JP6011971B2 - Power transmission device for vehicle - Google Patents

Description

  The present invention relates to a vehicle power transmission device including a crank type continuously variable transmission that transmits a driving force from an input shaft to an output shaft via a connecting rod that reciprocates and a one-way clutch.

  The large end of the connecting rod is connected to an eccentric disk that rotates integrally with the input shaft connected to the engine, and the small end of the connecting rod is connected to the output shaft via a one-way clutch. A power transmission device for a vehicle that converts a reciprocating motion of a connecting rod generated into a rotational motion in one direction of an output shaft by a one-way clutch is known from Patent Document 1 below.

JP-T-2005-502543

  By the way, in the conventional vehicle power transmission device, the inner race of the ball bearing is press-fitted into the outer peripheral surface of the eccentric disk provided on the input shaft, and the inner peripheral surface of the large end portion of the connecting rod is inserted into the outer race of the ball bearing. Press fit. Since the connecting rod has a connecting part that connects the large end part and the small end part, the rigidity of the large end part of the connecting rod is not constant in the circumferential direction, and the rigidity of the part connected to the connecting part is locally Get higher. Therefore, when the large end of the connecting rod is press-fitted into the outer race of the ball bearing, the outer race that comes into contact with the portion with high rigidity at the large end receives a large press-fitting reaction force, and the outer race that comes into contact with the portion with low rigidity at the large end. The race will receive a small press-fitting reaction force, and the difference in the press-fitting reaction force distorts the ball bearing and lowers the roundness, resulting in increased ball bearing friction and reduced durability. is there.

  In order to avoid this, it is sufficient to increase the rigidity by increasing the thickness of the large end of the connecting rod as a whole. However, if this is done, there is a problem that the weight and dimensions of the connecting rod increase.

  The present invention has been made in view of the above-described circumstances, and ensures the roundness of a bearing that is press-fitted into the large end of the connecting rod while minimizing the increase in the weight of the connecting rod of the vehicle power transmission device. The purpose is to do.

  To achieve the above object, according to the first aspect of the present invention, an input shaft connected to a drive source, an output shaft arranged in parallel to the input shaft, and swingable to the output shaft Is disposed between the swinging link supported by the shaft, the output shaft and the swinging link, and engages when the swinging link swings in one direction and disengages when swinging in the other direction. 1-way clutch, an eccentric disk that rotates eccentrically with the input shaft, a speed change actuator that changes the amount of eccentricity of the eccentric disk, and a connecting rod that connects the eccentric disk and the swing link In the transmission device, the connecting rod includes an annular large end that is press-fitted into a bearing provided on an outer peripheral surface of the eccentric disk, a small end connected to the swing link, and the large end. And a connecting portion for connecting the small end portion, the connecting portion is formed with a through-hole penetrating both surfaces in the axial direction, and the center of the outer peripheral surface of the large end portion is relative to the center of the inner peripheral surface. A vehicular power transmission device is proposed in which an inner edge portion of the through hole that is eccentric to the small end portion and faces the large end portion is an arc that shares the center with the outer peripheral surface.

  According to the invention described in claim 2, in addition to the structure of claim 1, the radius of the inner edge portion of the through hole is smaller than the radius of the outer peripheral surface of the large end portion. A power transmission device is proposed.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, the outer edge portion of the through hole is connected tangentially to the outer peripheral surface of the large end portion. A vehicle power transmission device is proposed.

  The ball bearing 20 of the embodiment corresponds to the bearing of the present invention, and the engine E of the embodiment corresponds to the drive source of the present invention.

  According to the configuration of the first aspect, when the input shaft connected to the drive source rotates, the connecting rod having the large end connected to the eccentric disk that rotates eccentrically integrally with the input shaft reciprocates, and the small size of the connecting rod is reduced. The swing link connected to the end swings back and forth. When the swing link swings in one direction, the one-way clutch is engaged, and when the swing link swings in the other direction, the one-way clutch is disengaged, so that the reciprocating motion of the connecting rod rotates in one direction of the output shaft. Is converted to When the eccentric amount of the eccentric disk is changed by the speed change actuator, the stroke of the reciprocating motion of the connecting rod changes and the swing angle of the swing link changes, so that the rotation of the input shaft is shifted and transmitted to the output shaft.

