KR19990073062A - continuous transmission for a car - Google Patents

Abstract

The present invention discloses a continuously variable automatic transmission for a vehicle having a novel configuration.

A continuously variable automatic transmission for a vehicle according to the present invention includes a ring gear and a sun gear arranged coaxially with each other, and a vehicle transmission having a plurality of planetary gears connected by a carrier to connect the ring gear and the sun gear.

One of the planetary gear carrier or the ring gear and the sun gear is connected to the first input shaft on the engine side, the other is connected to the output shaft on the wheel side, the other is connected to the second input shaft, and is connected to the second input shaft A governing means for controlling the rotational speed is provided.

According to this configuration, not only the continuous shift is made according to the rotational speed of the engine, but also the arbitrary shifting is possible at any engine rotational speed by adjusting the rotational speed of the governing motor.

Accordingly, the present invention has the effect of providing a continuously variable automatic transmission with a simple structure and low cost to achieve the optimum driving state at a low fuel consumption rate is made automatically by the gear transmission.

Description

Continuous Transmission for Cars {continuous transmission for a car}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a continuously variable transmission of an automobile, and more particularly to a continuously variable automatic transmission that can be configured in a geared electric system.

Power trains that transfer power from the engine to the wheels include components such as clutches, transmissions, propeller shafts, final reduction gears, differentials, and axle shafts. do. Among these, the transmission is a device for switching forward and backward of the vehicle and transmitting an appropriate torque in accordance with the driving condition of the vehicle due to road conditions.

In general, the transmission is divided into manual and automatic. In general, the automatic transmission uses a fluid converter to automate the operation of the clutch and the transmission to facilitate operation, absorb vibration and shock, and reduce engine overload. There are a number of benefits to avoid.

Most of the automatic transmissions currently used use planetary gear devices as shown in FIG. 1. First, the configuration and operation principle thereof will be described. In Fig. 1, the planetary gear device coaxially installs a sun gear S inside a ring gear R, and mutually carriers between the ring gear R and the sun gear S. It is configured by being bitten by a plurality of planetary gears (P) connected by (carrier; K1, K2).

The planetary gear device is provided between the drive shaft D from the fluid converter on the engine side and the output shaft O to the wheel side, and the drive side carrier K1 of the planetary gear P is the output side carrier on the drive shaft D side. K2 is intermittently connected to the output shaft O, and the ring gear R and the sun gear S are also intermittently connected to the drive shaft I side to rotate and brake if necessary. It can be fixed by; B).

Here, the planetary gear P rotates around the sun gear S along the inner circumference of the ring gear R while rotating as shown in FIG. Power is transmitted between the sun gear (S). Therefore, the reduction ratio in the planetary gear system is determined by the gear ratio between the sun gear (S) and the ring gear (R). For example, the gear ratio of the sun gear (S) and the ring gear (R) is 20: When 80, 1: 4, the planetary gear is operated as shown in Table 1 below.

TABLE 1

In this way, the planetary gear unit is directly connected, decelerated, accelerated, reversed, and driven by freely combining three elements of the sun gear S, the ring gear R, and the drive side carrier K1 of the planetary gear P. A neutral shift state can be obtained.

However, in such a planetary gear device, the speed ratio that can be formed by the combination of the three elements is fixed to a certain number, and the speed ratio is suitable for the required speed ratios such as 1 to 4 speed, neutral and reverse in the actual vehicle. I can't.

Accordingly, in order to realize the actual transmission ratio, an automatic transmission is constructed by combining two or more planetary gear devices (generally two) before and after the same as in FIG. 1, in which case the two planetary gear devices have the same configuration or It has a structure sharing the ring gear (R) or sun gear (S) with each other.

In the conventional automatic transmission, the planetary gear device constituting the transmission is connected to the drive shaft D along the ring gear R, the sun gear S, and the planetary gear P (drive side carrier K1 of the planetary gear P), respectively. The operation is very complicated and the operation is complicated because the operation to drive (unlock) and release (free) and fix the rotation is necessary. This problem is further aggravated by using two or more planetary gear units because the required gear ratio cannot be obtained with a single planetary gear unit.

In addition, at the time of the shift operation, at least one of each of the rotating components must be selectively increased or decreased, and in this case, the torque transmitted to each of the components changes rapidly, so that the load can be reduced and the shock can be alleviated. Conventional automatic transmissions are forced to use a fluid transmission method through a fluid converter, the structure is more complicated and the transmission efficiency is bound to be lowered.

