JP2013228094A - Propeller shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the conditions of resonance vibration and noise associated with bending vibration at low cost without using a special material by increasing the first-order bending resonance frequency and decreasing transfer function gain (vibration response), in a propeller shaft made of FRP which is used in an automobile or the like.SOLUTION: A propeller shaft includes an FRP cylinder body having: a body cylinder part 11 which is a spiral winding layer including a layer of a reinforced fiber and extending in a cylinder axis direction; and a circumferential direction winding layer 15 of the reinforced fiber on the inner peripheral surface of a cylinder axis direction end of the body cylinder part. In a part in the cylinder body excluding 200 mm from each end, the FRP cylinder body has a configuration whose thickness is the same as that of the spiral winding layer of a 200 mm length on both ends and which expands in the radial direction, and a vibration damping member 13 is arranged on the inner surface of the FRP cylinder body or within the FRP cylinder body.

Description

  The present invention relates to a propeller shaft made of fiber reinforced plastic (hereinafter referred to as FRP) used as a driving force transmission shaft of an automobile or the like.

  In the field of the automobile industry, attempts have been made to substitute various parts with FRP materials in order to reduce vehicle weight and reduce fuel consumption. Among the various parts, in the case of an FRP propeller shaft (also called a propulsion shaft), torque transmission for transmitting engine torque to the wheels by connecting to the drive shaft and driven shaft at both ends of the FRP cylinder. It has a structure in which joints are joined.

  Propeller shafts must be prevented from large vibrations caused by resonance and unpleasant noise phenomena with respect to each vibration mode excited by the rotation of the vibration source of the engine or the propeller shaft itself during torque transmission. There is. As the vibration mode of the propeller shaft, bending vibration and membrane vibration can be considered. The bending primary resonance frequency is determined by the cross-sectional secondary moment, longitudinal elastic modulus, specific gravity, and length of the cylindrical body. Therefore, in a steel propeller shaft, the bending primary resonance frequency is divided by dividing the length. However, in the propeller shaft using the FRP cylinder, the primary resonance frequency of the bending is used by effectively increasing the elastic modulus in the axial direction of the FRP cylinder. It is possible to avoid entering the vibration range in the region. In addition, there is a technique in which a vibration damping structure is provided in the FRP cylinder so as to reduce external vibration response and to impart a vibration damping function to the propeller shaft itself.

  Therefore, Patent Document 1 proposes a technique of using a high-modulus grade carbon fiber in order to effectively increase the elastic modulus in the axial direction of the FRP cylinder and improve the bending primary resonance frequency.

  However, the high elastic modulus grade carbon fiber is several times as expensive as the standard elastic modulus grade carbon fiber, and the price of the FRP cylinder itself increases greatly.

  In Patent Document 2, a core that forms a bulging portion of the space inside the FRP cylinder is attached to a mandrel of a metal cylinder used in the filament winding method in order to increase the secondary moment of the section of the FRP cylinder, and the reinforcing fiber is attached by the filament winding method. There has been provided a technique for obtaining a shape that has a necessary and optimum thickness by removing the core after being wound, and in which the FRP cylindrical space expands in the radial direction.

  However, this method requires a step of melting and removing the core with water from the inside of the FRP cylinder, and there is a problem of complexity and an increase in manufacturing cost due to the additional steps.

  Further, it is well known that a cardboard is inserted into the FRP cylinder as a member for reducing the vibration response. However, in Patent Document 3, a cardboard is formed by winding a cardboard a plurality of times to form a paper tube. It is disclosed that since the restoring force is larger than that of the paper tube, the adhesion force between the paper tube and the inner surface of the FRP cylinder is increased, and a higher damping function can be obtained.

  However, this method requires a hard paper that can be expected to have a great restoring force, so that it takes a long time to perform a plurality of winding operations, and the winding operation and the insertion operation into the FRP cylinder are added, resulting in an increase in manufacturing cost. There is.

