JPH0227533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine mount for a vehicle, and more particularly to an engine mount that can effectively reduce front shake of a vehicle.

[Prior Art] When a vehicle is running at high speed, the front part of the frame is caused to resonate and vibrate due to the excitation force input from the suspension, resulting in so-called front shake. Conventionally, therefore, countermeasures have been taken, such as increasing the rigidity of the frame or attaching a mass to the tip of the frame.

[Problems to be Solved by the Invention] However, none of these measures has been effective, and there is a problem in that the weight of the vehicle increases.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and it is an object of the present invention to provide an engine mount that can effectively reduce front shake and does not increase vehicle weight.

[Means for Solving the Problems] The configuration of the present invention will be explained with reference to FIG. 1. The thick rubber elastic body 1 is in the shape of a container, on which the engine E is mounted and which forms the chamber wall of the main fluid chamber A. are doing. The thin rubber elastic body 2 is freely deformable and constitutes the chamber wall of the sub-liquid chamber B. The partition plate 3 has both liquid chambers A,
It has a liquid communication hole 514 that partitions the liquid chambers A and B and allows the sealing liquid to freely flow between the liquid chambers A and B with substantially no resistance to flow. The liquid flow hole 5
A control means 5 closes the valve means 4 to seal the main liquid chamber A according to the running condition of the vehicle.

The expansion elastic modulus of the thick rubber elastic body 1 is set such that when the main liquid chamber A is sealed, the device spring and the mass of the engine constitute a dynamic damper having a predetermined natural frequency. .

Further, the partition plate 3 is provided with a cylindrical first stopper 31 so as to surround the liquid flow hole 514 and protrudes into the main liquid chamber A, and the thick rubber elastic body 1 is provided with a cylindrical second stopper 31. 7 is provided, the protruding tip of which faces the plate surface of the partition plate 3 at a predetermined interval, and the inner circumferential surface thereof faces the outer circumferential surface of the first stopper 31 at a predetermined interval.

[Operations and Effects] During normal running, the valve means 4 is kept open. In this state, the sealing liquid freely flows between the two liquid chambers A and B in response to the vibration input, and substantially no acting force is generated. Therefore, vibrations are absorbed and reduced by the rubber elastic body 1.

When the vehicle is running in a state where front shake is likely to occur, for example, when driving at high speed, the control means 5 closes the valve means 4 to seal the main liquid chamber. This results in
High internal pressure is generated in the main liquid chamber A in response to vibration input, and the spring force generated in the main liquid chamber A whose chamber wall is the thick rubber elastic body set to a predetermined expansion modulus and the main liquid chamber A dynamic damper with a natural frequency determined by the mass of engine E supported by engine A is constructed.

The natural frequency of this dynamic damper is made to match the frequency of front shake, and the front shake is effectively reduced by anti-resonance.

If excessive vertical vibration is input, the second stopper 7 will come into contact with the surface of the partition plate 3, and if excessive horizontal vibration is input, the second stopper 7 will come into contact with the outer peripheral surface of the first stopper 31. In contact with the thick rubber elastic body 1
Excessive deformation of the material is prevented.

These stoppers 31 and 7 are installed compactly inside the mount, and also protect the valve means 4 well.

According to the present invention, there is no need to take measures such as increasing the rigidity of the frame or attaching a mass, so an increase in vehicle weight can also be avoided.

[Example] Figure 1 shows the entire cross section of the engine mount,
FIG. 2 shows a half sectional view of the mount seen from below.

In FIG. 1, a rubber elastic body 1 is a container body having a thick cylindrical side wall that gradually expands downward, and has a flat upper surface joined to an upper plate 6. The rubber elastic body 1 is filled with liquid to form a main liquid chamber A.
A cylindrical stopper plate 7 serving as a second stopper is provided on the lower surface of the center of the upper plate 6, and the rubber elastic body 1 covers the surface of the stopper plate 7.

The lower end surface of the rubber elastic body 1 is joined to the upper half of a cylindrical side plate 8 having an S-shaped cross section. The peripheral edges of the partition plate 3, the thick rubber elastic body 2 which is the wall of the sub-liquid chamber B, and the bottom plate 9 are fixed to the lower half of the side plate 8 from above by caulking. The center portion of the partition plate 3 has a cylindrical shape that projects upward and serves as a stopper portion 31 serving as a first stopper, and the stopper portion 31 is located within the stopper plate 7.

Therefore, the lower end of the stopper plate 7 is connected to the partition plate 3.
The inner circumferential surface thereof faces the outer circumferential surface of the stopper portion 31 at a predetermined interval.

The center of the bottom plate 9 is upwardly convex, and a control electromagnet 5 is provided on the upper surface of the center. The electromagnet 5 has a cylindrical case-shaped yoke 51, and a coil winding 52 is wound within the yoke 51 around a rod 511 that projects from the center. Yoke 5 above
1 has a threaded portion 512 protruding from the center of the lower surface passed through a hole in the bottom plate 9 and fixed with a nut 91. The upper end of the yoke 51 is made to protrude toward the outer circumference as a flange portion 513, and the flange portion 5
An O-ring 53 provided on the outer circumference of the partition plate 13 is brought into liquid-tight contact with the inner circumference of the stopper portion 31 of the partition plate 3. The flange portion 513 is provided with liquid flow holes 514 at a plurality of locations on the circumferential surface to allow the sealing liquid to freely flow therethrough.

