JPH1130323A - Accumulator device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly use two-stage and one-stage characteristics as an accumulator characteristic for the absence of back pressure, and also adjust a spring load without changing a piston stroke. SOLUTION: A first and second accumulators (C) and (d), in structure wherein a piston and a spring are assembled into a cylinder, are provided on a fastening element pressure circuit (b) to be connected to one fastening element (a); and the directions of a first and second springs (e) and (f) of both the accumulators (c) and (d) are set reversely with each other to back pressure, and also when the fastening element pressure is risen in a condition where the back pressure is applied, pressure levels, where the pistons (g) and (h) of both the accumulators (c) and (d) begin operation, are differently set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of an accumulator for an automatic transmission that produces a shelf pressure characteristic in which a rising or falling gradient is suppressed as a fastening element pressure characteristic during gear shifting.

[0002]

2. Description of the Related Art Conventionally, as an accumulator device for an automatic transmission, a device described in Japanese Patent Publication No. 5-35304 has been known.

FIG. 2 of this publication discloses an accumulator having a structure in which an intermediate position of a piston slidably provided in a cylinder is partitioned to oppose two springs. Then, when the fastening element pressure is increased in a state where the back pressure is applied, a two-stage hydraulic pressure gradient is different between a piston stroke start region where two springs work together and a piston stroke region where only one spring works. Accumulator characteristics are obtained.

[0004]

However, in the conventional accumulator for an automatic transmission, when the back pressure is drained or reduced, the spring on the compression side is compressed when the back pressure is applied. Missing or not fully compressible,
The stroke starts from the piston position where the loads of the two springs are balanced.

When the load of the spring is adjusted, the balance position of the piston also changes, so that the stroke (operating time of the accumulator) also changes.

An object of the present invention is to provide an automatic transmission in which two-stage characteristics and one-stage characteristics can be selectively used as accumulator characteristics depending on the presence or absence of back pressure, and the spring load can be adjusted without changing the piston stroke. An accumulator device is provided.

[0007]

[Means for Solving the Problems]

(Solution 1) Solution 1 of the above problem (Claim 1)
As shown in the claim correspondence diagram of FIG. 1, in an accumulator device of an automatic transmission that creates a shelf pressure characteristic in which a rising or falling gradient is suppressed as a fastening element pressure characteristic during gear shifting, a fastening element connected to one fastening element a A first accumulator c and a second accumulator d having a structure in which a piston and a spring are incorporated in a cylinder are provided in the pressure circuit b, and the directions of the first spring e and the second spring f of the accumulators c and d are set with respect to the back pressure. And the pressure levels at which the pistons g and h of the accumulators c and d start to operate when the fastening element pressure is increased with the back pressure applied. And

(Solution 2) As shown in the claim correspondence diagram of FIG. 1, a solution 2 of the above-mentioned problem (claim 2) is an accumulator device for an automatic transmission according to claim 1.
Two timing valves k, 2 are provided in the first back pressure chamber i and the second back pressure chamber j of the first accumulator c and the second accumulator d.
m and one timing solenoid n, and an accumulator back pressure circuit o for applying a back pressure or draining the back pressure by on / off control of the timing solenoid n is connected.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Embodiment 1 is an accumulator device of an automatic transmission corresponding to the first and second solving means.

First, an overall outline of an automatic transmission to which the accumulator device of the first embodiment is applied will be described.

FIG. 2 is a skeleton diagram showing a power transmission mechanism of the automatic transmission.

In FIG. 2, IN is an input shaft, OUT is an output shaft, FPG is a front planetary gear, RPG is a rear planetary gear, and the front planetary gear FPG is a first sun gear S.
1, a first ring gear R1, a first pinion P1, and a first pinion carrier C1.
Sun gear S2, second ring gear R2, and second pinion P2
And a second pinion carrier C2.

4th forward speed and 1 reverse speed using the gear train
A reverse clutch R is used as a fastening element for obtaining a high speed.
EV / C (hereinafter R / C), high clutch HIGH / C
(Hereinafter, H / C), a 2-4 brake 2-4 / B, a low clutch LOW / C (hereinafter, L / C), a low & reverse brake L & R / B, and a low one-way clutch LOW OWC.

The first sun gear S1 is connected to the input shaft IN via a first rotating member M1 and a reverse clutch R / C, and the first rotating members M1 and 2-4.
It is connected to the case K via the brake 2-4 / B.

