JP2007170476A - Driving shaft damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving shaft damper capable of locking a sound shielding cover 8 to a rim portion 11 of a hub 1 without forming a locking groove therein and therefore requiring an increase in the thickness of the rim portion 11, resulting in the reduced weight of the hub 1 and reduced machining cost to lower a product price. <P>SOLUTION: A mounting cylinder portion 21 of a sensing plate 2 for detecting the rotation of a driving shaft is pressed into the rim portion 11 of the hub 1. Between an inward edge 23 of the mounting cylinder portion 21 and the rim portion 11, a locking groove is formed for locking an outer peripheral edge 81 of the sound shielding cover 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a damper attached to a drive shaft in order to reduce resonance of the drive shaft of a rotating device such as a crankshaft of an engine.

Conventionally, for example, a torsional damper as disclosed in Patent Document 1 below is known as a kind of damper attached to a drive shaft.
JP 2005-282852 A

  In other words, in order to reduce the vibration generated in the crankshaft of an engine such as an automobile, a torsional damper is attached to the end of the shaft. This type of torsional damper generates a large noise due to vibration transmission from the crankshaft. There is a problem of radiation. In Patent Document 1, in order to reduce such noise radiation, a sound insulation cover made of a rubber-like elastic material is attached to the front of the torsional damper.

  However, according to the prior art described in Patent Document 1, since it is necessary to carve a locking groove for locking the sound insulation cover in the rim portion of the hub, it is necessary to increase the thickness of the rim portion. For this reason, the weight of the hub was large. In addition, since the locking groove is formed by cutting, the processing cost is increased, resulting in a problem that the product price is high.

  The present invention has been made in view of the above points, and a technical problem thereof is a drive shaft capable of locking a sound insulating cover without carving a locking groove in the hub. It is to provide a damper for use.

  As means for effectively solving the above technical problem, a drive shaft damper according to the invention of claim 1 includes a hub attached to the drive shaft, a dynamic damper portion and / or a coupling disposed on the outer periphery thereof. In the damper provided with a portion, an annular body is press-fitted into the hub, and an outer peripheral edge of the sound insulation cover can be locked between the annular body and the hub.

  A damper for a drive shaft according to a second aspect of the invention is characterized in that, in the configuration of the first aspect, the annular body is a sleeve formed on a sensing plate for detecting the rotation of the drive shaft. It is.

  According to the drive shaft damper according to the first aspect of the present invention, it is not necessary to carve a locking groove for locking the outer peripheral edge of the sound insulation cover in the hub, and therefore it is necessary to increase the thickness of the hub. As a result, the product price can be reduced by reducing the weight of the hub and reducing the processing cost.

  According to the drive shaft damper of the invention of claim 2, since the outer peripheral edge of the sound insulating cover is locked using the sleeve of the sensing plate, the outer peripheral edge of the sound insulating cover is locked. There is no need to provide an annular body separately.

  Hereinafter, the drive shaft damper according to the present invention is applied to a torque fluctuation absorbing damper that transmits torque from a crankshaft of an automobile engine to an auxiliary machine, absorbs fluctuations in the torque, and reduces torsional vibration of the crankshaft. A preferred embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing this embodiment cut along a plane passing through the axis O, and FIG. 2 is a plane passing through the axis O in a state where a sound insulation cover is attached to the torque fluctuation absorbing damper of FIG. It is sectional drawing cut | disconnected and shown by. In the following description, “front side” means the left side in the figure and the front side of the vehicle, and “back side” means the right side in the figure and the side where the engine (not shown) exists. It is.

  In FIG. 1, reference numeral 1 is a hub attached to an end of a crankshaft (not shown) of an automobile engine. The hub 1 is manufactured by casting a metal material or the like, and has a shaft hole 1a into which an end of a crankshaft is inserted and a positioning hole 1b in the circumferential direction on the inner periphery. In addition, a rim portion 11 protruding in a cylindrical shape toward the front side is formed.

