FR2465927A1 - VIBRATION ABSORBING SYSTEM FOR USE IN A VEHICLE - Google Patents

Abstract

THE INVENTION RELATES TO A VIBRATION ABSORPTION SYSTEM FOR USE WITH A VEHICLE HAVING A BODYWORK AND A VIBRATION GENERATING DEVICE. ACCORDING TO THE INVENTION, IT INCLUDES A MEANS 26 OF ABSORPTION OF VIBRATIONS PROVIDED BETWEEN THE BODYWORK AND THE VIBRATION GENERATOR DEVICE FOR DAMPING THE VIBRATIONS OF THE GENERATOR DEVICE, THE MEANS OF ABSORPTION OF VIBRATIONS HAVING A MEANS 30, 31, 35, 36 , 39 TO VARY ITS DAMPING CHARACTERISTICS OF VIBRATIONS IN RESPONSE TO AN ELECTRIC SIGNAL; AND A SIGNAL GENERATOR PRODUCING THIS ELECTRIC SIGNAL IN RESPONSE TO A PREDETERMINED MOTOR OPERATING CONDITION. THE INVENTION APPLIES IN PARTICULAR TO THE AUTOMOTIVE INDUSTRY

Description

The present invention generally relates to a

  vibration-absorbing system to dampen vibra-

  a device which produces it as an internal combustion engine or a drive system connected to the engine, and more particularly relates to a vibration absorbing means arranged to connect the vibration generating device and the bodywork.

of the vehicle.

  Vehicles such as motor vehicles are equipped with internal combustion engines and drive systems connected to the engine, which produce vibrations whose frequencies are variable according to the operating conditions of the engine. Such vibrations are transmitted to the vehicle body and radiate, contributing to the increase of the vehicle noise. In addition, the vibrations can be amplified when they are transmitted to the body, to emit the noise and amplified. From this point of view, a device that effectively absorbs the vibrations of the motor or the drive system has long been needed, however, it is difficult to obtain such an apparatus because the vibration frequencies vary over a wide range of times.

  range according to the operating conditions of the motor.

  A vibration absorbing system according to the present invention is installed in a vehicle having a body and a vibration generating device such as a motor. The vibration absorbing system is comprised of a vibration absorbing means disposed between the body and the vibration generating device for damping vibration of the vibration generating device. This absorption means comprises a device for varying its vibration damping characteristics in response to an electrical signal produced at a signal generator, in response

  to a predetermined condition of engine operation.

  Therefore, the vibration damping characteristics of the absorption means are variable in response to the operating conditions of the engine, and these vibrations can thus be effectively damped over a wide range of engine operating conditions, which greatly contributes to the reduction of vehicle noise. The invention will be better understood, and other purposes, features, details and advantages thereof will become apparent

  more clearly during the explanatory description which

  will be followed with reference to the schematic drawings

  given only as illustrative examples

  embodiments of the invention and in which - Figure 1 is a schematic illustration of a

  motor vehicle equipped with a traditional means of absorbing

  vibration; - Figure 2 is a schematic illustration of the proximity of a set of a rear axle equipped with a traditional means of vibration absorption; FIG. 3 is an enlarged section of an example of a traditional means of absorbing vibrations; FIG. 4 is an enlarged section of another example of a traditional means of absorbing vibrations; FIG. 5 is a schematic illustration of a motor vehicle equipped with a first embodiment of the vibration absorption system according to the present invention; FIG. 6 is an enlarged section of the first embodiment of the system of FIG. 5; Fig. 7 is an enlarged section of a second embodiment of the vibration absorbing means of the system of Fig. 4; and FIG. 8 is a schematic illustration of another application of the vibration absorption means of

Figure 7.

  To facilitate the understanding of this

  In the first place, reference will first be made to traditional means of absorbing vibrations in FIGS. 1 to 4. In vehicles, and in particular motor vehicles equipped with motors, the installation of the motor or other drive unit connected to the engine is studied relative to the body of the vehicle to prevent vibrations-the engine to be transmitted to the body, which transmitted vibrations can be so amplified. From this point of view, as can be seen in FIG. 1, the engine 1 is supported by assemblies 2 on a frame 3 of the chassis, and in addition, the upper section (for example the proximity of a carburettor 1a). of the engine 1 is connected by a vibration absorption means 5 to a member 4 of the body. In addition, as can be seen in FIG. 2, an end reducer 6 or the assembly of a rear axle is connected by the other means of absorbing vibrations.