The first carrier C1 is connected to the input shaft IN via a second rotating member M2 and a high clutch H / C, and via a third rotating member M3 and a low & reverse brake L & R / B. It is connected to the case K. The first carrier C1 is provided with a third rotating member M3.
And the second ring gear R2 via a low clutch L / C. In addition, low & reverse brake L & R /
A low one-way clutch LOW OWC is provided in parallel with B.

The first ring gear R1 is directly connected to a second carrier C2 via a fourth rotating member M4.
The output shaft OUT is directly connected to the second carrier C2.

The second sun gear S2 is directly connected to the input shaft IN.

The power transmission mechanism is characterized by 4-3
A one-way clutch that was adopted to obtain a shift timing without downshift when shifting down,
The use of this one-way clutch eliminates the use of a hydraulically-engaged clutch required to secure engine braking, and achieves a reduction in size and weight by reducing the number of fastening elements.

FIG. 3 shows the above-mentioned power transmission mechanism for four forward speeds.
FIG. 7 is a diagram illustrating engagement logic for obtaining a first reverse speed.

The first speed (1st) is a low clutch L / C
And the hydraulic engagement of the low & reverse brake L & R / B (when the engine brake range is selected) or the mechanical engagement of the low one-way clutch LOW OWC (when accelerating). That is, the second sun gear is input, the second ring gear is fixed, and the second carrier is output.

The second speed (2nd) is a low clutch L / C
And 2-4 brake hydraulic pressure 2-4 / B. That is, the input is the second sun gear input, the first sun gear fixed, and the second carrier output.

The third speed (3rd) is a high clutch H / C
And the low clutch L / C is hydraulically engaged. That is, the simultaneous input of the second ring gear and the second sun gear,
Carrier output (speed ratio = 1).

The fourth speed (4th) is a high clutch H / C
And 2-4 brake hydraulic pressure 2-4 / B. That is, the overdrive speed is set by the first carrier and the second sun gear input, the first sun gear fixed, and the second carrier output.

The reverse speed (Rev) is determined by the reverse clutch R
It is obtained by hydraulically engaging the EV / C and the low & reverse brake L & R / B. That is, the first and second sun gears are input, the first carrier is fixed, and the second carrier is output.

The 2-4 brake 2-4 / B is a multiple disc brake having the same structure as the multiple disc clutch.

FIG. 4 shows the first to fourth ranges of the D range among the above-mentioned shift stages.
FIG. 3 is a control system diagram showing a fastening element, a control valve unit, and an electronic control unit for achieving automatic speed change.

FIG. 4 shows a low clutch L as a fastening element.
/ C, a 2-4 brake 2-4 / B (corresponding to a fastening element a in the claims), and a high clutch H / C.

The control valve section of FIG. 4 includes a shift valve (A) 1, a shift valve (B) 2, an accumulation control valve (A) 3, an accumulation control valve (B) 4, and a low clutch timing valve. 5
A low clutch sequence valve 6, a 2-4 brake timing valve 7 (corresponding to a timing valve m in the claims), a 2-4 brake sequence valve 8 (corresponding to a timing valve k in the claims), and a low clutch accumulator. 9 and 2-4 brake accumulator unit 10
(Corresponding to an accumulator device) and a high clutch accumulator unit 11.

The shift valve (A) 1 and the shift valve (B) 2 are operated in the first to fourth speeds (O to O) according to the operation of the shift solenoid (A) 21 and the shift solenoid (B) 22.
The oil path is switched at each shift speed of D).

The accumulation control valve (A) 3
Is the line pressure PL according to the magnitude of the solenoid pressure PSOLA generated by the line pressure duty solenoid 23.
And accumulate control pressure (A) to adjust PACCMA. The solenoid pressure PSOLA generated by the line pressure duty solenoid 23 is also guided to a pressure modifier valve for adjusting a modifier pressure which is a signal pressure of the line pressure PL generated by a pressure regulator valve (not shown).

The accumulation control valve (B) 4
Reduces the line pressure PL in accordance with the magnitude of the solenoid pressure PSOLB generated by the 2-4 / B duty solenoid 24, and regulates the accumulation control pressure (B) PACCMB.

The low clutch timing valve 5 is
When the low clutch timing solenoid 25 is turned off, the signal pressure oil passage is set to the drain side, and when the low clutch timing solenoid 25 is turned on, the signal pressure oil passage is set to the communication side by generating hydraulic pressure.