  Reference numeral 2 is a sensing plate made of a metal plate such as a steel plate. The sensing plate 2 has a mounting cylinder portion 21 that is press-fitted into the outer peripheral surface of the rim portion 11 of the hub 1, and a main body flange 22 that is developed in a disc shape from an end portion on the back side. A large number of detected protrusions 22 a are formed on the outer peripheral edge of the main body flange 22 at equal phase intervals. An unillustrated sensor (not shown) is disposed close to the outer peripheral side of the main body flange 22, and the detected protrusion 22 a passes in front of the reading head of the sensor as it rotates, thereby causing a pulse-like shape. A detection signal is output, and crank angle detection for engine control is performed.

  A dynamic damper portion 3 and a coupling portion 4 are provided on the outer peripheral side of the hub 1.

  Among these, the dynamic damper portion 3 includes a sleeve 31 press-fitted to the outer peripheral surface of the mounting cylinder portion 21 of the sensing plate 2, a pulley holding ring 32 disposed on the outer peripheral side, the pulley holding ring 32, It is made of a damper rubber 33 integrally vulcanized with a rubber-like elastic material having excellent heat resistance, cold resistance, internal damping and mechanical strength between the sleeve 31 and the sleeve 31.

  Specifically, the pulley holding ring 32 is manufactured by press molding of a metal plate or the like, and includes an inner peripheral cylindrical portion 321 integrally bonded to the outer periphery of the damper rubber 33 by vulcanization adhesion, and an end on the back side thereof. The cylindrical part 322 which expands from the outer part to the outer peripheral side and the outer peripheral cylindrical part 323 extending further from the outer periphery to the front side of the disk part 322 are formed into a double cylindrical hollow shape, that is, cut by a plane passing through the axis O. The shape (the cross-sectional shape shown in the figure) is substantially U-shaped.

  The damper rubber 33 sets a sleeve 31 and a pulley holding ring 32 concentrically on a mold (not shown), and clamps the outer peripheral surface of the sleeve 31 and the inner peripheral surface of the inner peripheral cylindrical portion 321 of the pulley holding ring 32. By filling the annular cavity defined between the two with an unvulcanized rubber material and heating / pressing it, the outer peripheral surface of the sleeve 31 and the inner peripheral surface of the inner peripheral cylindrical portion 321 are simultaneously formed with vulcanization. Vulcanized and bonded. Since the sleeve 31 is slightly expanded in diameter by being press-fitted into the outer peripheral surface of the mounting cylinder portion 21 of the sensing plate 2, the damper rubber 33 is free from tensile stress caused by volume shrinkage during molding and is also radially A suitable pre-compression is given.

  On the other hand, the coupling portion 4 includes a coupling flange member 41 fixed to the pulley holding ring 32, a pulley 42 supported so as to be relatively rotatable on the outer peripheral cylindrical portion 323 of the pulley holding ring 32, and the pulley 42 and the coupling. It consists of a coupling rubber 43 integrally vulcanized and molded with a rubber-like elastic material excellent in heat resistance, cold resistance, internal damping and mechanical strength between the flange member 41.

  The coupling flange member 41 is manufactured by a metal plate punching press or the like, and includes a mounting cylinder portion 411 press-fitted to the outer peripheral surface of the inner peripheral cylindrical portion 321 of the pulley holding ring 32, and a rear side thereof. It consists of an outward flange 412 developed from the end along the disk portion 322 of the pulley holding ring 32.

  The pulley 42 is manufactured by press forming and rolling of a metal plate, and includes a pulley main body 421 disposed on the outer peripheral side of the outer peripheral cylindrical portion 323 of the pulley holding ring 32 and an end portion on the front side thereof. It consists of an inward flange 422 extending inward from the front side of the outer peripheral cylindrical portion 323. A poly V groove 421a is formed on the outer peripheral surface of the pulley main body 421, and an endless belt (not shown) is wound around the pulley main body 421.

  The coupling rubber 43 is integrally vulcanized and bonded to the outward flange 412 of the coupling flange member 41 and the inward flange 422 of the pulley 42. That is, the coupling rubber 43 is configured such that the coupling flange member 41 and the pulley 42 are concentrically set in a mold (not shown), and the outward flange 412 of the coupling flange member 41 and the inward flange of the pulley 42 are clamped. A cylindrical cavity formed between the outer flange 412 and the outer flange 422 is vulcanized and bonded to the outward flange 412 and the inward flange 422 simultaneously with vulcanization molding by filling an unvulcanized rubber material into a cylindrical cavity defined between It is a thing.