8, to the frame 7 of the frame.

  An example of a traditional means of vibration absorption is shown in Figure 3, which includes

  rings 10 formed at both ends of a rod of

  9. Elastic members 12 are arranged inside the rings 10 to connect these rings to sleeves 11 which are attached to the body or to a vibration-generating device such as the motor 1 or

the final gearbox 6.

  FIG. 4 shows another example of a traditional means of vibration absorption, which comprises a rod 13 having, at one end, a piston 15 and connected, at its other end, to the ring 10, and another rod 14 having at one end a cylinder 16 and connected by its

  other end, to the second ring 10. A hydraulic fluid

  The piston 15 has an orifice 17 for restricting the flow of hydraulic fluid therethrough. With this arrangement, the vibrations transmitted to this vibration absorbing means can be damped by virtue of the flow resistance of the

  hydraulic fluid passing through the orifice-17.

  As will be noted, the depreciation characteristics

  Such conventional means of vibration absorption are inevitably determined over a certain range, by the viscosity of the fluid, the diameter of the orifice 17, and the like, and therefore they are not variable in response to the operating conditions of the engine. like its speed, or the cruising conditions of the vehicle. From this point of view, the damping characteristics of the vibration absorbing means are established to absorb the low frequency vibrations from the point of view of improving the comfort of driving the vehicle, the high frequency vibrations produced during operation of the vehicle. high speed motor can not be absorbed by the vibration absorbing means, which high frequency vibrations are transmitted to the bodywork, producing considerable noise and discomfort in the passenger compartment

of the vehicle.

  Taking into account the above description of the traditional means of vibration absorption, reference will now be made to FIGS. 5 to 8 of the drawings, and more particularly to FIG. 5, which is illustrated in A, a preferred embodiment of the system of FIG. absorption of vibrations according to the invention, which is installed in a motor vehicle. The motor vehicle comprises a body 20 which contains a suspension crossmember 21 supported by suspensions, and a panel 23. An internal combustion engine 24 is supported on the suspension crossmember 21 by assemblies 25 formed of an elastic material. A vibration absorbing means 26 forming part of the vibration absorbing system A is disposed between the body panel 23 and the upper section of the engine 24 or the proximity of a carburettor to connect the body panel and the body. upper section of the engine. Figure 6 shows the detailed construction of the medium

  of vibration absorption 26 which consists of

  first and second rods 32 and 33 whose axes are aligned.

  The first rod 32 has at one end a piston 30 and is integrally connected at its other end to an annular member 10 '. The annular member 10 'is connected by a resilient member 12' to a sleeve 11 'through which the vibration absorbing means 26 is connected to the upper section of the motor. The piston 30 has an orifice 35 whose axis is parallel to that of the rod 32. The piston is movably disposed in a hydraulic cylinder 31 which is integrally formed with one end of the rod 33 which is integrally connected by its other end, to another ring 10'a. The housing 10'a is connected by an elastic member 12'a to the sleeve member 11'a by which the vibration absorbing means 26 is firmly fixed

  at the upper section of the panel 23 of the bodywork.

  The cylinder 31 is filled with a hydraulic fluid and is separated into two chambers 3a and 31b which communicate

  one with the other through the orifice 35 formed in the piston.

  In addition, the cylinder 31 comprises a passage 36 of the fluid through which the two chambers 31a and 31b communicate in order to allow the hydraulic fluid to flow through the

  passage 36 from chamber 31a to chamber 31b and reverse

  according to the reciprocal movement of the piston 30. The means

  vibration absorption device 26 comprises an electromagnetic valve

  magnet 39 which comprises a solenoid37 and a movable valve member 38 for closing the passage 36 to

  block communication between rooms 31a and 31b.

  The electromagnetic valve 39 is constructed and arranged so that (1) the bias is urged downward in FIG. 6 by a spring 60 to close the passage 36 when the solenoid 37 is de-energized and (2) the member 38 is moved upwards in FIG. 6 against the biasing of the spring to open the passage of the fluid in order to establish the communication between the chambers 31a and 31b when the

solenoid is excited.

