JPS6230607Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a control device for an automatic transmission for a vehicle.

Automatic transmissions for vehicles that combine a hydraulic torque converter and a gear transmission mechanism are widely used. Some devices are known that include a lockup clutch that is directly connected to the lockup clutch. Such a hydraulic torque converter with a lock-up clutch usually has a first and a second port, and the lock-up clutch is engaged when hydraulic pressure is supplied from the first port and the second port is drained. to mechanically connect the input shaft and output shaft, and conversely, when hydraulic pressure is supplied from the second port and the first port is drained, the lock-up clutch is released and the input shaft is connected mechanically. and the output shaft are interlocked and connected with a certain degree of flexibility via a fluid coupling structure. On the other hand, a gear transmission mechanism usually includes a plurality of frictional engagement devices controlled by hydraulic pressure, and gears are changed by switching the engagement of these frictional engagement devices.

In an automatic transmission for a vehicle having such a torque converter with a lock-up clutch and a gear transmission mechanism, hydraulic pressure is normally supplied to one of the frictional engagement devices, and the gear transmission mechanism shifts to the corresponding one gear stage. (normally the highest speed gear or the highest speed gear and the next speed gear), the hydraulic pressure supplied to the one frictional engagement device is supplied as the control signal hydraulic pressure to the lock-up clutch control valve. A control device connects the first port of the torque converter to a hydraulic source and connects the second port to a drain, thereby causing the gear transmission mechanism to move to the highest speed or highest speed. When shifting between a speed gear and the next speed gear, the automatic transmission is operated with the lock-up clutch engaged.

In a vehicle automatic transmission including such a lock-up clutch, the engagement or release of the lock-up clutch and the corresponding engagement or release of the one frictional engagement device are maintained at appropriate timings. It is important that this is done in order to soften the shifting shock. In other words, the hydraulic torque converter has the function of absorbing sudden torque fluctuations and softening the shift shock when the lock-up clutch is released, but when the lock-up clutch is engaged, it absorbs such sudden torque fluctuations. Therefore, it is preferable that the lock-up clutch is engaged after the engagement of the corresponding frictional engagement device is completed, and the lock-up clutch is released after the corresponding one of the frictional engagement devices is completed. Preferably, it is released prior to releasing the frictional engagement device.

The present invention focuses on the above-mentioned situation in automatic transmissions for vehicles that include a lock-up clutch, and provides a control device for automatic transmissions for vehicles that controls the engagement and disengagement of the transmission shock, especially the lock-up clutch. The purpose of this invention is to provide improvements in reducing shift shocks during gear shifts accompanied by.

According to the present invention, the present invention has a first port and a second port, and the second port is engaged when hydraulic pressure is supplied from the first port and the second port is drained. a torque converter that includes a lock-up clutch configured to be released when more hydraulic pressure is supplied and the first port is drained; and a gear transmission mechanism that changes gears by switching engagement of a friction engagement device. A hydraulic control device for an automatic transmission for a vehicle has a control port, and when hydraulic pressure is supplied to the control port, the hydraulic pressure to the torque converter is supplied to the first port. The second port is connected to a drain oil passage, and when oil pressure is not supplied to the control port, the oil pressure to the torque converter is supplied to the second port, and the first port is connected to the drain oil passage. a lock-up clutch control valve that is switched to control the lock-up clutch, a shift valve that controls the supply of hydraulic pressure to one of the frictional engagement devices, and a first oil that connects the one frictional engagement device and the shift valve. a second oil passage connecting the first oil passage to the control port and supplying the same hydraulic pressure to the control port as the oil pressure supplied to the one frictional engagement device; A throttle element provided in the middle of the oil passage responds to the oil pressure of the one frictional engagement device, and when the oil pressure is less than a predetermined value, the control port is directly connected to the drain oil passage, and the control port is connected directly to the drain oil passage when the oil pressure is greater than the predetermined value. This is achieved by a control device having a drain control valve that shuts off communication between the control port and the drain oil passage.

