KR19990021823A - Continuously variable transmission for vehicles - Google Patents

Abstract

The present invention can reliably transfer the power transmitted from a vehicle engine or the like to the drive shaft and the driven shaft by engagement of the gears, The present invention relates to a continuously variable transmission for a vehicle which is capable of fine and flexible change of a rotational speed of a first sun gear and a second sun gear, Fixed deceleration means for decelerating the rotational speed of the power generated by the power generating means at a predetermined ratio, the first planetary gear set being provided so as to be meshed with the first sun gear and the first ring gear; Continuously variable transmission means for flexibly shifting the rotational force output to said first ring gear by revolving said first planetary gear group in the same direction as the rotational direction of said first sun gear; And forward / reverse speed increasing means for increasing the rotational speed of the output shaft from the first ring gear to increase the rotation direction of the output shaft in accordance with forward / backward cauterization of the driver.

Description

Continuously variable transmission for vehicles

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a transmission of a vehicle, and more particularly to a continuously variable transmission for a vehicle that steplessly and continuously changes the rotational force applied from an engine or the like.

There are two main types of transmissions that are used in existing automobiles: passive five-speed and automatic four-speed.

First, when a manual five-speed transmission is used, the shift operation can be performed from the first stage to the fifth stage by the operation of the driver, but there is an inconvenience that the shift operation accompanied with the clutch pedal operation must be performed at each shifting.

The conventional automatic four-stage system is composed of a torque converter, an oil pump, a plurality of planetary gears, a manual valve, several solenoid valves, several hydraulic clutches, hydraulic brakes, hydraulic circuits, sun gear shaft, a planetary gear shaft, or a ring gear shaft. In this type of technology, by detecting the engine output, the speed, the temperature, the throttle valve state, and the like, and automatically shifting to the electronic control using the result calculated by the controller (commonly referred to as TCU), the operational discomfort However, it is disadvantageous in that the structure is very complicated, the manufacturing cost is high, and the energy consumption is reduced by causing an additional fuel consumption of about 10 to 15% in comparison with the manual type.

Particularly, the shift operation of the conventional manual and automatic transmission is performed step by step, and the speed ratio difference between the respective stages is very large, so that it is possible to accelerate or decelerate the vehicle in various modes There is no disadvantage.

For example, when the vehicle climbs up a hill having an arbitrary inclination angle (ten?), The engine output becomes insufficient if the transmission gear is changed to four speeds, while the situation where the output remains when the speed is three speeds can be easily assumed. However, in the conventional case, since an appropriate intermediate stage corresponding thereto is not set, it is inevitably necessary to operate the vehicle in three stages.

In other words, since there are only four or five choices of shift, the problem of unnecessary fuel waste due to the transmission ratio nonconformity to the driving conditions such as road conditions can not be excluded. In particular, In the case of the city, not only the shift is accelerated four to five times at each start, but the shift is made even during driving, the fuel consumption at the time of acceleration is very large, and the economic loss such as unnecessary exhaust gas and noise is too large .

Meanwhile, in order to solve the problems of the conventional vehicular transmission described above, there have been various attempts, for example, a continuously variable transmission using the operation principle shown in FIG. 1 will be briefly described.

1A and 1B are schematic diagrams illustrating the operation principle of a conventional stepless transmission.

The continuously-variable transmission shown in Fig. 1 employs a structure in which power is transmitted by a belt. For reference, this technology has been applied by Ford of the United States to small vehicles with a displacement of about 1600cc.

The principle and characteristics of this transmission are as follows.

This transmission uses a V-form steel belt 1 having a high wear resistance of the surface. The V-form steel belt 1 has a structure in which the rotational force of the engine-side drive pulley 3 is transmitted to the driven pulley- (5). The grooves of the drive pulley 3 and the driven pulley 5 are controlled in accordance with the running state and the required output so that the groove width of the pulley engaged with the belt 1 is reduced or increased, So as to increase or decrease the diameter of the pulley on which the pulleys extend.

That is, the groove width on the side of the drive pulley 3 is widened so that the diameter of the pulley on which the V belt 1 spans is reduced in the axial center direction and the groove width on the driven pulley 5 side is narrowed, The diameter of the driven pulley on which the drive pulley is wound is extended by the reduced length on the drive pulley side.

By using this principle, the transmission ratio is made stepless and automatic control.

However, such a conventional continuously variable transmission also has the following problems.

First, as described above, there is a problem in that the power transmission method using the belt can not completely eliminate the slip phenomenon, resulting in power loss. That is, when the belt is used for a long period of time, a slip phenomenon occurs due to abrasion of the belt and the pulley, and when a foreign matter such as oil, water, dust enters the belt and the pulley, And the power transmission efficiency is lowered.

In addition, as described above, it is very difficult to precisely control the belt contact surfaces (pitch circle) of the drive side pulleys and the driven side pulleys to be reduced or enlarged in a precise and opposite manner to each other. There is a restriction that it can not be applied to the shifting device to be performed.

For reference, inventions using this principle include a continuously variable continuously variable transmission of Patent Publication No. 93-10897 (Nov. 17, 1993), a continuously variable transmission of Patent Publication No. 95-2991 (March 29, 1995) There are many.