  The connecting rod includes an annular large end portion that is press-fitted into a bearing provided on the outer peripheral surface of the eccentric disk, a small end portion that is connected to the swing link, and a connecting portion that connects the large end portion and the small end portion. As a result, the rigidity of the connecting rod's large end is locally increased at the portion connected to the connecting part.When the connecting rod's large end is press-fitted into the bearing, the bearing is bent due to imbalance of the press-fitting reaction force. Roundness may be reduced.

  However, the connecting portion of the connecting rod is formed with a through-hole penetrating both surfaces in the axial direction, and the center of the outer peripheral surface of the large end is eccentric to the small end side with respect to the center of the inner peripheral surface. Because the inner edge of the through hole facing the center is an arc that shares the center with the outer peripheral surface, the press-fitting reaction force changes gently in the circumferential direction by preventing the rigidity of the large end from suddenly changing in the circumferential direction. This can increase the roundness of the bearing. In addition, the increase in the weight and dimensions of the connecting rod can be minimized as compared with the case where the entire large end is thickened to increase the roundness of the bearing.

  According to the second aspect of the present invention, since the radius of the inner edge portion of the through hole is smaller than the radius of the outer peripheral surface of the large end portion, the rigidity of the large end portion that is excessive at the portion connected to the connecting portion is reduced. By reducing the radius of the inner edge portion of the hole, the roundness of the bearing can be further increased by making the rigidity of the large end portion uniform in the circumferential direction.

  According to the third aspect of the present invention, the outer edge portion of the through hole is tangentially connected to the outer peripheral surface of the large end portion, so that the change in the thickness of the connecting rod at the portion where the large end portion and the connecting portion are connected is minimized. It is possible to further increase the roundness of the bearing by further uniforming the press-fitting reaction force received by the bearing from the large end in the circumferential direction.

The skeleton figure of the power transmission device for vehicles. FIG. 2 is a detailed view of part 2 of FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (TOP state). FIG. 3 is a sectional view taken along line 3-3 in FIG. 2 (LOW state). The action explanatory view in the TOP state. The action explanatory view in the LOW state. The figure which shows the shape of a connecting rod. The figure which compares roundness of the large end part of embodiment and Comparative Examples 1-3. The figure which compares roundness of the large end part of embodiment and the comparative example 4. The figure which compares embodiment and the comparative example 5. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the vehicle power transmission device for transmitting the driving force of the engine E to the drive wheels W, W via the left and right axles 10, 10 includes a crank type continuously variable transmission T and a differential gear D. Prepare.

  Next, the structure of the continuously variable transmission T will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the continuously variable transmission T of the present embodiment is obtained by superimposing a plurality (four in the embodiment) of power transmission units U... Having the same structure in the axial direction. These power transmission units U are provided with a common input shaft 11 and a common output shaft 12 arranged in parallel, and the rotation of the input shaft 11 is decelerated or increased and transmitted to the output shaft 12.

  Hereinafter, the structure of one power transmission unit U will be described as a representative. The input shaft 11 connected to the engine E and rotates passes through the hollow rotating shaft 14a of the speed change actuator 14 such as an electric motor so as to be relatively rotatable. The rotor 14b of the speed change actuator 14 is fixed to the rotating shaft 14a, and the stator 14c is fixed to the casing. The rotation shaft 14 a of the speed change actuator 14 can rotate at the same speed as the input shaft 11 and can rotate relative to the input shaft 11 at a different speed.

