KR20180124238A - Balance Shaft Module - Google Patents

Abstract

The present invention relates to a balance shaft module, which comprises: a shaft; a shaft base provided on one side of the shaft; a gear detachably mounted on one side of the shaft base; a weight provided eccentrically on the other side of the shaft; a first buffer member mounted between the gear and the shaft base for buffering an impact due to rotation fluctuation of the gear; and a second buffer member installed on the gear to press the gear and the shaft base. Accordingly, the balance shaft module reduces rattle noise by reducing the rotational fluctuations caused by the engine explosion force, in addition to the basic performance in which the weight counteracts the up-down motion of an engine cylinder. Also, the gear and the shaft are installed to be removable and easy to manufacture. A material of the gear is steel for carburizing heat treatment which is good in workability and abrasion resistance, and the shaft and the weight are convenient for machining and handling by using a conventional forging material. In addition, precision machining of the gear is easy, and improvement of durability can be expected by applying a hardening method using the carburizing heat treatment during heat treatment. On the other hand, a cone spring and a snap ring are provided in the gear, and the gear and the shaft are pressed against each other, thereby effectively reducing the resonance occurring at the start or stop of the engine.

Description

Balance Shaft Module {Balance Shaft Module}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance shaft module for an automotive engine, and more particularly to a balance shaft module for an automobile engine, in which gears are detachably mounted on a balance shaft to facilitate manufacture and to prevent vibration and noise by providing a buffer member.

In general, the balance shaft module (BSM: Blance Shaft Module) cancels the vibration caused by the up and down movement of the engine piston. The balance shaft module is applied to engines that generate unbalanced moments or unbalanced masses, such as 4,6-cylinder engines, and are installed on the lower side of the crankshaft or on both sides.

The balance shaft module used in the three-cylinder engine is directly engaged with the crankshaft gear and the balance shaft gear assembled at the crankshaft end in the same number of teeth and rotates in the opposite direction of the engine rotation direction, thereby canceling the upward and downward movement of the first and third cylinders And serves to reduce the engine vibration.

The balance shaft module used in the four-cylinder engine is composed of two shafts parallel to each other, and one shaft may be provided with a drive sprocket. The drive sprocket or drive gear is connected to the crankshaft by a gear or chain. Further, the two shafts are connected to each other by spur gears or helical gears, and rotate in opposite directions. The balance shafts have two shafts, each of which has a weight, which rotates at twice the speed of the engine, thereby canceling the vibration of the second rotation.

Conventionally, the helical gears of the balance shaft module are interlocked with each other to generate noise and vibration.

In this drive system, a backlash compensating gear using a spring force is used to remove a backlash generated between the gears. Such a scissors gear is a state in which a fixed gear and a free- The scissors spring interposed therebetween keeps the contact state at all times by using the elastic force of the spring, in contrast to the rotating direction of the gear to be rotated, thereby eliminating the backlash and reducing the rattle noise.

However, these scissors gears ultimately increase the internal stresses of the system and cause additional problems of deforming the gears.

In particular, even when a helical gear is used, the 3-cylinder balance shaft is always engaged at the same position because the number of gear teeth is the same as that of the crank gear. When the engine is rotated, the gears at the same position always receive uneven loads due to the centrifugal force of the balance weight, In some cases, the noise is increased.

In addition, conventionally, gears and shafts are integrally formed, which makes it difficult to precisely process them, and it is difficult to expect improvement in durability using heat treatment.

KR 10-0643952 B1

SUMMARY OF THE INVENTION The present invention provides a balance shaft module which is constructed in a structure in which a shaft and a gear are separated from each other and includes a shock absorber having an elastic member inserted therein to reduce vibration and noise and to reduce gear wear. It has its purpose.

According to an aspect of the present invention, there is provided a balance shaft module including: a shaft; A shaft base provided on one side of the shaft; A gear detachably mounted on one side of the shaft base; A weight eccentrically installed on the other side of the shaft; A first buffer member mounted between the gear and the shaft base for buffering an impact due to a rotation fluctuation of the gear; And a second buffer member installed on the gear to press the gear and the shaft base.

The first cushioning member is mounted on the gear and has a plurality of spring balls radially extended through the shaft hole. The first cushion member has a first guide groove formed at both ends of the spring ball. A damper spring inserted into the spring hole and provided with a spring seat on both sides thereof and having a second guide groove corresponding to the first guide groove at each end; And a second plate mounted on the shaft base and having a protrusion formed on one side thereof and one end and the other end of the protrusion being inserted into the first guide groove and the second guide groove, And the rotary vibration transmitted to the shaft is damped.

The second cushioning member is provided with a cone spring and a snap ring on the gear, and the gear, the first cushioning member, and the shaft base are pressed against each other to impart a frictional force, thereby reducing a resonance phenomenon that occurs upon starting or stopping the engine .