  As illustrated in FIG. 5, the solenoid 37 of the solenoid valve is electrically connected to a battery 27 by conductors 28. A switch 29 is disposed in the conductor 28 which connects the solenoid 37 to the positive terminal of the battery 27. This switch 29 serves as a signal generator for applying an electrical signal or an electric current to solenoid 37 of the solenoid valve when a running condition of the motor reaches a predetermined level. It will be understood that the solenoidb37 is energized when it receives the electrical signal from the switch 29. In this case, the switch 29 is in connection with a motor speedometer, and is arranged to be closed or passing to produce the electrical signal when the motor speed exceeds a predetermined level, that is, when the engine operating condition reaches the level at which there is vibration at a frequency above a predetermined level. The switch 29 may also be connected to a throttle device of the vehicle and arranged to produce the electrical signal when the opening

  throttle valve exceeds a predetermined level.

  The operating mode of the absorption system

  vibration of Figures 5 and 6 will now be described.

  When the motor 24 supported by the fixtures by the suspension cross member 21 operates, it vibrates because of its torque variations. In the low speed range of the engine, particularly where the frequency of vibration due to torque variations matches or resembles the natural frequency of the vehicle which is

  determined by the motor 24 and the assemblies 25, the switching

  29 does not close and the solenoid 37 of the electromagnetic valve of the vibration absorption means 26 remains un-energized. Therefore, the organ of vane

  38 is biased downwardly by the spring 60 to maintain

  For example, the fluid in the chambers 31a and 31b passes through the orifice 35 of the piston without passing through the passage 36. In this state, the vibration absorption means is suitable for damping the vibrations. relatively low vibration frequencies, which suppresses the increase in motor vibration

because of the variations of the couple.

  However, as the vibration frequency increases, the fluid is forced to pass through the port 35 of the piston more rapidly until the movement of the piston due to vibration and thus fluid through the orifice, surpasses the the maximum rate at which the fluid can pass through the orifice. At vibration frequencies above this range, the piston 30 is no longer used to absorb vibrations. Therefore, in the vibration absorption system according to the invention, when the engine speed increases and exceeds the predetermined level,

  the switch 29 closes to provide electric current

  than solenoicb, 37, to excite it in order to shift the organ

  38 up on the drawing to open passage 36.

  As a result, the fluid in the two chambers 31a and 31b can pass through the passage 36 with the movement of the piston

  to decrease the resistance of the fluid against the piston.

  Fluid flows through port 35 into the piston, and also through a second port defined by valve member 38 and its seat. This arrangement reduces the effect of the port 35 of the piston by providing another path for the fluid between the chambers 31a and 31b, thereby maintaining the piston orifice effective to restrict the flow of fluid therethrough. Chix, who are uncompromising in this regard, will readily note that in doing so the range of effective vibration absorption frequencies is high. In this state, the vibration absorbing means 26 is suitable for damping relatively high vibration frequencies. Therefore, the high frequency vibrations of the motor 24 are absorbed in the vibration absorbing means 26 and therefore can not be transmitted to the vehicle body 20, so there is

  noise reduction in the passenger compartment of the vehicle

  cule. Figure 7 shows a second embodiment of the

  vibration absorption means 26 whose characteristics

  damping of vibrations vary in virtue. electromagnetic force. The vibration absorbing means 26A comprises a rod 40 integrally connected at one end to the bagoe 10 'and having at its other end a cylinder 41. The cylinder 41 has on its inner surface a bearing section 44 to hold one end of a plunger 43 sliding. The plunger 43 is integrally connected at its other end to a rod 42 which is slidably received by a bearing section

  44 'disposed in the cylinder 41. The rod 40 is integrally

  connected to the ring 1O'a. The plunger 43 may have a reciprocal movement in the cylinder 41. The movement of the plunger is limited by resilient abutments 46, 46 'placed in the cylinder near the respective bearing sections 44, 44'. The enlarged section 48 of the plunger 43 has a flat section in sliding contact with a flat surface of an iron core 47 forming part of an electromagnet. The core 47 is constructed and arranged to

  to be mapped when a solenoid 45 surrounding it is excited.

