13 is drivingly connected to the left side of the engine 12. When torque around the crankshaft acts on them, the engine 12 and the transaxle 13
Attempt to rotate around 4.

The engine 12 and the transaxle 1
3 is supported on the vehicle body 19 by four mounts, a front mount 15, a rear mount 16, a left mount 17, and a right mount 18. The front mount 15 is arranged at the front of the transaxle 13, and the rear mount 16 is arranged at the rear of the transaxle 13. The left mount 17 is located on the roll shaft 14 on the side of the transaxle 13, and the right mount 18 is located on the roll shaft 14 on the side of the engine 12. The left and right mounts 17 and 18 constitute a suspension device and have the same configuration.

As shown in FIGS. 1 and 2, each of the left and right mounts 17 and 18 includes a vehicle body-side fixing member 21 and an engine-side fixing member 22.
And an elastic body 23. The vehicle-body-side fixing member 21 includes a substantially cylindrical body portion 24 having a bottom and an upper surface opened, and a cylindrical cylinder portion 25 having a smaller diameter than the body portion 24 and hanging down from a central portion of the bottom of the body portion 24. And a flange 26 formed on the outer peripheral surface of the main body 24. The vehicle-body-side fixing member 21 is fixed to the vehicle body 19 at the flange portion 26 by a fastening member (not shown) such as a bolt.

The engine-side fixing member 22 is composed of a fixing portion 28 and a connecting portion 29 which are spaced apart from each other, and a connecting portion 31 which connects the upper ends of the two 28, 29.
It is shaped like a letter. The engine-side fixing member 22 is fixed to the transaxle 13 at a fixing portion 28 by a fastening member (not shown) such as a bolt.

The elastic body 23 is made of rubber formed in a substantially conical shape, and is arranged so that its central axis 27 extends in the vertical direction which is a direction perpendicular to the roll shaft 14.
The outer peripheral portion 23a of the elastic body 23 is vulcanized and bonded to the inner peripheral surface of the main body 24, and the top 23b is vulcanized and bonded to the outer peripheral surface of the coupling portion 29. The elastic body 23 is
When the position of 9 on the central axis 27 changes, it can be elastically deformed in the vertical direction. With this elastic deformation, the spring constant in the direction perpendicular to the central axis 27 changes. For example, if the elastic body 23 is greatly extended vertically, the spring constant in the direction perpendicular to the axis decreases, and if the elastic body 23 is compressed, the spring constant in the direction perpendicular to the axis increases.

The cylinder portion 25 of the vehicle body-side fixing member 21
A piston 32 is slidably accommodated therein. A liquid chamber 33 is formed by the vehicle-body-side fixing member 21, the piston 32, the elastic body 23, and the connecting portion 29, and a liquid 34 is sealed therein. Piston 3 in cylinder part 25
Immediately below 2, an actuator 35 for reciprocating the piston 32 is fitted and fixed.

A controller (not shown) is electrically connected to the actuator 35. The controller drives and controls the actuator 35 in accordance with the operating state of the engine 12 and the running state of the vehicle at that time, and controls the piston 32. Move. Here, the controller moves the piston 32 to the uppermost position when the engine 12 is idling, and moves the piston 32 to the lowermost position when inertial force acts on the engine 12 during acceleration or deceleration. With the movement of the piston 32, the central axis 27 of the connecting portion 29
The upper position is changed, the shape of the liquid chamber 33 changes,
The elastic body 23 is deformed. The liquid chamber 33, the liquid 34, the piston 32, the actuator 35, and the controller constitute a changing unit.

According to the suspension described above, the engine 12
In the idle state, the piston 32 is held at the uppermost position of the cylinder section 25 as shown in FIG. The liquid 34 is pushed up by the piston 32, and the joint 29 vulcanized and bonded to the top 23 b of the elastic body 23 is held at the uppermost position on the central shaft 27. The liquid chamber 33 has a substantially frusto-conical shape with a high height, and accordingly the elastic body 23 has a substantially conical shape. At this time, the elastic body 23 extends the largest, and the spring constant in the direction perpendicular to the central axis 27 is the smallest. As shown by a dashed line in FIG. 5, the elastic body 23 bends relatively largely even when a small load is applied. Therefore, when idling, the engine 12
Roll movement around the center, and even if the longitudinal vibration accompanying the movement is applied to the left and right mounts 17 and 18,
The transmission of the vibration is effectively reduced by the shear deformation of the elastic body 23 having the reduced spring constant.

On the other hand, when the vehicle (engine 12) is accelerated or decelerated, as shown in FIG.
Is moved to the lowest position. With the downward movement of the piston 32, the connecting portion 29 moves to the lowermost position on the center shaft 27, and the shape of the liquid chamber 33 changes. Elastic body 2
3 is compressed and deformed into a substantially conical shape with a low height, and the spring constant in the direction perpendicular to the central axis 27 becomes the largest. As shown by the solid line in FIG. 5, the elastic body 23 does not bend unless a large load is applied compared to the idle state.
Therefore, even if an inertial force due to acceleration / deceleration is applied to the engine 12 and the transaxle 13, their displacement is restricted by the elastic body 23 being compressed and deformed.