According to the above configuration, when the hydraulic pressure of one frictional engagement device increases to a predetermined value when the one frictional engagement device is engaged to achieve a specific gear stage, the drain control valve is switched and the one frictional engagement device is engaged. The same hydraulic pressure as the hydraulic pressure of the friction engagement device is transmitted to the control port of the lock-up clutch control valve with a time delay due to the pressure transmission delay effect by the throttle element, and the switching set pressure of the drain control valve and the throttle degree of the throttle element are are set to appropriate values in advance, so that the lock-up clutch is always engaged after the engagement of the one friction engagement device is completed, and the lock-up clutch is engaged during the engagement of the one friction engagement device. engagement is reliably avoided. When the hydraulic pressure of the one frictional engagement device drops to a predetermined value when the one frictional engagement device is released, the drain control valve is switched to reduce the hydraulic pressure applied to the control port of the lock-up clutch control valve. The drain is discharged rapidly from the drain control valve without being subjected to the pressure transmission delay effect by the throttle element, so that the lock-up clutch is always released before the release of the one frictional engagement device is completed, and the It is reliably avoided that the lock-up clutch remains engaged until after the release of one frictional engagement device has been completed. Further, according to the above-described configuration, since the hydraulic pressure applied to the control port of the lock-up clutch control valve is the same as the hydraulic pressure supplied to the one frictional engagement device,
Even if the lock-up clutch control valve fails, the one frictional engagement device is engaged so that the lock-up clutch can be engaged only when a specific gear is achieved. This prevents the lock-up clutch from being inadvertently engaged at times other than when a gear is achieved, thereby providing a so-called failsafe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing one embodiment of a control device for a vehicle automatic transmission according to the present invention together with the automatic transmission. In the figure, the automatic transmission includes a hydraulic torque converter 1 and a gear transmission mechanism 2. The torque converter 1 is constructed as a torque converter with a lock-up clutch and includes a lock-up clutch 3. Such a torque converter with a lock-up clutch is already known per se and has a housing 4, which is connected to an input shaft 5 and driven by the input shaft to rotate around a rotation axis X--X. It is becoming more and more like this. A pump impeller 6 is integrally connected to the housing 4, and the fluid pumped by the pump impeller as it rotates flows through a toroidal annular passage constituted by the pump impeller, the turbine liner 7, and the stator 8. It is now being circulated through the water. The turbine liner 7 is connected to the output shaft 9, and the stator 8 is supported by a fixed support part 11 via a one-way clutch 10.

In the torque converter 1, when hydraulic pressure is supplied from the first port 12 and the second port 13 is drained, hydraulic pressure is generated in the chamber 14 including the toroidal annular passage, and thereby the lock-up clutch 3 is pressed against the end wall 4a of the housing 4, and the lock-up clutch is engaged, so that the input shaft 5 and the output shaft 9 are mechanically directly connected, and conversely, the second When hydraulic pressure is supplied from the port 13 and the first port 12 is drained, a hydraulic pressure is generated in the chamber 15, which causes the lock-up clutch 3 to be separated from the end wall 4a of the housing, and the input shaft 5 and output shaft 9 are adapted to be fluidly drivingly connected by fluid circulating through the aforementioned toroidal annular passage including pump impeller 6, turbine liner 7, and stator 8.

The gear transmission mechanism 2 itself is already known in various configurations, and generally includes a multi-speed gear mechanism including a planetary gear mechanism and a drive train in the gear mechanism to switch gears in several ways. It includes several frictional engagement devices to achieve this. In the figures, one such friction engagement device is schematically indicated at 16. In this case, when the frictional engagement device 16 is engaged, the gear transmission mechanism 2 is set to the highest speed stage.

Reference numeral 17 denotes a hydraulic control device for controlling the operation of an automatic transmission comprising a torque converter 1 with a lock-up clutch and a gear transmission mechanism 2, and is itself already known in various forms. Such a hydraulic control device includes an oil reservoir 18
The oil pumped up and pressurized by the oil pump 19 is regulated to a predetermined line oil pressure by the line oil pressure control valve 20, and the line oil pressure is used to set the automatic transmission by the manual switching valve 21. At the same time as switching to various hydraulic circuits depending on the range, the throttle oil pressure control valve 22 generates throttle oil pressure in accordance with the amount of depression of the accelerator pedal, while the governor oil pressure control valve 23 increases it in accordance with the vehicle speed. The governor oil pressure is generated, and the 1st-2nd speed shift valve 2 is operated based on the equilibrium relationship between the throttle oil pressure and the governor oil pressure.
4. Switch the 2-3 speed shift valve 25, etc., switch the supply of hydraulic pressure to the aforementioned plurality of frictional engagement devices included in the gear transmission mechanism 2, and shift the gear transmission mechanism 2 to the position of the vehicle at that time. It is designed to switch to the gear most suited to the driving conditions. In the illustrated embodiment, the frictional engagement device 16 is as described above.
When it is engaged, the gear transmission mechanism 2
is set to the highest speed stage, in this case 2
- When the third speed shift valve 25 is upshifted, hydraulic pressure is supplied through the oil passage 27.