In addition, in the variable pitch type continuously variable transmission of Japanese Patent Application No. 96-12241 (Sep. 18, 1996), the principle of FIG. 1 for varying the pitch circle is applied, but in order to solve the problems of the prior art, The pitch diameter of the sprocket is varied and the distance between the axles of both chain supporting the chain is adjusted to obtain a continuously variable transmission effect. However, this case also contributes to solving the problem of occurrence of slip at the time of using the belt, but it is also possible to provide a pitch adjusting frame and a chain variable rod which are provided so as to pass through the teeth of the sprocket, It is difficult to fabricate it because it is precisely assembled to a fine structure, and there is still a problem that the application of a large power for a long time shift device is inadequate because of its limit of durability.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the related art, and it is an object of the present invention to provide a vehicular drive system capable of reliably transmitting power transmitted from a vehicle engine, And to provide a stepless transmission for a vehicle that allows the transmission ratio to be changed finely and continuously in an appropriate manner for an environment that is converted into a time-variant transitional state.

Figs. 1A and 1B are schematic views for explaining the operation principle of a conventional vehicular continuously variable transmission. Fig.

The second aspect of the present invention is a schematic view showing the structure of an embodiment of a continuously variable transmission for a vehicle according to the present invention.

Fig. 3 is a cross-sectional view of Fig. 2; Fig.

FIG. 4 is an explanatory view of the operation principle of the continuously-variable shifting portion of FIG. 2;

5 is a conceptual diagram for explaining the continuously-variable shifting principle of the continuously-variable shifting portion of FIG. 2;

6A to 6C are schematic views for explaining shifting operation of the continuously-variable transmission portion of Fig. 2;

7 is a comparative graph showing operational characteristics of a continuously variable transmission for a vehicle and a conventional continuously variable transmission according to the present invention.

Description of the Related Art [0002]

100: Power transmission intermittent part 200:

300: forward /

110: input shaft 120: torque converter

130: Oil pump 210: Controller (TCU)

220: Speed control motor 230: Warm

240: Worm gear 250: One-way clutch

260: first carrier 261: carrier hollow shaft

263: planetary gear support shaft 270: first sun gear

271: sun gear drive shaft 280: first planetary gear

290: first ring gear 291: inner surface of ring gear

290: ring gear shaft 310: second carrier

311: carrier drive shaft 313: planetary gear support shaft

320: second planetary gear 330: second sun gear

331: Sun gear hollow shaft 340:

350: Drum 360: Third planetary gear

370: second ring gear 373: ring gear hollow shaft

380: cylinder 390: third sun gear

410: Solenoid valve 420: Manual valve

430: Governer 440: Parking locker

450: output shaft

In order to achieve the above object, the present invention provides a vehicular continuously variable transmission that steplessly and continuously shifts a rotational force generated by a power generating means of a vehicle, wherein the rotational force generated by the power generating means A first ring gear which is installed to be driven to receive a rotational force from the first sun gear and a second sun gear which is installed to be coupled between the first sun gear and the first ring gear and which transmits a first power Fixed deceleration means that includes a planetary gear group and decelerates the rotational speed of the power generated by the power generating means at a constant rate; Continuously variable transmission means for flexibly shifting the rotational force output to said first ring gear by revolving said first planetary gear group in the same direction as the rotational direction of said first sun gear; And forward and reverse speed increasing means for increasing and increasing the rotational force output from the first ring gear and switching the rotational direction of the output shaft in accordance with the forward and backward operation of the driver.

Further, the present invention is characterized in that the first group of planetary gears includes three planetary gears disposed at angular intervals of substantially 120 degrees about the first sun gear.

In addition, the present invention is characterized in that the first group of planetary gears includes three to six planetary gears disposed at angular intervals of substantially 120 degrees about the first sun gear.

Further, the present invention is characterized in that the continuously-variable transmission means comprises: auxiliary power supply means capable of controlling the output rotational speed; A worm that receives power from the auxiliary power providing means and rotates; A first carrier which is integrally formed with the hollow shaft and is fitted on the first sun gear shaft and supports the first planetary gear group so as to revolve; A worm gear which is disposed on one side of the hollow shaft of the first carrier and fitted to the worm so as to receive power from the worm and rotate the first carrier; And power transmission interrupting means for interrupting power transmission by temporarily releasing engagement between the first carrier hollow shaft and the worm gear in order to prevent the rotational force of the auxiliary power providing means from flowing back to the first sun gear side .

In addition, the present invention is characterized in that the twist angle of the worm is formed at a predetermined angle, and is slef-locked so as not to be rotated by a force applied from the worm gear.

Further, according to the present invention, the forward / backward speed increasing means may include: a second carrier that rotates the drive shaft directly to the first ring gear shaft; A second and a third group of planetary gears rotated while being respectively supported by the planetary gear support shafts of the second carrier; A second sun gear positioned at a center of the planetary gears of the second group of planetary gears so as to receive rotational force; A drum integrally formed with the second sun gear and integrally coupled to the other end of a second sun gear shaft which is formed as a hollow shaft and through which the second carrier drive shaft penetrates; A first cylinder selectively braking the drum to prevent it from rotating; A third sun gear fixed to the planetary gears of the third planetary gear group and integrally coupled to the output shaft, The third sun gear shaft is coupled to the inside of the third sun gear shaft so as to penetrate therethrough, and the second sun gear shaft is installed on the outer side of the first sun gear shaft, A second ring gear on which a drum is formed; And a second cylinder for selectively braking the second ring gear so as not to rotate.