Wherein the first cushioning member has a plurality of spring grooves into which a damper spring is inserted on a surface where the gear and the shaft base abut; A plurality of damper springs inserted into the spring grooves; And a stopper formed to have a length smaller than that of the damper spring and inserted into the spring groove, so that rotational vibration transmitted from the gear to the shaft is attenuated by the tension of the coil spring.

The second cushioning member is provided with a cone spring and a snap ring on the gear, and the gear and the shaft base are pressed against each other to impart a frictional force, thereby reducing a resonance phenomenon generated when the engine is started or stopped.

The present invention with the above-described configuration can be expected to have the following effects.

First, in addition to the basic performance in which the balance weight counteracts the up-down motion of the engine cylinder, the rotational fluctuation caused by the engine explosive force is reduced, thereby reducing the rattle noise.

The vibration noise in the axial direction that occurs when the helical gear is used to attenuate the noise is also attenuated.

At this time, the vibration generated in the axial direction can be attenuated by using the helical gear.

And the gear and shaft are removable and convenient to manufacture. That is, the material of the gear portion is steel for carburizing heat treatment which has good workability and abrasion resistance, and shaft and weight are convenient for processing and handling by using conventional forging material.

In addition, precision machining of the gears is easy, and improvement in durability can be expected by applying the hardening method using the carburizing heat treatment during the heat treatment.

On the other hand, a cone spring and a snap ring are installed in the gear, and the gear and the shaft are pressed against each other, thereby effectively reducing the resonance occurring at the time of starting or stopping the engine.

1, 2, and 3 are exploded views of a balance shaft module according to a first preferred embodiment of the present invention.
4 is an exploded view of a first buffer member according to a first preferred embodiment of the present invention.
5 is an exploded view of a balance shaft module mainly applied to a three-cylinder engine according to a second preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The balance shaft module according to the present invention is installed to be able to receive a rotational force directly from a crankshaft at a lower side of a crankshaft while being coupled to a lower portion of the engine. As shown in FIG. 1, the shaft 100 includes a shaft 100, A gear 400, a weight 300, a first cushioning member 500, and a second cushioning member 600.

First, the shaft 100 forms an axis of the balance shaft module and is rotated by receiving a rotational force from a gear 400, which will be described later.

Next, the shaft base 200 is circularly formed on one side of the shaft 100 to receive a rotational force.

The gear 400 is detachably mounted on a side surface of the shaft base 200 and receives rotation force from the crank gear of the engine to rotate the shaft base 200.

In this case, it is preferable to apply a helical gear to reduce the whine noise of the gear to increase the engagement ratio.

Next, the weight 300 is eccentrically installed on the other side of the shaft 100, so that the shaft 100 rotates to mitigate the vibration caused by uneven torque of the crankshaft.

1, the weight 300 is formed in a semicircular column shape with an arc surface protruding outward around the shaft at the other side and the middle portion of the shaft 100 according to the first embodiment.

Alternatively, according to the second embodiment, as shown in FIG. 5, the shaft 100 is detachably mounted on the other side of the shaft 100 and is formed to have an arc surface at an angle of less than 180 degrees.

As described above, the weight 300 is provided so as to balance the rotation when the crankshaft rotates, thereby relieving the vibration of the engine.

Next, the first cushioning member 500 is mounted between the gear 400 and the shaft base 200 to reduce vibrations generated in the engine, and to cushion shocks when the gear 400 is suddenly rotated or suddenly stopped.

1, 2, 3, and 4, the first buffer member 500 includes a first plate 520, a damper spring 540, and a second plate (not shown) 560).

The gear 400 and the shaft base 200 are each formed with a plurality of insertion grooves 502 on the surface into which the first buffer member is inserted and are formed on the outer surfaces of the first plate 520 and the second plate 560 A fixing portion 504 corresponding to the insertion groove 502 is formed to protrude. That is, the outer surfaces of the first plate 520 and the second plate 560 are mounted on the gear 400 and the shaft base 200, respectively.

The first plate 520 has a plurality of spring holes 522 formed radially and long through the shaft hole and has a first guide 522 having a width smaller than the width of the spring hole 522 at both ends of the spring hole 522, Grooves 524 are formed long in the longitudinal direction.

On the other hand, the damper spring 540 is inserted into the spring hole 522 to buffer vibrations transmitted from the engine to the balance shaft module by elastic action.

A spring seat 542 is provided at both ends of the damper spring 540 to prevent secondary noise. A second guide groove 544 corresponding to the first guide groove 524 is formed at an end of the spring seat 542, And is inserted into the spring hole 522.

At this time, it is preferable that the spring seat 542 is made of an engineering plastic material to effectively prevent noise.

The second plate 560 has a first guide groove 524 and a protrusion 562 corresponding to the second guide groove 544 formed at one side thereof so that one end and the other end of the protrusion 562 are connected to the first guide And is inserted into the groove 524 and the second guide groove 544.

