JPH1137280A - Lock-up controller of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lock-up controller of an automatic transmission, for achieving smooth lock-up control while achieving profitability of cost, a space and the weight by common use of a solenoid. SOLUTION: An automatic transmission is provided with a lock-up control valve (c) for achieving smooth lock-up by temporarily making the half clutch operation by the drain adjustment of torque converter release pressure when a lock-up clutch (b) is shifted from the releasing state to the fastening state, a shift valve (d) for performing switching of oil passages in shifting and one common-use solenoid (e) for generating solenoid output pressure to both valves (c), (d). In this case, a releasing time adjusting means (h) for controlling the releasing time of torque converter release pressure is provided on a drain passage (g) connected to a drain port (f) of the lock-up control valve (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock-up control device for an automatic transmission in which a shift control and a lock-up control are simultaneously controlled by a solenoid output pressure from a single shared solenoid that shares a lock-up solenoid and a shift solenoid. Belongs to the technical field.

[0002]

2. Description of the Related Art A conventional automatic transmission lock-up control device having a back-pressure regulating type lock-up control valve for achieving smooth lock-up is shown in FIG.
As shown in (1), there is known a lock-up control valve in which a lock-up duty solenoid is exclusively installed to operate the lock-up control valve.

In this conventional apparatus, the duty width of the lock-up duty solenoid can be fully used from 0% to 100%. Therefore, as shown in FIG. 9, the torque converter release pressure PT / CR with respect to the duty solenoid output pressure PL / U DUTY SOL. Since the gain (slope) of the torque converter release pressure PT / CR can be gradually reduced, the torque converter release pressure PT / CR is required when shifting the lock-up clutch from the disengaged state to the engaged state.
By the adjustment of, a smooth and smooth lockup in which the clutch is temporarily half engaged can be achieved.

However, since this conventional device uses a dedicated lock-up duty solenoid, for example, one line pressure duty solenoid and two
In an electronically controlled automatic transmission that achieves four forward speeds by using four shift solenoids, four solenoids are required, which is disadvantageous in terms of cost, space, and weight.

To solve this problem, as a lock-up control device for an automatic transmission, as disclosed in JP-A-1-199061, a lock-up solenoid and a shift solenoid share one common solenoid. There is a known type that performs simultaneous control of shift control and lock-up control by a solenoid output pressure.

[0006]

However, the lock-up control device for an automatic transmission described in Japanese Patent Application Laid-Open No. Hei 1-1199061 is shown in FIG. 10 because the lock-up solenoid and the shift solenoid are shared. In this way, the duty control width that can be used for lock-up control is limited, and as a result, the gain of the torque converter release pressure PT / CR with respect to the solenoid output pressure PSOL increases, and the back-pressure regulation type lock-up aiming for smooth lock-up Even if the control valve is used, smooth and smooth lockup control cannot be performed sufficiently.
As shown in FIG. 1, there is a problem that the lock-up shock increases as much as the ON-OFF lock-up control.

An object of the present invention is to provide a lock-up control device for an automatic transmission that achieves smooth and smooth lock-up control while achieving advantages in cost, space, and weight by sharing a solenoid. It is in.

[0008]

[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, a lock-up clutch b which is installed in a torque converter a and can directly connect an input / output shaft by fastening, and a solenoid output pressure is used as an operation signal pressure, and the lock-up clutch b is released. When shifting from the state to the engaged state, a lock-up control valve c that temporarily achieves a smooth and smooth lock-up as a half clutch by drain adjustment of the torque converter release pressure, and the solenoid output pressure as the operation signal pressure, Shift valve d for switching oil passage
A lock-up solenoid that generates a solenoid output pressure to the lock-up control valve c, and one shared solenoid e that shares a shift solenoid that generates a solenoid output pressure to the shift valve d. In the automatic transmission, a drain oil passage g connected to a drain port f of the lock-up control valve c is provided with a release time adjusting means h for controlling a release time of a torque converter release pressure.

(Solution 2) In the lockup control device for an automatic transmission according to the first aspect, the second aspect of the present invention provides a lock-up control device for an automatic transmission, wherein the disconnection time adjusting means h is provided by disconnecting the drain oil passage g. It is characterized by an orifice that reduces the area.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Embodiment 1 is a lockup control device for an automatic transmission according to the first and second aspects of the present invention.

First, an overall outline of an automatic transmission to which the lockup control device according to 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, T / C is a torque converter, LU / C is a lock-up clutch, AP is a torque converter apply pressure chamber, REL is a torque converter release pressure chamber, IN is a transmission input shaft, and OUT is a transmission output. The shaft, FPG is a front planetary gear, RPG is a rear planetary gear, and the front planetary gear FPG is a first sun gear S1.
, A first ring gear R1, a first pinion P1, and a first pinion carrier C1, and the rear planetary gear RPG has a second sun gear S2, a second ring gear R2, a second pinion P2, and a second pinion carrier C2.