  The coupling rubber 43 transmits the driving torque input from the crankshaft to the hub 1 to the pulley 42 while being smoothed by a circumferential shear deformation action. Since the torque fluctuation of the crankshaft becomes significant in the low rotation region below idling, this coupling rubber 43 reduces the spring constant as much as possible and increases the allowable deformation amount in the torsion direction as much as possible. In order to give a torque transmission force, the axial and radial thicknesses are sufficiently large.

  A radial bearing 5 is interposed between the outer peripheral cylindrical portion 323 of the pulley holding ring 32 and the pulley main body 421 of the pulley 42 on the outer peripheral side thereof. The radial bearing 5 is formed in a cylindrical shape with a synthetic resin material having a low friction coefficient and excellent in wear resistance such as PTFE, and supports the inner peripheral surface of the pulley body 421 so as to be freely slidable. Yes.

  A thrust supporter 6 is attached to the pulley holding ring 32 so as to be positioned on the front side of the coupling flange member 41. The thrust supporter 6 includes an inner peripheral press-fit portion 61 press-fitted to the outer peripheral surface of the inner peripheral cylindrical portion 321 of the pulley holding ring 32, and a support flange in which the front side of the inward flange 422 of the pulley 42 is expanded to the outer peripheral side. 62.

  The thrust bearing 7 is interposed between the inward flange 422 of the pulley 42 and the support flange 62 of the thrust supporter 6 having a conical shape corresponding thereto so as to be able to rotate and slide. The thrust bearing 7 is formed into a conical ring shape with a synthetic resin material having a low friction coefficient and excellent wear resistance such as PTFE.

  In the assembly of the torque fluctuation absorbing damper, the coupling flange member 41 is press-fitted into the outer peripheral surface of the inner circumferential cylindrical portion 321 of the pulley holding ring 32, so that the coupling flange member 41, the pulley 42, and the coupling rubber 43 are After the coupling portion 4, which is an integrally molded product, is assembled in the pulley holding ring 32, this thrust supporter 6 is pressed into the outer peripheral surface of the inner peripheral cylindrical portion 321 from the front side to a predetermined position in the axial direction. The support flange 62 of the supporter 6 appropriately presses the inward flange 422 of the pulley 42 to the back side through the thrust bearing 7. For this reason, the coupling rubber 43 is given appropriate pre-compression in the axial direction.

  On the support flange 62 of the thrust supporter 6, a plurality of engaging protrusions 63 projecting toward the back side are formed at equal phase intervals. On the other hand, the inward flange 422 of the pulley 42 is provided with a plurality of engagement holes 422a extending in an arc shape centering on the axis O at phase intervals corresponding to the engagement protrusions 63, respectively. The protrusion 63 is loosely fitted to both sides in the circumferential direction with an appropriate clearance. That is, the engagement protrusion 63 and the engagement hole 422a constitute a stopper that restricts the relative displacement in the circumferential direction of the pulley holding ring 32 and the pulley 42 within a predetermined range by mutual interference. Further, the back side of the engagement hole 422 a is closed by a blind hole 431 formed on the outer periphery of the front end portion of the coupling rubber 43.

  Thrust strips 331 and 332 made of a rubber-like elastic material and continuously in the circumferential direction are integrally vulcanized and bonded to the outer peripheral portion and the inner peripheral portion of the back surface of the disk portion 322 of the pulley holding ring 32, respectively. The tip is slidably in close contact with the inner surface of the main body flange 22 of the sensing plate 2. Further, a radial seal lip 333 made of a rubber-like elastic material and continuous in the circumferential direction is integrally vulcanized and bonded to the outer peripheral side of the thrust strip 331, and the tip thereof is outside the radial bearing 5 (back side). ) Is slidably in close contact with the inner peripheral surface of the pulley body 421 of the pulley 42.

  The thrust strips 331 and 332 and the radial seal lip 333 are made of a rubber-like elastic material that is the same material as the damper rubber 33, and are formed at the same time when the damper rubber 33 described above is integrally formed.