The upper end of the rod 511 has a small diameter, and the valve plate 4 is fitted into the upper end of the rod 511 so as to be vertically movable. The valve plate 4 is supported above the liquid flow hole 514 by a coil spring 54 installed inside the electromagnet 5, and is connected to the coil winding 5 via a lead wire 55.
When the valve plate 2 is energized, the valve plate 4 is attracted and seals the liquid flow hole. The lead wire 55 is connected to, for example, a vehicle speed detection device, and the device energizes the electromagnet 5 at a vehicle speed higher than that at which front shake is likely to occur. In addition,
The thin rubber elastic body 2 has its center portion joined to the outer periphery of the electromagnet 5.

The upper plate 6 projects outward at a radially symmetrical position,
The engine E (FIG. 1) is fixed through a mounting hole 611 provided in the protrusion 61 (FIG. 2). The engine mount is fixed to the vehicle frame by bolts 92 provided upright on the bottom plate 9.

Normally, the electromagnet 5 is not energized, and the valve plate 4 is positioned above the liquid flow hole 514 to open it, as shown. In this state, the sealing liquid can freely flow between the liquid chambers A and B through the liquid flow hole 514, and the sealing liquid does not substantially generate any acting force. Therefore, engine vibrations are absorbed and reduced by the rubber elastic body 1.

When a vehicle starts running at high speed, the vehicle frame bends and vibrates, causing so-called front shake. This is near the resonance point of the above frame (for example, 15
Hz) occurs in a relatively narrow vibration range. Here, when the electromagnet 5 is energized, the liquid flow hole 514
is sealed by the valve plate 4, and a large internal pressure is generated in the sealed main liquid chamber A along with vibration input. Due to the increase in internal pressure, the spring force of the main liquid chamber A whose chamber wall is the thick rubber elastic body 1 set to a predetermined expansion elastic modulus increases, and the main liquid chamber A and the engine E supported therein increase. becomes a dynamic damper with a natural frequency approximately equal to the resonant frequency of the frame. Thus, the engine mount and engine E
Due to the anti-resonance action of the dynamic damper, resonance vibration of the vehicle frame is generated and front shake is reduced.

Note that if excessive vertical vibration is input, the stopper plate 7 will come into contact with the plate surface of the partition plate 3, and
In response to excessive horizontal vibration, the stopper plate 7 comes into contact with the outer peripheral surface of the stopper part 31, and the thick rubber elastic body 1
Excessive deformation of the material is prevented. The stopper portion 31 and the stopper plate 7 are installed compactly inside the mount. Further, the valve plate 4 is surrounded by a stopper portion 31 and is protected from interfering with other mount components.

If a sealing rubber layer 56 is formed directly on the outer periphery of the flange portion 513 of the electromagnet 5 as shown in FIG. 3 instead of the O-ring 53 in the above embodiment, the number of parts can be reduced and the labor of installation can be omitted. .

[Brief explanation of drawings]

Fig. 1 is an overall sectional view of the engine mount, and a sectional view taken along the second line I-I, Fig. 2 is a half plan view of the engine mount seen from below, and Fig. 3 shows another embodiment. It is a sectional view of the main part. DESCRIPTION OF SYMBOLS 1... Thick rubber elastic body, 2... Thin rubber elastic body, 3... Partition plate, 31... Stopper part (first stopper), 4... Valve plate (valve means), 5... Electromagnet (control means), 514...liquid flow hole, 7...stopper plate (second stopper), E...engine.

Claims (1)

[Claims] 1 A container-shaped thick rubber elastic body in which the engine is placed, a main liquid chamber whose chamber wall is the rubber elastic body, a sub-liquid chamber whose chamber wall is a freely deformable thin rubber elastic body, and the main liquid chamber. A partition plate provided with a liquid flow hole that partitions the liquid chamber and the sub-liquid chamber and allows the sealed liquid to freely flow between the liquid chambers with substantially no flow resistance, and a valve means that opens or closes the liquid flow hole. a control means for closing the valve means to seal the main liquid chamber according to the running condition of the vehicle; and a cylinder provided on the partition plate so as to surround the liquid flow hole and protruding into the main liquid chamber. a first stopper having a shape, and a first stopper that is integrally provided with the thick rubber elastic body, protrudes into the main liquid chamber, and has a tip facing the plate surface of the partition plate at a predetermined interval, and an inner circumferential surface of the first stopper. a second cylindrical stopper facing the outer peripheral surface at a predetermined interval, and such that the device spring when the main liquid chamber is sealed forms a dynamic damper with a predetermined natural frequency together with the mass of the engine. An engine mount for a vehicle, characterized in that the thick rubber elastic body has an expanded modulus of elasticity.