This not only increases the price of the automatic transmission, but also increases the weight of the vehicle and increases the loss of power transmission, leading to a significant increase in fuel consumption (generally more than 10% over manual vehicles). In addition, the complex structure frequently causes a breakdown, which greatly increases the maintenance cost of the vehicle.

Nevertheless, the speed ratio obtained in the conventional automatic transmission is only a few steps, and thus the optimum shift according to the driving state of the vehicle is not possible.

Accordingly, researches on continuously variable transmissions are being conducted. This is to realize an optimum transmission ratio according to the driving condition of the vehicle and to improve the driving performance of the vehicle and to reduce fuel consumption rate, but it is still satisfactory for practical use. The continuously variable transmission of construction is not appearing.

The present invention solves such a conventional problem, it is possible to use a very simple structure and operation is practical, and can be configured by direct transmission method such as gear transmission method, rather than indirect transmission method such as fluid transmission method, high efficiency An object of the present invention is to provide a continuously automatic transmission.

1 is a perspective view illustrating main parts of a conventional automatic transmission for a vehicle;

2 is a gear arrangement diagram for explaining the operation of the automatic transmission of FIG.

Figure 3 is a perspective view showing the main portion of the continuously variable automatic transmission according to the present invention,

Figure 4 is a gear arrangement diagram illustrating the operation of the transmission of the present invention of Figure 3,

5 is a graph showing the shift relationship of the present invention with respect to Vp,

5 is a graph showing the transmission relationship of the transmission of the present invention with respect to the transmission.

<Description of the code used in the main part of the drawing>

P: planetary gear

R: ring gear

S: sun gear

K: Carrier

I1, I2: first and second input shaft

O: output shaft

V: governing means

T: One-sided electric means

M: governing motor

I3: governing shaft

F: freewheel

W: worm gear

P: wheel gear

In order to achieve the above object, the continuously variable automatic transmission for a vehicle according to the present invention includes:

A vehicle transmission comprising a ring gear and a sun gear arranged coaxially with each other, and a plurality of planetary gears connected by a carrier to connect the ring gear and the sun gear,

One of the planetary gear carrier or the ring gear and the sun gear is connected to the first input shaft on the engine side, the other is connected to the output shaft on the wheel side, and the other is connected to the second input shaft,

A governing means connected to the second input shaft for controlling the rotational speed thereof is provided.

According to one preferred feature of the invention, the carrier of the planetary gear is connected to the first input shaft on the engine side, the ring gear is connected to the output shaft on the wheel side, and the sun gear is connected to the second input shaft.

According to another preferred feature of the present invention, the speed governing means has a speed motor capable of changing its rotational speed and a one-way transmission means so that its maximum rotational speed is not generated by a gear connected to the second input shaft. According to another preferred feature of the invention, the maximum rotational speed of the gear connected to the second input shaft is controlled to be less than the rotational speed of the governing motor.

According to such a configuration, not only the continuous shift is made according to the rotational speed of the engine, but also the arbitrary shifting is possible at any engine rotational speed by adjusting the rotational speed of the governing motor, so that the automatic continuously variable shifting is achieved only by the gear connection. You lose.

Accordingly, the present invention has the effect of providing an continuously variable automatic transmission capable of realizing an optimal driving state with a low fuel consumption rate as the output of the vehicle is not only continuously shifted but also by direct transmission.

Example

Such specific features and advantages of the continuously variable transmission of the present invention will become more apparent from the following description of the preferred embodiment with reference to the accompanying drawings.

In Fig. 3, the continuously variable transmission of the present invention is connected to a ring gear (R) and a sun gear (S) coaxially arranged like a planetary gear device of a conventional automatic transmission, and is connected by a carrier (K) to the ring gear (R) and the sun gear. The some planetary gear P which connects between (S) is provided.

According to a feature of the invention, any one of the carrier K and the ring gear R and the sun gear S of the planetary gear P (in this embodiment, the carrier K) is connected to the first input shaft I1, and One (sun gear S in this embodiment) is connected to the second input shaft I2, and the other (ring gear R in this embodiment) is connected to the output shaft O.

That is, the continuously variable automatic transmission of the present invention includes two input shafts I1 and I2 and one output shaft O. The first input shaft I1 is connected to the engine side and driven as in the conventional driving shaft (D of FIG. 1). The second input shaft I2 is connected to and driven by the governing means V, and the output shaft O is connected to the wheel side as in the prior art to drive the same.