  A first pinion 15 is fixed to the input shaft 11 passing through the rotation shaft 14 a of the speed change actuator 14, and a crank-shaped carrier 16 is connected to the rotation shaft 14 a of the speed change actuator 14 so as to straddle the first pinion 15. The Two second pinions 17, 17 having the same diameter as the first pinion 15 are supported via pinion pins 16 a, 16 a at positions forming an equilateral triangle in cooperation with the first pinion 15, respectively. The first pinion 15 and the second pinions 17, 17 mesh with a ring gear 18 a formed eccentrically inside a disc-shaped eccentric disk 18.

  The connecting rod 19 includes a large end portion 19a, a small end portion 19b, and a connecting portion 19c that connects the large end portion 19a and the small end portion 19b. The large end portion 19a is fitted to the outer periphery of the eccentric disk 18 through a ball bearing 20 so as to be relatively rotatable, and the small end portion 19b has a pin 26 attached to the swing link 13 supported to be swingable on the outer periphery of the output shaft 12. It is pivoted through.

  The one-way clutch 21 disposed between the output shaft 12 and the swing link 13 is an annular outer member 22 press-fitted into the inner peripheral surface of the swing link 13, and is disposed inside the outer member 22 so as to be connected to the output shaft 12. The inner member 23 is fixed, and the rollers 25 are arranged in a wedge-shaped space formed between the outer member 22 and the inner member 23 and are urged by the engagement springs 24.

  As is clear from FIG. 2, the four power transmission units U... Share the crank-shaped carrier 16, but the phase of the eccentric disk 18 supported by the carrier 16 via the second pinions 17 and 17 is the same. Each power transmission unit U differs by 90 °. For example, in FIG. 2, the eccentric disk 18 of the leftmost power transmission unit U is displaced upward in the figure with respect to the input shaft 11, and the eccentric disk 18 of the third power transmission unit U from the left is relative to the input shaft 11. The eccentric discs 18 and 18 of the second and fourth power transmission units U and U from the left are located in the middle in the vertical direction.

  1 to 6 schematically show the shape of the connecting rod 19, the actual shape of the connecting rod 19 will be described in detail with reference to FIG.

  The large end 19a of the connecting rod 19 includes an inner peripheral surface Pa having a radius Ra and an outer peripheral surface Pb having a radius Rb larger than Ra, and the center of the outer peripheral surface Pb with respect to the center Oa of the inner peripheral surface Pa. Ob is biased toward the small end 19b by a distance a. Accordingly, the radial thickness of the large end portion 19a is not uniform in the circumferential direction, the thickness is reduced on the side far from the small end portion 19b, and the thickness is increased on the side close to the small end portion 19b.

  A triangular through hole 19d is formed in the center of the triangular connecting portion 19c so as to penetrate both axial surfaces of the connecting rod 19, and the inner edge Ea where the through hole 19d faces the large end 19a is large. It is comprised by the circular arc of radius Rc which shares the outer peripheral surface Pb and the center Ob of the edge part 19a. The radius Rc of the inner edge Ea of the through hole 19d is set to be smaller than the radius Rb of the outer peripheral surface Pb of the large end 19a by a distance b.

  The connecting portion 19c includes two outer edge portions Eb and Eb that extend while expanding from the small end portion 19b toward the large end portion 19a, and the outer edge portions Eb and Eb are the outer circumferences of the large end portion 19a. It is connected tangentially to the surface Pb.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  First, the operation of one power transmission unit U of the continuously variable transmission T will be described. When the rotation shaft 14 a of the speed change actuator 14 is rotated relative to the input shaft 11, the carrier 16 rotates about the axis L <b> 1 of the input shaft 11. At this time, the center O of the carrier 16, that is, the center of the equilateral triangle formed by the first pinion 15 and the two second pinions 17, 17 rotates around the axis L 1 of the input shaft 11.