As described above, by changing the position of the coupling portion 29 on the central axis 27 by reciprocating the piston 32, the spring constant in the direction perpendicular to the central axis 27 (front-back direction) can be changed. It becomes possible. Therefore, when idling, the spring constant in the same direction is reduced to suppress transmission of vibration in the roll direction, and during acceleration / deceleration, the spring constant in the same direction is increased to increase the engine 12 and transaxle 13.
, And acceleration / deceleration shock can be reduced.

Further, the position of the connecting portion 29 can be changed only by moving the piston 32 up and down, and a complicated mechanism is not required. Further, since the liquid 34 and the elastic body 23 interposed between the coupling portion 29 and the piston 32 can change the overall shape when a load is applied, the piston 3
There is no hindrance to the displacement of the connecting portion 29 at the time of the two stop.

The present invention can be embodied in another embodiment shown below. (1) The present invention relates to an engine 12 and a transaxle 1
3 can also be applied to a so-called vertical type engine in which the roll shaft 14 is arranged to extend in the front-rear direction of the vehicle. For example, in the case where a pair of front mounts is arranged near the left and right sides of the roll axis in the engine and a rear mount is arranged on the roll axis in a transaxle at the rear of the engine, the present invention is also applied to both front mounts. Also applicable to In this case, lateral displacement of the engine or the like due to inertial force such as lateral movement of the vehicle can be suppressed.

(2) The piston 32 may be changed so as to reciprocate in a direction other than up and down, for example, in a horizontal direction. (3) In the above-described embodiment, the position of the coupling portion 29 on the central axis 27 is changed in the two operating states of the engine 12 (at the time of idling and at the time of acceleration / deceleration). May be set, and the position may be changed according to each operation state.

(4) At least one of the left mount 17 and the right mount 18 in the above embodiment may be provided between the engine 12 and the vehicle body 19 instead of between the transaxle 13 and the vehicle body 19. .

While the embodiments of the present invention have been described above, technical ideas other than the claims that can be grasped from each embodiment will be described below together with their effects. (A) In the suspension device according to claim 1, the changing means is slidably accommodated in a vehicle body-side fixing member, and a piston that forms a liquid chamber between the elastic body and the vehicle body-side fixing member. A suspension system for an internal combustion engine, comprising: a liquid sealed in the liquid chamber; an actuator for reciprocating the piston; and a controller for driving and controlling the actuator according to an operation state of the internal combustion engine. With this configuration, it is possible to change the position of the coupling portion on the central axis according to the operating state with a simple configuration.

[0024]

As described above in detail, according to the present invention, the cylindrical body-side fixing member and the engine-side fixing member are connected by a substantially conical elastic body, and the operating state of the internal combustion engine is changed by the changing means. The position of the engine-side fixing member on the central axis of the elastic body is changed accordingly. For this reason, the spring constant in the direction orthogonal to the center axis of the elastic body can be changed according to the operating state of the internal combustion engine, suppressing vibration during idling of the internal combustion engine and regulating displacement of the internal combustion engine during acceleration and deceleration. Can be achieved at the same time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a left (right) mount when an engine is idle.

FIG. 2 is a cross-sectional view of a left (right) mount during acceleration and deceleration of the engine.

FIG. 3 is a schematic view of a state in which an engine and a transaxle are supported by a vehicle body, as viewed from the rear of the vehicle.

FIG. 4 is a schematic view of a state in which an engine and a transaxle are supported on a vehicle body as viewed from above.

FIG. 5 is a characteristic diagram showing a correspondence relationship between a load applied to an elastic body and an amount of displacement.

[Explanation of symbols]

12: engine as internal combustion engine, 14: roll shaft, 1
9: vehicle body, 21: vehicle body side fixing member, 22: engine side fixing member, 23: elastic body, 23a: outer peripheral portion, 23b: top portion, 2
7: central axis, 28: fixed part, 29: coupling part, 32: piston, 33: liquid chamber, 34: liquid, 35: actuator.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-169140 (JP, A) JP-A-56-43029 (JP, A) JP-A-59-140935 (JP, A) JP-A-59-140935 159444 (JP, A) Japanese Utility Model Showa 57-176322 (JP, U) Japanese Utility Model Showa 57-194824 (JP, U) Japanese Utility Model Showa 62-128247 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) F16F 13/26 B60K 5/12 F16F 15/08 F16M 7/00

Claims (1)

(57) [Claims] 1. A suspension device provided on or near a roll shaft of an internal combustion engine and supporting the internal combustion engine on a vehicle body, comprising: a tubular vehicle-body-side fixing member fixed to the vehicle body; An engine-side fixing member fixed to the engine side; an elastic body having a substantially conical shape, coupled to the vehicle-body-side fixing member at an outer peripheral portion thereof, and coupled to the engine-side fixing member at a top portion; Changing means for changing a position of the elastic body on the central axis of the elastic body in accordance with an operation state.