Description FRAME BALANCING REDUCTION ASSEMBLY Technical Field The present invention relates to vibration assemblies for use on a vehicle, and more particularly to vibration reducing assemblies that reduce vibration of the frame to provide smooth movement. BACKGROUND OF THE INVENTION Long-range trucks and other automotive vehicles experience a significant amount of vibration during operation as the vehicle travels on rough and uneven roads. One of the most important factors in the movement of a heavy truck is the degree of oscillatory movement that occurs in the frame of the truck as a result of the vibratory forces exerted on the frame, particularly the oscillating movement in the natural frequency of the frame. The oscillating movement of the natural frequency of the frame is known as swinging of the frame. The frame of a heavy truck is usually a pair of metal channels with transverse members between them, and the main components of the truck are fastened to this frame, including the engine, cab, fuel tanks, radiator, fifth wheel, and air conditioning systems. suspension. The oscillation of the frame is excited by the scale of vibrational forces transmitted to the frame as the truck travels over periodic points on the road, such as cracked and slanted concrete slabs. The sway of the frame is also excited by the movement of components mounted to the frame, such as the rotation of the wheel set, particularly if the wheel set is out of revolution or out of balance. In a conventional heavy truck, the front and rear ends of the frame are free ends, and the oscillation of the frame during frame swing is the first mode of frame bending, and said swing is a substantially harmonic oscillation. Consequently, the frame vibrates at a relatively low frequency with two stationary nodal points occurring at the point about a quarter of the length of the frame of each of the front and rear ends. At least, a portion of the truck cab is attached to the frame at a position away from the nodal points that experience vertical movement due to the frame swing, and that vertical movement of the frame is transmitted to the cab. As a result, the driver experiences the oscillatory movement as a movement of pitch forward and backward of the cab during vehicle operation. The magnitude of the forward and backward pitch movement is increased due to the elevated position of the driver in the cabin above the frame. This movement of pitch is annoying and uncomfortable for the driver or a passenger in the truck, particularly on long trips.
There have been numerous efforts to reduce the vibration felt by the driver as a result of frame swinging, including the use of air suspension seats, and modified suspension systems, designed to reduce pitching back and forth. The wheels have also received attention that many ordinary wheels and wheels are marked at their eccentric points in such a way that the eccentricities can be deviated against each other during assembly to reduce the oscillatory vibration transmitted to the frame. In addition, the frames have been made with greater rigidity or with reinforcements attached to the frame to minimize the vibration of the frame. An additional device used to reduce forward and backward pitching caused by the swinging of the frame, is a cab suspension system between the truck cab and the frame to prevent the vibration of the frame and other road alterations from reaching the driver. Other devices to reduce the vibration transmitted to the vehicle frame are used in the assembly between the engine and the frame. A plurality of elastic devices, vibration absorbers, such as rubber pads or the like, are installed between the frame and the engine mounts on the vehicle engine. These devices are designed to absorb the vibration generated from the motor in order to prevent said vibration of the motor from being transmitted to the frame. However, the vibration of the motor is of a frequency higher than the frequency of the frame swing. While rubber pads or other vibration absorbing devices of the motor can absorb or reduce the vibration of the upper frequency motor, these devices do not control the lower frequency vibration of the frame swing. SUMMARY OF THE INVENTION The present invention provides a balancing reduction assembly that reduces the rolling of the frame in a vehicle In a preferred embodiment of the invention, the frame swing reduction assembly is an auxiliary mass damping system, which includes a frame assembly, a motor coupled to the frame assembly, and a spring and damper between the motor and the frame assembly.The frame assembly has a pair of frame rails laterally spaced apart and transverse members extending between the tracks of the frame and the frame assembly. Frame The frame assembly has a relatively low swing frequency.The motor has at least one mounting portion connected to the spring and the shock absorber.The spring and the shock absorber are connected to the frame assembly between the frame assembly and the motor. , and the spring and the shock absorber support a portion of the weight of the motor on the frame, in such a way that the motor e an auxiliary mass to activate the spring and the shock absorber. The spring and the damper are combined with the motor to provide a combination that has a frequency of deflection and is substantially equal to the swing frequency and which deviates from the swing frequency. As a result, the amplitude of