  3 and 5 show a state in which the center O of the carrier 16 is on the opposite side of the output shaft 12 with respect to the first pinion 15 (that is, the input shaft 11). The eccentricity is maximized and the ratio of the continuously variable transmission T is in the TOP state. 4 and 6 show a state in which the center O of the carrier 16 is on the same side as the output shaft 12 with respect to the first pinion 15 (that is, the input shaft 11). At this time, the eccentric disk 18 with respect to the input shaft 11 The amount of eccentricity is minimized and the ratio of the continuously variable transmission T is in the LOW state.

  In the TOP state shown in FIG. 5, when the input shaft 11 is rotated by the engine E and the rotation shaft 14 a of the speed change actuator 14 is rotated at the same speed as the input shaft 11, the input shaft 11, the rotation shaft 14 a, the carrier 16, With the one pinion 15, the two second pinions 17 and 17, and the eccentric disk 18 being integrated, the pinion 15 rotates eccentrically around the input shaft 11 (see arrow A). While rotating from the state shown in FIG. 5A through the state shown in FIG. 5B to the state shown in FIG. 5C, the large end 19a is supported on the outer periphery of the eccentric disk 18 via the ball bearing 20 so as to be relatively rotatable. The connecting rod 19 swings the swing link 13 pivotally supported by the pin 26 at the small end portion 19b in the counterclockwise direction (see arrow B). 5A and 5C show both ends of the swing of the swing link 13 in the arrow B direction.

  When the swing link 13 swings in the direction of arrow B in this way, the rollers 25... Engage with the wedge-shaped space between the outer member 22 and the inner member 23 of the one-way clutch 21, and the rotation of the outer member 22 causes the inner member 23 to rotate. , The output shaft 12 rotates counterclockwise (see arrow C).

  When the input shaft 11 and the first pinion 15 further rotate, the eccentric disk 18 in which the ring gear 18a is engaged with the first pinion 15 and the second pinion 17, 17 rotates eccentrically in the counterclockwise direction (see arrow A). While rotating from the state shown in FIG. 5C to the state shown in FIG. 5A, the large end 19a is supported on the outer periphery of the eccentric disk 18 via the ball bearing 20 so as to be relatively rotatable. The connecting rod 19 swings the swing link 13 pivotally supported by the pin 26 at the small end portion 19b in the clockwise direction (see arrow B '). FIGS. 5C and 5A show both ends of the swing of the swing link 13 in the direction of the arrow B ′.

  When the swing link 13 swings in the direction of the arrow B ′ in this way, the rollers 25 are pushed out from the wedge-shaped space between the outer member 22 and the inner member 23 while compressing the engagement springs 24. The outer member 22 slips with respect to the inner member 23 and the output shaft 12 does not rotate.

  As described above, when the swing link 13 reciprocally swings, the output shaft 12 rotates counterclockwise (see arrow C) only when the swing direction of the swing link 13 is counterclockwise (see arrow B). Therefore, the output shaft 12 rotates intermittently.

  FIG. 6 shows the operation when the continuously variable transmission T is operated in the LOW state. At this time, since the position of the input shaft 11 coincides with the center of the eccentric disk 18, the eccentric amount of the eccentric disk 18 with respect to the input shaft 11 becomes zero. In this state, when the input shaft 11 is rotated by the engine E and the rotating shaft 14a of the speed change actuator 14 is rotated at the same speed as the input shaft 11, the input shaft 11, the rotating shaft 14a, the carrier 16, the first pinion 15, 2 In a state where the second pinions 17 and 17 and the eccentric disk 18 are integrated, the input pin 11 is rotated eccentrically in the counterclockwise direction (see arrow A). However, since the eccentric amount of the eccentric disk 18 is zero, the stroke of the reciprocating motion of the connecting rod 19 is also zero, and the output shaft 12 does not rotate.

  Therefore, if the speed change actuator 14 is driven and the position of the carrier 16 is set between the TOP state of FIG. 3 and the LOW state of FIG. 4, operation at an arbitrary ratio between the zero ratio and the predetermined ratio becomes possible.