The low clutch sequence valve 6 is
The back pressure control of the low clutch accumulator 9 is performed at the time of upshifting to the fourth speed or at the time of downshifting from the fourth speed.

The 2-4 brake timing valve 7
Means that the 2-4 brake timing solenoid 26 is OFF
The switching valve sets the signal pressure oil passage to the drain side at the time of, and sets the signal pressure oil passage to the communication side by generating oil pressure at the time of ON.

The above 2-4 brake sequence valve 8
Performs the back pressure control of the 2-4 brake accumulator 10 when shifting up to the third speed or downshifting from the third speed.

In the low clutch accumulator 9, an accumulating control pressure (A) PACCMA is guided to the back pressure chamber via a low clutch sequence valve 6, and the low clutch L / C is smoothly engaged and released.

In the 2-4 brake accumulator unit 10, the accumulator control pressure (B) PACCMB is guided to the back pressure chamber via the 2-4 brake sequence valve 8, and the 2-4 brake 2-4 / B is engaged.・ Smooth release.

The high clutch accumulator unit 11 has an accumulator control pressure (A) P in its back pressure chamber.
The ACCMA is guided as it is, and the high clutch H / C is
Smooth release.

The electronic control unit shown in FIG. 4 includes a shift solenoid (A) 21 as an actuator for controlling oil pressure in accordance with a drive command from the A / T control unit 20.
, Shift solenoid (B) 22, line pressure duty solenoid 23, 2-4 / B duty solenoid 24
And low clutch timing solenoid 25 and 2-4 / B
A timing solenoid 26 (corresponding to a timing solenoid n in the claims) is provided.

As information sources for providing input information to the A / T control unit 20, a throttle sensor 27 for detecting a throttle opening, a vehicle speed sensor 28 for detecting a vehicle speed, and a turbine sensor 2 for detecting turbine rotation are provided.
9, an oil temperature sensor 30 for detecting the oil temperature, and other sensors
Switches 31 are provided.

The shift control for automatically shifting the first to fourth speeds in the D range is based on a shift point characteristic model diagram as shown in FIG. 6 and the detected throttle opening and vehicle speed.
A shift command is issued when the vehicle crosses the upshift or upshift shift line, and the next shift gear position is determined according to the shift command, and in order to obtain the determined gear position, the shift solenoid operation table shown in FIG. 5 is obtained. A / T
Shift solenoid from control unit 20 (A)
ON or O for 21 and shift solenoid (B) 22
It is controlled by issuing an FF command.

FIG. 7 shows the 2-4 brake 2-4 / B and the 2-4 brake accumulator unit 10.

In the cylinder chamber of the 2-4 brake 2-4 / B (fastening element), a 2-4 brake pressure circuit 40 (to the fastening element pressure circuit b) is supplied with oil pressure at the second and fourth gear positions. Equivalent)
Is connected.

In the branch oil passage 40a of the 2-4 brake pressure circuit 40, the 2-4 brake accumulator unit 1
0 are provided with a first accumulator 10A and a second accumulator 10B.

The first accumulator 10A includes a first piston 10b and a first spring 10c in a first cylinder 10a.
The first piston 10b defines a first brake pressure chamber 10d and a first back pressure chamber 10e.

The second accumulator 10B includes a second piston 10g and a second spring 10h in a second cylinder 10f.
The second piston 10g defines a second brake pressure chamber 10i and a second back pressure chamber 10j.

The directions of the first spring 10c of the first accumulator 10A and the second spring 10h of the second accumulator 10B are set opposite to each other with respect to the back pressure. That is, in the first accumulator 10A, the first spring 10c is arranged on the first back pressure chamber 10e side, and in the second accumulator 10B, the second spring 10h is arranged on the second brake pressure chamber 10i side.

Then, when the 2-4 brake pressure P2-4 / B is increased by the accumulator back pressure circuit 41 while the back pressure by the accumulator control pressure (B) PACCMB is applied, the pistons 10 of the accumulators 10A and 10B are increased.
The pressure levels at which b and 10g start operating are set differently depending on spring selection (spring constant), piston selection (piston diameter), and the like.

In FIG. 7, reference numerals 42 and 43 denote orifices and one-way valves provided in parallel with the branch oil passage 40a, and reference numeral 44 denotes an air bleed for removing air bubbles in the hydraulic oil.

Next, the operation will be described.