Fourth forward speed, reverse 1 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 transmission input shaft IN via a first rotating member M1 and a reverse clutch R / C, and has a first rotating member M1 and a 2-4 brake 2-4 /. It is connected to the case via B.

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

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

The second sun gear S2 has a transmission input shaft I
It is directly connected to N.

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 automatic shift control of the first to fourth speeds in the D range among the above-mentioned shift speeds is performed based on a shift point characteristic model diagram as shown in FIG. 5 and the detected throttle opening and vehicle speed. When the vehicle crosses the shift line, a shift command is issued, and the next gear position to be shifted is determined according to the shift command. In order to obtain the determined gear position, the A / T control unit is operated according to the shift solenoid operation table shown in FIG. Shift solenoid (A) not shown from 10
And the common solenoid (B) 22 is controlled by issuing an ON or OFF command. The shift solenoid (A) switches the shift valve (A) (not shown), and the common solenoid (B) 22 switches the shift valve (B) 21.

FIG. 6 shows a lock-up control circuit.
In FIG. 6, T / C is a torque converter, LU / C is a lock-up clutch, AP is a torque converter apply pressure chamber, REL is a torque converter release pressure chamber,
Is an A / T control unit, 20 is a lock-up control valve, 21 is a shift valve (B), and 22 is a common solenoid (B).

The lock-up clutch LU / C is installed in the torque converter T / C. During lock-up, the hydraulic pressure in the torque converter release pressure chamber REL is released.
This clutch is engaged by a differential pressure between the torque converter apply pressure chamber AP and directly connects the engine crankshaft (input shaft) and the transmission input shaft IN (output shaft).

The lock-up control valve 20
Are the pilot pressure Pp, the release pressure PREL, and the solenoid output pressure PSO supplied through the shift valve (B) 21.
LB is a valve operating signal pressure, and is a valve for controlling the oil pressure of the torque converter apply pressure chamber AP and the torque converter release pressure chamber REL. The valve hole 20a and the spool 20b provided in the valve hole 20a so as to be movable in the axial direction.
A spring 20c for urging the spool 20b leftward in the drawing, a drain port 20d, a pilot pressure port 20e, a lubrication pressure port 20f, an apply pressure port 20g, a converter pressure port 20h, and a release pressure formed in the valve hole 20a. Port 20i, drain port 20
j, a feedback pressure port 20k, and a lock-up control pressure port 20m. The pilot pressure oil passage 30 is connected to the pilot pressure port 20e, the lubrication pressure oil passage 31 is connected to the lubrication pressure port 20f, the apply pressure oil passage 32 is connected to the apply pressure port 20g, and the converter pressure The converter pressure oil passage 33 is connected to the port 20h, the release pressure oil passage 34 is connected to the release pressure port 20i, the drain oil passage 35 is connected to the drain port 20j, and the first orifice is connected to the feedback pressure port 20k. The release pressure oil passage 34 is connected via 41, and the lock-up control pressure oil passage 36 is connected to the lock-up control pressure port 20m. The lubrication pressure oil passage 31 is different from the apply pressure oil passage 32 in the second orifice 4.
2 and the converter pressure oil passage 33 via a third orifice 43.

The shift valve (B) 21 uses the pilot pressure Pp and the solenoid B pressure PSOLB as a valve operating signal pressure, and in the first and second speeds, the spool 21b is moved from the position shown in FIG. Switch to
In the third and fourth speeds, the valve is switched to the position shown in FIG.
A spool 21b provided in the valve hole 21a so as to be movable in the axial direction, a spring 21c for urging the spool 21b upward in the drawing, a drain port 21d, a pilot pressure port 21e, and a solenoid formed in the valve hole 21a. It has an output pressure port 21f, a lock-up control pressure port 21g, a pilot pressure port 21h, and a solenoid output pressure port 21i. The pilot pressure oil passage 30 is connected to the pilot pressure port 21e via a fourth orifice 44, and the solenoid output pressure oil passage 37 is connected to the solenoid output pressure ports 21f and 21i via a fifth orifice 45. The lock-up control pressure oil passage 36 is connected to the lock-up control pressure port 21g, and the pilot pressure oil passage 30 is connected to the pilot pressure port 21h.

The common solenoid (B) 22 has an A / T
A lock-up solenoid that generates a solenoid output pressure PSOLB to the lock-up control valve 20 via the shift valve (B) 21 at the 3rd and 4th speeds according to a duty drive command from the control unit 10 and to the shift valve (B) 21 The solenoid output pressure PSOLB becomes PSOLB ≒ Pp when not energized (OFF DUTY 100%), and is energized (OF
The solenoid output pressure PSOLB is PSOLB ≒ 0 at F DUTY 0%), and it is a normally high type solenoid.

