JP6686811B2 - Balancer system synchronous gear - Google Patents

Description

  The present invention relates to a synchronous gear of a balancer system.

  In recent automobiles, the use of diesel engines is increasing, and the pistons are becoming larger in diameter and longer in stroke, so engine vibration tends to increase. Therefore, many techniques for reducing engine vibration have been proposed. Among them, as a mechanism for actively reducing vibration, there is a balancer system including two eccentric shafts and a synchronous gear that rotationally drives them.

  Steel gears are often used as the synchronous gears of the balancer system, but there are some problems such as high noise and difficulty in weight reduction.

  Patent Document 1 discloses a phenol resin gear including a metal bush and a tooth component member made of a reinforcing material impregnated with a phenol resin.

  In Patent Document 2, a second gear attached to face the first gear has a stopper rubber, and a recess provided in the first gear has a recess. The recess is a portion where lubricating oil is accumulated. There is disclosed a damper structure of a gear device, which is formed so as to face a stopper rubber.

  In Patent Document 3, an outer peripheral portion of a gear including a tooth portion is composed of an inner core portion made of a resin material having a high elastic modulus and high strength, and a surface layer portion made of a resin material having a low elastic modulus covering the inner core portion. A resin gear is disclosed.

JP-A-02-241729 JP, 2014-74467, A JP, 2008-151277, A

  The phenol resin gear described in Patent Document 1 has a configuration in which the resin and the reinforcing material are evenly distributed in the rotation direction of the gear, and when the torque received by the gear varies, when the torque increases. It was not designed to deal with the stress inside the gear and the impact noise that occurs.

  In the configuration described in Patent Document 2, there are problems that the number of parts is large and the cost increase is unavoidable, and the rotation of the gear is greatly disturbed when the elastomer is deteriorated and damaged.

  In the configuration described in Patent Document 3, when the elastomer deteriorates and is damaged, there is a possibility that the rotation of the gear is greatly disturbed, there is no constraint in the axial direction of the gear, and the like.

  In the balancer system, since the crank and the synchronous gear rotate in synchronization, the teeth of the synchronous gear that mesh with each other at the moment when the torque that varies in synchronization with the rotation of the crank becomes maximum are the same each time. For this reason, if the operation that causes an overload with respect to the strength of the gear is continued, there is a high possibility that the meshed teeth will be damaged at the above-described moment of maximum torque.

  The object of the present invention is made in view of the above-mentioned point, and in the synchronous gear of the balancer system, only the tooth that receives a high load is strengthened to improve the reliability and the weight of the other teeth is reduced. To reduce the weight of the entire gear.

  The synchronous gear of the balancer system of the present invention includes a high-strength tooth portion formed of a high-strength material, a resin tooth portion formed of a resin material, and a resin support portion formed of a resin material.

  According to the present invention, in the synchronous gear of the balancer system, it is possible to increase the strength of only the tooth that receives a high load and improve the reliability, and reduce the weight of the other tooth to reduce the weight of the entire gear. it can.

It is a schematic diagram showing arrangement of a synchronous gear of a balancer system. It is a figure which shows the relationship between the torque fluctuation in the synchronous gear of a balancer system, and the meshing position of a synchronous gear. FIG. 3 is a front view showing the synchronous gear of the first embodiment. It is a front view showing a synchronous gear of Example 2. It is a front view which shows the synchronous gear of Example 3. It is a front view which shows the synchronous gear of Example 4. It is a partial expanded sectional view which shows the tooth part of the synchronous gear of Example 5. It is a partial expanded sectional view which shows the tooth | gear part of the synchronous gear of Example 6. It is a partially expanded perspective view which shows the tooth | gear part of the synchronous gear of Example 7. It is a partially expanded perspective view which shows the tooth | gear part of the synchronous gear of Example 8. It is a partially expanded perspective view which shows the tooth | gear part of the synchronous gear of Example 9.

  The present invention relates to a synchronous gear that is a component of a balancer system (also referred to as “balancer gear system”) attached to an engine of an automobile or the like, and more particularly to a synchronous gear that rotationally drives an eccentric shaft. is there.

  First, the synchronous gear of the balancer system attached to the crankshaft connected to the piston of the engine will be described.

  FIG. 1 shows the main components from the engine to the synchronous gears of the balancer system.

  In the figure, the engine 1 represents one of four reciprocating internal combustion engines. A piston 10 is installed in the cylinder 2 of the engine 1. A small end portion 13 of a connecting rod 12 is rotatably connected to a piston pin 11 of the piston 10. The large end portion 14 of the connecting rod 12 is rotatably connected to the crank pin 21 of the crank shaft 20.