FIG. 2 shows an example of a speed change pattern of the gear speed change mechanism 2 whose operation is controlled by the hydraulic control device 17. In this diagram, the shift line 1→2 is the first
This is an upshift line that changes from the speed gear to the second speed gear, and conversely, the gear shift line 2→1
This is a downshift line where a downshift from the speed gear to the first speed gear is performed. Similarly, shift lines 2→3 and 3→2 are an upshift line and a downshift line between the second speed stage and the third speed stage, respectively.

Further, a throttle element 46 and a check valve 47 are provided in parallel in the middle of the oil passage 27, and an accumulator 48 is also provided.

Torque converter with lock-up clutch 1
is supplied with hydraulic pressure from a hydraulic control device 17 via an oil passage 28 and a lock-up clutch control valve 29. Lock-up clutch control valve 2
9 is a bore 31 formed in the housing 30;
It has a spool 32 that slides inside the control port 33, and when the control port 33 is not supplied with oil pressure of a predetermined value or higher, the spool is displaced upward in the figure by the action of the compression coil spring 34, and the control port 33 When a hydraulic pressure equal to or higher than a predetermined value is supplied to , it is displaced downward in the figure against the action of the compression coil spring 34 . The hydraulic pressure supplied to the port 36 of the lock-up clutch control valve 29 via the oil passage 28 is such that when the hydraulic pressure above a predetermined value is not supplied to the control port 33 and the spool 32 is in the upper switching position in the figure, It is transmitted to port 37, from which it is supplied to second port 13 of the torque converter via oil line 38. At this time, the port 40 connected to the first port 12 of the torque converter via the oil passage 39 communicates with the port 41, and an oil cooler 42 is connected to the port 41 on the way.
It is designed to be drained through a drain oil path 43 including a drain oil passage. On the other hand, when hydraulic pressure is supplied to the control port 33 of the lock-up clutch control valve, the hydraulic pressure supplied to the port 36 is supplied to the port 40 from which it passes through the oil passage 39 to the first terminal of the torque converter. supplied to port 12,
At this time, the second port 13 of the torque converter is connected to the drain port 44 via the oil passage 38 and port 37.
It is now connected to.

The control port 33 is connected to the throttle element 46 via the oil passage 35.
It is connected in the middle of the oil passage 27 on the side of the friction engagement device 16 from the parallel circuit portion of the check valve 47 and the friction engagement device 16 . The oil passage 35 has a throttle element 49 in the middle thereof,
Further, the throttle element is connected to a drain control valve 51 via an oil passage 50 branching from the control port 33 side. The drain control valve 51 is configured as a solenoid valve, and when the electromagnetic coil 52 is energized, the valve element 53 is moved to an upper position to open the valve port 54 and direct the oil passage 35 to the drain passage 5.
5, and when the electromagnetic coil 52 is not energized, the valve element 53 is displaced to the lower position, thereby closing the valve port 54 and opening the oil passage 3.
5 from the drain passage 55. Further, a throttle element 56 is provided in the middle of the oil passage 50 to control the amount of drain oil.

Current from a power source 57 is selectively supplied to the electromagnetic coil 52 via a switch 58. The opening and closing of the switch 58 is controlled by a control device 59. Control device 59
is inputted with the vehicle speed data detected by the vehicle speed sensor 60 and the signal generated by the pressure switch 61,
Based on these, the opening and closing of the switch 58 is controlled. The hydraulic switch 61 is the throttle element 46
and the check valve 47 in response to the oil pressure of the oil passage 27 on the side of the friction engagement device 16, that is, substantially the same oil pressure as the oil pressure of the friction engagement device 16,
For example, when the oil pressure is equal to or higher than a predetermined value _P1 , an on signal is generated.

When upshifting from the second speed stage to the third speed stage, the control device 59 outputs a signal to open the switch 58 when the vehicle speed is above a predetermined value _V2 and the hydraulic switch 61 is generating an on signal, and when the vehicle is upshifted from the second speed stage to the third speed stage. Sometimes it outputs a signal to close the switch 58, and also outputs a signal to close the switch 58.
When downshifting from a speed gear to a second speed gear, the vehicle speed is equal to or higher than a predetermined value V ₁ (V ₁ <V ₂ ) and the hydraulic switch 6 is turned off.
When switch 1 is outputting an on signal, it outputs a signal to open switch 58, and at other times, switch 5
It is designed to output a signal to close 8.

By controlling the opening and closing of the switch 58 as described above, the drain control valve 51 opens and closes in accordance with the vehicle speed and throttle opening as shown in FIG. That is, the operating characteristics of the drain control valve 51 follow the shift diagram shown in FIG.