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

Fig. 2 is a schematic view for explaining the structure of an embodiment of the continuously variable transmission of the present invention, and Fig. 3 is a sectional view of Fig. 2. Fig.

The continuously-variable automatic transmission according to the present embodiment mainly includes a power transmission interrupter 100, a continuously-variable transmission portion 200, and a forward / rearward speed increasing portion 300.

The power transmitting and interrupting unit 100 includes a known torque converter 120 and an oil pump 130 connected to the input shaft 110 to transmit rotational force through a fluid.

The continuously-variable transmission portion 200 includes a first sun gear 270 receiving power from the drive shaft 271, a first group of planetary gears meshed around the first sun gear at predetermined intervals, A plurality of planetary gears 28 that form a group of planetary gears 28 and a plurality of planetary gears 28 that are arranged in such a manner that their inner circumferential gears 291 are meshed with each other, A worm 230 and a worm gear 240 for providing a driving force to the first carrier and a worm 230 for providing a driving force to the first carrier, , And a speed control motor (220) as an auxiliary power for driving the worm (230).

In the case of this embodiment, three planetary gears 280 arranged at intervals of 120 degrees are taken as the first planetary gear group. The respective planetary gears 280 are installed to be rotatable and revolvable in a state of meshing with the first sun gear teeth and the inner circumference teeth gears 291 of the first ring gear while being supported by the first carrier 260 .

More specifically, the planet gears 280 are inserted into the support shaft 263 of the first carrier so as to freely rotate on the support shaft 263 of the first carrier, (Not shown) for minimizing friction when the planetary gears 280 rotate on the planetary gears 263 and 263.

The shaft of the first carrier 260 is formed as a hollow shaft 261 and a drive shaft 271 for driving the first sun gear is inserted into the hollow shaft 261. The hollow shaft 261 and the first sun gear drive shaft 271, A bearing (not shown) is inserted and rotated to be separately rotated while minimizing frictional force.

In FIG. 2, the planetary gear support shaft 263 of the first carrier is shown as being drawn out so as to more easily understand the operation of the apparatus of the present invention. However, in actual products, So that the length of the support shaft 263 is preferably as short as possible (see the cross-sectional view of FIG. 3), and the overall shape of the carrier 260 can also be varied according to the characteristics of the transmission.

Although the first sun gear 270, the planetary gears 280 of the first planetary gear group and the first ring gear 290 are shown as common planetary gears in FIG. 2, And the like.

The worm gear 240 is integrally fixed to one side of the carrier hollow shaft 261. A one-way clutch 250 having a bearing is inserted between the worm gear 240 and the carrier hollow shaft 261, (See the sectional view of FIG. 4), so that the rotational force of the speed control motor 220 is prevented from flowing back to the first sun gear side.

The worm 230 engaged with the worm gear 240 is driven by receiving power from the speed control motor 220. The rotation speed of the speed control motor 220 is controlled by a controller (TCU) 210 programmed to control according to the detected engine output, temperature, vehicle speed, and throttle opening degree.

Particularly, in the continuously-variable transmission portion 200, as described above, a separate auxiliary power such as the speed control motor is required to realize the continuously-variable shifting operation. However, the continuously variable transmission of the present invention is characterized in that it is possible to easily shift a large rotational force even with a very small rotational force.

That is, when transmitting the rotational force through gear engagement or the like, when a load is applied to the output side 450, considerable force is applied to each rotational force transmitting portion due to a reaction depending on the load. The present invention takes advantage of the fact that such force always acts on the first carrier 260 and the worm gear 240 in the direction of rotation of the first sun gear 270. Therefore, in the present invention, the worm 230 can rotate sufficiently with a very small force to rotate the worm gear 240 in the rotating direction of the first sun gear 270.

This will be described in more detail as follows.

If a load is applied to the rotating output shaft 450, the force exerted by the reaction due to the load is gradually weakened and reaches the respective power transmission parts. (For reference, in the structure of the embodiment, 290 is about 2.0857, the force applied to the planetary gear 280 of the first planetary gear group is about 1)

Since the force exerted by the reaction according to the load always acts on the worm gear 240 in the rotating direction of the worm gear 240 as described above, the speed control motor 220 can be controlled by the worm gear 240 230 can be smoothly rotated. As a result, the vehicular continuously variable transmission of the present invention can shift a large rotational force even with a very small force. For example, in the case of shifting the rotational force inputted at about 145 horsepower (HP) by the above-described method, even when a direct-current motor (DC motor) of about 180 W is used as the auxiliary power, the shift operation can be sufficiently performed, The transmission ratio can be changed finely and flexibly without affecting the transmission ratio.

In the present invention, the worm 230 and the worm gear 240 are employed in order to prevent the force acting on the reaction depending on the load from reaching the spin control motor 220, have.