  The second embodiment operates in a manner identical to the first. The absorption range of the vibration frequencies is determined by the force opposing the reciprocal movement of the plunger 43. This force is determined by the mass of the plunger multiplied by the acceleration (F = ma). With the increase of the

  frequency of vibration, there is an increase in the acceleration

  tion. Therefore, the force against the movement of the plunger must be reduced as in the first embodiment by providing another path for the fluid, reducing the electromagnetic force that keeps the plunger stationary. Therefore, at low frequencies, solenoid 45 is passing at high frequencies it is no

passing.

  With the vibration absorbing means 26A thus arranged, when the solenoid45 is not supplied with electric current, the plunger 43 can move relatively

  freely in the cylinder 41, only with a resistance

  this sliding against the bearing sections 44 and 44 '.

  Therefore, in this state, the vibration absorbing means 26A is suitable for damping vibrations

at relatively high frequencies.

  When the solenoid 45 is excited by means of an electric current, a magnetic field is formed between the section of the iron core 47 and the enlarged section 48. This magnetic force of the iron core 47 creates a resistance against the movement of the plunger 43 by report to him. As a result, in this state, the vibration absorbing means 26A becomes suitable for damping relatively low vibration frequencies. It will be understood that when this vibration absorbing means 26A is used in place of the absorption means 26 of the first embodiment of FIG. 6, it is necessary to use a switch 29 designed to open when the motor speed exceeds the predetermined level and to close

  at engine speeds below the predetermined level.

  While only the mode of installation of the vibration absorbing means 26 or 26A, where the rings 10 'or 10'a are connected to the motor 24 and to the body member 23, respectively, has been illustrated and described. it will be noted that the inverted mode of installation is possible, where the rings 10 'and 10'a are connected to the body of the

  body 23 and motor 24, respectively.

  FIG. 8 illustrates another installation of the vibration absorption system according to the invention, the vibratory absorption means of the second embodiment being used to absorb the vibrations of an assembly of a rear axle 50 or a reduction gear final. In this case, the vibration absorbing means of the type of FIG. 7 is illustrated as being used, although that of the type shown in FIG. 6 is also valid. The vibration absorption means 26A is disposed between the entire rear axle 50 and a floorboard 51. In this case, the rod 40 is connected to the panel 51 and

  the rod 42 is connected to the assembly of the rear axle 50.

  Otherwise, the rod 40 may be connected to the assembly 50 and the rod 42 to the panel 51. The panel 51 is supported by a frame 54 of the body to which a leaf spring 52 is securely attached. A rear axle housing 53 connected to the assembly 50 is suspended by the leaf spring 52. A damper 55 is disposed between the frame 54 and the leaf spring 52. The solenoid 45 of the vibration absorbing means 26A is electrically connected to the battery 27 by the switch 29A arranged to be closed in order to supply the solenoid 45 with electric current when the throttling opening exceeds a

predetermined level.

  In the arrangement illustrated in FIG. 8, tire vibrations are usually produced in the vibration generating system including the leaf spring 52, and the like by the engine torque variations. However, under a condition of high load engine operation where motor torque changes are greater, switch 29A closes to make the vibration absorbing means 26A effective to dampen relatively low vibration frequencies so to remove the aforementioned bandage vibrations. At other operating conditions of the motor, the switch 29A is open to energize the solenoid 45 and therefore the vibration absorbing means 26A is made suitable for damping relatively high vibration frequencies. This prevents vibrations due to an uneven surface of the road or transmitted by a drive train to be transmitted to the bodywork,

  thus helping to reduce noise.

  In general, the automobile masters and the drive devices which are connected to them exhibit resonance phenomena under these particular operating conditions of the engine, such as particular engine speeds, particular positions of the throttle valve or the throttle valve. -vanne, and cruising speeds of the vehicle. However, it will be apparent from the foregoing that the particular vibrations resulting from such resonance phenomena can be suppressed over a wide range of engine operation.

  by the vibration absorption system according to the invention.