  In the continuously variable transmission T, the phases of the eccentric disks 18 of the four power transmission units U arranged in parallel are shifted by 90 ° from each other, so that the four power transmission units U are alternately driven. By transmitting, that is, any one of the four one-way clutches 21 is always in an engaged state, the output shaft 12 can be continuously rotated.

  By the way, when the outer peripheral surface of the ball bearing 20 is press-fitted into the inner peripheral surface Pa of the large end portion 19a of the connecting rod 19, the ball bearing 20 generates a press-fitting reaction force radially inward from the inner peripheral surface Pa of the large end portion 19a. Receive and transform. At this time, if the radially inward press-fitting reaction force is uniform in the circumferential direction, the roundness of the ball bearing 20 after press-fitting is ensured, but actually the rigidity of the large end 19a is circumferential. Since the rigidity is locally increased in the vicinity of the portion where the large end portion 19a and the connecting portion 19c are connected, the ball bearing 20 is distorted by the press-fitting load and the roundness is lowered.

  In Comparative Example 1 of FIG. 8, the center Oa of the inner peripheral surface Pa and the center Ob of the outer peripheral surface Pb are made to coincide, and the radius Rb of the outer peripheral surface Pb and the radius Rc of the inner edge Ea are made the same. The thickness of 19a is set small in order to reduce the size and weight, and its weight is 422g.

  In Comparative Example 1, the thickness of the large end portion 19a is thin, and the rigidity of the portion where the large end portion 19a and the connecting portion 19c are connected is locally increased, so that the press-fitting reaction force at that portion is locally increased. As the ball bearing 20 is deformed inward in the radial direction, the roundness is deteriorated to 52.5 μm. The roundness is a difference between the maximum diameter and the minimum diameter of the ball rolling trajectory of the ball bearing 20. In the case of a perfect circle, the roundness is 0 μm, and the larger the value, the worse the roundness. Show.

  Comparative Example 2 is the same as Comparative Example 1 except that the thickness of the large end portion 19a of Comparative Example 1 is increased. In Comparative Example 2, since the thickness of the large end portion 19a is increased, the weight is increased to 918 g, and the radius R2 of the outer peripheral surface Pb of the large end portion 19a is also increased. However, since the rigidity of the large end portion 19a is increased as a whole due to the increase in the wall thickness, and the sudden change in rigidity at the portion where the large end portion 19a and the connecting portion 19c are connected is mitigated, the roundness is greatly reduced. To 12.5 μm.

  In Comparative Example 3, the center Ob of the outer peripheral surface Pb is shifted to the small end portion 19b side with respect to the center Oa of the inner peripheral surface Pa of the large end portion 19a of Comparative Example 2, and the weight is Comparative Example 1 and Comparative Example. It becomes 640g in the middle of 2. Since the thickness of the portion where the large end portion 19a and the connecting portion 19c are connected is increased and the sudden change in rigidity is further alleviated, the roundness is further reduced to 9.5 μm. However, since the rigidity imbalance still remains in the portion where the large end portion 19a and the connecting portion 19c are connected in Comparative Example 3, the roundness is impaired.

  In the embodiment, the radius Rc of the inner edge portion Ea of the through hole 19d of Comparative Example 3 is made smaller than the radius Rb of the outer peripheral surface Pb, and the rigidity of the portion where the large end portion 19a faces the inner edge portion Ea is locally reduced. ing. Thereby, the weight of the connecting rod 19 of the embodiment is suppressed to 625 g, and the roundness is improved to 3.8 which is better than any of Comparative Examples 1 to 3.

  FIG. 9 illustrates the effect of the through hole 19d. In Comparative Example 4 shown in FIG. 9B, the portion corresponding to the through hole 19d of the embodiment is not penetrated, and the thin web 19e is closed. It is. It can be seen that the web 19e significantly increases the rigidity of the large end 19a facing the inner edge Ea of the through hole 19d, and the roundness is greatly deteriorated. On the other hand, in the embodiment shown in FIG. 9A, by forming the through hole 19d, the rigidity of the large end portion 19a facing the inner edge portion Ea of the through hole 19d is lowered, and the roundness is greatly improved. I understand that.