[Accumulator back pressure control] In the accumulator back pressure control, when the OFF command is output to the 2-4 / B timing solenoid 26, the 2-4 / B timing valve 7 is set to the 2-4 brake sequence valve. 8 is switched to the side where the high clutch pressure PH / C, which is the operation signal pressure, is cut off. Accordingly, the accumulator control pressure (A) PACCMA acts on the 2-4 brake sequence valve 8 in the leftward direction in FIG. 4, so that the accumulator control pressure (B) PACCMB acts on the 2-4 brake accumulator unit 10. Back pressure remains.

On the other hand, when an ON command is output to the 2-4 / B timing solenoid 26, the 2-4 / B timing valve 7
Is switched to the side that supplies the high clutch pressure PH / C, which is the operation signal pressure, to the 2-4 brake sequence valve 8. Therefore, the 2-4 brake sequence valve 8 performs a valve switching operation when the differential pressure ΔP between the accumulation control pressure (A) PACCMA and the high clutch pressure PH / C reaches a set differential pressure, and the 2-4 brake accumulator unit 10
Accumulation control pressure (B) Back pressure by PACCMB is drained.

As described above, the two timing valves 7, 8 and the one back pressure chamber 10e are provided in the first back pressure chamber 10e and the second back pressure chamber 10j of the first accumulator 10A and the second accumulator 10B.
Since the accumulator back pressure circuit 41 provided with the 2-4 / B timing solenoid 26 is connected, the back pressure is applied or the back pressure is drained by simple on / off control of the 2-4 / B timing solenoid 26. be able to.

[Accumulator Characteristics] The accumulator characteristics of the 2-4 brake accumulator unit 10 will be described.

When the back pressure is drained, 2-4
The second accumulator 10B, in which the second piston 10g does not stroke due to the brake pressure P2-4 / B, does not operate, and the first piston 1 is not actuated by the 2-4 brake pressure P2-4 / B.
Only the first accumulator 10A that strokes 0b operates.

Therefore, at the time of the back pressure drain, as shown in FIG. 8, a single-stage accumulator characteristic is exhibited by the spring shelf pressure balanced with the spring force of the first spring 10c of the first accumulator 10A. 1 piston 10
This is the time for b to move from the upper end to the lower end.

When the back pressure is applied, the first piston 10b of the first accumulator 10A is in the position shown in FIG. 7, but the second piston 10b of the second accumulator 10B is in the position shown in FIG.
g strokes from the lower end position in FIG. 7 due to the back pressure, and is in the upper end position.

Accordingly, when the 2-4 brake pressure P2-4 / B is increased with the back pressure applied, first, the second piston 10g of the second accumulator 10B strokes from the upper end position to the lower end position. As shown in FIG. 8, a second accumulator shelf pressure characteristic in which the 2-4 brake pressure P2-4 / B is maintained at the second accumulator shelf pressure level is shown, and when the 2-4 brake pressure P2-4 / B is further increased. 8, the first piston 10b of the first accumulator 10A strokes from the upper end position to the lower end position, and as shown in FIG. 8, the first accumulator shelf for keeping the 2-4 brake pressure P2-4 / B at the first accumulator shelf pressure level. Shows pressure characteristics.

Thus, when back pressure is applied,
The two-stage accumulator characteristic is shown by the second accumulator shelf pressure and the first accumulator shelf pressure.

[Spring Adjustment] The second accumulator shelf pressure and the first accumulator shelf pressure are obtained by a balance equation of a force based on a back pressure, a piston pressure receiving area, and a spring load (spring force).

Therefore, when the shelf pressure level is desired to be maintained or the shelf pressure level is to be changed with respect to the change in the back pressure, the spring adjustment for changing the spring load is performed.

In this spring adjustment, the first spring 10c and the second
The spring 10h is replaced.
Since the spring 10c and the second spring 10h are independently set without affecting each other, the piston stroke does not fluctuate due to the spring adjustment unlike the conventional one-piston two-spring structure.

Next, the effects will be described.

(1) An accumulator back pressure circuit 41 connected to one 2-4 brake 2-4 / B is provided with a first accumulator 10A and a second accumulator 10B having a structure in which a piston and a spring are incorporated in a cylinder. , The first spring 10c and the second spring 10 of both accumulators 10A, 10B
h are set opposite to each other with respect to the back pressure, and when the 2-4 brake pressure P2-4 / B is increased with the back pressure applied, the pistons 10 of the accumulators 10A and 10B are increased.
Since the pressure levels at which b and 10g start to operate are set differently, two-stage characteristics and one-stage characteristics can be used as accumulator characteristics depending on the presence or absence of back pressure, and the spring load can be adjusted without changing the piston stroke. An automatic transmission 2-4 brake accumulator unit 10 can be provided.