In this embodiment, the force due to the reaction is intercepted using the coupling characteristics of the worm 230 and the worm gear 240. That is, in the above-described embodiment, the wedge 230 of the worm 230 is smaller than the friction angle so as to perform slef locking, so that the worm gear 240 can not rotate the worm 230.

The forward and rearward speed increasing portion 300 includes a second carrier 310 which is connected to the first ring gear shaft 293 so that the drive shaft 311 is directly connected to the first carrier gear portion 293, Second and third groups of planetary gears that rotate while being supported by gear support shafts 313 and planetary gears 320 of the second group of planetary gears, A second sun gear 330 and a second sun gear shaft 331 formed integrally with the second sun gear 330 and formed as a hollow shaft and having a second carrier drive shaft inserted therethrough, A drum 350 and a first cylinder 340 for selectively braking the drum 350 in accordance with the control of the manual valve 420.

A third sun gear 390 which is positioned at the center of the planetary gears 360 and is coupled to each of the planetary gears 360 of the third planetary gear group to receive a rotational force and is integrally coupled to the output shaft 450, The inner gear 371 is engaged with the gears of the respective planetary gears 360 of the planetary gear group so as to receive a rotational force. The rotation shaft 373 is formed as a hollow shaft and the third sun gear shaft (output shaft) A second ring gear 370 provided on the outer side of the second ring gear 370 so as to penetrate the first ring gear 370 and braking the second ring gear 370 to selectively rotate the second ring gear 370 under the control of the manual valve 420, And a second cylinder 380 are provided.

2, not only the planetary gear support shaft 313 of the second carrier is illustrated as being drawn out in a long form, but also the planetary gear support shaft 313 of the second carrier is arranged so as to be opposed to the second planetary gear group and the third planetary gear group at 120- Each of the planetary gears 320 and 360 is shown as being formed separately, which is an example only for facilitating understanding of the present invention. Preferably, the length of the planetary gear support shaft 313 is as short as possible, and each of the second planetary gear group planetary gears 320 and the third planetary gear group planetary gears 313, 360 are preferably integrally formed to form a set (see 320 and 360 in FIG. 3).

The integrally formed planetary gears are mounted on the planetary gear support shaft 313 of the second carrier 310 and are supported by bearings (not shown) to minimize friction when rotating on the support shaft 313 Sound).

A bearing (not shown) for minimizing frictional force is built in between the second sun gear hollow shaft 331 and the second carrier drive shaft 311 formed to penetrate the second carrier drive shaft 311, A bearing (not shown) for minimizing the frictional force is also incorporated in the second ring gear hollow shaft 373 having the third sun gear shaft (output shaft) passed therethrough.

In the above-described embodiment, the planetary gears of the first planetary gear group are constituted by three sets (three planetary gears) of the first planetary gears, and are disposed at intervals of 120 degrees around the first sun gear, So that the rotation direction of the first ring gear is opposite.

However, such a planetary gear arrangement angle and the number of planetary gears used are design problems and can be changed as needed. For example, when two planetary gears of the first planetary gear group are arranged at intervals of 90 degrees and two planetary gears are arranged at intervals of 90 degrees, four groups of eight planetary gears are formed, The rotation direction of the gear is matched.

In the above-described embodiment, the planetary gears of the second and third planetary gear groups are constituted by three planetary gears (three planetary gears) and are disposed at angular intervals of 120 degrees around the second and third sun gears , Which is a simplified example for simplifying the understanding of the working principle of the present invention. As in the case of the first planetary gear group, the planetary gear arrangement angle and the number of usage can be changed as needed.

Particularly, in the case of the third group of planetary gears, unlike the structure shown in FIG. 2, two planetary gears are arranged to be mutually meshed with each other, that is, three to six planetary gears, 1 ring gear and the third sun gear coincide with each other.

In the drawing, reference numeral 440 denotes a parking locker, reference numeral 430 denotes a governor, and reference numeral 410 denotes a solenoid valve. The manual valve 420 is controlled by a selection lever operation position (for example, P (parking), R (rear), N (normal), D (dirve), etc.) The oil pressure acts on the torque converter 120 and the ringer 380 and acts on the cylinder 340 in the backward operation to be controlled respectively.

Hereinafter, the operation of the continuously-variable transmission portion 200 and the forward / reverse speed increasing portion 300, which are essential portions of the present invention, will be described.

As shown in the figure, the first sun gear 270, which is integrally connected to the drive shaft 271, is directly driven to receive a rotational force, as shown in the drawing.

Then, the first ring gear 290 is rotated while the three planetary gears 280 engaged with the first sun gear 270 rotate. At this time, deceleration is performed at a constant rate according to the number of teeth of the first sun gear and the number of teeth of the first ring gear.

That is, when the first sun gear teeth number ZA is 35, the planetary gear teeth number ZS of the first planetary gear group is 19, and the first ring gear teeth number ZC is 73, Is expressed as [Equation 1].

At this time, the planetary gear can only be an idle gear that simply transmits the rotational force of the first sun gear 270 to the first ring gear 290.

For reference, in the present invention, as in this case, the planetary gear is rotated while transmitting the rotational force to the inner circumferential surface of the ring gear simply in accordance with the rotation of the sun gear, with the planetary gear engaged between the sun gear and the ring gear The phenomenon is called rotation.