  The crankshaft 20 includes a crankpin 21, a crank arm 22, a crank journal 23, and a counterweight 24. The crank pin 21 is connected to the crank arm 22. Further, the crank arm 22 is connected to the crank journal 23. The crank journal 23 is rotatably supported by the crank bearing 4. A flywheel 30 is attached to the crankshaft 20. A tooth row (not shown) is formed on the outer peripheral portion of the flywheel 30. A gear of a starter (not shown) is arranged so as to mesh with the tooth row.

  A drive gear 40 is further attached to the crankshaft 20. A synchronous gear 50a is arranged on the drive gear 40 so as to engage with each other. Further, the synchronous gear 50a is arranged so as to mesh with the synchronous gear 50b. The synchronous gears 50a and 50b have a diameter half that of the drive gear 40.

  With the explosion of fuel inside the cylinder 2, the piston 10 reciprocates in the Y-axis direction shown by the alternate long and short dash line. In the case of a four-cylinder reciprocating internal combustion engine, explosion occurs twice while the drive gear 40 makes one rotation, so the synchronous gears 50a and 50b make one rotation while the drive gear 40 makes one half rotation. Since the explosion occurs once while the synchronous gears 50a and 50b make one revolution, the teeth of the synchronous gears 50a and 50b that receive a large torque generated by the explosion are the same each time.

  The torque received by the synchronous gears of the balancer system will be further described.

  FIG. 2 is a graph showing a temporal change of torque in the synchronous gears of the balancer system and corresponding meshing positions of the two synchronous gears.

  In the graph of this figure, the horizontal axis represents the time when the synchronous gear is rotating, and the vertical axis represents the torque received by the synchronous gear.

  The torque (fluctuation torque) generated by the explosion in the cylinder of the engine is pulse-like, as shown in the graph of this figure. When the torque becomes maximum, the same teeth of the two synchronous gears 101 contact. This torque is a force that pushes the teeth in the circumferential direction of the synchronous gear 101. When the torque is at a minimum, the teeth that experience the maximum torque are in the furthest apart.

  Hereinafter, a specific gear configuration will be described using examples.

  FIG. 3 shows a synchronous gear of the balancer system of this embodiment (synchronous gear for balancer system).

  In the figure, a synchronous gear 101 is made of a steel annular ring 102 that is a fitting portion with a shaft, and a steel annular ring 102 (also simply referred to as “annular ring”) that is made of steel and is extended in a radial direction. Gear structure portion 103 (also referred to as “steel support portion” or “high strength support portion”) and steel tooth 104 (“steel tooth portion” or “high strength tooth portion” integrated with steel gear structure portion 103). ).), A resin gear structure portion 105 (resin support portion) in contact with the steel circular ring 102, and resin teeth 106 (resin tooth portion) integrated with the resin gear structure portion 105. Has been done. In other words, the resin gear structure 105 and the resin teeth 106 are integrally molded. Here, the portions formed of the same material and in contact with each other can be produced by casting, forging, shaving, sintering, powder metallurgy or molding as one part. In the present embodiment, the steel teeth 104, the steel gear structure 103, and the steel annular ring 102 are integrated. Therefore, the steel ring 102, the steel gear structure 103, and the steel teeth 104 can be manufactured as one part. The resin gear structure 105 and the resin teeth 106 can be manufactured as one part. It is more advantageous to manufacture in this way in terms of manufacturing cost. The steel teeth 104 and the steel gear structure 103 may be integrated, except for the steel annular ring 102. Further, the steel annular ring 102, the steel teeth 104, and the steel gear structure portion 103 may be separately manufactured and then combined. In this case, the separately manufactured parts may be joined by screwing or welding, or may be joined by fitting using a key.

  An aramid fiber reinforced resin or the like is used as the resin material forming the resin gear structure portion 105 and the resin teeth 106.

  When the two synchronous gears 101 are incorporated into the balancer gear, they are attached so that the steel teeth 104 are aligned with each other in the phase in which the crank torque is maximized. With respect to the rotation center of the synchronous gear 101, the opening angle of the entire steel teeth 104 is preferably 30 to 45 degrees, and more preferably 30 to 40 degrees.

  In the above configuration, when the engine is driven to rotate and the synchronous gear 101 is rotated, as shown in FIG. 2, the steel teeth 104 mesh with each other in the phase where the torque becomes maximum, and the resin teeth 106 mesh with each other in the range where the torque is small. It will be. As a result, in response to torque fluctuations synchronized with the rotation of the crank, the steel teeth 104 transmit power in the high torque range and the resin teeth 106 transmit power in the low torque range. Therefore, it is possible to prevent the resin teeth 106 from being overloaded, and it is possible to obtain the effect of suppressing noise in the range where the resin teeth 106 are engaged with each other.