The speed governing means V for controlling the rotation of the sun gear S through the second input shaft I2 is preferably

Gross speed motor (M) and one-way transmission means (T) is provided, first, the speed motor (M) is a rotation that can vary the rotational speed and the torque accordingly (torque) It consists of a drive means, preferably an electric motor which uses the power source of the vehicle as a power source.

On the other hand, the one transmission means (T) can be used in a variety of configurations, in the embodiment of Figure 3, the one transmission means (T), the freewheel (freewheel) between the governing shaft (I3) and the second input shaft (12) and a worm gear (W) and a wheel gear (P) between the governing shaft (I3) and the governing motor (M).

The freewheel (W) allows transmission from the second input shaft (I2) to the governing shaft (I3) but blocks transmission on the opposite side to prevent transmission from the governing motor (M) to the sun gear (S). On the other hand, the worm and the wheel gears (W, P) are characterized in that the rotation of the worm gear (W) is transmitted to the wheel gear (P), but the rotation of the wheel gear (P) is not transmitted to the worm gear (W), so The rotational force is not transmitted to the governing motor (M) side.

During driving of the vehicle, the governing motor M and the sun gear S rotate as described below. The rotational force of the governing motor M and the rotational force of the sun gear S are provided according to the provision of the one-way transmission means T as described above. Are transmitted only up to the speed axis I3, respectively. First, when the rotational speed of the sun gear S is slower than the rotational speed of the governing motor M, the freewheel F is idle, so the sun gear S maintains its own rotational speed without changing the rotational speed. As a result, the governing motor M is not loaded by the sun gear S. On the other hand, when the sun gear S wants to rotate faster than the speed of the speed motor M, the excess rotational force of the sun gear S transmitted to the speed governing shaft I3 is between the wheel gear P and the worm gear W. Therefore, the sun gear S connected to the governing shaft I3 through the freewheel F is forced to rotate at the same rotational speed as the governing motor M. As a result, the reverse speed due to the sun gear S is not applied to the governing motor M. As shown in FIG.

Thus, the governing means (V) of the present invention allows the free rotation of the sun gear (S) while controlling the maximum rotational speed does not exceed the rotational speed of the governing motor (M) (that is -∞ <Vs ≤ Vm Where Vs is the rotational speed of the sun gear (S) and Vm is the rotational speed of the governing motor (M).) As a result, the engine rpm is increased by depressing the accelerator pedal so that the rotational speed of the sun gear (S) is the speeding motor (M). When the rotational speed of the vehicle is to be exceeded, the increase of the rotational speed is suppressed, and the suppressed rotational force is transmitted to the ring gear R, thereby increasing the speed ratio and accelerating the vehicle. This process also serves to protect the governing motor (M) by preventing the reverse load or reverse electromotive force generated in the governing motor (M).

At this time, the rotational force of the speeding motor (M) and the rotational force of the sun gear (S) is transmitted only to the speeding shaft (I3), respectively, so that the load (負荷) on the speeding motor (M) is the speeding shaft through the worm and the wheel gear (W, P). Only the torque required to maintain the rotation of (I3), but the acceleration shaft (I3) during the acceleration of the vehicle is rotated by the torque of the sun gear (S) driven from the engine, so the required torque of the governing motor (M) or Energy consumption is very small.

In addition, instead of forming a gear on the outer circumference of the ring gear (R) and connecting it to the output shaft (O) side, it is also possible to use a structure that connects between the ring gear (R) and the output shaft (O) by a carrier, shown separately Although not, the rear end of the output shaft (O), there may be further provided with an appropriate reverse gear device and the inertia control device between the wheel.

Such a continuously variable automatic transmission of the present invention uses a planetary gear device similar to the planetary gear device of the conventional automatic transmission, but the transmission method is made of a direct gear transmission method, not a fluid transmission method, and the two input shafts I1 and I2. The operation of the output shaft O and the provision of the governing motor M are also completely different. This will be described with reference to FIG. 4.

In Fig. 4, the planetary gear P connected to the first input shaft I1, which is the drive shaft D from the engine, is formed of the sun gear S at the inner circumference of the ring gear R according to the driving of the first input shaft I1. While rotating around, the rotation between the sun gear S and the ring gear R is caused to rotate.