JP 2008-82525 A JP 2000-108210 A JP 2006-220187 A

  The present invention has been made in view of the above problems, and in a FRP propeller shaft used in an automobile or the like, the bending resonance resonance frequency is improved and the transfer function gain (vibration response) is lowered, and resonance caused by bending vibration is achieved. The objective is to improve vibration and noise at low cost without using special materials.

In order to solve this problem, the present invention has the following configuration. That is,
(1) An FRP cylinder having a main body cylinder portion of a spirally wound layer including a reinforcing fiber layer and extending in the cylinder axis direction, and a circumferential direction winding layer of reinforcing fibers on the inner peripheral surface of the cylinder axis direction end portion of the main body cylinder portion The FRP cylinder has a diameter-expanding portion that swells in the radial direction with the same thickness as the spiral wound layer of both ends 200 mm in the diameter expansion range excluding 200 mm from both ends of the cylinder, and the inner surface of the FRP cylinder Alternatively, the propeller shaft is characterized in that a damping member is disposed inside the FRP cylinder.
(2) The propeller shaft according to (1), wherein the diameter-expanded portion has a thickness of 1 to 5 mm.
(3) The propeller shaft according to (1) or (2), wherein the vibration damping member is wound one or more times by a paper material having a thickness of 0.5 to 1 mm.
(4) The propeller shaft according to any one of (1) to (3), wherein the reinforcing fiber wound in the circumferential direction is wound within a range of ± 80 to 90 degrees with respect to the cylinder axis direction.
(5) The propeller shaft according to any one of (1) to (4), wherein a torque transmission joint is joined to the both ends.

  According to the present invention, the FRP cylinder space is expanded in the radial direction to increase the moment of inertia of the cross section to improve the bending rigidity, and the damping member is applied to the inner surface of the radially expanded area or inside the FRP cylinder by the filament winding method. Since the bending primary resonance frequency can be increased, the transfer function gain (vibration response) can be reduced at the same time, and the resonance vibration and noise associated with the bending vibration can be reduced without using a special material. It can be improved at low cost.

1 is an axial cross-sectional view showing a propeller shaft according to an embodiment of the present invention, in which a portion excluding an end portion of an FRP cylindrical body swells in the radial direction with the same thickness as the end portion, and a damping member is integrally formed on the inner surface It is. A shaft showing a propeller shaft in which a portion excluding an end of an FRP cylinder is radially expanded with the same thickness as the end and a damping member is integrally formed inside the FRP cylinder, which is an embodiment of the present invention FIG. It is an axial sectional view showing a conventional FRP propeller shaft. It is a perspective view which shows the state which wound the damping member (paper) on the mandrel before filament winding. It is a perspective view which shows the damping member (paper) used by one Embodiment of this invention. It is the schematic which shows a mode that the bending mode resonance frequency of a propeller shaft is measured.

  The present invention will be described in more detail with reference to the drawings. 1 and 2 are axial sectional views of a propeller shaft according to the present invention, and FIG. 3 is an axial sectional view of a conventional FRP propeller shaft.

  1 to 3, main body cylinder portions 11, 21, 31 include a reinforcing fiber layer and extend in the cylinder axis direction to form an FRP cylinder, and torque transmission joints 16, 26 are provided at both ends thereof. , 33 are joined. The reinforcing fiber layer constituting the main body cylinder portion is preferably a spiral wound layer of reinforcing fibers in order to make the torsional strength, the bending primary resonance frequency, etc. suitable for the propeller shaft. The winding angle of the spiral winding is usually within a range of ± 10 to ± 45 degrees with respect to the cylinder axis direction. Further, the FRP cylinder may be configured to include circumferential winding layers 15, 25, 32 of reinforcing fibers on the inner peripheral surface of the end in the cylinder axis direction of the main body cylinders 11, 21, 31. When a torque transmission shaft is press-fitted and joined to the circumferentially wound layer of the reinforcing fiber, the corresponding portion of the cylindrical body is reinforced in the circumferential direction, so that deformation and damage to the spirally wound layer can be prevented, and suitable torque transmission is obtained be able to. In the present invention, the circumferential direction usually means a direction within a range of ± 80 to 90 degrees with respect to the cylinder axis direction.