In the configuration of the automatic transmission for a vehicle and the hydraulic control device therefor as described above, when the speed of the vehicle is increased and the operating state thereof reaches a state suitable for traveling in the highest speed gear, the shift valve 25 is upshifted, The supply of hydraulic pressure to the friction engagement device 16 to which no hydraulic pressure had been supplied until then is started. As a result, the hydraulic pressure generated in the frictional engagement device 16 increases at a certain speed in accordance with the degree of restriction determined by the restriction element 46, as shown by the solid line in FIG. In FIG. 4, t ₁ is the time point at which hydraulic pressure starts to be supplied to the friction engagement device 16, and t ₄ is the time point at which hydraulic pressure starts to be supplied to the friction engagement device 16.
The respective points indicate the completion of engagement. At this time, even if the vehicle speed is above the predetermined value _V2 , if the oil pressure formed in the friction engagement device 16 is below the predetermined value _P1 , the drain control valve 51 is open and the oil passage 35 is closed. The oil pressure at the control port 33 is drained and the oil pressure at the control port 33 does not substantially increase. Therefore, at this time, the lock-up clutch control valve 29 is in the upper switching position in FIG. It is in a state of freedom. When the oil pressure in the friction engagement device 16 rises above a predetermined value _P1 at time _t2 , the oil pressure switch 61
generates an on signal. At this time, the vehicle speed sensor 60
If the vehicle speed detected by is equal to or higher than the predetermined value _V2 , the drain control valve 51 closes. As a result, the oil pressure in the oil passage 27 passes through the oil passage 35 and reaches the throttle element 4.
9 to the control port 33 while giving a pressure transmission delay effect, whereby the control port 33
The oil pressure begins to rise at time _t2 , as shown by the dash-dotted line in FIG. The oil pressure in the control port 33 gradually increases with a certain time delay relative to the oil pressure in the oil passage 27 in accordance with the degree of restriction determined by the restriction element 49. By appropriately setting the hydraulic pressure setting of the hydraulic switch 61 and the degree of restriction of the throttle element 49, the hydraulic pressure at the control port 33 is adjusted at time _t5 after the engagement of the frictional engagement device 16 is completed. The switching oil pressure becomes higher than the setting oil pressure, which causes the lock-up clutch control valve 2 to
9, the spool 32 is switched from the upper switching position in FIG. The supply is then switched to the first port 12, whereby the lock-up clutch 3 is engaged after the frictional engagement device 16 has completed its engagement. Therefore, when the frictional engagement device 16 engages, the torque converter 1 is still in a state where the lockup clutch 3 is released and flexible power transmission by fluid is being performed, so that the frictional engagement is performed. A shift shock in changing the gear position of the gear transmission mechanism 2 due to the engagement of the device 16 is absorbed by the torque converter 1, and a shift with a small shift shock is performed.

FIG. 5 shows torque fluctuations during upshift. As shown by the broken line in FIG. 3, a substantial hydraulic pressure is supplied to the control port 33 simultaneously with the start of the supply of hydraulic pressure to the frictional engagement device 16, and the engagement of the frictional engagement device 16 is completed at time t ₄ An earlier time t ₃
When the engagement of the lock-up clutch 3 is completed, a large torque fluctuation occurs as shown by the broken line in FIG. 5, but when the present invention is used, a large torque fluctuation occurs as shown by the solid line. First, the gear shift shock becomes smaller.

When the operating condition of the vehicle changes and the gear transmission mechanism 2 is in a state where it should be downshifted from the highest gear to another gear, the shift valve 25 is switched and the oil passage 27 is connected to a drain port (not shown). connected to. At this time, the oil pressure of the frictional engagement device is drained through the throttle element 46 and the check valve 47, so that the oil pressure decreases relatively rapidly as shown by the solid line in FIG. In FIG. 6, t ₆ is the time when the hydraulic pressure of the friction engagement device 16 starts draining, and t ₁₀
1 and 2 respectively indicate the point in time when the frictional engagement device 16 is completely released. At this time, the oil pressure in the control port 33 is also drained. At this time, the hydraulic pressure in the control port 33 is drained via the throttle element 49, which is slower than in the frictional engagement device 16, but the hydraulic switch 61 causes the hydraulic pressure in the oil passage 27 to reach a predetermined level at time _t7 . When it is detected that the value is less than or equal to the value P ₁ , the drain control valve 51 opens, whereby the hydraulic pressure at the control port 33 is rapidly drained without being affected by the pressure transmission delaying effect of the throttle element 49 . As a result, the lock-up clutch control valve 29 is early switched from the lower position shown in _FIG . will be carried out. Thus, when the friction engagement device 2 is downshifted, the torque converter 1 is in a fluidly connected state, and the shift shock that occurs when the gear transmission mechanism 2 is downshifted is absorbed by the torque converter.

