JPH05296346A - Hydraulic controller of automatic transmission - Google Patents

Abstract

PURPOSE:To directly control the engaging pressure of a friction clutch device and miniaturize the hydraulic pressure controller of an automatic transmission by providing a plunger to axially move the valve body, which is movably contained between two valve seats and selectively closes the valve seats, back and forth due to magnetic force. CONSTITUTION:An electromagnetic valve 30 controlling the supply and discharge of hydraulic pressure to a third brake B3 has valve seats 37 and 39 which oppose to each other, ball 40 movably contained between the valve seats 37 and 39 and selectively closing the valve seats 37 and 39, an output port 41 to which the third brake B3 is connected and opens between the valve seats 37 and 39 and a plunger 33, which is made to axially move back and forth due to magnetic power by advancing from the valve seat 37 toward the valve seat 39 so as to press the ball 40 to the valve seat 39. An oil passage, to which hydraulic pressure is supplied by one of two speed change steps, is connected to a port 42 whose opening end comprises the valve seat 37. Another oil passage, to which hydraulic pressure is supplied by the other speed change step out of the two speed change steps, is connected to another port 38 whose opening end comprises the valve seat 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for controlling a shift in an automatic transmission of a vehicle, and more particularly to a valve for switching two fluid supply / drain portions to one friction engagement device for communication. It is about.

[0002]

2. Description of the Related Art As is well known, gear shifting in an automatic transmission is executed by engaging or disengaging a friction engagement device such as a clutch or a brake. There are some gears that are engaged at two different gear stages, and in this type of friction engagement device, it is necessary to make the transient characteristics during gear shift different for each gear stage.

For example, FIG. 3 shows a gear train of an automatic transmission in which four forward gears and one reverse gear can be set, and this gear train is overlaid with a third speed transmission unit 1 for performing three forward gears. A drive unit (O / D unit) 2 is provided. That is, the third speed transmission unit 1 includes the first planetary gear mechanism 3 and the second planetary gear mechanism 4
And the respective sun gears 5 and 6 are connected by a sun gear shaft 7, and the sun gear shaft 7 is connected to an input shaft 8 via a second clutch C2, and the sun gear shaft 7 is connected to the outer periphery of the clutch drum of the second clutch C2. A first brake B1 which is a band brake is provided. A first clutch C1 is arranged between the ring gear 9 of the first planetary gear mechanism 3 and the input shaft 8. Further, a first one-way clutch F1 and a second brake B2, which are arranged in series with each other, are arranged between the sun gear shaft 7 and the casing 10. The carrier 11 of the first planetary gear mechanism 3 and the ring carrier 12 of the second planetary gear mechanism 4 are connected so as to rotate integrally, and between the carrier 13 of the second planetary gear mechanism 4 and the casing 10, A second one-way clutch F2 and a third brake B3 are provided which are arranged in parallel with each other.

The O / D section 2 is provided with a set of planetary gear mechanisms 14, the carrier 15 of which is connected to the carrier 11 of the first planetary gear mechanism 3 and the ring gear 12 of the second planetary gear mechanism 4 and also the ring gear 16. Is connected to the counter drive gear 17, which is an output member. A one-way clutch F0 and a clutch C0 which are in parallel with each other are arranged between the sun gear 18 and the carrier 15, and a brake B0 is provided between the sun gear 18 and the casing 10. In this automatic transmission, each of the friction engagement devices is engaged as shown in the operation table of FIG. 4, whereby four forward speeds and one reverse speed can be set.

The third brake B3 in the above-described automatic transmission needs to be engaged in the reverse gear and the first speed in the L range, but the reverse gear is a neutral position where no torque is input to the third speed gear unit 1. Since the third brake B3 is set by switching from the range, shift shock does not occur even if the third brake B3 is engaged without adjusting its engagement hydraulic pressure. On the other hand, at the first speed in the L range, it is necessary to engage the third brake B3 while the first clutch C1 is engaged and the torque has already been input to the third speed transmission unit 1. It is necessary to engage the 3 brake B3 while adjusting the hydraulic pressure. Therefore, in the conventional hydraulic control device using the shift valve, the oil passage for supplying the hydraulic pressure to the third brake B3 is switched by the shift valve and the manual valve.