  A thrust seal lip 432 made of a rubber-like elastic material continuous with the coupling rubber 43 is integrally vulcanized and bonded to the outer peripheral side of the opening position of the engagement hole 422a on the outer surface of the inward flange 422 of the pulley 42. The tip of the thrust supporter 6 is in close contact with the outer peripheral portion of the inner surface of the support flange 62 so as to be slidable. The thrust seal lip 432 can be simultaneously formed when the coupling rubber 43 is integrally formed with the outward flange 412 of the coupling flange member 41 and the inward flange 422 of the pulley 42 described above.

  The damper rubber 33 forms a spring portion of the dynamic damper portion 3, and includes a pulley holding ring 32, a coupling flange member 41 provided integrally with the inner peripheral cylindrical portion 321 of the pulley holding ring 32, the thrust supporter 6, The thrust strips 331 and 332, the radial seal lip 333, and the like form mass portions of the dynamic damper portion 3. The torsional direction natural frequency of the dynamic damper portion 3 is a predetermined frequency region in which the torsion angle of the crankshaft is maximized by the spring constant of the damper rubber 33 and the inertial mass of the mass portion. It is tuned to match the torsional direction natural frequency.

  The front end portion of the mounting cylinder portion 21 in the sensing plate 2 extends to the front side of the rim portion 11 of the hub 1 and is formed with an inward edge portion 23 bent toward the inner peripheral side. And between this inward edge part 23 and the front edge part of the said rim | limb part 11, it is the locking groove | channel A which continued in the circumferential direction.

  The sound insulation cover 8 shown in FIG. 2 is formed of a rubber-like elastic material, and has an outer diameter substantially equal to the outer diameter of the hub 1 and fixes the hub 1 to a shaft end of a crankshaft (not shown). The head 10a and the washer 10b of the center bolt 10 are formed in a dish shape that can cover the front side. And the outer periphery 81 of this sound insulation cover 8 is formed in the convex shape which can be fitted to the locking groove A mentioned above, and is continued in the circumferential direction. A stepped portion 82 is formed that is continuous with the inward edge 23 of the portion 21 in the circumferential direction.

  A damper (torque fluctuation absorbing damper) having the above-described configuration is attached to a shaft end of a crankshaft (not shown) by a center bolt 10 indicated by a two-dot chain line in FIG. This is transmitted to a rotating shaft of an auxiliary machine such as an alternator via a belt (not shown) wound around the pulley body 421.

  Here, torque fluctuations that are conspicuously generated in the crankshaft in the low rotation range below idling are transmitted from the hub 1 to the pulley holding ring 32 via the damper rubber 33. The coupling flange member integral with the pulley holding ring 32 41 and the inward flange 422 of the pulley 42 have a significantly lower circumferential shear spring constant than the damper rubber 33, so that the circumference of the coupling rubber 43 varies depending on the input torque fluctuation. It is repeatedly sheared in the direction to convert this torque fluctuation into heat energy. For this reason, the torque transmitted to the belt wound around the pulley body 421 of the pulley 42 is smoothed.

  The dynamic damper portion 3 resonates in the circumferential direction in the frequency range where the torsion angle is maximized by the resonance of the crankshaft, and the direction of the torque resulting from the resonance is opposite to that of the input vibration. For this reason, the peak of the torsional angle due to the resonance of the crankshaft can be effectively reduced by such a dynamic vibration absorbing action.

  Since the pulley holding ring 32, the coupling flange member 41 and the thrust supporter 6 integrated with the pulley retaining ring 32 act as an inertial mass of the dynamic damper portion 3, a sufficient damping torque at the time of the above-described dynamic vibration absorption can be obtained. .

  Further, when the relative displacement amount in the circumferential direction between the pulley holding ring 32 and the pulley 42 reaches a predetermined size due to the resonance of the coupling portion 4 in the low rotation region or an excessive torque input. The engagement protrusions 63 formed on the thrust supporter 6 integral with the pulley holding ring 32 and the engagement holes 422a formed on the inward flange 422 of the pulley 42 interfere with each other in the circumferential direction. The amount of relative displacement in the circumferential direction between the pulley holding ring 32 and the pulley 42 limited by this interference is set appropriately in consideration of the allowable amount of circumferential strain in the coupling rubber 43. Further, excessive deformation of the coupling rubber 43 and damage resulting therefrom can be effectively prevented.