The lock-up control valve 20
Oil passage 35 connected to the drain port 20j of the
Is provided with a sixth orifice 46 (release time adjusting means) for controlling the release time of the torque converter release pressure PREL by reducing the oil passage sectional area.

Next, the operation will be described.

[1st and 2nd speed] At 1st and 2nd speed, the A / T control unit 10
The OFF DUTY 0% drive command (energized state) is output, and the solenoid output pressure PSOLB becomes PSOLB ≒ 0. For this reason, the valve actuation signal pressure of the shift valve (B) 21 is only the pilot pressure Pp acting on the pilot pressure port 21e, the spool 21b is at the lower position where the spring 21c is pressed and contracted, and the lock-up control pressure port 21g and the pilot The communication is made with the pressure port 21h.

Therefore, the pilot pressure Pp is guided from the pilot pressure oil passage 30 to the lock-up control pressure port 20m of the lock-up control valve 20 via the shift valve (B) 21 and the lock-up control pressure oil passage 36.

In the lock-up control valve 20, when the pilot pressure Pp for pushing the spool 20b leftward in FIG.
When 0c is extended to the position shown in FIG. 6, the converter pressure PT / C is supplied to the torque converter release pressure chamber REL, and the lock-up clutch LU / C maintains the released state.

[3rd and 4th speed] At the 3rd and 4th speed, the A / T control unit 10
A drive command (non-energized state) of OFF DUTY 100% is output, and the solenoid output pressure PSOLB becomes PSOLB ≒ Pp. For this reason, the valve operation signal pressure of the shift valve (B) 21 is changed between the pilot pressure port 21 e and the solenoid output pressure port 2.
The pilot pressure Pp acting on the solenoid 1i and the large pressure receiving area on the solenoid output pressure port 21i side causes the spool 21b to assume the position shown in FIG. 6 above with the spring 21c extended, and the lock-up control pressure port 21g and the solenoid output pressure The communication with the port 21f is established.

Therefore, the lock-up control pressure port 20m of the lock-up control valve 20 has a solenoid output pressure PSO generated by the common solenoid (B) 22.
LB (≒ pilot pressure Pp) is lock-up control pressure oil passage 3
6 is led.

In the lock-up control valve 20, the spool 20b is actuated by a solenoid output pressure PSOLB (≒ Pp) which pushes the spool 20b leftward in FIG.
6B is the position shown in FIG. 6 where the spring 20c is extended, the converter pressure PT / C is supplied to the torque converter release pressure chamber REL, and the lock-up clutch LU / C keeps the released state.

[At the time of lock-up at the third, fourth or fourth speed] Lock-up control for engaging the lock-up clutch LU / C is performed at the third, fourth, or fourth speed preset in the A / T control unit 10. Is performed depending on whether or not a driving condition (lock-up condition) to be a lock-up region is satisfied.

When the lock-up condition is satisfied, A /
The solenoid output pressure PSOLB generated by the drive command from the T control unit 10 is not pushed back by the force of the pilot pressure Pp which is the counter pressure of the spool 21b of the shift valve (B) 21, and the spool 20b of the lock-up control valve 20 When the pressure is reduced to the hydraulic pressure Pα (FIG. 7) which is pushed back by the pilot pressure Pp (FIG. 7) (OFF DUTY is reduced from 100% to α%), the spool 20b opposes the spring 20c and the right of FIG. Stroke in the direction
i and the drain port 20j, and the lock-up state is established because the torque converter release pressure PREL drains.

At this time, the A / T control unit 10
By gradually lowering the OFF DUTY from, the torque converter release pressure PREL is gradually lowered. However, since the solenoid is used as the shared solenoid (B) 22, the range of the solenoid output pressure PSOLB that can be used for lock-up control is Pp to Pα corresponding to 100% to α% of OFF DUTY. As described above, the gain becomes large, and it is not possible to perform sufficiently smooth lockup control.

Therefore, the torque converter release pressure PRE
A sixth orifice 46 is provided in the drain oil passage 35 of L and the passage cross-sectional area of the drain oil passage 35 is narrowed to lengthen the drain time and delay the slip response. Thus, even though the control range of the solenoid output pressure PSOLB is limited by the use of the common solenoid (B) 22, the torque converter release pressure PREL is gradually reduced, and the lock-up clutch LU / C is shifted from the released state to the engaged state. At the time of shifting, the clutch is temporarily half-engaged, and smooth smooth lockup without lockup shock can be achieved (FIG. 7).

Next, the effects will be described.