Recently, a so-called direct control hydraulic control system for an automatic transmission, which supplies and discharges hydraulic pressure to a friction engagement device and its transient control by a single solenoid valve, is being developed. It is described in JP-A-3-163265. In this type of hydraulic control device, each solenoid valve can control the engagement / disengagement of the friction engagement device and the transient control of its hydraulic pressure, but cannot change the oil passage, and therefore the above-mentioned For the friction engagement device that is engaged in a different range like the third brake B3,
Generally, a shuttle type check ball valve is used to switch the oil pressure supply oil passage in each range or speed. This is schematically shown in FIG. 5, in which the R range port 21 of the manual valve 20 is connected to the third brake B3 via the shuttle type check ball valve 22, and the L range port 23 of the manual valve 20 is connected. Is connected to, for example, a duty-controlled solenoid valve 24, and this solenoid valve 24 is connected to the third brake B3 via the shuttle type check ball valve 22.

[0007]

In the above-mentioned so-called direct control type hydraulic control device, since the shift valve, the accumulator, etc. can be eliminated, the hydraulic control device can be made smaller and lighter to some extent. It is necessary to newly add a check ball valve 22 of a mold, which causes an increase in weight or an obstacle to downsizing, and there is room for further improvement in this respect.

The present invention has been made in view of the above circumstances, and provides a hydraulic control device capable of directly controlling the engagement pressure of a friction engagement device and further reducing the size and weight. The purpose is.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to an automatic transmission including a friction engagement device to which hydraulic pressure is supplied and engaged at two gear stages having different traveling ranges. In the hydraulic control device, a valve that controls the supply and discharge of hydraulic pressure to and from the friction engagement device is provided with two valve seats formed facing each other and movably accommodated between these valve seats. A valve body that selectively closes a valve seat, an output port that is connected to the friction engagement device and that is formed so as to open between the valve seats, and from the one valve seat side toward the other valve seat. A plunger that is moved forwards and backwards in the axial direction by a magnetic force so as to press the valve element against the other valve seat, and one port with the one valve seat as the open end has one of the two shift speeds. Oil passage to which hydraulic pressure is supplied at one of the gears Another oil passage connected to the other port of which the other valve seat is an open end and to which hydraulic pressure is supplied at the other gear of the two gears is connected. Is.

Further, according to the present invention, a switching valve for selectively outputting a hydraulic pressure for effecting engine braking at a predetermined low speed stage and a hydraulic pressure for setting a reverse speed stage is provided, and the oil passage is provided at the one port. Is configured to supply a hydraulic pressure for setting the reverse gear via, and to supply the hydraulic pressure for applying the engine brake to the other port via the other oil passage at the predetermined low speed gear, Furthermore, the friction engagement device may be a friction engagement device that is engaged when the engine brake is applied at the predetermined low speed stage and when the reverse stage is set.

[0011]

In the valve used in the hydraulic control device of the present invention, the plunger moves forward to press the valve element against the other valve seat to close the other port, so that the hydraulic pressure in the same direction as the plunger is applied. When the hydraulic pressure is supplied from the one port for applying the pressure, the valve body is pressed against the other valve seat by the hydraulic pressure to close the valve seat. That is, with respect to the hydraulic pressure supplied from the other port, the supply and stop can be controlled by the plunger, and the hydraulic pressure supplied can be controlled by performing the opening and closing by the plunger at high speed and controlling the opening / closing rate per unit time. When the hydraulic pressure is supplied from the one port, the valve body remains pressed against the other valve seat, and the one port communicates with the output port, so that the hydraulic pressure is supplied from the one port. The hydraulic pressure can be directly supplied to the friction engagement device. That is, by setting the hydraulic pressures supplied through these ports to the hydraulic pressures supplied at the shift speeds having different ranges, the supply speeds of those hydraulic pressures, that is, the engagement transient characteristics of the friction engagement device at those shift speeds. Can be controlled differently.

[0012] Particularly, the transitional characteristics of the friction engagement device greatly differ between the reverse gear and the low gear where engine braking is effective, but in the hydraulic control device of the present invention, the reverse gear and the low gear are controlled by the one valve. It is possible to perform hydraulic pressure supply control suitable for

[0013]

1 is a partial hydraulic circuit diagram showing an embodiment of the present invention, a valve 30 shown in FIG. This is for controlling the third brake B3 in the automatic transmission shown. That is, the valve 30 is the electronic control unit 3
1 is a solenoid valve for advancing the plunger 33 downward in FIG. 1 by the solenoid 32 which is controlled to be turned on / off by 1. When the solenoid 33 is not energized, the plunger 33 moves backward to supply hydraulic pressure to the third brake B3. It is configured as an open type. A casing 36 integrally formed with a cylindrical protrusion 35 is attached to the opening of the coil chamber 34 that houses the solenoid 32 and the rear end of the plunger 33. The tip of the plunger 33 has a cylindrical shape. Is inserted in the protrusion 35.