  The outer side (rear side) of the location where the radial bearing 5 is disposed is sealed by a radial seal lip 333 provided on the pulley holding ring 32 and slidably in close contact with the inner peripheral surface of the pulley body 421. Early wear and damage to the radial bearing 5 due to intervention can be prevented. Similarly, the outer side (outer peripheral side) of the place where the thrust bearing 7 is disposed is sealed by a thrust seal lip 432 provided on the inward flange 422 of the pulley 42 and slidably in close contact with the thrust supporter 6. Premature wear and damage of the thrust bearing 7 due to dust intervention can be prevented.

  Here, the vibration generated in the crankshaft is transmitted to the hub 1 attached to the shaft end. As shown in FIG. 2, the sound insulation cover formed of a rubber-like elastic material on the front side of the hub 1 is used. By mounting 8, the noise radiation from the hub 11 can be effectively reduced by the shielding action and the internal damping action of the rubber-like elastic material.

  And according to the form of illustration, the sound insulation cover 8 has the outer peripheral edge 81, the inward edge part 23 formed in the front edge part of the attachment cylinder part 21 in the sensing plate 2, and the front surface of the rim | limb part 11 of the hub 1. It can be mounted by engaging and locking in a locking groove A between the end portions. For this reason, it is not necessary to engrave a locking groove for locking the outer peripheral edge 81 of the sound insulating cover 8 into the rim portion 11 of the hub 1 by machining or the like. Therefore, the thickness of the rim portion 11 is increased. As a result, the product price can be reduced by reducing the hub weight and processing costs.

  Further, since the outer peripheral edge 81 of the sound insulation cover 8 is locked by the inward edge portion 23 formed on the mounting cylinder portion 21 of the sensing plate 2, an annular member for locking the sound insulation cover 8 is separately provided. There is no need to provide it.

  In this embodiment, the inward edge 23 for locking the outer peripheral edge 81 of the sound insulating cover 8 is formed on the mounting cylinder portion 21 of the sensing plate 2. However, for example, in the case of a damper not provided with the sensing plate 2. Alternatively, the front end portion of the sleeve 31 of the dynamic damper portion 3 may be extended to the front side of the rim portion 11 of the hub 1 to form a locking means with a similar inward edge portion or the like. The present invention can also be applied to a torsional damper as described in Patent Document 1 described above.

1 is a cross-sectional view showing a preferred embodiment of a drive shaft damper according to the present invention by cutting along a plane passing through an axis O. FIG. FIG. 2 is a cross-sectional view showing a state where a sound insulation cover is attached to the torque fluctuation absorbing damper of FIG. 1 by cutting along a plane passing through an axis O;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub 11 Rim part 2 Sensing plate 21 Mounting cylinder part 22 Body flange 23 Inward edge part 3 Dynamic damper part 31 Sleeve 32 Pulley holding ring 33 Damper rubber 331,332 Thrust strip 333 Radial seal lip 4 Coupling part 41 Coupling flange member 42 Pulley 421 Pulley body 422 Inward flange 422a Engagement hole 43 Coupling rubber 431 Blind hole 432 Thrust seal lip 5 Radial bearing 6 Thrust supporter 61 Inner peripheral press-fit portion 62 Support flange 63 Engagement protrusion 7 Thrust bearing 8 Sound insulation cover 81 Outer peripheral edge 82 Step A Locking groove

Claims (2)

  In a damper including a hub (1) attached to a drive shaft and a dynamic damper portion (3) and / or a coupling portion (4) arranged on the outer periphery thereof, an annular body is press-fitted into the hub (1). A drive shaft damper characterized in that the outer peripheral edge (81) of the sound insulation cover (8) can be locked between the annular body and the hub (1).   2. The drive shaft damper according to claim 1, wherein the annular body is an attachment tube portion (21) formed on a sensing plate (2) for detecting rotation of the drive shaft. 3.

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