  FIG. 10 illustrates the effect of the outer edge portions Eb and Eb of the connecting portion 19c. In Comparative Example 5 shown in FIG. 10B, the outer edge portions Eb and Eb of the connecting portion 19c are the outer peripheral surface Pb of the large end portion 19a. They are not connected tangentially, but are connected so as to intersect. As a result, there is a problem that the wall thickness of the large end portion 19a changes suddenly in the vicinity of the intersection, and the roundness deteriorates due to the sudden change in rigidity. On the other hand, in the embodiment shown in FIG. 10A, the outer edge portions Eb and Eb of the connecting portion 19c are tangentially connected to the outer peripheral surface Pb of the large end portion 19a. A sudden change in wall thickness is prevented and roundness is improved.

  As described above, according to the present embodiment, the ball bearing 20 is press-fitted into the large end portion 19a by making the rigidity of the large end portion 19a uniform in the circumferential direction while minimizing an increase in the weight of the connecting rod 19. Thus, it is possible to secure a roundness and to reduce friction and improve durability.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the bearing of the present invention is not limited to the ball bearing 20 of the embodiment, and may be an arbitrary bearing such as a needle bearing, a roller bearing, or a plain bearing.

  The drive source of the present invention is not limited to the engine E of the embodiment, and may be any drive source such as a motor / generator.

DESCRIPTION OF SYMBOLS 11 Input shaft 12 Output shaft 13 Swing link 14 Shifting actuator 18 Eccentric disk 19 Connecting rod 19a Large end 19b Small end 19c Connecting portion 19d Through hole 20 Ball bearing (bearing)
21 One-way clutch E Engine (drive source)
Ea Inner edge Eb of the through hole Outer edge Oa of the connecting portion Center Ob of the inner peripheral surface of the large end portion Center Pa of the outer peripheral surface of the large end portion Pa Inner peripheral surface Pb of the large end portion Large outer peripheral surface Rb of the large end portion Radius Rc of the outer peripheral surface of the inner radius of the through hole

Claims (3)

An input shaft (11) connected to the drive source (E);
An output shaft (12) arranged parallel to the input shaft (11);
A swing link (13) supported swingably on the output shaft (12);
Arranged between the output shaft (12) and the swing link (13) and engaged when the swing link (13) swings in one direction and disengaged when swings in the other direction. A one-way clutch (21) to perform,
An eccentric disk (18) that rotates eccentrically integrally with the input shaft (11);
A speed change actuator (14) for changing the amount of eccentricity of the eccentric disk (18);
A vehicle power transmission device comprising a connecting rod (19) connecting the eccentric disk (18) and the swing link (13),
The connecting rod (19) includes an annular large end (19a) that is press-fitted into a bearing (20) provided on the outer peripheral surface of the eccentric disc (18), and a small link that is connected to the swing link (13). An end (19b) and a connecting portion (19c) for connecting the large end (19a) and the small end (19b);
The connecting portion (19c) is formed with a through hole (19d) penetrating both axial surfaces, and the center (Ob) of the outer peripheral surface (Pb) of the large end portion (19a) is the inner peripheral surface (Pa). The inner edge (Ea) of the through hole (19d) that is eccentric to the small end (19b) side with respect to the center (Oa) and faces the large end (19a) is centered on the outer peripheral surface (Pb) ( The vehicle power transmission device is a circular arc that shares Ob).   The radius (Rc) of the inner edge (Ea) of the through hole (19d) is smaller than the radius (Rb) of the outer peripheral surface (Pb) of the large end (19a). Vehicle power transmission device.   3. The vehicle power according to claim 1, wherein an outer edge portion (Eb) of the through hole (19 d) is tangentially connected to an outer peripheral surface (Pb) of the large end portion (19 a). Transmission device.

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