A ring-shaped discharge side valve seat 37 is provided at an intermediate portion inside the cylindrical protruding portion 35, while an open end of the protruding portion 35 is provided with a supply port 38.
The supply side valve seat 39 is provided so as to face the discharge side valve seat 37 on the same axis. And these valve seats 37,
A ball 40 such as a steel ball serving as a valve body is movably accommodated between 39. Further, the projecting portion 35 is formed with an output port 41 formed by penetrating in the radial direction so as to open between the discharge side valve seat 37 and the supply side valve seat 39, and sandwiching the discharge side valve seat 37. A drain port 42 is formed so as to penetrate in the radial direction on the side opposite to the output port 41.

Further, a valve seat 43 for sealing is formed on the opposite side of the drain side valve seat 37 with the drain port 42 in between, that is, in the inner part of the cylindrical protrusion 35, and the plunger 3 is formed.
A flange-shaped seal member 44, which closes the coil chamber 34 with respect to the drain port 42, is attached to the plunger 33 in close contact with the sealing valve seat 43 in a state in which 3 is retracted. The diameter D1 of the pressure receiving surface of the seal member 44 on which the hydraulic pressure from the drain port 42 acts is set as follows. That is, in FIG. 2, the line pressure PL pushes the plunger 33 upward through the ball 40 in FIG. 1, if the diameter of the pressure receiving surface of the ball 40 in close contact with the supply side valve seat 39 is D0 ( π · D0 ² · PL / 4), and therefore the downward force of the plunger 33 in FIG. 1 is set to be larger than the pushing force by the line pressure PL from the supply port 38.
At the time of electrical failure, the hydraulic pressure supplied from the drain port 42 needs to push up the plunger 33 against the downward force of the plunger 33, so that the diameter D1 of the pressure receiving surface of the seal member 44 is eventually determined by the supply port. It is set to be larger than the diameter D0 of the pressure receiving surface of the ball 40 on the 38 side.

Of the cylindrical protrusion 35, the plunger 3
The inner diameter D2 of the portion that simply penetrates 3 is set to a small value within a possible range in order to reduce oil leakage as much as possible when the plunger 33 sticks.

A third brake B3 shown in FIG. 3 is connected to the output port 41, and the supply port 3
8 is connected to the L range port 46 of the manual valve 45, and the drain port 42 is connected to the manual valve 4
5 reverse (R) range port 47 is connected. The manual valve 45 is a valve similar to that used in a conventional hydraulic control device for an automatic transmission, and when the drive (D) range is selected, the input to which the line pressure PL is supplied is supplied. If you select the S range that connects the port 48 to the D range port 49 and applies the engine brake at the second speed, the D range port 4
9 and the S range port 50 are connected to the input port 48, and when the L range in which the engine brake is effective at the first speed is selected, the D range port 49, the S range port 50, and the L range port 46 are input. The R range port 47 is communicated with the input port 48 when the R range is selected.
Furthermore, except for these communication relationships, each range port 4
6, 47, 48, 49.50 are drain ports 51, 52
Communicate with.

As described above, since the third brake B3 is engaged in the first speed of the L range and the R range, the operation of setting these shift speeds will be described. First, when the L range is selected. Has a manual valve 45
The line pressure PL is output from the L range port 46 of the solenoid valve 30 and sent to the supply port 38 of the solenoid valve 30, and the R range port 47 communicates with the drain port 51.
The pressure is exhausted from the drain port 42 of. On the other hand, the solenoid 32 is controlled by the electronic control unit 31, and if it is in the energized state, that is, in the ON state, the plunger 33 is attracted to the lower side of FIG. Close 38. In the non-energized state, that is, in the off state, the line pressure PL supplied to the supply port 38 is transmitted through the ball 40 to the plunger 33.
Is pushed upward in FIG. 1, the ball 40 is separated from the supply side valve seat 39 to open the supply port 38. Therefore, by controlling the on / off rate of the solenoid 32 per unit time, that is, by controlling the duty of the solenoid valve 30, the hydraulic pressure supplied from the output port 41 to the third brake B3 can be controlled, and the first range of the L range can be controlled. It is possible to improve the shift shock by performing the transient control when setting the speed.

On the other hand, when the R range is selected, the line pressure PL is supplied from the R range port 47 of the manual valve 45 to the drain port 42 of the solenoid valve 30, and the L range port 46 is connected to the drain port 52. It is communicated and exhausted from here. Therefore, the pressure on the upper side in FIG. 1 is high and the pressure on the lower side in FIG.
The line pressure PL, that is, the R range pressure, is pressed against the supply side valve seat 39 to close the supply port 38, and the drain port 42 communicates with the output port 41. This state occurs regardless of the energized / de-energized state of the solenoid 32. Therefore, if the R range is selected by the manual valve 45, the hydraulic pressure is immediately supplied to the third brake B3 and the third brake B3 is engaged.