the roll frequency is reduced to approximately zero, and the driver does not feel the forward and backward pitch which is otherwise detectable during the roll of the undamped frame. In the preferred embodiment of the invention, the motor has front mounting portions and rear mounting portions. The spring and the damper are located between the front mounting portions and the front transverse member of the vehicle frame. The damper has a predetermined damper constant and the spring member has a predetermined spring intensity, such that the damper and the spring in combination with the auxiliary mass of the motor provide the frequency of deflection which is substantially equal to, and ° out of phase with, the swing frequency. Consequently, the combination of the spring member, shock absorber member, and auxiliary motor mass reduces the sway of the frame. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view, schematic, of a truck having a frame swing reduction assembly according to the preferred embodiment. Figure 2 is an elongated, elevational side view of the swing reduction assembly of the frame of Figure 1, with an engine coupled to the truck frame by an air spring and shock absorbers connected to the front mounts of the engine. Figure 3 is an elongated, raised front view of the swing reduction assembly of the frame of Figure 1, with an engine coupled to the truck frame by an air spring and shock absorbers attached to the front mounts of the engine. Detailed Description of the Invention A long-range truck 10, illustrated in Figure 1, has a frame 12 that supports a car 14 and frame swing reduction assembly 6, in accordance with the present invention, in a front portion 18. of the frame, as discussed above, a preferred embodiment of the frame swing reduction assembly 16, includes a spring 20 and a damper 22 which are connected to a motor 24 of the truck 10 and to the front portion 18 of the frame 12 to provide a combination of the motor, the spring, and the shock absorber that has a frequency of deviation that diverts the frequency of the oscillatory movement that occurs in the balancing of the frame. The effect of the frame swing reduction assembly 16 is to isolate the front part of the motor 24 so that if the frame 12 tries to vibrate, it is resisted by the spring 20, the damper 22, and the motor mass. The frame 12 of the truck 10 is a structure that includes a pair of laterally spaced frame rails 26, which extend substantially along the length of the truck. The transverse members 28 of the frame 12 extend between the rails 26 of the frame and are secured at each end of the rails of the frame. The frame 12 is the central structural component of the truck 10 supporting the other components of the truck, including the car 14, suspension systems, a fifth wheel, the power plant, which includes the engine 24 and the transmission, and many other components . As the truck 10 travels on a road, the frame 12 is subjected to a wide variety of vibratory forces resulting from, for example, the wheels of the truck moving on rough and uneven surfaces. Said vibratory forces are transmitted through the suspension system of the truck to the frame 12. Other vibratory forces exerted on the frame 12 are caused by components of cyclic movement of the truck 10 that are out of balance or out of revolution, such as the movement inside. of the motor 24. These vibratory forces transmitted to the frame 12 cause the frame to flex in a first bending mode thus resulting in the vibratory oscillations of the frame, known as frame swinging. The vibratory oscillation of the frame has a substantially resonant frequency in the natural frequency of the frame. These vibratory oscillations of the frame at the swing frequency are substantially harmonic in such a way that the front portion 18 of the frame 12, as well as the middle portion and the rear portion of the frame, will move vertically up and down during the ba frame lanceo not damped. The portion of the frame 12 at a node nodal point 32 that is located approximately one quarter of the length of the truck frame 12, away from the front potion 18 of the frame, is substantially stationary and has no relative vertical movement, even during the non-cushioned rolling of the frame. However, during the swinging of the frame, the positions along the frame 12 that are far from the forward nodal point 32, tend to experience a vertical movement scale. The frame 12 of the truck has a resonant frame swing frequency in the range of 4 cycles / second (Hertz) at 10 cycles / second (Hertz) and more usually in the scale from 5 Hertz to 8 Hertz. The exact frequency depends on a number of design factors and can be measured for each design as needed. The frame swing reduction assembly 16 of the preferred embodiment includes the combination of the motor 24, which provides a relatively large auxiliary mass, the spring 20, and the damper 22 which generates a frequency of deviation substantially equal to the swing frequency and approximately 180 ° out of phase with the swing frequency. Consequently, the frame swing reduction assembly 16, reduces the amplitude of vertical movement in the frame 12 to substantially zero. As a result, the components connected to the frame 12 of the truck 10, such as the car 14 and the like, do not experience displacement. vertical oscillatory due to the rolling of the frame. Thus, the truck driver 10 experiences a very uniform movement.
