JPS5821141B2 - automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to automatic transmissions, and more particularly to an incremental step structure.

Automatic transmissions usually use a torque converter to increase the torque output from the engine, but this increase in torque alone does not provide the driving force that satisfies all driving conditions. It is also common to use a planetary gear type transmission mechanism in conjunction with the vehicle so that it can also travel backwards.

The planetary gear transmission mechanism is controlled by the combination of various friction elements and the activation and deactivation of one-way clutches, and each gear stage that determines the rate of increase in torque can be selected according to this control. The vehicle can be run with the appropriate shaft torque.

By the way, this type of automatic transmission is normally set to three forward speeds and one reverse speed, but when increasing the number of speeds, conventionally it was natural to increase the number of planetary gear sets. However, due to the increase in the number of friction elements and one-way clutches, it has been common practice to completely change the design of the planetary gear type transmission mechanism to cope with this problem.

However, if the overall design of the planetary gear type transmission mechanism is changed about nine times in this way, not only will the work be frequent and troublesome, but the cost of the planetary gear type transmission mechanism will increase significantly. It would be difficult to apply it to inexpensive vehicles, as it would involve a significant increase in weight.

The present invention eliminates the above-mentioned disadvantages and is relatively inexpensive by separately setting these two gears on the input side of the planetary gear type transmission mechanism, that is, on the torque converter side, and making it possible to use these gears selectively. Moreover, from the viewpoint of easily increasing the number of gears of the automatic transmission, we propose an automatic transmission that embodies this idea.

Hereinafter, the present invention will be described in detail based on the specific embodiments shown in the drawings.

FIG. 1 shows only the main parts of the automatic transmission of the present invention, in which 1 is a torque converter, 2 to 4 are a pump impeller, a turbine runner, and a stator impeller, respectively, and the whole is covered by a converter housing 5.
A transmission case 6 containing a planetary gear type transmission mechanism (not shown) is attached to the rear of the transmission case 6.

Between the converter housing 5 and the transmission case 6, a pump housing 8 and a pump cover 9 of a gear pump 7, which functions as an oil pump for an automatic transmission, are installed (in a combined state).
An outer gear 10 and an inner gear 11, which are the main components of the gear pump 7, are enclosed between the pump housing and the pump cover.

The pump impeller 2 of the torque converter 1 is connected to the input shaft (engine crankshaft) through the converter cover 12.
The pump impeller 2 is further spline-coupled to the inner gear 11 of the gear pump 7 via a hollow pump drive shaft 14 so that the gear pump 7 is driven by the engine. possible.

The stator impeller 4 is rotatably mounted only in the engine drive direction via a one-way clutch 16 on a hollow fixed shaft 15 having a pump cover 9 integrally provided thereon.

In the present invention, a planetary gear set 17 is provided close to the turbine runner 3 of the torque converter 1, and its internal gear 18 is connected to the turbine runner 3 through the rivet 19.
and the sun gear 20 is mounted on the hollow fixed shaft 15 via the one-way clutch 21.

One-way clutch 21 functions similarly to one-way clutch 16, and supports sun gear 20 on hollow fixed shaft 15 so as to be rotatable only in the engine drive direction.

Internal gear 18 and sun gear 2 of planetary gear set 17
The carrier 24 supported on the shaft 23 (spline-coupled to the torque converter output shaft 25) and the lock-up clutch piston 26 (spline-coupled to the shaft 23) on the other hand Join.

That is, the outer peripheral edge of the carrier 24 is the drive plate 27.
Attach the rivet 28 to the drive plate 27.
An annular plate 29 is provided opposite to the outer peripheral edge of.

The outer peripheral edge of the drive plate 27 and the annular plate 29 are connected to the second
As shown in the drawings and FIG. 3, the rivets 30+ are joined at regular intervals, and a plurality of rectangular openings 31 facing each other are formed in both, preferably symmetrically arranged at equal intervals in the circumferential direction.

The coil springs 32 are fitted into the rectangular openings 31 facing directly opposite each other to hold the coil springs 32 in a compressed state between the outer peripheral edge of the drive plate 27 and the annular plate 29.

The outer peripheral edge of the drive plate 27 and the annular plate
This rectangular notch 33 is opened at both ends of the rectangular opening 31 and faces each other.

The lock-up clutch piston 26 is shown in FIG.
As shown in the figure, the inner peripheral edge is slidably fitted to the carrier 24 under a liquid-tight seal with the O-ring 34, and the outer peripheral edge is bent and a notch is provided in it to form a comb shape. The protrusion 35 is set.

The distance between the opposing side lines of adjacent pairs of these projections 35 is clearly shown in FIGS. 2 and 3, and the rectangular opening 3
By making each protrusion 35 penetrate into the corresponding rectangular notch 33, the drive plate 27, and therefore the carrier 24, can be locked into the clutch piston 26 via the torsional damper 36 made up of the above-mentioned elements.
Drive to combine.