Therefore, the damper spring 540 is compressed by the rotation of the gear 400 to which the rotational force is applied from the crank gear of the engine, so that the first cushioning member 500 has the effect of buffering the protruding portion 562 when rotating. The weight 300 of the gear 400 and the protrusion 562 due to the inertia of the shaft 100 compress the damper spring 540 to reduce the vibration.

The first cushioning member 500 according to the second embodiment includes a spring groove 510, a damper spring 540, and a stopper 550 as shown in FIG.

At this time, a damper spring 540 is inserted into a surface of the spring groove 510 where the gear 400 and the shaft base 200 abut each other, and a plurality of the spring grooves 510 are radially formed around the shaft hole.

On the other hand, the damper spring 540 absorbs the shock due to the rotation fluctuation of the gear 400 and attenuates the excitation force from the engine.

One side and the other side of the damper spring 540 are inserted into the spring groove 510 of the gear base 400 and the shaft base 200 when the damper spring 540 is divided in the longitudinal direction.

At this time, the stopper 550 is formed to have a smaller length than the damper spring 540 and is inserted into the spring groove 510 alternately with the damper spring 540. The stopper 550 is compressed by the difference in length between the damper spring 540 and the stopper 550 The rotational force is buffered.

Next, the second cushioning member 600 is installed on the gear 400 to press the gear 400 and the shaft base 200.

1 and 5, the second cushioning member 600 is provided with a cone spring 620 and a snap ring 640 at one side of the gear 400 to rotate the gear 400 and the shaft base 200 So as to reduce the resonance phenomenon occurring for a short time when the engine is started or stopped. That is, the second buffer member 600 closely contacts the gear 400 and the shaft base 200 to reduce relative motion between the gear 400 and the shaft base 200, thereby absorbing vibration.

As described above, in the balance shaft module according to the present invention, in addition to the basic performance in which the weight compensates the up-down motion of the engine cylinder, the rotational fluctuation caused by the engine explosive force is reduced, thereby reducing the rattle noise.

Further, the gear 400 and the shaft 100 are removably installed, which is convenient to manufacture. That is, the material for the gear portion employs a steel for carburizing heat treatment having good workability and wear resistance, and the shaft 100 and the weight 300 are convenient for machining and handling by using a conventional forging material.

In addition, it is easy to precisely process the gear 400, and by applying the curing method using the carburizing heat treatment at the time of heat treatment, improvement in durability can be expected.

Meanwhile, the cone spring 620 and the snap ring 640 are installed in the gear 400, and the gear 400 and the shaft 100 are pressed against each other, thereby effectively reducing the resonance occurring at the start or stop of the engine.

The above embodiments are merely illustrative, and various modifications and variations are possible without departing from the scope of the present invention.

Therefore, the true technical protection scope of the present invention should include not only the above embodiments but also various other modified embodiments according to the technical idea of the invention described in the following claims.

100: Shaft
200: shaft base
300: Weight
400: gear
500: first buffer member
502: insertion groove
504:
510: spring groove
520: first plate
522: Spring ball
524: first guide groove
540: Damper spring
542: spring seat
544: second guide groove
550: Stopper
560: second plate
562:
600: second buffer member
620: Cone spring
640: Retaining ring

Claims (5)

A balance shaft module mounted on a cylinder block of an engine,
shaft;
A shaft base provided on one side of the shaft;
A gear detachably mounted on one side of the shaft base;
A weight eccentrically installed on the other side of the shaft;
A first buffer member mounted between the gear and the shaft base for buffering an impact due to a rotation fluctuation of the gear;
And a second buffer member installed on the gear to press the gear and the shaft base. The method according to claim 1,
The first buffer member may include:
A first plate mounted on the gear and having a plurality of spring balls radially extended through the shaft hole and passing through the first guide groove at both ends of the spring hole;
A damper spring inserted into the spring hole and provided with a spring seat on both sides thereof and having a second guide groove corresponding to the first guide groove at each end;
And a second plate mounted on the shaft base and having a protrusion formed on one side thereof and one end and the other end of the protrusion being inserted into the first guide groove and the second guide groove,
And damps the rotational vibration transmitted from the gear to the shaft by the compression force of the damper spring. 3. The method of claim 2,
The second cushioning member
Wherein a cone spring and a snap ring are installed in the gear to reduce friction between the gear, the first buffer member, and the shaft base to generate a frictional force, thereby reducing a resonance phenomenon generated when the engine is started or stopped. The method according to claim 1,
The first buffer member may include:
A plurality of spring grooves into which a damper spring is inserted on a surface where the gear and the shaft base abut;
A plurality of damper springs inserted into the spring grooves;
And a stopper formed to have a length smaller than that of the damper spring and inserted into the spring groove so as to attenuate the rotational vibration transmitted from the gear to the shaft by the tension of the coil spring. 5. The method of claim 4,
The second cushioning member
Wherein a cone spring and a snap ring are installed in the gear to apply a frictional force between the gear and the shaft base to reduce a resonance phenomenon generated when the engine is started or stopped.

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