On the other hand, when the planetary gear is meshed with the sun gear and the ring gear, a case in which a rotational force is transmitted to the inner circumferential surface of the ring gear while conveying a separate driving force from the outside and traveling along the outer circumferential surface of the sun gear itself, is referred to as idle .

Further, in the present invention, by controlling the speed control motor 220 by the controller (TCU) of the vehicle, stepless flexible shifting is performed in addition to the fixed decelerating operation as described above.

The speed control motor 220 can drive the worm 230 and the worm gear 240 with a small power while the fixed deceleration is performed at a constant fixed speed reduction ratio as described above. When the gear 240 is driven, the first carrier 260 is engaged with the first sun gear 270 to rotate the planetary gears 280 of the first planetary gear group in the sun gear rotating direction. At this time, the rotational force transmitted to the first ring gear 290 is flexibly shifted, and the speed ratio thereof is increased in proportion to the idle speed of the first planetary gear group planetary gears 280. In the present invention, this is referred to as a first-order continuously-variable shifting.

As described above, during the fixed deceleration and the first-order continuously variable shifting, the speed ratio is reduced (that is, the deceleration rate of the input-output rotation speed is reduced) as the rotational speed of the driving force transmitted to the input shaft 110 increases In the present invention, this is referred to as a second-degree continuously-variable transmission.

The principle of the primary and secondary continuously variable shifting will be described more easily in the following description of FIGS. 4 to 6.

The vehicle requires an appropriate torque and rotation speed from low-speed running to high-speed running depending on the running state. As mentioned above, only the shifting operation which only decelerates the rotational speed of the vehicle with respect to the engine output, The rotational speed can not be adjusted. For example, in the case of a high-speed driving, a rotational speed larger than the original rotational speed for the engine output is required. However, since the continuously-variable transmission portion 200 shown in the embodiment has the minimum speed ratio (when the planetary gear group does not revolve in the sun gear rotational direction) is about 1 / 2.0857, It can not be used, and a separate accelerator is required.

Therefore, the forward / reverse speed increasing portion 300 is provided at the rear end of the stepless speed change portion 200 so as to perform the constant speed increase with respect to the rotational force shifted by the stepless speed change portion 200, So that a true operation is performed.

Now, the operation of the forward / reverse accelerating portion 300 will be described. First, the second carrier 310 receiving the power from the first ring gear shaft 293 is rotated. Then, the second sun gear 330 and the third sun gear 390 are rotated while being rotated by the second and third planetary gears supported by the second carrier 310, respectively.

At this time, as the first cylinder 340 brakes the drum 350 so as not to rotate or the second cylinder 380 brakes the second ring gear 370, the traveling direction of the vehicle is changed do. In other words, in the case of the former, the backward operation of the vehicle is performed, and in the latter case, the forward operation of the vehicle is respectively performed.

More specifically, in the reverse operation, since the first cylinder 340 brakes the drum 350, the second sun gear 330 can not rotate, and the second carrier 330 310 rotate about the second sun gear coupled to the second group of planetary gears.

At this time, as each of the planetary gears 360 of the third planetary gear group integrally coupled to the respective planetary gears 320 of the second planetary gear group rotates together, The sun gear 390 is rotated to cause the vehicle to move backward.

In a preferred embodiment of the present invention, the gear ratio of the planetary gears 320 and the second sun gears 330 of the second planetary gear group is set to 19:35 so that the speed increase of about 1.842 times (See Equation 2).

On the other hand, in the forward operation, since the second cylinder 380 brakes the ring gear 370, the ring gear 370 can not rotate, and the second carrier 310 rotates the second and third groups of planetary gears. At this time, since the planetary gears 360 of the third group of planetary gears rotate in a state engaged with the ring gear inner circumferential surface gear 371, The third sun gear 390 engaged with each of the planetary gears 360 of the third planetary gear group rotates to advance the vehicle.

In the case of such a forward operation, in one preferred embodiment of the present invention, an acceleration of about 2.842 times is achieved (see [Expression 3]).

As a result, in the continuously variable transmission according to the embodiment, the minimum speed ratio of the continuously-variable transmission portion 200 is 2.0857 and the fixed amplification ratio of the speed increasing portion 300 is 2.842 when the speed increasing portion 300 is advanced. The gear ratio of the output shaft 450 to the gear ratio?

2, in addition to the fixed decelerating operation due to the gear ratio of the sun gear and the ring gear of the continuously-variable shifting portion 200, the planetary gear set of the continuously- The first-order continuously-variable shifting operation in which the transmission ratio is increased in proportion to the increase in the idling speed, and the second-order continuously-variable shifting operation in which the transmission ratio is decreased in proportion to the increase in the number of revolutions of the input shaft. That is, it can be said that a single step-variable shifting and a double-flexible continuously-variable shifting are combined.

Generally, when increasing the speed from low to high speed when the vehicle is running, the number of revolutions transmitted to the input shaft 110 increases in proportion to the running speed. In the vehicular continuously variable transmission of the present invention, The speed ratio is reduced in proportion to an increase in the number of revolutions of the input shaft 110 so that the speed of the vehicle is automatically increased in accordance with an increase in the number of revolutions of the input shaft even if no separate control operation is performed from the outside .