The engine 24 of the preferred embodiment is a six-cylinder diesel engine weighing approximately 1814.4 kg, and the engine provides a large auxiliary mass for the frame swing reduction assembly 16, which drives the damper 22 and the spring 20. The motor 24 generates a significant amount of motor vibration because, for example, the mass is imbalanced during the rotation of the motor parts, and due to the multiple ignition within the motor during each cycle. The frequency of motor vibration during operation is on a scale of 16 Hertz at idle speeds, at 105 Hertz at high engine speeds. Consequently, the scale of vibration frequencies of the motor is different and higher than the scale of the swinging frequencies of the frame. The motor 24 has rear mounts 34 of the motor and front mounting portions 36 of the motor that are adapted to be securely attached to the frame 12. The rear mounts 34 of the motor are connected to the frame 12 in a conventional manner at a position corresponding approximately to the first nodal point 32. The rear motor mounts 34 are adapted to carry a portion of the weight of the motor and to withstand substantially all the torque loads and lateral loads generated by the motor 24 during operation. As best seen in Figures 2 and 3, the engine 24 has a plurality of front engine mounting parts 36, including a left shock mount 40, a right shock mount 38, and first and second mounts 42 and 44 , adjacent centrals. The left and right mountings 40 and 38 each have a mounting plate 46 screwed, or otherwise securely fastened to a flange 48 extending outwardly from the respective left and right sides of the block support 50. motor 24. Each of the mounting plates 46 has a plurality of openings 52 in a lower portion 54 of the mounting plate that are adapted to receive the fasteners 55 that rigidly connect the mounting plate to the block support 50. the motor. An upper opening 56 is formed in an upper portion 58 of each mounting plate 46 for connecting the mounting plate to the left and right shock absorbers 60 and 62, comprising a shock absorber 22. An upper portion 64 of each of the left and right shock absorber 60 and 62, is securely attached to the respective mounting plate 46, by a fastener 66 extending through the upper portion of the absorber and through the upper opening 56 in the mounting plate . As illustrated in Figure 3, each of the left and right shock absorbers 60 and 62 extend downwardly from its mounting plate 46 and are secured securely in the lower portion 68 to the transverse member 28 of the frame 12 and a knee support 70 connecting the cross member to the rails 26 of the frame In the preferred embodiment, each of the left and right shock absorbers 60 and 62, of shock, is a short strike of 3.43 cm having a stroke of approximately 2.51 cm, and having connectors 72 of steel ball end, to minimize the elasticity of the crashes, thus facilitating its damping characteristics. The combination of the left and right shock absorbers 62 and 60, provides a constant damping on the scale of 714 kg / m / sec to 1785 kg / m / sec. Shocks of short strokes of 3.45 cm of the preferred modality provide a constant damping in the scale of 892.5 kg / m / sec and 107 kg / m / sec, and more particularly, an optimum damping constant, of 981.75 kg / m / s, for the particular modality illustrated. The steel ball connectors 72 in the lower portion 68 of each of the left and right shock absorbers 62 and 60 are fastened with the fastener 74 to the knee support 70., respective. As best seen in Figure 3, each knee support 70 is an L-shaped support with a first end 78 that is securely fastened to a respective frame rail 26, with a pair of fasteners 80. A second end 82 of the Knee support 70 extends inwardly away from the frame rail 26 and connects to a respective left and right end 84 and 86 of the transverse member 28 of the frame. The second limb 82 of the knee support 70 has a pair of openings 88 in it, which are coaxially aligned with a pair of openings 90 at each of the left and right lateral ends 86 and 84 of the transverse member 28. The fasteners 74 and 92 extend through the openings 88 and 90 and rigidly connect the transverse member 28 to the respective knee supports 70. The openings 88 in the second end 82 of the knee support 70 are vertically deflected below the fasteners 80, securing the knee support to the frame rail 26. Consequently, the transverse member 28 is connected to the frame rail 26 in a lowered position to provide a space 94 between the lower surface 96 of the motor block support 50 and an upper surface 98 of the transverse member. The transverse member 28 is a surface V configuration, with a lower planar portion 100, positioned below the engine block support 50, with a space 94 between the lower surface 96 of the engine block and the upper surface 98 of the member. cross. The spring 20 is located within the space 94, and an upper portion 102 of the spring is securely connected to the engine block support 50, in the first central assembly 42 of the engine. A lower portion 104 of the spring 20 is securely fastened to the middle portion 100 of the transverse member 28, such that the spring extends over the space 94 and supports the forward portion 106 of the motor 24. Consequently, the spring 20 and the left and right shock absorbers, 62 and 60, are placed substantially in parallel, and the front portion 106 of the motor 24, are elastically supported above the transverse member 28 by the spring. In the preferred embodiment, the spring 20 is an air spring that provides vibration absorption between the motor 24 and the middle section 100 of the transverse member 28. The air spring 20 has an air valve for height control (not shown) adding or removing air slowly give the air spring to control the installed height of the air spring, in a well known way for air spring installations. The air spring 20 has a spring intensity in the range of 26775 kg / m to 62475 kg / m. A preferred scale of spring intensity is 40162.5 kg / m at 49087.5 kg / m, the optimum spring intensity being 1912 kg / m to be used in combination with the left and right shock absorbers, 60 and 62, short stroke , treated previously and with a diesel engine of six cylinders, of approximately 1812 kg. Therefore, the shock absorber 22 formed by the