Thus, the transient state of the hydraulic pressure supplied to the third brake B3 can be made different between the case of setting the L range and the case of setting the R range, which is shown in FIG.
The operation is the same as that obtained by using the conventional shuttle-type check ball valve shown in FIG. 1, and thus the conventional shuttle-type check ball valve can be omitted in the configuration shown in FIG.

When the solenoid is still energized due to an electrical failure, the plunger 33 will move to the position shown in FIG.
As shown in the right half of the figure, the pressure drops, but when the line pressure PL is supplied from the drain port 42 in this state,
Since the pushing force which is larger than the magnetic attraction force acting on the plunger 33 acts on the seal member 44 attached to the plunger 33, the plunger 33 moves upward as shown in the left half of FIG. Since 44 is in close contact with the sealing valve seat 43 and closes it, hydraulic pressure is prevented from leaking to the outside from the coil chamber 34 or here.

In the above embodiment, the solenoid valve for controlling the third brake in the gear train shown in FIG. 3 has been described as an example, but the present invention is not limited to the above embodiment, and other embodiments are possible. The present invention can be applied to a hydraulic control device intended for an automatic transmission having a gear train.

In the above embodiment, the normally open type solenoid valve has been described as an example. However, in the present invention, the plunger is pushed forward by the spring and is retracted by the magnetic force, so that It may be configured as a normally closed type in which the output port communicates with the drain port when energized.

[0024]

As described above, according to the hydraulic control system of the present invention, the valve for supplying and discharging hydraulic pressure to and from the friction engagement device engaged at the two shift stages having different travel ranges moves through the oil passage. Since it has the same function as the check ball valve for switching, the check ball valve conventionally provided separately from the hydraulic control valve can be eliminated. Therefore, according to the present invention, the hydraulic control device can be made smaller and lighter. You can In particular, according to the present invention, since it is possible to simply control the supply and discharge of the hydraulic pressure and the transient control of the hydraulic pressure, the friction to be engaged between the reverse speed stage requiring the rapid supply of the hydraulic pressure and the low speed stage where the engine brake is applied. This is effective when controlling the hydraulic pressure of the engagement device.

[Brief description of drawings]

FIG. 1 is a partial hydraulic circuit diagram for explaining an embodiment of the present invention.

FIG. 2 is a partially enlarged view thereof.

FIG. 3 is a skeleton diagram showing a gear train of an automatic transmission targeted in the embodiment.

FIG. 4 is an engagement operation table of the friction engagement device.

FIG. 5 is a schematic partial hydraulic circuit diagram of an example of a conventional so-called direct control hydraulic control device.

[Explanation of symbols]

 30 Solenoid valve 33 Plunger 37 Discharge side valve seat 38 Supply port 39 Supply side valve seat 40 Ball 41 Output port 42 Drain port 45 Manual valve

Claims (2)

[Claims] 1. A hydraulic control device for an automatic transmission, comprising a friction engagement device that is supplied with and engaged with hydraulic pressure at two speed stages having different travel ranges, wherein the hydraulic pressure is supplied to or discharged from the friction engagement device. The valve that controls
Two valve seats formed facing each other, a valve body movably accommodated between these valve seats to selectively close each valve seat, the friction engagement device is connected, and the valve is connected. An output port formed so as to open between the seats, and an axial forward / backward movement by a magnetic force so as to advance from the one valve seat side toward the other valve seat and press the valve body against the other valve seat. A plunger that is made to move, and an oil passage to which hydraulic pressure is supplied at one of the two shift stages is connected to one port with the one valve seat as an open end,
And another oil passage to which hydraulic pressure is supplied at the other gear stage of the two gear stages is connected to the other port having the other valve seat as an open end. Hydraulic control device. 2. A switching valve for selectively outputting a hydraulic pressure for applying an engine brake at a predetermined low speed stage and a hydraulic pressure for setting a reverse stage, and the one port is provided with the oil passage through the oil passage. The hydraulic pressure for setting the reverse gear is supplied, and the other port is configured to be supplied with the hydraulic pressure for applying the engine brake at the predetermined low speed via the other oil passage. The automatic transmission according to claim 1, wherein the friction engagement device is a friction engagement device that is engaged when the engine brake is applied at the predetermined low speed and when the reverse speed is set. Hydraulic control device.