Therefore, this night vision is very suitable for a vehicle such as a vehicle that requires a large speed change ratio at a low speed but requires a reduction in the speed change ratio while increasing the speed.

4 is a conceptual diagram for explaining the operation principle of the continuously-variable transmission portion 200 of the present invention.

In order to make it easier to understand the working principle of the continuously-variable transmission portion, a system as shown in the drawings can be assumed.

(Corresponding to the worm gear of FIG. 2) and drives A (corresponding to the sun gear of FIG. 2), S (corresponding to the planetary gear of FIG. 2) To the F direction. At this time, assuming that the conveying speed is 10 m per minute and the W (worm gear) is rotated to move the S (planet gear) in the 0 direction by 2 m in 1 minute, the conveying distance of the C (ring gear) rack is 8 m .

That is, even if the A (sun gear) maintains a constant number of revolutions, if the S (planetary gear) rotates and moves, the conveying distance becomes short and the conveying force increases. In other words, a shift is performed in which the output shaft revolution speed decreases and the rotational force increases.

Consequently, according to the rotation speed of W (worm gear) for rotating S (planetary gear), the conveying distance of the C (ring gear) rack is flexibly increased or decreased. At this time, The feed distance is inversely proportional and the feed force is proportional.

When the W (worm gear) is rotated in the opposite direction, the conveyance distance of the C (ring gear) rack is proportional to the number of rotations of the W (worm gear) and the feed force is inversely proportional thereto, It requires a larger driving force. Further, when the C (ring gear) rack is moved in the F direction, a force for going out in the 0 direction is generated, so that the large feed force can be increased or decreased by a very small force.

When the drive shaft, which receives power from the main power source of the vehicle, rotates the sun gear (corresponding to A in Fig. 4), the continuously-variable transmission portion 200 of the present invention utilizing such a principle has a planetary gear (Corresponding to S of Fig. 4) is rotated, so that the rotational force is transmitted to the ring gear (corresponding to C of Fig. 4) engaged with the planetary gear. At this time, the deceleration fixed by the gear ratio of the sun gear and the ring gear is achieved.

When the planetary gear is revolved in the 0 direction by driving the worm gear (corresponding to W in Fig. 4) in order to revolve the planetary gear around the sun gear, The rotation speed of the ring gear is decreased and the torque is increased, so that a continuous primary shift is achieved.

Meanwhile, when the rotational speed of the worm gear is fixed to a constant value, that is, the planetary gear is revolved at a constant rotational speed and the sun gear rotational speed of the drive shaft is increased or decreased, .

The continuously-variable transmission portion 200 of the present invention performs the fixed deceleration and the double variable speed with the above-described principle.

5 is a conceptual diagram for explaining the continuously-variable shifting principle of the continuously-variable transmission portion 200 of FIG.

The stepless speed change principle of the continuously-variable transmission portion 200 may be explained by the concept shown in Fig.

Assuming that the number of teeth of the sun gear is set to 35, the number of teeth of the planetary gear is set to 19, and the number of teeth of the ring gear is set to 73 to drive the sun gear, the ring gear is rotated while rotating the planetary gear, .

At this time, the fixed reduction gear ratio is the same as in the above [Expression 1] .

However, when the speed control motor is driven in the course of the fixed deceleration as described above and the carrier is rotated in the sun gear rotating direction, the planetary gear rotated in the engaged state between the sun gear and the ring gear is rotated in the sun gear rotating direction Performs orbital motion in inertial space.

In this way, the planetary gear rotates and revolves in the course of mediating the transmission of rotational force. At this time, the planetary gear transmits the rotational force to the ring gear while the planetary gear moves in space, thereby shifting.

That is, in a state where the carrier is stopped, a rotational force is transmitted by one engagement ring and one engagement ring. However, when the planetary gear rotates and revolves in the inertial space and performs spatial movement, the space corresponding to the base length of the diagonal triangle shown in the drawing is shifted by the distance that the planetary gear has moved to the space, In principle, the rotational force decreases while the rotational speed decreases.

In order to more easily understand the shifting principle, FIG. 4 shows a change in the case where the planetary gear revolution increases by one rotation for a predetermined period of time. In this case, the circumferential length of the ring gear 5) is gradually increasing in a spiral shape to express a change due to the shift.

In conclusion, as the space travel distance increases with the increase of the number of revolutions of the planetary gear, the circumferential length of the ring gear becomes longer and the gear ratio increases. On the other hand, when the space travel distance becomes shorter as the number of revolutions decreases, The transmission ratio decreases.

For example, in the case shown in the drawing, the first speed-change operation is performed in which the rotational speed is further reduced by 1.497 rpm and the speed ratio is increased each time the idling speed is increased by one revolution.

6A to 6C are schematic views for explaining a shifting operation of the continuously-variable transmission portion 200 of FIG.

6A is an explanatory diagram of an operation in which the rotational speed of the ring gear is fixed and decelerated at 47.945 rpm when the input shaft sun gear revolution is 100 rpm and the planetary gear revolution water is 0 rpm.