(2) First back pressure chamber 10e and second back pressure chamber 10 of first accumulator 10A and second accumulator 10B
Since the accumulator back pressure circuit 41 provided with two timing valves 7 and 8 and one 2-4 / B timing solenoid 26 is connected to j, a simple operation for the 2-4 / B timing solenoid 26 is performed. The back pressure can be applied or the back pressure can be drained by on / off control.

(Other Embodiments) The accumulator device of the present invention is not limited to the automatic transmission shown in the first embodiment, but may be replaced by an accumulator provided as a hydraulic adjustment means for a fastening element in various types of automatic transmissions. Can be applied.

[0067]

According to the first aspect of the present invention, in an accumulator device for an automatic transmission, which produces a shelf pressure characteristic in which a gradient of rising and falling is suppressed as a fastening element pressure characteristic at the time of shifting, it is connected to one fastening element. First, a structure in which a piston and a spring are incorporated in a cylinder in the fastening element pressure circuit
An accumulator and a second accumulator are provided, the directions of the first spring and the second spring of both accumulators are set to be opposite to each other with respect to the back pressure, and when the fastening element pressure is increased with the back pressure applied, Since the pressure level at which the piston of the accumulator starts to operate is set differently, the two-stage characteristic and the one-stage characteristic can be used as accumulator characteristics depending on the presence or absence of back pressure, and the spring load can be adjusted without changing the piston stroke. The effect is obtained that an accumulator device for an automatic transmission can be provided.

According to the second aspect of the present invention, there is provided the first aspect.
The accumulator device for an automatic transmission according to claim 1,
The first back pressure chamber and the second back pressure chamber of the accumulator and the second accumulator have two timing valves and one timing solenoid.
Since an accumulator back pressure circuit that inputs back pressure or drains back pressure by off control is connected, in addition to the above effects,
Simple two-stage and one-stage characteristics can be used as accumulator characteristics by simple on / off control of the timing solenoid.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing an accumulator device of an automatic transmission according to the present invention.

FIG. 2 is a skeleton diagram showing a power transmission mechanism of the automatic transmission to which the hydraulic control device according to the first embodiment is applied.

FIG. 3 is a diagram illustrating a fastening logic table of the automatic transmission to which the hydraulic control device according to the first embodiment is applied.

FIG. 4 is an overall system diagram showing a hydraulic control unit and an electronic control unit to which the accumulator device of the first embodiment is applied.

FIG. 5 is a diagram showing a shift solenoid operation table of the hydraulic control device according to the first embodiment.

FIG. 6 is a diagram illustrating an example of a shift point characteristic model of the hydraulic control device according to the first embodiment.

FIG. 7 is an accumulator device according to the first embodiment;
It is a figure showing a 4 brake accumulator unit.

FIG. 8 is an accumulator characteristic diagram of a 2-4 brake accumulator unit according to the first embodiment.

[Explanation of symbols]

 a fastening element b fastening element pressure circuit c 1st accumulator d 2nd accumulator e 1st spring f 2nd spring g, h piston i 1st back pressure chamber j 2nd back pressure chamber k, m Timing valve n Timing solenoid

Claims (2)

[Claims] 1. An accumulator device for an automatic transmission for producing a shelf pressure characteristic in which a rising or falling gradient is suppressed as a fastening element pressure characteristic during a shift, wherein a fastening element pressure circuit connected to one fastening element includes A first accumulator and a second accumulator having a structure incorporating a piston and a spring are provided, and the directions of the first spring and the second spring of both accumulators are set to be opposite to each other with respect to the back pressure, and the back pressure is applied. An accumulator device for an automatic transmission, wherein the pressure levels at which the pistons of both accumulators start operating when the fastening element pressure is increased are set differently. 2. The accumulator device for an automatic transmission according to claim 1, wherein two timing valves and one timing are provided in the first back pressure chamber and the second back pressure chamber of the first accumulator and the second accumulator. An accumulator device for an automatic transmission, comprising a solenoid, and connected to an accumulator back pressure circuit for applying back pressure or draining back pressure by on / off control of the timing solenoid.