Assume that the gear ratios P: S: R: = Zp: Zs: Zr of each gear, and the rotational speed (speed) of each gear are Vp, Vs, Vr. However, the rotation speed of the planetary gear (P)

The rotation speed of the carrier K, not the rotation speed of the sun gear S and the ring gear R, is meant. Then, the following relational expression (1) is obtained in the relation of the rotational speed of the planetary gear device consisting of three gears (P, S, R).

Vr =-(Zs / Zr) × Vs + (1 + Zs / Zr) × Vp .......... (1)

Here, the positive sign indicates that the planetary gear P and the ring gear R rotate in the same direction, and the negative sign means that the sun gear S rotates in the opposite direction.

As described above, the carrier K of the planetary gear P is connected to the first input shaft I1 from the engine, the ring gear R is connected to the output shaft O toward the wheel side, and the sun gear S is It is connected to the 2nd input shaft I2 from the speed governing motor M. As shown in FIG. It should be noted that each gear (P, S, R) connected to the three axes (I1, I2, 0) has a minimum work or energy of the whole system according to the principle of minimum work. It works.

That is, when the engine starts to run and idling, the planetary gear P connected to the engine via the first input shaft I1 revolves at the speed of this idling speed Vp. The planetary gear P is then connected to the outer ring gear R and the inner sun gear S, respectively, so that at least one of them is transmitted. However, since the load of the wheel is applied to the ring gear R through the output shaft O, if less energy is required to rotate the sun gear S, the sun gear S rotates while the ring gear R is stopped. To do

It becomes a state. This condition is as mentioned later.

Then, since Vr becomes 0, in the formula (1), the sun gear S and the second input shaft I2 rotate at a speed of Vs = (1 + Zs / Zr) / (Zs / Zr) × Vp. The torque is not transmitted to the ring gear R and the output shaft O, so that the engine maintains idling.

For example, if the gear ratio (Zp: Zs: Zr) of the three gears (P, S, R) is 1: 2: 4, equation (1) shows Vr = -0.5 × Vs + 1.5 × Vp ... If the idle speed of the engine, i.e., the revolution speed of the first input shaft I1 and the planetary gear P is 800 rpm, the sun gear S is represented by Equation (1). Is rotated at 2400 rpm in the opposite direction, and the ring gear R is stopped (Vr = 0).

In this state, the governing motor M is set to a speed slightly higher than the sun gear S, for example, 2700 rpm, in consideration of the variation in the rotational speed during engine idle, thereby maintaining rotation. In this state, when the engine becomes 900 rpm or more by pressing the accelerator pedal, the sun gear S attempts to rotate at 2700 rpm or more to maintain the output of the ring gear R, but the sun gear S is driven by the speed control unit V. Since the rotation speed of the governing motor (M) can not be rotated faster, the sun gear (S) is to maintain the rotation at the same speed as the rotational speed of the governing motor (M) 2700rpm. The suppressed rotational force then begins to be transmitted to the ring gear R so that the vehicle starts moving forward.

That is, the neutral state in the continuously variable automatic transmission of the present invention is made under the condition that the rotation speed of the sun gear S due to the rotation of the engine is less than or equal to the rotation speed of the governing motor M, and the engine accelerates to the sun gear S. If the rotational speed of the motor is greater than the rotational speed of the governing motor (M), the rotational speed of the sun gear (S) is suppressed by the governing means (V) while the electric power is started to the ring gear (R) and the vehicle starts to start. .

At the start of such a vehicle, since the transmission ratio is almost zero, the maximum torque is transmitted to the wheels so that the vehicle starts smoothly and the engine is not given an excessive load so that starting is maintained.

In this state, if the accelerator pedal is further depressed, the engine rpm, ie, the idle rpm of the planetary gear P, is further increased, and the ring gear R is continuously shifted to the shift state according to the equation (1) to maintain rotation. In the above example, if the engine, that is, the planetary gear P rotates at 1800 rpm as shown in Figs. 5 and 6 according to equation (1 '), the rotation speed of the ring gear (R) becomes 1350 rpm and is 0.75. If the planetary gear (P) is 270Orpm, the ring gear (R) is 2700rpm, and if the planetary gear (P) is 360Orpm, the ring gear (R) is 4050rpm (1.125) Implement the speed ratio. At this time, the rotational speed of the sun gear (S) becomes the rotational speed set in the governing motor (M) acts as a constant in the formula (1 ').