6B is a diagram for explaining the first-order continuously-variable shifting operation. When the input shaft sun gear revolution speed is 100 rpm and the planetary gear revolution speed is 10 rpm, the ring gear revolution speed is shifted to 33.151 rpm, And it explains the reduction.

Fig. 6C is an explanatory diagram for explaining the second-order continuously-variable shifting operation. The input shaft sun gear speed is 101 rpm, which is 1% higher than that in Fig. 6B. rpm, the speed of the ring gear is shifted to 33.630 rpm to increase the speed ratio rather than the case of Fig. 6A, but the speed increase (the speed ratio is reduced) rather than the case of Fig. 6B.

[First-Aid Variable Speed]

Referring to the first-order stepless speed change, ego, When the input shaft sun gear rotational speed is 100 rpm and the revolution speeds of the planetary gears are 10 rpm or 11 rpm, respectively, the respective gear ratio is expressed by the following [Equation 5] and [Equation 6].

From the above calculation results, it can be seen that, under the above conditions, when the revolution of the planetary gear increases by one rotation, it is decreased by about 1.479 rpm, and the shifting is performed in which the speed ratio is increased. In obtaining the speed ratio, It can be seen that the number of revolutions is considered.

[Second Variable Speed]

Now, with reference to the second-order continuously variable transmission, if the input shaft rotation, that is, the sun gear revolution, is increased from 100 rpm to 101 rpm under the condition of [Expression 75 and 6] And [Equation 8], it is confirmed that the second-order stepless speed-change motion is performed separately from the first-order stepless speed-change motion.

That is, in contrast to Equations 5 and 7 and comparing Equations 6 and 8, when the sun gear speed increases from 100 rpm to 101 rpm under the above conditions, As the space travel distance becomes shorter, the circumferential length of the ring gear is shortened, and the output shaft rpm increases by about 0.479 rpm and the speed ratio is decreased.

Therefore, in order to determine the gear ratio at a certain point, it is understood that the rotational speed of the input shaft (sun gear) and the planetary gear revolution number should be considered. In particular, the continuously-variable transmission portion 200 as described above is characterized in that the speed ratio of the input shaft (sun gear) is continuously changed when the rotational speed of the input shaft (sun gear) is different from the rotational speed of the planetary gear. That is, even if the number of rotations of the input shaft (sun gear) and the number of planetary gear rotations are changed at the same ratio, the speed ratio does not keep a fixed value but continuously changes.

The results of sampling at predetermined intervals in the continuously shifting operation of the continuously variable transmission according to the embodiment of the present invention as described above are shown in Table 1 below.

In Table 1, the primary speed ratio is the speed ratio of the continuously-variable transmission portion 200, and the final speed ratio is the speed ratio between the input shaft 110 and the output shaft 450. The content of the remarks is a finite stage , 2, 3, 4, 5), and reference is made so that the present invention can be duplicated.

[Table 1]

7 is a comparative graph showing operational characteristics of the continuously variable transmission for a vehicle according to the present invention and the conventional continuously variable transmission.

Referring to the graphs shown in the drawings, the vehicular stepless speed changer of the present invention provides an optimum transmission ratio for driving conditions such as road conditions and engine output from a low-speed start to a high-speed running, To about 20% of the fuel can be saved, and it can be easily seen that the engine output can be improved by about 5 to 7%.

In the field of electronics and software, it is well known as a general technique to program to output electronic control signals according to predetermined conditions.

Therefore, a small auxiliary power for driving the first carrier of the endless decelerator 200 as desired according to the driving environment of the vehicle, and a vehicle engine output for driving the first sun gear are controlled by software It is clear that you can do it. That is, a preferable transmission ratio for each case can be predicted in advance for all cases predicted at the time of traveling of the vehicle, and a control program is built in the controller (TCU) of the vehicle so as to be shifted according to the result, .

Therefore, in the case of the vehicle using the vehicular continuously variable transmission, the input signals varying from time to time during traveling are received from the controller (TCU), the optimal transmission ratio is calculated using the built-in control software, By appropriately controlling the revolution speed per minute of the speed control motor 220 of the electric power steering apparatus 200, it is possible to achieve the optimum efficiency in terms of power use efficiency.

Further, according to the present invention described above, it is possible to easily provide a suitable speed change ratio for various environments, and to be software-controllable, it is possible to provide a shift control device capable of coping with any environment change that can be foreseen during a start- A control algorithm is preliminarily programmed so that a predetermined control device manages the control algorithm, and even the driving operation can be unmanned in a tracked vehicle or the like.

Another feature of the vehicular continuously variable transmission device according to the present invention is that it can be applied to general purpose regardless of a manufacturer of a vehicle or the like.

In the case of automobiles, the reduction ratio of each stage (1, 2, 3, 4, and 5 stages) of the transmission is different from each other due to a problem caused by different engine output characteristics and unique design for each production company. Accordingly, until now, the transmission devices have been separately designed and manufactured for each manufacturer. According to the present invention, it is possible to provide a suitable transmission ratio for all specifications only by changing the software of the control device mounted on various vehicles.

The above-described continuously variable transmission of the present invention can be applied to all the devices requiring the use of the power generated by the main power source in accordance with the situation, and it is also possible to use, for example, , Ships, and aircraft.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention by way of illustration only and it is not intended to limit the scope of the invention. It will be apparent to those skilled in the art that various substitutions, modifications, and changes can be made thereto without departing from the scope of the present invention.