  Here, in FIGS. 1 and 2, the diameter-enlarged portion 14 having a shape that swells in the radial direction with the same thickness as the spirally wound layer of the both-end portions 200 mm in the diameter-enlarged ranges 12 and 22 corresponding to the portions excluding the both-end portions 200 mm in the cylindrical body. , 24 and the damping members 13 and 23 are disposed on the inner surface of the FRP cylinder or inside the FRP cylinder. Here, the reason for excluding both end portions of 200 mm is to secure a reinforcing length necessary for press-fitting of the torque transmission joints 16, 26, and 33.

  The bending primary resonance frequency in the FRP cylinder is affected by the moment of inertia of the cross section (due to the cross section) and the length, and FEM calculation with a computer can be used for the calculation. That is, how much the radial bulge is set with respect to the customer's bending primary resonance frequency specification or how long the radial bulge is set with respect to the axial direction is accurately calculated by using FEM calculation. be able to. The dimensions and the number of turns of the damping members 13 and 23 to be used are also determined by the bulge and length calculated by the FEM calculation.

  Since the enlarged diameter portions 14 and 24 are arranged over the enlarged diameter ranges 12 and 22 in the FRP cylinder, the bending primary resonance frequency can be increased without increasing the amount of reinforcing fiber input compared to the conventional FRP propeller shaft in FIG. Can be improved. Furthermore, since the damping members 13 and 23 are disposed on the inner surface of the FRP cylinder or inside the FRP cylinder, the transfer function gain (vibration response), in particular, the transfer function at the bending primary resonance frequency peak is lowered. Can do.

  The bulges of the enlarged diameter portions 14 and 24 are preferably in the range of 1 to 5 mm. If the bulge is smaller than 1 mm, the effect of the secondary moment of the cross section is small, and the contribution to the bending primary resonance frequency is low. On the other hand, when it exceeds 5 mm, the outer diameter becomes large, and when the propeller shaft is mounted on the vehicle, there is a possibility of interference with peripheral parts.

  Moreover, it is preferable that the sheet | seat thickness of the damping members 13 and 23 exists in the range of 0.5-1 mm. If the sheet thickness is smaller than 0.5 mm, the number of windings is considerably increased in order to secure a necessary radial expansion allowance, which is a complicated operation. On the other hand, if it is larger than 1 mm, the winding work requires a force and bending may occur.

The material of the damping members 13 and 23 is preferably paper, film, or nonwoven fabric (felt), and the basis weight is preferably about 0.5 to 1.5 g / cm ³ . However, among paper, so-called corrugated cardboard is not a preferable mode because the winding work becomes difficult. Further, the damping member 13 is wound around the mandrel 42 one or more times, preferably two or more and five or less. If it is wound more than five times, the overall weight becomes heavy, which may affect the bending primary resonance frequency. The damping member 23 is wound one or more layers between the layers inside the FRP cylinder, and is preferably double or more and five or less as described above.

  In the present invention, carbon fibers, glass fibers, aramid fibers, boron fibers, ceramic fibers and the like are used as the reinforcing fibers, and among these, the use of carbon fibers is preferable in view of the critical rotational speed. When carbon fibers are used as the reinforcing fibers, the reinforcing fibers other than the carbon fibers may be 40% by mass or less based on the total mass of the reinforcing fibers in consideration of the torsional strength and the dangerous rotational speed necessary for the propeller shaft. preferable.

  In addition, the resin impregnated into the reinforcing fiber to form FRP, so-called matrix resin includes epoxy resin, unsaturated polyester resin, phenol resin, vinyl ester resin and other thermosetting resins, polyvinyl acetate resin, polycarbonate resin, polyacetal. Resin, polyphenylene oxide resin, polyphenylene sulfide resin, polyarylate resin, polyester resin, polyamide resin, polyamideimide resin, polyimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyaramid resin, poly Thermoplastic resins such as benzimidazole resin, polyethylene resin, polypropylene resin, and cellulose acetate resin are preferably used. Among these, good workability and after molding Preferably consideration and the thermosetting resin that excellent mechanical properties, among others, epoxy resin is particularly preferably used.