(1) Lock-up control using one common solenoid 22 as a shift solenoid for generating a solenoid output pressure PSOLB to a shift-up valve (B) 21 and a lock-up control valve 20 for achieving smooth and smooth lock-up. Since the sixth orifice 46 for controlling the release time of the torque converter release pressure PREL is provided in the drain oil passage 35 connected to the drain port 20j of the valve 20, advantages of cost, space, and weight can be achieved by sharing the solenoid. However, it is possible to provide a lock-up control device for an automatic transmission that achieves smooth and smooth lock-up control.

(2) Since the orifice (sixth orifice 46) is used as the release time adjusting means for controlling the release time of the torque converter release pressure PREL, only one orifice used in the hydraulic circuit of the automatic transmission needs to be added. There is no increase in cost, and there is no need to change the design of the hydraulic circuit of the automatic transmission.

(Other Embodiments) In the first embodiment, an example is shown in which a fixed orifice is used as the release time adjusting means for controlling the release time of the torque converter release pressure. An example using other means such as a variable orifice having a variable area or a flow control valve for controlling the drain flow rate may be used.

[0047]

According to the first aspect of the present invention, a lock-up clutch which is installed in a torque converter and which can directly connect an input / output shaft by fastening, and a solenoid output pressure is used as an operation signal pressure, and a lock-up clutch is used. When shifting from the released state to the engaged state, a lock-up control valve that achieves a smooth and smooth lock-up as a half clutch temporarily by drain adjustment of the torque converter release pressure, and the solenoid output pressure as the operating signal pressure,
A single shared solenoid that shares a shift valve that switches the oil path during gear shifting, a lockup solenoid that generates a solenoid output pressure to the lockup control valve, and a shift solenoid that generates a solenoid output pressure to the shift valve In the automatic transmission provided with the above, the drain oil passage connected to the drain port of the lock-up control valve is provided with a release time adjusting means for controlling the release time of the torque converter release pressure. A lock-up control device for an automatic transmission that achieves smooth and smooth lock-up control while achieving advantages in space and weight can be provided.

According to the second aspect of the present invention, the first aspect is provided.
In the lockup control device for an automatic transmission described above, since the orifice for adjusting the disconnection time is an orifice that narrows the cross-sectional area of the drain oil passage, in addition to the above-described effects, one orifice that is frequently used in the hydraulic circuit of the automatic transmission is added. It does not cause an increase in cost and does not require a design change of the hydraulic circuit of the automatic transmission.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing a lockup control device for 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 a diagram showing a shift solenoid operation table of the automatic transmission to which the lockup control device according to the first embodiment is applied.

FIG. 5 is a diagram showing an example of a shift point characteristic model of the hydraulic control device to which the lockup control device of the first embodiment is applied.

FIG. 6 is a circuit diagram showing a lock-up control device of the automatic transmission according to the first embodiment.

FIG. 7 is OFF in the lock-up control device according to the first embodiment.
It is a solenoid output pressure characteristic figure with respect to DUTY%.

FIG. 8 is a schematic diagram showing a conventional lockup control device for an automatic transmission.

FIG. 9 is a characteristic diagram of a torque converter release pressure with respect to a solenoid output pressure in a lock-up control device for a conventional automatic transmission.

FIG. 10 is a characteristic diagram of a torque converter release pressure with respect to a solenoid output pressure in a lock-up control device using a conventional shared solenoid.

FIG. 11 is a control image diagram when lock-up control is on / off control in a conventional lock-up control device using a shared solenoid.

[Explanation of symbols]

 a Torque converter b Lock-up clutch c Lock-up control valve d Shift valve e Shared solenoid f Drain port g Drain oil passage h Discharge time adjusting means (orifice)

Claims (2)

[Claims] 1. A lock-up clutch installed in a torque converter and capable of directly connecting an input / output shaft by engagement, and a solenoid output pressure being used as an operation signal pressure to shift the lock-up clutch from a disengaged state to an engaged state. A lock-up control valve that temporarily and smoothly achieves a smooth and smooth lock-up as a half-clutch by drain adjustment of the torque converter release pressure, and a shift valve that uses the solenoid output pressure as the operating signal pressure and switches the oil path during gear shifting. An automatic transmission comprising: a lock-up solenoid that generates a solenoid output pressure to the lock-up control valve; and a single shared solenoid that shares a shift solenoid that generates a solenoid output pressure to the shift valve. The lock-up control A drain oil passage connected to the drain port of the lube, the lock-up control apparatus for an automatic transmission, characterized in that a dropout time adjustment means controls the loss time of the torque converter release pressure. 2. A lock-up control device for an automatic transmission according to claim 1, wherein said disconnection time adjusting means is an orifice for reducing a sectional area of a drain oil passage. apparatus.