  In the present embodiment, the case where the two synchronous gears connected to the drive gear are made of steel and resin material has been described, but one of the synchronous gears may be a gear made entirely of steel. .

  Further, in the present embodiment, a part of the synchronous gear 101 is made of steel, but the present invention is not limited to this, and the part made of steel is made of a resin material forming the resin teeth 106. May be formed of metal, resin material, ceramics or the like having high strength. Examples of high-strength resin materials include carbon fiber reinforced plastic (CFRP) and glass fiber reinforced plastic (GFRP). It should be noted that metals, resin materials, ceramics and the like having higher strength than the resin material forming the resin teeth 106 are collectively referred to as “high strength material” in the present specification. The high-strength material is a material having higher strength than the resin material forming the resin teeth 106.

  Further, in the present embodiment, the size of the steel tooth 104 is the same as the width and thickness of the tooth, but the present invention is not limited to this, and the size of the steel portion is smaller than the width or thickness of the tooth. However, a part may be made of a resin material. Further, the thickness of the steel gear structure 103 is also the same as the thickness of the teeth, but the thickness is not limited to this, and the dimension of the steel portion is made smaller than the thickness of the teeth, and a part is made of a resin material. You may comprise.

  Further, in this embodiment, the shape of the steel gear structure 103 is a fan shape, but the shape is not limited to this, and may be a rectangular shape or a shape in which the width becomes narrower toward the teeth. It may be.

  Furthermore, if the strength is sufficient, a through hole or a recess may be provided in a part of the steel gear structure 103. As a result, the weight of the synchronous gear 101 can be reduced.

  It should be noted that the present invention is applicable even if the steel gear structure 103 is not provided.

  FIG. 4 shows a synchronous gear of the balancer system of this embodiment.

  Only the points different from the first embodiment will be described.

  In this figure, an elastomer 111 is embedded in a part of the resin gear structure 105. The elastomer 111 has a columnar shape and penetrates the resin gear structure 105. In other words, the elastomer 111 is embedded in the through hole of the resin gear structure 105.

  As a modification, the elastomer 111 does not penetrate the resin gear structure 105. That is, a configuration may be adopted in which the elastomer 111 having the shape shown in the figure is embedded in the recess provided in the resin gear structure 105.

  In addition, although the shape of the elastomer 111 is a cylindrical shape in this figure, the shape of the elastomer 111 is not limited to this, and may be, for example, a triangular shape, a quadrangular shape, or another polygonal shape. Further, it may have an elliptical shape, a donut shape, or the like. Examples of the elastomer 111 include, but are not limited to, nitrile rubber and silicone rubber.

  In the present embodiment, the elastomer 111 is provided at every 90 degrees, but the present invention is not limited to this, and for example, many elastomers 111 may be arranged near the steel gear structure 103. The elastomer 111 may be arranged in a biased manner. Further, in the present embodiment, the elastomer 111 is in contact with only the resin gear structure portion 105.

  The through hole or the concave portion of the resin gear structure portion 105 can be freely formed by providing a convex portion or the like corresponding to the through hole or the concave portion in the mold when molding the resin gear structure portion 105 using a mold. You can Of course, the through hole or the recess may be provided by processing with a drill or the like after molding.

  FIG. 5 shows a synchronous gear of the balancer system of this embodiment.

  Only points different from the second embodiment will be described.

  In the figure, the shape of the elastomer 121 is an arc shape. The elastomer 121 may be embedded in a groove provided in the resin gear structure 105, or may have a structure penetrating to the back surface of the resin gear structure 105.

  In addition, although the shape of the elastomer 121 is a continuous arc shape in this figure, the shape of the elastomer 121 is not limited to this and may be, for example, a discontinuous arc shape.

  FIG. 6 shows a synchronous gear of the balancer system of this embodiment.

  Only differences from the third embodiment will be described.

  In this figure, the shape of the elastomer 131 is an annular shape. The elastomer 131 is embedded not only in the resin gear structure 105 but also in the groove provided in the steel gear structure 103.

  Hereinafter, an example in which one tooth includes a high-strength tooth and a resin tooth will be described.

  FIG. 7 is an enlarged view of the teeth of the synchronous gear of the balancer system of this embodiment.

  In this figure, the tooth portion 151 has a configuration in which the entire surface of the steel tooth portion 152 is covered with a resin tooth portion 153.

  FIG. 8 is an enlarged view of the tooth portion of the synchronous gear of the balancer system of this embodiment.