The lock-up clutch piston 26 also connects a continuous annular clutch facing 37 to a part of the portion facing the converter cover 12, and the lock-up clutch piston 26 is arranged so that the clutch facing contacts the converter cover 12. When it moves, it rubs so that a chamber 38, where the internal pressure of the torque converter 1 is constantly generated, and a clutch control chamber 39 are defined on both sides of the lock-up clamp piston 26.

The clutch control chamber 39 communicates with a blind hole 40 bored in the torque converter output shaft 25, and a through hole 41 is formed in the torque converter output shaft 25, extending radially from the bottom of the blind hole.

An annular oil passage 42 is defined between the pump drive shaft 14 and the hollow fixed shaft 15, and an annular space between the hollow fixed shaft 15 and the torque converter output shaft 25 is partitioned by spacers 43 to 45 to form two annular oil passages. 46.47.

As mentioned above, the oil passage 42 is used to feed the hydraulic oil from the gear pump driven by the engine into the torque converter 1, and the hydraulic oil that has passed through the torque converter is transferred to the hollow fixed shaft 1.
5 (After flowing into the oil passage 46 through the radial hole 48 provided here, the oil passes through an oil passage (not shown), passes through a pressure retention valve, an oil cooler, etc., and is returned to the oil reservoir. The pressure is maintained.

The oil passage 47 communicates with the through hole 41 and the pump cover 9.
The oil passage 49 is connected to the oil passage 49 provided in the oil passage 49, and this oil passage is made to communicate with the communication valve 50ai of the open-up control valve 50.

The lock-up control valve also has an inlet port 50b and a drain port 50c, and the spool 51 has a spring 52.
) When the upper half of FIG. 1 is placed in the position shown in FIG. The inlet boat 50b is connected to the passage 42 or 4 for hydraulic oil brought to the internal pressure of the torque converter.
Connect 6.

Further, the chamber 53 is a drain tube 155 having an orifice 54.
and a port 56Q communicating with a line pressure circuit (not shown) of the automatic transmission, which can be appropriately closed by a plunger 58 of a lock-up control solenoid 57.

In the automatic transmission of the present invention configured as described above, the hydraulic oil flow from the pump impeller 2 driven by the engine collides with the turbine runner 3 and then the stator impeller 4, and at this time, the stator impeller 4 directional clutch 16
Since rotation in the opposite direction to the engine drive direction is prevented by the above, the hydraulic oil flow drives the turbine runner 3 while converting torque (torque increase) in the engine drive direction under the reaction force of the stator impeller 4. I can do it.

At this time, if the lock-up clutch piston 26 is separated from the converter cover 12 as shown in the first figure, the rotation of the turbine runner 3 is transmitted to the sun gear 2 via the internal gear 24 and planetary carrier 22 connected thereto.
0 in the opposite direction to the engine drive direction.

However, since the one-way clutch 21 prevents the rotation of the sun gear 20 in this direction, a rotational reaction force is generated, and as a result, the planetary gear set 17 increases the torque (decelerates) the rotation of the turbine runner 3 and removes the rotation from the carrier 24. Torque converter output shaft 25 (outputs this).

If the deceleration caused by this planetary gear set 17 is corrected by changing the final reduction ratio (a change that reduces the reduction ratio), the automatic transmission of the present invention can be realized by the planetary gear type transmission mechanism in the transmission case 6. Strain it as is.

However, in the lock amplifier release position of the lock-up clutch piston 26, it is possible to select, for example, three forward speeds and one reverse speed with the same total reduction ratio as when using a conventional automatic transmission.

To release the lock-up of the lock amplifier clutch piston 26, the solenoid 57 is deenergized and its plunger 58 is released.
continues as shown below in the right half of FIG.

That is, the drain port 53 communicates only with the drain boat 55, and the spool 51 of the valve 50 is placed in the position shown in the upper half of FIG.

As a result, the internal pressure of the torque converter, which has been guided by 50 bis, is transmitted from the baud 50a to the chamber 39 via the oil passage 49, 47, the through hole 41, and the blind hole 40, and is transmitted to the chamber 39.
Since the pressure is the same as that of the chamber 38, the lock-up clutch piston 26 is moved away from the converter cover 12 and is maintained at the lock amplifier release position.

By the way, when the vehicle speed becomes sufficiently high while driving in the third forward speed, a signal from a sensor (not shown) that detects this state is inputted to the solenoid 57, and the plunger 58 is activated as shown in FIG. The left half of the body (as shown) is aspirated to open port 56.

This generates a pressure inside the chamber 53 in the presence of the orifice 54, even though the line pressure is extracted from the drain boat 55 through the port 56, and this pressure causes the spool 51 to
resists the spring 52 and is moved to the position shown in the lower half of FIG.