  As will have been noted. upon reading the foregoing, according to the present invention, a vibration absorbing means is arranged for connecting a vehicle body and a vibration generating device such as a motor or a driving device connected to the engine, which absorption means is provided with a device for varying its vibration damping characteristics in response to the operating conditions of the engine. Therefore, vibration transmission from the vibration generating device to the body is effectively prevented over a wide range of engine operating conditions, thereby achieving

a reduction of the engine noise.

  Of course, the invention is in no way limited to the embodiments described and shown which have been given only by way of example. In particular, it comprises all the means constituting technical equivalents of the means described, as well as their combinations if they are executed according to his spirit and

  in the context of protection as claimed.

Claims (14)

R E V E N D I C A T I 0 N S   A vibration absorbing system for use with a vehicle having a body and a vibration generating device, characterized in that it comprises - vibration absorbing means (26; 26A) disposed between said body and said apparatus vibration generator for damping vibrations of said   generating device, said vibration absorption means   having means for varying its vibration damping characteristics in response to an electrical signal; - a signal generator (29% 29A) to produce   said electrical signal in response to a predetermined condition engine operation.   2. System according to claim 1 characterized in that the aforementioned vibration absorption means comprises a cylinder (31) filled with a hydraulic fluid and connected to the vehicle body or the vibration generating device, and a piston (30). ) movable in said cylinder to separate the interior thereof in first and second chambers (31a, 31b), said piston having an orifice 35 putting said chambers in communication said piston being connected to the vibration generating device or the bodywork of the vehicle,   and in that said vibration absorbing means comprises   means (36) defining a fluid passage through said first and second chambers and an electromagnetic valve (39) having a movable valve member (38) closing said passage when its solenoid   (37) is energized when it is supplied with electric power.   3. System according to claim 2, characterized in that the aforesaid signal generator comprises a switch (29) electrically connected to the above solenoid of the aforementioned electromagnetic valve and which is closed to supply the electrical current to said solenoid when the value of a engine operating parameter exceeds a predetermined level.   4. System according to claim 3 characterized in that the aforesaid vibration absorption means comprises a first rod (32) integrally connected to the aforesaid piston and connected to the aforementioned vibration generating device and a second rod (33) integrally connected to the cylinder aforementioned and connected the bodywork of the vehicle.   5. System according to claim 4 characterized in that the aforementioned vibration generating device is an internal combustion engine (24) mounted on the body of the vehicle.   6. System according to claim 5 characterized in that the engine operation parameter is his speed.   7. System according to claim 1, characterized in that the aforesaid vibration absorption means comprises a cylinder (41) connected to the vehicle body or the vibration generating device, and a plunger (43) slidably disposed in said cylinder and connected to the vibratim generating device or the vehicle body, and in that said vibration absorbing means comprises an electromagnet (47) integrally connected to said cylinder and which attracts said plunger when its solenoid (45) is excited in   being supplied with electric current.   8. System according to claim 7 characterized in that the aforesaid signal generator (29) consists of a switch electrically connected to the above solenoid of the aforementioned electromagnet and which is open to stop the supply of electrical power to said solenoid when the value of an operating parameter   motor exceeds a predetermined level.   9. System according to claim 8 characterized in that the aforesaid vibration absorption means comprises a first rod (40) integrally connected to the aforesaid cylinder and connected to the vehicle body and a second rod (42) integrally connected to the aforementioned plunger and connected to the aforementioned vibration generating device. 10. System according to claim 9, characterized in that the aforesaid vibration-generating device comprises   an internal combustion engine (24) mounted on the coach- above mentioned.   11. System according to claim 10, characterized in that the operating parameter of the engine is its speed.   12. System according to claim 7, characterized in that the vibration generating device is an assembly of a rear axle (50), in that the aforesaid signal generator comprises a switch (29A) electrically connected to the solenoid of the electromagnet and which is closed to supply electrical power to said solenoid when the   engine load exceeds a predetermined level.   13. System according to claim 12, characterized in that the aforesaid vibration absorption means comprises a first rod (40) integrally connected to the aforementioned cylinder and connected to the vehicle body and a second rod (42) integrally connected to the plunger.   aforementioned and connected to all of the aforesaid rear axle.   14. System according to claim 13, characterized in that the switch is arranged to open when the degree of operation of a throttle valve exceeds a predetermined level.