FIG. 7 shows torque fluctuations during downshift. If the drain control valve 51 does not open during a downshift, the oil pressure at the control port 33 will gradually and slowly decrease as shown by the broken line in FIG. The shifting point is delayed to _t9 , and at this time large torque fluctuations occur as shown by the broken line in FIG. becomes smaller.

As described above, according to the present invention, the lock-up clutch is engaged and the torque converter is engaged to shift the gear to a gear that is operated in a directly connected state, and to shift from the gear to another gear that does not use the lock-up clutch. During gear shifting, it is ensured that the lock-up clutch is always released when a gear change occurs in the gear transmission mechanism, thereby absorbing the shift shock in the gear transmission mechanism in the torque converter. , it will be appreciated that small shifting of the shifting shock can be achieved.

It will be apparent to those skilled in the art that various modifications can be made to the illustrated embodiment without departing from the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of a control device for a vehicle automatic transmission according to the present invention together with the automatic transmission, FIG. 2 is a diagram showing a shift pattern of a gear transmission mechanism, and FIG. 3 Figure 4 is a diagram showing the open and closed regions of the drain control valve, Figure 4 is a diagram showing hydraulic characteristics during upshifting, Figure 5 is a diagram showing torque fluctuations during upshifting, and Figure 6 is during downshifting. FIG. 7 is a diagram showing the hydraulic characteristics of the engine, and FIG. 7 is a diagram showing torque fluctuations during downshift. DESCRIPTION OF SYMBOLS 1... Torque converter, 2... Gear transmission mechanism, 3... Lock-up clutch, 4... Housing, 4a... End wall of housing, 5... Input shaft, 6... Pump impeller, 7... Turbine Runner, 8... Stator, 9... Output shaft, 10... One-way clutch, 11... Fixed support part, 12... First port, 13... Second port, 14, 15
...Chamber, 16...Friction engagement device, 17...Hydraulic control device, 18...Oil reservoir, 19...Oil pump, 20...Line hydraulic control valve, 21...
Manual switching valve, 22... Throttle hydraulic control valve, 2
3... Governor hydraulic control valve, 24... 1-2 speed shift valve, 25... 2-3 speed shift valve, 27, 28...
...Oil passage, 29...Lock-up clutch control valve,
32... Spool, 33... Control port, 34...
...Compression coil spring, 38, 39...Oil passage, 42...
... Oil cooler, 46 ... Throttle element, 47 ... Check valve, 48 ... Accumulator, 49 ... Throttle element, 50 ... Oil passage, 51 ... Drain control valve, 52
... Electromagnetic coil, 53 ... Valve element, 54 ... Valve port, 55 ... Drain passage, 56 ... Throttle element,
57... Power supply, 58... Switch, 59... Control device, 60... Vehicle speed sensor, 61... Oil pressure switch.

Claims (1)

[Scope of utility model registration request] It has a first and a second port, and is engaged when hydraulic pressure is supplied from the first port and the second port is drained, and the hydraulic pressure is supplied from the second port and the first port is drained. Hydraulic pressure for an automatic transmission for a vehicle, comprising a torque converter including a lock-up clutch configured to be released when the lock-up clutch is moved, and a gear transmission mechanism in which gears are changed by switching engagement of a friction engagement device. The control device has a control port, and when hydraulic pressure is supplied to the control port, the hydraulic pressure for the torque converter is supplied to the first port, and the second port is connected to the drain oil path. a lock-up clutch control valve that is switched to supply hydraulic pressure to the torque converter to the second port and connect the first port to a drain oil passage when no hydraulic pressure is supplied to the control port; a shift valve that controls the supply of hydraulic pressure to one of the engagement devices; a first oil path that connects the one frictional engagement device and the shift valve; a second oil passage that is connected to the control port and supplies the same hydraulic pressure as the one that is supplied to the one frictional engagement device to the control port; a throttle element provided in the middle of the second oil passage; In response to the oil pressure of one frictional engagement device, when the oil pressure is less than a predetermined value, the control port is directly connected to the drain oil passage, and when the oil pressure is more than the predetermined value, communication between the control port and the drain oil passage is established. A control device having a drain control valve that shuts off.