According to the present invention as described above, it is not necessary to accelerate the vehicle at the time of shifting from various vehicles to the high-speed gear, and it is always necessary to set the optimum gear ratio considering the state of the load, So that the engine output can be improved and fuel consumption can be reduced.

In addition, the effects such as reduction of exhaust gas, noise reduction, improvement of convenience of vehicle operation, etc. are very great, and since the structure is made simple with remarkably enhanced reliability as power transmission by gear engagement, .

Claims (14)

1. A vehicular stepless transmission device for steplessly and continuously changing a rotational force generated by a power generating means of a vehicle, A first sun gear that is driven to receive a rotational force generated by the power generating means, a first ring gear that is driven to receive a rotational force from the first sun gear, and a second sun gear that is engaged with the first sun gear and the first ring gear A fixed deceleration means for decelerating a rotational speed of the power generated by the power generating means by a predetermined ratio, the first and second planetary gears being provided with a first planetary gear group that mediates power transmission; Continuously variable transmission means for flexibly shifting the rotational force output to said first ring gear by revolving said first planetary gear group in the same direction as the rotational direction of said first sun gear; And A forward / reverse speed increasing means for increasing / decreasing the rotational force output from the first ring gear and switching the rotational direction of the output shaft in accordance with forward / And a control unit for controlling the continuously variable transmission. The method according to claim 1, The first group of planetary gears, And at least two planetary gears meshed between said sun gear and said ring gear installed coaxially and mediating power transmission. 3. The method of claim 2, The first group of planetary gears, And three planetary gears disposed at angular intervals of substantially 120 degrees about the first sun gear. 3. The method of claim 2, The first group of planetary gears, And three to six planetary gears disposed at angular intervals of substantially 120 degrees about the first sun gear. 3. The method of claim 2, The first group of planetary gears, And four planetary gears disposed at angular intervals of substantially 90 degrees around the first sun gear. The method according to claim 1, Wherein the continuously- Auxiliary power supply means capable of controlling the output rotational speed; A worm that receives power from the auxiliary power providing means and rotates; A first carrier which is integrally formed with the hollow shaft and is fitted on the first sun gear shaft and supports the first planetary gear group so as to revolve; A worm gear which is disposed on one side of the hollow shaft of the first carrier and fitted to the worm so as to receive power from the worm and rotate the first carrier; And A power transmission interrupting means for interrupting power transmission by temporarily releasing engagement between the first carrier hollow shaft and the worm gear in order to prevent the rotational force of the auxiliary power providing means from flowing back to the first sun gear side, And a control unit for controlling the continuously variable transmission. The method according to claim 6, Wherein the auxiliary power providing means comprises: And a speed control motor capable of controlling a rotational speed that is electronically output. The method according to claim 6, Characterized in that the worm forms a twist angle at a predetermined angle so as to self-lock so as not to be rotated by a force applied from the worm gear. The method according to claim 6, The power transmission interrupting means includes: And a one-way clutch interposed between the worm gear and the first carrier shaft. 7. The method according to claim 1 or 6, Wherein the forward / A second carrier rotatably connected to the first ring gear shaft via a driving shaft; A second and a third group of planetary gears rotated while being respectively supported by the planetary gear support shafts of the second carrier; A second sun gear positioned at a center of the planetary gears of the second group of planetary gears so as to receive rotational force; A drum integrally formed with the second sun gear and integrally coupled to the other end of a second sun gear shaft which is formed as a hollow shaft and through which the second carrier drive shaft penetrates; A first cylinder (340) selectively braking the drum to prevent it from rotating; A third sun gear fixed to the planetary gears of the third planetary gear group and integrally coupled to the output shaft, The third sun gear shaft is coupled to the inside of the third sun gear shaft so as to penetrate therethrough, and the second sun gear shaft is installed on the outer side of the first sun gear shaft, A second ring gear on which a drum is formed; And And a second cylinder for selectively braking the second ring gear to prevent the second ring gear from rotating. 11. The method of claim 10, Wherein the forward / When the first cylinder brakes the drum and the second sun gear can not rotate, the second carrier rotates the second and third groups of planetary gears, and the third group of planetary gears The engaged third sun gear rotates, causing the vehicle to reverse, When the second cylinder brakes the ring gear and the second ring gear can not rotate, the second carrier rotates the second and third groups of planetary gears to rotate the third planetary gear group The planetary gears rotate in engagement with the inner ring gear of the second ring gear, and the third sun gear rotates to advance the vehicle. 11. The method of claim 10, The third group of planetary gears, And three planetary gears disposed at angular intervals of substantially 120 degrees about the third sun gear. 11. The method of claim 10, The third group of planetary gears, And three to six planetary gears disposed at angular intervals of substantially 120 degrees about the third sun gear. 11. The method of claim 10, A bearing is built in each of the first carrier hollow shaft, the second sun gear hollow shaft, and the second ring gear hollow shaft so as to minimize friction upon rotation, Characterized in that a bearing is built in between each of the planetary gears of the first to third planetary gears and the first and second carrier support shafts to minimize friction during rotation.