  In the figure, the tooth portion 151 has a structure in which a part of the surface of the steel tooth portion 152 is covered with a resin tooth portion 153. The surface of the tooth portion 151 on the side receiving the fluctuating torque is required to have the highest strength, and therefore has a structure in which the steel is exposed.

  Further, as a modification, the resin tooth portion 153 may be provided on the surface of the tooth portion 151 on the side that receives the fluctuating torque. In this case, since the resin material receives the fluctuating torque, it is possible to reduce the noise generated in the collision.

  FIG. 9 is an enlarged view of the teeth of the synchronous gear of the balancer system of this embodiment.

  In this drawing, the steel tooth portion 152 is sandwiched between the resin tooth portions 153 in the thickness direction of the tooth portion 151. In this case, by making the width and height of the steel tooth portion 152 smaller than that of the resin tooth portion 153, it is possible to avoid steel collision and reduce noise. In this case, the difference in width and height between the steel tooth portion 152 and the resin tooth portion 153 is effective even if it is about 0.1 to 0.2 mm.

  FIG. 10 is an enlarged view of the teeth of the synchronous gear of the balancer system of this embodiment.

  In this figure, the resin tooth portion 153 is sandwiched between the steel tooth portions 152 in the thickness direction of the tooth portion 151. In other words, a recess is provided in the central portion of the steel tooth portion 152 in the thickness direction, and the resin tooth portion 153 is filled in the recess. Also in this case, by making the width and height of the steel tooth portion 152 smaller than that of the resin tooth portion 153, it is possible to avoid steel collision and reduce noise.

  FIG. 11 is an enlarged view of the end surface of the tooth portion of the synchronous gear of the balancer system of this embodiment (the portion farthest from the rotary shaft of the synchronous gear).

  In this figure, a cross-shaped steel tooth portion 152 is provided at the core of the tooth portion 151, and resin tooth portions 153 are provided at the four corners of the tooth portion 151. Also in this case, by making the width and height of the steel tooth portion 152 smaller than that of the resin tooth portion 153, it is possible to avoid steel collision and reduce noise.

  1: Engine, 2: Cylinder, 10: Piston, 11: Piston pin, 12: Connecting rod, 13: Small end, 14: Large end, 20: Crankshaft, 21: Crankpin, 22: Crank arm, 23 : Crank journal, 24: counter weight, 30: flywheel, 40: drive gear, 50a, 50b, 101: synchronous gear, 102: steel ring, 103: steel gear structure part, 104: steel tooth, 105 : Resin gear structure part, 106: Resin teeth, 111, 121, 131: Elastomer.

Claims (11)

High-strength teeth formed of high-strength material,
Resin teeth made of resin material,
A resin support portion formed of a resin material,
A high-strength support portion formed of a high-strength material,
And the circular is a fitting portion of the shaft, only including,
The ring is made of a high-strength material,
The high-strength tooth portion, the high-strength support portion, and the annular ring are one piece,
The high-strength support is one,
The high-strength tooth portion and the high-strength support portion are synchronous gears of a balancer system having a predetermined opening angle in a rotation direction . The synchronous gear of the balancer system according to claim 1 , wherein
The synchronous gear of the balancer system, wherein the width or thickness of the high-strength tooth portion is smaller than the width or thickness of the high-strength support portion. A synchronous gear of the balancer system according to claim 1 or 2 , wherein
The synchronous gear of a balancer system, wherein the high-strength material has higher strength than the resin material. A synchronous gear of the balancer system according to any one of claims 1 to 5 ,
The synchronous gear of the balancer system, wherein the high-strength material is steel. A synchronous gear of the balancer system according to any one of claims 1 to 5 ,
Furthermore, the synchronous gear of a balancer system containing the elastomer embedded in the said resin support part. The synchronous gear of the balancer system according to claim 5 ,
The elastomer is a synchronous gear of a balancer system, which has a cylindrical shape, an annular shape, an arc shape, a polygonal shape, or an elliptical shape. A synchronous gear of the balancer system according to claim 5 or 6 , wherein
The elastomer is a synchronous gear of a balancer system, which is eccentrically arranged. A synchronous gear of the balancer system according to any one of claims 8 to 9 ,
The elastomer is a synchronous gear of a balancer system, which is in contact with only the resin supporting portion. A synchronous gear of the balancer system according to any one of claims 1 to 9 ,
The synchronous gear of the balancer system, wherein the resin support portion and the resin tooth portion are integrally molded. A synchronous gear of the balancer system according to any one of claims 1 to 9 ,
The synchronous gear of the balancer system, wherein the resin material is an aramid fiber reinforced resin. A synchronous gear of the balancer system according to any one of claims 1 to 10 ,
A synchronous gear of a balancer system, wherein one tooth includes the high-strength tooth and the resin tooth.

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