two shock absorbers 62 and 60 and the spring 20, in combination with the mass of the motor 24, results in a damping system of the auxiliary mass, the motor being the auxiliary mass for actuating the shock absorbers and spring in order to deflect the frame swing, from the frame 12. In addition, the combination of the motor 24, the spring 20, and the damper 22, provides a set 16 of swing reduction of the frame, which is widely tuned in such a way that the variations of the damping constant and spring speed can be used within the identified scales, while effectively eliminating or reducing the frame swing. This system is, therefore, useful for many different truck designs. Referring again to Figure 3, the frame swing reduction assembly 16, has a trajectory detent 108, located adjacent to the spring 20 in the space 94 between the engine block support 50, and the transverse member 28. The trajectory detent 108 includes a member of blocks 122 and an alignment pin 1 10 extending through the block member. The alignment bolt 1 10 is connected to the motor support 50 in the second central assembly 44. The alignment bolt 110 extends from an elongated upper portion 12 through an opening 1 in the support 50. of engine blocks in the second central assembly 44, through an opening 1 16 in the block member 122, and through an opening 1 18 in the median portion 10 of the transverse member 28. A nut 120 or the like is attached to the end of the alignment bolt 1 10 below the middle portion 100 of the transverse member 28, to prevent the alignment bolt from pulling through the opening 1 18 in the middle portion of the member. cross. The alignment pin 1 10 effectively limits the relative vertical movement of the motor 24 away from the frame 12. The block member 122 is a rigid steel body having a tapered configuration with a height that is less than the height of the body. space 94 between the motor 24 and the transverse member 28 Consequently, the motor 24 can move vertically in relation to the upper surface 98 of the transverse member 28, a distance corresponding to the difference in the heights of the block member 122 and the lower part of the motor support 50. When the block support 50 of the motor moves towards the transverse member 28 to the position corresponding to the upper part of the block member 122, the block member will engage the lower surface 96 of the block support 50 of the motor, and avoids the Additional relative movement of the motor. In the preferred embodiment, the vertical path scale of the motor 24, relative to the transverse member 28, is approximately +0.635 cm. In an alternative embodiment not illustrated, the left and right shock absorbers 62 and 60 provide path limits for the movement of the motor 24, relative to the transverse member 28, so that the path detent 108 can be eliminated, discussed earlier. Consequently, the left and right shock absorbers 62 and 60 connect the front portion 106 of the engine 24 to the transverse member 28, and the combination of the shock absorbers provide a shock absorber between the engine and the frame 12. The weight of the engine 24 , effectively drives the left and right shock absorbers 62 and 60, to facilitate damping by shock absorbers. Although the preferred embodiment described above utilizes two short stroke shock absorbers to provide damping between the front of the engine and the cross member, other dampers or a single shock absorber can be used having a selected damping constant between the engine and the cross member . The dampers can also be attached to the rails 26 of the frame, instead of the transverse member, to provide the desired damping. In an alternative embodiment of the present invention, the frame swing reduction assembly 16 has an air spring 20 positioned between the central assembly 42 of the block support 50 the engine and the transverse member 28 of the frame 12, to form a dynamic vibration absorber system. The air spring 20 provides both a light damping function and a spring function. The air spring 20 is combined with the mass of the motor 24 to provide a combination having a frequency of deflection that is substantially equal to the roll frequency and which deflects the roll frequency. This deviation from the roll frequency effectively reduces the amplitude of the harmonic oscillations of the frame 1 2 that occur in the roll of the frame. The alternative mode uses an air spring 20 only, to provide a simple member that acts as a spring and a very small damper, and the resulting dynamic vibration absorber system is tuned very tightly due to the small amount of damping. Therefore, small variations in the intensity of the spring for the system, if closely tuned, can adversely impact the system, for example, resulting in a deviation frequency that does not completely deviate the frame swing frequency. . Consequently, the intensity of the spring must be selected very carefully with respect to the remaining components of the frame swing reduction assembly, including the mass of the moto'r, the swinging frequency of the frame, the frame, and the like, to provide a Deviation frequency that is equal to, and is offset with, the frame swing frequency. The dynamic vibration absorption system of this alternative embodiment using the air spring 20 alone, results in the development of two additional vibrations that are exerted on the frame 12, including a frequency oscillation in the frame that is greater than the of the frame swing frequency discussed above, and a lower frequency of motor oscillation. As a result, the dynamic vibration absorption system with an undamped spring arrangement of the alternative embodiment is effective to deflect the frame swing frequency, particularly in a vehicle that is not adversely affected by the two additional vibrations. However, the dynamic vibration absorption system is not as widely tuned as the frame swing reduction system of the preferred embodiment with the spring and damper arrangement.
Numerous modifications and variations of the invention of the frame swing reduction system, described herein, will occur to those skilled in the art. Therefore, it should be understood that such modifications and variations may be practiced while remaining within the spirit and scope of the invention as defined by the following claims.