Therefore, the port 50a communicates with the drain boat 50c, and from this drain boat, the pressure in the chamber 39, which has been made into the torque converter internal pressure as described above, is extracted, and the lock amplifier clutch piston 26 is moved due to the pressure difference between the chambers 3B and 39. It is shown on the left in FIG.

Therefore, the clutch facing 37 is pressed against the converter cover 12 and the lock-up clutch piston 26 is brought into the lock-up state.

In this case, the input shaft 13 includes the converter cover 12, the lock-up clutch piston 26, and the torsional damper 36.
, drive plate 27, and carrier 24 to the torque converter output shaft 25, and the power from the input shaft 13 is directly connected to the torque converter output shaft 25 through the same path without passing through the torque converter 1 and the planetary gear set 17. Axis 2
5 (is transmitted as is, and at this time, clutch engagement shock and engine rotational fluctuations are absorbed by the torsional damper 36.

Thus, in this case, the speed can be increased by the amount by which the deceleration path of the planetary gear set 17 is bypassed, and the automatic transmission of the present invention can obtain an overdrive gear position one step higher than the third forward speed.

Although the above-mentioned example shows only the case where an overdrive gear stage is added, the automatic transmission of the present invention has the same structure (the solenoid 57 is energized during driving in the first forward speed and in the second forward speed). By allowing this to occur both while driving at high speed and while driving in reverse gear, an automatic transmission with a maximum of 6 forward speeds and 2 reverse speeds can be created if necessary.

Moreover, in the present invention (here, the one-way clutch 21 for the sun gear 20 is the one-way clutch 16 for the stator impeller 4).
As shown in FIG. 4, these can be replaced with a common one-way clutch 59.

In this case, when the lock-up of the lock-up clutch piston 26 is released, the torque conversion ratio of the torque converter 1 is 1.
Near the coupling region where = 1, the sun gear 20 drives and energizes the connected stator impeller 4 in the opposite direction to the engine drive direction, thereby engaging the one-way clutch 59.
is fixed and does not allow free roll of the stator impeller, the amount of hydraulic oil collides with the stator, which slightly degrades the performance of the torque converter 1. However, since only one one-way clutch is required, the automatic transmission of the present invention The feature is that the machine can be made at low cost.

Thus, the automatic transmission of the present invention is inexpensive and easy as described above by simply adding the planetary gear set 1T and the lock-up clutch piston 26, without any troublesome and expensive changes to the planetary gear type transmission mechanism. The automatic transmission can be doubled up to a maximum, and this increase in the number of gears (because of this, the automatic transmission does not require a significant increase in weight) has extremely high feasibility.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of the automatic transmission of the present invention, and Fig. 2 is a sectional view of the main parts of the automatic transmission of the present invention.
FIG. 3 is a view taken along arrow B in FIG. 1, and FIG. 4 is a sectional view of a main part similar to FIG. 1 showing another example of the automatic transmission of the present invention. 1...Torque converter, 2...Pump impeller, 3...Turbine runner, 4...
... Stator impeller, 5 ... Converter bousing, 6 ... Transmission case,
7... Gear pump, 8... Pump housing, 9... Pump cover, 10...
・Outer gear, 11...Inner gear, 12
...Track converter cover, 13...Input shaft, 1
4...Pump drive shaft, 15...Hollow fixed shaft, 16,2L59...One-way clutch, 1
7... Planetary gear set, 18... Internal gear, 20... Sun gear, 22...
・Planetary gear, 23...shaft, 24...
...Carrier, 25...Torque converter output shaft, 26...Lock-up clutch piston,
27... Drive plate, 36...
Torsional damper, 37, Clutch facing, 38, 39... Chamber, 43-45.
... Spacer, 50 ... Lock-up control valve, 57 ... Lock-up control solenoid,
58...Plunger.

Claims (1)

[Scope of Claims] 1. A torque converter that rotates a turbine runner while converting torque under the reaction force of a stator impeller using a hydraulic oil flow from a pump impeller that rotates integrally with a human-powered shaft, the torque converter output shaft being rotated by the turbine runner. In an automatic transmission configured to drive A planetary gear set consisting of a gear and a sun gear (planetary gears that mesh with each other and a carrier that rotatably supports these planetary gears) is provided, and the carrier is coupled to the torque converter output shaft (and the input shaft is appropriately driven). An automatic transmission characterized in that driving is coupled via an engageable lock-up clutch. 2. The sun gear is drive-coupled to the stator impeller, and the one-way clutch is used as a one-way clutch for attaching the stator impeller. 3. The automatic transmission according to claim 1, characterized in that the carrier is coupled to the lock-up clutch via a torsional damper. Automatic transmission as described in section.