Here, the rotational speed Vr of the ring gear R is linearly increased in accordance with the rotational speed Vp of the planetary gear P, as shown in FIG. 5, and the transmission ratio thereof is shown in FIG. 6. As shown in the figure, the speed of the transmission of the present invention is continuously increased.

Such a speed ratio is for a state in which the rotational speed Vm of the governing motor M is set to a predetermined rotational speed, for example, 2700 rpm, depending on the change of the rotational speed Vm of the governing motor M. Any speed ratio and torque can be implemented at the engine speed of. For example, if you are driving at 3600rpm and want to increase the speed ratio above the set value (1.125), that is, if you want so-called over-drive, the rotation speed of the governing motor M is reduced to, for example, 1800rpm. Then, the rotation speed of the ring gear (R) is increased to 450Orpm in Equation (1 ') to achieve a high speed ratio of 1.25. 5 and 6 show a dotted line on the upper side of the reference shift line indicated by a solid line. The upper dotted line shows the shift relationship of the overdrive state when the rotation speed of the governing motor M is maintained at 1800 rpm. .

On the other hand, in the case of driving to meet the ramp while reducing the speed ratio, that is, to increase the torque, on the contrary, the rotation speed of the speed motor M is increased to, for example, 3600 rpm. Then, the rotation speed of the ring gear R is reduced to 3600 rpm in Equation (1 '), and the transmission ratio of 1.125 is reduced to 1.0, thereby increasing the torque. This is indicated by a dotted line below the reference transmission line indicated by solid lines in Figs. As shown, the lower dotted line shows the shift relationship of the high torque state when the rotational speed of the governing motor M is maintained at 360Orpm.

As described above, the continuously variable automatic transmission according to the present invention changes the ratio of the rotational speeds of two gears among the three gears of the planetary gear device by changing the rotational speed of the governing motor M so that the output of the transmission ratio according to this ratio is applied to the other gear. This allows transmission to achieve arbitrary speed ratios for all rotational speeds of the engine. Accordingly, it is possible to achieve an ideal shift for a specific vehicle according to the determination of the diameter of the three gears or the gear ratio.

Therefore, the continuously variable automatic transmission of the present invention always delivers the optimum torque according to the driving state of the vehicle, thereby maintaining the optimum driving state and optimizing the fuel consumption rate.

As described above, the continuously variable automatic transmission of the present invention is continuously variable, that is, there is no sudden change in torque during shifting, and thus, even when the transmission is made by using a mechanical transmission method instead of a fluid transmission method, it is not a fluid transmission method. Will not occur.

On the other hand, in the present invention, the governing motor (M) composed of an electric motor, etc. to maintain the constant rotation while the vehicle is running, the one-way transmission means (T) of the governing means (V) the governing motor (M) to its own rotation. In addition to the required load, it is always rotated under no load, and the energy consumption is very small. Accordingly, the present invention provides a fluid converter

Compared with the conventional automatic transmission in which the hydraulic source must be driven at all times for driving, a large reduction in fuel consumption is possible.

Therefore, the present invention provides a continuously variable automatic transmission with a simple structure and a low manufacturing cost, which can realize an optimal driving state at a low fuel consumption rate.

Claims (4)

In a vehicle transmission having a ring gear and a sun gear arranged coaxially with each other, and a planetary gear connected to the carrier to connect the ring gear and the sun gear connected, One of the carrier or ring gear and sun gear of the planetary gear is connected to the first input shaft on the engine side, another is connected to the output shaft on the wheel side, and the other is connected to the second input shaft, Is provided with a governing means connected to the second input shaft to control the rotational speed A continuously variable automatic transmission for a vehicle. The method of claim 1, A carrier of the planetary gear is connected to a first input shaft on the engine side, The ring gear is connected to the output shaft on the wheel side, The sun gear is connected to the second input shaft on the A continuously variable automatic transmission for a vehicle. The method of claim 1, wherein the governing means, A governing motor capable of changing its rotation speed, It is provided with a one-way transmission means for blocking the transmission of the rotational force between the second input shaft and the speed motor. A continuously variable automatic transmission for a vehicle. The method according to any one of claims 1 to 3, The rotation speed of the gear connected to the second input shaft among the carrier or ring gear and the sun gear of the planetary gear is controlled to be less than the rotation speed of the governing motor by the one-way transmission means. A continuously variable automatic transmission for a vehicle.