  Moreover, as the damping member, cardboard or a thermoplastic resin sheet is preferable. As the thermoplastic resin sheet, polyvinyl acetate resin, polycarbonate resin, polyacetal resin, polyphenylene oxide resin, polyphenylene sulfide resin, polyarylate resin, polyester resin, polyamide resin, polyamideimide resin, polyimide resin, polyetherimide resin, polysulfone resin, Thermoplastic resins such as polyethersulfone resin, polyetheretherketone resin, polyaramid resin, polybenzimidazole resin, polyethylene resin, polypropylene resin, cellulose acetate resin, and polyethylene terephthalate resin are preferably used. In view of the above, polyethylene terephthalate resin is particularly preferable.

  Next, a method suitable for producing the propeller shaft of the present invention will be described.

  First, the FRP cylindrical body is wound around the mandrel 42 by applying a predetermined tension to the reinforcing fibers impregnated with the matrix resin by a filament winding (hereinafter referred to as FW) method or a tape winding (hereinafter referred to as TW) method. Shape.

  In the present invention, first, the damping member 51 is placed on the mandrel 42 by being wound a plurality of times in order to secure the necessary radial expansion allowance (41). Thereafter, circumferential winding is performed at a position to be the cylindrical axial end portion of the main body cylindrical portion, and the circumferential direction winding is also formed between both end portions to firmly fix the vibration damping member 41 on the mandrel 42. The main body cylindrical portion can be formed continuously and integrally by spiral winding at a winding angle calculated so as to obtain a desired torsional strength and bending primary resonance frequency. When the damping member 51 is arranged inside the FRP cylinder, the damping member 51 is not arranged directly on the mandrel 42, but (a) directly above the circumferential winding layer (immediately before spiral winding), (b) spiral After the winding layer is formed to some extent, it may be interrupted once, and after the vibration damping member 51 is wound a plurality of times, the formation of the spiral winding layer may be resumed (23).

  In the case where a thermosetting resin is used as the matrix resin, a molded body is obtained by putting it into a curing furnace after curing and curing it under predetermined curing conditions. Thereafter, the mandrel is pulled out from the molded body using a decentering machine or the like and cut into a predetermined length using a cutting machine or the like to obtain an FRP cylinder.

  Next, the propeller shaft of the present invention will be described more specifically using examples. In this example, the bending primary resonance frequency and the peak transfer function gain (sound pressure level) evaluation were performed as follows.

[Bending primary resonance frequency and peak transfer function gain (sound pressure level)]
The bending primary resonance frequency and the peak transfer function gain are measured by an impulse excitation test. FIG. 6 is a schematic view showing a state in which a primary bending resonance frequency of the propeller shaft and a transfer function gain (sound pressure level) at the peak thereof are measured. An acceleration sensor 61 is attached to the center of the FRP cylinder 60 to be measured. In this state, the impulse hammer 63 incorporating the input sensor 62 is vibrated, and the outputs of the input sensor 62 and the acceleration sensor 61 are input to the input channel module 64 (for example, AD-3651 manufactured by A & D Corporation). The bend primary resonance frequency and the transfer function at the peak are obtained by obtaining and displaying the transfer function with the dedicated software for FFT (for example, WCAMSA manufactured by A & D Co., Ltd.). Gain (sound pressure level) can be obtained.

(Example)
An FRP cylinder was formed by the FW method. That is, a mandrel having an outer diameter of 80 mm and a length of 1,300 mm was prepared, and a cardboard having a thickness of 1 mm and a length of 700 mm was arranged in a triple roll at a position 300 mm from the end of the mandrel and fixed with heat-resistant tape. Thereafter, three carbon fiber bundles (average single yarn diameter: 7 μm, number of single yarns: 24,000, tensile strength 4900 MPa, tensile elastic modulus: 230 GPa) are drawn, and this is bisphenol A containing a curing agent and a curing accelerator. After impregnating the mold epoxy resin as a matrix resin, first, a portion of 100 mm at one end is wound around eight layers at an angle of ± 82 ° with respect to the axial direction to form a partial layer having a thickness of 2.5 mm. A partial layer is formed in the same manner by winding while winding at ± 82 ° with respect to the axial direction. Subsequently, a main layer having a thickness of 2.5 mm is wound by winding five layers at an angle of ± 12 ° with respect to the axial direction over the entire length of the mandrel. Was then wrapped around the entire length of the mandrel at -83 ° relative to the axial direction.

  Next, the epoxy resin is cured by heating at 180 ° C. for 6 hours while rotating the mandrel. After pulling out the mandrel, each end 50 mm is cut and removed, and the inner diameter is 80 mm and the outer diameters at both ends are An FRP cylinder having a length of 1,200 mm, in which 90 mm, an outer diameter of a portion excluding 250 mm from both ends, 91 mm, and a 3 mm thick cardboard on the inner surface of the portion excluding 250 mm from both ends, was obtained.

  Thereafter, a torque transmission joint 16 was press-fitted and joined to each end of the FRP cylinder to obtain an FRP propeller shaft as shown in FIG.

  When the bending primary resonance frequency of the obtained propeller shaft was measured, it was improved by about 10 Hz (about 5% improvement) to 230 Hz, compared to a comparative example described later. Further, the transfer function gain (sound pressure level) at the bending primary resonance frequency peak value was 20 dB, which was about 15 dB lower than the comparative example (about 40% lower).

  When this propeller shaft was installed in a sports car with a high-speed rotation specification, the number of dangerous rotations could be increased and vibration in the high-speed rotation area could be reduced.

(Comparative example)
An FRP cylinder having an outer diameter of 85 mm, an inner diameter of 80 mm, and a length of 1,200 mm was obtained in the same manner as in the example except that the cardboard was wound on a mandrel to swell the FRP cylinder space in the radial direction. A torque transmission joint 33 was press-fitted and joined to each end of the obtained FRP cylinder to obtain an FRP propeller shaft as shown in FIG.

  With respect to the obtained propeller shaft, the bending primary resonance frequency was measured and found to be 220 Hz. The transfer function gain (sound pressure level) at the bending primary resonance frequency peak value was 35 dB.

  The propeller shaft according to the present invention can be applied to any propeller shaft, and is particularly suitable when applied to a vehicle propeller shaft.

11, 21, 31: Main body cylinder portions 12, 22: Diameter expansion ranges 14, 24: Diameter expansion portions 15, 25, 32: Circumferential winding layers 16, 26, 33: Torque transmission joints 13, 23, 41, 51: Damping member 42: Mandrel 60: FRP cylinder 61: Acceleration sensor 62: Input sensor 63: Impulse hammer 64: Input channel module 65: Host computer

Claims (5)

A FRP cylinder including a main body cylinder portion of a spirally wound layer including a reinforcing fiber layer and extending in the cylinder axis direction and a circumferential winding layer of reinforcing fibers on an inner peripheral surface of a cylinder axis direction end portion of the main body cylinder portion. In addition, the FRP cylinder has an enlarged diameter portion that swells in the radial direction with the same thickness as the spirally wound layer of both ends 200 mm in the diameter expansion range excluding 200 mm from both ends of the cylinder, and the inner surface of the FRP cylinder or the FRP cylinder A propeller shaft characterized in that a damping member is arranged inside the body. The propeller shaft according to claim 1, wherein a thickness of the enlarged diameter portion is 1 to 5 mm. The propeller shaft according to claim 1 or 2, wherein the vibration damping member is wound one or more times with a paper material having a thickness of 0.5 to 1 mm. The propeller shaft according to any one of claims 1 to 3, wherein the reinforcing fiber wound in the circumferential direction is wound within a range of ± 80 to 90 degrees with respect to the cylinder axis direction. The propeller shaft according to any one of claims 1 to 4, wherein a torque transmission joint is joined to the both ends.

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